Extracellular ATP Signaling as a Proposed Mechanistic Link to Cellular Senescence in Cardiovascular Diseases

Abstract

Cellular senescence represents a critical pathological process involved in the progression of cardiovascular diseases (CVDs). Senescent endothelial cells, cardiomyocytes, vascular smooth muscle cells (VSMCs), and immune cells can promote inflammatory responses, oxidative stress, extracellular matrix (ECM) degradation, and fibrotic remodeling through the senescence-associated secretory phenotype (SASP). Beyond its fundamental role in intracellular energy metabolism, adenosine triphosphate (ATP) can also be released into the extracellular environment under conditions such as ischemia–reperfusion injury (IRI), mechanical stress, inflammatory stimulation, and cellular damage, where it participates in cellular stress responses through P2X/P2Y purinergic receptors. This article proposes the hypothesis that ATP-induced cellular senescence (AICS) contributes to CVD progression, suggesting that sustained or abnormally enhanced extracellular ATP signaling may promote cardiovascular cell senescence through disruption of Ca²⁺ homeostasis, mitochondrial reactive oxygen species (ROS) accumulation, activation of DNA damage response (DDR) pathways, NLRP3 inflammasome activation, enhanced NF-κB signaling, and persistent maintenance of the SASP. However, ATP signaling is highly dependent on its concentration, exposure duration, receptor subtype, and cellular context, and therefore cannot be simply regarded as a pro-senescence signal. Further studies using CVD-specific models and human pathological samples are required to establish the causal relationship among ATP/P2 receptor activation, cellular senescence burden, and disease progression.

Introduction

CVDs remain a leading contributor to global mortality and disease burden, with their persistent prevalence closely associated with population aging, increasing metabolic risk factors, and insufficient control of modifiable risk determinants.¹ Unlike traditional single-factor models of disease pathogenesis, the initiation and progression of CVDs are driven by the long-term interplay among hemodynamic disturbances, metabolic dysregulation, oxidative stress, sterile inflammation, alterations in cellular fate, and tissue remodeling.² Clinical evidence from anti-IL-1β therapy demonstrating reduced recurrence of cardiovascular events further supports the concept that inflammation is not merely an accompanying phenomenon but a therapeutically targetable pathological process actively involved in CVD development and progression.³ This paradigm shift highlights the importance of identifying shared pathological mechanisms across different diseases and cell types to better understand the persistent progression of cardiovascular disorders.

Cellular senescence provides an important biological framework for understanding the interplay among aging, chronic inflammation, metabolic dysfunction, and cardiovascular remodeling. In proliferative cell populations, senescence is characterized by stable cell-cycle arrest, accompanied by the upregulation of markers such as p16^INK4a and the establishment of a SASP. Although this program plays physiological roles in tumor suppression, embryonic development, and wound repair, persistent accumulation of senescent cells in adult tissues can contribute to age-related functional decline.⁴ Within the cardiovascular system, senescent cells are not merely in a state of irreversible growth arrest; rather, they actively reshape the tissue microenvironment through the secretion of inflammatory cytokines, chemokines, matrix-remodeling enzymes, and profibrotic mediators. The SASP produced by senescent VSMCs can promote monocyte recruitment, ECM degradation, and pro-inflammatory/pro-adhesive phenotypic changes in neighboring vascular cells. Following IRI, cellular senescence and SASP activation are also associated with enhanced inflammatory responses, impaired cardiac function, and adverse tissue remodeling.^5,6 These findings have established cellular senescence as a critical pathological dimension underlying vascular inflammation, plaque instability, myocardial fibrosis, and ventricular remodeling.

Extracellular ATP provides an important conceptual link between cardiovascular injury signals and the activation of cellular senescence programs. Within the cardiovascular injury microenvironment, ATP can transition from an intracellular energy metabolite to an extracellular danger-associated signaling molecule, thereby regulating vascular responses, inflammatory activation, and oxidative stress through purinergic P2 receptors. Shear stress-induced ATP release from endothelial cells can activate P2 receptor-dependent Ca²⁺ signaling, while the P2Y2/Gq/G11 signaling axis contributes to endothelial nitric oxide (NO) production, vascular tone regulation, and blood pressure homeostasis.^7,8 Meanwhile, P2X7R-mediated signaling has been implicated in mitochondrial ROS accumulation, inflammatory mediator release, and the development of cardiac senescence-associated phenotypes.^9,10 These findings suggest that extracellular ATP may function as an upstream signaling molecule connecting cardiovascular stress, chronic inflammation, and senescence-related pathological alterations, thereby providing a potential mechanistic basis for understanding CVD progression.

Prolonged ATP/P2 receptor signaling may facilitate the transition of cardiovascular cells from transient stress responses toward senescence-associated phenotypes through multiple mechanisms, including disruption of Ca²⁺ homeostasis, mitochondrial ROS accumulation, activation of DDR pathways, stimulation of the NLRP3 inflammasome and NF-κB inflammatory signaling, and maintenance of the SASP.^9–12 Accordingly, AICS is proposed here as a mechanistic hypothesis, suggesting that ATP/P2 receptor signaling may participate in the pathological continuum linking cardiovascular stress to cellular senescence, chronic inflammation, fibrosis, and tissue remodeling. However, the effects of ATP signaling are likely to vary depending on cell type, disease stage, and pathological context, and the causal relationship between ATP/P2 receptor activation, senescence burden, and CVD progression requires further validation.

This article focuses on the potential pathological role of sustained extracellular ATP signaling within the cardiovascular injury microenvironment. Conditions including ischemia, inflammation, mechanical stress, and metabolic disturbances can promote ATP release into the extracellular space, resulting in persistent activation of purinergic P2X/P2Y receptors.

Based on the proposed hypothesis, this article discusses AICS within an integrated framework encompassing molecular mechanisms, cardiovascular cell types, disease contexts, and therapeutic translation. At the molecular level, emphasis is placed on key regulatory nodes involved in ATP/P2 receptor signaling, including P2X/P2Y receptors, Ca²⁺ homeostasis, mitochondrial ROS accumulation, DDR, inflammasome activation, NF-κB signaling, and SASP regulation. At the cellular level, the potential roles of AICS are examined across major cardiovascular cell populations, including endothelial cells, cardiomyocytes, VSMCs, fibroblasts, and immune cells. At the disease level, representative cardiovascular conditions, including atherosclerosis, hypertension, coronary artery disease, myocardial infarction (MI), heart failure, atrial fibrillation, and vascular endothelial dysfunction, are discussed to explore the potential contribution of AICS pathways to disease progression. By integrating mechanistic evidence, disease-associated findings, and translational challenges, this article aims to systematically evaluate the potential relationship between AICS and CVD development, while providing a conceptual framework for future experimental validation of this hypothesis.^5,8,10,12

Molecular Mechanisms Underlying AICS

Cellular senescence is a stress-responsive state of permanent growth arrest in proliferating cells associated with persistent DNA damage responses and the acquisition of the senescence-associated secretory phenotype (SASP). While transient senescence can play beneficial roles in physiological functions such as tissue repair and tumor suppression, accumulation of persistent senescent-cell populations has been associated with chronic inflammation, matrix dysregulation, fibrotic remodeling and cardiac dysfunction.^5,6 Senescence is also cell-type dependent. Mature cardiomyocytes are terminally differentiated cells and cannot be assessed on the basis of the traditional paradigm of replicative senescence. Persistent DNA damage, mitochondrial dysfunction, impaired mitochondrial quality control, and senescence-associated secretory phenotypes may represent more appropriate features associated with accelerated cardiac aging, fibrosis, and adverse remodeling.^13,14 In this context, extracellular ATP/P2 receptor signaling might represent an upstream stress pathway regulating senescence-associated traits in cardiovascular cells.

Activation of Purinergic Receptor-Mediated Signaling

Extracellular ATP is an important damage-associated molecular pattern (DAMP) released during tissue injury, ischemia–hypoxia, inflammatory responses, and cellular damage or necrosis. Through P2X and P2Y purinergic receptors, extracellular ATP converts injury-related signals into intracellular stress responses, including disruption of Ca²⁺ homeostasis, inflammatory activation, oxidative stress, and mitochondrial dysfunction. Accordingly, the core ATP signal considered in the AICS hypothesis refers specifically to extracellular ATP acting through P2 purinergic receptors, whereas intracellular ATP depletion or impaired mitochondrial ATP production is treated here as a distinct manifestation of cellular energetic stress. It should be emphasized that ATP/P2 receptor signaling alone does not constitute a definitive criterion for cellular senescence; rather, it may contribute to the establishment of a pro-senescent microenvironment through the integration of multiple stress-associated pathways.^12,15,16 The proposed molecular framework of AICS is illustrated in Figure 1, while experimental models, mechanistic evidence, and cardiovascular implications of AICS are summarized in Table 1.

Figure 1.

Proposed model illustrating the role of extracellular ATP signaling in cellular senescence and cardiovascular microenvironmental remodeling. Extracellular ATP release is promoted in response to various cardiovascular stressors such as tissue injury, ischemia or inflammation. Sustained or abnormally elevated extracellular ATP may convert damage signals into multidimensional cellular stress responses through purinergic receptors, especially P2X7R and P2Y2R. P2X7R-related signaling may promote Ca²⁺ influx, K⁺ efflux and NLRP3 inflammasome activation, whereas P2Y2R-related signaling may participate in Ca²⁺ homeostasis disruption, inflammatory responses and vascular wall cell stress. Such pathways may intertwine with mitochondrial malfunction, ROS-dependent cell signaling, the release of mtDNA and DDR to form synergistic stress circuits. Prolonged activation of these networks may trigger canonical senescence pathways including the p53–p21 and p16^INK4a–Rb axes, thereby shifting cardiovascular cells from transient adaptive responses to those associated with senescence. Senescent cells, through the SASP, secrete IL-1β, IL-6, chemokines and MMPs which sustain local pathology by fueling inflammation, paracrine senescence and ECM remodeling. This integrated stress network may contribute to endothelial cell senescence, vascular smooth muscle cell remodeling and myocardial fibrosis, thereby further promoting atherosclerosis progression, vascular stiffening and cardiac dysfunction. Importantly, ATP/P2 receptor signaling alone does not establish cellular senescence. Its effects depend on ATP concentration and exposure duration, receptor subtype, cell type, and disease stage, and should be interpreted together with evidence of DNA damage, stable cell-cycle arrest in proliferative cell populations, SASP activation, and functional impairment. In this schematic, solid arrows denote experimentally supported relationships within individual cited systems, whereas dashed arrows denote proposed or inferred cross-model connections. Dashed connections should not be interpreted as a complete causal pathway established in a single cardiovascular model.

Table 1.

Experimental Models, Mechanistic Evidence and Cardiovascular Implications Related to AICS

Biological Context	Purinergic Signaling Nodes	Experimental Models and Cell Types	Experimental Interventions	Senescence-Associated Readouts	Mechanistic Insights and Cardiovascular Relevance	References
Cardiomyocyte senescence	P2X7 receptor (P2X7R)	HL-1 cardiomyocyte model	D-galactose-induced senescence and P2X7R inhibition (A438079)	p53, p21, and p16INK4a	P2X7R deficiency/inhibition attenuates cardiac aging-associated cardiomyocyte senescence	[10]
P2Y14-regulated progenitor cell senescence	P2Y14–Gi/o stress-response signaling;17 UDP-glucose–P2Y14R signaling18	P2ry14-deficient mouse HSPCs;17 human cardiac progenitor cells (hCPCs) derived from HF patients18	P2ry14 deletion with radiation stress;17 P2Y14R overexpression and UDP-glucose stimulation18	SA-β-gal activity, p16INK4a expression, and mitochondrial ROS in HSPCs;17 senescence-associated morphology, p16INK4a, p53, p21, and mitochondrial ROS in hCPCs18	Inferred link: P2Y14 deficiency increases susceptibility to stress-induced HSPC senescence through Gi/o-associated ROS and p38 MAPK/JNK signaling,17 whereas P2Y14R overexpression attenuates senescence-associated phenotypes and enhances proliferation, migration, and stress resistance in HF-derived hCPCs,18 suggesting that P2Y14-mediated regulation of stress-induced senescence may extend from hematopoietic progenitors to cardiac progenitor cells.	[17,18]
HFpEF-associated cardiac remodeling and senescence-associated changes	ATP–P2X7R–NLRP3 inflammasome signaling	3-hit HFpEF mice; H9c2 cardiomyocytes; neonatal rat ventricular cardiomyocytes	RDN, ATP stimulation, P2X7 knockdown, A438079, and MCC950	Increased p21-positive nuclei and γH2AX in HFpEF hearts	Activation of ATP–P2X7R–NLRP3 signaling was associated with myocardial inflammation, oxidative stress, fibrosis, cardiomyocyte hypertrophy, and diastolic dysfunction; P2X7R or NLRP3 inhibition attenuated cardiac remodeling and improved HFpEF-related functional abnormalities.	[19]
ATP/P2Y11R-mediated premature senescence and endothelial P2Y2R-dependent vascular responses in atherosclerosis	ATP–P2Y11R–PLC–Ca2⁺–mitochondrial ROS signaling;20 ATP/UTP–P2Y2R signaling21	WI-38 human diploid lung fibroblasts;20 endothelial-specific P2Y2R-deficient ApoE−/− mice and primary vascular endothelial cells21	ATP stimulation and P2Y11R inhibition with NF-157;20 endothelial-specific P2Y2R deletion and ATPγS/UTPγS stimulation of aortic rings21	SA-β-gal activity, senescence-associated morphology, p-p53, p21, p16, γH2AX, and reduced BrdU incorporation;20	Inferred link: ATP/P2Y11R signaling induces premature senescence in WI-38 fibroblasts through PLC-dependent Ca2⁺ release, mitochondrial Ca2⁺ accumulation, and ROS generation;20 whereas endothelial P2Y2R signaling regulates nucleotide-dependent vasodilation, vascular inflammation, endothelial barrier function, and atherosclerotic plaque phenotype21	[20,21]
Cardiomyocyte senescence in cardiac aging and diabetes-associated cardiac remodeling	P2X7R–HuR/TRIM26/NR4A1–mitophagy signaling10	Naturally aged and D-galactose-induced mouse cardiac aging models and HL-1 cardiomyocytes;10 T2DM rat models, H9C2 cardiomyocytes, and neonatal rat cardiomyocytes exposed to high glucose22	P2X7R knockout, pharmacological inhibition with A438079, and cardiomyocyte-specific P2X7R or NR4A1 overexpression;10 Rnd3 knockout or overexpression and STAT3 inhibition with S3I-201 under diabetic/high-glucose conditions22	SA-β-gal activity, p53, p21, p16, ROS, and mitophagy-associated changes;10 SA-β-gal activity, γH2AX, p53, p16, and SASP-related factors including MCP1, IL-1α, IL-6, and GDF1522	Inferred link: P2X7R promotes cardiac aging and cardiomyocyte senescence through HuR/TRIM26/NR4A1-dependent mitophagy impairment,10 whereas Rnd3 downregulation activates STAT3 signaling to promote diabetic cardiomyocyte senescence and dysfunction,22 converging on senescence-associated cardiac remodeling.	[10,22]
P2X7R-associated cardiomyocyte senescence and Ang II–induced cardiac remodeling	P2X7R–HuR/TRIM26/NR4A1–mitophagy signaling;10 Ang II–P2X7R–HuR–GPX4/HO-1 signaling23	Naturally aged and D-galactose-induced mouse cardiac aging models and HL-1 cardiomyocytes;10 Ang II–infused mice, primary cardiomyocytes, and H9c2 cells23	P2X7R knockout, A438079 treatment, and P2X7R or NR4A1 overexpression;10 Ang II stimulation with P2X7R knockout, A438079 treatment, or P2X7R silencing23	SA-β-gal activity, p53, p21, p16, ROS, and mitophagy-associated changes10	Inferred link: P2X7R promotes cardiac aging and cardiomyocyte senescence through HuR/TRIM26/NR4A1-dependent mitophagy impairment,10 whereas Ang II–P2X7R–HuR signaling promotes cardiomyocyte ferroptosis and cardiac remodeling through regulation of GPX4 and HO-1 mRNA stability,23 linking distinct P2X7R-dependent stress pathways to adverse cardiac remodeling.	[10,23]
Endothelial inflammatory activation and senescence in atherogenesis	ATP–P2X7R–Ca2⁺–p38 signaling;15 CDKN2A–CDK4/6 senescence signaling24	Atheroprone flow-conditioned HUVECs and murine aortic endothelium;15 ox-LDL-treated HUVECs and HFD-fed ApoE−/− mice24	BzATP stimulation, P2X7R inhibition with A438079, and P2X7R knockdown;15 CDKN2A knockdown and CDK4/6 inhibition with palbociclib24	Cell-cycle arrest, senescent morphology, ROS production, β-galactosidase activity/expression, and CDKN2A/CDK4/6 expression24	Inferred link: ATP/P2X7R–Ca2⁺–p38 signaling promotes endothelial inflammatory activation under atheroprone flow,15 whereas CDKN2A/CDK4/6 signaling drives endothelial senescence and atherogenesis,24 representing distinct endothelial mechanisms contributing to atherosclerotic progression.	[15,24]
ATP-mediated premature senescence and P2X7R-dependent plaque inflammation in atherosclerosis	ATP–P2Y11R–PLC–Ca2⁺–mitochondrial ROS signaling;20 ATP–P2X7R–caspase-1/IL-1β inflammasome signaling25	WI-38 human diploid lung fibroblasts;20 P2X7-competent and P2X7-deficient macrophages, P2X7+/+ LDLR−/− and P2X7−/− LDLR−/− mice, and human carotid plaques25	ATP stimulation and P2Y11R inhibition with NF-157;20 LPS priming followed by ATP stimulation and P2X7 deficiency25	SA-β-gal activity, senescence-associated morphology, p-p53, p21, p16, γH2AX, and reduced BrdU incorporation20	Inferred link: ATP/P2Y11R signaling induces premature senescence through PLC-dependent Ca2⁺ release and mitochondrial ROS generation in WI-38 fibroblasts,20 whereas ATP/P2X7R signaling activates caspase-1/IL-1β signaling in macrophages and promotes plaque inflammation and atherosclerosis,25 linking distinct ATP-responsive pathways to atherogenesis.	[20,25]
Macrophage inflammatory activation and senescence in atherogenesis	UDP/3P-UDP–P2Y6R signaling;26 lactate–GPR132–Src signaling27	THP-1 macrophages, primary mouse and human macrophages, and LDLR−/− mice with P2Y6-deficient bone marrow;26 RAW264.7 macrophages, BMDMs, diabetic Apoe−/− and Gpr132−/−Apoe−/− mice27	P2Y6 agonism with 3P-UDP, P2Y6 silencing, and P2Y6-deficient bone marrow transplantation;26 high-glucose or lactate exposure, GPR132 activation or deletion, and Src inhibition with saracatinib27	p16, p21, β-galactosidase activity, SASP-related gene expression, and senescent macrophage accumulation in plaques27	Inferred link: P2Y6 signaling promotes macrophage inflammatory cytokine responses and leukocyte-driven atherogenesis,26 whereas lactate–GPR132–Src signaling induces macrophage senescence, enhances ox-LDL uptake, and accelerates atherosclerosis,27 linking inflammatory and senescence-associated macrophage dysfunction to atherogenesis.	[26,27]
Macrophage foam-cell formation and senescence in atherogenesis	P2Y6R–PLCβ–SOCE–CALR signaling;28 p16INK4a-associated senescence and lipid-handling pathways29	Whole-body and macrophage-specific P2Y6R-knockout atherosclerosis models and macrophages;28 ox-LDL-treated THP-1 macrophages with p16INK4a overexpression29	P2Y6R deletion and pharmacological antagonism with thiamine pyrophosphate;28 p16INK4a overexpression followed by ox-LDL exposure29	SA-β-gal activity and SASP factors including IL-1α, TNF-α, and MMP929	Inferred link: P2Y6R promotes macrophage foam-cell formation through PLCβ/SOCE/CALR-dependent regulation of scavenger receptor A,28 whereas p16INK4a enhances foam-cell formation by increasing CD36 and LOX-1 expression, reducing cholesterol efflux, and promoting macrophage senescence,29 linking purinergic regulation and senescence-associated lipid handling to atherogenesis.	[28,29]
Inflammatory atrial remodeling and atrial cardiomyocyte senescence in atrial fibrillation	P2X7R–NLRP3 inflammasome signaling;30 p21/p16-associated senescence signaling31	Sterile pericarditis rat model of postoperative AF;30 human left atrial appendages and tachypaced HL-1 atrial cardiomyocytes31	P2X7R inhibition with Brilliant Blue G or A740003 and IL-1R blockade with anakinra;30 tachypacing and p21 knockdown in HL-1 cardiomyocytes31	SA-β-gal activity, p21, p16, p53, γH2AX, and SASP-related IL-1β and IL-6 expression31	Inferred link: P2X7R–NLRP3 inflammasome signaling promotes inflammatory atrial remodeling and AF susceptibility,30 whereas atrial cardiomyocyte senescence is associated with AF progression, SASP elevation, and altered sarcoplasmic reticulum proteins,31 linking inflammatory and senescence-associated remodeling in AF.	[30,31]

Among the P2 receptor family, the P2X7R represents a critical interface linking elevated extracellular ATP levels with inflammatory stress responses. P2X7R activation generally requires relatively high concentrations of ATP, making it particularly responsive to persistent stimulation under conditions such as ischemia, necrosis, and chronic inflammation. Upon activation, P2X7R promotes Na⁺ and Ca²⁺ influx as well as K⁺ efflux, with K⁺ depletion serving as a critical trigger for NLRP3 inflammasome assembly, caspase-1 activation, and maturation and release of IL-1β.^12,32,33 These findings indicate that the ATP/P2X7R axis has a strong capacity to amplify inflammatory responses; however, current evidence does not establish that P2X7R activation alone is sufficient to induce cellular senescence. Therefore, P2X7R is better considered an upstream signaling gateway that facilitates the formation of an ATP-driven senescence-associated microenvironment rather than a direct marker of cellular senescence.

P2X7R-mediated inflammasome activation can further interact with oxidative stress and mitochondrial dysfunction, creating a more persistent intracellular environment that favors the initiation of senescence programs. ATP stimulation of P2X7R promotes IL-1β release as well as the production of ROS and reactive nitrogen species (RNS), thereby contributing to oxidative tissue injury.³³ Meanwhile, P2X7R activation can facilitate the release of extracellular vesicles and mitochondria-associated components, while also altering mitochondrial network homeostasis in recipient cells.³⁴ These alterations may enhance DDR and stress kinase signaling, thereby creating conditions conducive to cell-cycle arrest mediated by the p53/p21 and p16/Rb pathways. More direct evidence from cardiovascular studies demonstrates that genetic P2X7R deficiency (P2X7R knockout) alleviates cardiac aging-associated phenotypes by enhancing mitophagy and improving mitochondrial quality control in cardiomyocytes.¹⁰ These findings support a regulatory role for P2X7R in cardiac aging-associated senescence and mitochondrial quality control, but do not establish sustained extracellular ATP elevation as the upstream trigger of these changes.

Beyond P2X7R, P2Y receptors can also translate extracellular nucleotide signals into stress responses in vascular wall cells. The P2Y2 receptor promotes Ca²⁺ influx through calcium release-activated calcium (CRAC) channels and activates downstream signaling pathways, including extracellular signal-regulated kinase (ERK) and p38 MAPK, thereby contributing to cytoskeletal remodeling and vascular cell migration.³⁵ In atherosclerosis models, P2Y2-deficient mice exhibit reduced expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) within atherosclerotic plaques, suggesting that the ATP/P2Y2 axis contributes to endothelial inflammatory activation and immune cell recruitment.³⁶ Consistent with these findings, endothelial cell-specific deletion of P2Y2R in ApoE^−/− mice reduced atherosclerotic lesion burden and macrophage infiltration while increasing smooth muscle cell and collagen content, resulting in a more stable plaque phenotype.²¹ In contrast, evidence regarding CD151/P2Y12-mediated regulation of platelet thrombus growth and stability primarily relates to thrombosis and plaque complications, with a relatively limited direct connection to cellular senescence.³⁷ Therefore, P2Y signaling is more appropriately considered a cooperative mechanism through which extracellular nucleotides regulate vascular inflammatory microenvironments and CVD progression, rather than independent evidence directly demonstrating AICS.

From the perspective of senescence biology, ATP/P2 receptor signaling should not be considered a direct determinant of cellular senescence, but rather an upstream regulatory mechanism that may create a cellular environment conducive to senescence induction through the activation of stress-related pathways. Atherosclerosis-prone disturbed flow has been shown to induce endothelial inflammatory responses through an ATP-dependent P2X7R–p38 signaling pathway.¹⁵ In addition, NF-κB-associated regulatory mechanisms can modulate oxLDL- or LPS/ATP-induced NLRP3 inflammasome activation, pyroptosis, and the release of IL-1β and IL-18.³⁸ These findings primarily support the involvement of the ATP/P2 receptor axis in inflammatory stress responses, but do not provide direct evidence that ATP signaling alone is sufficient to establish a stable senescent phenotype. Notably, p38 MAPK, ERK, and NF-κB signaling pathways also function as key upstream regulatory networks involved in SASP establishment, cell-cycle arrest, and maintenance of senescence-associated phenotypes, whereas the p53/p21 and p16/Rb pathways contribute to the stabilization and persistence of the senescence program.³⁹

Therefore, P2 receptor-mediated signaling represents an important membrane-level mechanism through which extracellular ATP initiates cardiovascular cellular stress responses. Persistent ATP exposure may activate P2X7R and P2Y2R, integrating Ca²⁺ dysregulation, inflammasome activation, mitochondrial dysfunction, and enhanced MAPK/NF-κB signaling, thereby linking extracellular stress signals with DDR, cell-cycle arrest, and SASP formation. Current evidence more strongly supports the role of the ATP/P2 receptor axis in amplifying inflammation and vascular stress, while whether it is sufficient to independently induce stable cellular senescence remains to be determined through comprehensive assessment using established senescence markers.

Oxidative Stress and DNA Damage-Driven Cellular Senescence

Following P2 receptor activation, disruption of Ca²⁺ homeostasis and alterations in mitochondrial metabolism represent critical steps in the progression of ATP-associated cellular stress responses. Persistent Ca²⁺ influx can increase mitochondrial workload, promote ROS production, and convert transient receptor activation into sustained oxidative stress. Studies on ATP-induced cell death (AICD) and ATP-associated cytotoxicity have demonstrated that dysregulated ATP homeostasis is accompanied by P2X7R-dependent Ca²⁺ influx, alterations in mitochondrial membrane potential, ROS generation, inflammasome activation, and ATP depletion, ultimately promoting cellular injury or death under severe stress conditions.^40,41 Therefore, abnormal ATP signaling may create a pathological environment conducive to DDR and senescence-associated alterations through progressive disruption of ionic homeostasis, mitochondrial function, and redox balance.

Mitochondrial Ca²⁺ uptake derived from the endoplasmic reticulum can promote ATP production and ROS generation, while ATP and ROS can in turn influence Ca²⁺ homeostasis, forming a reciprocal regulatory network involving Ca²⁺ transport, energy metabolism, and oxidative stress.⁴² This suggests that under conditions of sustained ATP stimulation or abnormal P2 receptor activation, increased intracellular Ca²⁺ loading may promote ROS accumulation by altering mitochondrial metabolic states. At the mitochondrial level, enhanced succinate oxidation mediated by succinate dehydrogenase and increased mitochondrial membrane potential can both contribute to elevated mitochondrial ROS production.⁴³ Furthermore, the metabolic interplay between the NLRP3 inflammasome, ROS generation, and mitochondrial electron transport chain activity indicates that inflammatory signaling and oxidative stress can establish a mutually reinforcing intracellular network.⁴⁴ Collectively, these findings suggest that ATP-associated Ca²⁺ disturbances and mitochondrial metabolic alterations may create a permissive environment for sustained ROS accumulation.

When ROS production exceeds the capacity of cellular antioxidant defenses and DNA repair systems, oxidative stress may shift from a transient metabolic fluctuation to a persistent DDR. ROS can regulate m6A modification levels by affecting the post-translational modification of ALKBH5, thereby inducing expression changes in genes involved in biological processes such as DNA damage repair.⁴⁵ These results suggest that oxidative stress can reshape DDR and repair networks. In conjunction with p38 MAPK signaling, ROS generation may also stimulate acceleration of the cell cycle and oxidative DNA damage that is related to proliferative stress.⁴⁶ More direct evidence shows that the induction of NOX4 expression by increased Ca²⁺ influx through cPKC activation also drives DNA damage and then p53-dependent cellular senescence and, consequently, cell death.⁴⁷ Excessive expression of thioredoxin-interacting protein (TXNIP) has also been associated with oxidative DNA damage and regulation of cellular senescence.⁴⁸ Hence, ROS ought not to be seen only as a mere byproduct of the stress responses energized by ATP. Rather than signaling early receptor-mediated stress-adapted responses, ROS might act as an important mediator that translates those signals into more permanent changes of cell fate mediated by oxidative DNA damage and the activation of genome instability response pathways.

ATP-associated cellular stress could be associated with an important step in the transition of DDR from transient signals to stable senescence-like states. In addition to telomere shortening-driven replicative senescence, oxidative stress can also induce oxidative base damage and replication-dependent telomere fragility, leading to telomere dysfunction even before obvious telomere shortening or loss of telomere protection.⁴⁹ Various senescence-inducing stimuli such as telomere shortening and oncogene activation can trigger senescence programs by damaging nuclear DNA.⁵⁰ Persistent DDR activates cell-cycle regulatory pathways including the p53/p21 and p16/Rb axes, enforcing the propagation of transient damage responses to permanent proliferative arrest. Additional models of stress provide evidence that ROS-induced oxidative damage and DNA damage are linked to p53-mediated as well as p16/Rb-mediated signaling pathways.⁵¹ However, since such models commonly include combinatorial apoptotic or other cell death pathways, they should be considered indirect mechanistic evidence of cellular senescence rather than direct proof. Therefore, DDR must be viewed as a central and seminal nexus of cell cycle regulation in the context of ATP-related cellular stress, rather than an effect downstream of cellular distress.

Mitochondrial dysfunction, together with hypoxia and inflammation, contributes to prolongation of ROS production and DNA damage signaling. Mitochondrial dysfunction is a common feature of senescent cells, exhibiting characteristics such as respiration-dependent energy metabolism impairment, ROS overproduction and loss of metabolic homeostasis.⁵² In this context, ROS can maintain cellular stress responses and aggravate mitochondrial injury, whereas DDR may drive activation of the p53/p21 and p16/Rb pathways that can push cells towards irreversible cell-cycle arrest. Thus, ATP-associated Ca²⁺ dysregulation and mitochondrial dysfunction may promote the emergence of senescence-associated phenotypes through ROS accumulation, DNA damage and cell-cycle arrest in cardiovascular cells. The persistent release of inflammatory mediators and ECM-remodeling factors that occur with this stress-induced state may thus also be linked to the later emergence and maintenance of the SASP.

Amplification of Inflammatory Signaling and Formation of the SASP Phenotype

Herein, senescent cells can no longer proliferate; however, in cardiovascular tissues, their pathological relevance lies in their ability to form the SASP, a multi-factorial condition characterized by the continuous remodeling of the local microenvironment. Over the past two decades, it has been reported that senescent endothelial cells, VSMCs, fibroblasts and immune cells can secrete many pro-inflammatory cytokines, chemokines and factors involved in ECM remodeling, contributing to local vascular inflammation as well as altering plaque stability, myocardial fibrosis and ventricular remodeling. Thus, SASP is an important link from single-cell senescence to the pathological processes at the tissue level.^5,6,53

The SASP is not a static secretory profile, but more of a variable phenotype that is influenced by cell type, senescence-inducing stimuli and the milieu of their surrounding tissue microenvironment. The main components are inflammatory cytokines, chemokines, matrix metalloproteinases (MMPs), and fibrosis-related mediators. Cellular senescence in VSMCs also can cause a pro-inflammatory secretory state with prolonged autocrine IL-1α signaling that is associated with upregulation of inflammatory cytokines, chemokines, and active MMP-9 release and collagen suppression alongside NF-κB-dependent expression of components involved in inflammasome activation.⁵ This secretory program supports an increase in local monocyte recruitment and induces bystander endothelial cells and VSMCs to acquire pro-adhesive and pro-inflammatory phenotypes. These findings reveal SASP as a major mechanism of action by which senescent vascular cells modulate inflammatory responses, ECM homeostasis, and inter-cellular communication at a local cardiovascular micro-environment.

SASP establishment has been shown to depend on integrated regulation of inflammatory signaling, metabolic states and transcriptional networks. Key regulatory axes of the pro-inflammatory SASP include inflammasome activation, IL-1 signaling, and NF-κB pathway activation. Notably, IL-1α expression is elevated and can trigger unique SASP-associated inflammatory programs—materializing a potential mechanistic link to the ATP/P2X7R/NLRP3 signaling circuit described above. Current evidence appears insufficient to show that ATP induces a full SASP program, but it remains possible that pro-inflammatory signaling persists through persistent NLRP3 activation, that such signaling promotes IL-1 signaling, or that the NF-κB pathway acts as an activator during the initiation and maintenance of the SASP. At the same time, metabolic reprogramming also affects both the strength and content of SASP. TRAP1-mediated metabolic reprogramming promotes SASP expression in VSMCs and expeditiously accelerates atherosclerotic development.⁵⁴ Furthermore, high levels of NAMPT expression and regulation of NAD metabolism by NAMPT are involved in the regulation of SASP. As producers of one component of the SASP, senescent cells may also secrete extracellular NAMPT, which is involved in AMPK and NF-κB signaling pathways to modulate pro-inflammatory secretory phenotypes.⁵⁵ These data hint that transient injury-related stimuli might be transformed into long-lasting secretory programs when ATP-associated inflammatory signaling integrates with metabolic dysregulation and the NF-κB transcription network. This raises the possibility that accumulation of extracellular ATP, chronic inflammation and maintenance of senescence-associated phenotypes are mechanistically linked in cardiovascular tissues.

After SASP establishment, senescence-associated signals can additionally spread within local tissues via both autocrine and paracrine mechanisms. Autocrine SASP signaling helps maintain the senescent inflammatory and secretory states in the senescent cells themselves, while paracrine SASP signaling acts on adjacent non-senescent neighbors, inducing DNA damage, inflammatory activation, or other age-related changes. Evidence from previous studies shows that IL-1α and IL-8 released by late-passage mesenchymal stem cells can induce paracrine senescence of early-passage mesenchymal stem cells via an NF-κB-dependent mechanism, and inhibition of NF-κB signaling can completely abolish this effect.⁵⁶ Moreover, senescent cells can activate canonical DDR in adjacent bystander fibroblasts through cell–cell contact and ROS-dependent pathways, and fibroblasts chronically exposed to senescent cells may also develop features of cellular senescence.⁵⁷ These data show that senescence responses in cardiovascular lesions may not be limited to initial damage sites but can spread via paracrine effects of the SASP, leading to chronic inflammation and maladaptive deterioration at the tissue level.

Accordingly, SASP signaling may amplify ATP/P2 receptor-associated cellular stress and sustain inflammatory and remodeling responses within cardiovascular tissues. Recent evidence suggests that ATP/P2 receptor signaling promotes inflammasome activation, oxidative stress, and NF-κB-dependent inflammatory transcription; on the other hand, SASP mediates vascular inflammation, ECM degradation and fibrotic remodeling. Importantly, the current evidence mainly indicates a mechanistic association of ATP signaling with the upstream regulatory network of the SASP; some data are not adequate to prove that ATP signaling alone induces an autonomous and stable SASP program in cardiovascular tissues.

Cell Type-Specific Mechanisms Linking AICS to CVD

At each step of various CVDs, ATP/purinergic signaling can affect different cells in a dissimilar manner. Conversely, its biological effects are largely context dependent and sensitive to cellular background, receptor expression patterns, stimulus strength and disease phase. While endothelial cells express the phenotypes of Ca²⁺ homeostasis alteration and diminished NO bioavailability in addition to an increasing degree of adhesion molecule expression, cardiomyocytes are associated with prominent ROS accumulation, mitochondrial dysfunction, faulty Ca²⁺ handling dynamics and metabolic stress responses. In addition, these cell type-specific responses may further couple with SASP formation and amplification of inflammation to remodel the cardiovascular microenvironment, together driving progression of atherosclerosis, fibrosis and heart failure. This dependence on cell type also applies to the operational definition of cellular senescence. Cell-cycle arrest in conjunction with DDR, senescence-associated secretory phenotype alterations, and functional impairment should characterize cellular senescence in proliferative vascular and stromal cells. Persistent DDR, impaired mitochondrial quality control, a non-canonical SASP and sustained contractile or metabolic dysfunction are more informative than cell-cycle arrest in terminally differentiated cardiomyocytes; immune-cell senescence should be distinguished from transient activation, exhaustion, apoptosis and pyroptosis by being supported by persistent molecular and secretory alterations together with durable changes in effector function. Figure 2 illustrates the cell type-specific mechanisms connecting AICS with CVD progression.

Figure 2.

Cell type-specific mechanisms linking AICS to CVD progression. Cardiovascular stressors such as shear stress, IRI and inflammation may promote ATP release into the extracellular space. Elevated extracellular ATP can activate cell type- and purinergic receptor subtype-specific responses mediated by P2X7R, P2Y2R and other P2Y receptors. In endothelial cells, ATP-related signaling may induce Ca²⁺ homeostasis disruption, reduce NO bioavailability and upregulate adhesion molecules such as VCAM-1 and ICAM-1, thereby contributing to endothelial dysfunction. In cardiomyocytes, ATP/P2Y receptor signaling may be associated with NOX2/TRPC3-dependent ROS accumulation, mitochondrial dysfunction and Ca²⁺ imbalance, thereby contributing to metabolic stress. These cell type-specific responses converge into an integrated stress hub defined by Ca²⁺ imbalance, ROS accumulation and mitochondrial stress. Under persistent or chronic pathological conditions, these signaling networks may promote senescence-like alterations, including DNA damage, G0/G1 cell-cycle arrest in proliferative cell populations, inflammatory amplification, mtDNA damage, impaired PINK1/Parkin-mediated mitophagy, and increased p21 and p16 expression. The SASP, through factors such as IL-1β, chemokines, MMPs and TGF-β, may amplify inflammatory responses, promote immune cell recruitment and remodel the ECM, thereby contributing to the progression of CVDs such as atherosclerosis, myocardial fibrosis and heart failure. Therefore, these changes should be considered as indicators of pro-senescent or senescence-like states rather than being equated with definitive cellular senescence. In mature cardiomyocytes, persistent DDR, mitochondrial dysfunction, impaired mitochondrial quality control, senescence-associated secretory changes, and sustained contractile or metabolic dysfunction are more informative than cell-cycle arrest. In this schematic, solid arrows denote experimentally supported relationships within individual cited systems, whereas dashed arrows denote proposed or inferred cross-model connections.

Purinergic Receptor-Mediated Endothelial Cell Senescence

Because they are constantly challenged with hemodynamic shear stress, oxidized lipids and inflammatory mediators, endothelial cells are one of the first cell types to become functionally altered in response to cardiovascular injury. IRI and altered perfusion both encourage the release of ATP from endothelial cells, and elevated extracellular ATP targets P2 receptors to affect Ca²⁺ signaling, NO production, and inflammation. Prolonged ATP/P2 receptor activation could lead to a transition from transient functional activation to endothelial dysfunction, thus providing a conducive milieu for the establishment of senescence-associated phenotypes.

In endothelial cells, mechanotransduction of hemodynamic shear stress can stimulate ATP production, leading to ATP release into the extracellular space and initiation of purinergic receptor-mediated Ca²⁺ signaling.⁷ This property allows endothelial cells to act not only as sensors of extracellular ATP levels, but also as mediators of the local purinergic microenvironment in the vascular wall. A critical caveat to keep in mind regarding ATP signaling is its considerable context-dependence. In conditions of acute reperfusion, ATP release from the intracellular space or exogenous administration of ATP protects against impaired barrier function in coronary endothelium.⁵⁸ Thus, ATP effects on endothelial cells should not be regarded as a bare damaging process, and instead need to be understood within the limits of stimulus intensity, exposure time and pathological context. Sustained elevation or excess amplification of extracellular ATP under pathological conditions related to cardiovascular injury is, instead, more prone to favor chronic endothelial activation and imbalance between function and dysfunction through P2 receptor-mediated signaling pathways compared with transient adaptive ATP signaling.

In addition, with chronic pathological extracellular ATP accumulation, P2 receptors are able to transform nucleotide stimulation into the induction of inflammatory environments in endothelial cells that enhance adhesive phenotypes and cause a loss of vascular tone regulation capacity. The P2X7R delivers ATP signals to the p38 MAPK, subsequently enhancing E-selectin expression and IL-8 secretion. P2X7R deficiency markedly lowers E-selectin expression in mouse aorta overlying atherogenesis landscapes, revealing that P2X7R serves as a functional mediator of mechanical stress–purinergic signaling vis-a-vis endothelial inflammatory activation.¹⁵ In line with this, other studies also show that P2X7R deficiency reduces the proportion of pro-inflammatory Ly6C^high monocytes, increases the proportion of anti-inflammatory Ly6C^low monocytes, and decreases endothelial VCAM-1 expression, indicating that P2X7R serves as a regulator in vascular inflammatory microenvironments and endothelial adhesion activation.⁵⁹ In addition to P2X7R, exploratory studies showed that shear stress-induced ATP release stimulates endothelial P2Y2 receptors. Using mice deficient in the P2Y2 receptor specifically in endothelial cells (inducible endothelium-specific P2Y2-deficient mice), Wang et al demonstrated that the loss of P2Y2 impaired flow-mediated vasodilation, reduced eNOS activation and elevated arterial blood pressure.⁸ These findings suggest that endothelial P2Y2 signaling is physiologically required for flow-dependent eNOS/NO activation and vascular tone regulation in normal states, but does not provide direct evidence of cellular senescence. Collectively, these findings suggest that purinergic receptors such as P2X7R and P2Y2R can remodel endothelial functional states through p38 MAPK signaling, adhesion molecule regulation, inflammatory mediator production, and the eNOS/NO pathway, thereby providing an important upstream signaling context for the development of senescence-associated endothelial phenotypes during chronic vascular injury.

Instead of just being a state of reduced cellular function, endothelial senescence is a pathological condition characterized by the simultaneous occurrence of cell-cycle arrest, pro-inflammatory phenotypes, DDR and SASP, together with loss of regenerative ability. Telomere dysfunction can lead to endothelial cell senescence inducing vascular and metabolic dysfunction.⁶⁰ In human aortic endothelial cells (HAEC), telomere dysfunction-induced senescence is associated with upregulation of ICAM-1 and reduced eNOS activity,⁶¹ showing significant phenotypic overlap with P2 receptor-mediated adhesion molecule upregulation and decreased NO bioavailability. Senescent endothelial cells similarly can have a persistent G0/G1 cell-cycle arrest state, with inflammatory activation, accumulation of DNA damage, aberrations in cell-cycle control and decreased angiogenic and regenerative activity.⁶² So, disturbance of Ca²⁺ homeostasis via ATP/P2 receptor signaling activation, inflammatory endothelial adhesion molecule expression, and robust eNOS/NO signaling component downregulation should not be considered as a direct entry to the senescence program. Rather, these adaptations might indicate significant pathological situations that may readily evoke or amplify endothelial senescence.

Thus, ATP/P2 receptor signaling may create a conducive milieu for endothelial senescence-associated changes by enhancing the activation of endothelial inflammation, expression of adhesion molecules and a decrease in NO signaling. However, these changes are not equivalent to cellular senescence and should be assessed alongside canonical hallmarks of senescence such as a persistent DDR, cell-cycle arrest, SASP formation, and compromised regenerative ability. Among the different cell populations considered within the hypothesis of AICS in CVDs, endothelial cells may be among those that should be prioritized in future research.

Oxidative Stress- and Mitochondrial Dysfunction-Driven Cardiomyocyte Senescence

Continuous contractile activity in cardiomyocytes relies on a constant supply of ATP, proper Ca²⁺ handling, and mitochondrial homeostasis. Cardiac mitochondria occupy approximately one-third of cellular volume, generate over 95% of cardiac ATP,⁶³ and play important roles in redox homeostasis, Ca²⁺ handling, and lipid metabolism. Consequently, disturbances affecting ATP production, Ca²⁺ handling, or redox balance can impair mitochondrial metabolism and reducing-equivalent regeneration. In heart failure, elevated cytosolic Na⁺ could facilitate mitochondrial Na⁺/Ca²⁺ exchanger-induced Ca²⁺ efflux, thereby lowering mitochondrial Ca²⁺ and Ca²⁺-dependent tricarboxylic acid cycle activity, limiting NADPH regeneration while augmenting ROS accumulation.⁶⁴ Such disturbances may lead to a microenvironment where mitochondrial dysfunction, ROS overproduction, and DNA damage trigger senescence-associated cardiomyocyte phenotypes.^63–65 Altered ATP signaling may transmit local stress stimuli through P2 receptor activation and redox effects in this metabolic background. ATP-mediated P2Y receptor stimulation induces atrophy in neonatal rat cardiomyocytes through a non-cell-death mechanism, accompanied by increased Nox2 expression and enhanced Nox2–TRPC3 interaction, inducing excess ROS generation.⁶⁶ Although there is no direct correlation between cardiomyocyte atrophy and cellular senescence, these results nonetheless reveal a ROS-dependent extracellular ATP–P2Y–Nox2/TRPC3 stress axis linked to phenotypic alterations in cardiomyocytes. At the same time, IRI could also generate a ROS burst due to sudden re-oxygenation and chronic ETC stress, leading to oxidative modification of many macromolecules, including mitochondrial DNA (mtDNA).⁶⁵

Mature cardiomyocytes are terminally differentiated cells, and for this reason it is not sufficient to merely interpret their senescence-associated phenotypes through the traditional model of replicative senescence seen in proliferative cells. Rather than being a definitive cellular fate, cardiomyocyte senescence is conceptualized as an ongoing process of functional decline consequent to sustained DNA damage, mitochondrial quality control dysfunction and the development of so-called SASP. In cardiomyocytes, telomere dysfunction in the absence of telomere shortening leads to activation of the p21 and p16 signaling pathways and elicits a non-canonical SASP with pro-fibrotic and pro-hypertrophic features.¹⁴ Impaired mitophagy also contributes to this accumulation of damaged mitochondria. Mitochondrial autophagy through PINK1 or Parkin is involved in cardiomyocyte senescence induced by advanced glycation end products, whereas impairment of p62/Parkin-associated mitophagy reduces the ability of cardiomyocytes to respond to stress-induced injury.^13,67 Moreover, a further consequence of these processes can include dysregulated protein quality control that occurs in cellular senescence and mTORC1 activation, whereby proteostatic stress is exacerbated by heart failure with preserved ejection fraction (HFpEF), generating a self-energizing pathological feedback loop driven by mitochondrial damage, impaired protein homeostasis and progressive cardiac dysfunction.⁶⁸ Together, ATP-associated ROS generation and mitochondrial dysfunction might synergistically foster the acquisition of senescence-associated cardiomyocyte phenotypes by amplifying telomere damage responses, compromising mitochondrial autophagy and establishing a non-canonical SASP. These changes are marked by an impaired energetic reserve, reduced contractile efficiency and metabolic plasticity with more pronounced pro-fibrotic and pro-hypertrophic signals that potentiate post-MI remodeling and the progression of heart failure.

Consequently, mitochondrial damage, ROS accumulation, aberrant Ca²⁺ handling, atrophy and hypertrophy should be viewed as attributes of stress rather than definitive signs of cardiomyocyte senescence. Future studies should longitudinally define cardiomyocyte senescence by evidencing persistent DDR-p21/p16 activation, impaired mitochondrial quality control, non-canonical SASP and sustained contractile or metabolic dysfunction to the exclusion of apoptosis and other acute injury responses.

SASP-Mediated Inflammatory Amplification and Cardiovascular Microenvironment Remodeling

Cardiovascular remodeling is often associated with chronic inflammatory reactions. Cardiomyocyte injury, endothelial activation, immune cell infiltration and fibroblast activation can communicate bidirectionally to keep the local tissue environment in a self-perpetuating pro-inflammatory/pro-fibrotic state. In this respect, SASP represents a significant link between cellular senescence and pathology at the tissue level. Inflammatory cytokines and chemokines and other ECM remodeling molecules secreted by senescent cells propagate the effects of localized cellular stress responses into coordinated multicellular remodeling processes.^5,6,69,70

Myocardial necrosis after MI recruits inflammatory cells, promotes cytokine release and activates fibroblast-to-myofibroblast transition with induction of ECM deposition leading to scar formation. Scar tissue, in contrast, is non-contractile and increases the hemodynamic burden on surviving cardiomyocytes leading to manifestations such as adverse ventricular remodeling with chamber dilation, myocardial hypertrophy and progression to heart failure.⁷¹ In this multicellular network, the pathological nature of SASP is not determined by the levels of individual secreted factors but instead by the persistent interaction of senescent cells with surrounding cells, immune cell trafficking and local ECM composition. These mechanisms demonstrate how individual cellular senescence events can be communicated more broadly from cell-to-cell and propagated to tissue-level remodeling of the cardiovascular microenvironment.

The SASP produced by senescent VSMCs can directly modulate immune cell recruitment, ECM stability and neighboring cells’ inflammatory status within the vascular wall itself. Senescent human VSMCs secrete a diverse array of cytokines and chemokines and induce in vitro and in vivo monocyte chemotaxis. Additionally, they produce more active MMP-9 and less collagen, show upregulation of inflammasome components, and induce pro-adhesive and pro-inflammatory phenotypes in neighboring endothelial cells and VSMCs.⁵ These results go beyond supporting SASP as a simple cellular senescence marker to show that it actively remodels the vascular wall microenvironment. Macrophages with foamy morphology expressing senescence markers may consistently accumulate in the subendothelial space during early atherosclerosis and exert proatherogenic effects by promoting the expression of atherogenic inflammatory cytokines/chemokines. In more advanced plaques, senescent cells are thought to stimulate metalloproteinase production and elastin degradation, which results in weak fibrous cap features indicative of plaque instability.⁵³ In addition, SASP can drive local senescence signal spreading via an IL-1-linked inflammatory axis and paracrine propagation of senescence, inducing a persistent inflammatory niche in the vascular wall.⁵⁷

SASP-mediated microenvironmental remodeling extends beyond just vascular inflammation, encompassing fibroblast activation, ECM regulation and fibrotic remodeling. Thus, TGF-β-related factors are among the key SASP factors with potential tissue-remodeling ability, while TGF-β/Smad signaling in cardiac fibroblasts itself emerges as a central regulatory axis that controls injury-induced fibrosis and matrix remodeling. Deletion of Smad2/3 in tissue-resident fibroblasts decreases injury-induced fibroblast proliferation and expression of fibrosis-related genes. Likewise, deletion of both Smad2/3 and Tgfbr1/2 in cardiac fibroblasts reduces the expression of genes related to fibrotic responses and ECM remodeling.⁷² While these fibroblast-specific findings do not demonstrate that TGF-β derived from SASP is necessarily sufficient to drive cardiac fibrosis, they also bolster the idea that SASP-associated remodeling factors can affect fibroblast responses and contribute to remodeling of the ECM. At the same time, ATP/P2X7R signaling in neutrophils can cause potassium efflux, NLRP3 inflammasome activation and IL-1β secretion.¹² While this acute inflammatory response is distinct from both cellular senescence and the SASP, it could theoretically act as an upstream amplifier of the SASP-mediated inflammatory microenvironment, thereby sustaining interactions among senescent cells, innate immune cells, and stromal cells.

The initiation of cellular senescence and subsequent release of SASP is a key mechanism by which cellular senescence alters the cardiovascular microenvironment. Inflammatory signaling pathways driven by ATP and associated metabolites may enhance infiltration of immune cells, degradation of the ECM, and fibrotic remodeling by promoting IL-1β production, chemokine release, MMP activation, and TGF-β-related responses. Nevertheless, the effect of ATP/P2 receptor signaling on SASP formation is not completely understood, and generalizations attributing all inflammatory remodeling solely to AICS should be avoided.

AICS in Common CVDs

However, in CVDs, ATP/purinergic signaling does not work alone through a specific cell type but collaborates with several other pathological stimuli such as lipid overload, pressure overload, IRI, metabolic derangement and chronic inflammation. Collectively, these observations suggest that ATP/purinergic signaling may contribute to a pathological milieu that favors senescence-associated remodeling in macrophages, endothelial cells, VSMCs, cardiomyocytes and progenitor cells, thereby contributing to atherosclerotic progression, vascular remodeling, myocardial fibrosis and cardiac dysfunction, as further outlined in Table 2.

Table 2.

Mechanistic Associations Between AICS and CVDs

CVDs/Pathological Conditions	Affected Cell Types	ATP–Purinergic Signaling Alterations	Cellular Senescence-Related Mechanisms	Key Pathological Effects	Roles in Disease Progression	References
Atherosclerosis	Plaque macrophages;25 hematopoietic cells and macrophages73	ATP–P2X7R–caspase-1/IL-1β inflammasome signaling25	p16INK4a/p21 upregulation, SA-β-gal activity, SASP, oxidative stress, and impaired macrophage efferocytosis73	Plaque inflammation and reduced atherosclerotic lesion burden after P2X7R deficiency;25 defective inflammation resolution and increased plaque necrosis associated with senescent hematopoietic/macrophage cells73	Inferred link: ATP/P2X7R-dependent inflammasome activation promotes plaque inflammation and atherosclerosis,25 whereas senescent hematopoietic/macrophage cells impair efferocytosis and inflammation resolution, thereby promoting plaque necrosis and atheroprogression.73	[25,73]
Atherosclerosis	Plaque macrophages;25 THP-1 macrophages and macrophage-derived foam cells29	ATP–P2X7R–caspase-1/IL-1β inflammasome signaling25	p16INK4a-associated macrophage senescence, increased SA-β-gal activity and SASP, increased CD36/LOX-1 expression, and reduced cholesterol efflux29	Plaque inflammation and atherosclerotic lesion formation;25 enhanced macrophage foam-cell formation and lipid accumulation29	Inferred link: ATP/P2X7R-dependent inflammasome activation promotes plaque inflammation and atherosclerosis,25 whereas p16INK4a-associated macrophage senescence enhances foam-cell formation through increased CD36/LOX-1 expression and reduced cholesterol efflux.29	[25,29]
Vascular barrier dysfunction	Vascular endothelial cells;74 replicatively senescent HUVECs75	Extracellular ATP–P2Y2R-mediated Akt inhibition and perlecan suppression74	SA-β-gal activity, γH2AX, p21 upregulation, loss of proliferative capacity, and disruption of adherens and tight junctions75	Reduced endothelial perlecan expression;74 disrupted VE-cadherin/ZO-1 organization, reduced occludin/claudin-5 expression, and increased endothelial permeability75	Inferred link: extracellular ATP/P2Y2R signaling suppresses endothelial perlecan expression through Akt inhibition,74 whereas endothelial senescence disrupts intercellular junctions and increases endothelial permeability,75 providing complementary mechanisms for vascular barrier dysfunction.	[74,75]
Ang II–induced hypertensive cardiovascular remodeling	Cardiomyocytes;23 vascular smooth muscle cells (VSMCs)76	Ang II–P2X7R–HuR–GPX4/HO-1 signaling in cardiomyocytes23	SA-β-gal activity, p-H2AX, p21, p16, CD38-dependent NAD depletion, and senescence-associated small extracellular vesicle (SA-sEV) signaling in VSMCs76	Cardiomyocyte ferroptosis, cardiac hypertrophy, fibrosis, and dysfunction;23 VSMC senescence, hypertension, and vascular remodeling76	Inferred link: Ang II/P2X7R signaling promotes cardiomyocyte ferroptosis and cardiac remodeling through HuR-dependent regulation of GPX4 and HO-1 mRNA stability,23 whereas CD38-dependent NAD depletion promotes VSMC senescence and SA-sEV-mediated propagation of senescence, exacerbating hypertensive vascular remodeling.76	[23,76]
Atherosclerosis	Plaque macrophages and vascular wall cells;77 senescent VSMCs and other vascular cells78	P2Y6R upregulation in atherosclerotic lesions and UDP–P2Y6R-mediated macrophage activation77	Accumulation of senescent vascular cells, particularly VSMCs, with senescence-associated transcriptional programs involving ECM organization and collagen remodeling78	Macrophage inflammatory activation and atherosclerotic plaque formation;77 senescence-associated ECM remodeling, altered plaque structure, and vascular dysfunction78	Inferred link: UDP/P2Y6R signaling promotes macrophage inflammatory activation in atherosclerosis,77 whereas senescent vascular cells, particularly VSMCs, exhibit ECM-remodeling programs that contribute to plaque structural remodeling and vascular dysfunction.78	[77,78]
Age-associated atherosclerosis	VSMCs, endothelial cells, and vascular leukocytes;79 senescent VSMCs80	CD73-mediated AMP-to-adenosine metabolism79	Persistent DNA/telomere damage, SA-β-gal activity, p16 upregulation, and senescence-associated VSMC de-differentiation/fibromyocyte transition80	Age-dependent plaque accumulation associated with CD73-dependent adenosine production;79 increased atherosclerotic burden and loss of the contractile VSMC phenotype80	Inferred link: CD73-dependent AMP-to-adenosine metabolism promotes age-dependent atherosclerotic plaque accumulation,79 whereas VSMC senescence promotes a de-differentiated/fibromyocyte phenotype and impairs re-differentiation to a contractile state, contributing to atherosclerotic remodeling.80	[79,80]
Post-stroke atherosclerosis	Vascular endothelial cells81,82	TNF-α–TNFR1/Src–Panx1-mediated endothelial ATP release81	Persistent endothelial senescence driven by sustained Notch1 signaling after stroke82	ATP-dependent VCAM1 upregulation and leukocyte adhesion/emigration;81 persistent VCAM1 expression, myeloid cell adhesion, and accelerated systemic atheroprogression after stroke82	Inferred link: Panx1-mediated endothelial ATP release promotes VCAM1-dependent leukocyte adhesion during vascular inflammation,81 whereas sustained Notch1 signaling after stroke induces a senescent, pro-inflammatory endothelial phenotype that enhances VCAM1 expression, myeloid cell adhesion, and systemic atheroprogression.82	[81,82]
Myocardial ischemia/reperfusion injury	Cardiomyocytes and interstitial cells;6 monocytes/macrophages and cardiomyocytes83	P2X7R upregulation and P2X7R–NLRP3/caspase-1/IL-1β signaling, accompanied by increased CD39 expression in diabetic MI/R injury83	IRI-induced cellular senescence in cardiomyocytes and interstitial cells with a pro-inflammatory, profibrotic, and anti-angiogenic SASP6	Adverse remodeling, impaired myocardial vascularization, scar formation, and cardiac dysfunction;6 increased inflammation, apoptosis, infarct size, and impaired cardiac function83	Inferred link: IRI-induced cellular senescence and SASP contribute to adverse cardiac remodeling and impaired functional recovery,6 whereas P2X7R signaling amplifies NLRP3-dependent inflammation and apoptosis during diabetic MI/R injury.83	[6,83]
Isoproterenol (ISO)-induced cardiomyopathy/pathological cardiac hypertrophy	Human cardiac myofibroblasts and cardiac tissue;84 cardiomyocytes85	ATP/BzATP–P2X7R–NLRP3 inflammasome signaling in cardiac myofibroblasts84	Increased SA-β-gal activity, lipofuscin accumulation, p16, p19, p21, p53, GATA4, and SASP-related IL-6/TNF-α expression in cardiomyocytes85	NLRP3-associated inflammation, cardiomyocyte hypertrophy, myofibroblast accumulation, and cardiac fibrosis;84 pathological cardiomyocyte hypertrophy with a senescence-associated phenotype85	Inferred link: ATP/BzATP–P2X7R signaling promotes cardiac myofibroblast NLRP3 inflammasome activity and contributes to inflammatory and fibrotic remodeling in ISO-induced cardiomyopathy,84 whereas ISO induces a senescence-associated phenotype in cardiomyocytes during pathological cardiac hypertrophy.85	[84,85]

Atherosclerosis

Atherosclerosis represents a chronic vascular wall disease and is characterized by the combination of lipid stress, endothelial activation, infiltration of immune cells and remodeling of VSMCs. After the deposition of oxidized lipoproteins in the subendothelial area, endothelial cells and VSMCs secrete attractive signals for circulating monocyte recruitment, as well as signals inducing a foam-cell macrophage phenotype. Additional chronic pro-inflammatory signaling promotes the recruitment of immune cell types including T and B lymphocytes, dendritic cells, and mast cells to atherosclerotic lesions, advancing development from early fatty streaks to advanced plaques.⁵³ In the inflammatory microenvironment, endothelial senescence may further potentiate inflammatory responses through epigenetic reprogramming and hypersensitivity to VCAM-1-mediated adhesion, both of which lead to monocyte adhesion and lesion progression.⁸⁶ Integrated effects of lipid accumulation, impaired shear stress and endothelial senescence form a pathological basis for extracellular ATP/P2 receptor signaling to exacerbate plaque inflammation.

Based on the local milieu of oxLDL stimulation, endothelial injury, and disturbed blood flow within atherosclerotic lesions, extracellular ATP/P2 receptor signaling is hypothesized to function as a local inflammatory amplification node. Monocyte–endothelial cell adhesion initiated by oxLDL is mediated through P2Y2 receptor activation, which acts through ROS-dependent expression of endothelial adhesion molecules. Furthermore, evidence that extracellular ATP activates P2Y2 receptors to induce vascular inflammation and promote atherosclerosis further supports the proposal that the extracellular ATP/P2Y2R axis represents an important link connecting ATP signaling with inflammatory cascades in atherosclerotic plaques.^36,87 In addition, ATP-associated P2Y signaling can drive oxLDL-mediated inflammasome stimulation and IL-1β production through pathways linked with the mitochondrial reactive oxygen species–mtDNA (mtROS–mtDNA) axis and the TLR9–NF-κB signaling pathway.¹⁶ P2X7R can transduce ATP signals into endothelial inflammatory responses associated with p38 MAPK in areas where flow is disturbed and that are atherosclerosis-prone, bringing support to the idea that purinergic signaling may connect local mechanical stress with endothelial activation.¹⁵ These data primarily support ATP/P2 receptor-dependent inflammatory activation and adhesion rather than direct induction of cellular senescence. Persistent ROS, IL-1β, NF-κB signaling, and adhesion responses may nevertheless create a proinflammatory and prooxidative milieu that is permissive for plaque cell senescence and subsequent SASP-associated remodeling.

The accumulation of senescent cells, under conditions in which lipid deposition, inflammatory activation, and oxidative stress exist simultaneously within atheroma plaques, may enhance local inflammatory responses as well as promote structural instability. In early foam cell-type macrophages and in advanced atherosclerotic lesions, senescent cells can contribute to disease progression, such as degradation of elastin and thinning or rupture of the fibrous cap by secretion of inflammatory cytokines, chemokines, and MMPs.⁵³ VSMCs are also capable of acquiring a senescence-associated phenotype within plaques, including replicative senescence, persistent DNA damage and features characteristic of premature senescence. These changes could correlate with TRF2 dysfunction and chronic telomeric DNA damage, together with the development of micronuclei, cGAS–STING activation, and increased expression of proinflammatory factors.⁸⁸ The accumulation of senescent cells leads to increased expression of SASP components and MMPs, downregulation of collagen synthesis, and secretion of inflammatory mediators, which together affect fibrous cap stability, with plaque rupture being a fundamental pathological event in MI and stroke.⁸⁹

ATP/P2 receptor signaling may therefore favor plaque-cell senescence and SASP persistence by sustaining endothelial inflammation, monocyte recruitment, and oxidative stress. Whether ATP signaling itself initiates or maintains a stable senescent phenotype within atherosclerotic plaques remains unresolved.

Hypertension

The role of ATP signaling in hypertension is context-dependent. Controlled endothelial ATP/P2Y2 signaling participates in flow-mediated NO production and vasodilation, but continuous high levels of extracellular ATP may aggravate vascular injury by activating P2X7R-associated immune inflammatory responses. Hypertension is a critical disease context in terms of assessing the AICS hypothesis due to the duality between physiological vascular regulation and pathological inflammatory amplification.^8,90–92

In conditions of hypertension, although vascular smooth muscle cell stiffness and adhesiveness are increased, these changes become more pronounced with age.⁹³ In spontaneously hypertensive rats, increased vascular smooth muscle cell stiffness might be due to persistent blood pressure overload or may represent greater intrinsic rigidity of the vascular wall.⁹⁴ Mechanical stress and consequent vascular stiffening amplify one another, leading to a vicious cycle in which the vascular aging-like features that hypertension imposes—partial inhibition of vascular compliance, impaired vasomotor reserve, and increased sensitivity toward chronic inflammatory stimulation—create reciprocal reinforcement. In this setting, ATP/P2 receptor signaling is not only important in the regulation of vascular tone but may also play a role in long-term modulation of endothelial NO homeostasis and inflammation when blood vessels are mechanically overloaded and begin to stiffen.

Hemodynamic mechanical stimulation enhances vascular function in an ATP-mediated manner that is required for endothelium-dependent vasodilation. In endothelial cells, the mechanosensitive cation channel PIEZO1 mediates fluid flow-induced ATP release and activation of downstream P2Y2/Gq/G11 signaling leading to AKT/eNOS phosphorylation, NO production, and vasodilation. PIEZO1-deficiency specifically in endothelial cells results in reduced flow-dependent NO production and vasodilation, and the development of hypertension.⁹⁰ The current findings demonstrate that a tightly regulated ATP–P2Y2–eNOS/NO axis maintains vascular relaxation homeostasis at physiological levels. In hypertension, the key question could be whether this mechanotransduction–purinergic vasodilatory pathway is impaired by chronic pressure overload and endothelial injury in a way that attenuates NO-dependent vasodilatory reserve.

Unlike the endothelial vasodilatory pathway, persistently high extracellular ATP in hypertension has been clearly linked with immune inflammatory amplification. Extracellular ATP levels are elevated in hypertensive mice and patients, where ATP activates P2X7R signaling resulting in IL-1β production and T cell activation and the development of memory T cells. Furthermore, a UK Biobank genetic analysis identified three P2RX7 single-nucleotide polymorphisms associated with increased odds of elevated diastolic blood pressure; deletion or pharmacological antagonism of P2RX7 inhibited angiotensin II–induced hypertension, vascular injury, and immune cell activation.⁹¹ Moreover, P2X7R on CD8⁺ T cells may induce an antigen-independent T cell response in salt-sensitive hypertension.⁹² These results broaden the role of extracellular ATP from a signaling vascular regulatory molecule to an important modulator of immune inflammatory responses. While T cell activation and IL-1β release at the vascular niche cannot be directly linked to P2X7R-mediated cellular senescence, chronic immune inflammation, oxidative stress and cytokines may culminate in a pathogenic microenvironment supporting endothelial senescence, vascular wall stiffening and persistence of hypertension.

Importantly, endothelial senescence and disruption of NO/eNOS homeostasis may represent important downstream mechanisms linking abnormal ATP/P2 receptor signaling with sustained hypertension. In addition, replicative senescence attenuates endothelial eNOS expression and NO bioavailability while promoting monocyte adhesion. In contrast, stable expression of hTERT maintains a more youthful endothelial phenotype and sustains higher eNOS protein expression and NO activity.⁹⁵ Removal of senescent cells restores NO bioavailability, while decreasing oxidative stress and increasing NO-mediated endothelium-dependent vasodilation; some benefits also correlate with changes in circulating SASP factors.⁹⁶ Oxidation of tetrahydrobiopterin (BH4) at the level of redox regulation can result in eNOS uncoupling, restricting NO production while increasing free radical generation and leading to senescence-associated endothelial inflammatory responses.⁹⁷ In addition, interventions directed at senescent cells can reverse age-associated eNOS uncoupling to reduce ROS production and mitochondrial dysfunction as well as enhance NO bioavailability.⁹⁸

The differential role of ATP signaling in hypertension is as follows: a controlled ATP/P2Y2/eNOS pathway supports vascular relaxation, while sustained extracellular ATP/P2X7R activation may promote immune inflammation and endothelial injury. Evidence for the relationship between AICS and hypertension is currently mostly indirect. In future investigations, these findings should be critical for establishing the causal relationships between abnormalities in ATP/P2 signaling and endothelial senescence, arterial stiffness, and chronic vasculature-intrinsic inflammatory responses.

Coronary Heart Disease

In coronary heart disease, ATP/P2 receptor signaling serves predominantly as a key modulator of local plaque inflammation and prothrombotic responses. Accumulation of oxidized lipids, disturbed blood flow and endothelial injury within coronary lesions may enhance local purinergic signaling in a favorable milieu for monocyte adhesion and endothelial inflammatory activation associated with enhanced tissue factor-associated procoagulant responses. In this way, ATP/P2 receptor signaling may participate in the shift of coronary plaques from a more stable state towards a vulnerable phenotype by these mechanisms.^15,99 At the clinical level, circulating galectin-3 is elevated in both acute and chronic coronary syndromes and may reflect the inflammatory burden of coronary atherosclerosis, although its ability to distinguish between these disease stages is limited.¹⁰⁰

Plaque rupture and ulcer-like lesions detected using optical coherence tomography (OCT), which are frequently seen in acute coronary syndrome, are both manifestations of coronary plaque instability. The latter is seen more often in patients with non-ST-elevation acute coronary syndrome and younger subjects.¹⁰¹ In addition to plaque rupture and erosion, myocardial ischemic events might also arise as a consequence of other mechanisms including epicardial coronary artery spasm, microvascular spasm or coronary embolism, and spontaneous coronary artery dissection (SCAD) in clinical scenarios such as MI with non-obstructive coronary arteries (MINOCA).¹⁰² Both the severity of coronary stenosis and the burden of high-risk plaques are associated with increased risk of clinical cardiovascular events.¹⁰³ Therefore, coronary heart disease can be considered an ischemic syndrome driven by the combined effects of structural coronary lesions, abnormal endothelial reactivity, and a locally prothrombotic microenvironment.

In coronary lesions where necrotic cores and inflamed/oxidized lipids coexist with stenosis and disturbed blood flow, ATP/P2 receptor signaling may transduce mechanical stress to induce persistent inflammation in endothelial cells. Shear stress is relevant to ATP production by mitochondria in endothelial cells, with a potential metabolic basis for increased local purinergic signaling.¹⁰⁴ Studies show that P2X7R activity is regulated by shear stress in regions exposed to disturbed flow and that this promotes p38 MAPK-associated endothelial inflammatory responses in atherosclerosis-prone sites.¹⁵ OxLDL, in concert with ATP/UTP, can also induce monocyte–endothelial cell adhesion via P2Y2 receptor-mediated upregulation of ICAM-1 and VCAM-1 expression—another cellular mechanism fundamentally linked to the ROS-dependent regulation of adhesion molecule expression.⁸⁷ These findings suggest that ATP/P2 receptor signaling in coronary lesions may create a local amplification loop connecting mechanical stress, oxidized lipids and endothelial inflammation. Although direct induction of cellular senescence is not supported by current evidence, pro-inflammatory and pro-adhesive effects are supported, and persistent generation of ROS, Ca²⁺ dysregulation, and inflammatory and adhesion responses may provide long-term stress conditions for coronary endothelial senescence in chronically stressed microenvironments that facilitate the progression of vascular aging.

Coronary ischemic events also depend on local thrombus formation and microvessel dysfunction. Macrophages and VSMCs release tissue factor–carrying prothrombotic microparticles, and ATP/P2X7R signaling plays a role in inducing tissue factor procoagulant activity. P2Y2 receptor signaling can, in turn, regulate endothelial tissue factor expression linking purinergic signaling with vascular inflammation and thrombus formation.^99,105 Apart from structural coronary obstruction, significant coronary functional abnormalities also exist in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) without angiographically obstructive coronary artery disease; thus, it is possible that impaired coronary endothelial reactivity and local microvascular perfusion disturbances may independently affect myocardial ischemia in this setting.¹⁰⁶

Consequently, the role of ATP/P2 receptor signaling in coronary heart disease is predominantly characterized by the enhancement of plaque inflammation, endothelial dysfunction and prothrombotic conditions. Taken together, the existing relationship between ATP/P2 receptor signaling and cellular senescence is largely circumstantial, since one cannot directly deduce that signaling by ATP leads to senescence of coronary vascular cells.

MI

MI is a clinically critical end-event of coronary heart disease resulting from ischemic myocardial necrosis due to acute coronary artery occlusion or significant hypoperfusion. Acute ATP release, ROS generation and sterile inflammation can be rapidly elicited by ischemic injury with necrosis and reperfusion stress to create a highly inflammatory damage signaling milieu in the infarcted zone. In MI, this early ATP response is temporally distinct from the senescence-associated changes that emerge during subsequent repair and remodeling phases.^6,107

After acute myocardial infarction (AMI), ischemic necrosis and reperfusion stress can concurrently injure cardiomyocytes, endothelial cells, fibroblasts and the interstitial matrix, rapidly initiating sterile inflammatory responses through complement activation, ROS production, DAMP release and activation of pattern-recognition receptors. Of these pathways, Toll-like receptors (TLRs) and NLRP3 inflammasome-related signaling form principal components involved in inflammatory amplification in infarcted myocardium.¹⁰⁸ In inflammation, endothelial cell activation can enhance ATP release through Panx1 channels under ischemia–reperfusion conditions, leading to the potentiation of local inflammatory responses.¹⁰⁷ Therefore, elevated extracellular ATP after MI should be interpreted primarily as a component of acute injury signaling and inflammatory activation rather than being directly equated with cellular senescence itself.

ATP/P2 receptor signaling in the acute ischemia–reperfusion phase is primarily an amplifier of inflammatory injury and not direct evidence supporting the induction of senescence. Activated P2X7R signaling is linked to larger infarction sizes, decreased ventricular contractile function, and increased cardiomyocyte apoptosis as well as immune cell infiltration in animal models of myocardial ischemia-reperfusion (MI/R). Its upregulation is primarily associated with monocyte and macrophage recruitment.⁸³ These results are consistent with the concept of the P2X7R axis linking post-infarction immune inflammatory responses, but P2X7R-mediated inflammation, apoptosis or tissue injury should not be the definition of cellular senescence. In line with the later disease development, IRI enables senescence-associated phenotypes in cardiomyocytes and interstitial cell populations. In addition, navitoclax administration after IRI improves left ventricular function and myocardial vascularization and reduces fibrosis.⁶ These results show that senescent cell burden participates in functional recovery and scar remodeling after IRI, but do not prove a complete dependence of senescence on upstream ATP/P2X7R signaling. A more cautious interpretation may be that the ATP/P2X7R signaling–mediated acute inflammatory microenvironment is permissive for future or continued emergence of senescence-associated maladaptive states, but such cause and effect will need additional assessment approaches tailored by cell type.

The prominent pathophysiological role of senescence following AMI may be when the repair and remodeling stages are underway. DDR-related pathways play important roles in the precise regulation of early fibroblast proliferation, collagen synthesis, and scar formation after infarction. Because loss of Atm increases early post-MI fibroblast proliferation and aggravates cardiac fibrosis, this finding points to impaired DNA damage repair as a potential modifier of fibrotic remodeling following myocardial injury.¹⁰⁹ In post-infarction hearts and hypoxia/reoxygenation-treated cardiac fibroblasts, elevated p53 expression-related senescence and cytokine production in fibroblasts were accompanied by decreased collagen synthesis. In contrast, inhibition of p53 reduced hypoxia/reoxygenation-induced fibroblast senescence and cytokine expression but enhanced collagen production, suggesting that p53-dependent fibroblast senescence differentially regulates inflammatory signaling and matrix deposition after MI.⁶⁹ Immune cells can also play a role in networks of senescence-associated inflammatory remodeling. At the molecular level, transcriptomic analyses showed that senescent macrophages upregulate a pro-inflammatory SASP profile regulated in part by NF-κB and have significantly greater expression of genes related to inflammatory responses and TNF-α signaling, raising the intriguing possibility that these cells may support tissue remodeling after cardiovascular injury by sustaining local inflammation.⁷⁰ Together, these findings extend the concept of post-MI senescence burden beyond cardiomyocytes alone to include fibroblasts, immune cells, and other interstitial cell populations, highlighting its potential influence on scar quality, fibrosis severity, and left ventricular structural remodeling.

ATP release after MI probably acts more directly at this point by participating early on in acute inflammatory responses and immune cell recruitment. Ongoing inflammation, as well as ROS accumulation and DNA damage during the progression of the disease, may further stimulate senescence-associated changes in surviving cardiomyocytes, fibroblasts or immune cells. This process might affect scar maturation, collagen deposition, vascularization recovery and the remodeling of the left ventricle. Yet, existing data do not provide evidence that ATP/P2X7R signaling is the only or major upstream mechanism regulating cellular senescence after MI.

Heart Failure

Heart failure, as a final common pathway of heterogeneous cardiovascular insults, is frequently associated with disturbed energy homeostasis, persistent inflammation, fibroblast activation and interstitial fibrosis. Myocardial contraction, relaxation, and ionic homeostasis are extremely dependent on ATP availability, while either mitochondrial dysfunction or dysregulated ATP metabolism is common during the progression to heart failure.

Recent studies suggest that AICD may contribute to heart failure triggered by MI, IRI, and chemotherapy-related cardiac injury through mechanisms involving energy depletion, metabolic imbalance, disruption of redox homeostasis, and Ca²⁺ dysregulation.¹¹⁰ These results suggest that aberrant ATP metabolism not only mirrors deranged myocardial energy stores but may also be mechanistically involved in heart failure progression via cell death, inflammatory amplification and structural remodeling. But cell death does not mean cellular senescence per se, and it should be discussed as indirect evidence that an ATP-associated injury microenvironment can induce a possible senescent phenotype. The inflammatory milieu generated by ischemic injury, metabolic disturbances, and comorbidity can favor recruitment of both innate immune cells and adaptive immune cells into the myocardium. The reason for this is that these immune populations generally undergo metabolic reprogramming incorporating oxidative phosphorylation (OXPHOS) and anaerobic glycolysis, keeping a long-term environment of local immune activation without resolution.¹¹¹ In contrast, the pathological remodeling observed in heart failure is not restricted to the adaptation of cardiac muscle cells—activation of fibroblasts and programs that remodel multiple cell types work in concert via mechanisms leading to interstitial expansion, ECM deposition and loss of myocardial compliance.¹¹² Sustained action of cardiac contraction, relaxation and ionic homeostasis is highly dependent on ATP supply while the majority of ATP production in cardiomyocytes is provided by mitochondrial OXPHOS.¹¹³ These ATP-related abnormalities primarily reflect intracellular energetic dysfunction and should not be interpreted as evidence of extracellular purinergic signaling.

By contrast, the purinergic component relevant to the AICS hypothesis begins with ATP release into the extracellular space. In ventricular cardiomyocytes, shear stress can promote such release through pannexin (Panx)-associated channels in a manner influenced by mitochondrial OXPHOS status.¹¹⁴ In the presence of ongoing cellular stressors, Panx1 channel–mediated ATP release from cardiomyocytes is amplified and can stimulate the transition of fibroblasts toward an activated myofibroblast phenotype through MAPK- and p53-dependent pathways that promote fibrotic progression.¹¹⁵ Extracellular ATP via an NLRP3/IL-1β-dependent mechanism can also mediate hypertrophic responses in cardiomyocytes under pressure overload conditions.¹¹⁶ The findings synergistically integrate mechanical strain, metabolic context, Panx1-mediated ATP release, and fibroblast activation into a unified pathophysiological framework. Nevertheless, cardiomyocyte hypertrophy and myofibroblast transdifferentiation do not constitute bona fide cellular senescence; rather, they primarily serve as indicators of a persistent stress response and a profibrotic milieu accompanying heart failure progression.

In the chronic phase of heart failure, although still poorly understood as a concept, the accumulation of senescent cells may be a significant proinflammatory factor that leads to and perpetuates inflammation, fibrosis, and microvascular changes. The beneficial effects of senolytic therapies targeting naturally occurring senescent cells are supported by studies involving HFpEF, in which elimination of senescent cells reduced circulating B-type natriuretic peptide levels and diminished inflammation, vascular remodeling, myocardial fibrosis, and endothelial rarefaction.¹¹⁷ These results implicate senescent cells in the pathophysiology of heart failure, but fail to provide evidence that ATP/P2 receptor signaling is solely responsible for the accumulation of senescent cells in heart failure. These observations, in conjunction with studies showing that fibroblasts become senescent after MI with p53-mediated regulation of collagen deposition,⁶⁹ implicate the three processes together—fibroblast senescence, SASP, and ECM remodeling—as components of a common cellular mechanism contributing to chronic remodeling during heart failure progression. In heart failure, it is ultimately not the senescence of one cell type alone but rather their interactions—between cardiomyocytes, fibroblasts, endothelial cells and immune cells—amid an energy-deprived, inflammatory, fibrotic environment over time that matters.

Chronic mechanical overload, disturbed energy metabolism and extracellular ATP release may promote inflammation, cardiomyocyte hypertrophy and fibroblast activation in heart failure. Because the clearance of senescent cells has been shown to improve HFpEF phenotypes, it is possible that cellular senescence also plays a role in heart failure remodeling. Although ATP/P2 receptor signaling may have direct effects on cellular senescence in heart failure, current evidence does not confirm this conclusion. Larger studies that will better define the temporal relationships among ATP signaling, senescent cell burden and progressive cardiac dysfunction are warranted.

Atrial Fibrillation

Atrial fibrillation (AF) is thought to be initiated and maintained by a complex interaction of abnormal atrial electrical activity and concurrent structural remodeling. Inflammatory responses, fibrosis, endothelial dysfunction and cellular senescence can together lead to alteration of atrial tissue architecture and the electrophysiological milieu. Chronic ATP/P2 receptor signaling, when acting as an underlying mechanism of inflammasome activation, oxidative tissue damage and abnormal Ca²⁺ handling in atrial muscle, may exacerbate the senescent-like remodeling changes seen in advancing age leading to electrical instability.^118,119

Senescence-associated phenotypes accumulate in atrial tissues with aging and sustained AF. Human studies have shown that the expression of senescence-associated markers, such as p53 and p16, is increased in association with thrombotic risk and endothelial dysfunction, suggesting that AF progression is a marker of age-related atrial remodeling.¹²⁰ A study has also demonstrated that markers of senescence are upregulated in atrial tissues from aged humans and patients with chronic AF. In a model of AF susceptibility post-MI, clearance of senescent myofibroblasts and endothelial cells inhibited inducibility of AF and mitigated left atrial fibrosis.¹¹⁸ These data push the pathophysiological substrate of AF from a single-cell end where cardiomyocyte electrophysiology is impaired, to a multicellular injury-, senescence- and inflammation-associated milieu in the atrium. AF-associated cardiomyocyte senescence may also involve p21, γH2AX, IL-1β, IL-6, and alterations in sarcoplasmic reticulum-related proteins, suggesting that DNA damage, inflammatory mediator secretion, and Ca²⁺ homeostasis abnormalities may jointly contribute to AF progression.¹¹⁹

In this senescence-associated atrial microenvironment, ATP/P2 receptor signaling may be involved not only in the transient regulation of electrical activity but also in pathological remodeling. Differential expression of P2Y1R and P2X4R is associated with ATP release that can affect electrophysiological differences in left vs right atrial cardiomyocytes.¹²¹ P2X7R-associated signaling could be directed from physiological electrophysiological regulation towards pathological remodeling when atrial tissue is subjected to inflammatory stimuli, sympathetic activation or metabolic stress. P2X7R-dependent NLRP3 inflammasome activation mediates AF and atrial remodeling through exposure to lipopolysaccharide (LPS) or bacterial endotoxin. Without significantly compromising the physiological function of normal atrial activity, P2X7R inhibition or genetic ablation can prevent this remodeling.¹¹⁹ As in the above-mentioned MI study, the use of a P2X7R inhibitor also reversed electrical and structural remodeling in an isoproterenol-induced AF model via the NOX/CaMKII signaling pathway.¹²² Overall, ATP/P2X7R signaling may be a pathological node between inflammasome activation, oxidative stress and abnormal Ca²⁺ handling and electrical remodeling in AF.

The duration of the AF episode is mainly determined by the development of a pro-arrhythmic substrate in which structural remodeling and electrical abnormalities reinforce each other. Chronic pressure overload can result in left atrial enlargement and a higher predisposition to developing AF prior to the onset of LV systolic dysfunction, associated with reduced Cx43 expression, altered lateral redistribution of Cx43 and interstitial fibrosis.¹²³ Such changes affect electrical coupling between atrial cardiomyocytes, augment conduction heterogeneity (spatial and temporal) and generate a substrate for re-entry formation and maintenance of functional AF. The accumulation of senescent myofibroblasts and endothelial cells can exacerbate this substrate, associated with SASP release, endothelial dysfunction and ECM deposition, further turning these inflammatory signals into fibrotic substrates with conduction abnormalities.¹¹⁸

Altogether, these findings point towards a convergence of purinergic inflammatory signaling, disturbed Ca²⁺ handling and senescence-associated structural remodeling in the progression mechanism of AF. ATP/P2 receptor signaling could participate in inducing inflammasome activation, oxidative stress and electrical remodeling, whereas senescent myofibroblasts and endothelial cells in turn amplify the process by promoting fibrosis, endothelial dysfunction and conduction heterogeneity. Collectively, these processes can establish a pathophysiological atrial milieu conducive to AF persistence and progression.

Cardiomyopathies (Dilated and Hypertrophic Cardiomyopathy)

In cardiomyopathies, ATP abnormalities are mostly characterized as abnormal myocardial metabolism and mitochondrial dysfunction. Research on disease mechanisms has shown that in hypertrophic cardiomyopathy (HCM), characterized by myocardial hypertrophy, and dilated cardiomyopathy (DCM), characterized by ventricular dilation, disease progression is associated with insufficient ATP supply, disruption of Ca²⁺ homeostasis, and ECM remodeling. Chronic metabolic stress may promote ROS accumulation, inflammatory activation, and fibrotic progression, thereby driving senescence-like alterations in cardiomyocytes and interstitial cells and creating a pathological milieu conducive to senescence-associated remodeling.^124,125

HCM is mainly characterized by the enlargement of cardiomyocytes and increased myocardial fibrosis, and may lead to heart failure with a progression of disease severity.¹²⁶ In this concept, hypertrophied myocardium is not characterized solely by an increase in wall thickness but by a state of increased energy demand with inadequate metabolic reserve. The high-energy phosphates, including ATP, ADP and phosphocreatine, are decreased in HCM myocardium together with reduced expression of mitochondria-related genes with disintegration of mitochondrial cristae structure as well, which indicates extensive energy decompensation.¹²⁴ The association between mitochondrial dysfunction and interventricular septal hypertrophy is also consistent with the concept that metabolic abnormalities may contribute to HCM phenotype aggravation rather than being merely secondary events in late-stage disease.¹²⁷ With this, ATP abnormalities in vitro and in vivo are better interpreted as metabolic stress signals active with the progressing hypertrophic myocardium than as primary pathologic drivers of HCM.

ATP abnormalities in DCM can be viewed as part of an impaired energy metabolism and progressive contractile dysfunction. DCM is defined by left ventricular enlargement and systolic impairment without evidence of coronary artery disease or pathological hemodynamic loading, the pathogenesis of which encompasses a variety of factors including inflammation and metabolic derangements.¹²⁸ When overexpressed in the mitochondria, CaMKII leads to a severe DCM phenotype in mice with decreased ATP levels, increased diastolic cytosolic Ca²⁺ concentration and reduced mechanical performance of the myocardium.¹²⁵ This is an especially pathological combination: decreased ATP supply can undermine the energetic support needed for contraction and relaxation of the myocardium while reduced Ca²⁺ reuptake will increase diastolic stress and mitochondrial burden in cardiomyocytes. Persistent stress from chronic energy deficiency, Ca²⁺ overload and mitochondrial damage may lead to a pro-ROS environment that enhances ROS accumulation, amplifies inflammation and drives the acquisition of senescence-associated cellular states. These changes cannot be directly identified as cellular senescence but rather as a basis for metabolic and Ca²⁺ homeostatic stress, generating ATP-associated metabolic strain conducive to senescence-like remodeling.

Metabolic stress is further compounded during HCM progression by microvascular dysfunction. Hypertrophic myocardium has an increased demand for oxygen, a reduced coronary flow reserve and systolic compression-induced deformation of distal intramyocardial vessels. Furthermore, proximal coronary hemodynamic abnormalities can occur due to left ventricular outflow tract obstruction.¹²⁹ Such an energy-depleted, poorly perfused microenvironment with regional ischemia may lead to chronic mitochondrial ATP deprivation, impaired Ca²⁺ homeostasis and/or long-lasting oxidative stress.

In HCM and DCM, ATP abnormalities are similarly characterized by an impairment of energy metabolism due to mitochondrial dysfunction and disrupted Ca²⁺ homeostasis, accompanied by ROS accumulation, inflammatory activation and exacerbation of interstitial fibrosis. The chronic energetic stress may therefore supply a pathological substrate for senescence-associated features across cardiomyocytes and interstitial cells, rather than indicating that cardiac hypertrophy, dilation, or fibrosis should be equated with cellular senescence. Accordingly, intracellular ATP depletion and impaired mitochondrial ATP production in cardiomyopathies should be interpreted as markers of energetic stress that may contribute to a metabolic environment permissive for senescence-associated changes, rather than as direct evidence of extracellular ATP/P2 receptor-driven AICS.

Vascular Endothelial Dysfunction

Endothelial dysfunction is a hallmark event at all stages of many CVDs and constitutes an early vascular response to injurious stimuli. It is mainly defined by decreased NO production, increased leukocyte adhesion, a prothrombotic state and altered barrier function. Given that endothelial cells can not only release ATP but also sense changes in extracellular ATP concentrations via P2 receptors, ATP/P2 receptor signaling may act as a crucial pathway through which disturbed blood flow, lipid stress, and inflammatory stimuli converge to modulate endothelial pathology.^15,87

In areas of disturbed blood flow, P2X7R expression and activity are readily upregulated; hence ATP signals are converted into local endothelial inflammatory responses via the p38 pathway.¹⁵ oxLDL, in conjunction with ATP/UTP signaling, acts synergistically under lipid stress conditions to upregulate ICAM-1 and VCAM-1 expression and increase monocyte–endothelial cell adhesion; however, the ROS-dependent adhesion response is reduced by P2Y2R intervention.⁸⁷ This suggests that ATP/P2 receptor signaling translates abnormal hemodynamic forces, lipid oxidation, and damage-associated stimuli into an inflammatory endothelial phenotype, providing the signal to endothelial cells for the transition from a homeostatic barrier to an immunologically activated interface.

Endothelial senescence converts endothelial dysfunction from a reversible activated state to a more chronic pathological vascular phenotype. Thus, replicatively senescent endothelial cells display age-related decreases in eNOS expression and bioavailability of NO, and increased adhesion to monocytes, while stable hTERT expression is sufficient to sustain an endothelium with a more youthful phenotype defined by higher eNOS/NO levels.⁹⁵ This demonstrates a causal relationship between endothelial senescence and classical dysfunction in the endothelium: loss of NO leads to impaired vasodilation and anti-inflammatory capacity, increased adhesion promotes leukocyte recruitment, whereas chronic inflammation amplifies vascular wall remodeling. On the other hand, P2Y2R-induced Src/ERK-, Rho/JNK- and p38-associated signaling pathways can mediate a prothrombotic phenotype via induction of endothelial tissue factor expression following vascular injury.^105,130 This results in a state of the endothelium that is not simply an inflammatory activation phenotype but is a functionally dysfunctional phenotype with less NO signaling, more adhesion, and greater thrombogenic potential. This dysfunctional state, when associated with ROS accumulation, DNA damage and SASP-like secretory activity, may lay the pathological foundation for the AICS hypothesis in endothelial cells.

The intensity of ATP processing and the duration of ATP signaling may govern whether injury responses in endothelium progress to a chronic pathologic state. Endothelial cells are capable of recognizing Pathogen-associated molecular patterns (PAMPs) and DAMPs, and extracellular ATP released upon inflammatory response acts as a danger signal in immune regulation. The CD39/CD73 axis regulates purinergic signaling through the conversion of ATP toward adenosine production, thereby modulating the magnitude and duration of purinergic stimulation in a tissue-specific manner.¹³¹ Activation of pannexin 1 (Panx1) channels by endogenous ATP and/or Ca²⁺ could also augment the positive feedback on NF-κB and promote endothelial cell IL-1β synthesis and release.¹³² This purinergic regulatory network, comprising ATP release, CD39/CD73-mediated nucleotide metabolism and Panx1–NF-κB feedback, enables endothelial cells to mount protective immune responses under transient stress. Yet, with a far greater oxidative load from chronic ATP exposure and a chronic inflammatory feedback loop, endothelial cells have a much greater propensity for a dysfunctional shift into a senescence-like state under this ongoing set of conditions. P2X7R/P2Y2R-mediated endothelial activation, tissue factor expression, or IL-1β release alone does not constitute endothelial senescence. These changes should be considered indicative of an endothelial senescent phenotype only when accompanied by reduced NO bioavailability, genomic instability and DNA damage, cell-cycle arrest, and SASP-like secretory activity.

The relatively well-defined vascular pathological context of endothelial dysfunction can be placed within the ATP-associated senescence hypothesis. Mediators of disturbed blood flow, lipid stress and inflammatory stimuli may potentiate ATP/P2 receptor signaling in the endothelium in concert with impaired NO/eNOS function and upregulation of adhesion molecules leading to a prothrombotic phenotype. If these changes are acute, they may involve rapid and dynamic changes in ATP; however, if they are chronic, they can be assessed alongside DNA damage, cell-cycle arrest, and SASP-like secretory activity within a broader framework for assessing AICS in endothelial cells.

Therapeutic Implications and Translational Perspectives

In the context of the hypothesis that AICS facilitates CVD progression, therapeutic translation should not be based solely on targeting a single receptor or individual senescence-related features. Instead, it must be viewed along a continuum of pathologies at multiple levels: aberrant ATP release and repeated or sustained P2 receptor activation; inflammatory amplification, chronic oxidative stress, SASP maintenance and microenvironmental remodeling. Based on the pronounced temporal dependence of ATP/purinergic signaling and senescence-associated responses, transient ATP signaling during the acute injury phase may thereby promote inflammation resolution/tissue repair, and sustained amplification of ATP/P2 receptor signaling during chronic disease stages is expected to induce a pro-senescent microenvironment/pathological tissue remodeling. Consequently, therapeutic approaches need to separate transient reparative response from pathological persistent activation and involve upstream regulation, microenvironmental manipulation and downstream targeted treatments in integrated treatment designs. The therapeutic implications discussed below span mechanistic rationale, preclinical cardiovascular evidence, and the limited human clinical evidence currently available. A graphical representation of multi-level therapeutic intervention and translational strategy associated with the hypothesis on AICS in CVD progression is illustrated in Figure 3.

Figure 3.

Multilevel intervention and translational strategy framework for CVDs based on the AICS hypothesis. Upstream stimuli such as ischemia, mechanical stress and inflammation may promote ATP release into the extracellular space and activate an extracellular ATP signaling hub mainly involving P2X7R stimulation. Persistent ATP/P2 receptor signaling may interact with ionic homeostasis disruption, redox stress and inflammatory amplification to form a pro-senescent microenvironment, thereby promoting SASP maintenance, ECM remodeling and chronic inflammation. This mechanistic framework may offer therapeutic entry points at several levels. At the upstream level, interventions may target pathological ATP release and reduce excessive purinergic signaling burden. At the microenvironmental level, combined strategies may target inflammatory amplification, oxidative stress, SASP activity and ECM remodeling. At the downstream level, senolytics may eliminate pathological senescent cells, whereas senomorphic agents may modulate SASP-associated pathways such as mTOR and NF-κB signaling. Importantly, senolytics and senomorphic agents mainly restrict senescence propagation and chronic paracrine injury, rather than directly blocking the initial occurrence of AICS. ATP/purinergic signaling and senescence-associated responses are strongly time dependent. During acute injury, these pathways may facilitate inflammatory resolution and tissue repair, whereas persistent activation during chronic disease stages is more likely to promote pathological inflammation, fibrosis and tissue remodeling. Consequently, translational strategies targeting this axis should incorporate an integrated assessment of disease stage, predominantly affected cell types, inflammatory burden, oxidative stress level and SASP activity.

Therapeutic Strategies Targeting the ATP–Purinergic Receptor Axis

ATP/P2 receptor signaling is a therapeutic target that can be more accessible; some intervention strategies do not directly target the receptors themselves but target the release of ATP, extracellular nucleotide metabolism and conversion of ATP into adenosine. As proposed in this article within the context of a model for AICS, direct reversal measures are unlikely to be particularly beneficial and the real opportunity will likely require interventions that mitigate inflammatory amplification, oxidative stress and tissue remodeling associated with ongoing extracellular ATP signaling. Thus, the ATP/P2 receptor signaling axis might be a novel therapeutic target to modulate the cardiovascular pro-senescence microenvironment.^133,134

Upon cardiovascular injury, extracellular ATP is rapidly released to function as a danger-associated signal. The P2X7R is involved in various cardiovascular pathological processes because enhanced extracellular ATP signaling induced by ischemia, mechanical stress, inflammation, and metabolic disturbances can promote NLRP3 inflammasome activation and IL-1β/IL-18 release.¹³³ Within atherosclerotic plaques, P2X7R is also associated with IL-1β release and may affect MMP9 production, indicating that the receptor plays a role not only in reinforcing inflammation but likely also in destabilizing matrix integrity.¹³⁵ Thus, it is possible that the ATP–purinergic receptor axis represents a therapeutic target of broader significance than blockade of each individual inflammatory mediator. Rather, it is a tool that tampers with upstream inflammatory, oxidative stress–promoting, and remodeling-inducing networks. Therefore, from an anti-senescence viewpoint, targeting this axis is primarily considered as modulation of a pro-senescent inflammatory microenvironment rather than as clinically validated reversal of the senescence program itself.

Such interventions can be designed at three points in this signaling axis: ATP release from cells, ectonucleotide metabolism and degradation, and receptor activation. Pathologically, PANX1 channel-mediated ATP release promotes leukocyte recruitment to injured myocardium. Oxidative stress characterized by hypoxia/reoxygenation is associated with ATP accumulation in the extracellular space and enhanced chemotactic recruitment of inflammatory cells.^136,137 Thus, controlling excessive ATP release may prevent persistent ligand availability required for lasting P2 receptor stimulation. The prevention of pro-inflammatory ATP signaling ought to be reinforced by enhancing extracellular ATP clearance and metabolic conversion. CD39 and CD73 sequentially convert extracellular ATP/ADP to AMP and then to adenosine, thereby limiting the duration of ATP-dependent P2 receptor stimulation and redirecting purinergic signaling toward adenosine receptor-mediated responses. In neutrophils, CD39/CD73-EVs suppress oxidative burst and degranulation as well as PAMP-induced IL-1β secretion through this pathway and enhance TGF-β release.¹³⁴ However, inhibition of P2X7R at the levels discussed above may block NLRP3/IL-1β-associated sympathetic nerve sprouting, inflammatory responses as well as fibrotic remodeling after MI.^138,139 Collectively, these findings provide mechanistic and preclinical support for modulating pathological ATP signaling, but do not establish that these interventions directly interrupt AICS or confer clinical benefit.

It should also be noted that therapeutic translation targeting the ATP–purinergic axis must consider the temporal dependence of ATP and adenosine signaling. Extracellular ATP does not act deleteriously and uniformly through the entire course of MI. ATP could induce a reparative macrophage phenotype in infarcted myocardium with CD301 and CD206 expression depending on the stimulation of IL-4.¹⁴⁰ Conversely, CD73 derived from T cells enhances hydrolysis of ATP/NAD and AMP after MI to facilitate cardiac wound healing through adenosine production.¹⁴¹ Together, these observations suggest that ATP/adenosine signaling is involved in immune regulation and tissue repair during the early phase following injury. Consequently, global inhibition of ATP release, broad blockade of P2 receptors or nonspecific enhancement of ATP-to-adenosine conversion could disturb physiological repair mechanisms.

The major hurdle in translating ATP/P2 receptor–targeted therapies is to distinguish pathological persistent activation from transient reparative responses. ATP/adenosine signaling may provide a feedback mechanism for inflammation resolution and tissue repair during the acute injury phase, whereas sustained activation of ATP/P2 receptors throughout chronic disease progression is likely to promote an inflammatory state, oxidative stress and senescence-associated remodeling. On the basis of this temporally and contextually dependent characteristic, therapeutic approaches should be designed to selectively decrease pathological ATP signaling load while sparing protective reparative purinergic responses.

Therapeutic Potential of Modulating Cellular Senescence and SASP

In addition to ATP/P2 receptor signaling, senescent cells and their SASP represent therapeutic downstream targets. At least following cardiovascular injury, senescent cells can leverage paracrine mechanisms to continue local inflammation, ECM remodeling and fibrotic progression due to the unique features of senescence: persistent inflammation; ROS accumulation; and DDR. Thus, the selective loss of senescent cells or inhibition of undesirable SASP action could be a crucial approach to impede long-term pro-senescent mechanisms associated with AICS.

Accumulation of cellular senescence and its deleterious counterpart, the SASP, are key nodes related to disturbances in local microenvironments tailored for optimal tissue homeostasis and ultimately systemic functional impairment. Initial studies showed that p16^INK4a-positive cells promote age-associated pathological phenotypes in most tissues, including fat tissue, skeletal muscle and the eye. Lifelong removal of these cells extended healthspan and delayed tissue dysfunctions in progeroid mice, thus supporting the causative role of cellular senescence in age-associated phenotypes.¹⁴² Within the framework of the AICS hypothesis, even if ATP release or P2 receptor activation cannot be completely suppressed, reducing senescent cell burden or attenuating their sustained paracrine effects may still alleviate chronic inflammation and remodeling stress in cardiovascular tissues.

This indicates that the beneficial effects of SASP regulation come not from antagonizing but rather from the plasticity of its phenotype. The assertion that SASP is established due to direct contributions from inflammatory signaling comes out of the fact that IL-1 signaling can regulate SASP expression, and importantly, IL-1α alone is sufficient to activate SASP. In addition, metabolic states can also reshape SASP composition; for example, during mitochondria-associated senescence, the NAD⁺/NADH balance and AMPK–p53 signaling can modulate IL-1-related SASP programs.¹⁴³ Interestingly, the ROS–NF-κB axis, p38 signaling and PI3K/Akt/mTOR pathways further promote the maintenance of SASP in a chronic way, gaining increasing consideration as potential networks for senomorphic interventions.^144–146 Their description is not repeated here, because in this section they should be regarded not as components of a fully elaborated model of SASP formation, but rather as evidence underscoring the translational significance of the concept that the SASP is neither a permanent, unchanging state nor a phenotype determined primarily by a fixed program; instead, it can be pharmacologically remodeled through inflammatory, oxidative, metabolic, and stress kinase signaling networks.

In CVDs, the benefits of senescent cell removal or SASP modulation are mostly evidenced by amelioration of vascular aging and injury-induced remodeling. In aged mice, several senolytic agents have been found to reduce aortic calcification and osteogenic signaling, as well as ameliorate vascular phenotypes under hypercholesterolemic conditions,¹⁴⁷ which implies that targeting cellular senescence with senolytic strategies may be a therapeutic strategy for both vascular calcification and age-associated vascular damage underlying the development of atherosclerosis. Moreover, D+Q treatment could also alleviate the accumulation of senescent endothelial cells with DNA damage and telomere dysfunctions, reducing the burden of endothelial senescence.¹⁴⁸ Collectively, these studies provide preclinical cardiovascular evidence that targeting senescent cells can modify vascular pathology. The current results support what is widely believed to be a mechanism of improving vascular function and remodeling phenotypes realized by targeting senescent cells or attenuating their pathologic effects, but do not provide direct evidence that the observed benefits are due to reversing senescence programs mediated by ATP/P2 receptor signaling.

Importantly, senescent cells and their secretory phenotypes do not have uniform pathological effects in all biological contexts, a consideration that is essential for translating them into applications. Recent work demonstrated that Nrf2 activation in fibroblasts is sufficient to induce cellular senescence and enhance re-epithelialization during skin wound healing in vivo. On the other hand, it is possible that the same process also promotes skin tumorigenesis, and Nrf2-activated fibroblasts can lay down a pro-senescent ECM in which plasminogen activator inhibitor-1 (PAI-1) serves as an important mediator of the senescence program.¹⁴⁹ These results imply that senescence-associated responses are not always pathogenic. In CVDs, senescent cell clearance and SASP inhibition might be most relevant in the chronic inflammation, vascular calcification, fibrosis and maladaptive remodeling phases, whereas essential senescence-associated responses involved in inflammatory resolution, scar formation and tissue repair after acute injury should be spared.

Interventions targeting senescent cells and the SASP provide a downstream therapeutic strategy for the AICS hypothesis. They directly provide the great benefit of inhibiting chronic inflammation, paracrine-mediated cellular damage, and tissue remodeling repercussions. That said, at present, and as a major limitation, evidence is lacking that these interventions reverse and/or ameliorate the outcomes of senescence programs as dictated by ATP/P2 receptor signaling. Thus, the primary barrier to clinical translation is not the global eradication of senescent cells but rather careful discernment of pathological senescent load vs reparative senescence-associated responses in conjunction with defining optimal timing and target populations for intervention as well as safety limits from more widespread impacts on tissues.

Translational Applications of Combined Anti-Inflammatory and Antioxidant Strategies

It is rare for a single regulatory component to sustain AICS responses. The mutually reinforcing nature of P2 receptor activation, accumulation of mitochondrial ROS, inflammasome activation, and maintenance of SASP makes targeting an individual mediator not entirely sufficient to tackle the entire pathological process. Combined anti-inflammatory and antioxidant strategies are particularly significant as they can concurrently mitigate chronic dysregulators of disease progression such as inflammatory amplification and oxidative stress.

Chronic ischemia, mechanical stress, metabolic disturbances and persistent low-grade inflammation could maintain upregulated levels of extracellular ATP to a point where P2X7R-mediated Ca²⁺ influx, mitochondrial dysfunction, ROS generation and inflammasome activation converge.^150,151 In turn, this can favor NF-κB-dependent SASP expression in an autocrine manner and trigger DNA damage in neighboring cells via paracrine effects. DDR, on the other hand, can also maintain SASP over sustained periods of time through signals such as TAK1, p38 and PI3K/Akt/mTOR.^144,146 Persistent purinergic signaling may therefore reinforce mitochondrial oxidative stress and SASP activity, thereby sustaining senescence-associated remodeling.

The basis for such combined therapeutic approaches is found in their mechanistic complementarity. P2X7R activation by ATP can promote IL-1α release through Ca²⁺-dependent mitochondrial ROS generation, suggesting that P2 receptor blockade and mitochondrial protection may facilitate each other.¹⁵¹ P2X7R inhibition down-regulates pro-fibrotic markers in cardiac fibroblasts from both intermediate and downstream levels, whereas the agonist 2′(3′)-O-(4-benzoylbenzoyl) ATP (BzATP) promotes TGF-β1-induced fibroblast activation at downstream levels. As such, this process relates directly to the NLRP3/IL-1 inflammasome pathway which forms the basis for potential combination therapy with P2X7R antagonism and inflammasome inhibition as well as other anti-fibrotic therapies.¹⁵² In human atherosclerotic vascular tissue, P2X7R antagonism reduced IL-1β and MMP9, indicating that P2X7R blockade can suppress inflammatory and matrix-remodeling responses within diseased vessels.¹³⁵ Related studies on relaxin have also highlighted that RXFP1, AT2R, P2X7R, TLR4, ROS and caspase-1 may act synergistically to achieve anti-inflammatory and anti-fibrotic effects, thus offering experimental support for multi-target regulatory strategies.⁸⁴

Available data currently support the individual components of these therapeutic strategies to varying degrees. Pre-clinical studies using senotherapeutic approaches suggest that targeting cellular senescence normalizes maladaptive vascular biology in cardiovascular models,¹⁵³ while clinical data from canakinumab highlight the role of IL-1β inhibition in reducing recurrent cardiovascular events.³ However, neither finding proves inhibition of ATP-induced cellular senescence. This approach, therefore, remains a mechanistically feasible yet clinically unvalidated strategy combining purinergic signaling modulation with targeting of inflammation, oxidative stress, and the SASP.

The stage of the disease also restricts the implementation of combination therapy. ATP and inflammatory signaling do not only negatively affect disease pathophysiology; therefore, it is important to consider whether there is a phase in which they are beneficial. Based on the above, moderate ATP/adenosine signaling after acute injury is believed to facilitate immune modulation and tissue recovery.¹⁴⁰ Thus, interrupting purinergic signaling too early by interfering with the consequent formation of extracellular ATP during a phase largely characterized by necrotic cell clearance and tissue repair via anti-inflammatory mechanisms may lead to shutdown of important reparative functions. However, in chronic phases dominated by inflammation, oxidative stress and fibrotic remodeling, multi-targeted therapeutic modulation might be beneficial. The clinical value of combination strategies is dependent on an integrative evaluation across disease stage, inflammatory burden and status of oxidative stress, SASP activity, and the major cell types impacted.

The integration of anti-inflammatory, antioxidant and SASP-modulating approaches shifts the AICS hypothesis from single-target intervention toward multi-process control. Its primary advantage is in addressing inflammatory amplification, mitochondrial dysfunction, and paracrine remodeling effects simultaneously. However, the greatest limitation is that signals for ATP and inflammation are not interchangeable between the acute repair phase and the chronic remodeling phase. Therapeutic effects are thus more likely to be observed in disease states with sustained pathological ATP/P2 receptor activation, chronic oxidative stress, and prolonged SASP activity than across all contexts of cardiovascular injury.

Challenges and Future Directions

Although ATP/P2 receptor signaling may contribute to cardiovascular cellular senescence-like changes and disease progression through inflammatory amplification, oxidative stress, mitochondrial injury, DDR, and SASP maintenance, this hypothesis still faces challenges related to signaling complexity, precision of anti-senescence interventions, and insufficient translational evidence. Overall, ATP signaling is not a unidirectional pro-senescent signal; its conclusive effects depend on multiple contextual determinants: cell type, receptor subtype, stimulus intensity and exposure time as well as local microenvironmental conditions and disease state. On the one hand, cellular senescence may participate in systemic chronic pathological remodeling, and on the other hand it seems to act as a double-edged sword by performing stage-specific functions during acute injury repair. Hence, subsequent research should delineate clear validation and intervention approaches from four synergistic perspectives: biological context, cellular specificity, therapeutic time windows, and quantifiable mechanistic readouts. Figure 4 illustrates the major challenges and precision translational axes for developing a hypothesis that links AICS to CVD progression.

Figure 4.

Key challenges and precision translational directions for the AICS hypothesis in CVD progression. The hypothesis linking AICS to CVD progression still faces several conceptual and translational challenges. Extracellular ATP signaling is highly context dependent, and its biological consequences are determined by cell type, receptor subtype, stimulus intensity, exposure duration, microenvironmental status and functional outcome. Thus, no single unified ATP signaling pathway can be applied to all cardiovascular pathological settings. Senescence-targeted interventions also face safety and precision challenges. Physiological or reparative senescence may participate in tissue repair, inflammatory resolution and post-injury remodeling, whereas pathological or persistent senescence may promote chronic inflammation, fibrosis and functional decline. Therefore, successful anti-senescence intervention requires well-defined therapeutic windows, predominant target cell populations and specific senescence states. Translation from basic research to clinical application is further limited by unresolved causality, model heterogeneity, incomplete mechanistic evidence, limitations of senescence markers, lack of standardized assessment systems and insufficient clinical evidence. Future studies should focus on precision strategies to define the disease contexts, cell populations, temporal windows and signaling states in which ATP contributes to pathological cardiovascular remodeling, and establish measurable, stratifiable and therapeutically actionable evaluation system.

Complexity of Specific Regulation of the ATP Signaling Pathway

The major challenge posed here for the AICS hypothesis is not that ATP participates in cardiovascular injury, but rather that ATP signaling can give rise to unique biological consequences depending on the context. This context dependence is also attributable to the role of the ATP/P2 receptor pathways in mediating acute stress responses and promoting tissue repair, as well as persistent stimulation of these same pathways that may promote enhanced inflammation, oxidative stress, and senescence-associated changes. For that reason, pro-senescent effects of ATP signaling should be seen in the context of cell type, receptor subtype, stimulus strength and diseased state.

Since ATP is a DAMP, it can activate P2X7R, the NLRP3 inflammasome and caspase-1 in inflammatory microenvironments, resulting in inflammatory cell death. Nevertheless, those results do not correlate directly with cellular senescence. Mechanistic studies on AICD demonstrate that AICD could be a consequence of different processes such as increased Ca²⁺ via P2X7R, activation of the NLRP3–caspase-1 axis, and NF-κB and PI3K–AKT/HIF pathways, opening of the mitochondrial permeability transition pore (mPTP), DNA damage and cytochrome c release.^154,155 These mechanisms suggest that ATP signaling is involved in a variety of types of cellular injury and death, although AICD data cannot be taken as evidence for the hypothesis that ATP causes cardiovascular cellular senescence directly. P2X7R is distinctive in its sensitivity to the intensity and duration of ATP stimulation. At low concentrations of ATP, cation channel opening predominates, whereas higher or sustained ATP exposure facilitates the formation of non-selective membrane pores that disrupt cellular homeostasis.¹⁵⁶ Such dose- and duration-dependent regulation between these two pathways suggests ATP signaling may functionally switch among ionic homeostasis, inflammatory activation, cell death and senescence-like responses. The ultimate biological consequences are determined by the intensity and duration of stimuli, together with the local cellular microenvironment. Extracellular ATP induces premature senescence in WI-38 human lung fibroblasts by P2Y11R-dependent phospholipase C (PLC) activation, endoplasmic-reticulum Ca²⁺ release and mitochondrial Ca²⁺ accumulation, and reactive oxygen species generation.²⁰ While based on data from a non-cardiovascular cell model, these results show that the cellular response to extracellular ATP depends on receptor subtype, ATP concentration and time of exposure, and downstream Ca²⁺–ROS signaling.

This pathological plasticity is notably observed in the cardiovascular system and shows how ATP signaling is interpreted differently by cell type. Local ATP release can serve as a tissue damage signal after acute injury by, for instance, facilitating the migration of injury-associated cells and promoting wound closure via P2Y2 receptor activation.¹⁵⁷ In differentiated VSMCs, basal autocrine ATP release signals through P2Y2R to maintain the contractile phenotype, indicating that constitutive purinergic signaling can also support vascular homeostasis.¹⁵⁸ The role of Panx1/P2X7R-associated channels in the release of cardioprotective mediators is also suggested from experiments involving ischemic preconditioning and postconditioning studies.¹⁵⁹ These findings indicate that ATP signaling may have a protective or regulatory role during acute adaptation and tissue homeostasis. By contrast, induction of long-term hypoxia, oxidative stress or chronic inflammatory lesions makes it probable that ATP/P2 receptor signaling will become chronically driven toward amplification of injurious processes in tissues. P2X3 receptor upregulation after MI has been correlated with excessive autophagy and myocardial injury through a hypoxia-induced mechanism.¹⁶⁰ P2X7R deficiency also reduces lesional inflammasome activity and ameliorates atherosclerosis in mice.²⁵ Together, these findings suggest that the effect of ATP signaling on senescence is likely context dependent, depending on factors including cell type, P2 receptor subtype, duration of exposure to ATP and existing chronic inflammatory and oxidative stress conditions.

The biological implications of ATP-mediated signaling vary at different stages of the disease and in a cell-type-dependent manner, suggesting that the association between ATP, inflammation, and senescence is context- and pathology-dependent. It has been shown in multiple studies that ATP/P2 receptor signaling is involved in pyroptosis/autophagy/hypertrophy/inflammasome activation and cardioprotection, but these biological processes cannot be intrinsically considered evidence of cellular senescence. Sympathetic nerve-derived extracellular ATP associates with NLRP3/IL-1β activity and cardiac hypertrophic responses in pressure overload models, although this process requires a continuum between adaptive remodeling and pathological amplification.¹¹⁶ Similarly, P2X7R mediates cell death in inflammatory conditions, while under ischemic preconditioning and postconditioning it can engage in the release of cardioprotective mediators through Panx1/P2X7R-associated channels.¹⁵⁹ Consequently, these ATP-associated inflammatory responses cannot be directly interpreted as senescence-inducing events, and the anti-inflammatory or tissue-protective effects noted with P2 receptor inhibition should not be simply extrapolated as anti-senescence effects.

Correspondingly, the causative engagement of extracellular ATP in cardiovascular senescence requires temporally resolved, receptor-specific and phenotypic evidence. During transient and sustained exposure, as well as after ATP withdrawal, local extracellular ATP should be monitored to assess whether senescence-associated changes are sustained. Complementary genetic and pharmacological approaches should interrogate relevant P2 receptors while excluding apoptosis, pyroptosis, other acute stress responses, and the effects of ADP, AMP, and adenosine, with longitudinal assessment of cell type-appropriate multimarker senescence phenotypes and cardiac or vascular function. The lack of change in persistent senescence phenotypes despite improvement of inflammation or tissue injury should not be construed as indicating that ATP-induced senescence has been blocked.

Safety and Precision Challenges of Anti-Senescence Interventions

The safety challenges of anti-senescence interventions in CVDs are mainly due to the duality of cellular senescence itself. If senescent cells remain long-lived, they will continuously release SASP factors over time which drive chronic inflammation, fibrosis and tissue dysfunction. Yet, at least in the early stages of acute injury, some aspects of senescent factors may instead promote repair, restructuring and restraint of uncontrolled cellular overproliferation. Thus, the key to cardiovascular anti-senescence therapy is not senescent cell clearance, but rather differentiation of pathological senescence from reparative senescence.

The role of senescent cells in injury repair depends on the specific stage and microenvironment. Senescent cardiac fibroblasts accumulate significantly after MI and express several senescence-associated regulators including p53 in infarcted hearts and hypoxia/reoxygenation-treated fibroblasts. Knocking down p53 in fibroblasts abrogates hypoxia/reoxygenation-induced cellular senescence and cytokine expression but up-regulates collagen production, while over-expressing p53 gives rise to the opposite effects.⁶⁹ The activity of SASP is also very time-dependent. Transient SASP factor exposure has been shown to elevate the regenerative potential of primary keratinocytes, while protracted exposure causes an intrinsic senescence arrest that restricts excessive stimulation of regeneration.¹⁶¹ While these conclusions come mainly from the non-cardiovascular repair paradigm, they indicate that senolytic or senomorphic approaches should not be understood as global SASP suppression of the senescence program. Instead, these strategies should be viewed as selective modulation of sustained and aberrant senescence programs.

CVDs represent a more complex target with respect to senescence because of the continuum from acute repair, inflammatory resolution, scar stabilization and chronic remodeling. An age-related increase in the number of senescent cardiomyocytes was also identified, and studies using navitoclax to clear these cells found that these mice had reduced expression of pro-fibrotic proteins as well as improved post-MI remodeling, diastolic function, and survival outcome.¹⁶² Collectively, these results provide evidence for the therapeutic manipulability of senescent burden in age or chronic cardiac injury. On the other hand, the premature senescence of fibroblasts in response to MI and pressure overload may partially curtail injury expansion or participate in reparative remodeling, while persistent activation of senescence programs in cardiomyocytes can foster cardiac dysfunction and maladaptive remodeling via paracrine activities.¹⁶³ CDC6-mediated acute cardiomyocyte senescence can play a role in early repair processes with respect to the damaging event, while depletion of senescent cells with ABT263 decreases expression of genes linked to repair following ischemic injury.¹⁶⁴ These findings indicate that the major risks associated with anti-senescence interventions arise from inadequate determination of the therapeutic time window, target cell populations, and specific senescence states.

Therapeutic precision is a particular problem for the AICS hypothesis. Although ATP/P2 receptor signaling can simultaneously affect cardiomyocytes, fibroblasts, endothelial cells and immune cells, the functions of these cell types vary greatly during acute injury and inflammatory resolution as well as chronic remodeling. The discovery that D+Q-mediated elimination of senescent non-cardiomyocytes and cardiomyocytes in the aging heart enhances remodeling and regenerative outcomes indicates therapeutic plasticity in certain senescent cell populations.¹⁶⁵ That being said, precise characterization of the origin of senescent cells, SASP composition, spatial distribution and timing with respect to other senescence-associated responses will be required for successful implementation of such anti-senescence therapies to avoid, on the one hand, excessive suppression of pathological SASP activity and, on the other hand, simultaneous inhibition of essential reparative responses.

The challenge with anti-senescence interventions is the dynamic nature of disease stage, target cell populations and senescent burden that dictates clinical value. In the case of ATP-associated interventions, simply demonstrating a decrease in senescence markers is insufficient for claiming therapeutic efficacy; one must also establish whether senescent cells promote or inhibit tissue repair and homeostasis and/or perpetuate chronic inflammation and pathological remodeling. Senotherapeutics should develop into safer and controllable approaches for treatment of CVDs only when pathological senescence responses are longer-lasting phenomena which can be tracked robustly over time.

Key Bottlenecks in Translating Basic Research into Clinical Applications

The translation of the AICS hypothesis to clinical practice needs to fill the gap between mechanistic association and disease causality. Recent investigations have demonstrated that ATP/P2 receptor signaling is involved in responses to stress and senescence-like changes, but these data have predominantly been based on in vitro studies or non-cardiovascular systems. However, the most pressing question in regard to CVDs is whether ATP/P2 receptor activation actually induces senescence in relevant vascular cell populations and whether such a senescent load can modulate disease development and clinical outcomes. Technologies for imaging senescent cells will be an essential starting point to validate it in the future. As an example, Ga-BGal PET imaging allows visualization of senescent burden in preclinical models and development of SA-β-gal–associated fluorescent or phototoxic probes represents a rational approach for identifying and targeting specific senescent cells.^166,167 Even so, these tools are still too far away from actual therapeutic decision-making in CVDs, especially since further validation is required to determine whether they can differentiate senescence signals originating from distinct cardiovascular cell populations.

Moreover, it has been reported that oxidative stress induces ATP release from human lung fibroblasts and activates a premature senescence phenotype via P2Y11R-related signaling, whereas P2 receptor blockade suppresses senescence responses induced by both oxidative stress and exogenous ATP.²⁰ These studies are mechanistic hints that ATP/P2 receptor signaling plays a role in driving senescence-like changes, but the cellular context and experimental conditions differ considerably from true cardiovascular pathophysiological environments. Expression profiles of altered P2 receptors in atherosclerotic models and human plaques further attest the cardiovascular significance of this signaling pathway.²⁵ However, these expression changes alone are associative evidence and do not provide direct evidence that ATP/P2 receptor activation is the upstream mediator of senescence in cardiomyocytes, endothelial cells, VSMCs or cardiac fibroblasts.

Another major limitation is methodological heterogeneity. Given inter-study variability in terms of ATP concentration, exposure duration, administration strategy, cellular origin as well as co-stimulatory conditions and outcome measures to assess cellular senescence, it is challenging to directly compare these studies. Moreover, there is no single highly specific marker of cellular senescence, and the commonly used markers p16^INK4a, p21, SA-β-gal, DNA damage markers or SASP factors are dependent on tissue origin, cell-cycle status, stress type, or disease stage. Widespread markers like p16^INK4a and SA-β-gal have variable expression across tissues and biological contexts, leading to a lack of reproducibility in studies as well as limited clinical extrapolation.¹⁶⁸ Without standardized ATP stimulation protocols, integrated senescence assessment systems, and cardiovascular-specific functional endpoints, positive results obtained from individual models remain difficult to directly translate into clinically relevant hypotheses.

Clinical translation is further limited by the immaturity of biomarker systems and patient stratification strategies. Circulating proteomic studies have shown that plasma proteins such as IL-23R, CCL5, and CA13 vary with aging and can be reversed by senolytic treatment, providing candidate molecular indicators for assessing systemic senescent cell burden.¹⁶⁹ Whether these circulating markers can serve as surrogates for local cardiovascular senescent burden, ATP/P2 receptor activation status, cell type-specific SASP profiles, or therapeutic responses remains to be prospectively validated. The ambiguity surrounding reliable senescence biomarkers and detection criteria, together with the absence of established clinical thresholds for tissue senescent cell burden, complicates patient enrollment, assessment of therapeutic efficacy, dose optimization, and long-term safety monitoring. The anti-inflammatory and senolytic effects of quercetin were first tested in patients undergoing CABG with a randomized placebo-controlled trial,¹⁷⁰ the results of which have already been published from this completed study (in 2025).¹⁷¹ In 97 patients, short-term quercetin treatment enhanced ex vivo endothelium-dependent relaxation and attenuated senescence- and inflammaging-associated transcriptional signatures in male but not female vascular cells. This study was performed without any measurement of extracellular ATP or P2 receptor signaling and did not include direct clinical proof for AICS. Likewise, clinical application of senolytic therapies requires stratified approaches based on senescent cell subpopulations, target tissue characteristics, disease stage, and individual risk profiles.¹⁷²

A lack of systemic cardiovascular-specific causal evidence, a lack of standardized protocols for ATP-induced stimulation and assessment criteria for senescence, and immature clinical biomarker systems and patient stratification frameworks are the main translational bottlenecks to the AICS hypothesis. The current studies have linked ATP/P2 receptor signaling to senescence-like changes, yet the evidence gaps remain striking before it can be shown that ATP/P2 receptor activation is a causal factor in cardiovascular cellular senescence and indeed contributes clinically. This will ultimately require standardized experimental paradigms, multiplexed senescence profiling modalities and deep phenotyping of systems-level stratified clinical cohorts as essential building blocks to propel this hypothesis from mechanistic correlation to causal validation and targeted therapy.

Conclusion

The association between AICS and CVDs is better considered as a model of injury-signal conversion and pathological amplification rather than a simple linear relationship whereby ATP elevation directly stimulates senescence. IRI, mechanical stress, cellular necrosis and other inflammatory stimuli favor the release of extracellular ATP, transforming ATP from an intracellular energy metabolite into a DAMP signaling molecule. Endothelial ATP release via Panx1 channels may further facilitate inflammatory processes following IRI, and stress-induced and Panx1-mediated ATP release from cardiomyocytes may likewise promote fibroblast activation and fibrosis-associated remodeling.^107,115 These results provide evidence for the notion that extracellular ATP may act as a bridge connecting acute stress responses, immune inflammation, and tissue remodeling following cardiac injury. Moreover, the relationship between extracellular ATP and cellular senescence is therefore probably not characterized by a simple direct and linear mode of AICS but rather by its capacity to induce, amplify or protract the senescent state or response program from preexisting stress-laden microenvironments.

In the present context, perhaps the most important feature of the AICS hypothesis in CVD progression is that it can offer a mechanism to explain the convergence of shared pathological phenotypes in many distinct cardiovascular conditions. Atherosclerosis, hypertension, coronary artery disease, MI and heart failure or arrhythmias possess their own initiating mechanisms; however, their progression usually features overlapping aspects such as endothelial dysfunction, inflammatory infiltration, mitochondrial impairment, ECM remodeling, and fibrosis. Evidence for the involvement of purinergic signaling in the maintenance of vascular homeostasis comes from studies demonstrating that ATP/P2Y2 signaling regulates endothelial NO production, vascular tone, and blood pressure control.⁸ IL-1α-driven SASP secretion potentially promotes an inflammatory, adhesive and atherogenic microenvironment by senescent VSMCs.⁵ Support for the link between metabolic dysfunction and cardiac functional decline was also provided by studies using models of cardiomyopathy, where ATP levels were decreased along with increased diastolic Ca²⁺ concentrations that correlated with diminished mechanical performance.¹²⁵ Nonetheless, these findings do not prove that senescence driven by ATP is an essential cause of all CVDs but rather support the idea that ATP-mediated signaling may contribute to amplifying multicellular and multistage pathological remodeling pathways.

The limits of what is available as evidence at the current time also need resolution. ATP/P2 receptor signaling involves the process of promoting biological processes including Ca²⁺ influx, inflammasome activation, mitochondrial dysfunction, pyroptosis, cardiac hypertrophy and fibroblast activation.^12,16,152 These processes are generally correlated with phenotypes associated with senescence; however, they do not directly define cellular senescence. In order to rigorously evaluate cellular senescence, multiple lines of evidence can be combined and compared across different criteria including stable cell-cycle arrest, activation of a DNA-damage response (DDR), induction/engagement of the p53/p21 or p16/Rb pathways, increased activity of SA-β-gal as well as expression profiles consistent with SASP. Importantly, ATP signaling itself is extremely context dependent because physiological release of ATP can promote NO production in the endothelium and local vasodilation.^90,157 The same purinergic signaling network may correspond to distinct biological outcomes, including repair, adaptation, inflammatory amplification, or senescence-like remodeling, depending on ATP concentration, exposure duration, receptor subtype, cellular context, and disease stage. Therefore, directly categorizing inflammation, oxidative stress, fibrosis, or hypertrophy as AICS may lead to excessive mechanistic extrapolation.

The AICS hypothesis proposed in this article suggests that sustained extracellular ATP elevation under cardiovascular injury conditions may induce or amplify cardiovascular cellular senescence through P2X/P2Y receptor-mediated Ca²⁺ dysregulation, mitochondrial ROS generation, inflammasome activation, DDR and SASP maintenance, resulting in chronic inflammation, fibrosis and tissue remodeling. Recent findings indicate that ATP/P2 receptor signaling is involved in cardiovascular inflammation and remodeling, whereas cellular senescence plays an important role in the remodeling of different types of CVDs. Nonetheless, direct causal linkage of these two processes is still not fully established, especially because it lacks validation in a cardiovascular cell type–specific and disease stage–specific manner. Hence, at present this hypothesis should be viewed as a plausible mechanistic association model and not as an established pathogenic pathway. Future studies should be aimed at elucidating whether ATP/P2 receptor activation occurs before cellular senescence and at determining whether inhibition of this signaling axis may reduce senescent cell burden and ameliorate cardiovascular outcomes.

Funding Statement

This work was supported by the Gansu Provincial Science and Technology Plan Project (Natural Science Foundation) (No. 25JRRA249); the Yunnan Key Laboratory of Innovative Diagnosis and Treatment of Circulatory Diseases (No. 20254916CE340070); the National Natural Science Foundation of China (No. 82661128); the Key Research and Development Program for International Science and Technology Cooperation of the Gansu Provincial Science and Technology Program (Nos. 23YFWA0005 and 25YFWA024); the Innovation Fund for Higher Education Institutions of Gansu Province (No. 2025A-110); the Collaborative Innovation Center for Traditional Chinese Medicine Prevention and Control of Nutrition- and Environment-Related Diseases in Northwest China (No. ZYXT-24-02); the Gansu Provincial Joint Research Fund Project (No. 24JRRA878); the 2025 Provincial Talent Program Key General Project (No. 2025RCXM006); the Natural Science Foundation of Gansu Province (No. 24JRRA1020); the Cuiying Scientific and Technological Innovation Program, Applied Basic Research General Project (No. CY2023-MS-B01); the Qihuang Talent Program of Gansu University of Chinese Medicine (Nos. ZYXKSD-202415 and ZYXKBD-202415); and the Dunhuang Medicine Natural Science Projects of Gansu University of Chinese Medicine (Nos. DHYX22-05, DHYX21-01, and DHYX21-07).

Abbreviations

AF, Atrial fibrillation; AICD, ATP-induced cell death; AICS, ATP-induced cellular senescence; AMI, Acute myocardial infarction; Ang II, Angiotensin II; APCs, Antigen-presenting cells; ATP, Adenosine triphosphate; BMDMs, Bone marrow-derived macrophages; BzATP, 2′(3′)-O-(4-benzoylbenzoyl)adenosine 5′-triphosphate; CABG, Coronary artery bypass grafting; CVDs, Cardiovascular diseases; DAMP, Damage-associated molecular pattern; DCM, Dilated cardiomyopathy; DDR, DNA damage response; ECM, Extracellular matrix; eNOS, Endothelial nitric oxide synthase; ERK, Extracellular signal-regulated kinase; HAECs, Human aortic endothelial cells; HCM, Hypertrophic cardiomyopathy; hCPCs, Human cardiac progenitor cells; HFpEF, Heart failure with preserved ejection fraction; HSCs, Hematopoietic stem cells; HSPCs, Hematopoietic stem/progenitor cells; HUVECs, Human umbilical vein endothelial cells; ICAM-1, Intercellular adhesion molecule-1; IRI, Ischemia–reperfusion injury; ISO, Isoproterenol; LPS, Lipopolysaccharide; MI/R, Myocardial ischemia/reperfusion; MI, Myocardial infarction; MINOCA, Myocardial infarction with non-obstructive coronary arteries; MMPs, Matrix metalloproteinases; mPTP, Mitochondrial permeability transition pore; mtDNA, Mitochondrial DNA; NO, Nitric oxide; NSTE-ACS, Non-ST-segment elevation acute coronary syndrome; OCT, Optical coherence tomography; OXPHOS, Oxidative phosphorylation; PAMP, Pathogen-associated molecular pattern; PBMCs, Peripheral blood mononuclear cells; RNS, Reactive nitrogen species; ROS, Reactive oxygen species; SASP, Senescence-associated secretory phenotype; SCAD, Spontaneous coronary artery dissection; T2DM, Type 2 diabetes mellitus; TLRs, Toll-like receptors; TXNIP, Thioredoxin-interacting protein; VCAM-1, Vascular cell adhesion molecule-1; VSMCs, Vascular smooth muscle cells; WAT, White adipose tissue.

Data Sharing Statement

No new data were generated or analyzed in this study. Data sharing is not applicable to this article.

Author Contributions

Xuesong Liu, Conceptualization; Investigation; Writing–original draft.

Jingjing Zhang: Conceptualization; Investigation; Writing–original draft.

Jingjing Lu: Investigation; Writing–original draft.

Zhihao Hu: Investigation; Writing–original draft.

Huiting Wei: Investigation; Writing–original draft.

Linzhu Li: Investigation; Writing–original draft.

Yufei Yang: Investigation; Writing–original draft.

Jinhai Liu: Formal analysis; Writing–review and editing.

Zhaoyu Li: Formal analysis; Writing–review and editing.

Haoling Zhang: Conceptualization; Methodology; Supervision; Project administration; Writing–review and editing.

Wangzheqi Zhang: Conceptualization; Methodology; Supervision; Project administration; Writing–review and editing.

All authors gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

All authors declare no conflicts of interest related to this article.