The SGLT2 inhibitor dapagliflozin alleviates ventricular remodeling and apoptosis after myocardial infarction by inhibiting the TGF-β1 and MAPK pathways

Abstract

Background

Heart failure and ventricular remodeling are the major cardiac injuries after myocardial infarction (MI). Sodium‒glucose cotransporter 2 (SGLT2) inhibitors have been shown to be effective at alleviating heart failure and improving patient outcomes and quality of life. However, whether SGLT2 has the same effect on myocardial infarction is unclear. The aim of this study was to elucidate the efficacy and underlying mechanisms of dapagliflozin on the outcome of myocardial infarction.

Methods

A porcine model of myocardial infarction was established via percutaneous coronary intervention with a balloon-dilated catheter and treated with dapagliflozin (DPG), an SGLT2 inhibitor, for 8 weeks. The biochemical indices of pig blood were determined. M-mode echocardiography was performed to determine cardiac structure and function. HE staining, Masson staining and TUNEL were used to detect myocardial fibrosis and apoptosis. The expression of target proteins in signal transduction pathways was determined by Western blotting.

Results

DPG treatment ameliorated myocardial hypertrophy and fibrosis and increased collagen synthesis and apoptosis induced by myocardial infarction in pigs. Moreover, DPG inhibited the activation of the TGF-β1 and MAPK signaling pathways.

Conclusion

DPG can effectively reduce ventricular remodeling and myocardial cell apoptosis after myocardial infarction. DPG inhibits the TGF-β1 and MAPK pathways.

Introduction

Myocardial infarction (MI) is a life-threatening disease that leads to insufficient blood supply to the corresponding myocardial region due to acute coronary artery occlusion, which leads to myocardial necrosis. During the first 10–15 min of myocardial ischemic necrosis, a series of myocardial structural changes, such as glycogen reduction, myofibrillar relaxation, and myofilm rupture, can be observed [1]. Elevated CK-MB, cTnI, and cTnT can be detected via biochemical tests after several hours [2, 3]. cTnI and cTnT tend to peak in the first 18–24 h after admission, and this elevated expression persists for up to seven days [4]. However, this characteristic varies individually with the individual [5]. High-sensitivity (hs)-cTn has been widely used as a biomarker of myocardial infarction in clinical practice [6].

Myocardial infarction (MI) has become the leading cause of death worldwide. Among them, the risk of death is greatly increased in patients with disease for more than 24 h [7]. This phenomenon may be related to the activation of the innate immune pathway by myocardial ischemia, which leads to a strong inflammatory response [8]. After this inflammatory phase, the myocardium enters the repair phase, which includes fibroblast proliferation, scar formation, and new blood vessel formation [9]. However, this phase often leads to ventricular remodeling and heart failure (HF).

Dapagliflozin is a novel sodium‒glucose cotransporter type 2 (SGLT-2) inhibitor. SGLT-2 inhibitors are a new type of antidiabetic drug that mainly reduces blood glucose by inhibiting the reabsorption of glucose by renal tubules [10]. SGLT-2 inhibitors have many cardiovascular benefits, including blood pressure reduction, uric acid reduction, lipid reduction, weight loss, and a reduction in inflammation and oxidation [11–13]. Since then, numerous studies have shown that SGLT-2 inhibitors are beneficial for patients with heart failure [14–17], and clinical guidelines have recommended SGLT-2 inhibitors as the standard medication for HF.

At present, SGLT-2 inhibitors have clear benefits for patients with heart failure, but the prognosis of patients with myocardial infarction is not clear. This study aimed to explore the mechanism of SGLT-2 inhibitors by investigating the effects of SGLT-2 inhibitors on inflammatory changes, fibrosis and apoptosis during the repair period of myocardial infarction and to provide a new therapeutic strategy for improving the prognosis of patients with myocardial infarction.

Methods and materials

Animal research

Ordinary English white pigs were obtained from Shanghai Jiagan Biotechnology Company. All experimental animals were maintained under standard conditions. The standard ambient temperature was maintained at 22 °C with a temperature difference of less than 4 °C, 50% air humidity, and 12 h day and night. All animal experiments were conducted by the Animal Ethics Committee of Hefei Gaoxin Cardiovascular Disease Hospital (Approval No. SYDL-2023-002).

The raw material was the balloon dilatation catheter (1.5–2.0 mm in diameter) used in coronary intervention. The balloon was cut from the proximal end, and the distal end of the balloon with metal markers was retained, generally approximately 10 mm in length, and was strictly soaked and sterilized for use.

In this study, a total of 10 experimental pigs were subjected to occlusion of the left anterior descending artery (LAD), and 5 experimental pigs were subjected to sham surgery. In brief, a guidewire was delivered through the arterial sheath to the distal left anterior descending vessel after the administration of 3% sodium pentobarbital (1.0 ml per kilogram). Then, a 1.5–2.0*20 mm balloon was placed under the guide wire, and the balloon was filled to block blood flow for 120 min. Finally, the balloon was removed, and the prepared balloon emboli were exchanged to the predetermined area. In addition to balloon expansion and embolus block, control is also performed. One week after surgery, the operation group was randomly divided into two groups: the MI + DPG group (10 mg/day, i.g.) and the MI+ Vehicle (Veh) group (i.g.). The sham operation group received the same dose of Veh at the same time.

Serological examination

The levels of aspartate aminotransferase (AST), glutamic pyruvic transaminase (ALT), blood urea nitrogen (BUN), serum creatinine (Scr), fasting blood glucose (FBG), low-density lipoprotein (LDL), creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH) and high-sensitivity cardiac troponin (hs-cTn) in each group of pig models were detected before and at 24 h and at 1 week and 9 weeks after modeling.

Ultrasonic cardiography

Echocardiography was performed on the experimental model via Doppler color ultrasound. Measurements were performed by an uninformed observer after the model was anesthetized with 3% sodium pentobarbital. The systolic activity of each segment of the left ventricle was observed via two-dimensional ultrasound. M-mode echocardiography was performed on the parasternal left ventricular long-axis view at the level of the mitral chordae tendineae. Quantitative analysis software was used to measure the left ventricular diastolic diameter, end systolic diameter and left ventricular ejection fraction. In this study, the following cardiac ultrasound parameters were measured: Ejection Fraction (EF), End-Systolic Volume (ESV), End-Diastolic Volume (EDV), Fractional Shortening (FS), Left Ventricular Internal Dimension at end-diastole (LVIDd), and Left Ventricular Internal Dimension at end-systole (LVIDs).

HE staining

After the myocardial tissue was fixed in 4% paraformaldehyde for 72 h, the tissue was dehydrated with gradient alcohol, cleared with xylene, dipped in wax, and embedded. The tissue blocks were cut into 5 μm paraffin sections via microtomy. After they were allowed to attach, the slices were deparaffinized with xylene, stained with hematoxylin and eosin, dehydrated and made transparent again. Pathomorphological changes in the left ventricular myocardium in each group were photographed and recorded.

Masson staining

Paraffin sections were prepared, affixed and deparaffinized in xylene, followed by hematoxylin staining and rinsing. The samples were hydrated with 1% hydrochloric alcohol, rinsed, blue returned to warm water, and rinsed again. Ponceau acid fuchsin was used to stain and rinse the samples. The plates were differentiated with 1% phosphomolybdic acid, counterstained with aniline blue, rinsed with 95% alcohol, dehydrated with absolute ethanol, and sealed. Changes in myocardial fibrosis were recorded via photography.

Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)

Apoptosis was analyzed via a TUNEL apoptosis assay kit (Beyotime, China) according to the manufacturer’s instructions. The nuclei stained brown yellow indicated apoptosis-positive cells. According to the distribution of apoptotic positive cells, the percentage of positive cells was calculated as the positive index of apoptotic cells under 400 high-power fields.

Western blotting

Cardiac tissue was subjected to protein extraction via a mixture of protease inhibitors (Beyotime, China) and RIPA lysis buffer (Beyotime, China). For protein extraction, a BCA protein assay kit (Beyotime, China) was used to quantify the protein concentration. Protein samples (10 µg) from different groups were electrophoresed on 10% SDS‒PAGE gels for 2 h. The proteins were transferred to a PVDF membrane (Beyotime, China) after electrophoresis. The PVDF membrane was blocked with blocking solution for 2 h at room temperature. The membranes were subsequently washed three times with TBST (Beyotime, China) for 10 min each. After washing, the cells were incubated overnight at 4 °C, and the main antibodies included TGF-β1 antibodies (1:1000, Abcam, ab9758), P38 antibodies (1:2000, CST), p-P38 antibodies (1:1000, CST), JNK antibodies (1:2000, Proteintech), p-JNK antibodies (1:1000, Proteintech), ERK antibodies (1:2000, Proteintech), and p-ERK antibodies (1:1000, Proteintech). Finally, the PVDF bands were detected via a chemiluminescence kit (1:1000, Beyotime), and the band gray values were measured via the ImageJ image analysis program.

Statistical analysis

All continuous variables in this study are presented as the means ± standard deviations. Independent sample t-tests or one-way analysis of variance (ANOVA) followed by Tukey’s post-hoc test for multiple comparisons were used for statistical analysis of continuous variables between groups. SPSS 27.0 and GraphPad Prism 9.4 were used. P < 0.05 was considered statistically significant.

Results

Effects of MI on biochemical parameters in pigs

Throughout the study, 10 experimental pigs were constructed as myocardial infarction models, and 5 experimental pigs underwent a sham operation. As shown in Table 1, before surgery, there was no significant difference in the test indices between the myocardial infarction model group and the sham operation group. After 24 h, AST, CK-MB, LDH and hs-cTn were significantly increased in the MI group. This phenomenon indicated that the myocardium of the MI group was damaged and that the MI model was successfully constructed.

Table 1.

The parameters of the myocardial infarction model were examined at before surgery and 24 h after surgery 

Variables	Before surgery		24 h after surgery
	Sham(n = 5)	MI(n = 10)	Sham(n = 5)	MI(n = 10)
AST	23.4 ± 5.41	26.90 ± 9.93	29.00 ± 16.05	170.40 ± 148.00*
ALT	62.00 ± 6.40	55.30 ± 7.50	55.00 ± 11.11	91.80 ± 57.46
BUN	2.10 ± 0.80	2.73 ± 0.69	2.45 ± 0.70	4.23 ± 1.97
Scr	97.62 ± 23.13	114.98 ± 32.73	103.08 ± 25.82	109.15 ± 25.31
FBG	4.35 ± 1.06	4.63 ± 1.10	5.75 ± 1.73	5.37 ± 2.04
LDL	0.88 ± 0.42	0.87 ± 0.15	1.15 ± 0.80	0.93 ± 0.16
CK-MB	169.80 ± 62.31	174.50 ± 107.28	131.80 ± 65.69	293.20 ± 139.84*
LDH	554.80 ± 102.17	513.90 ± 108.24	554.20 ± 152.66	1150.20 ± 617.21*
hs-cTn	1.10 ± 1.41	1.80 ± 2.41	1.10 ± 0.86	1180.31 ± 357.29**

*P<0.05, **P<0.001

Effects of DPG on biochemical parameters in pigs

As shown in Table 2, one week after the operation or sham operation, the AST and hs-cTn levels in the MI + Veh group and MI + DPG group were significantly different from those in the Sham + Veh group, and the other indicators were not significantly different. After 9 weeks of DPG or Veh feeding, there were no significant differences in the indicators among the three groups. These findings indicate that DPG has no effect on the biochemical parameters of pigs after MI.

Table 2.

The parameters of the myocardial infarction model were examined at 1 weeks and 9 weeks after surgery

Variables	1 weeks after surgery				9 weeks after surgery
	Sham + Veh(n = 5)		MI + Veh(n = 5)	MI + DPG(n = 5)	Sham + Veh(n = 5)	MI + Veh(n = 5)		MI + DPG(n = 5)
AST	26.20 ± 4.38		53.80 ± 13.85*	56.60 ± 14.47*	26.00 ± 7.42		29.40 ± 11.52	27.80 ± 14.25
ALT	59.40 ± 9.81	58.20 ± 24.36		73.80 ± 31.92	60.80 ± 8.41		58.60 ± 14.89	64.60 ± 20.28
BUN	3.79 ± 3.55	3.74 ± 1.25		3.13 ± 0.71	2.89 ± 1.17		3.39 ± 0.72	4.72 ± 2.43
Scr	111.78 ± 43.94	103.96 ± 17.40		100.46 ± 22.32	100.62 ± 18.23		117.98 ± 27.89	129.48 ± 33.93
FBG	5.19 ± 1.60	5.11 ± 2.70		5.06 ± 0.66	4.76 ± 0.84		5.13 ± 1.95	4.01 ± 0.80
LDL	0.77 ± 0.28	0.88 ± 0.21		0.75 ± 0.08	0.86 ± 0.15		0.81 ± 0.23	0.81 ± 0.21
CK-MB	172.40 ± 49.14	157.20 ± 25.92		187.60 ± 86.65	158.20 ± 76.36		173.00 ± 49.74	150.60 ± 60.17
LDH	506.80 ± 46.25	731.80 ± 170.82		984.20 ± 457.71	551.00 ± 96.33		510.80 ± 67.4	543.80 ± 70.17
hs-cTn	0.76 ± 1.48	60.00 ± 31.72*		69.82 ± 34.58*	0.70 ± 1.34		3.17 ± 3.20	3.57 ± 3.25

*P < 0.05, **P < 0.001

DPG can reduce myocardial remodeling and improve cardiac dysfunction after myocardial infarction in pigs

To assess the effects of DPG on cardiac structure and function after MI in pigs, echocardiography was performed. As shown in Fig. 1, the LVEF and LVFS were significantly lower in the MI + Veh group than in the Sham + Veh group (58.40 ± 2.35% vs. 68.54 ± 3.36% and 30.49 ± 1.78% vs. 37.46 ± 2.60%, respectively, P < 0.001). In the MI + DPG group, the LVEF and LVFS were significantly greater than those in the MI + Veh group (64.06 ± 1.95% vs. 58.40 ± 2.35% and 43.46 ± 1.79% vs. 30.49 ± 1.78%, respectively, P < 0.05). Notably, the LVEF and LVFS were significantly lower in the MI + DPG group than in the Sham + Veh group. This phenomenon indicates that DPG can reduce cardiac dysfunction after myocardial infarction, but the cardiac dysfunction caused by myocardial infarction is irreversible. Compared with those in the Sham + Veh group, the EDV, ESV, LVIDd, and LVIDs were significantly greater in the MI + Veh group. EDV, ESV, LVIDd, and LVIDs were significantly lower in the MI + DPG group than in the MI + Veh group. These results suggest that MI leads to an enlarged heart diameter and an enlarged ventricular volume and that DPG attenuates this progressive process. In conclusion, targeting DPG can attenuate myocardial remodeling and improve cardiac dysfunction after MI in pigs.

Fig. 1.

DGP treatment improves cardiac functions. A-F, EF,ESV, FS, IVIDsS were measured by echocardiobiography. G, Representative M-mode echocardiographic tracings from pig. *P<0.5, **<0.01, ***<0.001, ****P<0.0001

DPG can alleviate myocardial necrosis and myocardial fibrosis after myocardial infarction

As shown in Fig. 2, HE staining of myocardial cross-sections revealed large areas of cardiomyocyte necrosis in the MI + Veh and MI + DPG groups. After HE staining of cross-sectional myocardial sections was magnified 400-fold, HE staining revealed interstitial edema in the infarct zone, telangiectasia, necrotic muscle fibers replaced by loose fibrous connective tissue, hypertrophy of scattered viable cardiomyocytes, proliferation of fibroblasts, and formation of fibrous scars in the infarct margin. These changes were also observed in the MI + DPG group but to a lesser extent than they were in the MI group. These results also confirmed that DPG had a protective effect on MI cardiomyocytes. Masson staining revealed that the myocardial collagen content in the MI group was greater than that in the Veh group, and DPG treatment significantly alleviated the increase in collagen content induced by MI. This phenomenon implies that MI leads to myocardial fibrosis and that DPG treatment can notably slow this pathological process.

Fig. 2.

DGP treatment improved cardiac myocyte fibrosis.A. HE stained representative image of heart sections (1:40 μm) and locally magnified representatives images (1:5μm).B. Masson stained representative image of a heart section (1:80 μm).C. Quantitative analysis of the proportion of fibrosis by Masson staining. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001

DPG mitigates myocardial fibrosis and apoptosis following myocardial infarction

For TUNEL staining, normal nuclei were stained blue, and apoptotic nuclei were stained brown. As shown in Fig. 3, TUNEL indicated that MI resulted in a large area of cardiomyocyte apoptosis, which was significantly reduced in the DPG group. These findings suggest that DPG can effectively relieve the apoptosis caused by MI, thereby reducing the myocardial damage induced by MI. In the adult heart, the recovery period following myocardial infarction mainly consists of fibroblast proliferation, scar formation, and new vessel formation. Members of the TGF-β1 superfamily, which are key regulators of remodeling and fibrosis, play a role. TGF-β1 is released and activated in damaged tissue, binds to receptors and transmits signals partly through cascade activation, resulting in cardiomyocyte fibrosis and cardiac hypertrophy. Therefore, we explored the effect of DPG treatment on TGF-β1 signaling. As shown in Fig. 3, the immunoblotting results indicated that TGF-β1 expression was elevated in the MI group. Compared with the MI group, DPG significantly suppressed the expression of TGF-β1. These findings suggest that inhibition of the TGF-β1 pathway is one of the potential mechanisms by which DPG prevents myocardial remodeling.

Fig. 3.

DGP treatment improved cardiac myocyte apoptosis. A. TUNEL stained representative image of a heart section (1:40 μm) and locally magnified representative images (1:5 μm). B. The protein expressions of TgF-β. C. Quantitative analysis of apoptotic cell proportion by TUNNEL staining. D. Quantitative analysis of apoptotic cell proportion by TUNNEL staining. D. Quantitative analysis of the TgF-β and GADPH protein level. *P<0.05, **P<0.01

DPG effectively suppressed the activity of the MAPK signaling pathway

The MAPK signaling pathway also plays a crucial role in the pathological progression of myocardial remodeling and fibrosis after myocardial infarction. This signaling pathway frequently induces myocardial cell inflammation, fibrotic changes, cell apoptosis, and ventricular remodeling. MAPK signaling pathway-related proteins, such as ERK, P38, and JNK, were detected via Western blotting. As shown in Fig. 4, the results indicated that the total amounts of all the aforementioned proteins in the MI group were not significantly different from those in the Veh group. However, P-ERK, P-P38, and P-JNK were significantly expressed in the MI group, with ERK being the most significantly expressed. This phenomenon might be attributed to the close association between ERK and fibrosis. There was no statistically significant difference in total protein content between the DPG group and the MI group. In the phosphorylation assay, the expression levels of P-ERK, P-P38, and P-JNK were significantly inhibited. This outcome suggested that DPG mitigated myocardial fibrosis and ventricular remodeling by suppressing the activity of the MAPK signaling pathway. Notably, TGF-β1 has an activating effect on the MAPK signaling pathway.

Fig. 4.

DGP inhibited the expression of MAPK signaling pathway. A. Theprotein expressions of ERK, P-ERK, P38, JNK, P-JNK and GADPH. B. Quantitative analysis of the ERK and P-ERK protein level. C. Quantative analysis of the P38 and P-P38 protein level. D. Quantitative analysis of the JNK and P-JNK protein level. *P<0.05, **P<0.01, ***P<0.001, ****P<0.00001

Discussion

As a new type of hypoglycemic drug, DPG has been confirmed to significantly reduce the risk of hospitalization and death in patients with heart failure and improve the prognosis of patients [14, 18–20]. As mentioned above, myocardial infarction leads to intense inflammation. After the inflammatory phase, the myocardium enters the repair phase, which leads to fibroblast proliferation, scar formation, and new blood vessel formation, culminating in ventricular remodeling and heart failure. In this study, a porcine myocardial infarction model was established via surgery. To study the effect of dapagliflozin on the heart after myocardial infarction. In conclusion, dapagliflozin improved cardiac function by inhibiting fibroblast proliferation and apoptosis.

Over the past decade, cTn has been considered the gold standard marker for acute myocardial necrosis [21]. In the experimental model used in this study, (hs)-cTn was significantly increased after 24 h, and the other indicators were not significantly different. After 8 weeks of DPG administration, the blood indices returned to normal, and there were no statistically significant differences among the three groups. This phenomenon indicates that DPG has no effect on blood indices, which may be related to the elevation of myocardial markers; that is, DPG peaked at 24 h and returned to normal levels at approximately 1 week. In the present study, the elevation of myocardial markers and pathological changes in the myocardium confirmed that the MI model was successfully constructed and that DPG was effective in analyzing the effect of MI.

The TGF-β1 is a multifunctional cellular regulator, and its canonical Smad-dependent signaling is extensively involved in modulating cellular functions, inflammation, proliferation, differentiation, and growth [22]. Its signaling is primarily initiated by the constitutively active type II receptor (TβRII) on the cell surface and transmitted downstream via Smad proteins [23]. In cardiac pathology, TGF-β1 plays a critical role, particularly during the repair and remodeling phases following cardiac injury, where it promotes myocardial hypertrophy and fibrosis [24]. Studies indicate that directly inhibiting the TGF-β1 signaling pathway can confer protective effects on the heart. For instance, administering a TGF-β1 receptor antagonist has been shown to alleviate the extent of myocardial fibrosis in a mouse model of inflammatory cardiomyopathy [25]. Building on this, the present study demonstrates that the drug dapagliflozin reduces TGF-β1 expression levels and significantly inhibits myocardial fibrosis and apoptosis. These findings suggest that during the recovery phase of myocardial infarction, the cardioprotective effect of dapagliflozin stems from its antagonism of the TGF-β1 signaling pathway, thereby reducing fibrosis and apoptosis, and improving cardiac function.

It is noteworthy that, in addition to regulating Smad transcription, TGF-β1 also activates many non-canonical signaling pathways, such as the ERK, JNK, and P38 pathways [26–28]. These members of the MAP kinase family are involved in regulating various cellular activities, including apoptosis, gene expression, mitosis, differentiation, and immune responses [29, 30]. During the pathological processes of ventricular remodeling and cardiac hypertrophy, the three primary mitogen-activated protein kinase (MAPK) signaling pathways—ERK, JNK, and P38—are widely activated. They play crucial and interconnected roles by modulating key cellular processes in cardiomyocytes, such as growth, apoptosis, inflammation, and fibrosis: ERK is typically activated by stimuli like growth factors and mechanical stretch. Its early activation can promote adaptive concentric hypertrophy and inhibit cell death, whereas its sustained activation drives pathological cardiac hypertrophy and fibrosis; JNK and P38 persistent activation can promote the production of inflammatory factors, activate transcription factors, and influence other signaling pathways, thereby exacerbating pathological cardiac hypertrophy, cardiomyocyte apoptosis, and interstitial fibrosis [31–33]. Consequently, the activation intensity, duration, and balance among these signaling pathways collectively determine whether the cardiac remodeling process leads to compensatory adaptation or decompensated heart failure. Animal studies have shown that dapagliflozin can protect the heart by inhibiting the phosphorylation of ERK, P38, and JNK and reducing the expression of the MAPK signaling pathway [34–36]. In our study, the phosphorylation of ERK, JNK, and P38 was significantly suppressed in the dapagliflozin group. These results indicate that dapagliflozin inhibits cardiac hypertrophy and fibrosis by suppressing the phosphorylation and signaling activity of ERK, JNK, and P38.

The cardioprotective effects of SGLT2 inhibitors are likely mediated through multi-cellular mechanisms, involving direct regulation of cardiomyocytes, endothelial cells, and cardiac fibroblasts. For instance, in a heart failure with preserved ejection fraction model, empagliflozin was shown to reduce oxidative stress and inflammation, improve endothelial function, and enhance cardiomyocyte contractility by inhibiting protein kinase G oxidation, thereby alleviating diastolic dysfunction [37]. Meanwhile, in a diabetic cardiomyopathy model, dapagliflozin inhibited the TGF-β/Smad signaling pathway by activating AMPKα, reducing endothelial-mesenchymal transition and fibroblast activation, thus mitigating cardiac fibrosis [38]. Additionally, microvascular damage plays a critical role in ischemia/reperfusion injury, and SGLT2 inhibitors may improve myocardial perfusion by preserving endothelial barrier function and reducing microvascular leakage [39]. In conclusion, these drugs improve energy metabolism and reduce apoptosis by modulating calcium-handling proteins and mitochondrial function; for endothelial cells, they enhance microvascular integrity by maintaining the vascular endothelial growth factor signaling pathway and reducing adhesion molecule expression; and for cardiac fibroblasts, they suppress myofibroblast differentiation by inhibiting TGF-β1 and MAPK signaling pathways. It is particularly noteworthy that this multi-target action may explain the significant cardiovascular protective benefits observed in clinical studies, which extend beyond their glucose-lowering effects.

From the perspective of clinical transformation, these findings provide a theoretical basis for the application of SGLT2 inhibitors after myocardial infarction. At present, most clinical research focuses on patients with heart failure. However, this study confirmed through a large animal model that it has an inhibitory effect on ventricular remodeling after acute myocardial infarction, suggesting that its indications may be expanded to earlier intervention for cardiovascular events. Future research should focus on: (1) clarifying the expression and distribution characteristics of SGLT2 receptors in non-diabetic myocardium; (2) Explore the selective effects of different SGLT2 inhibitors on specific types of cardiac cells; (3) By integrating single-cell sequencing and other technologies, a specific response map of cardiac cells is drawn to provide a basis for individualized treatment.

In conclusion, SGLT2 inhibitors demonstrate unique cardiovascular protective potential by regulating cardiac cell function in multiple dimensions. It not only exerts its effects through metabolic regulatory pathways, but also generates therapeutic benefits by directly intervening in the key signaling pathways of myocardial remodeling. These mechanism studies have laid a theoretical foundation for the development of precise treatment strategies targeting specific cardiac cell types and provided a scientific basis for expanding the clinical application scenarios of SGLT2 inhibitors. More translational research is needed in the future to verify these findings and explore their synergistic effects with other cardiovascular drugs.

Conclusion

DPG had no significant effect on blood biochemistry in the pig myocardial infarction model. In terms of physiological structure, DPG can improve the cardiac ejection fraction and myocardial remodeling. DPG effectively reduces myocardial degeneration, myocardial fibrosis and myocardial cell apoptosis after myocardial infarction. DPG inhibits TGF-β1 and MAPK, which may explain the protective effect of DPG on myocardial infarction.

Strengths and limitations of the study

The experimental model for this study was a large animal, the pig. The physiological structure of pigs is more similar to that of other animals and humans. This model is more useful and reliable for studying the effects of DPG on the human body. Moreover, the indicators selected in this study are more appropriate for clinical work and are more clinically significant. Moreover, because pig models are too expensive, the risk of myocardial infarction model construction is too high, the model loss rate is high, 5 samples per group were selected in this study, and the sample size needs to be further expanded in the future.

Abbreviations

MI

Myocardial infarction

SGLT2

Sodium‒glucose cotransporter 2

DPG

Dapagliflozin

HF

Heart failure

NIH

National Institutes of Health

LAD

Left anterior descending artery

Veh

Vehicle

AST

Aspartate aminotransferase

ALT

Glutamic pyruvic transaminase

BUN

Blood urea nitrogen

Scr

Serum creatinine

FBG

Fasting blood glucose

LDL

Low-density lipoprotein

CK-MB

Creatine kinase isoenzyme

LDH

Lactate dehydrogenase

hs-cTn

High-sensitivity cardiac troponin

TUNEL

Terminal deoxynucleotidyl transferase dUTP nick end labeling

Author contributions

Conceived the research: XX. Wrote the paper: ZZ. Analyzed the data: ZZ. Revised the paper: ZZ, XX, YZ, ZF, XL, CM, QL, QZ, WZ, and HS. All the authors reviewed the manuscript.

Funding

This project was supported by the Key Research and Development Program of Anhui Province (2022e07020058).

Data availability

The data will be made available upon request.

Declarations

Ethics approval and consent to participate

All animal experiments were conducted by the Animal Ethics Committee of Hefei Gaoxin Cardiovascular Disease Hospital (Approval No. SYDL-2023-002).

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.