miR-222-3p targeting MEGF9 exacerbates sepsis-induced myocardial injury

Abstract

Background

Sepsis-induced myocardial injury (SIMI) commonly occurs as a complication of severe sepsis and septic shock. This research aims to explore the function of miR-222-3p inhibition in SIMI and its possible regulatory mechanisms.

Methods

A rat SIMI model was established using the cecal ligation and puncture method. In vitro experiments were conducted using lipopolysaccharide (LPS) to induce myocardial injury in H9C2 cells. miR-222-3p and MEGF9 expression were determined using qRT-PCR. Myocardial injury, inflammatory response, and oxidative stress indicators were detected using the ELISA and biochemical colorimetric assays. Cell viability and apoptosis were assessed using the CCK-8 method and flow cytometry. The interaction between miR-222-3p and MEGF9 was verified through a luciferase reporter gene assay.

Results

In the serum of rats with sepsis and LPS-induced H9C2 cells, miR-222-3p exhibited high expression, while MEGF9 was lowly expressed. Inhibition of miR-222-3p alleviated myocardial injury, inflammatory response, and oxidative stress in sepsis rats and LPS-induced cells, as evidenced by reduced CK-MB, cTnI, LDH, IL-6, IL-1β, TNF-α, and MDA level, and enhanced SOD activity. Inhibition of miR-222-3p increased LPS-induced cell viability and diminished apoptosis. miR-222-3p targeted MEGF9. Inhibiting MEGF9 expression could reverse the protective role of miR-222-3p suppression on LPS-induced myocardial injury.

Conclusion

This study’s results indicate that miR-222-3p exacerbates SIMI reactions by targeting and inhibiting MEGF9 expression. It is possible that miR-222-3p functions as a potential therapeutic target for SIMI.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s13019-026-04641-5.

Background

Sepsis, a life-threatening organ dysfunction triggered by the host’s dysregulated response to infection, represents a substantial threat to human health [1, 2]. Myocardial injury often occurs as a complication in sepsis patients. In severe cases, it can cause hypotensive shock and circulatory failure due to impaired blood circulation, ultimately leading to death [3]. Therefore, early prediction of sepsis-induced myocardial injury (SIMI) is particularly important [4]. Recent studies have shown that multiple mechanisms, including inflammatory responses, oxidative stress, and extracellular matrix remodeling, are involved in the process of SIMI [5]. Despite notable advancements in the therapeutic management of SIMI, these potential molecular mechanisms remain unclear [6]. Hence, delving deeply into the molecular mechanisms of SIMI is of great significance for optimizing early prediction methods and improving treatment outcomes, and has become a key area for breakthroughs in current research in this field.

MicroRNAs (miRNAs) represent a type of non-coding RNA with a single-stranded configuration [7]. Their key biological function is to participate in gene expression regulation, and this is mainly accomplished via two pathways: inhibiting mRNA translation or adjusting transcriptional activity [8]. During recent years, the regulatory role of miRNAs in the development of sepsis has garnered extensive interest from the research community [9]. For instance, in rats with sepsis, miR-124-3p exhibited downregulation, and the upregulation of its expression effectively ameliorated the inflammatory response, oxidative stress, and apoptosis in lipopolysaccharide (LPS)-treated H9C2 cells [10]. miR-107 could alleviate cardiomyocyte apoptosis induced by sepsis and LPS [11]. As an important small ncRNA, miR-222-3p has been demonstrated to participate in regulating various inflammatory responses, apoptosis, and organ damage processes [12]. Previous studies demonstrated that suppressing miR-222-3p promoted HPDE6-C7 cell proliferation and reduced the inflammatory response [13]. miR-222-3p treatment inhibited neuronal apoptosis in spinal cord-injured rats, enhanced neuronal cell viability and improved motor function [14]. Furthermore, Jiang et al. analyzed microarray datasets to detect differentially expressed miRNAs between normal mouse heart tissue and heart tissue affected by sepsis, and observed that miR-222-3p was significantly overexpressed [15]. However, its specific role and molecular mechanism in SIMI remain unclear.

MEGF9, a type of transmembrane protein, is thought to exert a key function in physiological processes including intercellular signaling and the regulation of inflammation [16]. Studies found that under LPS stimulation, MEGF9 expression in cardiomyocytes and mice was downregulated, and suppressing MEGF9 expression further intensified the inflammatory response and oxidative damage caused by LPS in both in vivo and in vitro settings [17]. However, whether there is a target regulatory relationship between MEGF9 and miR-222-3p, and whether there is a synergistic effect between the two in SIMI, remains to be further investigated.

To summarize, this research focused on the function of miR-222-3p in targeting and regulating MEGF9 in SIMI. The study established rat and cell sepsis models to detect changes in myocardial injury, inflammatory response, and oxidative stress. Additionally, the regulatory mechanism underlying the miR-222-3p/MEGF9 axis in SIMI was further investigated in vitro. This research offers a theoretical foundation for elucidating the molecular mechanisms of SIMI and developing potential therapeutic targets.

Methods

Animal treatment

This study used cecal ligation and puncture (CLP) to establish a rat sepsis model [18, 19]. Sprague-Dawley rats (220–250 g) were acquired from Hunan SJA Lab Animal Co., Ltd. (Hunan, China). The rats were housed in an environment with stable temperature and humidity. They were maintained under a regular light cycle, and the environment was disinfected daily. All experimental rats started the experiment one week after acclimatizing to the housing environment. Animal experiments were performed in strict compliance with animal ethics requirements. The study was conducted in agreement with the ARRIVE guidelines. Before the experiment, the rats were fasted for 12 h and anesthetized via intraperitoneal injection of 0.2% pentobarbital (10 mL/kg). After confirming that the anesthesia had taken effect, a 2 cm incision was made in the midline of the abdomen. The blind end of the cecum was ligated at the 2/3 position with a 4−0 suture, and then two perforating punctures were made on the cecum using an 18G cannula. Once the procedure was completed, the cecum was placed back into the abdominal cavity, and the abdominal wall incision was sutured in layers. Postoperatively, a subcutaneous injection of sodium chloride solution was administered. Rats in the sham surgery group (Sham) received the same surgical procedure, but the step of cecal ligation and puncture was not carried out.

Four groups were formed by randomly assigning 24 rats. 4 h post-surgery, rats in the CLP group were injected with 10 µg of miR-222-3p antagomir and 10 µg of its corresponding negative control (both reagents were synthesized by RiboBio in Guangdong, China) via the tail vein. 72 h after surgery, rats were anesthetized by inhalation with 2.5% isoflurane. Whole blood was then collected, centrifuged to separate serum, and the serum was preserved at -80°C.

Cell culture

H9C2 rat cardiomyocytes were obtained from ScienCell (Carlsbad, USA). The cells were cultured in DMEM (Gibco) containing 10% FBS (Gibco, USA) and 1% penicillin-streptomycin (Solarbio, China) under conditions of 37 °C and 5% CO₂. When the cell confluence reached 80%, LPS (Sigma, USA) was added at concentrations of 0, 1, 5, and 10 µg/mL, respectively, and the cells were incubated at 37 °C for 24 h to induce myocardial injury, thereby establishing a sepsis cell model [20].

Transfection

miR-222-3p inhibitor, si-MEGF9, and their respective negative controls were produced by GenePharma (Shanghai, China). The above-mentioned oligonucleotides were transfected into cells with Lipofectamine 3000 (Invitrogen, USA).

qRT-PCR

Total RNA was obtained from serum and cells with TRIzol (Takara, Japan). During reverse transcription, the TaqMan MicroRNA Reverse Transcription Kit (Applied Biosystems, USA) was used for miR-222-3p, while the Reverse Transcription Kit (Genecopoeia, China) was used for MEGF9. qRT-PCR were performed using SYBR Premix Ex Taq (Takara). For result analysis, U6 and GAPDH were selected as the reference genes. Finally, the 2^−ΔΔCT method was used for calculation.

ELISA

Rat serum and supernatants from transfected H9C2 cardiomyocytes were collected as test samples. Among these samples, creatine kinase MB (CK-MB), cardiac troponin I (cTnI), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) levels were determined using ELISA kits (Solarbio, China). The NT-proBNP level was detected using the N‑terminal pro‑B‑type natriuretic peptide (NT-proBNP) detection kit (Elabscience, Wuhan, China). All samples were analyzed using a microplate reader, and all testing procedures were strictly carried out in line with the instructions provided by the respective reagent kit manufacturers.

Detection of LDH, SOD, and MDA

Rat serum and supernatants from transfected H9C2 cardiomyocytes were collected as test samples. For lactate dehydrogenase (LDH) activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content, corresponding biochemical colorimetric assay kits were purchased from Nanjing Jiancheng Biotechnology Research Institute (Nanjing, China). All sample operations were carried out strictly in accordance with the manufacturer’s instructions, and the absorbance was measured using a microplate reader.

CCK-8 assay

Cells (3 × 10³/well) were plated in a 96-well plate for culture. At 0, 24, 48, and 72 h of culture, 20 µL of CCK-8 solution (5 g/L; Beyotime, China) was added to each well, after which incubation was continued at 37 °C for 2 h. Finally, the absorbance value was measured at 450 nm. In this study, blank-corrected raw OD values were directly used for plotting and statistical analysis. Raw OD data can preserve absolute cell viability differences across all time points and are more suitable for repeated-measures ANOVA to analyze longitudinal cell growth dynamics.

Flow cytometry analysis

To detect cell apoptosis, cells were first collected and stained using the Annexin V/PI Double Staining Kit (BD Biosciences, USA). Subsequently, the stained cells were incubated at room temperature in the dark for 20 min. The results were detected via an FSCAN flow cytometer (BD Biosciences) and calculated as follows: apoptotic cells/total cells × 100%.

Dual-luciferase reporter assay

TargetScan 7.2 was employed to predict potential binding sites between miR-222-3p and MEGF9. The wild-type (WT) and mutant (MUT) sequences of the MEGF9 3’UTR (encompassing the predicted miR-222-3p binding sites) were respectively inserted into the pmiR-GLO vector (Promega, USA) to generate the MEGF9-WT and MEGF9-MUT vectors. The above vectors and miR-222-3p inhibitor or inhibitor-NC were co-transfected using Lipofectamine 3000 (Invitrogen, USA). At 48 h after transfection, luciferase activity was measured utilizing the Dual-Luciferase Reporter Assay Kit (Promega, USA).

Western blot

Protein extraction and quantitative analysis were performed using RIPA lysis buffer (Thermo Fisher Scientific) and BCA protein quantification kit (Beyotime, China). Protein samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and then the samples were transferred onto a polyvinylidene fluoride (PVDF) membrane. The PVDF membrane was incubated with 5% skimmed milk at room temperature for 1 h. After washing the membrane with TBST, it was incubated with MEGF9 (Invitrogen, USA), phosphorylated AMPK (p-AMPK, CST, USA), total AMPK (t-AMPK, CST) or GAPDH (CST) primary antibodies at 4℃ overnight. After washing with TBST, the membrane was incubated with the secondary antibody at room temperature for 1 h. Protein bands were visualized using a chemiluminescence reagent (EMC Millipore, Billerica, MA, USA), and band intensities were quantified using ImageJ software.

Statistical analysis

Data analysis and graphing were carried out with GraphPad Prism 8.0 and SPSS 21.0 software. All data were represented as mean ± standard deviation. The normality of data distribution was examined using the Shapiro-Wilk test. For data that follow a normal distribution, parametric tests were employed. For comparisons between two groups, independent samples t-tests were employed, while one-way ANOVA followed by Tukey’s post-hoc test was applied to compare multiple groups. For data that did not follow a normal distribution, the Kruskal-Wallis H test and Dunn’s multiple comparison test were used. Statistical significance was defined as P < 0.05.

Results

Inhibition of miR-222-3p alleviates sepsis-induced myocardial injury in rats

To clarify the mechanism of miR-222-3p in sepsis, this study measured miR-222-3p expression in rat serum. As shown in Fig. 1A, CLP treatment increased miR-222-3p expression in rat serum, whereas administration of miR-222-3p antagomir markedly decreased its level (P < 0.001). Further ELISA analysis of serum myocardial injury markers revealed that CK-MB, cTnI, and LDH levels were significantly elevated in the CLP group (P < 0.001). Inhibition of miR-222-3p significantly reduced the levels of these myocardial injury markers (P < 0.001, Fig. 1B-D). Measurements of inflammatory and oxidative stress markers showed that IL-1β, IL-6, and TNF-α levels were enhanced in the CLP group, while SOD activity was diminished and MDA content was increased. In contrast, CLP rats treated with miR-222-3p antagomir showed reduced inflammatory responses and oxidative stress levels (P < 0.05, Fig. 1E-G). In addition, serum NT-proBNP levels were significantly increased in the CLP group, and after inhibiting miR-222-3p, its levels decreased significantly (P < 0.001, Fig. S1).

Fig. 1.

Inhibition of miR-222-3p alleviated injury in a rat model of sepsis. (A) Expression level of miR-222-3p in the serum of septic rats. (B-G) Levels of CK-MB, cTnI, LDH, IL-6, IL-1β, TNF-α, SOD, and MDA in the serum of sepsis rats treated with miR-222-3p antagomir. ^*P < 0.05, ^***P < 0.001

LPS treatment may cause myocardial injury

To clarify the effect of LPS on cardiomyocytes, H9C2 cells were treated with LPS at different concentrations (0, 1, 5, and 10 µg/mL). The results revealed that miR-222-3p expression was gradually increased with increasing LPS concentration, while cell viability was gradually downregulated (P < 0.05, Fig. 2A-B). Among these concentrations, 10 µg/mL LPS exerted the most pronounced effect; this concentration was chosen to establishconstruct the in vitro sepsis model. qRT-PCR confirmed that miR-222-3p was highly expressed in LPS-induced cells, and transfection with miR-222-3p inhibitor suppressed miR-222-3p expression (P < 0.001, Fig. 2C).

Fig. 2.

Effect of LPS on myocardial cell damage in H9C2 cells. H9C2 cells were treated with different concentrations of LPS (0, 1, 5, and 10 μg/mL). (A) qRT-PCR analysis of miR-222-3p expression in cells. (B) Cell viability assessed by CCK-8 assay. (C) qRT-PCR analysis of miR-222-3p expression in each group of cells. ns P > 0.05, ^*P < 0.05, ^**P < 0.01, ^***P < 0.001

Inhibition of miR-222-3p improves LPS-induced myocardial injury

To further investigate the impact of miR-222-3p on sepsis, cell experiments were conducted to analyze the role of miR-222-3p inhibition in LPS-induced myocardial injury. LPS treatment reduced cell viability and enhanced apoptosis, whereas inhibition of miR-222-3p significantly increased cell viability and suppressed apoptosis (P < 0.05, Fig. 3A-B). Detection of myocardial injury biomarkers revealed that CK-MB, cTnI, and LDH levels were elevated in LPS-treated cells, but these levels were significantly reduced by miR-222-3p inhibition (P < 0.05, Fig. 3C-E). Furthermore, LPS increased IL-1β, IL-6, TNF-α, and MDA levels and decreased SOD activity. However, inhibition of miR-222-3p significantly ameliorated these inflammatory and oxidative stress alterations (P < 0.05, Fig. 3F-H).

Fig. 3.

Inhibition of miR-222-3p improves LPS-induced damage to rat cardiomyocytes. (A) Cell viability assessed by CCK-8 assay. (B) Apoptosis rate of cells in each group detected by flow cytometry. (C-H) Levels of CK-MB, cTnI, LDH, IL-6, IL-1β, TNF-α, SOD, and MDA in each group detected by ELISA. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001

MEGF9 is a target gene of miR-222-3p

To identify the target genes of miR-222-3p, TargetScan 7.2 online was used to predict binding sites, which revealed complementary sequences between MEGF9 and miR-222-3p (Fig. 4A). Dual-luciferase reporter gene assay further validated that co-transfection of MEGF9-WT with miR-222-3p inhibitor significantly increased luciferase activity in H9C2 cells (P < 0.001). In contrast, no significant change in luciferase activity was observed following co-transfection with MEGF9-MUT (Fig. 4B). To explore the regulatory relationship between miR-222-3p and MEGF9 in LPS-induced myocardial injury, qRT-PCR showed that LPS significantly suppressed MEGF9 expression. Inhibition of miR-222-3p upregulated MEGF9 expression, and this effect was reversed by additional knockdown of MEGF9 (P < 0.001, Fig. 4C). Similarly, Western blot analysis revealed that, under the same treatment conditions, the expression pattern of MEGF9 protein was consistent with its mRNA levels (P < 0.05, Fig. 4D).

Fig. 4.

MEGF9 is a target of miR-222-3p. (A) Potential binding sites between miR-222-3p and the 3’UTR of MEGF9 predicted by TargetScan 7.2. (B) Validation of the interaction between miR-222-3p and MEGF9 by luciferase reporter gene assay. (C) qRT-PCR analysis of MEGF9 expression in each group of cells. (D) Western blot analysis of MEGF9 protein expression in each group of cells. ^*P < 0.05, ^***P < 0.001

miR-222-3p exacerbates myocardial injury by targeting MEGF9

To further investigate the effect of MEGF9 inhibition on the process of “inhibiting miR-222-3p to alleviate LPS-induced myocardial injury,” si-MEGF9 was further transfected into cells in the experiment. As shown in Fig. 5A-B, simultaneous inhibition of miR-222-3p and MEGF9 significantly decreased cell viability and increased apoptosis in LPS-induced cells (P < 0.05). ELISA results further revealed that co-transfection of miR-222-3p inhibitor and si-MEGF9 significantly elevated CK-MB, cTnI, LDH, IL-1β, IL-6, TNF-α, and MDA levels, and decreased SOD activity in LPS-induced cells (P < 0.05, Fig. 5C-H).

Fig. 5.

Inhibition of MEGF9 antagonizes the protective effect of miR-222-3p against LPS-induced cardiomyocyte damage. (A) Cell viability detected by CCK-8 assay. (B) Cell apoptosis rate detected by flow cytometry. (C-H) Levels of CK-MB, cTnI, LDH, IL-6, IL-1β, TNF-α, SOD, and MDA in cells detected by ELISA. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001

miR-222-3p regulates the phosphorylation of AMPK in LPS-induced myocardial injury through MEGF9

Western blot results confirmed that LPS significantly reduced the phosphorylation level of AMPK in H9C2 cells, and inhibition of miR-222-3p could significantly reverse the AMPK phosphorylation inhibition induced by LPS (Fig. 6). Further rescue experiments demonstrated that knockdown of MEGF9 could partially reverse the inhibitory effect of miR-222-3p on AMPK phosphorylation (P < 0.05). This suggests that MEGF9 is a key downstream target of miR-222-3p in regulating the AMPK signaling pathway during LPS-induced myocardial injury.

Fig. 6.

miR-222-3p regulates the phosphorylation of AMPK in LPS-induced myocardial injury through MEGF9. Western blot analysis of p-AMPK, t-AMPK, and GAPDH protein expression in each group of cells. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001

Discussion

During the progression of sepsis, it often leads to cardiac dysfunction [21]. Myocardial injury, a common and fatal complication of sepsis, significantly worsens patient prognosis [22]. Given the serious threat of SIMI to patient health and the urgent need for further research into its underlying mechanisms, this study focused on miR-222-3p and conducted systematic investigations into its function and potential molecular mechanisms in the occurrence and development of SIMI through the construction of experimental models. The study findings confirmed that miR-222-3p could further exacerbate the pathological process of SIMI by targeting and inhibiting the expression of MEGF9. The study provides new experimental evidence for in-depth analysis of the pathogenesis of SIMI.

Increasing evidence indicates that miRNAs play a crucial role as post-transcriptional regulatory factors in SIMI. They regulate inflammation, oxidative stress, apoptosis, and autophagy by targeting multiple genes [23, 24]. Recent studies have continuously expanded the miRNA regulatory network within the SIMI framework. For instance, miR-340-5p alleviated sepsis-induced cardiomyopathy by targeting MyD88-mediated oxidative stress [25]. miR-124-3p improved the inflammatory, oxidative stress, and apoptotic responses of LPS-induced H9C2 cells by targeting and regulating SP1-mediated HDAC4/HIF-1α [10]. MiR-195-5p inhibited inflammation, apoptosis, oxidative stress and endoplasmic reticulum stress in SIMI by targeting and activating ATF6 [26]. These studies consistently demonstrate that miRNAs are promising diagnostic biomarkers and therapeutic targets for SIMI.

In this study, miR-222-3p was upregulated in septic rats and LPS-induced H9C2 cells. Inhibition of miR-222-3p significantly reduced the levels of myocardial injury markers, suppressed the production of inflammatory cytokines, alleviated oxidative stress, enhanced cell viability, and reduced cell apoptosis. The experimental data demonstrated that when miR-222-3p expression was suppressed, the severity of myocardial injury in septic rats was significantly improved. These findings are highly consistent with previous research trends on miRNA in sepsis-related diseases. For example, miR-335 was upregulated in the SIMI mouse model, and miR-335 could alleviate the SIMI pathological process by inhibiting the release of inflammatory factors and myocardial cell apoptosis [27]. miR-361-5p showed high expression in the SIMI mouse model, and that inhibiting miR-361-5p expression protected the SIMI mouse model from damage caused by excessive inflammatory responses and oxidative stress [28]. The results of this study further expanded the regulatory network of miRNAs in SIMI and confirmed that miR-222-3p plays a key role in promoting damage during the development of SIMI.

It is noteworthy that previous studies have shown that miR-222-3p plays different roles in different diseases [29]. In ulcerative colitis, miR-222-3p targeted and inhibited SOCS1, activating the STAT3 signaling pathway and downregulating VDR expression, thereby exacerbating the inflammatory response [30]. In studies of chondrocyte inflammation, overexpressing miR-222-3p diminished inflammatory responses and oxidative stress levels in human chondrocytes [31]. This functional difference may be due to the tissue specificity of miR-222-3p, which allows miR-222-3p to play a dual role of “promoting damage” or “protecting” in different diseases [32–34]. The outcomes of this study demonstrate that high expression of miR-222-3p exacerbates myocardial cell damage, further confirming its functional specificity in specific tissue diseases.

Bioinformatics and dual luciferase assays confirmed that MEGF9 is a direct target gene of miR-222-3p. Our rescue experiment results showed that inhibiting MEGF9 could partially reverse the protective effect of miR-222-3p inhibition on LPS-induced myocardial injury. The results confirmed that MEGF9 is an important target gene of miR-222-3p in the regulatory process of SIMI. Recent studies confirmed that MEGF9 prevented LPS-induced cardiac dysfunction by activating the AMPK signaling pathway [17]. AMPK is a key regulator of cellular energy metabolism and oxidative stress. Its phosphorylation can effectively inhibit excessive inflammatory responses and oxidative damage in cells [35]. The activation of AMPK inhibited the JNK-NF-κB signaling cascade and downregulated the mRNA expression levels of pro-inflammatory cytokines TNF-α and IL-6 [36]. AMPK was downregulated in septic cardiomyopathy induced by LPS, and the activation of AMPK reduced the functional impairment of cardiomyocytes induced by LPS [37]. In this study, Western blot results confirmed that LPS inhibited AMPK phosphorylation; inhibition of miR-222-3p significantly increased the p-AMPK/AMPK ratio, and this effect was abolished following MEGF9 knockdown. These findings suggest that miR-222-3p exacerbates SIMI by targeting MEGF9 and inhibiting the AMPK signaling pathway. However, apart from this study, there are multiple reports that have described the specific mechanisms of MEGF9 in inflammatory diseases [17]. MEGF9 was highly expressed in patients with osteoarthritis, promoted the release of inflammatory factors, and was positively correlated with disease severity [38]. This also suggests that MEGF9 may have a broad regulatory role in various inflammatory diseases.

This study has some limitations. The assessment of myocardial injury within the heart mainly relies on serum biomarkers (CK-MB, cTnI, and LDH) and biochemical parameters. Although these markers are widely used and can reliably indicate myocardial injury, they cannot replace direct histopathological evidence. Due to the limitations of experimental conditions and resources, this study did not conduct histological analysis of the heart tissue, assessment of myocardial inflammatory infiltration, or echocardiographic measurements. In future studies, we will combine histopathological examination with cardiac ultrasound to further validate the regulatory role of the miR-222-3p/MEGF9 axis in SIMI.

Conclusions

In summary, this study confirms that miR-222-3p exhibits high expression in serum and cells, and can promote SIMI by targeting and inhibiting MEGF9 expression, thereby increasing inflammatory responses, oxidative stress, and apoptosis in cardiomyocytes. miR-222-3p has the potential to be a therapeutic target for SIMI, providing new insights and experimental evidence for elucidating the molecular pathological mechanisms of SIMI.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

W.W. D., Z.H. W., W. C. conceived and designed the experiments. W.W. D., Z.H. W., X.Y., W.W. performed the experiments and did data analysis. W.W. D., Z.H. W., X.Y. drafted the manuscript. W.W., W. C. participated in the revision of the manuscript. All authors approved the submitted version.

Funding

No funding was received for conducting this study.

Data availability

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

Animal experiments were performed in strict compliance with Animal Ethics Committee of The People’s Hospital of Tongnan District, Chongqing City. The study was conducted in agreement with the ARRIVE guidelines.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.