Serum miR-96-5p is a novel and non-invasive marker of acute myocardial infarction associated with coronary artery disease

Clinical Significance and Potential Mechanism of Circ_00008842 in Acute Myocardial Infarction

This study aimed to evaluate the clinical value of circ_0008842 in acute myocardial infarction (AMI) and explore the potential mechanisms.GSE149051 and GSE160717 datasets analyze common differentially expressed circRNAs (coDEcircRNA) in AMI. RT-qPCR analysis of circ_0008842 mRNA levels in patients with AMI. ROC curve assesses the diagnostic value of circ_0008842 in AMI. A cell model of AMI was constructed by hypoxia-reoxygenation (H/R) -induced H9c2. Cell viability and apoptosis were examined by CCK-8 and flow cytometry. Enzyme-linked immunosorbent assay was used to explore myocardial injury markers CK-MB and cTnI secretion. Dual luciferase reporter assays validate circ_0008842 binding to miRNA. PPI network and gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment reveal potential functions and pathways of targets from the miRNA in AMI.circ_0008842 is recognized as coDEcircRNA in AMI-related databases. circ_0008842 was greatly lower and miR-574-5p was significantly higher in patients with AMI than in healthy individuals. miR-574-5p is a target of circ_0008842. The sensitivity and specificity of circ_0008842 for diagnosing patients with AMI were 87.40% and 83.50%, respectively. Overexpression of circ_0008842 inhibited H/R induced apoptosis, increased cell viability, and decreased CK-MB and cTnI levels, which were partially abrogated by overexpression of miR-574-5p. Calmodulin-like protein 4 (CALML4) was the most connected hub gene in the PPI network of miR-574-5p predicted target genes.circ_0008842 is a diagnostic biomarker for AMI and participates in myocardial injury in AMI by regulating miR-574-5p. Our study provides new insights into the diagnosis for AMI.

Protective effects of ginsenoside F2 on isoproterenol-induced myocardial infarction by activating the Nrf2/HO-1 and PI3K/Akt signaling pathways

BACKGROUND

Ginsenoside F2 (GF2) serves as the principal intestinal metabolite resulting from the oral intake of Panax ginseng and Panax quinquefolius, exhibiting antioxidative, hypolipidemic, antitumor, and anti-inflammatory properties. Nevertheless, its effect on myocardial infarction (MI) is still unknown.

PURPOSE

The purpose of this study is to investigate the protective effect and the underlying mechanisms of GF2 against isoproterenol (ISO)-induced MI.

METHODS

ISO-induced H9c2 cardiomyocytes and MI rat models were utilized as in vitro and in vivo models to evaluate the impact of anti-MI of GF2. The underlying mechanisms were investigated using a variety of methodologies, including electrocardiography, Western blot analysis, histopathological examination, immunofluorescence, immunohistochemistry, and ELISA techniques.

RESULTS

In vivo experiments, our results indicated that GF2 significantly ameliorated ISO-induced electrocardiographic (ECG) abnormalities, myocardial fiber necrosis, rupture, fibrosis of myocardial tissues, and suppressed cardiac enzyme activities. Meanwhile, GF2 notably raised the activity of antioxidant enzymes like CAT, GSH, and SOD. Furthermore, it downregulated Keap1 expression level while upregulating NQO1, Nrf2, and HO-1 expression levels. Additionally, GF2 suppressed the expression of the cleaved caspase-3 and pro-apoptotic protein Bax while promoting the expression of anti-apoptotic proteins Bcl-2, p-PI3K, and p-Akt. TUNEL fluorescence results also demonstrated that GF2 effectively inhibited cardiomyocyte apoptosis. Furthermore, consistent with the results of animal experiments, GF2 considerably attenuated ROS generation, changed apoptosis and mitochondrial function, and reduced oxidative stress in ISO-induced H9c2 cardiomyocytes through activating Nrf2/HO-1 and PI3K/Akt signaling pathways.

CONCLUSION

Taken together, GF2 ameliorated MI by preventing cardiocyte apoptosis, oxidative stress, and mitochondrial dysfunction via modulating the Nrf2/HO-1 and PI3K/Akt signaling pathways, showing potential as a treatment strategy for treating MI.

CircBCL2L13 attenuates cardiomyocyte oxidative stress and apoptosis in cardiac ischemia‒reperfusion injury via miR-1246/PEG3 signaling

Ischemia‒reperfusion (I/R) is a common complication in the clinical treatment of acute myocardial infarction (MI), in which cardiomyocytes play a pivotal role in the recovery of cardiac function after reperfusion injury. The expression of numerous circular ribonucleic acids (circRNAs) is disrupted in I/R-induced cardiac damage, but the potential role of circRNAs in I/R damage has not been fully elucidated. The purpose of the present study was to clarify the biological action and molecular mechanism of circRNA 002166 (also termed circCL2L13) in postmyocardial I/R. Oxygen-glucose deprivation/reoxygenation (OGD/R) in an in vivo model was performed to simulate I/R damage. real-time polymerase chain reaction analysis was also conducted to evaluate the relationships of the SOD1, SOD2, NRF2, HO1 and GPX4 indicators with oxidative stress injury. TUNEL immunofluorescence was used to evaluate the degree of cardiomyocyte apoptosis in the different treatment groups. The circBCL2L13 level was markedly upregulated in myocardial tissues from a mouse I/R model. Overexpression of circBCL2L13 markedly attenuated the expression of oxidative stress-related genes and apoptosis in OGD/R-induced cardiomyocytes. A mechanistic study revealed that circBCL2L13 functions as a ceRNA for miR-1246 and modulates paternally expressed gene 3 (PEG3). Eventually, circBCL2L13 was proven to regulate PEG3 by targeting miR-1246, thereby protecting against OGD/R-induced cardiomyocyte oxidative damage and apoptosis. In conclusion, our study confirmed that the circBCL2L13/miR-1246/PEG3 axis suppressed the progression of OGD/R injury in cardiomyocytes, which might lead to new therapeutic strategies for cardiac I/R injury.

Molecular Characterization and Expression Changes of the bcl2l13 Gene in Response to Hypoxia in Megalobrama amblycephala

Hypoxia is a unique environmental stress, which not only reflects the insufficient oxygen supply of cells and tissues, but also occurs in various physiological and pathological environments. Mitophagy as a selective autophagy can recover and utilize damaged organelles and misfolded proteins to ensure normal cell functions and promote cell survival. Bcl2l13 (B-cell lymphoma-2 like 13) is reported to induce mitophagy as a functional mammalian homolog of Atg32. However, the function of the bcl2l13 gene is still unclear in fish. Here the sequence and structure of the bcl2l13 gene in Megalobrama amblycephala were identified and showed that bcl2l13 contained an open reading frame (ORF) of 1458 bp for encoding 485 aa. Amino acid sequence analysis indicated that Bcl2l13, as a typical anti-apoptotic protein of the Bcl2 family, contained four BH domains, one BHNo domain, and one TM domain. Further study showed that Bcl2l13 was mainly located in the mitochondria, while its localization was changed within the whole cell after the TM domain was deleted. Real-time PCR analysis revealed that bcl2l13 showed higher expression levels in early embryos. After hypoxia treatment, the mRNA levels of the bcl2l13 and autophagy-related genes were significantly up-regulated in most detected tissues, and the bcl2l13 transcription was regulated by Hif-1α mediated pathway. Additionally, the transcription activity of the bcl2l13 promoter was further analyzed using luciferase reporter assays and showed the highest activity in the promoter region from -475 to +111. These results indicated that bcl2l13 may play important roles in embryogenesis and hypoxia mediated autophagy in fish.

Machine learning-based integration develops biomarkers initial the crosstalk between inflammation and immune in acute myocardial infarction patients

Great strides have been made in past years toward revealing the pathogenesis of acute myocardial infarction (AMI). However, the prognosis did not meet satisfactory expectations. Considering the importance of early diagnosis in AMI, biomarkers with high sensitivity and accuracy are urgently needed. On the other hand, the prevalence of AMI worldwide has rapidly increased over the last few years, especially after the outbreak of COVID-19. Thus, in addition to the classical risk factors for AMI, such as overwork, agitation, overeating, cold irritation, constipation, smoking, and alcohol addiction, viral infections triggers have been considered. Immune cells play pivotal roles in the innate immunosurveillance of viral infections. So, immunotherapies might serve as a potential preventive or therapeutic approach, sparking new hope for patients with AMI. An era of artificial intelligence has led to the development of numerous machine learning algorithms. In this study, we integrated multiple machine learning algorithms for the identification of novel diagnostic biomarkers for AMI. Then, the possible association between critical genes and immune cell infiltration status was characterized for improving the diagnosis and treatment of AMI patients.

miR-96-5p regulates myocardial infarction-induced cardiac fibrosis via Smad7/Smad3 pathway

Fibrotic remodelling contributes to heart failure in myocardial infarction. MicroRNAs (miRNAs) play a crucial role in myocardial fibrosis. However, current antifibrotic therapeutic strategies using miRNAs are far from effective. In this study, we aim to investigate the effect of miR-96-5p on cardiac fibrosis. Our work reveals a significant upregulation of miR-96-5p level in the ventricular tissues of myocardial infarction mice, as well as in neonatal rat cardiac fibroblasts stimulated with TGF-β or Ang II as shown by qPCR assay. In myocardial infarction mice, miR-96-5p knockdown using antagomir alleviates the aggravated cardiac fibrosis and exacerbated myocardial function caused by myocardial infarction surgery as shown by the echocardiography and Masson's staining analysis. In contrast, immunofluorescence staining results reveal that miR-96-5p overexpression in neonatal rat cardiac fibroblasts contributes to an increase in the expressions of fibrosis-associated genes and promotes the proliferation and differentiation of cardiac fibroblasts. Conversely, miR-96-5p downregulation using inhibitor presents adverse consequences. Furthermore, Smad7 expression is downregulated in fibrotic cardiac tissues, and the Smad7 gene is identified as a direct target of miR-96-5p by dual luciferase assay. Indeed, Smad7 knockdown weakens the anti-fibrotic effect of the miR-96-5p inhibitor on cardiac fibroblasts. Moreover, Smad3 phosphorylation is elevated in fibrotic cardiac tissues, and interestingly, the Smad3 inhibitor suppresses the profibrotic effect of the miR-96-5p mimic. Taken together, our findings demonstrate that the Smad7/Smad3 signaling pathway mediates the profibrotic effect of miR-96-5p in cardiac fibrosis.

Biological properties of the BCL-2 family protein BCL-RAMBO, which regulates apoptosis, mitochondrial fragmentation, and mitophagy

Mitochondria play an essential role in the regulation of cellular stress responses, including cell death. Damaged mitochondria are removed by fission and fusion cycles and mitophagy, which counteract cell death. BCL-2 family proteins possess one to four BCL-2 homology domains and regulate apoptosis signaling at mitochondria. BCL-RAMBO, also known as BCL2-like 13 (BCL2L13), was initially identified as one of the BCL-2 family proteins inducing apoptosis. Mitophagy receptors recruit the ATG8 family proteins MAP1LC3/GABARAP via the MAP1LC3-interacting region (LIR) motif to initiate mitophagy. In addition to apoptosis, BCL-RAMBO has recently been identified as a mitophagy receptor that possesses the LIR motif and regulates mitochondrial fragmentation and mitophagy. In the 20 years since its discovery, many important findings on BCL-RAMBO have been increasingly reported. The biological properties of BCL-RAMBO are reviewed herein.

Inflammation and Oxidative Stress Role of S100A12 as a Potential Diagnostic and Therapeutic Biomarker in Acute Myocardial Infarction

Acute myocardial infarction (AMI) is one of the most serious cardiovascular diseases with high morbidity and mortality. Numerous studies have indicated that S100A12 may has an essential role in the occurrence and development of AMI, and in-depth studies are currently lacking. The purpose of this study is to investigate the effect of S100A12 on inflammation and oxidative stress and to determine its clinical applicability in AMI. Here, AMI datasets used to explore the expression pattern of S100A12 in AMI were derived from the Gene Expression Omnibus (GEO) database. The pooled standard average deviation (SMD) was calculated to further determine S100A12 expression. The overlapping differentially expressed genes (DEGs) contained in all included datasets were recognized by the GEO2R tool. Then, functional enrichment analyses, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, were carried out to determine the molecular function of overlapping DEGs. Gene set enrichment analysis (GSEA) was conducted to determine unrevealed mechanisms of S100A12. Summary receiver operating characteristic (SROC) curve analysis and receiver operating characteristic (ROC) curve analysis were carried out to identify the diagnostic capabilities of S100A12. Moreover, we screened miRNAs targeting S100A12 using three online databases (miRWalk, TargetScan, and miRDB). In addition, by comprehensively using enzyme-linked immunosorbent assay (ELISA), real-time quantitative PCR (RT-qPCR), Western blotting (WB) methods, etc., we used the AC16 cells to validate the expression and underlying mechanism of S100A12. In our study, five datasets related to AMI, GSE24519, GSE60993, GSE66360, GSE97320, and GSE48060 were included; 412 overlapping DEGs were identified. Protein-protein interaction (PPI) network and functional analyses showed that S100A12 was a pivotal gene related to inflammation and oxidative stress. Then, S100A12 overexpression was identified based on the included datasets. The pooled standard average deviation (SMD) also showed that S100A12 was upregulated in AMI (SMD = 1.36, 95% CI: 0.70-2.03, p = 0.024). The SROC curve analysis result suggested that S100A12 had remarkable diagnostic ability in AMI (AUC = 0.90, 95% CI: 0.87-0.92). And nine miRNAs targeting S100A12 were also identified. Additionally, the overexpression of S100A12 was further confirmed that it maybe promote inflammation and oxidative stress in AMI through comprehensive in vitro experiments. In summary, our study suggests that overexpressed S100A12 may be a latent diagnostic biomarker and therapeutic target of AMI that induces excessive inflammation and oxidative stress. Nine miRNAs targeting S100A12 may play a crucial role in AMI, but further studies are still needed. Our work provides a positive inspiration for the in-depth study of S100A12 in AMI.

MEK1/2 inhibitor inhibits neointima formation by activating miR-126-3p/ C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor 4 (CXCR4) axis

Endothelial dysfunction is an initial and essential step in vascular-remodeling diseases, including atherosclerosis and neointima formation. During vascular remodeling, activated endothelial cells can release pro-inflammatory factors that promote phenotypic switching of vascular smooth muscle cells (VSMCs) to the proliferative phenotype. We previously reported that MEK1/2 inhibitor, U0126, has a protective effect on the development of atherosclerosis and vascular calcification. However, the effect of MEK1/2 inhibitors on neointimal formation and the underlying mechanism is not fully understood. We determined that MEK1/2 inhibitor reduced carotid artery ligation-induced neointimal formation, while increased collagen and elastin levels and vascular integrality. Mechanistically, MEK1/2 inhibitor or ERK1/2 siRNA increased miR-126-3p level in endothelial cells, thereby inhibiting expression of regular of G-protein signaling 16 (RGS16), a miR-126-3p target gene, to activate the C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor 4 (CXCR4) signaling pathway. Accordingly, miR-126-3p was also increased by U0126 in serum and carotid artery. RGS16 was inhibited while CXCR4 and CXCL12 was increased by U0126 in neointimal areas, especially in the endothelium. Moreover, similar results were observed in atherosclerotic plaques of high-fat diet-fed apolipoprotein E deficiency (apoE^−/−) mice. In addition, vascular cell adhesion molecule 1 (VCAM-1), another miR-126-3p target gene, was reduced by U0126 in the neointimal areas, resulting reduced monocytes/macrophages accumulation. Taken together, our results indicate that MEK1/2 inhibitor can reduce neointima formation by activating endothelial miR-126-3p production to facilitate endothelium repair while reduce monocyte adhesion/infiltration.