Bioinformatics prediction and experimental verification of a novel microRNA for myocardial fibrosis after myocardial infarction in rats

Abstract

Background MicroRNAs (miRNAs) are endogenous noncoding single-stranded small RNAs. Numerous studies have shown that miRNAs have pivotal roles in the occurrence and development of myocardial fibrosis (MF). However, miRNA expression profile in rats with MF after myocardial infarction (MI) is not well understood. The present study aimed to find the potential miRNA for MF post MI. Methods SPF male Sprague-Dawley (SD) rat models of acute myocardial infarction (AMI) were established by ligating the anterior descending branch of the left coronary artery, while sham-operated rats were only threaded without ligation as a control group. Hematoxylin-eosin and Masson trichrome staining were used to detect myocardial histopathological changes for model evaluation. The differentially expressed miRNAs were detected by using the Agilent Rat miRNA gene chip in the myocardial tissue of the infarct marginal zone. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed by DAVID. The expression of miR-199a-5p was verified by real-time fluorescence quantitative PCR (qRT-PCR). Transfected miR-199a-5p mimics into cardiac fibroblasts (CFs) to construct cell models of miR-199a-5p overexpression. Dual-luciferase reporter assay was employed to validate the target gene of miR-199a-5p. The protein expression of the target gene in CFs transfected with miR-199a-5p mimics were detected by Western blot. Results Myocardial fibrosis was exacerbated in the model group compared with the control group. Thirteen differentially expressed miRNAs between the two groups were screened and their expression levels in the model group were all higher than those in the control group. The expression of miR-199a-5p was significantly increased in the model group in qRT-PCR, which was consistent with the results of the gene chip. KEGG enrichment analysis showed that the target genes of miR-199a-5p were enriched in the insulin signaling pathway. Furthermore, dual-luciferase reporter assay indicated that miR-199a-5p could negatively regulate the expression of GSK-3β. After transfection, the expression of miR-199a-5p was increased in the miR-199a-5p mimics group. The protein expression of GSK-3β was decreased in CFs transfected with miR-199a-5p mimics. Conclusion Our study identified miR-199a-5p could promote the progression of myocardial fibrosis after myocardial infarction by targeting GSK-3β, which provides novel targets for diagnosis and treatment of MF.

Ispinesib Mesylate-induced oxidative stress via miR-30e-5p/BCL2L11 axis in acute myocardial infarction: a comprehensive bioinformatics and experimental validation investigation

“…Nevertheless, the exact mechanism of pro-apoptotic activator's contribution to the evolution of acute myocardial infarction remains incompletely elucidated [33]. Magnetic resonance imaging (MRI) ndings indicated that elevated BCL2L11 molecular levels were intimately linked to the onset of acute myocardial infarction, indicating a de nitive causal association [34]. This investigation employed real-time uorescent quantitative PCR methodology and lentiviral infection model for cell experimentation, revealing a signi cant upregulation of BCL2L11 gene expression in individuals a icted with Acute Myocardial Infarction (AMI) [35].…”