Screening genes associated with myocardial infarction and transverse aortic constriction using a combined analysis of miRNA and mRNA microarray

• A total of 277 DEGs and 6 key miRNAs were screened.
• An important miRNA-mRNA pair (mmu-miR-448 → SIM2) was identified.
• LOX, POSTN, SPARC, TIMP1 and SFRP2 might affect MI and TAC.

Myocardial infarction (MI) and transverse aortic constriction (TAC) are two models of cardiac hypertrophy. To study mechanisms of MI and TAC, GSE415 and GSE14267 were downloaded from Gene Expression Omnibus. GSE415 included left ventricle (LV) and intraventricular septum samples from mice that underwent MI, TAC or sham operation. GSE14267 included normal and MI samples from non-transgenic mice. Differentially expressed genes (DEGs) and microRNAs (miRNAs) were screened using limma package. Functional enrichment analysis was performed for DEGs using DAVID. Common DEGs of different groups were conducted for protein-protein interaction (PPI) analysis using STRING and visualized in PPI network by Cytoscape. Furthermore, targets were predicted for differentially expressed miRNAs using TarMir database. Totally, 277 DEGs, 31 common DEGs (e.g. SFRP2), 6 differentially expressed miRNAs (e.g. mmu-miR-448) and 1 miRNA-mRNA pair (mmu-miR-448 → SIM2) were screened out. DEGs were significantly enriched in biological processes related to muscle development and ion transportation. In the PPI network for common DEGs, LOX (degree = 7), POSTN (degree = 5), SPARC (degree = 4) and TIMP1 (degree = 3) were with higher degrees. In addition, they might function by interacting with each other (e.g. LOX-TIMP1, LOX-POSTN, SPARC-TIMP1 and SPARC-POSTN). In conclusion, LOX, POSTN, SPARC, TIMP1 and SFRP2 might affect MI and TAC.3