Tanshinone IIA improves cardiac function via regulating miR-499-5p dependent angiogenesis in myocardial ischemic mice

Myocardial ischemia-reperfusion injury leads to aggravated cardiac remodeling and heart failure. After myocardial infarction (MI), angiogenesis plays a vital role in the repair and regeneration of tissue. The purpose of the current study was to determine the effect of Tanshinone IIA (Tan IIA) on angiogenesis and elucidate its related mechanism. The C57BL/6 mice MI model was established to evaluate the therapeutic effect of Tan IIA in vivo. MicroRNA (miRNA) microarray and bioinformatics analysis were performed to determine the differential expressions of miRNAs after Tan IIA administration. Cell proliferation, migration, and angiogenesis capacity were detected by EdU, Transwell, and Tube formation assay in vitro, respectively. The relationship between miR-499-5p (miR-499) and paired phosphate and tension homolog deleted on chromosome ten (PTEN) was confirmed by using a Dual-luciferase reporter assay. Our results showed that Tan IIA administration improved cardiac function after MI by activating angiogenesis. Further miRNA microarray and bioinformatics analysis revealed that miR-499 was significantly down-regulated, while PTEN was remarkably upregulated after Tan IIA administration post-MI. In addition, we found that miR-499 knock-down effectively promotes cell proliferation, migration, and tube formation ability of HUVECs. Dual-luciferase reporter assay demonstrated that PTEN contains a direct binding site for miR-499-5p. Tan IIA improves cardiac function post-MI by inducing angiogenesis. In terms of the mechanism, Tan IIA promotes therapeutic angiogenesis by regulating miR-499-5p/PTEN signaling pathway.