Background: Coronary artery disease (CAD) leads to the highest mortality worldwide, seriously threatening human health. Tanshinone IIA (Tan IIA), which could be extracted from Danshen, is applied in the treatment of cardiovascular and cerebrovascular diseases. MicroRNAs (miRNAs, miRs) play pivotal roles in cell proliferation and cell apoptosis of the cardiovascular system. The aim of the present study was to explore the role of Tan IIA in CAD in vitro and the underlying molecular mechanism.
Methods: Real-time polymerase chain reaction (RT-PCR) and Western blot were used for the detection of miRNA/mRNA and protein, respectively. Target genes of miR-133a-3p were searched in TargetScan, and the targeting relationship was verified by dual-luciferase reporter assay. Cell proliferation was determined using a Cell Counting Kit-8 (CCK-8) and EdU labeling. Cell apoptosis was detected by flow cytometry and TUNEL staining.
Results: In the present study, lower miR-133a-3p level and higher epidermal growth factor receptor (EGFR; the target of miR-133a-3p) level were found in H₂O₂-induced H9c2 cells. In addition, Tan IIA upregulated miR-133a-3p and downregulated EGFR expression. Moreover, Tan IIA promoted cell proliferation and suppressed apoptosis and enhanced G0/G1, which was reversed by miR-133a-3p inhibitor, while siRNA-EGFR abolished the effects induced by miR-133a-3p in H₂O₂-induced H9c2 cells.
Conclusion: Tan IIA reversed H₂O₂-induced cell proliferation reduction, cell apoptosis induction, and G0/G1 arrest reduction in H9c2 cells by miR-133a-3p/EGFR axis. The findings suggested a potential molecular basis of Tan IIA in treating patients with CAD.
Keywords: tanshinone IIA, coronary artery disease, miR-133a-3p, EGFR