MIR-149-5P CAN REDUCE MYOCARDIAL APOPTOSIS INDUCED BY MYOCARDIAL ISCHAEMIA REPERFUSION BY INHIBITING THE EXPRESSION OF IL-6

Quanhua Pan, Huang Su, Ding Hui, Chuanxian Hu#

Cardiac Surgery, Huaian First Hospital Affiliated to Nanjing Medical University.

Objective: To investigate the role and mechanism of miR-149-5p and its target gene IL-6 in myocardial ischaemia reperfusion injury (MI/RI) through in vitro experiments. 

Methods: The myocardial H9c2 cell ischaemia reperfusion injury model was established, and the differences of miR-149-5p expression in normal myocardial cells and MI/RI myocardial cells were detected by RT-qPCR. The target genes of miR-149-5p were predicted by bioinformatics methods, and the targeting relationship between miR-149-5p and IL-6 was proven by a luciferase assay. miR-149-5p mimics and pcDNA3.1-IL-6 were transfected into MI/RI H9c2 cells. The proportion of apoptosis was detected by flow cytometry. The protein expressions of IL-6, BCL-2 and Caspase-3 were detected by Western blot. 

Results: Compared with normal myocardial cells, the expression level of miR-149-5p was significantly reduced in myocardial cells after MI/RI, while the expression level of IL-6 was significantly increased. miR-149-5p mimics could significantly reduce the activity of IL-6 wild luciferase. In addition, miR-149-5p mimics can significantly reduce the apoptosis rate of myocardial cells, significantly reduce IL-6 and Caspase-3 and increase the protein expression level of BCL-2, while pcDNA3.1-IL-6 can significantly reverse this situation. 

Conclusion: miR-149-5p can reduce myocardial apoptosis induced by myocardial ischaemia reperfusion by inhibiting the expression of IL-6.