PAN Jialin,LIN Cong,ZHOU Lili, et al. Cardiomyocyte apoptosis induced by microRNA-34a through down-regulating Notch1[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2021, 51(5): 394-398, 403.
Abstract：Objective: To investigate the effect of microRNA-34a (miR-34a) on myocardial apoptosis and its underlying mechanism. Methods: Rat cardiomyocyte line (H9C2) was transfected with miR-34a mimics,miR-34a inhibitor, randomly synthesized miR-NC fragments, siRNA of Notch1, and randomly synthesized siRNA-NC fragments, respectively. The experiment was divided into six groups: normal group, miR-34a group,miR-inhibitor group, miR-NC group, miR-inhibitor+sirNA-Notch1 group, and miR-inhibitor+sirNA-NC group.Real-time quantitative PCR was used to analyze the expression of miR-34a. Western bolt was used to detect the expression of Caspase-3 and Notch1. The apoptosis rate of cardiomyocyte in each group was measured by Flow cytometry. Notch1 was identified as a target gene of miR-34a by dual luciferase assay. Results: Dual luciferase assay confirmed the targeting relationship between miR-34a and Notch1. Compared with the miR-NC group, the expression of miR-34a and caspase-3 was significantly increased, while the expression of Notch1 was obviously decreased, and the apoptosis rate of cardiomyocytes was apparently increased in the miR-34a group (P<0.01).Compared with the miR-NC group, the expression of miR-34a and Caspase-3 was significantly decreased, while the expression of Notch1 was obviously increased, and the apoptosis rate of cardiomyocytes was apparently decreased in the miR-inhibitor group (P<0.01). Compared with miR-inhibitor+siRNA-NC group, the expression of Notch1 and caspase-3 was significantly decreased, and the apoptosis rate of cardiomyocytes was apparently decreased in the miR-inhibitor+siRNA-Notch1 group (P<0.01). Conclusion: MiR-34a induces cardiomyocyte apoptosis through down-regulating Notch1.
