| ABSTRACT：Objective: To investigate the effect of microRNA-363-5p targeted binding to THBS3 on angiotensin II-induced apoptosis in cardiomyocytes and its molecular mechanism. Methods: A human-derived cardiomyocyte cell line (AC16) was used to establish an in vitro cardiomyocyte apoptosis model with angiotensin II (AngII), and a dual luciferase reporter assay was performed to detect the relationship between miR-363-5p and THBS3; apoptosis rate was detected by flow cytometry, and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was performed to detect the relative expression of microR-363-5p, ATF- 6mRNA, THBS3mRNA expression; Western Blot to detect the relative expression of caspase-12, caspase-3, GRP78, Bax, Bcl-2.Results:(1) Compared with the control group, the relative expression level of miR-363-5p in AngII group was significantly decreased.（2）Compared with Mir-inhibitor-NC and Mir-mimics-NC groups, the apoptosis rate of miR-inhibitor and miR-mimics groups was significantly increased and decreased, the relative expression level of Bax protein was significantly increased and decreased, and the relative expression level of Bcl-2 was decreased and increased. (3) miR-363-5p targeted binding to THBS3. (4) Compared with the THBS3-OENC group, the relative expression of Bax and caspase-3 proteins was significantly higher, the relative expression of Bcl-2 protein was significantly lower, and the apoptosis rate was higher in the THBS3-OE group. (5) Compared with the negative control group, the relative expression of Bax and caspase-3 proteins in the miR-mimcs+THBS3-OE group was significantly higher, the relative expression of Bcl-2 protein was significantly lower, the apoptosis rate was significantly higher, and the cell viability was significantly lower. (6) Compared with the miR-inhibitor group, the relative expression of GRP78 and caspase-12 was decreased in the miR-inhibitor-4-PBA group, and the apoptosis rate was significantly reduced. (7) Compared with the negative control group, the apoptosis rate was elevated in the ATF-6-OE group, and the relative expression of caspase-12 was significantly increased. (8) Compared with the negative control group, miR-inhibitor+ATF-6 siRNA group showed decreased apoptosis rate and decreased relative expression of caspase-12. Conclusions: MicroRNA-363-5p is able to target binding to THBS3 to regulate myocardial apoptosis, a process that may be mediated through the endoplasmic reticulum stress ATF-6 pathway. |
