Abstract:Aim To investigate whether SIRT6 overexpression inhibits angiotensin Ⅱ (AngⅡ)-induced cardiomyocyte apoptosis by activating adenosine 5′-monophosphate-activated protein kinase/nuclear factor erythroid 2-related factor 2/heme oxygenase-1(AMPK/Nrf2/HO-1) signaling pathway. Methods The experiment was divided into 4 groups:control group,AngⅡ group,AngⅡ+SIRT6 group, AngⅡ+empty vector (EV) group. The mRNA level of SIRT6 was detected by RT-PCR. The cell activity was measured by MTT assay. The cell apoptosis was analyzed by flow cytometry. SIRT6, cardiomyocyte apoptosis related proteins (Bax, cleaved Caspase-3, Bcl-2), DNA damage related proteins (γ-H2AX, p-ATM), AMPK/Nrf2/HO-1 signaling pathway related proteins (p-AMPK, Nrf2, HO-1) were measured by Western blot. The reactive oxygen species (ROS) content was determined by DCFH-DA staining. The changes of the above indexes among the groups were observed. Results Compared with control group, the mRNA and protein expression levels of SIRT6 and cell activity were significantly decreased in AngⅡ group. Apoptosis rate, the expressions of Bax, cleaved Caspase-3 were increased, and the expression of Bcl-2 was decreased. The expressions of γ-H2AX and p-ATM were increased, and the expressions of p-AMPK, Nrf2, HO-1 were decreased. The activity of ROS was increased (P＜0.01). Compared with AngⅡ+EV group, the expression of SIRT6 and cell activity were significantly increased in AngⅡ+SIRT6 group. Apoptosis rate, the expressions of Bax and cleaved Caspase-3 were decreased, and the expression of Bcl-2 was increased. The expressions of γ-H2AX and p-ATM were decreased, the expressions of p-AMPK, Nrf2, HO-1 were increased. The activity of ROS was decreased (P＜0.01). Conclusion SIRT6 overexpression inhibits AngⅡ-induced cardiomyocyte apoptosis through activation of AMPK/Nrf2/HO-1 signaling pathway.
