Inhibitory effect of Sirt3 on proliferation of vascular smooth muscle cells induced by angiotensin II

Abstract Objective To detect the expression of Sirtuin3 (Sirt3) in mice vascular smooth muscle cells (VSMCs) and explore the effect of Sirt3 on VSMCs proliferation induced by angiotensin II (AngII). Methods The mRNA and protein expressions of Sirt3 in wild C57 mice VSMCs were assessed by RT-PCR and Western blotting, respectively. After the cells were exposed to various concentrations of AngII (10(-7);, 10(-6);, 10(-5); mol/L), the mRNA and protein expressions of Sirt3 were assessed again in the same way. The effect of Sirt3 on cell proliferation was observed with Edu (5-ethynyl -2'-deoxyuridine) kit after Sirt3 silencing by small interference RNA. Results Sirt3 was stably expressed in C57 mice VSMCs as revealed by Western blotting and RT-PCR, respectively. A significant increase was found in the mRNA and protein expressions of Sirt3 (P<0.01) after the stimulation of all the three different concentrations of AngII, particularly the 10(-6); mol/L group with the highest increase of Sirt3 expression, and there was a significant difference between the 10(-6); mol/L group and the other groups (P<0.05). The rate of cell proliferation in Sirt3 SiRNA group increased obviously compared to the control group (P<0.01), and the rate in the Sirt3 SiRNA+AngII group was also elevated significantly compared to the AngII group (P<0.01). Conclusion The expression of Sirt3 is stable in VSMCs; AngII can elevate the mRNA and protein expression of Sirt3 and promote the cell proliferation, what's more, Sirt3 silencing would further increase the cell proliferation.