下调血管生成素样蛋白7表达对血管紧张素Ⅱ诱导的血管平滑肌细胞增殖和凋亡的影响

Effects of down-regulating expression of angiopoietin-like protein 7 on angiotensin Ⅱ-induced proliferation and apoptosis of vascular smooth muscle cells

目的 探讨下调血管生成素样蛋白7(Angptl7)表达对血管紧张素Ⅱ(AngⅡ)诱导的血管平滑肌细胞(VSMC)增殖和凋亡的影响及其作用机制。方法 采用CCK-8法检测AngⅡ诱导的VSMC生长,流式细胞术检测下调Angptl7蛋白表达对细胞周期的影响。分别采用实时荧光定量PCR和Western blot法检测转染后细胞中Angptl7 mRNA和Angptl7、周期蛋白依赖性激酶2(CDK2)、细胞周期蛋白E1、p21、Bax、Bcl-2蛋白的表达。结果 采用1μg/mL的AngⅡ处理24 h能提高VSMC活力(0.63±0.06 vs.0.37±0.06)(P<0.01),促进Angptl7 mRNA和蛋白的表达(3.05±0.21 vs.0.97±0.06和1.61±0.14 vs.1.01±0.12)(P<0.01)。下调Angptl7蛋白表达可抑制CDK2、细胞周期蛋白E1和Bcl-2蛋白的表达,促进p21和Bax蛋白的表达(P<0.05)。结论 AngⅡ能促进VSMC增殖,上调Angptl7 mRNA和蛋白表达。下调Angptl7表达可抑制AngⅡ诱导的VSMC增殖,促进细胞凋亡,从而发挥抑制血管重塑的作用。

Objective To investigate the effects of down-regulating the expression of angiopoietin-like protein 7(Angptl7) on the angiotensin Ⅱ(Ang Ⅱ)-induced proliferation and apoptosis of vascular smooth muscle cells(VSMC) and its mechanism.Methods AngⅡ-induced VSMC growth was detected by CCK-8.The effects of down-regulation of Angptl7 on the cell cycle and apoptosis were detected by flow cytometry.The expression of Angptl7 mRNA in VSMC after transfection was detected by real-time fluorescence quantitative PCR.Western blot was used to detect the protein expressions of Angptl7,cyclin-dependent kinase 2(CDK2),cyclin E1,p21,Bcl-2 and Bax.Results Angiotensin Ⅱ 1 μg/mL treatment for 24 hours increased the viability of VSMC(0.63±0.06 vs.0.37±0.06)(P<0.01),and promoted the expressions of Angptl7 mRNA and protein(3.05±0.21 vs.0.97±0.06 and 1.61±0.14 vs.1.01±0.12)(P<0.01).Down regulation of Angptl7 protein expression inhibited the protein expressions of CDK2,cyclin E1 and Bcl-2,but promoted the protein expressions of p21 and Bax(P<0.05).Conclusion AngⅡ can promote the proliferation of VSMC and up-regulate the expressions of Angptl7 mRNA and protein.Down-regulating the expression of Angptl7 can inhibit AngⅡ-induced VSMC proliferation and promote cell apoptosis, and thus play a role in inhibiting vascular remodeling.