血管紧张素Ⅱ1型受体相关蛋白的过表达促进血管平滑肌细胞凋亡并抑制内膜增生

摘要

目的 探讨血管紧张素Ⅱ(AngⅡ)1型受体相关蛋白(ATRAP)促进血管平滑肌细胞(VSMC)的凋亡并抑制颈动脉球囊损伤后内膜增生的可能性.方法 构建ATRAP过表达的腺病毒,转染离体VSMC及球囊损伤后的大鼠颈总动脉,利用TUNEL、荧光定量PCR、Western blot等检测细胞凋亡及凋亡相关基因的表达.结果 ATRAP转染组(Adv.ATRAP)相比对照组(Adv.GFP),VSMC凋亡率显著增加[Adv.ATRAP+AngⅡ组比Adv.GFP+AngⅡ组为(11.50±1.66)％比(1.13±0.27)％,P<0.05;Adv.ATRAP组相比Adv.GFP组为13.17±0.48比1.20±0.17,P<0.05],AngⅡ不影响ATRAP对VSMC的凋亡作用,而且过表达的ATRAP抑制AngⅡ诱导的PI3K-Akt的磷酸化;而用PTEN抑制剂(bpV)增强Akt的磷酸化后,ATRAP对VSMC凋亡的促进作用明显减弱[Adv.ATRAP+AngⅡ组相比Adv.ATRAP+AngⅡ+bpv组,(11.50±1.66)％ 比(1.81±0.19)％,P<0.05;Adv.ATRAP相比Adv.Adv.ATRAP+bpV组为(13.17±0.48)％比(1.45±0.15)％,P<0.05).Adv.ATRAP转染组相比对照组,颈动脉球囊损伤术后14 d大鼠颈总动脉内膜面积减少(P<0.05),内膜中膜比减少(P<0.05),新生内膜细胞凋亡增加(P<0.05).结论 ATRAP的过表达可能促进VSMC凋亡,从而抑制AngⅡ或球囊损伤所致的VSMC增生.%Objective To investigate the effect and mechanism of angiotensin Ⅱ type 1 receptor-associated protein (ATRAP) on the apoptosis of vascular smooth muscle cell (VSMC) and the inhibition of carotid intimal hyperplasia. Methods Adenovirus of overexpression of ATRAP was constructed and transfected into cultured VSMC and balloon injured carotid common arteries. TUNEL, real-time PCR and western blot were used to detect cell apoptosis and the expression of apoptosis-related genes, respectively. Results The apoptotic rate of VSMC was significantly increased in the ATRAP transfection group (Adv.ATRAP) compared with the control group (Adv.GFP) [ (11.50 ±1.66) ％ vs (1.13 ±0.27) ％ in Ang Ⅱ treatment groups, P<0.05;(13.17 ±0.48) ％ vs (1.20 ±0.17) ％ in non-Ang Ⅱ treatment groups, P<0.05], and the presence or absence of angiotensin (Ang Ⅱ) did not affect the extent of apoptosis. Overexpression of ATRAP inhibited the phosphorylation of Akt activated by stimulation. The increased apoptosis of VSMC in Adv.ATRAP group was significantly attenuated by PTEN inhibitor (bpV) which enhanced the phosphorylation of Akt [(11.50 ±1.66) ％vs (1.81±0.19) ％ in Ang Ⅱ treatment groups, P<0.05;(13.17±0.48) ％ vs (1.45±0.15) ％ in non-Ang Ⅱtreatment groups, P<0.05]. Neointimal formation was inhibited after incubation with Adv.ATRAP in balloon injured arteries after 14 days compared with Adv.GFP group (P<0.05). Conclusion The overexpression of ATRAP might promote the apoptosis of VSMC, thereby inhibit intimal hyperplasia after carotid balloon injury.