p53－p21通路在动脉血管平滑肌细胞衰老中的作用研究

摘要

Objective To study the effects of p53 and p21 on the aging of vascular smooth muscle cells( VSMCs) .Meth-ods Senescence associate beta-galactosidase ( SA-β-gal) staining, western-blot analysis was performed to detect VSMCs senescence induced by Angiotensin II ( Ang II ) , while 3 H-TdR and flow cytometry were used to detect VSMC proliferation and cell cycle.The VSMCs defect of p53 was primary cultured from the artery of p53 knockout mice.The overexpression of p21 on VSMCs use the method of adenovirus infection.Results After Ang II inducing, the expression of p53,p21,p16 in VSMCs increased significantly in a time dependent manner, and senescence alleviated on VSMCs with p53 defection than those with p53 wild type ( P<0.01) .p21 overexpression induced G1 phase arrest and inhibite proliferation of VSMCs.p21 overexpression increased senescence of VSMCs.Conclusion p53 and p21 may play a role in VSMC senes-cence induced by Ang II.%目的：研究p53－p21通路在血管平滑肌细胞（ vascular smooth muscle cell，VSMC）衰老中的作用。方法用血管紧张素II（ angiotensin II，Ang II）持续作用引起VSMC衰老，检测衰老相关蛋白分子的表达。利用β半乳糖苷酶（ senescence associated beta galactosidase，SA－β－gal）染色确定VSMC衰老，检测经Ang II诱导的p53敲除小鼠及其同窝野生型小鼠VSMC的衰老情况，通过感染腺病毒p21及其对照GFP的方法使VSMC中p21过表达，用3 H标记脱氧胸腺嘧啶核苷（3 H－TdR）掺入法检测p21过表达VSMC增殖，用流式细胞仪测定细胞周期。结果Ang II处理引起VSMC的p53、p21、p16表达增加，Ang II处理后使p53基因敲除的VSMC衰老细胞数明显少于其对照p53野生型鼠的VSMC（P＜0．01），过表达p21显著抑制VSMC的3H－TdR掺入（P＜0．01），并且引起细胞周期G1期阻滞；过表达p21能引起VSMC衰老。结论 p53－p21通路在Ang II引起的VSMC衰老发生过程中发挥重要作用。