Xu D, Wang M, Liu Y
Department of Cardiology, Nanfang Hospital, The First Military Medical University, Guangzhou 510515, China.
Zhonghua Yi Xue Za Zhi. 2001 Jun 10;81(11):680-3.
To investigate the role p27, p21, and p57, different cyclin-dependent kinase inhibitors (CKIs), play in the hyperplasia and hypertrophy of vascular smooth muscle cells (VSMCs) stimulated with platelet-derived growth factor (PDGF-BB) and angiotensin II (Ang II).
VSMCs from rat aorta were cultured. PDGF-BB and Ang II were added into the serum-free media at the concentrations of 10 - 6 M and 20 ng/ml respectively. VSMCs were harvested after 6h, 12h, and 24 h or stimulation. The protein levels of p27, p21 and p57 in VSMCs were examined with Western blot analysis.
The protein levels of p27, p21, and p57 in the Ang II-stimulated VSMCs were similar to those in the quiescent cells (P > 0.05). The protein levels of p21 and p57 in the PDGF-BB-stimulated VSMCs increased along with the time course of stimulation, the former being at its peak value at the 24th hour, and were significantly higher than those in Ang II-stimulated VSMCs. However, the p57 protein level was high in the quiescent cells. A remarkable decrease of the p57 protein level was found in the PDGF-BB-stimulated VSMCs (P < 0.01).
p27, p21, and p57 proteins play important roles in regulating hyperplasia and hypertrophy of VSMC. P21 and p57 prevent the overplasia of VSMCs. P27 is the most important regulator of hyperplasia and hypertrophy of VSMC stimulated by PDGF and Ang II.
研究不同的细胞周期蛋白依赖性激酶抑制剂（CKIs）p27、p21和p57在血小板衍生生长因子（PDGF-BB）和血管紧张素II（Ang II）刺激下血管平滑肌细胞（VSMCs）的增生和肥大过程中所起的作用。
培养大鼠主动脉的VSMCs。分别以10 - 6 M和20 ng/ml的浓度将PDGF-BB和Ang II添加到无血清培养基中。刺激6小时、12小时和24小时后收获VSMCs。采用蛋白质印迹分析检测VSMCs中p27、p21和p57的蛋白水平。
Ang II刺激的VSMCs中p27、p21和p57的蛋白水平与静止细胞中的相似（P > 0.05）。PDGF-BB刺激的VSMCs中p21和p57的蛋白水平随刺激时间进程增加，前者在第24小时达到峰值，且显著高于Ang II刺激的VSMCs。然而，静止细胞中p57蛋白水平较高。在PDGF-BB刺激的VSMCs中发现p57蛋白水平显著降低（P < 0.01）。
p27、p21和p57蛋白在调节VSMC的增生和肥大中起重要作用。P21和p57可防止VSMCs过度增生。P27是PDGF和Ang II刺激下VSMC增生和肥大的最重要调节因子。
