雷帕霉素抑制血管紧张素Ⅱ诱导的血管内皮细胞增生(英文)

Inhibition by rapamycin on proliferation of vascular endothelial cells induced by angiotensinⅡ

目的研究阻断PI3K-p70S6K和Ras-p42／p44MAPK信号通路对血管紧张素Ⅱ(ANGⅡ)诱导的脐静脉内皮细胞(HUVEC)增殖及细胞周期进程的影响。方法ANGⅡ联合不同浓度雷帕霉素刺激体外培养的HUVEC,3H-胸腺嘧啶核苷掺入法和3H-亮氨酸掺入法测定细胞DNA和蛋白质合成,流式细胞术检测细胞周期变化,免疫印迹(Western blot)检测细胞信号蛋白p70S6K (p70 ribosomal protein S6 kinase),ERK2(extracellular signal regulated kinase)及细胞周期蛋白CyclinD1、CyclinA、和CyclinBt表达的变化。结果雷帕霉素抑制ANGⅡ诱导的血管内皮细胞蛋白质和DNA的合成,并呈剂量依赖性,雷帕霉素抑制ANGⅡ诱导的p70S6K和CyclinD1的表达,阻滞细胞于G1期(P<0．01),而不影响ERK2、CyclinA和CyclinBt的表达。结论PI3K-p70S6K信号通路在ANGⅡ诱导的HUVEC增殖及细胞周期进程中起关键作用,雷帕霉素免疫抑制靶点p70S6K可应用于干预血管内皮细胞的增殖。

AIM To investigate the effect of rapamycin on proliferation and cell cycle progression of human umbilical vein endothelial cells（HUVEC） induced by angiotensin Ⅱ （ANG Ⅱ ） in vitro through inhibition of the PI3K-pTOS6K cascade and the Ras-p42/p44^MAPK cascade. METHODS Cultured HUVEC were stimulated by ANG Ⅱ alone or in combination with different concentrations of rapamycin. The cell proliferation was measured by incorporation of ^3H-thymidine and ^3H-leucinne. Cell cycle was analysed by flow cytometry. Expression of pTOS6K, ERK2, cyclinA, cyclinBl and cyclinD1 were detected by Western blots. RESULTS Rapamycin inhibited ANG Ⅱ -induced increase in protein content and DNA synthesis dose dependently. Rapamycin inhibited the expression of p70S6K and cyclinD1, but inducing G1 cell cycle arrest （ P 〈 0.01） without affecting the expression of ERK2, cyclinA and cyclinB1. CONCLUSION p70S6K signaling appears to be important for G1-S phase progression and proliferation in ANG Ⅱ -induced HUVEC. Rapamycin targeted pTOS6K could have great potential in therapeutic intervention in the proliferation of vascular endothelial cells.