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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。
Objective To investigate the effects of PI3K-p70S6K and Ras-p42 / p44MAPK signaling pathway on the proliferation and cell cycle progression of human umbilical vein endothelial cells (HUVECs) induced by angiotensin Ⅱ (ANGⅡ). Methods ANGⅡ combined with different concentrations of rapamycin to stimulate HUVEC cultured in vitro, 3H-thymidine incorporation and 3H-leucine incorporation assay of DNA and protein synthesis, flow cytometry to detect cell cycle changes, immune Western blot was used to detect the expression of p70S6K, extracellular signal regulated kinase (ERK2) and cyclinD1, CyclinA and CyclinBt. Results Rapamycin could inhibit angiotensin II-induced protein synthesis and DNA synthesis in a dose-dependent manner. Rapamycin could inhibit the expression of p70S6K and CyclinD1 induced by ANGⅡ, arresting cells in G1 phase (P <0.01) ), Without affecting the expression of ERK2, CyclinA and CyclinBt. Conclusion The PI3K-p70S6K signaling pathway plays a key role in ANGⅡ-induced HUVEC proliferation and cell cycle progression. Rapamycin immunosuppressive target p70S6K can be used to interfere with the proliferation of vascular endothelial cells.