回转模拟失重对静脉内皮细胞血管生成能力的影响及内皮型一氧化氮合成酶的作用

Effects of Clinostat Rotation on Vein Endothelial Cell Angiogenesis and Role of Endothelial Nitric Oxide Synthetase

目的 观察回转器模拟失重对人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC-C)血管生成能力的影响,并分析探讨可能涉及的关键信号分子内皮型一氧化氮合成酶(endothelial nitricoxide synthetase,eNOS)的作用。方法体外培养HUVEC-C,随机分为回转模拟失重组、1 G静止对照组及回转+抑制剂组,选用内皮型一氧化氮合成酶的特异性抑制剂L-NAME(N-nitro-L-arginine methyl es-ter hydrochloride)。Matrigel胶小管形成实验观察不同处理组HUVEC-C血管生成能力的变化情况。RT-PCR和Western blot分别检测模拟失重前、后HUVEC-C中eNOS mRNA和蛋白的表达变化。结果24 h模拟失重使HUVEC-C的血管生成能力较对照组明显增强(P<0.01),且这种增强效应可以被L-NAME所抑制。模拟失重24 h后,HUVEC-C中eNOS mRNA和蛋白的表达均显著高于对照组(P<0.05)。结论回转模拟失重可以诱导HUVEC-C血管生成能力增强,其发生机制与eNOS表达上调有关。

Objective To investigate the effects of clinostat rotation on human umbilical vein endothelial cells （HUVEC-C） angiogenesis and the role of endothelial nitric oxide synthetase （eNOS）. Methods HUVEC-C cultured in vitro were randomly divided into three groups： cells exposed to normal gravity for 24 h （Con）, simulated microgravity for 24 h （Clino） and simulated microgravity co-cultured with N-nitro-L-arginine methyl ester hydrochloride（ L-NAME）, the pharmacological inhibitor of eNOS （Clino ＋ L-NAME）. The tube forma- tion assay was performed to evaluate the effects of clinostat rotation on HUVEC-C angiogenesis. Moreover, the expression of eNOS was detected by RT-PCR and Western blot in both Clino and Con groups. Results After 24 h of exposure to simulated microgravity, HUVEC-C tube formation was significantly promoted in comparison with Con groups （P 〈0.01）. And it could be reversed by co-incubation with L-NAME. The mRNA level of eNOS after clinostat rotation was obviously higher than that of Con （P 〈 0.05 ）. eNOS protein expression in cli- nostat rotation group also showed a dramatic increase compared with that in Con（P 〈0.05 ）. Conclusion The promotion of angiogenesis induced by simulated microgravity in HUVEC-C is correlated with eNOS expression. Key words： simulated weightlessness ; clinostat ; endothelial cells ; angiogenesis ; eNOS