小分子活性肽apelin在低氧诱导肺血管内皮细胞损伤中的表达及其意义

Expression of apelin on PVECs injury induced by hypoxia and its significance

目的:探讨apelin-APJ系统在低氧诱导肺血管内皮细胞(PVECs)损伤中的表达变化,阐明小分子活性肽apelin对细胞增殖的影响。方法:体外培养的大鼠PVECs分为正常对照组、低氧6h组、低氧12h组、低氧24h组、低氧48h组、低氧24h加apelin组和apelin组,MTT法检测各组细胞增殖率。体外培养的大鼠PVECs分为正常对照组和低氧6h组、12h组及24h组,免疫荧光染色法检测细胞中apelin蛋白荧光表达,Western blotting法检测apelin-APJ系统蛋白表达水平。结果:与正常对照组比较,低氧6、12h组和apelin组细胞增殖率无明显变化(P>0.05),低氧24和48h组细胞增殖率明显降低(P<0.05或P<0.01);与低氧24和48h组比较,低氧24h加apelin组细胞增殖率明显升高(P<0.05)。与正常对照组比较,低氧6h组细胞中apelin荧光表达强度无明显变化(P>0.05),低氧12和24h组细胞中apelin荧光表达强度明显降低(P<0.01)。与正常对照组比较,低氧6、12和24h组细胞中apelin蛋白表达水平明显下降(P<0.01),而APJ蛋白表达水平无明显变化(P>0.05)。结论:低氧可能通过降低小分子活性肽apelin损伤内皮细胞,而外源性给予apelin在一定程度上能够保护低氧对肺血管内皮细胞的损伤作用。

Objective To investigate the changes of the expression of apelin-APJ system in the injury of pulmonary vascular endothelial cells（PVECs）under hypoxia conditions,and to clarify the role of apelin in the cell proliferation.Methods The in vitro cultured rat PVECs were divided into control group,hypoxia 6hgroup,hypoxia 12 hgroup,hypoxia 24 hgroup,hypoxia 48 hgroup,hypoxia 24h＋apelin group and apelin group.The proliferation rates of PVECs in every group were detected by MTT assay.The in vitro cultured rat PVECs were divided into normal control group,hypoxia 6hgroup,hypaxia 12 hgroup and hypoxia 24 hgroup.The expression of apelin in the cells were observed by immunofluorescence staining.The expression levels of apelin-APJ protein were measured by Western blotting method.Results Compared with normal control group,the proliferation rates of the PVECs in hypoxia 6h,12 hgroups and apelin group had no change（P〉0.05）,but the proliferation rates of the PVECs in hypoxia 24 hand 48hgroups were decreased significantly（P〈0.05 or P〈0.01）.Compared with normal control group,the immunofluorescence expression of apelin in the PVECs in hypoxia 6hgroup had no obvious change（P〉0.05）,but the expression of apelin in the PVECs in hypoxia 12 hand 24hgroups were decreased（P〈0.01）.Compared with normal control group,the expression levels of apelin protein in the PVECs in hypoxia 6h,24 hand 48hgroups were decreased（P〈0.01）,but the protein expression of APJ in the PVECs had no significant changes（P〈0.05）.Conclusion Hypoxia may injury the PVECs through inhibiting the apelin expression,and exogenous apelin can protect the injure of PVECs induced by hypoxia.