目的：观察体外模拟缺血／再灌注（ ischemia／reperfusion，I／R）微环境下人肺微血管内皮细胞（ hu-man pulmonary microvascular endothelial cells，HPMVECs）的自噬变化，研究自噬在维持I／R条件下HPMVECs细胞存活及内皮屏障完整性中的作用。方法：用雷帕霉素（ rapamycin，RAP）预处理HPMVECs，在缺糖缺氧／恢复糖和氧供（ oxygen-glucose deprivation／oxygen-glucose restoration，OGD）模拟的I／R微环境中孵育细胞。应用Western blot及透射电镜法检测细胞自噬变化，用流式细胞术检测细胞凋亡，通透性小室法检测HPMVECs通透性。结果：OGD条件下HPMVECs的自噬水平明显升高，RAP预处理进一步上调了OGD条件下的细胞自噬。 OGD组细胞凋亡率明显增高，细胞通透性增加。 RAP预处理不仅降低了OGD引起的细胞凋亡率，而且减轻了OGD条件下细胞通透性。结论：自噬在I／R诱发的肺微血管内皮细胞损伤中发挥保护性作用，提高自噬水平有助于减少I／R条件下细胞凋亡并维持内皮屏障完整性。%[ ABSTRACT ] AIM: To detect the autophagic changes of human pulmonary microvascular endothelial cells ( HPMVECs) under ischemia/reperfusion ( I/R) microenvironment, and to clarify the effects of autophagy on the HPM-VECs survival and endothelial barrier integrity under I/R condition.METHODS:Rapamycin ( RAP) was applied to pro-mote autophagy of HPMVECs.These cells were then incubated under the condition of oxygen-glucose deprivation/oxygen-glucose restoration ( OGD) .After exposure to OGD, the changes of autophagy, cellular death and permeability of the cells were determined by transmission electron microscopy, flow cytometry and transwell assay, respectively.RESULTS:Com-pared with the control cells, OGD-challenged cells had a much higher level of autophagy.The apoptotic rate was much higher and endothelial permeability was more serious in OGD group than those in control group.Preconditioning with RAP effectively improved OGD induced autophagy, it did not affect the cell survival and endothelial permeability under normal living condition, but obviously decreased the cells apoptotic rate, and remarkably lowered OGD-induced high permeability of the cells.CONCLUSION:Autophagy protects HPMVECs against I/R-induced injury.Promotion of autophagy is help-ful for attenuating I/R-induced cell death and sustaining the endothelial barrier integrity.
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