金葡菌及其L型诱导脐静脉内皮细胞凋亡及相关基因的研究

目的:探讨金黄色葡萄球菌(金葡菌)及其L型诱导细胞凋亡的作用及可能的分子机制.方法:用流式细胞术检测金葡菌及其L型感染人脐静脉内皮细胞(HUVECs) 后2 h、4 h、6 h、8 h和10 h的细胞凋亡率,并同时用免疫组化方法检测各时间点bcl-2及Fas基因的表达情况. 结果:金葡菌及其L型均能诱导HUVECs发生凋亡,与对照组比较差异有显著性(P<0.05～P<0.01).金葡菌L型诱导细胞的凋亡率均低于金葡菌(P<0.01);bcl-2及Fas基因表达率在感染后6 h与对照组比较差异均有显著性(P<0.01),在诱导的时间内bcl-2基因表达率逐渐降低,而Fas基因表达率逐渐增加(P<0.01).结论:金葡菌及其L型均能诱导HUVEC发生凋亡,其机制可能与下调bcl-2蛋白及上调Fas蛋白有关.

Study on apoptosis and expression of its related genes of umbilical vein endothelial cells induced by S.aureus and its L-forms

Objective:To investigate the possible mechanism of apoptosis of human umbilical vein endothelial cells(HUVECs) induced by Staphylococcus aureus(S.aureus) and its L-forms.Methods:S.aureus and its L-forms were used to infect HUVECs by incubation for different intervals of 2 hours,4 hours,6 hours,8 hours and 10 hours.Apoptotic rates in the treated cells were measured by flow cytometry,and expression of bcl-2 and Fas gene were detected by using immunohistochemical staining.Results:Both S.aureus and its L-forms induced apoptosis in HUVECs.The apoptotic rates of treated HUVECs at different time were significantly higher than that of the control (P<0.05-P<0.01).Morever the apoptotic rates induced by L-forms were obviously lower than that by S.aureus(P<0.01).At the 6 hours after infection,Bcl-2 expression in HUVECs teated with S.aureus and its L-forms was significantly lower,but that of Fas significantly higher than that in the control group.Conclusions:Both S.aureus and its L-forms can induce apoptosis of HUVECs which may be resulted from bcl-2 down-regulation and Fas up-regulation.