Omi/HtrA2在缺氧复氧后人近曲肾小管上皮细胞中的表达及促红细胞生成素对其表达的影响

Expression of Omi/HtrA2 in Human Renal Proximal Tubular Epithelial Cells with Hypoxia/Reoxygenation and Effect of Erythropoietin on It

目的探讨缺氧复氧(H/R)后人近曲肾小管上皮细胞内Omi/HtrA2的表达变化及促红细胞生成素(EPO)干预的影响。方法以人近曲肾小管上皮细胞株(HK-2细胞)为研究对象,将其分为对照组、H/R组及EPO干预组。对照组常规培养;H/R组缺氧24 h后复氧6 h;EPO干预组在H/R前加入5 000 U.L-1EPO预处理。倒置显微镜观察细胞形态,四甲基偶氮唑蓝(MTT)法检测细胞活力,流式细胞仪检测细胞凋亡,免疫组织化学检测细胞内Omi/HtrA2表达变化。结果与对照组比较,H/R组细胞数量减少,细胞形态发生改变,细胞活力下降,细胞凋亡率显著增加,细胞内Omi/HtrA2表达增强,差异均有统计学意义(Pa<0.05);而与H/R组相比,EPO干预组细胞数量增多,细胞形态明显改善,细胞活力增加,细胞凋亡率下降,Omi/HtrA2表达减弱,差异均有统计学意义(Pa<0.05),但各指标均未恢复至对照组水平。结论 H/R可通过上调Omi/HtrA2表达而促进肾小管上皮细胞凋亡,EPO对H/R肾小管上皮细胞具有保护作用,其机制可能与抑制Omi/HtrA2表达、减少细胞凋亡有关。

Objective To investigate the expression of Omi/HtrA2 in renal tubular epithelial cells with hypoxia /reoxygenation（H/R） and to evaluate the effect of erythropoietin（EPO） on it. Methods Human renal proximal tubular epithelial cell line HK-2 cell was used as target cell.The cultural cells in orifice were divided into the following groups：control group,H/R group and EPO group.The cells of control group were cultivated with normal nutritive medium;the cells of the H/R group were exposed to hypoxia for 24 h,then to normoxia for 6 h;and the cells of EPO group were added 5 000 U·L-1 EPO before H/R.The change of morphology was observed under inverted microscope,the cell viability was measured by 3-（4,5）-dimethylthiahiazo（-z-y1）-3,5-di-phenytetrazoliumromide（MTT） method.The rate of apoptosis cells was detected by flow cytometry,the expression of Omi/HtrA2 in cytoplast was detected by the immunohistochemical method. Results Compared with the control group,the change in morphology of HK-2 was most serious and obvious,and the viability decreased obviously,the apoptosis rate of cells was obviously increased and the expression of Omi/HtrA2 was significantly increased in H/R group,and the differences were significant（Pa〈0.05）.But compared with H/R group,the change in morphology of HK-2 was obviously improved,and the cell viability increased,the apoptosis rate of cells and the expression of Omi/HtrA2 was significantly decreased in EPO group,and the diffe-rences were significant（Pa〈0.05）,but all parameters were not restored to the level of control group. Conclusions The expression of Omi/HtrA2 in HK-2 cell might be induced by H/R,Omi/HtrA2 might play an important role in the course of HK-2 cell apoptosis induced by H/R and EPO can reduce these injures.