白蛋白联合低氧对NRK-52E细胞凋亡的影响

Effects of albumin and hypoxia on apoptosis of NRK-52E cells

目的:探讨白蛋白联合低氧对肾小管上皮细胞(NRK-52E)凋亡的影响。方法:应用流式细胞技术检测NRK-52E细胞在不同质量浓度白蛋白(0、10、20、30和40g/L)和常氧(含体积分数为5%CO2的空气)条件下培养24h的凋亡率,得到最适的白蛋白质量浓度;再应用流式细胞技术检测NRK-52E细胞在30g/L白蛋白和低氧(体积分数为1%O2、5%CO2和94%N2)联合培养24h的凋亡率,同时设常氧对照组、低氧对照组和常氧+30g/L白蛋白培养组。采用RT-PCR检测凋亡相关基因bcl-2和bax mRNA表达。结果:在常氧环境下NRK-52E细胞凋亡率随白蛋白质量浓度的增加而增高(F=55.748,P<0.001)。常氧对照组、低氧对照组和常氧+30g/L白蛋白培养组及低氧+30g/L白蛋白培养组NRK-52E细胞凋亡率(F=112.174,P<0.001)、bax mRNA(F=114.522,P<0.001)和bcl-2 mRNA(F=63.097,P<0.001)的表达差异均有统计学意义。低氧+30g/L白蛋白培养组的凋亡率[(37.36±4.95)%vs(25.59±3.32)%,P<0.05)和bax mRNA的表达(2.54±0.19vs1.87±0.19,P<0.05)高于常氧+30g/L白蛋白培养组,而bcl-2 mRNA的表达则低于常氧+30g/L白蛋白培养组[(0.42±0.08)vs(0.66±0.05)](P<0.05)。结论:低氧可加剧白蛋白诱导的NRK-52E细胞凋亡,其机制可能与促进bax mRNA高表达和bcl-2 mRNA低表达有关。

Aim：To explore the effects of albumin and hypoxia co-stimulus on the apoptosis of tubular epithelial cell NRK-52E.Methods：Rat NRK-52E cell apoptosis rate was measured by flow cytometry after incubation by different albumin concentration（0,10,20,30,40 g/L） in normoxia（5% CO2 /95% N2） for 24 h to obtain appropriate albumin concentration.NRK-52E cell apoptosis rate was measured by flow cytometry after incubation in hypoxia（1% O2 /5% CO2 /94% N2） and albumin（30 g/L） for 24 h.The expressions of bcl-2 and bax mRNA were detected by RT-PCR.Results：NRK-52E apoptosis rate increased with the increase of albumin concentration in normoxia（F = 55.748,P〈0.001）.There were significant differences in NRK-52E apoptosis rate（F = 112.174,P〈0.001）,bax mRNA（F = 114.522,P〈0.001） and bcl-2 mRNA（F =63.097,P〈0.001） expression among normoxia group,hypoxia group,normoxia ＋ albumin group and hypoxia ＋ albumin group;NRK-52E apoptosis rate and bax mRNA expression increased significantly,however,bcl-2 mRNA expression decreased significantly in hypoxia ＋ albumin group compared with that in normoxia ＋ albumin group.Conclusion：NRK-52E cells apoptosis induced by albumin is aggravated by hypoxia,and bax and bcl-2 mRNA expression imbalance might involve in the potential mechanism.