氧化应激对大鼠肾小管上皮细胞生物学行为的影响及L-EGCG的保护作用

Influence of Oxidative Stress on the Biological Behaviors of Renal Tubular Epithelial Cells and Therapeutic Potential of EGCG

[目的]探讨氧化应激对大鼠肾小管上皮细胞（NRK）生物学行为的影响及L -表没食子儿茶素没食子酸酯（L -EGCG）对NRK细胞氧化性损伤的保护作用.[方法]利用H2O2刺激离体培养的NRK细胞建立氧化损伤的模型,筛选H2O2对NRK细胞损伤研究的最适剂量与最佳时点.然后将培养细胞分EGCG正常对照组、H2O2组、不同浓度儿茶素组.MTT法检测细胞活力,流式细胞仪测定细胞凋亡,荧光探针JC-1测定线粒体膜电位.利用生物化学法检测各组NRK细胞培养上清中丙二醛（MDA）含量及乳酸脱氢酶（LDH）漏出量.[结果]①250 μmol/L H2O2作用6 h剂量组即可引起NRK细胞损伤;②L-EGCG能明显改善H2O2导致的细胞损伤,可使细胞存活率升高,LDH释放量降低,MDA生成减少,稳定了线粒体膜电位,减轻了细胞凋亡.[结论]氧化应激能导致大鼠肾小管上皮细胞活力下降,凋亡增加,L-EGCG可能是通过提高NRK细胞的抗氧化能力而提高其对H2O2损伤的保护及损伤修复能力.

[Objective] To explore the effect of oxidative stress on the biological behaviors of renal tubular epithelial cells（NRK52E） and the effect of L epigallo catechin gallate（L-EGCG） for protecting the oxidative injury of NRK cells. [Methods] The experimental model in H2O2-induced renal epithelial cell iniury was established. The optimum dose and best time point of NRK injury induced by H2O2 were screened. The cultured cells were divided into EGCG normal control group, H2O2 group and different concentration of catechin group. MTT method was used to detect the activity of the cell, and flow cytometry was used to measure the cell apoptosis, and fluorescent probe was used to determine the mitochondrial membrane potential（MMP）. The content of malondialdehyde （MDA） and lactated dehydrogenase （LDH） leakage in NRK cell culture supernatant in groups were detected by biochemical assay＇. [Results] NRK could be injured by 250μmol/L H2O2 for 6 hours. L-EGCG could improve significantly the cell damage induced by H2O2, and increase the cell survival rate, and decrease the releasing of LDH and the production of MDA. L-EGCG could also alleviate lipid peroxidation, and stabilize MMP, and inhibit cell apoptosis. [Conclusion] Oxidative stress can result in the decrease of the activity of renal tubular epithelial cell and the increase of apoptosis. L-EGCG may improve the ability to pro- tect and repair the H2O2-incuced injury through increasing the antioxidant capacity of NRK cells.