目的 观察7,8-二羟基黄酮（7,8-DHF）对缺氧诱导的人近端肾小管上皮细胞内质网应激（ERS）损伤的影响，并探讨其可能的分子机制。 方法 体外培养人近端肾小管上皮细胞（HK-2），采用缺氧培养箱建立细胞缺氧损伤模型，排除含血清培养基对缺氧的影响后，实验分为5组，分别为缺氧0 h、4 h、8 h、12 h 、16 h组。实时荧光定量PCR（RT-PCR）法筛选缺氧诱导ERS的最佳缺氧时间。用不同浓度（50、100、150、200、250 μmol/L）7,8-DHF处理HK-2细胞, 采用细胞增殖与活性实验筛选7,8-DHF 的安全浓度。用7,8-DHF预处理HK-2细胞缺氧模型，按以下处理因素分组：对照组、缺氧+DMSO组、缺氧+7,8-DHF组（包括100 μmol/L组和150 μmol/L组），通过检测细胞增殖与活性筛选最佳给药浓度。后将细胞随机分为缺氧组、缺氧+7,8-DHF组（100 μmol/L），Western印迹法检测细胞蛋白激酶（Akt）、磷酸化蛋白激酶 （p-Akt）、富含半胱氨酸蛋白61（Cyr61）、ERS相关促凋亡蛋白CCAAT增强子结合蛋白（CHOP）的表达。用重组Cyr61慢病毒载体构建稳定表达Cyr61蛋白的Cyr61-HK-2细胞株进行缺氧实验，按如下处理因素分组：缺氧+空质粒转染组，缺氧+Cyr61过表达组，膜连蛋白V和碘化丙啶（Annexin V-FITC/PI）染色后，采用流式细胞仪检测细胞凋亡，Western印迹法检测Cyr61和CHOP蛋白的表达情况。 结果 （1）与对照组细胞相比，RT-PCR实验结果显示12 h为诱导ERS的最佳缺氧时间（P＜0.01）。（2）与对照组相比，细胞增殖与活性实验结果显示100 μmol/L的7,8-DHF组为最佳给药浓度（P＜0.01）。（3）与缺氧+DMSO组相比，缺氧+7,8-DHF细胞 p-Akt、Cyr61表达量均明显增加，CHOP表达量明显降低（均P＜0.05）；LY294002处理可抑制 p-Akt的表达，减少Cyr61及增加CHOP的表达（均P＜0.05）。（4）与缺氧+空质粒转染组相比，过表达Cyr61组细胞的凋亡率明显降低；Cyr61表达量明显增加， CHOP表达量明显降低（P＜0.01）。 结论 缺氧可诱导HK-2细胞发生ERS，7,8-DHF可能通过激活Akt通路上调Cyr61，阻止ERS下游凋亡蛋白CHOP的活化，抑制细胞凋亡以及减轻缺氧诱导的HK-2细胞损伤，提示7,8-DHF可能对AKI发挥保护作用。

Objective To observe the effects of 7,8-dihydroxyflavone (7,8-DHF) on hypoxia induced endoplasmic reticulum stress (ERS) in human proximal tubular epithelial cells (HK-2). Methods The mRNA level of ERS associated biomarkers was evaluated by RT-PCR assay in cell hypoxia damaged model. And HK-2 cells were pretreated with different concentrations of 7,8-DHF through CCK-8 assay; meanwhile CCAAT/enhancer-binding protein homologous protein (CHOP), Cyr61, Akt and p-Akt were determined by western blotting assay. Moreover, HK-2 cells were pretreated by LY294002, a kind of PI3K/Akt inhibitor, to inhibit the PI3K/Akt signaling, and its effects on protein level induced by 7,8-DHF was detected. HK-2 cells was then over-expressed Cyr61 and exposed to hypoxia Apoptosis rate and CHOP expression were determined. Results Compared to hypoxia group (P＜0.01), Hypoxia for 12h was effective in inducing ERS (P＜0.01), while pretreatment with 7,8-DHF (100 μmol/L) increased cell proliferation significantly . The protein expressions of Cyr61 and p-Akt in H+7,8-DHF group were higher, but the level of CHOP was decreased (P＜0.05). With LY294002 pretreated, the expression of Cyr61, p-Akt was down-regulated (all P＜0.05) while the expression of CHOP was up-regulated (P＜0.05). In comparison to empty plasmid group, when cells were transfected with over-expression of Cyr61 plasmid and exposed to hypoxia, the number of apoptotic tubular cells was decreased (P＜0.01). And over-expression of Cyr61 significantly reduced CHOP expression compared with the empty plasmid group (P＜0.01). Conclusion Pretreatment of 7,8-DHF could protect cells from hypoxia injury and inhibit ERS, which may involve the Akt-Cyr61 signaling pathway.