目的 研究大黄素诱导人肾小管上皮HK-2细胞凋亡的作用及其机制是否与内质网应激有关。方法 不同浓度大黄素处理HK-2细胞不同时间。MTT法检测细胞存活率，实时荧光定量PCR（RT-PCR）检测葡萄糖调节蛋白78（GRP78）、CCAAT/增强子结合蛋白同源蛋白（CHOP）、转录激活因子3（ATF3）和X盒结合蛋白1（XBP1）的基因表达，Western blotting法检测caspase-3、GRP78、CHOP、真核生物启动因子2α（eIF2α）的蛋白表达。结果 大黄素以浓度相关方式降低HK-2细胞存活率，诱导caspase-3剪切。RT-PCR检测表明，大黄素能诱导内质网相关基因GRP78、CHOP、ATF3基因表达，Western blottinh检测结果进一步证实大黄素能诱导GRP78、CHOP的蛋白表达。大黄素还明显诱导eIF2α磷酸化和XBP1 mRNA剪切。在大黄素给药之前给予内质网应激干扰药4-苯基丁酸和salubrinal，能增加HK-2细胞的存活率。结论 大黄素能诱导HK-2凋亡，内质网应激参与了大黄素诱导HK-2细胞凋亡的作用。

Objective To investigate the induetion of apoptosis in human renal tubular epithelial HK-2 cells by emodin and whether endoplasmic reticulum (ER) stress is involved in its mechanism. Methods HK-2 cells were cultured and treated with various concentration of emodin at different time points. The cell viability was determined by MTT assay. The gene expression of glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding protein-homologous protein (CHOP), activating transcription factor 3 (ATF3), and X-box binding protein 1 splicing (XBP1s) was evaluated by quantitative real-time PCR. The protein expression of caspase-3, GRP78, CHOP, and eukaryotic initiation factor 2 alpha (eIF2α) was detected by Western blotting. Results The viability of HK-2 cells was decreased by emodin in a dose-dependent manner, and the apoptosis of the cells was associated with caspase-3 shear activation. The treatment with emodin in HK-2 cells caused the increase in eIF2α phosphorylation, XBP1 mRNA splicing, the gene expression of GRP78, CHOP, and ATF3, and the protein expression of GRP78 and CHOP. The pretreatment with 4-phenylbutyric acid and salubrinal significantly increased the viability of HK-2 cells, indicating the role of ER stress in emodin-induced apoptosis. Conclusion Emodin induces the apoptosis in HK-2 cells and ER stress is involved in emodin-induced apoptosis.

国家自然科学基金资助项目（81102886）