恩格列净改善高糖诱导HK-2细胞凋亡的机制探讨

Mechanism of empagliflozin in mitigating HK-2 cells apoptosis induced by high glucose

目的探讨恩格列净改善人肾皮质近曲小管上皮细胞(HK-2细胞)凋亡的机制。方法将HK-2细胞置于正常葡萄糖、高葡萄糖、高葡萄糖+不同浓度的恩格列净共干预环境下培养48 h。采用蛋白免疫印迹法检测肾脏沉默信息调节因子2相关酶1(SIRT1)、硫氧还蛋白互作蛋白(TXNIP)以及裂解的半胱天冬酶-3(cleaved Caspase-3)的表达水平。采用TUNEL染色评估HK-2细胞凋亡情况。结果蛋白免疫印迹结果显示,高葡萄糖培养48 h后HK-2细胞的TXNIP和cleaved Caspase-3表达水平均高于正常葡萄糖组,而SIRT1表达水平低于正常葡萄糖组(P均<0.05)。1000 nmol/L恩格列净和30 mmol/L葡萄糖共干预48 h后,HK-2细胞的TXNIP和cleaved Caspase-3的蛋白表达水平降低,SIRT1表达水平升高(P均<0.001)。TUNEL染色结果显示恩格列净和30 mmol/L葡萄糖共干预组较30 mmol/L葡萄糖组TUNEL阳性细胞数少,且1000 nmol/L恩格列净和30 mmol/L葡萄糖共干预组凋亡改善更明显。结论恩格列净可能通过上调SIRT1的表达、抑制TXNIP表达,改善高糖诱导HK-2细胞凋亡。

Objective To investigate the mechanism of empagliflozin in mitigating the apoptosis of human renal proximal tubule epithelial cells(HK-2 cells).Methods HK-2 cells were incubated in normal glucose(NG)or high glucose(HG)combined without or with empagliflozin at different concentrations for 48 h.The expression levels of silent mating type information regulation 2 homolog 1(SIRT1),thioredoxin-interacting protein(TXNIP)and cleaved Caspase-3 were determined by Western blot.The apoptosis of HK-2 cells was determined by TUNEL staining.Results Western blot demonstrated that the expression levels of TXNIP and cleaved Caspase-3 at 48 h in the HG group were significantly higher,whereas that of SIRT1 was remarkably lower compared with those in the NG group(all P<0.05).After combined interventions of 1000 nmol/L empagliflozin and 30 mmol/L glucose for 48 h,the expression levels of TXNIP and cleaved Caspase-3 were significantly down-regulated,whereas that of SIRT1 was considerably up-regulated(all P<0.001).TUNEL staining demonstrated that the number of TUNEL-positive cells in the empagliflozin combined with 30 mmol/L glucose group was significantly less than that in the 30 mmol/L glucose group.In the 1000 nmol/L combined with 30 mmol/L glucose group,the cell apoptosis was more evident.Conclusion Empagliflozin can protect HK-2 cells from HG-mediated apoptosis probably by up-regulating the expression level of SIRT1 protein and down-regulating that of TXNIP protein.