硫化氢通过减轻肾小管上皮细胞凋亡改善糖尿病肾病

Hydrogen sulfide improves diabetic kidney disease by reducing apoptosis of renal tubular epithelial cells

目的研究H2S在糖尿病肾病中的作用及探讨其可能的机制。方法给予C57BL/6J小鼠STZ(50 mg/kg×4 d)腹腔注射和高脂饮食制备糖尿病模型,将造模成功小鼠分两组:STZ+GYY 4137组(H2S组)给予20 mg/kg GYY 4137腹腔注射,STZ+生理盐水组(DKD组)给予等量生理盐水腹腔注射。另外取正常C57BL/6J小鼠作为正常对照组,给予等量生理盐水腹腔注射。连续注射12周后,观察各组小鼠24 h尿白蛋白情况、肾组织形态学改变以及肾组织细胞凋亡情况。给予小鼠近端肾小管上皮细胞高糖(25 mmol/L)刺激并H2S预孵,观察细胞凋亡情况。结果DKD组小鼠24 h尿白蛋白较正常对照组增加,H2S治疗后小鼠尿白蛋白减少;DKD组小鼠肾小球系膜增殖,H2S治疗后小鼠肾小球系膜增殖改善;DKD组小鼠肾组织凋亡增加,H2S治疗后小鼠肾组织细胞凋亡减少;H2S产生酶胱硫醚β合成酶、胱硫醚β裂解酶、3-巯基丙酮酸转硫酶在肾脏表达,其中糖尿病小鼠仅胱硫醚β合成酶减少,胱硫醚β裂解酶、3-巯基丙酮酸转硫酶无改变。近端小管上皮细胞在高糖刺激下cleaved-caspase-3增加,H2S预孵降低cleaved-caspase-3的表达,改善细胞凋亡。结论H2S治疗能够降低糖尿病小鼠尿白蛋白,减轻肾小球系膜增殖,机制可能是通过降低caspase-3活性从而减轻高糖诱导的肾小管上皮细胞凋亡。

Objective To investigate whether GYY4137,a sustained-release agent of hydrogen sulfide,plays a protective role in diabetic kidney disease and its possible mechanism.Methods C57BL/6J mice were injected with STZ(50 mg/kg×4 d)intraperitoneally and high-fat diet to induce a diabetes kidney disease(DKD)model.The modeled mice were divided into two groups:STZ+GYY 4137 group(H2S group)administered intraperitoneally with 20 mg/kg GYY 4137,and STZ+physiological saline group(DKD group)administered intraperitoneally with the same amount of physiological saline.IN addition,normal C57BL/6J-1 mice were taken as the normal control group administered intraperitoneally with the same amount of physiological saline alone.After administering continuously for 12 weeks,24-hour urinary albumin,renal histomorphological changes and apoptosis of renal tissue cells in all the groups were observed.Hydrogen sulfide probes were used to detect the site of hydrogen sulfide production,and immunohistochemistry was used to detect the distribution of hydrogen sulfide-producing enzymes in the kidney.The proximal tubular epithelial cells were stimulated by high D-glucose(25 mmol/L)and incubated with hydrogen sulfide to observe the apoptosis.Results 24-hour urinary albumin was increased in the DKD group compared with the control group,and hydrogen sulfide treatment reduced urinary albumin in DKD mice.The glomerular mesangial cells proliferated in the DKD group,glomerular mesangial proliferation in diabetic mice was improved by hydrogen sulfide;renal tissue apoptosis cell increased in DKD mice,while that was alleviate by hydrogen sulfide.Hydrogen sulfide was mainly produced in renal tubules.Hydrogen sulfide producing enzymes:cystathionine β synthase(CBS),cystathionine β-lyase(CSE)and 3-mercaptopyruvate sulfurtransferase(MST)were all expressed in kidneys.CBS decreased in DKD mice,but CSE and MST did not change compared with normal mice.Cleaved-caspase 3 increased in proximal tubular epithelial cells stimulated by high glucose,and hydrogen sulfide pre-incubation decreased cleaved-caspase 3 expression and improved apoptosis.Conclusions Hydrogen sulfide treatment can reduce urinary albumin and mesangial proliferation in DKD mice,probably by reducing apoptosis of renal tubular epithelial cells induced by high glucose through decrease in caspase-3 activity.