DPP-4抑制剂沙格列汀对2型糖尿病大鼠肾损伤的保护作用

Effects of the DPP-4 inhibitor Saxagliptin against kidney injury in type 2 diabetes mellitus rats

关键词:  DPP-4抑制剂  沙格列汀  2型糖尿病肾病  肾损伤  免疫调节

Key words:  DPP-4 inhibitor  Saxagliptin  type 2 diabetes mellitus  kidney injury  immune function

摘要:

目的　研究二肽基肽酶4（DPP-4）抑制剂沙格列汀对2型糖尿病大鼠肾脏损伤的保护作用并探讨其作用机制。 方法　将30只雄性SD大鼠，随机分成3组（每组10只）：正常对照组（NC组）、2型糖尿病模型组（T2DM组）、模型+沙格列汀1.0 mg/kg治疗组（Sax组）。NC组大鼠饲以普通饲料；T2DM组及Sax组大鼠以高脂饮食联合链脲佐菌素（STZ）造2型糖尿病大鼠模型；Sax组大鼠每日1次灌胃给予沙格列汀1.0 mg/kg，NC组和T2DM组灌胃给予等容量生理盐水，连续给药12周后实验终止。记录大鼠体重，测定24 h摄食量、饮水量和24 h尿量；检测空腹血糖（GLU），血清中总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）、高密度脂蛋白（HDL）、血肌酐（Cr）和血尿素氮（BUN）水平；采用流式细胞术检测外周血T淋巴细胞亚群水平；取肾脏组织行HE染色观察肾组织病理学变化，免疫组化检测肾组织转化生长因子β（TFG-β）的表达水平；Western blot检测肾组织NF-κB p65、COX-2的蛋白表达水平，RT-PCR检测TNF-α、IL-6、FoxO1的mRNA表达水平。 结果　Sax组与T2DM组大鼠相比，GLU、TG、TC和LDL水平明显降低（P<0.05），HDL水平明显升高（P<0.05）；大鼠饮水量、体重明显降低（P<0.05）； Sax组较T2DM模型组大鼠肾小球肿胀、炎性浸润现象明显缓解，TFG-β表达水平降低（P<0.05）；外周血T淋巴细胞亚群水平的失衡明显改善（P<0.05）；下调炎症相关因子TNF-α、IL-6、FoxO1的mRNA表达水平及NF-κB p65、COX-2的蛋白表达水平（P<0.05）。 结论　DPP-4抑制剂沙格列汀具有保护大鼠2型糖尿病肾损害作用，其作用机制可能为抑制炎症的发生及参与免疫调节。

Abstract:

Objective To investigate the effects of Saxagliptin, a DPP-4 inhibitor, against kidney injury in type 2 diabetes mellitus rats. Methods Thirty male Sprague-Dawley rats were divided into 3 groups randomly (n=10): control group, type 2 diabetes mellitus (T2DM) group, T2DM+Saxagliptin 1.0 mg/kg (Sax) group. The rats of T2DM group and Sax group were fed with a high-fat diet and given STZ to establish experimental type 2 diabetes model, while the rats of control group were fed with a normal diet. The rats of Sax group were administered Saxagliptin 1.0 mg/kg once a day for 12 weeks and the rats of control group and T2DM group were given equal volume of saline. Blood glucose was measured in a blood glucose meter. TC, TG, LDL, HDL, Cr, BUN were measured in a blood automatic analyzer. The level of Tregs were measured by flow cytometry. Kidney tissues were examined with HE staining. TFG-β expression was detected by immunohistochemistry. The expression level of TNF-α, IL-6, FoxO1, NF-κB p65, COX-2 were determined by western blotting and Real-time PCR. Results Saxagliptin decreased blood glucose, reduced food/water intakes and body weight, decreased serum lipid parameters (TC, TG, LDL), ameliorated Cr, BUN, INF-γ/IL-10, Tregs levels. Saxagliptin significantly down-regulated the expressions of TFG-β, TNF-α, IL-6, FoxO1, NF-κB p65, COX-2. Conclusion DPP-4 inhibitor Saxagliptin could lessen kidney injury in type 2 diabetes mellitus rats by inhibiting inflammation and regulating immune function.