西格列汀对1型糖尿病小鼠肾病的干预作用

Intervention effect of sitagliptin on diabetic nephropathy in type 1 diabetic mice

目的研究西格列汀对1型糖尿病(T1DM)留取尿样以测定24 h尿微量白蛋白(ALB)含量,小鼠肾损伤的影响及机制。方法造模组小鼠一次腹腔注射链脲佐菌素(150 mg·kg^(-1))诱导糖尿病模型。成模后小鼠(血糖≥16.7mmol·L^(-1))按照血糖值随机分为2组:模型组和实验组。实验组给予西格列汀15 mg·kg^(-1)·d^(-1),模型组和正常组给予等体积的超纯水。给药4周后,留取血清检测尿素氮(BUN)和肌酸酐(SCr)。用免疫印迹法检测肾组织转化生长因子-β_1(TGF-β_1)、信号传导蛋白(Smad 2、Smad3)的表达。结果给药4周后,模型组与实验组的ALB分别为(11.96±3.36)(2.46±0.97)mg/24 h,与模型组比较差异有统计学意义(P<0.001)。正常组、模型组与实验组的肾指数分别为15.20±2.24,21.43±2.16,15.14±4.14,与正常组比较,模型组差异有统计学意义(P<0.05);与模型组比较,实验组差异有统计学意义(P<0.05)。模型组与实验组的SCr分别为(352.58±47.09),(238.51±53.03)μmol·L^(-1);这2组的BUN分别为(26.08±4.65),(10.40±2.47)mmol·L^(-1),与模型组比较,差异均有统计学意义(P<0.01,P<0.001)。正常组肾组织的TGF-β_1、Smad2/3及p-Smad2/3蛋白表达水平分别为0.19±0.02,0.12±0.02,0.07±0.01,模型组小鼠肾组织中蛋白表达水平分别为0.23±0.02,0.27±0.04,0.13±0.01,组间比较差异均有统计学意义(P<0.05,P<0.01)。与模型组比较,实验组小鼠肾组织蛋白表达水平分别为0.18±0.01,0.14±0.01,0.11±0.00,组间比较差异均有统计学意义(P<0.05,P<0.01)。结论西格列汀在不降低血糖的情况下,延缓T1DM肾病的进展,可能部分是通过抑制TGF-β_1/Smad2/3信号通路实现的。

Objective To explore the intervention effect and mechanism of sitagliptin on renal injury in type 1 diabetic（T1DM） mice.Methods The modeling group was intraperitoneally injected with streptozotocin（150 mg · kg-1） once and blood glucose ≥ 16.7 mmol·L-1 was considered as diabetes mellitus（DM）.DM mice were randomly divided into two groups： model group and experimental group.Experimental group was treated with sitagliptin（15 mg·kg-1·d-1） via intragastric administration for 4 weeks while the mice in model group and normal group treated with equal volume of ultrapure water.The 24 h microalbuminuria（ALB） was determined after administration.At the end of the experiment,urea nitrogen（BUN） and creatinine（SCr） in serum was detected.The protein expression levels of transforming growth factor-β1（TGF-β1）,Smad2,Smad3 were measured by Western blot.Results After administration sitagliptin for 4 weeks,the contents of ALB in model group and experimental group were（11.96 ±3.36）（2.46 ±0.97） mg/24 h with significantly（P 〈0.001）.The index of kidney weight/body weight（KW/BW） in normal group,model group and experimental group were 15.20 ± 2.24,21.43 ± 2.16,15.14 ± 4.14; compared with normal group,the difference was significantly increased（P 〈 0.05）; compared with model group,the difference was significantly increased（P 〈 0.05）.The SCr in model group and experimental group were（352.58 ± 47.09）,（238.51 ± 53.03）μmol·L-1; the BUN in the two groups were（26.08 ±4.65）,（10.40 ±2.47） mmol·L-1; compared with model group,the difference was significantly increased（P 〈 0.01,P 〈 0.001）.The expression levels of TGF-β1,Smad2/3 and p-Smad2/3 in normal group,model group and experimental group were 0.19 ± 0.02,0.12 ± 0.02,0.07 ± 0.01; 0.23 ± 0.02,0.27 ± 0.04,0.13 ± 0.01; 0.18 ± 0.01,0.14 ± 0.01,0.11 ± 0.00,compared with normal group,the difference was significantly increased（P 〈 0.05,P 〈0.01）; compared with model group,the difference was significantly increased（P 〈 0.05,P 〈 0.01）.Conclusion Experimental delaying the progression of T1DM nephropathy without not decreasing blood glucose can effect partly through inhibiting TGF-β1/Smad2/3 pathway.