基于TGF-β/Smads信号通路探讨苦参碱对糖尿病肾病小鼠的影响

Effect of matrine on diabetic nephropathy mices based on the TGF-β/Smads signaling pathway

目的研究苦参碱通过调控转化生长因子-β/信号传导蛋白(TGF-β/Smads)信号通路改善糖尿病肾病(DN)的作用及机制。方法将C57BL/6小鼠随机分为NC组、DN组、DN+苦参碱组和DN+二甲双胍组,每组10只。除NC组外,其余各组均用高脂高糖饮食加腹腔注射链脲佐菌素(STZ)的方法建立小鼠DN模型,造模成功后DN+苦参碱组灌胃给予苦参碱治疗4周,DN+二甲双胍组给予二甲双胍,DN组和NC组给予等量0.9%NaCl。用蛋白质印迹(Western blot)法检测小鼠肾组织中Ⅳ型胶原蛋白(ColⅣ)、纤连蛋白(FN)、Smad同源物2/3(Smad2/3)和磷酸化Smad2/3(p-Smad2/3)的表达水平;用生化法检测小鼠血糖、血肌酸酐和尿素氮水平。结果NC组、DN组和DN+苦参碱组小鼠血糖水平分别为(8.16±2.53)、(24.84±4.67)和(23.88±3.57)mmol·L^(-1);血肌酸酐水平分别为(36.48±5.63)、(97.51±10.59)和(41.88±7.26)mmol·L^(-1);尿素氮水平分别为(53.11±4.72)、(91.50±8.62)和(63.29±5.69)mmol·L^(-1);肾组织中ColⅣ蛋白的表达水平分别为1.00±0.19、3.34±0.58和1.99±0.44,FN蛋白的表达水平分别为1.00±0.21、3.63±0.47和1.79±0.43,p-Smad2/3/Smad2/3分别为1.00±0.18、2.74±0.51和1.08±0.33。上述指标,NC组与DN组相比,在统计学上差异均有统计学意义(均P<0.05)。结论苦参碱能够有效抑制TGF-β/Smads信号通路的激活,减少细胞外基质相关蛋白的聚积,从而发挥保护DN肾损伤的作用。

Objective To investigate the effect of matrine on improving diabetic nephropathy(DN)through transforming growth factorβ/signal transduction protein(TGF-β/Smads)pathway.Methods C57BL/6mice were randomly divided into NC group,DN group,DN+matrine group,and DN+metformin group,with 10 mice in each group.Except for NC group,other groups were established DN models by high-fat and high-sugar diet combined with intraperitoneal injection of streptozotocin(STZ).After successful modeling,DN+matrine group was treated with matrine for 4 weeks,DN+metformin group was treated with metformin,DN and NC groups were given equal volumes of 0.9%NaCl.Western blot was used to detect the expression of collagenⅣ(ColⅣ),fibronectin(FN),Smad family member 2/3(Smad2/3),and phosphorylated Smad2/3(p-Smad2/3)in kidney.Biochemical method were used to detect blood glucose,creatinine,and urea nitrogen levels of mice.Results In NC group,DN group and DN+matrine group,blood glucose levels were(8.16±2.53),(24.84±4.67)and(23.88±3.57)mmol·L^(-1);blood creatinine levels were(36.48±5.63),(97.51±10.59)and(41.88±7.26)mmol·L^(-1);urea nitrogen levels were(53.11±4.72),(91.50±8.62)and(63.29±5.69)mmol·L^(-1);ColⅣprotein expression levels in kidney were 1.00±0.19,3.34±0.58 and 1.99±0.44;FN protein expression levels were 1.00±0.21,3.63±0.47 and 1.79±0.43;p-Smad2/3/Smad2/3 were 1.00±0.18,2.74±0.51 and 1.08±0.33.Above indicators showed statistically significant differences between NC group and DN group(all P<0.05).Conclusion Matrine can effectively inhibit the activation of TGF-β1/Smads signaling pathway and reduce the polyproduct of extracellular matrix-related proteins,thus playing a protective role in DN kidney injury.