积雪排毒汤1号对糖尿病肾病小鼠肾损伤的保护作用及机制

Protective Effects of Jixuepaidu Tang-1 on Renal Injury of Mice with Diabetic Nephropathy

目的观察积雪排毒汤1号对链脲佐菌素(streptozotocin,STZ)诱导的糖尿病肾病(diabetic nephropathy,DN)小鼠肾损伤的保护作用及机制。方法 SPF级8周龄C57BL/6j雄性小鼠腹腔注射STZ诱导糖尿病肾病小鼠模型,随后分为正常组、模型组、蒙诺组、积雪排毒汤1号高剂量组及其低剂量组,每组8只。造模成功后2周开始干预,分别处理4周后检测小鼠体重、肾重、肾重指数、血糖、血清肌酐和24h尿蛋白定量。取肾脏组织进行PAS染色,光镜下观察肾小球系膜区细胞外基质积聚,用Western blot检测各组小鼠肾皮质中α-SMA、FN、Nephrin和P-cadherin蛋白的表达,透射电镜观察肾小球超微病理结构并测量肾小球基底膜厚度。结果与正常组比较,模型组、蒙诺组、积雪排毒汤1号高剂量组及低剂量组小鼠体重、肾皮质中Nephrin、P-cadherin蛋白的表达均显著降低(均P<0.05),肾小球系膜区细胞外基质、肾重指数、血糖、24h尿蛋白定量和肾皮质中α-SMA、FN蛋白表达均显著增高(均P<0.05);与模型组比较,蒙诺组、积雪排毒汤1号高剂量组及低剂量组小鼠肾皮质中Nephrin、P-cadherin蛋白的表达均显著增高(均P<0.05),而肾重指数、24h尿蛋白定量、肾小球系膜区细胞外基质积聚和肾皮质中α-SMA、FN蛋白表达均显著降低(均P<0.05);与模型组及蒙诺组相比较,积雪排毒汤1号高剂量组及低剂量组小鼠肾小球基底膜厚度均显著变薄(均P<0.05)。结论积雪排毒汤1号能够抑制DN小鼠肾小球系膜区细胞外基质积聚、减少肾重指数、减少24h尿蛋白、抑制DN小鼠肾小球基底膜的增厚及足突细胞损伤,其机制可能与抑制糖尿病肾病小鼠肾皮质中α-SMA、FN过度表达,恢复肾皮质中Nephrin、P-cadherin表达有关,即与抑制DN肾皮质中上皮细胞向间充质细胞转分化(epithelial to mesenchymal transition,EMT)有关。

Objective To examine the protective effects of Jixuepaidu Tang-1on renal injury of mice with streptozotocin（STZ）-induced diabetic nephropathy（DN）and the possible mechanism.Methods Eight-week-old C57BL/6j male mice under SPF conditions were divided into 5groups：normal control group,DN group,high-dose Jixuepaidu Tang-1group,low-dose Jixuepaidu Tang-1group,fosinopril sodium group,with 8mice in each group.Different treatments were given to mice 2weeks after DN was induced by intraperitoneal injection of STZ.The body weight,kidney weight,ratio of kidney to body weight,blood glucose,blood serum creatine and 24-h urinary protein were detected after 4-week treatments.The glomerular mesangial extracelluar matrix（ECM）deposition was assessed using Periodic acid-schiff（PAS）staining.The expression levels ofα-SMA,FN,Nephrin and P-cadherin were detected by Western blotting.The ultrastructure of the kidney and the glomerular basement membrane（GBM）thickness were detected by transmission electron microscopy.Results The body weight,and renal cortical expression levels of Nephrin and P-cadherin were significantly reduced and the glomerular mesangial matrix,ratio of kidney to body weight,blood glucose,24-h urinary protein and renal cortical expression levels ofα-SMA and FN were significantly increased in DN,fosinopril sodium,high-dose and low-dose Jixuepaidu Tang-1groups when compared with those in normal control group（P0.05）.These indices were greatly improved in fosinopril sodium group,high-dose and low-dose Jixuepaidu Tang-1groups as compared to DN group（P0.05）.The GBM thickness was reduced significantly in high-dose and low-dose Jixuepaidu Tang-1groups relative to DN group and fosinopril sodium group（P0.05）.Conclusion Jixuepaidu Tang-1can attenuate glomerular mesangial extracelluar matrix deposition,and reduce 24-h urinary protein,ratio of kidney to body weight,GBM thickness and podocytes injury in DN mice.The mechanisms involve the down-regulation of renal cortical expression levels of a-SMA and FN,and up-regulation of renal cortical expression levels of nephrin and P-cadherin in DN mice,i.e.inhibition of renal cortical epithelial to mesenchymal transition（EMT）.