BMP-7/Smad 2在糖尿病大鼠心肌纤维化中的表达变化

The expression of BMP-7 and Smad 2 in myocardium of diabetic cardiomyopathy induced by streptozotocin

目的研究骨形态发生蛋白-7(BMP-7)/Smad 2在糖尿病心肌纤维化中的表达变化,初步探讨糖尿病心肌病的病理生理机制。方法将30只Wistar大鼠随机分成2组,即对照组15只、糖尿病组15只。腹腔注射60 mg/kg链脲佐菌素制备糖尿病组,成模后用HE染色、Masson三色染色、免疫组织化学方法,分别观察心肌组织、心肌胶原的变化,BMP-7和Smad 2的表达变化。结果 HE染色发现糖尿病组心肌细胞肥大、扭曲,心肌间质不清;Masson三色染色可见糖尿病组心肌胶原纤维明显增多;免疫组化结果显示糖尿病组中心肌BMP-7的表达较正常组减少(P<0.05),Smad 2的表达较正常组增多(P<0.05)。结论糖尿病心肌纤维化中BMP-7表达减少,Smad 2表达增多,二者在糖尿病心肌纤维化中起着相反的作用。

Objective To investigate the role of bone morphogenetic protein- 7( BMP- 7) and drosophila mothers against decapentaplegic protein 2( Smad 2) in diabetic cardiomyopathy. Methods: 30 wistar rats weighting 200 ~ 250 kg were randomly divided into two groups( 15 in each). One group was diabetic cardiomyopathy model group established by a single injection of streptozotocin( STZ) at a dose of 60 mg/kg body weight,while the other group was normal control group injected with citrate buffer solution instead of streptozocin. All of them were tested for six weeks. The expression of collagen was assayed respectively by masson dying techniques and the expressions of BMP- 7 and Smad 2 was assayed by immunohistochemical techniques. Result The Myocardiocytes of rats in diabetes group were hypertrophic and twisted,the myocardial interstitium are not clear. Masson trichrome stain showed that the myocardial collagen fibers in diabetes group are increased obviously. In myocardiocyte of diabetic rats. The expression of BMP- 7 was significant reduced than normal rats in 6 weeks.( P < 0. 05). However,the expression of the Smad 2 and collagen were increased in diabetic rats.Conclusion BMP- 7 is weakly expressed in myocardial fibrosis in diabetic rats and Smad 2 is strongly expressed in myocardial fibrosis in diabetic rats. They plays an opposite role in diabetic cardiomyopathy.