Changes Of Expression Of Periostin In Myocardium Of Diabetic Rats And The Effect Of Valsartan On It

Objective:Periostin, an important extracellular matrix protein, which plays an significant role in cardiac hypertrophy and myocardial interstitial fibrosis caused by myocardial infarction, heart failure or other reasons. However, no report has documented the function and change of periostin in left ventricular remodeling of streptozototin(STZ)-induced DCM rats. To observe the expression of periostin in wistar rats myocardium of diabetic cardiomyopathy(DCM) and the effect of Valsartan on it.Methods:DCM rats model was induced by a single intraperitoneal injection of streptozotocin(STZ), then the eligible diabetes rats were randomly assigned to two groups based on whether treated by valsartan or not and the control group was normal wistar rat, all animals were killed,collected and weighted hearts 16 weeks after STZ injections and treated with valsartan. HE staining was used to study the pathological changes and Masson staining was used to quantify the collagen content in the myocardium of three groups. The mRNA and protein expressions of periostin, transforming growth factor-β1(TGF-β1),transforming growth factor-β1 type Ⅱ receptor(TGF-β1 RⅡ), type Ⅰand Ⅲ collagen of three groups were detected by real-time RT-PCR, Western blot and Immunohistochemistry.Results: Compared with the non-diabetic controls,the myocytes and nuclear from the DCM group arranged irregularly as well as the cardiac collagen deposition was obviously enhanced. Moreover, significant upregulation of periostin mRNA and protein were detected in diabetic group. In addition, TGF-β1, TGF-β1 RⅡ, type Ⅰand Ⅲ collagen were used to evaluate the myocardial fibrosis were also significantly enhanced in the myocardium of DCM rats compared with control rats on mRNA and protein levels, the difference was statistically significant. while being treated with valsartan, the abnormal changes of DCM rats were significantly ameliorate, the difference was also statistically significant.Conclusion: Periostin may play a crucial role in cardiac remodeling and myocardial interstitial fibrosis process of DCM, and it could be one of the important mechanisms for valsartan to improve the ventricular remodeling of DCM.