Thrombospondin-1 expression in the kidney of a rat model of fibrosis / 中国组织工程研究

ABSTRACT

BACKGROUND:Thrombospondin-1 is an important endogenous activator of transforming growth factor beta 1 in this experimental inflammatory kidney disease model. Transforming growth factor beta 1 is considered the major cytokine that causes tissue fibrosis in many different inflammatory disease processes, in particular in renal disease. OBJECTIVE:To investigate the expression of thrombospondin-1 on renal fibrosis in rats. METHODS:Healthy male Sprague-Dawley rats were randomly divided into sham surgery group and model group. In themodel group, right ureters of rats were ligated to construct models of renal fibrosis. 3 weeks after surgery, blood and urine were obtained weekly. Enzyme linked immunosorbent assay and Bradford method were used to detect the contents of serum creatinine,blood urea nitrogen and urinary protein. After rats were sacrificed, kidneys were fixed. Western blot assay was utilized to identify the expression of vascular endothelial growth factor, transforming growth factor beta 1 and thrombospondin-1 protein. Hematoxylin-eosin staining was applied to detect the changes in pathological structure of the kidney after surgery. RESULTS AND CONCLUSION:(1) One week after model induction, urinary protein, serum creatinine and urea nitrogen levels were significantly higher in the model group than in the sham surgery group (P< 0.05). Three weeks later, the difference in each index was significant (P< 0.01), which showed that the injury of the kidney was aggravated. (2) Transforming growth factor beta 1 protein and thrombospondin-1 expression was significantly higher in the model group than in the sham surgery group, but vascular endothelial growth factor protein expression was significantly lower in the model group than in the sham surgery group. (3) Hematoxylin-eosin staining results demonstrated that severe pathological changes of renal tissue in rats were detected after ligation of renal tubule. (4) These results confirmed that thrombospondin-1 expression increased in renal tissue, and its expression was strongly associated with vascular endothelial growth factor protein and transforming growth factor beta 1, which may play an important role in the renal fibrosis.