Study On The Role Of Albumin Overload In Renal Proximal Tubular Epithelial Cells In Damaging Peritubular Capillary Network

BackgroundIt has been proved that severity of tubulointerstitial injuries is closely correlated with chronic renal disease aggravating to renal failure. The causes for tubulointerstitial changes remain rather complex and the role of proteinuria in damaging nephridial tissue has been demonstrated by large number of clinical and experimental studies. Overload of albumin can stimulate renal tubular epithelial cells (RTEC) and in turn result in a series of pathophysiological changes including tubulointerstitial inflammation, accumulation of extracellular matrix (ECM) and transdifferentiation of RTEC, which finally leads to interstitial fibrosis. Recent studies have indicated an intimate relation between changes of peritubular capillary (PTC) and interstitial fibrosis. However, the causes and possible mechanisms of PTC injury still remain unclear at present.RTEC is connected with interstitial fibroblasts and endothelial cell of PTC. Overload of albumin can damage RTEC and further activate fibroblasts and facilitate interstitial fibrosis. It is found that normal RTEC plays important role in maintenance of normal structure and physiological function of PTC, for it can express vascular growth factor (VGF) like vascular endothelial growth factor (VEGF). VEGF can accelerate proliferation and repair of epithelial cells under state of renal disease. Nevertheless, it is still uncertain whether overload of albumin inducing injury or activation of RTEC will involve adjacent endothelial cells, results in ischemia and hypoxia of interstitials and facilitates interstitial fibrosis. Provided that the above mentioned mechanisms of proteinuria in damaging nephridial tissues exits, if inhibiting reabsorption of albumin and the intervention via reabsorption of RTEC in patients with proteinuric renal diseases can ameliorate peritubular capillary injury and slow down development of chronic renal disease to renal failure?The objective of the study is to observe the change of PTC and its relation with...