Investigation Of The Effect And Mechanism Of Rapamycin Treatment With Peritoneal Fibrosis Rats After Long-term Peritoneal Dialysis

Aims:To define the effect and illuminate the lantent signal transduction mechanism of rapamycin treatment with peritoneal fibrosis rats.Methods:(1)In vivo, we classified45normal Sprague Dawley (SD) rats equally into5groups:the nomal ones, the normal saline (NS) ones, the high glucose ones, the low-level rapamycin ones, the high-level rapamycin ones. After6weeks’treatment,we executed all the rats to evaluate the peritoneal function,followed by taking the entire anterior abdominal wall which would be used for HE staining and immunohistochemistry staining of a-SMA and TGF-β.(2) In vitro. Rat peritoneal mesothelium cells (RPMCs) were isolated from normal rats’peritoneal. Some of the subconfluent RPMCs were stimulated with high glucose of different concentration(30,60,120mM) to induce epithelial-mesenchymal transition (EMT) separately for48hours, while others were co-administered with rapamycin(10,100nM). As makers of EMT we included a-SMA and E-cadherin by western blot. Meanwhile, the cell motility were analyzed by the in vitro scratch assay.Results:(1)In vivo.Compared with the normal and NS ones, the peritoneal function of high glucose rats were significantly diminished, which were improved after thetreatment with rapamycin(P<0.05). The HE staining and immunohistochemistry staining of α-SMA and TGF-β also showed the fibrosis statement induced by high glucose.Also the rapamycin ameliorate the fibrosis statement in dosage-dependent manner.(2)In vitro.We found that high concentration of glucose(30,60,120mM) induced EMT of RPMC, suggested by increased expression of α-SMA and decreased expression of E-cadherin and by increased cell migration in dosage-dependent manner(P<0.05). Treatment with rapamycin resulted in a dosage-dependent prevention of high glucose-induced EMT(P<0.05).Conclusions:Rapamycin showed an obvious protective effect on high glucose induced peritoneal fibrosis.It is belived that EMT played a role in the peritoneal fibrosis. We may also concluded that rapamycin prevented EMT and fibrosis through suppression of RPMC migration,reducing the secretion of TGF-β and inhibiting the formation of fibroblasts and extra cellular matrx (ECM)...