The changes and role of TGF-β1/Smads signaling protein in the peritoneal fibrogenesis process in rats

Objective To explore the changes and role of TGF-β1/Smads signaling protein in peritoneal fibrogenesis process induced by 4.25% peritoneal dialysate and LPS in rats. Methods 32 male SD rats were randomly allocated into four groups:normal control group,normal rats (n=8); model group (n=24):rats were treated with daily intraperitoneal injection of 4.25% peritoneal dialysate (100ml/kg body weight) and LPS (0.6mg/kg,2 to 3 times per week); model group rats were randomly allocated into 2W model group,4W model group and 6W model group. A survival peritoneal equilibration test (PET) was performed in each animal,a tail blood sample and a peritoneal fluid sample were obtained at 0h and 4h. After 4h later,the animal was killed,the parietal peritoneum was stained with Masson and HE. The expression of α-SMA,TGF-β1,p-Smad2/3,and COL-Ⅰin visceral peritoneum was detected with confocal microscope by immunoflurence,Western-blot and RT-PCR. Results Normal peritoneum was covered by a layer flat mesothelial cell. Comparing with the rats in normal group,the peritoneum thickness and collagen deposition was significantly increased in the submesthelial compact zone and the expression of TGF-β1,p-Smad2/3,α-SMA,and Col-Ⅰwas upregulated in model group. Conclusions The activation of TGF-β/Smads signaling protein by 4.25% peritoneal dialysate and LPS involved in peritoneal fibrogenesis process ,the fibrosis model presents a persistent and slow progress in 6 weeks,thus it give us a basic model to investigate therapy for peritoneal fibrosis.