Résumé
Aim To investigate the role of TGF-β/Smad signaling pathway in rheumatoid arthritis (RA) - associated postinterstitial pulmonary fibrosis in mice. Methods The mouse model of RA was constructed by subcutaneous administration of complete Freund's adjuvant (CFA) and chicken II collagen (Col-II) to the tail root of mice. The blank group was given the same amount of distilled water, and the control group was given the same amount of glacial acetic acid (solvent). The degree of toe swelling (joint swelling degree and arthritis index) was monitored to evaluate the mouse modeling. The pathological changes of mouse lung tissues were observed by HE and Masson staining. The expression of TGF-β in lung tissues were observed by immunohistochemical staining. The level of hydroxyproline in lung tissues was measured by chemiluminescence method. The expressions of Smad2, Smad3 and phosphorylated p-Smad2 and phosphorylated p-Smad3 in lung tissues were detected by Western blot. Results Compared with blank group and solvent group, the joint swelling and arthritis index of model group significantly increased. Twenty-one days after administration, HE staining showed inflammatory changes in lung interstitium of the model group, Masson staining showed collagen fiber deposition and obvious fibrosis in lung interstitium of the model group, and immunohistochemical staining showed that the expression of TGF-β in cytoplasm of lung interstitial cells of the model group increased, which was brown and yellow. Meanwhile, hydroxyproline was significantly raised in lung tissue homogenate of the model group. Further WB analysis showed that compared with blank group and solvent group, the expression of p-Smad2 and pSmad3 in lung tissues of the model group was significantly up-regulated (P < 0. 05, P < 0. 01). Conclusions RA can give rise to pulmonary fibrosis, and the expressions of p-Smad2 and p-Smad3 are up-regulated, which is be pivotal in pulmonary fibrosis and RA-related post-interstitial pulmonary fibrosis.
Résumé
Objective To investigate the expression and possible mechanism of miR-21 and Ski-related novel protein N( SnoN) in the renal fibrosis diabetic process.Methods The animal model was established by tail-vein injection of Streptozotocin,and the other group were normal control ( NC) group.After 10 weeks, the rats were sacrificed to measure biochemical parameters and renal index , and to observe the changes of pathomorphology by HE staining as well.Meanwhile, immunohistochemistry and Western blot were employed to examine protein ex-pression of E-cadherin,α-smooth muscle actin(α-SMA), fibronectin(FN), collagen-Ⅰ(Col-Ⅰ), collagen-Ⅲ(Col-Ⅲ), transforming growth factor-β1(TGF-β1), Smad3, p-Smad3(Ser423/425) and SnoN in the renal tissue. In addition, the expression of SonN mRNA and miR-21 were detected by qPCR.Results In DM group,the ex-pressions of Col-Ⅰ, Col-Ⅲ and FN in renal interstitium were increased ( P <0.05 ) , TGF-β1 increased (P<0.05),while E-cadherin decreased(P<0.05).Compared with NC group, the expression of α-SMA,p-Smad3 (Ser423/425) protein increased in DM group(P<0.05),while the protein level of SnoN decreased but the level of SnoN mRNA increased ( P <0.05 ) .Moreover, the level of miR-21 markedly increased in DM group ( P <0.05 ) .Conclusions TGF-β1 may up-regulate the expression of miR-21 but restrain the translational expression of SnoN, aggravating fibrosis.