Objective:To investigate the effect of specific inhibition of transforming growth factor-β1 (TGF-β1) with SB-431542 on the Smad2/3 and integrin-linked kinase (ILK) signaling molecules in tubule interstitial fibrosis(TIF)-induced cyclosporine A(CsA) in mouse.Methods:50 BALB/c mice were randomly divided into 5 groups (10 mice per group):the CsA model group (CMG),the interventional model group (IMG),the solvent control group (SCG),the low-salt control group (LCG),and the normal control group (NCG).The model mouse was established with low-sodium diet and intragastric administration of cyclosporine A,which was dissolved in olive oil at a dose of 60 mg/(kg·d).After 4 weeks,a specific inhibitor of TGF-β1 (SB-431542)was administered intraperitoneally with 10 mg/(kg·2 d) for 10 days (every other days).Mice were sacrificed at day 38.Serum creatinine (Scr) was measured,hydroxyp roline (Hyp)level and morphological changes of renal tissue were analyzed,expression levels of TGF-β1,P-Smad 2/3 and ILK were respectively detected by immunohistochemistry or Western blot,mRNA levels of TGF-β1,Smad 2/3 and ILK were respectively detected real-time polymerase chain reaction (RT-PCR).Results:Compared with three control groups (NCG,LCG and SCG),mice weight was decreased significantly,Scr level was increased significantly in two modeling groups (CMG and IMG) (P<0.01),and these changes in CMG were more obvious than those of IMG (P<0.05).Different levels of tubulointerstitial injury,interstitial infiltration of inflammatory cells and blue collagen staining in two modeling groups were observed,and particularly evident in CMG.TGF-β1,P-Smad2/3 and ILK immunostaining were mainly expressed in tubulointerstitium.The TGF-β1,P-Smad2/3 and ILK mRNA and immunostaining levels in two modeling groups were significantly increased as compared with three control groups (P<0.01),but their levels in IMG were significantly lower than those of CMG (P<0.05).The level of Hyp in renal tissue was positively correlated with Scr,TGF-β1,Smad2/3 and ILK (r=0.860,0.711,0.776,0.676,P<0.01).Conclusion:The activation of the TGF-β1/Smads signaling pathway plays an important role in the development of chronic CsA-induced TIF.The activation of ILK is closely correlated with the development of TIF,and may be used as a downstream factor of TGF-β1/Smads signaling pathway in regulating CsA-induced TIF.

This study was designed to explore the effect of up-regulation of interleukin(IL)-37a expression on lung function and T helper type 1(Th1)/Th2 cytokine balance in rats with acute respiratory distress syndrome(ARDS).Mesenchymal stem cells(MSCs)overexpressing IL-37a were constructed and co-cultured with mononuclear cells,then flow cytometry was used to detect the effect of IL-37a overexpression on Th1 and Th2 expression,and ELISA was used to detect IFN-γ and IL-4 levels in supernatant of the culture medium.Total of 30 SD rats were recruited and randomly divided into control group(sham surgery),ARDS group(lipopolysaccharideinduced establishment of ARDS model),and IL-37a group(ARDS model+tail vein injection of 10 μg/kg IL-37a),with 10 rats in each group.After 12 hours of modeling,arterial oxygen pressure(PaO2)and oxygenation index(PaO2/FiO2)were measured using a blood gas analyzer,and the dry/wet(W/D)ratio of the lungs was measured.HE staining was used to observe lung tissue pathology and evaluate lung pathological injury scores;ELISA was used to detect alveolar lavage fluid(BALF)and serum IL-4 and IFN-γ expression;flow cytometry was used to detect spleen Th1/Th2;while Western blot was used to detect the protein expression of NF-κB and NLRP3 in lung tissue.Data showed that the levels of Th1,Th1/Th2,and IL-4 in the peripheral cells of the overexpression IL-37a group were lower than those in the negative control group cells,while the expression of Th2 and IFN-γ were higher than those in the negative control group cells(P＜0.05).Compared with the control group,the ARDS group showed lower levels of PaO2,PaO2/FiO2,BALF and serum IL-4,but higher levels of W/D,lung pathological injury score,BALF and serum IFN-γ,spleen Th1/Th2,and lung tissue NF-κB and NLRP3 proteins.IL-37a could reverse the changes mentioned above in ARDS rats(P＜0.05).Taken together,up-regulation of IL-37a expression can ameliorate lung injury in ARDS rats,which may be related to the role of IL-37a in inducing MSC differentiation and promoting the restoration of Th1/Th2 balance.