ABSTRACT
Objective To study the protective effect of the sodium selenite and benazepril on renal interstitial fibro-sis(RIF) in rat model of unilateral ureteral obstruction(UUO) and its mechanism. Methods The male SD of clean grade rats were randomly divided into sham-operation group,UUO group(UUO model was established by li-gating unilateral ureter), UUO+ sodium selenite group group(sodium selenite 0.2 mg/kg·d gavage), UUO+benazepril group(benazepril 10 mg/kg·d gavage),with 18 in each group.At day 7,14 and 21 after thetreatment, 6 rats selected randomly from each group were killed.The extent of RIF was evaluated by HE and Masson staining of the renal tissue. The expression of connective tissue growth factor(CTGF),transforming growth factor-β1(TGF-β1), alpha smooth muscle actin(α-SMA) andⅢ collagen(ColⅢ) were detected by immunohistochemical method.The protein expression of CTGF and TGF-β1 were detected by Western blot. Chemical colorimetric method was used to detecte the contents of supper oxide dismutase (SOD),malondialdehyde (MDA) and glutathione peroxidase (GSH-px) in renal cortex. Results The extent of RIF and the expression of CTGF,TGF-β1,α-SMA and ColⅢin renal cortex were significantly lower in sodium selenite group and benazepril group at day 7,14 and 21 after the op-eration compared with that in UUO group(P<0.05 or P<0.01). In sodium selenite group and benazepril group,the contents of SOD and GSH-px in renal cortex were higher significantly than those in UUO group at day 7,14 and 21 after the operation respectively(P<0.05),but the MDA in renal cortex was significantly decreased(P<0.05).There were no significant differences in the indexes between the two groups of sodium selenite and benazepril. The expres-sion of CTGF,TGF-β1,α-SMA,ColⅢand the extent of RIF were positively correlated to the level of MDA in UUO group(P<0.05,respectively),and negatively correlated to the level of SOD and GSH-Px(P<0.05,respectively). The expression of CTGF was positively correlated to the expression of α-SMA and ColⅢin UUO group(P<0.05).The expres-sion of CTGF,α-SMA and ColⅢwere positively correlated to RIF in UUO group(P<0.05).Conclusions Sodium sele-nite and benazepril can reduce the extent of RIF in rat model with unilateral ureteral obstruction.
ABSTRACT
To investigate the effect and mechanism of miR-498 on Th17 cell differentiation of peripheral blood mononuclear cells (PMBCs) in rheumatoid arthritis (RA) patients, peripheral blood samples were collected from RA patients and healthy controls, respectively. The proportion of CD4IL-17 T cells (Th17 cells) or CD4FOXP3 T cells (Tregs) in T cells and the Th17/Treg ratio were identified by the flow cytometer. The STAT3 and miR-498 expression were measured by Western blot and real-time PCR, respectively. ELISA was used to detect IL-17 concentrations. Luciferase assay was performed to confirm that miR-498 directly targeted the 3' untranslated region (3'UTR) of STAT3 in CD4 T cells. The effect of miR-498 on Th17 cell differentiation was explored by transfection of miR-498 mimic and/or pcDNA-STAT3 into CD4 T cells. In PMBCs of RA patients, the Th17/CD4 T cell ratio was significantly increased, while the Tregs/CD4 T cell ratio was obviously decreased, leading to a higher Th17/Treg ratio. The results showed a reduced miR-498 expression and an increased STAT3 protein expression in PMBCs, and an increased IL-17 concentration in serum of RA patients. In cells transfected with wild-type-STAT3-LU, miR-498 mimic significantly reduced the luciferase activity, STAT3 gene and protein expression, and miR-498 inhibitor had an opposite function. While the miR-498 mimic/inhibitor had no effect on the luciferase activity and STAT3 expression in cells transfected with mutant-STAT3-LU. CD4 T cells transfected with miR-498 mimic had a lower Th17/CD4 T cell ratio and IL-17 concentration, however, transfection of pcDNA-STAT3 reversed the effect of miR-498 mimic on Th17/CD4 T cell ratio and IL-17 concentration. These results suggest that overexpression of miR-498 suppresses Th17 cell differentiation by targeting STAT3 in RA patients.