硒对肾间质纤维化大鼠肾组织结缔组织生长因子表达及肾小管上皮细胞表型转化的影响

摘要

目的探讨硒对肾间质纤维化大鼠肾组织结缔组织生长因子（CTGF）表达及肾小管上皮细胞表型转化的影响。方法以单侧输尿管结扎致肾间质纤维化大鼠模型。将54只SD大鼠随机分为假手术组（A组）、单侧输尿管梗阻（UUO）组（B组）、U-UO+硒组（C组），每组18只。C组给予亚硒酸钠0.2mg/（kg·d）灌胃。A、B组给予同等剂量0.9%氯化钠溶液灌胃。术后第7、14、21天各组随机处死6只大鼠，肾组织行HE、Masson染色评定肾间质纤维化程度，免疫组织化学半定量法检测CTGF和α-平滑肌肌动蛋白（α- SMA）的表达。Western印迹法检测肾组织CTGF蛋白表达。化学比色法检测肾组织氧化指标谷胱甘肽过氧化物酶（GSH- Px）、超氧化物歧化酶（SOD）、丙二醛（MDA）的表达水平。结果术后各时点C组肾间质纤维化程度较B组明显减轻（P＜0.05），肾组织CTGF和α- SMA的表达强度明显低于B组（P＜0.05或0.01）、GSH- Px和SOD水平明显高于B组（P＜0.05），MDA含量明显低于B组（P＜0.05）。B组肾组织中CTGF、a- SMA表达量之间呈正相关（P＜0.05），CTGF和a- SMA表达量与肾间质纤维化病变程度呈正相关（P＜0.05）。结论硒可以减轻UUO模型大鼠肾间质纤维化程度，其机制可能与硒的抗氧化作用、下调肾组织CTGF的表达、抑制肾小管上皮细胞－肌成纤维细胞转分化有关。%Objective To investigate the effect of selenium on expression of connective tissue growth factor(CTGF)and transdifferentiation of renal tubular epithelial cel s in rat model of unilateral ureteral obstruction (UUO). Methods Fifty four male SD rats were randomly divided into 3 groups:sham- operation group (group A), UUO group (group B), UUO+sodium selenite group (group C) with 18 animals in each group. The unilateral ureteral obstruction was induced by ligation of unilateral ureter in groups B and C. Rats in group C received sodium selenite 0.2mg/ (kg-1·d-1) by gastric lavage 1d before operation;same volume of normal saline was administrated in groups A and B. At d7, 14 and 21 after the treatment, 6 rats from each group were randomly sacrificed. The extent of renal interstitial fibrosis was evaluated by HE and Masson staining of the renal tissue sections. Immuno-histochemical method and Western blot were used to examine the expression of CTGF and α- smooth muscle actin (α- SMA). Superoxide dismutase(SOD), malondialdehyde(MDA) and glutathione peroxidase(GSH- px) levels in renal cortex were measured by colorimetric assay. Results The extent of renal interstitial fibrosis and the expression of CTGF and α- SMA in renal cortex were significantly lower in group C at d7,14 and 21 after the operation, compared to those in group B (P<0.05 or P<0.01). The contents of SOD and GSH- px in renal cortex of group C were significantly higher than those in group B at d7, 14 and 21, respec-tively(P<0.05), while the MDA level in renal cortex was significantly decreased(P<0.05). The expression of CTGF andα- SMA in renal cortex was positively correlated to the extent of renal interstitial fibrosis in group B(r=0.817, P<0.05;r=0.829, P<0.05, re-spectively);and CTGF andα- SMA was positively correlated with each other(r=0.803, P<0.05). Conclusion Selenium may re-Objective To investigate the effect of selenium on expression of connective tissue growth factor(CTGF)and transdifferentiation of renal tubular epithelial cel s in rat model of unilateral ureteral obstruction (UUO). Methods Fifty four male SD rats were randomly divided into 3 groups:sham- operation group (group A), UUO group (group B), UUO+sodium selenite group (group C) with 18 animals in each group. The unilateral ureteral obstruction was induced by ligation of unilateral ureter in groups B and C. Rats in group C received sodium selenite 0.2mg/ (kg-1·d-1) by gastric lavage 1d before operation;same volume of normal saline was administrated in groups A and B. At d7, 14 and 21 after the treatment, 6 rats from each group were randomly sacrificed. The extent of renal interstitial fibrosis was evaluated by HE and Masson staining of the renal tissue sections. Immuno-histochemical method and Western blot were used to examine the expression of CTGF and α- smooth muscle actin (α- SMA). Superoxide dismutase(SOD), malondialdehyde(MDA) and glutathione peroxidase(GSH- px) levels in renal cortex were measured by colorimetric assay. Results The extent of renal interstitial fibrosis and the expression of CTGF and α- SMA in renal cortex were significantly lower in group C at d7,14 and 21 after the operation, compared to those in group B (P<0.05 or P<0.01). The contents of SOD and GSH- px in renal cortex of group C were significantly higher than those in group B at d7, 14 and 21, respec-tively(P<0.05), while the MDA level in renal cortex was significantly decreased(P<0.05). The expression of CTGF andα- SMA in renal cortex was positively correlated to the extent of renal interstitial fibrosis in group B(r=0.817, P<0.05;r=0.829, P<0.05, re-spectively);and CTGF andα- SMA was positively correlated with each other(r=0.803, P<0.05). Conclusion Selenium may re-duce the extent of renal fibrosis in rat UUO model, which may be related to anti- oxidant and down- regulation of CTGF andα- SMA expression in renal tissue and inhibition of transdifferentiation of renal tubular epithelial cel s.