胰激肽原酶减轻单侧输尿管梗阻大鼠肾间质纤维化

Pancreatic kininogenase protects against renal fibrosis in rat model of unilateral ureteral obstruction

目的:探讨胰激肽原酶(PK)对单侧输尿管梗阻(UUO)所致肾间质纤维化大鼠肾脏的保护作用。方法:雄性Sprague-Dawley大鼠建立UUO模型后随机分为4组:UUO7组、UUO14组、UUO+PK7组和UUO+PK14组,其中UUO+PK7组和UUO+PK14组给予腹腔注射PK(7.2 U·kg^−1·d^−1)治疗14 d,分别于第7天和第14天处死大鼠;假手术组给予生理盐水。采用Masson染色、HE染色和透射电镜观察各组大鼠的肾间质纤维化程度;免疫组化和Western blot法分别检测炎症因子、致纤因子、氧化应激、细胞凋亡及细胞自噬调控因子的表达。结果:PK治疗明显减轻UUO大鼠肾小管间质纤维化程度,并呈时间依赖性,这种改善伴随着炎症介质[单核细胞趋化蛋白1(MCP-1)和Toll样受体2(TLR-2)]及致纤因子[转化生长因子β1(TGF-β1)和结缔组织生长因子(CTGF)]的表达下调。UUO所致氧化应激表现为氧化酶[NADPH氧化酶2(NOX-2)和NOX-4]的表达增加和抗氧化酶[超氧化物岐化酶1(SOD1)和SOD2]的表达下降,这种改变与细胞凋亡(Bcl-2/Bax和cleaved caspase-3)及细胞自噬(LC3B、beclin-1和P62)调控因子表达失衡紧密相关,PK逆转了上述所有指标。结论:PK可能通过干预氧化应激和程序性细胞死亡对单侧输尿管梗阻大鼠肾脏具有抗纤维化作用。

AIM:To assess the beneficial effects of pancreatic kininogenase(PK)on renal fibrosis in rat model of unilateral ureteral obstruction(UUO).METHODS:Male Sprague-Dawley rats were randomly assigned to 5 groups and treated daily with PK for 7 d and 14 d.Masson trichrome and HE staining were used to assess the degree of tubulointerstitial fibrosis,and immunohistochemistry and Western blot were employed to evaluate the expression of profibrotic and proinflammatory cytokines,and apoptosis-and autophagy-related proteins.RESULTS:PK treatment significantly decreased expression of profibrotic and proinflammatory cytokines,and these were paralleled with attenuation of tubulointerstitial inflammation[monocyte chemoattractant protein-1(MCP-1)and Toll-like receptor 2(TLR-2)]and fibrosis[transforming growth factorβ1(TGF-β1)and connective tissue growth factor(CTGF)]in a time-dependent manner.Oxidative stress induced by UUO manifested by augment of oxidant enzymes[NADPH oxidase-2(NOX-2)and NOX-4]and decrease in antioxidant enzymes[superoxide dismutase 1(SOD1)and SOD2],which was closely associated with dysregulation of apoptosis-and autophagy-related proteins subsequent excessive apoptotic(Bcl-2/Bax and cleaved caspase-3)and autophagy(LC3B,beclin-1 and P62),and all of these were eliminated by administration of PK.CONCLUSION:PK treatment protects against the progression of renal fibrosis in obstructed kidneys probably by interfering oxidative stress and programmed cell death.