新型磷酸二酯酶5抑制剂CPD1对单侧输尿管梗阻引起的肾间质纤维化小鼠治疗作用

Effect of a novel phosphodiesterase type 5 inhibitor,CPD1,on unilateral renal interstitial fibrosis caused by ureteric obstruction in mice

目的探讨新型磷酸二酯酶5抑制剂CPD1对单侧输尿管梗阻(unilateral ureteric obstruction,UUO)诱导的肾纤维化小鼠肾脏组织结构损伤及间质纤维化的影响。方法8周龄♂C57BL/6 J小鼠随机分为假手术组、模型组、CPD1治疗组,手术结扎模型组和治疗组小鼠左侧输尿管,假手术组仅分离输尿管而不结扎。造模2 h后,给予CPD1(5 mg·kg^(-1)·d^(-1))灌胃治疗,持续7 d。通过组织病理学染色和Western blot,观察CPD1治疗对UUO小鼠患侧肾脏组织结构病变和纤维化标志蛋白:纤维连接蛋白(fibronectin,FN)、α平滑肌肌动蛋白(α-SMA)、Ⅰ型胶原(collagen-Ⅰ)、肾损伤分子-1(kidney injury molecule 1,Kim-1)表达及分布的影响。结果与假手术组相比,UUO组小鼠患侧肾组织中肾小管扩张,可见明显空泡变性,炎症浸润增加,FN、α-SMA、collagen-I及Kim-1蛋白的表达明显增加(P<0.05);CPD1可明显改善UUO模型小鼠患侧肾脏的结构,降低胶原纤维蛋白的沉积,纤维化标志蛋白FN、α-SMA、collagen-I及Kim-1的表达均得到明显抑制(P<0.05)。结论磷酸二酯酶5抑制剂CPD1通过下调细胞外基质ECM的沉积,减少Kim-1介导的肾损伤,改善输尿管梗阻诱导的肾间质纤维化,其具体的作用机制还有待进一步研究。

Aim To investigate the effects of CPD1,a novel phosphodiesterase 5 inhibitor,on renal pathological phenotype and fibrotic protein expression in renal fibrosis model mice.Methods Male C57BL/6 J mice were divided into three groups randomly(sham group,UUO group and UUO+CPD1 group).Unilateral ureteric obstruction model was constructed by surgery,and CPD1(5 mg·kg^(-1)·d^(-1))was administered by intragastric administration two hours after the modeling for seven days.HE and Sirius Red staining were used to observe the distribution of tissue structural lesions and fibrosis.Immunohistochemical staining and Western blot were used to detect the expression of fibronectin(FN),α-SMA,collagen-I and kidney injury molecule-1(Kim-1).Results Compared with sham operation group,the renal tubules of mice were dilated and accompanied by a large amount of inflammatory infiltration.Moreover,the expressions of FN,α-SMA,collagen-Ⅰ and Kim-1 proteins increased significantly(P<0.05)in UUO group.CPD1 treatment improved the kidney structure and decreased the expression of collagen fibers.Furthermore,CPD1 inhibited the expression of FN,α-SMA,collagen-Ⅰ and Kim-1 markedly(P<0.05).Conclusions Phosphodiesterase 5 inhibitor CPD1 alleviates the progression of renal fibrosis induced by unilateral ureteral obstruction through down-regulating ECM deposition in the extracellular matrix and expression of Kim-1.The specific mechanism remains to be further studied.