PDE5抑制剂介导ASK1/JNK蛋白低表达对输尿管梗阻大鼠肾组织损伤保护机制研究

目的 探究PDE5抑制剂介导ASK1/JNK蛋白低表达在输尿管梗阻大鼠肾组织损伤中的保护机制。方法 选取40只SPF级SD雄性大鼠，随机分为正常组（N组），模型组（M组），刺芒柄花素组（F组），PDE5抑制剂组（P组），每组10只，对M、F、P组采用输尿管结扎法进行输尿管梗阻建模，N组不建立该模型，建模成功后，对F组灌胃50 mg/kg的刺芒柄花素，对P组灌胃12 mg/kg的PDE5抑制剂，N组、M组同期给与灌胃同体积生理盐水。全自动生化检测仪检测大鼠肾功能，HE染色法及Masson染色法检测肾组织损伤情况，免疫组化法检测肾组织PDE5阳性表达，免疫印迹法检测大鼠肾组织ASK1/JNK蛋白表达。结果 与N组比较，M组肾脏指数、Scr及BUN含量、肾组织中PDE5阳性表达及ASK1、JNK蛋白表达明显增多（P<0.05）。与M组比较，F、P两组肾脏指数、Scr及BUN含量、肾组织中PDE5阳性表达及ASK1、JNK蛋白表达减少（P<0.05），且P组比F组降低显著（P<0.05）。N组肾组织未见明显病理变化，肾间质无明显纤维组织增生，而M组肾小管可见肾小管上皮细胞出现萎缩、脱落和坏死，可见大量纤维组织增生。与M组比较，F组、P组肾小球、肾小管情况明显改善，肾间质纤维化增生程度明显减轻。与B组比较，A组肾小管上皮细胞中ASK1、JNK蛋白表达降低（P<0.05）。结论 PDE5抑制剂可有效改善输尿管梗阻大鼠肾组织损伤，提高肾功能，抑制PDE5水平，其机制可能与降低ASK1/JNK蛋白表达有关。

Protective mechanism of low ASK1/JNK protein expression mediated by PDE5 inhibitor in renal injury in rats with ureteral obstruction

Objective To explore the protective mechanism of low ASK1/JNK protein expression mediated by PDE5 inhibitor in renal tissue injury in rats with ureteral obstruction. Methods Forty SPF SD male rats were randomly divided into normal group (group N), model group (group M), formononetin group (group F), and PDE5 inhibitor group (group P), with 10 rats in each group. Ureteral obstruction modeling was performed by ureteral ligation in M, F, and P groups, while the model was not established in the N group. The group F was given 50 mg/kg formononeforin by gavage. The group P was given 12 mg/kg PDE5 inhibitor by gavage. Group N and group M were given the same volume of normal saline by gavage at the same time. Automatic biochemical detector was used to detect renal function. HE staining and Masson staining were used to detect renal tissue damage. The positive expression of PDE5 in renal tissue was detected by immunohistochemistry, and the protein expression of ASK1/JNK in renal tissue was detected by Western blot. Results Compared with group N, renal index, Scr and BUN content, positive expression of PDE5 and protein expression of ASK1 and JNK in renal tissue were significantly increased in the group M (P<0.05). The renal index, Scr and BUN content, positive expression of PDE5, and protein expression of ASK1 and JNK in renal tissue were decreased in the group F and P (P<0.05), and the group P decreased more that in the group F (P<0.05). Pathological change was not observed in the group N while renal tubular epithelial cells shrink, fall off and necrosis, numerous fibrous tissue hyperplasia were observed in the group M. Compared with the group M, glomerular, renal tubules, renal interstitial fibrosis hyperplasia were significantly reduced in the group F and P. Compared with the group B, the protein expressions of ASK1 and JNK in renal tubular epithelial cells in group A were decreased (P<0.05). Conclusion PDE5 inhibitor can effectively improve renal tissue injury, improve renal function and inhibit PDE5 level in rats with ureteral obstruction. Its mechanism may be related to reducing the expression of ASK1 / JNK protein.