Klotho蛋白对肾缺血再灌注大鼠急性肾损伤及 纤维化的保护作用.

Objective To investigate the role of Klotho protein in acute renal injury and fibrosis induced by ischemiareperfusion (I/R) in rats. Methods Sixty healthy SD rats were randomly divided into the sham operation group (sham group), the renal ischemia-reperfusion group (I/R group) and the Klotho protein intervention group (I/R+Kl group), with 20 rats in each group. In the I/R group, the acute renal injury model of I/R was established by clamping the right renal pedicle for 40 min. In the sham group, the right renal artery was dissociated, but the right renal pedicle was not clamped. After exposure for 40 minutes, the abdominal cavity was sutured. The operation method of the I/R+Kl group was the same as that of the I/R group. Kiotho protein (0.01 mg/kg) was injected intraperitoneally. The blood and renal tissue samples were collected on the 1st, 7th, 14th and 28th days after successful modeling in the three groups, and blood creatinine (Scr) and blood urea nitrogen (BUN) were measured respectively. HE staining was used to observe the damage of renal tissue. Masson staining was used to observe the renal fibrosis. ELISA was used to detect levels of Klotho protein in blood and renal tissue. Western blot assay was used to detect the expression of Klotho protein in renal tissue. Results Compared with the sham group, levels of SCR and BUN were increased in the I/R group and the I/R+Kl group (P＜0.05). Compared with the I/R+Kl group, serum levels of SCR and BUN were increased in different time points in the I/R group (P＜0.05). HE staining showed extensive acute necrosis of renal tubules in the I/R group, and the injury was mild in the I/R+Kl group. Masson staining showed that mild fibrosis occurred in the I/R group on the 14th day, and the degree of fibrosis was more significant on the 28th day, while the degree of fibrosis was very mild in the I/R+Kl group (P < 0.05). ELISA results showed that compared with the Sham group at day 1, 14 and 28, levels of Klotho in blood and renal tissue decreased significantly in the I/R+Kl group and the I/R group, and the level of Klotho decreased in the I/R group than that of the I/R+Kl group (P＜0.05). Western blot results showed that compared with the Sham group, Klotho levels were decreased at all time points in the I/R group and the I/R+Kl group. while Klotho levels were higher in the I/R+Kl group than those in the I/R group (P＜0.05). Conclusion Klotho expression is down-regulated during renal I/R injury. Exogenous supplementation of Klotho protein can alleviate acute renal injury and fibrosis in rats with renal I/R injury and play a role in renal protection. [ABSTRACT FROM AUTHOR]

目的 探讨Klotho蛋白在缺血再灌注 (I/R) 大鼠引起的急性肾损伤及纤维化进程中的作用. 方法 60只 健康雄性SD大鼠按随机数字表法分为假手术组 (Sham组)、肾脏缺血再灌注组 (I/R组) 和Klotho蛋白干预组 (I/R+Kl 组), 每组20只. I/R组采用夹闭右侧肾蒂40 min再灌注法建立肾缺血再灌注急性肾损伤模型. Sham组游离出右侧 肾动脉, 但不夹闭右侧肾蒂, 暴露40 min后缝合腹腔. I/R+Kl组手术方法同I/R组, 造模成功后, 腹腔注射Klotho蛋白 (0.01 mg/kg). 3组分别于造模成功后第1、7、14、28天收集大鼠血、肾组织标本, 分别检测大鼠血肌酐 (Scr)、尿素氮 (BUN) 水平; HE染色观察肾组织损伤情况, Masson染色观察肾纤维化情况, 酶联免疫吸附试验 (ELISA) 检测血清及 肾组织Klotho蛋白水平, Western blot法检测肾脏组织Klotho蛋白的表达. 结果 与Sham组比较, I/R组及I/R+Kl组 血Scr及BUN水平均升高 (P＜0.05), 与I/R+Kl组比较, I/R组各时间点血Scr及BUN水平均升高 (P＜0.05). HE染色 结果显示, 第1天时I/R组肾小管出现广泛急性坏死, I/R+Kl组损伤较轻微. Masson染色结果显示, I/R组第14天出现 了轻度的纤维化, 第28天时纤维化程度更为显著, I/R+Kl组纤维化程度较轻微 (P＜0.05). ELISA结果显示, 第1、14、 28天时与Sham组比较, I/R+Kl组及I/R组血清及肾组织Klotho水平下降 (P＜0.05), I/R组血清及肾组织Klotho水平均 低于I/R+Kl组 (P＜0.05). Western blot结果显示, 与Sham组比较, 各时间点I/R组及I/R+Kl组Klotho水平均下降, 而 I/R+Kl组Klotho水平均高于I/R组 (P＜0.05) . 结论 肾缺血再灌注肾损伤时Klotho表达下调; 外源性补充Klotho蛋 白可缓解缺血再灌注肾损伤大鼠的急性肾损伤及纤维化, 起到肾保护作用. [ABSTRACT FROM AUTHOR]