冬虫夏草对糖尿病肾病大鼠肾小管细胞中AMPK/mTOR 信号传导途径的影响

Cordyceps sinensis inhibits autophagy through AMPK / mTOR signaling pathway in rat renal tubular cell model

摘要:

目的 研究冬虫夏草（CS）对糖尿病肾病大鼠肾小管细胞中AMPK/mTOR 信号传导途径的影响。方法 60 只成年雄性Wistar 大鼠用链脲佐菌素腹腔内注射复制糖尿病肾病（DN）大鼠模型，并随机分为对照组、模型组和实验组。模型构建8 周后处死大鼠，常规测定尿蛋白量和血肌酐；HE 染色检测肾脏病理改变；TUNEL 检测肾小管细胞凋亡；采用Western blot 检测磷酸化腺苷酸激活的蛋白激酶（p-AMPK）、磷酸化哺乳动物雷帕霉素靶蛋白（p-mTOR）和自噬相关蛋白Ⅱ（LC- Ⅱ）的蛋白表达。结果 与模型组比较，实验组CS 可降低糖尿病肾病大鼠的物理和生化指标，差异有统计学意义（P <0.05）；HE 染色观察，CS 可以有效缓解肾小管损伤和肾小管上皮细胞脱落死亡。与模型组比较，实验组肾小管上皮细胞凋亡数降低，差异有统计学意义（P <0.05）；实验组p-mTOR 蛋白含量升高，p-AMPK 和LC- Ⅱ的蛋白含量降低，差异有统计学意义（P <0.05）。结论 冬虫夏草具有肾脏保护作用，可能与调节肾小管上皮细胞中自噬相关的AMPK/mTOR 信号通路有关。

Abstract:

Objective To investigate the effect of cordyceps sinensis (CS) on regulating autophagy in rat renal tubular cells model. Methods Streptozotocin was injected intraperitoneally to establish rat model of diabetic nephropathy (DN), and 60 rats were randomly divided into control group, model group and experimental group.Rats were sacrificed 8 weeks post strptozotocin injection. Urine protein and serum creatinine were quantified.HE staining was performed to observe renal pathological abnormality. TUNEL analysis was utilized to determine apoptosis rate of renal tubular cell. Expression levels of p-AMPK, p-mTOR and LC-II were measured by Western blot. Results Physical as well as biochemical abnormalities in model group was significantly attenuated by CS treatment (P < 0.05). HE staining suggested that streptozotocin-induced renal tubular injury and renal tubular epithelial cell shedding death were ameliorated dramatically by CS. Apoptosis rate of renal tubular epithelial cells in experimental group was significantly decreased when compared with that in model group (P < 0.05).Conclusion CS preserves renal function by inhibition of AMPK / mTOR signaling pathway-mediated autophagy in renal tubular epithelial cells.