Mao Nan, Cheng Yuan, Shi Xin-li, Wang Li, Wen Ji, Zhang Qiong, Hu Qiong-dan, Fan Jun-ming
Department of Nephrology, West China Hospital of Sichuan University, Chengdu 610041, China.
Department of Nephrology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China.
Acta Pharmacol Sin. 2014 Apr;35(4):513-22. doi: 10.1038/aps.2013.187. Epub 2014 Mar 17.
Aldosterone is elevated in many diseases such as hypertension, diabetic nephropathy and chronic kidney disease, etc. The aim of this study was to investigate the effects of aldosterone on intracellular ROS production and autophagy in podocytes in vitro, and to explore the possibility of ginsenoside Rg1 (Rg1) being used for protecting podocytes from aldosterone-induced injury.
MPC5 mouse podocyte cells were tested. Autophagosome and autophagic vacuole formation were examined under confocal microscopy with MDC and acridine orange staining, respectively. ROS were detected with flow cytometry. Malondialdehyde content and superoxide dismutase (T-SOD) activity were measured using commercial kits. The expression of LC3-II, beclin-1, SOD2 and catalase was measured by Western blotting.
Treatment with aldosterone (10 nmol/L) significantly increased ROS generation and the expression of SOD2 and catalase in MPC5 cells. Furthermore, treatment with aldosterone significantly increased the conversion of LC3-I to LC3-II, beclin-1 expression and autophagosome formation. Co-treatment with rapamycin (1 ng/mL) or chloroquine (10 μmol/L) further increased aldosterone-induced autophagosome formation. Co-treatment with Rg1 (80 ng/mL) effectively relieved oxidative stress and increased T-SOD activity at the early stage and subsequently decreased autophagy in aldosterone-treated podocytes. Co-treatment with 3-MA (4 mmol/L) or NAC (50 mmol/L) exerted similar effects against aldosterone-induced autophagy in podocytes.
Aldosterone enhances ROS generation and promotes autophagy in podocytes in vitro. Ginsenoside-Rg1 effectively relieves aldosterone-induced oxidative stress, thereby indirectly inhibiting aldosterone-induced podocyte autophagy.
醛固酮在许多疾病如高血压、糖尿病肾病和慢性肾脏病等中升高。本研究旨在探讨醛固酮对体外足细胞内活性氧(ROS)生成和自噬的影响,并探索人参皂苷Rg1(Rg1)用于保护足细胞免受醛固酮诱导损伤的可能性。
对MPC5小鼠足细胞进行检测。分别用单丹磺酰尸胺(MDC)和吖啶橙染色,在共聚焦显微镜下检查自噬体和自噬泡的形成。用流式细胞术检测ROS。使用商用试剂盒测量丙二醛含量和超氧化物歧化酶(总超氧化物歧化酶,T-SOD)活性。通过蛋白质免疫印迹法检测微管相关蛋白1轻链3-II(LC3-II)、贝林1(beclin-1)、超氧化物歧化酶2(SOD2)和过氧化氢酶的表达。
用醛固酮(10 nmol/L)处理显著增加了MPC5细胞中ROS的生成以及SOD2和过氧化氢酶的表达。此外,用醛固酮处理显著增加了LC3-I向LC3-II的转化、beclin-1表达和自噬体形成。雷帕霉素(1 ng/mL)或氯喹(10 μmol/L)共同处理进一步增加了醛固酮诱导的自噬体形成。Rg1(80 ng/mL)共同处理在早期有效减轻氧化应激并增加T-SOD活性,随后减少醛固酮处理的足细胞中的自噬。3-甲基腺嘌呤(3-MA,4 mmol/L)或N-乙酰半胱氨酸(NAC,50 mmol/L)共同处理对醛固酮诱导的足细胞自噬产生类似作用。
醛固酮增强体外足细胞中ROS的生成并促进自噬。人参皂苷Rg1有效减轻醛固酮诱导的氧化应激,从而间接抑制醛固酮诱导的足细胞自噬。