Transplant Research Center, Convergent Research Consortium in Immunologic Disease, The Catholic University of Korea, Seoul, Korea.
Transplantation. 2013 Jul 27;96(2):146-53. doi: 10.1097/TP.0b013e318296c9a9.
Cyclosporine A (CsA)-associated oxidative stress has been proposed as an important mechanism of renal injury. This study was designed to examine whether N-acetylcysteine (NAC), a well-known antioxidant, affects Klotho, antiaging gene, expression and its signaling pathway in an experimental model of chronic CsA nephropathy.
Mice maintained on a low-sodium diet were given vehicle (olive oil, 1 mL/kg/day), CsA (30 mg/kg/day), NAC (150 mg/kg/day), or a combination of CsA and NAC for 4 weeks. The effect of NAC on CsA-induced renal injury was evaluated with basic parameters, histopathology, and markers of oxidative stress [8-hydroxy-2'-deoxyguanosine (8-OHdG) excretion and manganese superoxide dismutase (MnSOD) expression]. The influence of NAC on Klotho and its signal pathway (p-AKT and p-FoxO1) in CsA-treated mouse kidney was evaluated with immunohistochemistry and/or immunoblot.
Concomitant administration of CsA and NAC significantly improved renal function and attenuated tubulointerstitial fibrosis, and these changes were accompanied by decreased urinary 8-OHdG level and increased MnSOD expression. NAC treatment preserved Klotho gene expression compared with CsA treatment alone (P < 0.05), and this correlated with urinary 8-OHdG excretion (r = -0.934) and MnSOD expression (r = 0.873, P < 0.001 for both). Concomitant treatment of CsA and NAC translocated FoxO1 from the cytoplasm to the nucleus, implicating dephosphorylation of FoxO1 by NAC in p-AKT/p-FoxO1 pathway.
NAC treatment preserves Klotho expression and modifies p-AKT/p-FoxO1 pathway in chronic CsA nephropathy.
环孢素 A（CsA）相关的氧化应激被认为是肾损伤的重要机制。本研究旨在探讨 N-乙酰半胱氨酸（NAC），一种众所周知的抗氧化剂，是否会影响 Klotho 抗衰老基因在慢性 CsA 肾病的实验模型中的表达及其信号通路。
给予维持低钠饮食的小鼠 vehicle（橄榄油，1 mL/kg/天）、CsA（30 mg/kg/天）、NAC（150 mg/kg/天）或 CsA 和 NAC 的组合 4 周。用基本参数、组织病理学和氧化应激标志物[8-羟基-2'-脱氧鸟苷（8-OHdG）排泄和锰超氧化物歧化酶（MnSOD）表达]评估 NAC 对 CsA 诱导的肾损伤的影响。用免疫组化和/或免疫印迹法评估 NAC 对 CsA 处理的小鼠肾脏中 Klotho 及其信号通路（p-AKT 和 p-FoxO1）的影响。
同时给予 CsA 和 NAC 可显著改善肾功能并减轻肾小管间质纤维化，这些变化伴随着尿 8-OHdG 水平降低和 MnSOD 表达增加。与单独 CsA 处理相比，NAC 处理可保存 Klotho 基因表达（P<0.05），这与尿 8-OHdG 排泄（r=-0.934）和 MnSOD 表达（r=0.873，P<0.001）相关。同时给予 CsA 和 NAC 将 FoxO1 从细胞质转位到细胞核，提示 NAC 通过使 FoxO1 去磷酸化而影响 p-AKT/p-FoxO1 通路。
NAC 处理可保存慢性 CsA 肾病中的 Klotho 表达并调节 p-AKT/p-FoxO1 通路。
