N-乙酰半胱氨酸对实验性慢性环孢素肾病小鼠 Klotho 表达及其信号通路的影响。

Influence of N-acetylcysteine on Klotho expression and its signaling pathway in experimental model of chronic cyclosporine nephropathy in mice.

机构信息

Transplant Research Center, Convergent Research Consortium in Immunologic Disease, The Catholic University of Korea, Seoul, Korea.

出版信息

Transplantation. 2013 Jul 27;96(2):146-53. doi: 10.1097/TP.0b013e318296c9a9.

DOI:10.1097/TP.0b013e318296c9a9

PMID:23765110

Abstract

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

NAC treatment preserves Klotho expression and modifies p-AKT/p-FoxO1 pathway in chronic CsA nephropathy.

摘要

背景

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。

方法

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。

结果

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。