An Yu, Zhang Jian-zhao, Han Jing, Yang Hao-peng, Tie Lu, Yang Xiao-yuan, Xiaokaiti Yilixiati, Pan Yan, Li Xue-jun
State Key Laboratory of Natural & Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China.
Cell Physiol Biochem. 2013;32(5):1151-66. doi: 10.1159/000354515. Epub 2013 Nov 11.
BACKGROUND/AIMS: Acute kidney injury (AKI) is a major complication of kidney transplantation, resulting in early graft dysfunction. Since diuretic acetazolamide (AZA) has been shown to improve contrast induced AKI, we hypothesized that AZA also protected against ischemia-reperfusion (I/R) caused AKI.
An in vivo mouse renal I/R injury model and an in vitro H2O2 stimulated HK-2 cell injury model were utilized to examine the renoprotective effect of AZA. Renal injury and blood flow were measured. Nitric oxide synthase (eNOS)/Nitric oxide (NO), cell apoptosis and hypoxia-inducible factor-1α (HIF-1α) changes were analyzed.
AZA reduced kidney injury scores and improved renal function by decreasing serum creatinine and BUN levels after I/R. Impaired renal blood flow was restored by increasing eNOS activities and NO production, as indicated by Laser Doppler imaging. TUNEL staining presented that AZA reduced apoptotic cells due to attenuated caspase activation and increased Bcl-2/Bax ratio. Furthermore, HIF-1α induction by AZA was demonstrated. AZA also enhanced in vitro NO production, reduced cell apoptosis and increased HIF-1α expression. Knockdown of HIF-1α by RNAi confirmed that AZA exerted its protective role depending on HIF-1α. AZA's effects were significantly reduced by Akt inhibitor LY294002.
The present study demonstrated that AZA exerted a renoprotective role against I/R induced AKI through activating HIF-1α and downstream pathways.
背景/目的：急性肾损伤（AKI）是肾移植的主要并发症，可导致早期移植肾功能障碍。由于利尿剂乙酰唑胺（AZA）已被证明可改善造影剂诱导的AKI，我们推测AZA也能预防缺血再灌注（I/R）引起的AKI。
利用体内小鼠肾I/R损伤模型和体外H2O2刺激的HK-2细胞损伤模型来检测AZA的肾脏保护作用。测量肾损伤和血流量。分析一氧化氮合酶（eNOS）/一氧化氮（NO）、细胞凋亡和缺氧诱导因子-1α（HIF-1α）的变化。
I/R后，AZA通过降低血清肌酐和尿素氮水平降低了肾损伤评分并改善了肾功能。激光多普勒成像显示，通过增加eNOS活性和NO生成恢复了受损的肾血流量。TUNEL染色显示，AZA减少了凋亡细胞，这是由于半胱天冬酶激活减弱和Bcl-2/Bax比值增加所致。此外，还证实了AZA可诱导HIF-1α。AZA还增强了体外NO生成，减少了细胞凋亡并增加了HIF-1α表达。RNAi敲低HIF-1α证实AZA依赖HIF-1α发挥其保护作用。Akt抑制剂LY294002显著降低了AZA的作用。
本研究表明，AZA通过激活HIF-1α及其下游通路对I/R诱导的AKI发挥肾脏保护作用。
