SIRT1去乙酰化修饰对慢性心衰大鼠肾功能及AQP2表达的调节机制及运动干预

The morbidity of chronic heart failure (CHF) is growing year by year, and has become the most focus question in worldwide. Water retention caused by renal dysfunction is one of the most important pathophysiological changes in CHF. The aquaporins (AQPs; a family of water channel proteins), and in particular AQP-2, play a major role in water reabsorption in the renal medulla collecting duct. Recent studies indicated that acetylation is one of the important ways of regulating renal dysfunction. Sirtuin 1(SIRT1) belongs to a highly conserved family of nicotinamida adenine dinucleotide (NAD+)-dependent histone deacetylase. Therefore, we hypothesize that SIRT1 regulate renal dysfunction by deacetylating its target proteins during chronic heart failure. Based on the previous study, we study the effects of SIRT1 on the expression of renal AQP2 are directly or by deacetylating NF-κB in renal collecting duct epithelial cell. Further we determine whether the intermittent aerobic exercise represents a safe, useful and effective therapy for improving renal dysfunction in CHF rats, and the underlying mechanism may be related to the regulation of SIRT1 on the expression of AQP2. The study not only provides new theoretical bases for the regulation of acetylation on renal dysfunction in CHF, but also lays the foundation for clinical application of exercise therapy for CHF.

慢性心力衰竭（CHF）发病率逐年增长，已成为世界范围内最受关注的健康问题。肾脏功能异常导致的水潴留是CHF最重要的病理生理变化之一。肾脏水通道蛋白家族，尤其是水通道蛋白2(AQP2)在肾脏水重吸收中起着关键性作用。新近发现：乙酰化修饰是调节肾脏功能紊乱的重要方式之一。因此，我们假设SIRT1的去乙酰化修饰对CHF时肾脏功能紊乱有调控作用。本项目在前期工作基础上，运用肾脏集合管主细胞，通过SIRT1对肾脏水潴留的影响和机制研究，揭示SIRT1去乙酰化修饰对CHF中肾脏AQP2表达是直接作用或是通过核转录因子NF-κB等进行调控；运用CHF大鼠，通过运动刺激干预手段，确定间歇有氧运动对改善CHF大鼠肾功能的安全性和有效性；阐明间歇有氧运动是否通过SIRT1调节AQP2及其分子机制。该研究不仅为乙酰化修饰对CHF中肾功能紊乱的调节提供依据，而且为CHF运动疗法临床应用奠定实验基础。

通过构建心肌梗死（MI）大鼠模型，给予间歇运动干预，采用心功能测试、免疫组化、免疫荧光、Western Blot、qRT-PCR和ELISA等技术方法，对大鼠心电图和血流动力学指标，心梗后肾脏中AQP2、SIRT1、miR-21、miR-34a、炎症因子和肾脏损伤标志物等指标进行检测。结果证实间歇运动上调miR-21，激活SIRT1-NF-κB信号通路，抑制肾脏水潴留、炎症反应和间质纤维沉积，保护肾脏功能。miR-34a在间歇运动保护心梗后肾脏损伤中的作用及机制研究正在进行。.体外原代培养肾脏内髓集合管细胞，模拟体内环境给与炎症刺激，对炎症条件下肾脏集合管细胞中的上述指标进行检测。通过基因过表达、RNA干扰、microRNA 过表达或抑制等技术，探讨了miR-21对肾脏集合管细胞中AQP2、炎症因子等表达的影响及调控机制。证实炎症导致肾脏细胞功能紊乱，诱发水潴留，miR-21通过激活SIRT1-NF-κB通路参与炎症条件下肾脏集合管细胞的功能调控。.综上所述，有氧运动可诱导肾脏局部miR-21表达升高，激活其下游信号通路SIRT1-NF-κB，减缓MI大鼠肾脏水潴留和炎症反应，改善肾功能。 项目资助发表SCI论文2篇，ESCI论文1篇，核心论文1篇，另有2篇论文正在投稿修改。