衰老相关肥胖和代谢下降的新调控分子GSNOR的发现及机制研究

Aging-associated obesity and metabolic decline are high risk factors of aging related diseases and effective control of the "Middle-aged fat" is a key factor to control aging-related metabolic disorders. Our early study showed that the aging related metabolic disorder phenotypes, such as weight increase, fat accumulation, basal metabolic rate reduction, insulin resistant, were effectively controlled in the GSNOR (the key enzyme S-nitrosoglutathione reductase, regulation of nitric oxide metabolism and protein S-nitrosation) knockout mice. These results suggested that GSNOR may be a key molecule for healthy aging. Based this original discovery, this project will focus on the key scientific question that how GSNOR influences the aging associated obesity and metabolic decline. This project will determine the function of GSNOR in aging-associated obesity and metabolic decline by specific knockout or overexpression GSNOR FloxP mice in fat. Furthermore, to reveal the GSNOR regulated molecular mechanism and cell signaling pathway in Aging-associated obesity and metabolic decline by S-nitrosation modification quantitative proteomics and protein-protein interaction assay. GSNOR specific inhibitors will be screened and the function will be confirmed in aging related metabolic disorder model. This study will not only provide new target and new strategy for the control of aging-associated obesity and metabolic decline, but will also reveal new molecular mechanisms of this process, providing a scientific basis for the realization of healthy aging.

衰老相关代谢肥胖和代谢下降是衰老及其相关疾病的高风险因素，有效控制“中年发福”是健康衰老的重要基础。申请人课题组发现，小鼠自然衰老模型中体重增加、脂肪积累、基础代谢率降低等表型在GSNOR（S-nitrosoglutathione reductase，调控一氧化氮代谢及蛋白质巯基亚硝基化修饰的关键酶）敲除小鼠中均得到有效控制。本项目拟基于该原始发现，围绕“GSNOR是如何影响衰老相关肥胖和代谢降低”关键科学问题，利用脂肪特异性敲除和过表达GSNOR的FloxP转基因小鼠研究GSNOR在衰老相关肥胖和代谢下降中的作用和细胞信号通路调控机制，通过蛋白质亚硝基化修饰定量组学等揭示GSNOR作用的分子机制，并进行GSNOR特异小分子抑制剂的筛选和效应验证。本研究将发现组织器官衰老的新靶点和衰老相关代谢失调的新机制，为控制衰老相关肥胖和代谢下降提供新策略。

衰老相关代谢肥胖和代谢下降是衰老及其相关疾病的高风险因素，有效控制“中年发福” 是健康衰老的重要基础。本项目主要是研究蛋白质亚硝基化调控关键蛋白GSNOR（S-nitrosoglutathione reductase）在衰老相关肥胖和代谢下降中的作用和机制。我们发现自然衰老的小鼠皮下脂肪中GSNOR显著升高，进一步构建了GSNOR全身敲除小鼠、脂肪组织特异过表达小鼠，代谢表型分析确定了GSNOR是导致衰老肥胖和代谢失调的关键分子。通过定量蛋白质亚硝基化组学分析发现自噬关键蛋白Beclin-1是GSNOR的重要靶点，脂肪中GSNOR高表达使Beclin-1的351位半胱氨酸亚硝基化水平降低，导致Beclin-1 第90位丝氨酸的磷酸化水平升高，Beclin-1活性升高，细胞自噬增加，线粒体数量降低，使皮下脂肪米色化维持能力降低，白色化增加，从而导致代谢下降。进一步，我们构建了亚硝基化位点突变的Beclin-1C351A小鼠，发现该小鼠Beclin-1活性显著升高、自噬增加、代谢下降，皮下脂肪米色化维持能力差。本研究确定了GSNOR 是调控衰老相关肥胖和代谢下降的新关键分子，揭示了 GSNOR 通过调控自噬关键蛋白Beclin-1的亚硝基化修饰调控脂肪白色化，从而调控衰老相关肥胖和代谢下降的分子机制。研究结果揭示了衰老相关肥胖和代谢失调的新靶点及新分子机制，为有效控制“中年发福”提供了新思路。此外，我们还拓展了精准氧化还原调控衰老机制的研究，提出了抗氧化抗衰老的新概念和新理念。