肝臟NADH還原應激是代謝性狀常見變異的基礎
作者:
小柯機器人發布時間:2020/5/29 13:07:44
近日,美國哈佛醫學院Vamsi K. Mootha研究團隊發現,肝臟NADH還原應激是代謝性狀常見變異的基礎。2020年5月27日,《自然》雜誌在線發表了這項成果。
研究人員發現,在體內應用的乳酸短桿菌(Lb)NOX1,這是一種細菌中產生水的NADH氧化酶,能夠用於評估直接降低小鼠肝細胞內NADH/NAD+比例的代謝後果。通過將這種遺傳工具與代謝組學相結合,研究人員將循環α-羥基丁酸酯水平鑑定為肝細胞NADH/NAD+比升高(也稱為還原性應激)的標誌。
在人類中,循環α-羥基丁酸酯水平的升高以前與葡萄糖耐量降低、胰島素抵抗和線粒體疾病相關,並與GCKR5中常見的遺傳變異相關,這以突變也與許多看似不同的代謝性狀相關。使用LbNOX,研究人員證明了NADH還原應激介導GCKR變化對許多代謝性狀的影響,包括循環甘油三酸酯水平、葡萄糖耐受量和FGF21水平。
這項工作將肝臟NADH/NAD+比例的升高鑑定為潛在的代謝參數,這一參數由人類遺傳變異決定,並對關鍵的代謝特徵和疾病起因果關係。此外,它還強調了LbNOX等遺傳工具在「因果性代謝」研究中的作用。
據悉,細胞內NADH/NAD+比例是生物化學的基礎,但人們對其在體內代謝所貢獻的程度(反應還是驅動)卻知之甚少。
附:英文原文
Title: Hepatic NADH reductive stress underlies common variation in metabolic traits
Author: Russell P. Goodman, Andrew L. Markhard, Hardik Shah, Rohit Sharma, Owen S. Skinner, Clary B. Clish, Amy Deik, Anupam Patgiri, Yu-Han H. Hsu, Ricard Masia, Hye Lim Noh, Sujin Suk, Olga Goldberger, Joel N. Hirschhorn, Gary Yellen, Jason K. Kim, Vamsi K. Mootha
Issue&Volume: 2020-05-27
Abstract: The cellular NADH/NAD+ ratio is fundamental to biochemistry, but the extent to which it reflects versus drives metabolic physiology in vivo is poorly understood. Here we report the in vivo application of Lactobacillus brevis (Lb)NOX1, a bacterial water-forming NADH oxidase, to assess the metabolic consequences of directly lowering the hepatic cytosolic NADH/NAD+ ratio in mice. By combining this genetic tool with metabolomics, we identify circulating α-hydroxybutyrate levels as a robust marker of an elevated hepatic cytosolic NADH/NAD+ ratio, also known as reductive stress. In humans, elevations in circulating α-hydroxybutyrate levels have previously been associated with impaired glucose tolerance2, insulin resistance3 and mitochondrial disease4, and are associated with a common genetic variant in GCKR5, which has previously been associated with many seemingly disparate metabolic traits. Using LbNOX, we demonstrate that NADH reductive stress mediates the effects of GCKR variation on many metabolic traits, including circulating triglyceride levels, glucose tolerance and FGF21 levels. Our work identifies an elevated hepatic NADH/NAD+ ratio as a latent metabolic parameter that is shaped by human genetic variation and contributes causally to key metabolic traits and diseases. Moreover, it underscores the utility of genetic tools such as LbNOX to empower studies of 『causal metabolism』.
DOI: 10.1038/s41586-020-2337-2
Source: https://www.nature.com/articles/s41586-020-2337-2