Electron transport chain (ETC) dysfunction or hypoxia causes toxic NADH accumulation. How cells regenerate NAD⁺ under such conditions remains elusive. Here, integrating bioinformatic analysis and experimental validation, we identify glycerol-3-phosphate (Gro3P) biosynthesis as an endogenous NAD⁺-regeneration pathway. Under genetic or pharmacological ETC inhibition, disrupting Gro3P synthesis inhibits yeast proliferation, shortens lifespan of C. elegans, impairs growth of cancer cells in culture and in xenografts, and causes metabolic derangements in mouse liver. Moreover, the Gro3P shuttle selectively regenerates cytosolic NAD⁺ under mitochondrial complex I inhibition; enhancing Gro3P synthesis promotes shuttle activity to restore proliferation of complex I-impaired cells. Mouse brain has much lower levels of Gro3P synthesis enzymes as compared with other organs. Strikingly, enhancing Gro3P synthesis suppresses neuroinflammation and extends lifespan in the Ndufs4^−/− mice. Collectively, our results reveal Gro3P biosynthesis as an evolutionarily conserved coordinator of NADH/NAD⁺ redox homeostasis and present a therapeutic target for mitochondrial complex I diseases.

电子传输链 (ETC) 功能障碍或缺氧会导致有毒的 NADH 积累。在这种条件下细胞如何再生 NAD ^{+仍然难以捉摸。}在这里，结合生物信息学分析和实验验证，我们将 glycerol-3-phosphate (Gro3P) 生物合成确定为内源性 NAD ⁺ -再生途径。在遗传或药理学 ETC 抑制下，破坏 Gro3P 合成会抑制酵母增殖，缩短秀丽隐杆线虫的寿命，损害培养和异种移植物中癌细胞的生长，并导致小鼠肝脏代谢紊乱。此外，Gro3P 穿梭选择性地再生细胞溶质 NAD ⁺在线粒体复合物 I 抑制下；增强 Gro3P 合成可促进穿梭活动以恢复复杂 I 受损细胞的增殖。与其他器官相比，小鼠大脑的 Gro3P 合成酶水平要低得多。引人注目的是，增强 Gro3P 合成可抑制神经炎症并延长 Ndufs4 ^-/-小鼠的寿命。总的来说，我们的研究结果揭示了 Gro3P 生物合成作为 NADH/NAD ⁺氧化还原稳态的进化保守协调因子，并为线粒体复合物 I 疾病提供了治疗靶点。