Hepatic Gluconeogenesis and the Antidepressant Effects of Exercise: A Narrative Review

Background: Research indicates that hepatic gluconeogenesis mediates metabolic coupling between the liver and muscles via the Cori cycle and participates in liver-brain axis communication through its metabolic products and regulatory networks, thereby linking it to the pathogenesis of depression. Together, these mechanisms form the molecular basis for the antidepressant effects of exercise-regulated hepatic gluconeogenesis. Regular exercise promotes skeletal muscle contraction, causing the muscles to release more lactate into the circulatory system. Lactate acts as a substrate for gluconeogenesis and activates downstream signaling pathways, thereby enhancing the gluconeogenic response. During exercise, glycogenolysis directly provides energy, while lactate produced by glycolysis enters the liver via the Cori cycle to serve as a substrate for gluconeogenesis. By maintaining blood glucose homeostasis, this process ensures a stable energy supply to the brain, thereby improving cognitive and emotional functions. This study aims to elucidate how key substrates, regulatory factors, and rate-limiting enzymes involved in hepatic gluconeogenesis and exercise influence brain energy supply, cognitive function, and emotional regulation during depression. It seeks to identify the potential targets and mechanisms through which exercise exerts its antidepressant effects via hepatic gluconeogenesis, with the goal of providing a theoretical foundation for research into the mechanisms of depression and for clinical exercise interventions. Methods: This review conducted a comprehensive search of the recent literature on exercise, hepatic gluconeogenesis, and depression in major domestic and international databases. Adopting an interdisciplinary approach that integrates hepatic gluconeogenesis and exercise, it synthesizes existing evidence to explore the metabolic mechanisms by which exercise improves depression through the regulation of hepatic gluconeogenesis pathways. Results: Research has found that exercise may modulate hepatic gluconeogenic substrates and regulate the expression of cAMP-responsive element-binding protein in states of depression, regulatory factors such as liver kinase B1, forkhead box protein 01, hepatocyte nuclear factor 4 alpha, and peroxisome proliferator activated receptor gamma co activator factor 1 alpha are used to affect key rate limiting enzymes of hepatic gluconeogenesis, such as phosphoenolpyruvate carboxykinase and glucose-6-phosphatase, enhance hepatic gluconeogenesis processes, maintain blood glucose homeostasis, ensure brain energy supply, and improve depression. Conclusions: Exercise intervention targeting hepatic gluconeogenesis may be a potential therapeutic strategy for depression.