Alpha-Ketoglutarate: A Metabolic Regulator of Cellular Homeostasis and Pathophysiology

Alpha-Ketoglutarate (AKG), a central intermediate of the tricarboxylic acid cycle, is a crucial metabolic and signaling molecule that connects mitochondrial function with cellular homeostasis, immunological modulation, epigenetic remodeling, and lifespan. While mitochondrial AKG maintains energy metabolism, the nuclear AKG pool influences chromatin remodeling through DNA and histone modifications, which together control hypoxia responses and shape gene expression patterns. This dual role demonstrates AKG's significance in mediating metabolic state, gene expression, and long-term cellular adaptability. AKG modulates immunological responses, reduces reactive oxygen species (ROS), promotes the polarization of anti-inflammatory macrophages, and suppresses nuclear factor kappa B (NF-κB) activation, thereby reducing chronic inflammatory processes. AKG restricts pro-inflammatory cytokine production, increases extracellular matrix synthesis, and reduces cartilage degradation in arthritic models, suggesting potential therapeutic benefits in autoimmune diseases and joint degeneration. Additionally, AKG affects lifespan in several model organisms, where supplementation enhances metabolic resilience, lowers age-related inflammation, modifies mTOR signaling, and preserves youthful epigenetic profiles. Additionally, because endogenous AKG levels decrease with age, oral supplementation of AKG, especially with calcium and arginine, has drawn attention to its potential benefits in longevity and metabolic health. Thus, AKG is versatile and has encouraging therapeutic promise for cancer, aging, and inflammatory illnesses. However, a lack of human clinical evidence prompts further research to determine ideal dosage, tissue selectivity, and long-term safety. The goal of this review is to critically examine the current mechanistic knowledge related to AKG biosynthesis and breakdown and its future implications in maintaining cellular homeostasis and controlling chronic inflammation.