Vitamin K2 Promotes Mitochondrial Structural and Functional Homeostasis to Ameliorate Alzheimer Pathology by...

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by β-amyloid (Aβ) accumulation and a breakdown of mitochondrial homeostasis. Vitamin K2 (VK2) has emerged as a potential neuroprotective agent, yet the specific molecular cascades linking its intervention to the restoration of mitochondrial integrity remain poorly understood. This study utilizes an AD Drosophila model to investigate the efficacy of VK2 and elucidates its multidimensional regulatory mechanisms. Behavioral analysis showed that VK2 significantly rescued locomotor impairments, improving both vertical climbing and horizontal walking performance. Crucially, VK2 intervention achieved a systemic rescue of mitochondrial health: transmission electron microscopy (TEM) confirmed the preservation of mitochondrial ultrastructure and cristae density, while biochemical assays demonstrated a robust recovery of bioenergetic markers, including ATP levels and the NAD⁺/NADH ratio. Furthermore, VK2 treatment stabilized the mitochondrial membrane potential (MMP) and effectively attenuated the accumulation of reactive oxygen species (ROS). To identify the molecular drivers of this recovery, an unbiased integration of human clinical transcriptomic data and network pharmacology prioritized the EGFR-Ras-ERK signaling axis as a central hub. In vivo validation confirmed that VK2 suppresses the pathological overactivation of this cascade. VK2 reduced EGFR phosphorylation in parallel with the effects observed for the EGFR inhibitor Gefitinib. Collectively, our findings show that VK2 ameliorates locomotor deficits and mitochondrial dysfunction in Aβ42-expressing flies and that these effects are associated with suppression of the EGFR-Ras-ERK signaling axis. Further studies are required to establish direct target engagement and pathway causality.