Mitochondrial Dysfunction Identified as Central Hub Integrating Aβ/Tau Pathology, Neuroinflammation, and Neuronal Loss in Alzheimer's Disease

Alzheimer's disease (AD) is a complex and progressive neurodegenerative disorder, representing the most common cause of dementia globally. Its pathogenesis involves multi-level pathological alterations, yet a complete understanding of its underlying mechanisms remains elusive. Current therapeutic strategies often fall short in halting disease progression, highlighting the urgent need to identify core drivers and develop novel interventions. Mitochondrial dysfunction has emerged as a key factor in AD development, playing a central role in cellular energy metabolism, oxidative stress regulation, and synaptic health, making it a compelling area for mechanistic investigation.

Researchers conducted a comprehensive literature review, systematically synthesizing existing findings on mitochondrial involvement in Alzheimer's disease pathology. The analysis focused on elucidating the central role and multifaceted molecular mechanisms of mitochondrial dysfunction in AD progression. Key mechanistic pathways investigated included impaired energy metabolism, oxidative stress, synaptic damage, mitochondrial dynamics (fusion/fission), mitochondria-associated membranes (MAMs), mitophagy (mitochondrial quality control), and the bidirectional crosstalk within the gut-brain axis. This systematic approach aimed to integrate diverse findings into a cohesive understanding of mitochondrial contributions to AD.

The comprehensive analysis revealed several critical and interconnected mechanisms linking mitochondrial dysfunction directly to Alzheimer's disease progression. Firstly, impaired mitochondrial energy metabolism was identified, establishing a causal relationship with increased oxidative stress and subsequent synaptic injury. Secondly, dysregulation of mitochondrial fusion/fission dynamics was highlighted, particularly the aberrant interactions of amyloid-beta (Aβ) and hyper-phosphorylated tau (p-Tau) with the fission protein Drp1 and the channel protein VDAC1. Thirdly, significant dysfunction of mitochondria-associated membranes (MAMs) was observed, impacting lipid metabolism and calcium homeostasis. Fourthly, defective mitophagy, involving both the PINK1/Parkin pathway and receptor-mediated pathways, contributed to the accumulation of damaged mitochondria. Finally, bidirectional crosstalk between mitochondria and the gut-brain axis was identified as a significant contributor.

These interconnected pathways converge to amplify neuroinflammation and neuronal death, positioning mitochondrial dysfunction as a critical hub that integrates Aβ/Tau pathology, neuroinflammation, and neuronal loss, thereby perpetuating a self-sustaining vicious cycle in AD.