Autophagy in Alzheimer's Disease: Mechanisms, Clinical Trials, and Horizons

Alzheimer's disease (AD) is an incurable progressive neurodegenerative disorder characterized by the pathological accumulation of amyloid beta (Aβ) plaques and neurofibrillary tangles in the brain. Recent findings have identified dysregulation of autophagy, a cellular mechanism for degradation and recycling, as a crucial contributor to the pathogenesis of AD. This narrative review examines the role of autophagy in the metabolism of Aβ and tau and evaluates current therapeutic strategies aimed at modulating autophagic pathways.

Autophagy is governed by the key molecular regulators mammalian target of rapamycin, adenosine monophosphate-activated protein kinase, Beclin-1, and transcription factor EB, which collectively control the clearance of protein recycling, including aggregates, inside cells. Pharmacological agents such as rapamycin, resveratrol, and trehalose, alongside sigma-1 receptor agonists and gene therapy approaches, have demonstrated potential in modulating autophagy in preclinical and clinical studies. Despite these advances, significant challenges persist, namely, neuronal heterogeneity, optimal timing for therapeutic intervention, and the absence of reliable biomarkers to monitor autophagic activity and treatment efficacy.

Targeting autophagy offers a promising and potentially safe avenue for slowing AD progression. Future investigations should prioritize the development of selective autophagy modulators and personalized treatment strategies to restore autophagic flux and enhance clinical outcomes in patients with AD.