Mitochondrial homeostasis dysregulation: Potential mechanisms of Alzheimer's disease mediated by TDP-43.

Alzheimer's disease (AD) exhibits substantial clinical and pathological heterogeneity that is not fully explained by amyloid-β and tau pathology alone. TAR DNA-binding protein 43 (TDP-43) is increasingly recognized as a frequent copathology in AD, particularly in limbic regions, where its presence is associated with accelerated cognitive decline. Disruption of mitochondrial homeostasis is also an early and consistent feature of AD and contributes to neuronal vulnerability. In this review, we summarize current evidence linking TDP-43 pathology to impaired mitochondrial homeostasis in AD. We outline key features of mitochondrial homeostasis in neurons, review neuropathological and clinical data supporting the relevance of TDP-43 in AD, and synthesize emerging mechanisms by which TDP-43 may perturb mitochondrial homeostasis, including effects on expression, aggregation and localization, quality control, organelle dynamics, and endoplasmic reticulum-mitochondria communication.