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Updated: May 24, 2025

Interactions with and Membrane Permeabilization of Brain Mitochondria by Amyloid Fibrils
Published on: September 28, 2019
Mitochondrial accumulation and lysosomal dysfunction result in mitochondrial plaques in Alzheimer's disease
Abstract:
Dysfunctional mitophagy is a key component of Alzheimer's disease (AD) pathology, yet direct in vivo evidence and mechanistic insights remain limited. Using a mitophagy reporter in an AD mouse model ( APP / PSEN1 /mt-Keima), we identified mitochondrial plaques (MPs) composed of accumulated mitochondria within or outside lysosomes in AD, but not normal mouse brains. Similar structures were also found in AD human brains, but not in healthy controls. Abnormal mitochondrial accumulation in dystrophic neurites, defective mitophagy, and impaired lysosomal function disrupted proper mitochondrial degradation, resulting in excessive mitochondria accumulation both within and outside autophagic vesicles. The resulting intensive mitochondria-containing neurites coalesce into MPs, which co-develop with amyloid plaques to form mixed plaques. These findings establish MPs as novel pathological entity and a promising therapeutic target in AD.
Insights
Researchers discovered mitochondrial plaques (MPs) in Alzheimer's disease (AD) brains. These MPs, containing accumulated mitochondria, represent a new pathological feature and potential therapeutic target for AD.
Area of Science:
- Neuroscience
- Cell Biology
- Pathology
Background:
- Dysfunctional mitophagy is implicated in Alzheimer's disease (AD) pathology.
- Direct in vivo evidence and mechanistic insights into mitophagy dysfunction in AD are limited.
Purpose of the Study:
- To investigate the role of mitophagy in AD pathogenesis using a mouse model.
- To identify and characterize novel pathological entities associated with AD.
Main Methods:
- Utilized a mitophagy reporter mouse model (APP/PSEN1/mt-Keima) for in vivo studies.
- Examined brain tissues from AD and control mice, as well as human AD and healthy control brains.
- Investigated mitochondrial accumulation, mitophagy, and lysosomal function.
Main Results:
- Identified "mitochondrial plaques" (MPs) composed of accumulated mitochondria in AD mouse and human brains, absent in controls.
- Observed abnormal mitochondrial accumulation in dystrophic neurites due to defective mitophagy and impaired lysosomal function.
- Found that MPs co-develop with amyloid plaques, forming mixed plaques.
Conclusions:
- Established mitochondrial plaques (MPs) as a novel pathological entity in Alzheimer's disease.
- Demonstrated that MPs result from disrupted mitochondrial degradation and accumulation.
- Highlighted MPs as a promising therapeutic target for AD intervention.
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