Dystrophic neurites of senile plaques in Alzheimer's disease are deficient in cytochrome c oxidase

E Pérez-Gracia, B Torrejón-Escribano, I Ferrer - Acta neuropathologica, 2008 - Springer
E Pérez-Gracia, B Torrejón-Escribano, I Ferrer
Acta neuropathologica, 2008Springer
Double-labeling immunofluorescence and confocal microscopy have been used to learn
about the local relationship between amyloid, mitochondria, and cytochrome c oxidase
(COX) in dystrophic neurites of senile plaques in the frontal cortex in Alzheimer's disease
(AD). Dystrophic neurites surrounding amyloid plaques are filled with mitochondrial porin-
immunoreactive structures. In contrast with tangle-bearing and non-tangle-bearing neurons,
which express mitochondrial porin and COX subunit 4, porin-immunoreactive neurites of …
Abstract
Double-labeling immunofluorescence and confocal microscopy have been used to learn about the local relationship between amyloid, mitochondria, and cytochrome c oxidase (COX) in dystrophic neurites of senile plaques in the frontal cortex in Alzheimer's disease (AD). Dystrophic neurites surrounding amyloid plaques are filled with mitochondrial porin-immunoreactive structures. In contrast with tangle-bearing and non-tangle-bearing neurons, which express mitochondrial porin and COX subunit 4, porin-immunoreactive neurites of senile plaques lack COX subunit 4. Parallel western blot studies in mitochondria-enriched fractions of the frontal cortex in the same cases disclosed reduced expression levels of COX, but not of prohibitin, in AD stages VB/C of Braak. Co-localization of porin and lysosomal associated protein 1, as revealed by double-labeling immunofluorescence and confocal microscopy, suggests that mitochondria may be engulfed by lysosomes in dystrophic neurites. These findings support a local link between amyloid deposition, abnormal mitochondria and impaired respiratory chain function (resulting from decrease of COX expression) in dystrophic neurites of senile plaques in AD.
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