Degradation of engulfed mitochondria is rate-limiting in Optineurin-mediated mitophagy in neurons.

Journal Article (Journal Article)

Mitophagy, the selective removal of damaged mitochondria, is thought to be critical to maintain neuronal homeostasis. Mutations of proteins in the pathway cause neurodegenerative diseases, suggesting defective mitochondrial turnover contributes to neurodegeneration. In primary rat hippocampal neurons, we developed a mitophagy induction paradigm where mild oxidative stress induced low levels of mitochondrial damage. Mitophagy-associated proteins were sequentially recruited to depolarized mitochondria followed by sequestration into autophagosomes. The localization of these mitophagy events had a robust somal bias. In basal and induced conditions, engulfed mitochondria remained in non-acidified organelles for hours to days, illustrating efficient autophagosome sequestration but delayed lysosomal fusion or acidification. Furthermore, expression of an ALS-linked mutation in the pathway disrupted mitochondrial network integrity and this effect was exacerbated by oxidative stress. Thus, age-related decline in neuronal health or expression of disease-associated mutations in the pathway may exacerbate the slow kinetics of neuronal mitophagy, leading to neurodegeneration.

Full Text

Duke Authors

Cited Authors

  • Evans, CS; Holzbaur, EL

Published Date

  • January 14, 2020

Published In

Volume / Issue

  • 9 /

PubMed ID

  • 31934852

Pubmed Central ID

  • PMC6959996

Electronic International Standard Serial Number (EISSN)

  • 2050-084X

Digital Object Identifier (DOI)

  • 10.7554/eLife.50260

Language

  • eng

Conference Location

  • England