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Mosaic dysfunction of mitophagy in mitochondrial muscle disease

Takayuki Mito1, Amy E Vincent2, Julie Faitg2

  • 1Research Program of Stem Cells and Metabolism, Faculty of Medicine, Biomedicum Helsinki, University of Helsinki, 00290 Helsinki, Finland.

Cell Metabolism
|January 14, 2022
PubMed

Insights

Mitophagy, the removal of damaged mitochondria, is key in aging muscle. Its dysfunction contributes to age-related muscle diseases, but boosting mitophagy may offer therapeutic benefits.

Area of Science:

  • Cellular Biology
  • Mitochondrial Biology
  • Aging Research

Background:

  • Mitophagy is a crucial mitochondrial quality control process.
  • Its role in mammalian aging and pathophysiology is not fully understood.
  • Mitochondrial dysfunction is a hallmark of aging and various diseases.

Purpose of the Study:

  • To investigate the role of mitophagy in age-related skeletal muscle dysfunction.
  • To elucidate the mechanisms underlying mitochondrial pathology in aging.
  • To explore mitophagy as a potential therapeutic target.

Main Methods:

  • Analysis of mitophagy in skeletal muscle of aged mice and human patients.
  • Histological examination of muscle fibers and mitochondrial morphology.
  • Assessment of lysosomal homeostasis and mitochondrial turnover.
  • Investigating the effect of rapamycin on mitophagy.

Main Results:

  • Mitophagy is enhanced in early stages of age-related muscle pathology, particularly around central nuclei.
  • Progressive dysfunction leads to mitophagy arrest and disrupted lysosomal homeostasis.
  • Mitophagy exhibits mosaic, cell-autonomous regulation in adjacent muscle fibers.
  • Rapamycin treatment restored mitochondrial turnover, suggesting mTOR pathway involvement.

Conclusions:

  • Mitophagy is a significant feature of age-related mitochondrial pathology in mammalian muscle.
  • Mosaic mitophagy arrest contributes to respiratory chain deficiencies and mtDNA accumulation in aging and disease.
  • Enhancing mitophagy presents a promising therapeutic strategy for muscle mitochondrial dysfunction.
Keywords:
SBFSEMcentrally nucleated fiberslysosomemito-QCmitochondrial diseasemitochondrial myopathymitophagypatientragged-red fibers

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