PUBLICATION

Quantitative intravital imaging reveals in vivo dynamics of physiological-stress induced mitophagy

Authors
Wrighton, P.J., Shwartz, A., Heo, J.M., Quenzer, E.D., LaBella, K.A., Harper, J.W., Goessling, W.
ID
ZDB-PUB-210205-4
Date
2021
Source
Journal of Cell Science   134(4): (Journal)
Registered Authors
Goessling, Wolfram
Keywords
Autophagy, Fasting, Hypoxia, Lysosome, Mitochondria
MeSH Terms
  • Animals
  • Intravital Microscopy
  • Mitochondria
  • Mitophagy*
  • Stress, Physiological
  • Ubiquitin-Protein Ligases
  • Zebrafish*/genetics
PubMed
33536245 Full text @ J. Cell Sci.
Abstract
Mitophagy, the selective recycling of mitochondria through autophagy, is a crucial metabolic process induced by cellular stress, and defects are linked to aging, sarcopenia, and neurodegenerative diseases. To therapeutically target mitophagy, the fundamental in vivo dynamics and molecular mechanisms must be fully understood. Here, we generated mitophagy biosensor zebrafish lines expressing mitochondrially targeted, pH-sensitive, fluorescent probes mito-Keima and mito-EGFP-mCherry and used quantitative intravital imaging to illuminate mitophagy during physiological stresses-embryonic development, fasting and hypoxia. In fasted muscle, volumetric mitolysosome size analyses documented organelle stress-response dynamics, and time-lapse imaging revealed mitochondrial filaments undergo piecemeal fragmentation and recycling rather than the wholesale turnover observed in cultured cells. Hypoxia-inducible factor (Hif) pathway activation through physiological hypoxia or chemical or genetic modulation also provoked mitophagy. Intriguingly, mutation of a single mitophagy receptor bnip3 prevented this effect, whereas disruption of other putative hypoxia-associated mitophagy genes bnip3la (nix), fundc1, pink1 or prkn (Parkin) had no effect. This in vivo imaging study establishes fundamental dynamics of fasting-induced mitophagy and identifies bnip3 as the master regulator of Hif-induced mitophagy in vertebrate muscle.
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping