Iron deficiency-induced loss of skeletal muscle mitochondrial proteins and respiratory capacity; the role of mitophagy and secretion of mitochondria-containing vesicles

Pieter A. Leermakers, Alexander H. V. Remels, Marijke I. Zonneveld, Kasper M. A. Rouschop, Annemie M. W. J. Schols, Harry R. Gosker*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

18 Citations (Web of Science)

Abstract

Iron homeostasis is essential for mitochondrial function, and iron deficiency has been associated with skeletal muscle weakness and decreased exercise capacity in patients with different chronic disorders. We hypothesized that iron deficiency-induced loss of skeletal muscle mitochondria is caused by increased mitochondrial clearance. To study this, C2C12 myotubes were subjected to the iron chelator deferiprone. Mitochondrial parameters and key constituents of mitophagy pathways were studied in presence or absence of pharmacological autophagy inhibition or knockdown of mitophagy-related proteins. Furthermore, it was explored if mitochondria were present in extracellular vesicles (EV). Iron chelation resulted in an increase in BCL2/Adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) and BNIP3-like gene and protein levels, and the appearance of mitochondria encapsulated by lysosome-like vesicular structures in myotubes. Moreover, mitochondria were secreted via EV. These changes were associated with cellular mitochondrial impairments. These impairments were unaltered by autophagy inhibition, knockdown of mitophagy-related proteins BNIP3 and BNIP3L, or knockdown of their upstream regulator hypoxia-inducible factor 1 alpha. In conclusion, mitophagy is not essential for development of iron deficiency-induced reductions in mitochondrial proteins or respiratory capacity. The secretion of mitochondria-containing EV could present an additional pathway via which mitochondria can be cleared from iron chelation-exposed myotubes.

Original languageEnglish
Pages (from-to)6703-6717
Number of pages15
JournalFaseb Journal
Volume34
Issue number5
DOIs
Publication statusPublished - May 2020

Keywords

  • extracellular vesicles
  • mitochondrial clearance
  • myotubes
  • iron depletion
  • QUALITY-CONTROL
  • INDUCTION
  • AUTOPHAGY
  • ANEMIA
  • ENZYMES

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