Affordable Access

Human skeletal muscle cytosols are refractory to cytochrome c-dependent activation of type-II caspases and lack APAF-1.

Authors
  • Burgess, D H
  • Svensson, M
  • Dandrea, T
  • Grönlund, K
  • Hammarquist, F
  • Orrenius, S
  • Cotgreave, I A
Type
Published Article
Journal
Cell Death and Differentiation
Publisher
Springer Nature
Publication Date
Mar 01, 1999
Volume
6
Issue
3
Pages
256–261
Identifiers
PMID: 10200576
Source
Medline
License
Unknown

Abstract

Apoptotic regulatory mechanisms in skeletal muscle have not been revealed. This is despite indications that remnant apoptotic events are detected following exercise, muscle injury and the progression of dystrophinopathies. The recent elicitation of a cytochrome c-mediated induction of caspases has led to speculation regarding a cytochrome c mechanism in muscle. We demonstrate that cytosols from skeletal muscle biopsies from healthy human volunteers lack the ability to activate type-II caspases by a cytochrome c-mediated pathway despite the confirmed presence of both procaspase-3 and -9. This was not due to the presence of an endogenous inhibitor, as the muscle cytosols enhanced caspase activity when added to a control cytosol, subsequently activated by cytochrome c and dATP. In addition, we demonstrate that muscle cytosols lack the apoptosis protease activator protein-1 (APAF-1), both at the protein and mRNA levels. These data indicate that human skeletal muscle cells will be refractory to mitochondrial-mediated events leading to apoptosis and thus can escape a major pro-apoptotic regulatory mechanism. This may reflect an evolutionary adaptation of cell survival in the presence of the profusion of mitochondria required for energy generation in motility.

Report this publication

Statistics

Seen <100 times