Fluctuation-driven mechanotransduction regulates mitochondrial-network structure and function

Nat Mater. 2015 Oct;14(10):1049-57. doi: 10.1038/nmat4358. Epub 2015 Jul 27.

Abstract

Cells can be exposed to irregular mechanical fluctuations, such as those arising from changes in blood pressure. Here, we report that ATP production, assessed through changes in mitochondrial membrane potential, is downregulated in vascular smooth muscle cells in culture exposed to monotonous stretch cycles when compared with cells exposed to a variable cyclic stretch that incorporates physiological levels of cycle-by-cycle variability in stretch amplitude. Variable stretch enhances ATP production by increasing the expression of ATP synthase's catalytic domain, cytochrome c oxidase and its tyrosine phosphorylation, mitofusins and PGC-1α. Such a fluctuation-driven mechanotransduction mechanism is mediated by motor proteins and by the enhancement of microtubule-, actin- and mitochondrial-network complexity. We also show that, in aorta rings isolated from rats, monotonous stretch downregulates-whereas variable stretch maintains-physiological vessel-wall contractility through mitochondrial ATP production. Our results have implications for ATP-dependent and mechanosensitive intracellular processes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ATP Synthetase Complexes / metabolism
  • Adenosine Triphosphate / chemistry
  • Adolescent
  • Adult
  • Animals
  • Aorta / pathology
  • Catalytic Domain
  • Cattle
  • Electron Transport Complex IV / metabolism
  • GTP Phosphohydrolases / metabolism
  • Humans
  • Mechanotransduction, Cellular / physiology
  • Membrane Potentials
  • Middle Aged
  • Mitochondria / physiology*
  • Mitochondrial Membrane Transport Proteins / metabolism
  • Muscle, Smooth, Vascular / cytology
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Phosphorylation
  • Rats
  • Stress, Mechanical
  • Transcription Factors / metabolism
  • Tyrosine / chemistry
  • Young Adult

Substances

  • Mitochondrial Membrane Transport Proteins
  • PPARGC1A protein, human
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Transcription Factors
  • Tyrosine
  • Adenosine Triphosphate
  • Electron Transport Complex IV
  • ATP Synthetase Complexes
  • GTP Phosphohydrolases
  • Mfn1 protein, human