Complex III inhibition-induced pulmonary hypertension affects the mitochondrial proteomic landscape

Joel James, Mathews Valuparampil Varghese, Mikhail Vasilyev, Paul R. Langlais, Stevan P. Tofovic, Olga Rafikova, Ruslan Rafikov

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


The mitochondria play a vital role in controlling cell metabolism and regulating crucial cellular outcomes. We previously demonstrated that chronic inhibition of the mitochondrial complex III in rats by Antimycin A (AA) induced sustained pulmonary vasoconstriction. On the metabolic level, AA-induced mitochondrial dysfunction resulted in a glycolytic shift that was reported as the primary contributor to pulmonary hypertension pathogenesis. However, the regulatory proteins driving this metabolic shift with complex III inhibition are yet to be explored. Therefore, to delineate the mechanisms, we followed changes in the rat lung mitochondrial proteome throughout AA treatment. Rats treated with AA for up to 24 days showed a disturbed mitochondrial proteome with significant changes in 28 proteins (p < 0.05). We observed a time-dependent decrease in the expression of key proteins that regulate fatty acid oxidation, the tricarboxylic acid cycle, the electron transport chain, and amino acid metabolism, indicating a correlation with diminished mitochondrial function. We also found a significant dysregulation in proteins that controls the protein import machinery and the clearance and detoxification of oxidatively damaged peptides via proteolysis and mitophagy. This could potentially lead to the onset of mitochondrial toxicity due to misfolded protein stress. We propose that chronic inhibition of mitochondrial complex III attenuates mitochondrial function by disruption of the global mitochondrial metabolism. This potentially aggravates cellular proliferation by initiating a glycolytic switch and thereby leads to pulmonary hypertension.

Original languageEnglish (US)
Article number5683
Pages (from-to)1-14
Number of pages14
JournalInternational journal of molecular sciences
Issue number16
StatePublished - Aug 2 2020


  • Complex III
  • Fatty acid metabolism
  • Metabolic dysfunction
  • Mitochondria
  • Pulmonary arterial hypertension

ASJC Scopus subject areas

  • Catalysis
  • Molecular Biology
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry


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