Evaluation of mitochondrial bioenergetics, dynamics, endoplasmic reticulum-mitochondria crosstalk, and reactive oxygen species in fibroblasts from patients with complex I deficiency

Sci Rep. 2018 Jan 18;8(1):1165. doi: 10.1038/s41598-018-19543-3.


Mitochondrial complex I (CI) deficiency is the most frequent cause of oxidative phosphorylation (OXPHOS) disorders in humans. In order to benchmark the effects of CI deficiency on mitochondrial bioenergetics and dynamics, respiratory chain (RC) and endoplasmic reticulum (ER)-mitochondria communication, and superoxide production, fibroblasts from patients with mutations in the ND6, NDUFV1 or ACAD9 genes were analyzed. Fatty acid metabolism, basal and maximal respiration, mitochondrial membrane potential, and ATP levels were decreased. Changes in proteins involved in mitochondrial dynamics were detected in various combinations in each cell line, while variable changes in RC components were observed. ACAD9 deficient cells exhibited an increase in RC complex subunits and DDIT3, an ER stress marker. The level of proteins involved in ER-mitochondria communication was decreased in ND6 and ACAD9 deficient cells. |ΔΨ| and cell viability were further decreased in all cell lines. These findings suggest that disruption of mitochondrial bioenergetics and dynamics, ER-mitochondria crosstalk, and increased superoxide contribute to the pathophysiology in patients with ACAD9 deficiency. Furthermore, treatment of ACAD9 deficient cells with JP4-039, a novel mitochondria-targeted reactive oxygen species, electron and radical scavenger, decreased superoxide level and increased basal and maximal respiratory rate, identifying a potential therapeutic intervention opportunity in CI deficiency.

Publication types

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

MeSH terms

  • Acyl-CoA Dehydrogenases / deficiency
  • Acyl-CoA Dehydrogenases / genetics*
  • Adenosine Triphosphate / agonists
  • Adenosine Triphosphate / biosynthesis
  • Electron Transport / drug effects
  • Electron Transport / genetics
  • Electron Transport Complex I / deficiency*
  • Electron Transport Complex I / genetics
  • Endoplasmic Reticulum / drug effects
  • Endoplasmic Reticulum / metabolism
  • Endoplasmic Reticulum / pathology
  • Fibroblasts / drug effects
  • Fibroblasts / enzymology*
  • Fibroblasts / pathology
  • Free Radical Scavengers / pharmacology
  • Gene Expression
  • Humans
  • Membrane Potential, Mitochondrial / drug effects
  • Mitochondria / drug effects
  • Mitochondria / enzymology
  • Mitochondria / pathology
  • Mitochondrial Diseases / enzymology
  • Mitochondrial Diseases / genetics*
  • Mitochondrial Diseases / pathology
  • NADH Dehydrogenase / deficiency
  • NADH Dehydrogenase / genetics*
  • Nitrogen Oxides / pharmacology
  • Oxidative Phosphorylation / drug effects
  • Primary Cell Culture
  • Reactive Oxygen Species / antagonists & inhibitors
  • Reactive Oxygen Species / metabolism*


  • Free Radical Scavengers
  • JP4-039
  • NDUFV1 protein, human
  • Nitrogen Oxides
  • Reactive Oxygen Species
  • Adenosine Triphosphate
  • Acyl-CoA Dehydrogenases
  • ACAD9 protein, human
  • MT-ND6 protein, human
  • NADH Dehydrogenase
  • Electron Transport Complex I

Supplementary concepts

  • Mitochondrial complex I deficiency