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Ultrastructural Changes in Skeletal Muscle of Infants with Mitochondrial Respiratory Chain Complex I Defects

Ji Young Mun1, Min Kyo Jung2, Se Hoon Kim3

  • 1Department of Biomedical Laboratory Science, College of Health Sciences, Eulji University, Seongnam, Korea.

Journal of Clinical Neurology (Seoul, Korea)
|September 9, 2017
PubMed

Insights

Infants with mitochondrial disease (MD) and defects in mitochondrial respiratory chain complex I (MRC I) show distinct skeletal muscle ultrastructural changes. These findings may help in detecting MD in infants.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Pediatric Neurology

Background:

  • Mitochondrial disease (MD) pathogenesis involves disrupted cellular energy metabolism due to mitochondrial respiratory chain complex (MRC) defects.
  • Infants with unexplained neurodegenerative symptoms or myopathies are often evaluated for MD.

Purpose of the Study:

  • To investigate ultrastructural changes in skeletal muscle of infants with MRC I defects.
  • To determine if specific morphological alterations correlate with MRC I dysfunction.

Main Methods:

  • Muscle biopsies from 12 infants suspected of MD were analyzed.
  • Biochemical enzyme assays were performed to identify MRC defects.
  • Transmission electron microscopy was used to examine skeletal muscle ultrastructure.

Main Results:

  • MRC I defects were confirmed in 7 out of 12 infants.
  • Skeletal muscles of affected infants displayed larger mitochondria.
  • Accumulation of lipid droplets and unique fused structures were observed.

Conclusions:

  • Mitochondrial functional defects in MRC I impair adenosine triphosphate synthesis, leading to skeletal muscle alterations.
  • Observed ultrastructural changes may serve as diagnostic markers for MD in infants.
Abstract

Keywords:
infantmitochondriamuscle pathologyrespiratory chain complextransmission electron microscopyultrastructure

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