Format

Send to

Choose Destination
Neuromuscul Disord. 2019 Mar;29(3):242-246. doi: 10.1016/j.nmd.2019.02.001. Epub 2019 Feb 10.

Mitochondrial DNA depletion in sporadic inclusion body myositis.

Author information

1
Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway.
2
Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway; Department of Clinical Medicine (K1), University of Bergen, Pb 7804, 5020, Norway.
3
Department of Clinical Medicine (K1), University of Bergen, Pb 7804, 5020, Norway.
4
Department of Pathology, Haukeland University Hospital, Bergen, 5021, Norway; Department of Biomedicine, University of Bergen, Bergen, Pb 7804, 5020, Norway.
5
Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway; Department of Clinical Medicine (K1), University of Bergen, Pb 7804, 5020, Norway. Electronic address: laurence.bindoff@nevro.uib.no.

Abstract

Sporadic inclusion body myositis (sIBM) is a late onset disorder of unkown aetiology. Mitochondrial changes such as cytochrome oxidase deficient fibres are a well recognised feature and mitochondrial DNA (mtDNA) deletions have also been reported, but not consistently. Since mtDNA deletions are not present in all cases, we investigated whether other types of mtDNA abnormality were responsible for the mitochondrial changes. We studied 9 patients with sIBM. To control for fibre loss or replacement with inflammatory cells, we compared sIBM patients with necrotising myopathy (n = 4) as well as with healthy controls. Qualitative anlysis for mtDNA deletions and quantitative measurement of mtDNA copy number showed that muscle from patients with sIBM contained on average 67% less mtDNA than healthy controls (P = 0.001). The level of mtDNA was also significantly depleted in sIBM when compared to necrotising myopathy. No significant difference in copy number was seen in patients with necrotising myopathy compared to controls. Deletions of mtDNA were present in 4 patients with sIBM, but not all. Our findings suggest that mtDNA depletion is a more consistent finding in sIBM, and one that may be implicated in the pathogenesis of the disease.

KEYWORDS:

Mitochondrial DNA deletion; Mitochondrial DNA depletion; Necrotising myopathy; Sporadic inclusion body myositis

PMID:
30850168
DOI:
10.1016/j.nmd.2019.02.001

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center