Calcium dysregulation, functional calpainopathy, and endoplasmic reticulum stress in sporadic inclusion body myositis

Calcium dysregulation, functional calpainopathy, and endoplasmic reticulum stress in sporadic inclusion body myositis

Sporadic inclusion body myositis (IBM) is the most common primary myopathy in the elderly, but its pathoetiology is still unclear. Perturbed myocellular calcium (Ca2+) homeostasis can exacerbate many of the factors proposed to mediate muscle degeneration in IBM, such as mitochondrial dysfunction, protein aggregation, and endoplasmic reticulum stress. Ca2+ dysregulation may plausibly be initiate...

Functional relevance of mitochondrial abnormalities in sporadic inclusion body myositis.

Cytochrome c oxidase (COX)-deficient fibers and multiple mitochondrial DNA (mtDNA) deletions are frequent findings in sporadic inclusion body myositis (s-IBM). However, the functional impact of these defects is not known. We investigated oxygen desaturation during exercise using the forearm exercise test, accumulation of lactate during exercise using a cycle ergometry test and mitochondrial cha...

Ongoing Developments in Sporadic Inclusion Body Myositis

Sporadic inclusion body myositis (IBM) is an acquired muscle disorder associated with ageing, for which there is no effective treatment. Ongoing developments include: genetic studies that may provide insights regarding the pathogenesis of IBM, improved histopathological markers, the description of a new IBM autoantibody, scrutiny of the diagnostic utility of clinical features and biomarkers, th...

Myouclear Breakdown in Sporadic Inclusion Body Myositis

Sporadic inclusion body myositis: a continuing puzzle.

There is now compelling evidence that sporadic inclusion body myositis (sIBM) is a muscle-specific autoimmune disease in which both T and B-cells play a part and in which both cytotoxic muscle fibre necrosis and degeneration occur. However the factors responsible for breakdown of immune tolerance and the nature of the target antigens expressed by muscle fibres remain unknown. Genetic factors ar...