Muscle inflammation and MHC class I up-regulation in muscular dystrophy with lack of dysferlin: an immunopathological study.
ABSTRACT Muscle inflammation is characteristic of inflammatory myopathies but also occurs in muscular dystrophy with lack of the sarcolemmal protein dysferlin. We quantified inflammatory cells and major histocompatibility complex (MHC) expression in muscle from 10 patients with dysferlinopathy. Infiltrating cells were always present although numbers varied considerably; macrophages were more common than T cells, T cytotoxicity was absent, and MHC class I was overexpressed on muscle fibers. These findings differ from polymyositis (PM) but are closely similar to those in SJL/J mice (which lack dysferlin) and emphasize the relationship between absence of dysferlin and immune system abnormalities in muscle.
- Arthritis & Rheumatology 11/2012; · 7.48 Impact Factor
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ABSTRACT: Mutations in the dysferlin gene result in the development of a range of early adult-onset, progressive muscular dystrophies, collectively known as the dysferlinopathies. There is currently no effective treatment for these disorders. Several spontaneous and engineered alleles at the mouse dysferlin locus have been isolated and these dysferlin-deficient mouse strains are providing valuable insights into the role dysferlin plays in skeletal muscle physiology, heart function, and the regulation of the innate immune system. In addition, mouse models of dysferlinopathy are now widely used to test novel therapeutic strategies. Each dysferlin-deficient mouse strain has been characterised to varying degrees using a variety of histological and functional assays, occasionally producing results inconsistent with other strains. Here, we review each mouse model and physiological changes in various systems which accompany their muscle disease with emphasis on the how the disease process develops in different mouse models of dysferlinopathy. This review highlights the urgent requirement for standardised assays and outcome measures that will unify and coordinate research efforts throughout the field, procedures that are necessary if potential therapies are to be tested efficiently and effectively.Neuromuscular Disorders 03/2013; · 3.46 Impact Factor
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ABSTRACT: The review provides an update on the diagnosis of the main subtypes of inflammatory myopathies including dermatomyositis (DM), polymyositis (PM), necrotizing autoimmune myositis (NAM) and sporadic inclusion body myositis (sIBM). The fundamental aspects on muscle pathology and the unique pathomechanisms of each subset are outlined and the diagnostic dilemmas concerning the distinction of PM from sIBM and NAM are addressed. Dermatomyositis is a complement-mediated microangiopathy leading to destruction of capillaries, hypoperfusion and inflammatory cell stress on the perifascicular regions. NAM, is an increasingly recognized subacute myopathy triggered by statins, viral infections, cancer or autoimmuity with macrophages as the final effector cells causing fibre injury. In PM and sIBM cytotoxic CD8-positive T cells clonally expand in situ and invade major histocompatibility-I-expressing muscle fibres. The pathology of sporadic inclusion body myositis is complex because, in addition to the inflammatory mechanisms, there are degenerative features characterized by vacuolization and the accumulation of stressor and amyloid-related misfolded proteins. Inducible pro-inflammatory molecules, such as interleukin 1-β, may enhance the accumulation of stressor proteins. The principles for more effective treatment strategies are discussed.Neuropathology and Applied Neurobiology 04/2011; 37(3):226-42. · 4.84 Impact Factor