Introduction: In Duchenne muscular dystrophy (DMD), the infiltration of skeletal muscle by immune cells aggravates disease, yet the precise mechanisms behind these inflammatory responses remain poorly understood. Chemotactic cytokines, or chemokines, are considered essential recruiters of inflammatory cells to the tissues.
Methods: We assayed chemokine and chemokine receptor expression in DMD muscle biopsies (n = 9, average age 7 years) using immunohistochemistry, immunofluorescence, and in situ hybridization.
Lymphotoxin beta (LTβ) regulates some inflammatory mechanisms that could be operative in idiopathic inflammatory myopathies (IM). We studied LTβ and LTβR in inflammatory myopathies, normal and disease controls with immunohistochemistry, Western blotting and in situ hybridisation. LTβ occurs in myonuclei of normal controls, implying its role in normal muscle physiology.
View Article and Find Full Text PDFThe idiopathic inflammatory myopathies (IM) represent a heterogeneous group of autoimmune diseases, of which dermatomyositis (DM), polymyositis (PM), and sporadic inclusion body myositis (IBM) are the most common. The crucial role played by tumor necrosis factor alpha (TNFα) in the IM has long been recognized. However, so far, 18 other members of the TNF superfamily have been characterized, and many of these have not yet received the attention they deserve.
View Article and Find Full Text PDFHeat shock proteins are important factors in skeletal muscle physiology and stress response. We examined the effects of chronic inflammation on the distribution of heat shock protein families 70 and 90 using immunofluorescence and Western blotting, in muscle biopsies from 33 idiopathic inflammatory myopathy patients [aged 26-66 (dermatomyositis), 17-78 (polymyositis) and 57-80 (sporadic inclusion body myositis) years], and seven Duchenne muscular dystrophy patients (aged 3-19 years). Our results reveal the multifaceted role played by chaperones in inflammatory muscle tissue.
View Article and Find Full Text PDFChaperones assist the metamorphosis of polypeptides to fully functional proteins. The family of heat shock proteins 70 (HSP70) bind at an early stage, while the HSP90 bind to proteins near their active conformation. We studied HSP90 and HSP70 in muscle biopsies from controls and patients diagnosed with the three main idiopathic inflammatory myopathies (IIM), namely dermatomyositis (DM), sporadic inclusion body myositis (IBM), and polymyositis (PM).
View Article and Find Full Text PDFThe transcription factor nuclear factor-kappaB (NF-kappaB) is a ubiquitously expressed protein family that is considered crucial in autoimmunity. We describe NF-kappaB p50 and p65, and the inhibitor I-kappaB alpha in the inflammatory exudates characteristic for the different idiopathic inflammatory myopathies (IIM), that is, endomysial CD8(+) cytotoxic T cells invading non-necrotic fibers in polymyositis (PM) and sporadic inclusion body myositis (sIBM), and the perimysial/perivascular CD20(+) B cells and CD4(+) T cells in dermatomyositis (DM). We also analyzed other inflammatory cells in the vicinity of active inflammation sites.
View Article and Find Full Text PDFCurr Opin Rheumatol
November 2009
Purpose Of Review: Cytokines and chemokines are essential players in the initiation and progression of the idiopathic inflammatory myopathies (IIMs). This review focuses on the most recent data and the new insight they provide for the disease mechanisms of dermatomyositis, polymyositis and sporadic inclusion body myositis.
Recent Findings: Interferon-alpha and beta are implicated in the innate immune responses underlying dermatomyositis, whereas interferon-gamma stands forward as a more general regulator of the IIMs, reflected by the induction of many interferon-gamma-inducible genes in patients.
The idiopathic inflammatory myopathies (IIM) comprise a heterogeneous group of muscle diseases. The three best-studied subgroups are dermatomyositis (DM), polymyositis (PM) and sporadic inclusion body myositis (IBM). The latter represents a steroid-refractory condition.
View Article and Find Full Text PDFSystemic manifestations of chronic obstructive pulmonary disease (COPD) include muscle wasting, and tumour necrosis factor alpha (TNFalpha) could represent a major inducer of these processes. We studied skeletal muscle histology in a murine model of cigarette smoke (CS)-induced COPD, comparing mice with different TNFalpha receptor genotypes. Muscles from hind limbs of wild type (WT), TNFalpha receptor 1 knockout (TNF alpha R1KO) and TNF alpha R2KO mice were prepared and weighed.
View Article and Find Full Text PDFThe idiopathic inflammatory myopathies (IIM) represent a heterogeneous group of acquired muscle diseases. The three best-studied subgroups: dermatomyositis (DM), polymyositis (PM), and sporadic inclusion body myositis (IBM), differ considerably both clinically and pathophysiologically. DM is a chiefly humoral endotheliopathy often associated with characteristic skin manifestations.
View Article and Find Full Text PDFThe idiopathic inflammatory myopathies (IM) are subdivided into dermatomyositis (DM), polymyositis (PM), and sporadic inclusion body myositis (IBM). These autoimmune muscle diseases represent different immunopathological entities. DM is a humoral endotheliopathy initiated by complement deposition in intramuscular blood vessels, and characterized by perimysial inflammation and muscle fiber atrophy in perifascicular regions.
View Article and Find Full Text PDFIn contrast with dermatomyositis and polymyositis, inclusion body myositis is unresponsive to glucocorticoid treatment. Glucocorticoid action is mediated through an active glucocorticoid receptor-alpha and negatively regulated by another glucocorticoid receptor isoform. In several autoimmune diseases glucocorticoid receptor-beta up-regulation is involved in glucocorticoid resistance.
View Article and Find Full Text PDFDrug News Perspect
November 2006
The inflammatory myopathies essentially comprise three diseases with different immunopathologic features. Dermatomyositis (DM) is a complement-mediated microangiopathy. The immune response in polymyositis (PM) and sporadic inclusion body myositis (IBM) is a CD8+ T-cell-mediated cellular reaction against an unknown muscle fiber antigen.
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