RESUMO
BACKGROUND/AIM: To investigate the contribution of muscle tissue-derived cytokines in dermatomyositis (DM). MATERIALS AND METHODS: Muscle homogenates were prepared from deltoid muscle biopsy specimens of 10 patients with DM and eight controls with no pathological signs of myopathy. Interleukin (IL)-4, interferon (IFN)-γ and IL-17 levels were evaluated by enzyme-linked immunosorbent assay (ELISA) and immunoblotting analysis. Muscle strength grades were recorded. RESULTS: Patients with DM showed significantly elevated muscle tissue IL-4 and IFN-γ levels, whereas IL-17 levels were comparable between patients with DM and controls. Immunoblotting studies confirmed ELISA results. In DM muscle specimens, IL-4 and IFN-γ levels were positively correlated, while no correlation was observed between IL-17 and the other two cytokines. Moreover, IL-4 and IFN-γ levels were significantly negative correlated with muscle strength grades for the deltoid muscle. CONCLUSION: Our results confirm the involvement of T helper (Th) 1-type and Th2-type immunity in DM pathogenesis. Muscle tissue appears to contribute to muscle weakness in DM by producing inflammatory cytokines.
Assuntos
Dermatomiosite/genética , Interferon gama/genética , Interleucina-17/genética , Interleucina-4/genética , Adulto , Idoso , Biópsia , Músculo Deltoide/metabolismo , Músculo Deltoide/patologia , Dermatomiosite/patologia , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação da Expressão Gênica , Humanos , Inflamação/genética , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Músculos/metabolismo , Músculos/patologiaRESUMO
AIM: Muscle specific kinase (MuSK) antibody-positive myasthenia gravis(MG) patients might present with clinical and electrophysiological signs of muscle atrophy. In this study, we investigated the potential contribution of mitochondrial dysfunction to muscle atrophy induced by MuSK immunity. METHODS: Mitochondrial enzyme expression was investigated in muscle samples of MuSK-immunized, acetylcholine receptor (AChR)-immunized, and complete Freund's adjuvant (CFA)-immunized C57BL/6 (B6) mice using histochemical methods. Mitochondrial enzyme activity was also investigated in MuSK- and CFA-immunized mice. RESULTS: Histochemical analysis showed normal muscle fiber activity on succinate dehydrogenase (SDH) and cytochrome oxidase (COX) stains in all immunization groups. However, MuSK-immunized mice had more ragged-red fibers on modified Gomori-trichrome (MGT) stain and more pronounced type 1 muscle fiber atrophy. MuSK-immunized mice also showed reduced citrate synthase, SDH, and NADH-cytochrome c-reductase activity. DISCUSSION: Our results suggest that MuSK-immunity might induce muscle atrophy through mitochondrial dysfunction.
Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias/enzimologia , Doenças Musculares/enzimologia , Miastenia Gravis/enzimologia , Fosfotransferases/imunologia , Succinato Desidrogenase/metabolismo , Animais , Autoanticorpos/imunologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BLRESUMO
Mutations of the parkin gene on chromosome 6 cause early-onset parkinsonism. Myopathy has not been reported to be a feature of this condition. Here we report the muscle biopsy findings of a 53-year-old man with a novel parkin gene mutation (IVS-9-1 deletion). His symptoms were characterized by typical early-onset, dopa-responsive, and slowly progressive parkinsonism. Parkin gene analysis revealed a homozygous IVS-9-1 deletion in the proband and his sibling. The unusual feature was hypertrophy of bilateral thigh muscles in the proband. Muscle biopsy from the biceps brachii muscle showed abundant cytochrome oxidase (COX) (-) fibers. This is the first report on the coexistence of a myopathy with COX deficiency with parkin disease and may shed light on the function of parkin in muscle.
