Project description:Expression profiling of human myositis muscle samples This study was designed to compare expression signatures among the various types of inflammatory myopathy, dermatomyositis (DM), inclusion body myositis (IBM), necrotizing myopathy (NM), nonspecific myopathy (NS), and polymyositis (PM) compared to normal (NL) muscle.
Project description:Immune cell infiltration in myositis were by examining microarray expression profiles in muscle biopsies from 31 myositis patients and 5 normal controls. Muscle samples from 36 subjects (5 normal controls, 5 NM, 8 DM, 8 PM and 10 IBM) were studied
Project description:Microarray data from muscle biopsy specimens from subjects with inclusion body myositis, polymyositis, and normals Keywords: Research study
Project description:Microarray data from muscle biopsy specimens from subjects with inclusion body myositis, polymyositis, and normals Experiment Overall Design: Microarray experiments
Project description:Immune cell infiltration in myositis were by examining microarray expression profiles in muscle biopsies from 31 myositis patients and 5 normal controls.
Project description:Idiopathic inflammatory myopathies (polymyositis and dermatomyositis) are heterogeneous group of muscle disorders of unknown etiology.The pathogenic pathways responsible for muscle fiber damage and dysfunction in myositis are not currently well defined. Identification of such pathways may help to design novel therapeutic interventions and also help to develop diagnostic tests. Experiment Overall Design: Muscle biopsies from a separate group of 5 adult untreated female DM patients were profiled and compared to muscle tissue of normal human healthy volunteers to define molecular pathways in muscle of myositis patients. Confirm and map key pathway members to specific cell types in the muscle tissue of patients and controls using RT-PCR, Western blotting and Immunolocalization.
Project description:Idiopathic inflammatory myopathies (polymyositis and dermatomyositis) are heterogeneous group of muscle disorders of unknown etiology.The pathogenic pathways responsible for muscle fiber damage and dysfunction in myositis are not currently well defined. Identification of such pathways may help to design novel therapeutic interventions and also help to develop diagnostic tests. Keywords: Development or differentiation design
Project description:Complement proteins are deposited in the muscles of patients with myositis. However, the local expression and regulation of complement genes within myositis muscle have not been well characterized. In this study, bulk RNA sequencing (RNAseq) analyses of muscle biopsy specimens revealed that complement genes are locally overexpressed and correlate with markers of myositis disease activity, including the expression of interferon-gamma (IFN )-induced genes. Single cell and single nuclei RNAseq analyses showed that most local expression of complement genes occurs in macrophages, fibroblasts, and satellite cells, with each cell type expressing different sets of complement genes. Biopsies from immune-mediated necrotizing myopathy patients, who have the lowest levels of IFN -induced genes, also had the lowest complement gene expression levels. Furthermore, data from cultured human cells showed that IFN upregulates complement expression in macrophages, fibroblasts, and muscle cells. Taken together, our results suggest that in myositis muscle, IFN coordinates the local overexpression of complement genes that occurs in several cell types.
Project description:Myositis is characterised by muscle inflammation and weakness. Although generally thought to be driven by a systemic autoimmune response, increasing evidence suggests that intrinsic changes in the muscle might also contribute to the pathogenesis. Long non-coding RNAs (lncRNAs) are a family of novel genes that regulate gene transcription and translation. To determine the potential role of lncRNAs, we employed next generation sequencing to examine the transcriptome in muscle biopsies obtained from two histologically distinct patient populations, inclusion body myositis (IBM) and anti-Jo-1-associated myositis (Jo-1).
Project description:The relative contribution of innate and adaptive immunity to idiopathic inflammatory myopathy is poorly defined. We therefore sought to clarify these components of disease pathogenesis using our novel murine model of histidyl-tRNA synthetase (HRS)-induced myositis. Myositis was induced in WT and various congenic strains of C57BL/6 mice through intramuscular immunization with recombinant HRS. Histopathological, immunohistochemical, flow cytometric, and transcriptomic assessments were used to characterize muscle-infiltrating cell populations in these congenic strains. RAG1 KO mice developed markedly reduced muscle inflammation relative to WT mice, demonstrating a key requirement for T cells in driving HRS-induced myositis. Diminished cellular infiltration in CD4-Cre.MyD88fl/fl conditional knockout and OT-II TCR transgenic mice highlighted roles for innate and TCR-mediated/adaptive immune signaling in T cells. Transcriptionally-based pathway analyses showed that disruption of T cell signaling alters the function of macrophages, fibroblasts, and other non-lymphoid cell populations. Overall, these findings demonstrate that HRS-induced myositis reflects complex cellular interactions requiring the activation of both innate and adaptive T cell-mediated signaling pathways.