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:Background Changes in protein turnover play an important role in dynamic physiological processes, including skeletal muscle regeneration, which occurs as an essential part of tissue repair after injury. The inability of muscle tissue to recapitulate this regenerative process can lead to pathology and clinical symptoms in various musculoskeletal diseases, including muscular dystrophies and pathological atrophy.
Methods Here, we employed a workflow that couples deuterated water (2H2O) administration with tandem mass spectrometry (MS) to systematically measure in-vivo protein turnover rates across the muscle proteome in 8-week-old male C57BL6/J mice. We compared the turnover kinetics of over 100 proteins in response to cardiotoxin (CTX) induced muscle damage and regeneration at unique sequential stages along the regeneration timeline. This analysis is compared to gene expression data from mRNA-sequencing (mRNA-seq) from the same tissue.
Results The data reveals quantitative protein flux signatures in response to necrotic damage, in addition to sequential differences in cell proliferation, energy metabolism, and contractile gene expression. Interestingly, the mRNA changes correlated poorly with changes in protein synthesis rates, consistent with post-transcriptional control mechanisms.	
Conclusions In summary, the experiments described here reveal the signatures and timing of protein flux changes during skeletal muscle regeneration, as well as the inability of mRNA expression measurements to reveal changes in directly measured protein turnover rates. The results of this work described here provide a better understanding of the muscle regeneration process and could help to identify potential biomarkers or therapeutic targets.
Project description:Background - Changes in protein turnover play an important role in dynamic physiological processes, including skeletal muscle regeneration, which occurs as an essential part of tissue repair after injury. The inability of muscle tissue to recapitulate this regenerative process can lead to pathology and clinical symptoms in various musculoskeletal diseases, including muscular dystrophies and pathological atrophy.
Methods - Here, we employed a workflow that couples deuterated water (2H2O) administration with tandem mass spectrometry (MS) to systematically measure in-vivo protein turnover rates across the muscle proteome in 8-week-old male C57BL6/J mice. We compared the turnover kinetics of over 100 proteins in response to cardiotoxin (CTX) induced muscle damage and regeneration at unique sequential stages along the regeneration timeline. This analysis is compared to gene expression data from mRNA-sequencing (mRNA-seq) from the same tissue.
Results - The data reveals quantitative protein flux signatures in response to necrotic damage, in addition to sequential differences in cell proliferation, energy metabolism, and contractile gene expression. Interestingly, the mRNA changes correlated poorly with changes in protein synthesis rates, consistent with post-transcriptional control mechanisms.	
Conclusions - In summary, the experiments described here reveal the signatures and timing of protein flux changes during skeletal muscle regeneration, as well as the inability of mRNA expression measurements to reveal changes in directly measured protein turnover rates. The results of this work described here provide a better understanding of the muscle regeneration process and could help to identify potential biomarkers or therapeutic targets.
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:To identify changes in skeletal muscle microRNA expression after exercise and associate the identified microRNAs with mRNA and protein expression to disease-specific pathways in polymyositis and dermatomyositis
Project description:We report the RNAseq gene expression levels of in the muscle biopsies of 39 subjects with adult dermatomyositis (DM) and 20 normal muscle specimens (NT)
Project description:MHC-I overexpression in muscle biopsies is a hallmark of inflammatory myopathies.However the mechanisms of MHC-I overexpression in each disease is not well understood. Microarray analysis from MHC-I-microdissected myofibers showed a differential expression signature in each inflammatory myopathy. Innate immunity and IFN-I pathways are upregulated vs healthy controls, specifically in dermatomyositis (DM). RNA from MHC-I-positive myofibers were obtained from muscle biopsies of 5 patients with dermatomyositis, 5 with polymyositis, 4 with inclusion body myositis and normal looking fibers from healthy controls.