Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Limb girdle muscular dystrophy type 2I (LGMD2I) is due to mutations in the fukutin-related protein gene (FKRP), encoding a putative glycosyltransferase involved in alpha-dystroglycan processing. To further characterize the molecular pathogenesis of LGMD2I, we conducted a histological, immunohistochemical, ultrastructural and molecular analysis of ten muscle biopsies from patients with molecularly diagnosed LGMD2I. Hypoglycosylation of alpha-dystroglycan was observed in all FKRP-mutated patients. Muscle histopathology was consistent with either severe muscular dystrophy or myopathy with a mild inflammatory response consisting of up-regulation of class I major histocompatibility complex in skeletal muscle fibers and small foci of mononuclear cells. At the ultrastructural level, muscle fibers showed focal thinning of basal lamina and swollen endoplasmic reticulum cisternae with membrane re-arrangement. The pathways of the unfolded protein response (UPR; glucose-regulated protein 78 and CHOP) were significantly activated in LGMD2I muscle tissue. Our data suggest that the UPR response is activated in LGMD2I muscle biopsies, and the observed histopathological and ultrastructural alterations may be related to sarcoplasmic structures involved in FKRP and alpha-dystroglycan metabolism and malfunctioning.
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PMID:Biochemical and ultrastructural evidence of endoplasmic reticulum stress in LGMD2I. 1795 92

Mutations in the caveolin-3 gene cause autosomal dominant limb-girdle muscular dystrophy 1C (LGMD1C). However, the precise molecular pathogenesis of caveolin-3-related muscular dystrophy remains uncertain. Here, we demonstrate the effect of gene dosage on the severity of the myopathic phenotype in P104L mutant caveolin-3 (mCav3(P104L)) transgenic mice, a model of LGMD1C. We analyzed the endoplasmic reticulum (ER) stress response in the transgenic mice and found upregulated transcription of the molecular chaperone, glucose-regulated protein (GRP78). Moreover, signaling downstream of GRP78 in the myofibers was activated toward apoptosis. However, terminal transferase dUTP nick end labeling assays detected a few apoptotic nuclei in transgenic mouse skeletal muscle, probably due to the transcriptional activation of Dad1, an anti-apoptotic factor in the ER. These findings suggest that the ER stress response caused by mCav3(P104L) plays a role in the pathogenesis of LGMD1C as a toxic gain of function effect.
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PMID:Endoplasmic reticulum stress response in P104L mutant caveolin-3 transgenic mice. 2161 Jan 59