Myopathy
- Deterioration of muscle force and contractile characteristics are early pathological events in spinal and bulbar muscular atrophy mice
Summary: Research on the AR100 mouse model of spinal and bulbarmuscular atrophy shows that disease manifests first in skeletal muscle, before motor neuron degeneration, which only occurs in the late stage of disease.
- Loss of function of Colgalt1 disrupts collagen post-translational modification and causes musculoskeletal defects
Summary: The authors characterized a novel mouse mutant that has a defect in collagen glycosylation, which appears to affect muscle development. There is very little functional characterization of the affected gene, but this study provides analysis of its embryonic phenotype and the biochemistry of the null mutant, as well as the phenotype of null-mutant zebrafish.
- Transcriptional upregulation of Bag3, a chaperone-assisted selective autophagy factor, in animal models of KY-deficient hereditary myopathy
Summary: Increased transcriptional activation of the tension-mediated autophagy factor Bag3 is shown to be a consistent molecular hallmark of KY deficiency in animal models.
- Use of sodium 4-phenylbutyrate to define therapeutic parameters for reducing intracerebral hemorrhage and myopathy in Col4a1 mutant mice
Summary: COL4A1 mutations cause a multisystem disorder by impairing secretion of COL4A1/A2 heterotrimers. We define parameters for reducing stroke and myopathy in Col4a1 mutant mice by pharmacologically promoting heterotrimer secretion.
- SIL1, the endoplasmic-reticulum-localized BiP co-chaperone, plays a crucial role in maintaining skeletal muscle proteostasis and physiology
Editor's choice: This study provides molecular insights into the progressive myopathy and cellular compensatory responses attempted upon loss of SIL1, a component of the endoplasmic-reticulum-resident Hsp70 protein-folding machinery.
- p53-independent DUX4 pathology in cell and animal models of facioscapulohumeral muscular dystrophy
Summary: DUX4 is thought to mediate cytopathology through p53. Here, DUX4 is shown to kill primary myoblasts and promote pathological phenotypes in the iDUX4[2.7] mouse model on the p53-null background, calling into question this notion.
- Mouse myofibers lacking the SMYD1 methyltransferase are susceptible to atrophy, internalization of nuclei and myofibrillar disarray
Summary: Elimination of the lysine methyltransferase SMYD1 from mouse skeletal muscle caused myopathy with excessive internal nuclei, atrophy, myofibrillar disorganization and broad upregulation of muscle gene expression.