A well documented case of I-cell disease is presented. Light- and electron-microscopic studies of muscle revealed marked accumulation of characteristic I-cell inclusions in satellite cells and only scattered autophagic vacuoles in muscle fibers. Correlation with previous tissue culture studies indicated an amelioration of structural abnormalities with differentiation from satellite cell to mature muscle fiber. Histochemically, the muscle demonstrated paucity of type I fibers without evidence of denervation thus suggesting a developmental disturbance in motor unit organization. Selective type I fiber dysfunction and reduced satellite cell regenerative capacity may be related factors in the neuromuscular disability of patients with I-cell disease.
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http://dx.doi.org/10.1016/0022-510x(84)90110-2 | DOI Listing |
BMC Pediatr
December 2024
Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China.
Background: Mucolipidosis (ML) II and III alpha/beta are lysosomal disorders caused by mutations in the GNPTAB gene which encodes the alpha and beta subunits of the heterohexameric enzyme, N-acetylglucosamine-1-phosphotransferase.
Method: To explore the clinical and molecular characteristics of the 20 ML II and III alpha/beta patients, clinical data was collected and GNPTAB gene was analyzed by nest PCR and direct Sanger-sequencing. The activity of several lysosomal enzymes was measured in the plasma.
Orphanet J Rare Dis
November 2024
Department of Endocrinology, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, Genetics, Metabolism, Beijing, 100045, China.
Ann Clin Transl Neurol
November 2024
Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, 350005, China.
Mol Genet Metab
November 2024
Greenwood Genetic Center, Greenwood, SC 29646, United States of America. Electronic address:
Defining the molecular consequences of lysosomal dysfunction in neuronal cell types remains an area of investigation that is needed to understand many underappreciated phenotypes associated with lysosomal disorders. Here we characterize GNPTAB-knockout DAOY medulloblastoma cells using different genetic and proteomic approaches, with a focus on how altered gene expression and cell surface abundance of glycoproteins may explain emerging neurological issues in individuals with GNPTAB-related disorders, including mucolipidosis II (ML II) and mucolipidosis IIIα/β (ML IIIα/β). The two knockout clones characterized demonstrated all the biochemical hallmarks of this disease, including loss of intracellular glycosidase activity due to impaired mannose 6-phosphate-dependent lysosomal sorting, lysosomal cholesterol accumulation, and increased markers of autophagic dysfunction.
View Article and Find Full Text PDFAm J Physiol Gastrointest Liver Physiol
December 2024
Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.
Functional loss of the motor protein myosin Vb (MYO5B) induces various defects in intestinal epithelial function and causes a congenital diarrheal disorder, namely, microvillus inclusion disease (MVID). Utilizing the MVID model mice (MYO5BΔIEC) and [MYO5B(G519R)], we previously reported that functional MYO5B loss disrupts progenitor cell differentiation and enterocyte maturation that result in villus blunting and deadly malabsorption symptoms. In this study, we determined that both absence and a point mutation of MYO5B impair lipid metabolism and alter mitochondrial structure, which may underlie the progenitor cell malfunction observed in the MVID intestine.
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