Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD, MIM 226670) is caused by plectin defects. We performed mutational analysis and immunohistochemistry using EBS-MD (n = 3 cases) and control skeletal muscle to determine pathogenesis. Mutational analysis revealed a novel homozygous plectin-exon32 rod domain mutation (R2465X). All plectin/HD1-121 antibodies stained the control skeletal muscle membrane. However, plectin antibodies stained the cytoplasm of type II control muscle fibers (as confirmed by ATPase staining), whereas HD1-121 stained the cytoplasm of type I fibers. EBS-MD samples lacked membrane (n = 3) but retained cytoplasmic HD1-121 (n = 1) and plectin staining in type II fibers (n = 3). Ultrastructurally, EBS-MD demonstrated widening and vacuolization adjacent to the membrane and disorganization of Z-lines (n = 2 of 3) compared to controls (n = 5). Control muscle immunogold labeling colocalized plectin and desmin to filamentous bridges between Z-lines and the membrane that were disrupted in EBS-MD muscle. We conclude that fiber-specific plectin expression is associated with the desmin-cytoskeleton, Z-lines, and crucially myocyte membrane linkage, analogous to hemidesmosomes in skin.
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http://dx.doi.org/10.1002/mus.20655 | DOI Listing |
J Biol Chem
December 2024
Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan; Cancer and Immunology Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan. Electronic address:
Life Sci Alliance
December 2024
Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
Mol Biol Cell
November 2024
Department of Medicine Renal-Electrolyte Division and George M. O'Brien Pittsburgh Center for Kidney Research, University of Pittsburgh School of Medicine, Pittsburgh, PA.
The keratin cytoskeleton and associated desmosomes contribute to the mechanical stability of epithelial tissues, but their organization in native bladder umbrella cells and their responses to bladder filling are poorly understood. Using whole rat bladders in conjunction with confocal microscopy, super-resolution image processing, three-dimensional image reconstruction, and platinum replica electron microscopy, we identified a cortical cytoskeleton network in umbrella cells that was organized as a dense tile-like mesh comprised of tesserae bordered by cortical actin filaments, filled with keratin filaments, and cross-linked by plectin. Below these tesserae, keratin formed a subapical meshwork and at the cell periphery a band of keratin was linked via plectin to the junction-associated actin ring.
View Article and Find Full Text PDFJ Pediatr Gastroenterol Nutr
May 2024
Pediatric Hepatology and Liver Transplantation Unit, National Reference Centre for Biliary Atresia and Genetic Cholestasis, FILFOIE, ERN RARE LIVER, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Paris-Saclay University, Le Kremlin-Bicêtre, France.
Cells
January 2024
CNR Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", Unit of Bologna, 40136 Bologna, Italy.
In muscle cells subjected to mechanical stimulation, LINC complex and cytoskeletal proteins are basic to preserve cellular architecture and maintain nuclei orientation and positioning. In this context, the role of lamin A/C remains mostly elusive. This study demonstrates that in human myoblasts subjected to mechanical stretching, lamin A/C recruits desmin and plectin to the nuclear periphery, allowing a proper spatial orientation of the nuclei.
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