Cytoskeletal Abnormalities in Chondrocytes with EXT1 and EXT2 Mutations
| Autor: | Daniel D. Carson, Jacqueline T. Hecht, Dina Montufar-Solis, Mark B. Snuggs, Allison Scott, Tiffany Sanford, P. Jackie Duke, Deborah Hogue, William G. Cole, Mark A. Bernard, W. Barry Van Winkle |
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| Rok vydání: | 2010 |
| Předmět: |
Pathology
medicine.medical_specialty Tumor suppressor gene Macromolecular Substances Endocrinology Diabetes and Metabolism Hereditary multiple exostoses Blotting Western DNA Mutational Analysis Biology N-Acetylglucosaminyltransferases medicine.disease_cause Chondrocyte Germline mutation medicine Humans Protein Isoforms Vimentin Actinin Orthopedics and Sports Medicine Child Exostoses Cytoskeleton Exostosis Mutation Microscopy Confocal Cartilage Proteins medicine.disease Actins Cell biology medicine.anatomical_structure Microscopy Fluorescence Exostoses Multiple Hereditary |
| Zdroj: | Journal of Bone and Mineral Research. 15:442-450 |
| ISSN: | 0884-0431 |
| DOI: | 10.1359/jbmr.2000.15.3.442 |
| Popis: | The EXT genes are a group of putative tumor suppressor genes that previously have been shown to participate in the development of hereditary multiple exostoses (HME), HME-associated and isolated chondrosarcomas. Two HME disease genes, EXT1 and EXT2, have been identified and are expressed ubiquitously. However, the only known effect of mutations in the EXT genes is on chondrocyte function as evidenced by aberrant proliferation of chondrocytes leading to formation of bony, cartilage-capped projections (exostoses). In this study, we have characterized exostosis chondrocytes from three patients with HME (one with EXT1 and two with EXT2 germline mutations) and from one individual with a non-HME, isolated exostosis. At the light microscopic level, exostosis chondrocytes have a stellate appearance with elongated inclusions in the cytoplasm. Confocal and immunofluorescence of in vitro and in vivo chondrocytes showed that these massive accumulations are composed of actin bundled by 1.5-microm repeat cross-bridges of alpha-actinin. Western blot analysis shows that exostosis chondrocytes from two out of three patients aberrantly produce high levels of muscle-specific alpha-actin, whereas beta-actin levels are similar to normal chondrocytes. These findings suggest that mutations in the EXT genes cause abnormal processing of cytoskeleton proteins in chondrocytes. |
| Databáze: | OpenAIRE |
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