Aging increases the susceptibility of skeletal muscle derived satellite cells to apoptosis
| Autor: | Melanie G. Urbanchek, Paul S. Cederna, Sameer S. Jejurikar, William M. Kuzon, Cynthia L. Marcelo, Erika Henkelman |
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| Rok vydání: | 2006 |
| Předmět: |
Aging
Satellite Cells Skeletal Muscle Blotting Western Cell Apoptosis DNA Fragmentation Biochemistry Endocrinology Rats Inbred BN In Situ Nick-End Labeling Genetics medicine Animals Molecular Biology Cells Cultured Caspase Nucleic Acid Synthesis Inhibitors Microscopy Confocal TUNEL assay biology Tumor Necrosis Factor-alpha Skeletal muscle Cell Biology biology.organism_classification Rats Cell biology medicine.anatomical_structure Proto-Oncogene Proteins c-bcl-2 Caspases Immunology Dactinomycin biology.protein Female Tumor necrosis factor alpha Satellite (biology) Stem cell |
| Zdroj: | Experimental Gerontology. 41:828-836 |
| ISSN: | 0531-5565 |
| DOI: | 10.1016/j.exger.2006.06.053 |
| Popis: | The mechanisms causing the impaired regenerative response to injury observed in skeletal muscle of old animals are unknown. Satellite cells, stem cell descendants within adult skeletal muscle, are the primary source of regenerating muscle fibers. Apoptosis may be a mechanism responsible for the depletion of satellite cells in old animals. This work tested the hypothesis that aging increases the susceptibility of satellite cells to apoptosis. Satellite cells were cultured from the extensor digitorum longus muscles of young (3-month-old), adult (9-month-old), and old (31-month-old) Brown Norway rats. Satellite cells were treated for 24 h with the pro-apoptotic agents TNF-α (20 ng/mL) and Actinomycin D (250 ng/mL). Immunostaining for activated caspases and terminal deoxynucleotydil transferase-mediated dutp nick-end labeling (TUNEL) was performed to identify apoptotic satellite cells. Quantity of the anti-apoptotic protein bcl-2 was determined by Western blot analysis. Satellite cells from old animals demonstrated significantly higher percentages of cells with activated caspases and TUNEL-positive cells, and significantly lower amounts of bcl-2 compared to young and adult animals. These data support the hypothesis that aging increases satellite cell susceptibility to apoptosis. In old muscle, apoptosis may play a causative role in the depletion of satellite cells, impairing the regenerative response to injury. |
| Databáze: | OpenAIRE |
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