Potential role for Id myogenic repressors in apoptosis and attenuation of hypertrophy in muscles of aged rats
| Autor: | Stephen E. Alway, Cheryl A. Smith, Gururaj Krishnamurthy, Hans Degens |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Male
Senescence Aging medicine.medical_specialty Physiology Apoptosis Biology MyoD Muscle hypertrophy Atrophy Bloeddrukregulatie weefseloxygenatie en inspanning Proto-Oncogene Proteins Internal medicine medicine Animals RNA Messenger Muscle Skeletal Myogenin MyoD Protein bcl-2-Associated X Protein Body Weight Hypertrophy Cell Biology medicine.disease Caspase 9 Rats Inbred F344 Muscle atrophy Rats Repressor Proteins Endocrinology Proto-Oncogene Proteins c-bcl-2 Caspases Sarcopenia Bloodpressure regulation tissue oxygenation and exercise Plantaris muscle medicine.symptom Biomarkers |
| Zdroj: | Scopus-Elsevier American Journal of Physiology : Cell Physiology, 283, 1, pp. C66-76 American Journal of Physiology : Cell Physiology, 283, C66-76 |
| ISSN: | 0363-6143 |
| Popis: | Item does not contain fulltext Aging attenuates the overload-induced increase in myogenic regulatory transcription factor (MRF) expression and the extent of muscle enlargement. To identify whether mRNA levels of repressors of the MRFs are greater in overloaded muscles from aged animals, overload was achieved in plantaris muscle of aged (33 mo; n = 14) and adult (9 mo; n = 17) rats. After 14 days, plantaris muscles in the overloaded limb were ~25% and 6% larger in adult and aged rats, respectively, compared with the contralateral limb. Hypertrophied muscles of adult rats had significantly greater levels of mRNA and protein levels for myogenin and MyoD compared with control muscles, but neither MRF increased with overload in muscles of aged rats. Muscles of aged rats had greater Id mRNA (150-700%) and protein repressor (200-6,000%) levels compared with adult rats. BAX and caspase 9 protein levels were 9,500% and 300% greater, respectively, in both control and hypertrophied muscles of aged rats compared with young adult rats. These data are consistent with the hypothesis that aging increases Id transcripts that activate apoptotic pathways involving BAX. This may contribute to sarcopenia by attenuating MRF protein levels in muscles of old animals. |
| Databáze: | OpenAIRE |
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