Transcriptional regulation of decreased protein synthesis during skeletal muscle unloading
| Autor: | T. E. Geoghegan, J. M. Steffen, G. Howard |
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| Rok vydání: | 1989 |
| Předmět: |
Male
medicine.medical_specialty Transcription Genetic Physiology Biology Atrophy Reference Values Transcription (biology) Physiology (medical) Internal medicine medicine Protein biosynthesis Transcriptional regulation Animals RNA Messenger Messenger RNA Muscles musculoskeletal neural and ocular physiology Nucleic Acid Hybridization RNA Skeletal muscle Rats Inbred Strains Decreased Protein Synthesis Blotting Northern musculoskeletal system medicine.disease Actins Rats medicine.anatomical_structure Endocrinology Gene Expression Regulation Genes Biochemistry tissues |
| Zdroj: | Journal of Applied Physiology. 66:1093-1098 |
| ISSN: | 1522-1601 8750-7587 |
| Popis: | Muscle atrophy resulting from disuse is associated with marked decrements in protein synthesis. The objective of the present investigation was to determine levels of total muscle RNA and the content and composition of the mRNA fraction as a qualitative assessment of the potential regulatory role of transcriptional alterations in unloaded skeletal muscles. Hindlimb muscle unloading was produced by whole-body suspension of rats for up to 7 days. The soleus, gastrocnemius, and extensor digitorum longus (EDL) were excised from 1-, 3-, and 7-day suspended and pair-fed controls, and RNA was extracted by homogenization in 5 M guanidinium thiocyanate. Total RNA and mRNA contents were lower in soleus and gastrocnemius after 7 days of suspension compared with pair-fed controls, but total RNA and mRNA concentrations (per g muscle and per microgram total RNA, respectively) were unaltered. alpha-Actin mRNA, assessed by dot blot hybridization, was significantly reduced in soleus after 1 (37%), 3 (28%), and 7 (59%) days of suspension and in gastrocnemius after 3 (44%) and 7 (41%) days. However, alpha-actin mRNA was unchanged in the EDL after suspension. Protein synthesis directed by RNA extracted from soleus and EDL indicated marked (30–400%) alterations in mRNAs coding for several small (15- to 25-kDa) proteins. The results of this study suggest that altered transcription and availability of specific mRNAs could contribute significantly to the regulation of protein synthesis during unloading of skeletal muscle. |
| Databáze: | OpenAIRE |
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