Acute molecular response of mouse hindlimb muscles to chronic stimulation
| Autor: | Christin M. Sciulli, William A. LaFramboise, Robert W. Wiseman, David P. Ankrapp, K.L. Bombach, John M. Krill-Burger, Patricia Petrosko, Roop C. Jayaraman |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Contraction (grammar) Physiology Muscle Proteins Stimulation Muscle Cell Biology and Cell Motility Hindlimb Biology Time Kruppel-Like Factor 4 Mice Internal medicine medicine Animals Myocyte Muscle Skeletal Cells Cultured Staining and Labeling Myogenesis Gene Expression Profiling Cell Biology musculoskeletal system Sciatic Nerve Electrophysiology Endocrinology Gene Expression Regulation Sciatic nerve medicine.symptom Muscle Contraction Signal Transduction Muscle contraction |
| Zdroj: | American Journal of Physiology-Cell Physiology. 297:C556-C570 |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.00046.2009 |
| Popis: | Stimulation of the mouse hindlimb via the sciatic nerve was performed for a 4-h period to investigate acute muscle gene activation in a model of muscle phenotype conversion. Initial force production (1.6 ± 0.1 g/g body wt) declined 45% within 10 min and was maintained for the remainder of the experiment. Force returned to initial levels upon study completion. An immediate-early growth response was present in the extensor digitorum longus (EDL) muscle (FOS, JUN, activating transcription factor 3, and musculoaponeurotic fibrosarcoma oncogene) with a similar but attenuated pattern in the soleus muscle. Transcript profiles showed decreased fast fiber-specific mRNA (myosin heavy chains 2A and 2B, fast troponins T3and I, α-tropomyosin, muscle creatine kinase, and parvalbumin) and increased slow transcripts (myosin heavy chain-1β/slow, troponin C slow, and tropomyosin 3y) in the EDL versus soleus muscles. Histological analysis of the EDL revealed glycogen depletion without inflammatory cell infiltration in stimulated versus control muscles, whereas ultrastructural analysis showed no evidence of myofiber damage after stimulation. Multiple fiber type-specific transcription factors (tea domain family member 1, nuclear factor of activated T cells 1, peroxisome proliferator-activated receptor-γ coactivator-1α and -β, circadian locomotor output cycles kaput, and hypoxia-inducible factor-1α) increased in the EDL along with transcription factors characteristic of embryogenesis (Kruppel-like factor 4; SRY box containing 17; transcription factor 15; PBX/knotted 1 homeobox 1; and embryonic lethal, abnormal vision). No established in vivo satellite cell markers or genes activated in our parallel experiments of satellite cell proliferation in vitro (cyclins A2, B2, C, and E1and MyoD) were differentially increased in the stimulated muscles. These results indicated that the molecular onset of fast to slow phenotype conversion occurred in the EDL within 4 h of stimulation without injury or satellite cell recruitment. This conversion was associated with the expression of phenotype-specific transcription factors from resident fiber myonuclei, including the activation of nascent developmental transcriptional programs. |
| Databáze: | OpenAIRE |
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