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Chronic stress inhibits growth and induces proteolytic mechanisms through two different nonoverlapping pathways in the skeletal muscle of a teleost fish.
- Source :
-
American journal of physiology. Regulatory, integrative and comparative physiology [Am J Physiol Regul Integr Comp Physiol] 2018 Jan 01; Vol. 314 (1), pp. R102-R113. Date of Electronic Publication: 2017 Oct 04. - Publication Year :
- 2018
-
Abstract
- Chronic stress detrimentally affects animal health and homeostasis, with somatic growth, and thus skeletal muscle, being particularly affected. A detailed understanding of the underlying endocrine and molecular mechanisms of how chronic stress affects skeletal muscle growth remains lacking. To address this issue, the present study assessed primary (plasma cortisol), secondary (key components of the GH/IGF system, muscular proteolytic pathways, and apoptosis), and tertiary (growth performance) stress responses in fine flounder ( Paralichthys adspersus) exposed to crowding chronic stress. Levels of plasma cortisol, glucocorticoid receptor 2 ( gr2), and its target genes ( klf15 and redd1) mRNA increased significantly only at 4 wk of crowding ( P < 0.05). The components of the GH/IGF system, including ligands, receptors, and their signaling pathways, were significantly downregulated at 7 wk of crowding ( P < 0.05). Interestingly, chronic stress upregulated the ubiquitin-proteasome pathway and the intrinsic apoptosis pathways at 4wk ( P < 0.01), whereas autophagy was only significantly activated at 7 wk ( P < 0.05), and meanwhile the ubiquitin-proteasome and the apoptosis pathways returned to control levels. Overall growth was inhibited in fish in the 7-wk chronic stress trial ( P < 0.05). In conclusion, chronic stress directly affects muscle growth and downregulates the GH/IGF system, an action through which muscular catabolic mechanisms are promoted by two different and nonoverlapping proteolytic pathways. These findings provide new information on molecular mechanisms involved in the negative effects that chronic stress has on muscle anabolic/catabolic signaling balance.
- Subjects :
- Age Factors
Animals
Apoptosis
Apoptosis Regulatory Proteins genetics
Apoptosis Regulatory Proteins metabolism
Autophagy
Autophagy-Related Proteins genetics
Autophagy-Related Proteins metabolism
Chronic Disease
Crowding
Disease Models, Animal
Fish Proteins genetics
Flounder blood
Flounder genetics
Flounder growth & development
Gene Expression Regulation
Hydrocortisone blood
Kruppel-Like Transcription Factors genetics
Kruppel-Like Transcription Factors metabolism
Proteasome Endopeptidase Complex genetics
Proteasome Endopeptidase Complex metabolism
Proteolysis
Receptors, Glucocorticoid genetics
Receptors, Glucocorticoid metabolism
Signal Transduction
Stress, Psychological genetics
Stress, Psychological physiopathology
Fish Proteins metabolism
Flounder metabolism
Muscle, Skeletal metabolism
Stress, Psychological metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1522-1490
- Volume :
- 314
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Regulatory, integrative and comparative physiology
- Publication Type :
- Academic Journal
- Accession number :
- 28978511
- Full Text :
- https://doi.org/10.1152/ajpregu.00009.2017