Signaling pathways perturbing muscle mass
- PMID: 20397318
- DOI: 10.1097/mco.0b013e32833862df
Signaling pathways perturbing muscle mass
Abstract
Purpose of review: To discuss the mechanisms of muscle loss during cachexia.
Recent findings: Cachexia can be defined as a wasting of lean body mass that cannot be reversed nutrionally, indicating a dysregulation in the pathways maintaining body composition. In skeletal muscle, during cachexia, there is an upregulation of protein degradation. A search for transcriptional markers of muscle atrophy led to the discovery of the E3 ubiquitin ligases MuRF1 and MAFbx (also called Atrogin-1). These genes are upregulated in multiple models of atrophy and cachexia. They target particular protein substrates for degradation via the ubiquitin/proteasome pathway. The insulin-like growth factor-1 can block the transcriptional upregulation of MuRF1 and MAFbx via the phosphatidylinositol-3 kinase/Akt/Foxo pathway. MuRF1's substrates include several components of the sarcomeric thick filament, including myosin heavy chain. Thus, by blocking MuRF1, insulin-like growth factor-1 prevents the breakdown of the thick filament, particularly myosin heavy chain, which is asymmetrically lost in settings of cortisol-linked skeletal muscle atrophy. Insulin-like growth factor-1/phosphatidylinositol-3 kinase/Akt signaling also dominantly inhibits the effects of myostatin, which is a member of the transforming growth factor-[beta] family of proteins. Deletion or inhibition of myostatin causes a significant increase in skeletal muscle size. Recently, myostatin has been shown to act both by inhibiting gene activation associated with differentiation, even when applied to postdifferentiated myotubes, and by blocking the phosphatidylinositol-3 kinase/Akt pathway.
Summary: These findings will help to define strategies to treat cachexia.
Similar articles
-
PI3 kinase regulation of skeletal muscle hypertrophy and atrophy.Curr Top Microbiol Immunol. 2010;346:267-78. doi: 10.1007/82_2010_78. Curr Top Microbiol Immunol. 2010. PMID: 20593312 Review.
-
The IGF-1/PI3K/Akt pathway prevents expression of muscle atrophy-induced ubiquitin ligases by inhibiting FOXO transcription factors.Mol Cell. 2004 May 7;14(3):395-403. doi: 10.1016/s1097-2765(04)00211-4. Mol Cell. 2004. PMID: 15125842
-
SIRT1 protein, by blocking the activities of transcription factors FoxO1 and FoxO3, inhibits muscle atrophy and promotes muscle growth.J Biol Chem. 2013 Oct 18;288(42):30515-30526. doi: 10.1074/jbc.M113.489716. Epub 2013 Sep 3. J Biol Chem. 2013. PMID: 24003218 Free PMC article.
-
Inhibition of FoxO transcriptional activity prevents muscle fiber atrophy during cachexia and induces hypertrophy.FASEB J. 2012 Mar;26(3):987-1000. doi: 10.1096/fj.11-189977. Epub 2011 Nov 18. FASEB J. 2012. PMID: 22102632 Free PMC article.
-
Molecular signaling pathways regulating muscle proteolysis during atrophy.Curr Opin Clin Nutr Metab Care. 2005 May;8(3):271-5. doi: 10.1097/01.mco.0000165005.01331.45. Curr Opin Clin Nutr Metab Care. 2005. PMID: 15809529 Review.
Cited by
-
Changes in liver gluconeogenesis during the development of Walker-256 tumour in rats.Int J Exp Pathol. 2013 Feb;94(1):47-55. doi: 10.1111/iep.12002. Int J Exp Pathol. 2013. PMID: 23317353 Free PMC article.
-
TWEAK and TRAF6 regulate skeletal muscle atrophy.Curr Opin Clin Nutr Metab Care. 2012 May;15(3):233-9. doi: 10.1097/MCO.0b013e328351c3fc. Curr Opin Clin Nutr Metab Care. 2012. PMID: 22366923 Free PMC article. Review.
-
The landscape of aging.Sci China Life Sci. 2022 Dec;65(12):2354-2454. doi: 10.1007/s11427-022-2161-3. Epub 2022 Sep 2. Sci China Life Sci. 2022. PMID: 36066811 Free PMC article. Review.
-
COPD elicits remodeling of the diaphragm and vastus lateralis muscles in humans.J Appl Physiol (1985). 2013 May;114(9):1235-45. doi: 10.1152/japplphysiol.01121.2012. Epub 2012 Dec 20. J Appl Physiol (1985). 2013. PMID: 23264538 Free PMC article. Review.
-
Nandrolone normalizes determinants of muscle mass and fiber type after spinal cord injury.J Neurotrauma. 2012 May 20;29(8):1663-75. doi: 10.1089/neu.2011.2203. Epub 2012 Apr 16. J Neurotrauma. 2012. PMID: 22208735 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Research Materials
Miscellaneous