Maintaining skeletal muscle mass: lessons learned from hibernation

What is the topic of this review? This report describes identification and characterization of serum‐ and glucocorticoid‐regulated kinase 1 (SGK1) as a regulator of skeletal muscle mass during hibernation, as well as in physiological and pathophysiological conditions in non‐hibernating species. What advances does it highlight? This is first demonstration that SGK1 plays a crucial role in skeletal muscle homeostasis. Overexpression of SGK1 protects mice from immobilization and starvation‐induced muscle atrophy. Serum‐ and glucocorticoid‐regulated kinase 1 should be considered as a novel therapeutic target to combat loss of muscle mass in multiple conditions.

[1]  Deanna R. Brickley,et al.  Ubiquitin Modification of Serum and Glucocorticoid-induced Protein Kinase-1 (SGK-1)* , 2002, The Journal of Biological Chemistry.

[2]  G. Yancopoulos,et al.  Akt/mTOR pathway is a crucial regulator of skeletal muscle hypertrophy and can prevent muscle atrophy in vivo , 2001, Nature Cell Biology.

[3]  F. Artunc,et al.  Serum- and Glucocorticoid-Inducible Kinase 1 Mediates Salt Sensitivity of Glucose Tolerance , 2006, Diabetes.

[4]  F. Lang,et al.  Cloning and characterization of a putative human serine/threonine protein kinase transcriptionally modified during anisotonic and isotonic alterations of cell volume. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[5]  A. Goldberg,et al.  FoxO3 coordinately activates protein degradation by the autophagic/lysosomal and proteasomal pathways in atrophying muscle cells. , 2007, Cell metabolism.

[6]  G. Yancopoulos,et al.  Conditional Activation of Akt in Adult Skeletal Muscle Induces Rapid Hypertrophy , 2004, Molecular and Cellular Biology.

[7]  C. Stournaras,et al.  Serum and glucocorticoid inducible kinase, metabolic syndrome, inflammation, and tumor growth , 2013, Hormones.

[8]  C. Stournaras,et al.  Colorectal carcinoma cells--regulation of survival and growth by SGK1. , 2010, The international journal of biochemistry & cell biology.

[9]  Antonio Musarò,et al.  Localized Igf-1 transgene expression sustains hypertrophy and regeneration in senescent skeletal muscle , 2001, Nature Genetics.

[10]  N. Maraldi,et al.  Autophagy is defective in collagen VI muscular dystrophies, and its reactivation rescues myofiber degeneration , 2010, Nature Medicine.

[11]  B. Hemmings,et al.  Serum and Glucocorticoid-Responsive Kinase-1 Regulates Cardiomyocyte Survival and Hypertrophic Response , 2005, Circulation.

[12]  Brian A. Hemmings,et al.  Protein Kinase SGK Mediates Survival Signals by Phosphorylating the Forkhead Transcription Factor FKHRL1 (FOXO3a) , 2001, Molecular and Cellular Biology.

[13]  C. Stournaras,et al.  Relative resistance of SGK1 knockout mice against chemical carcinogenesis , 2009, IUBMB life.

[14]  A. Goldberg,et al.  FoxO3 controls autophagy in skeletal muscle in vivo. , 2007, Cell metabolism.

[15]  D. Alessi,et al.  mTOR complex 2 (mTORC2) controls hydrophobic motif phosphorylation and activation of serum- and glucocorticoid-induced protein kinase 1 (SGK1). , 2008, The Biochemical journal.

[16]  L. Leinwand,et al.  Activation of serum/glucocorticoid-induced kinase 1 (SGK1) is important to maintain skeletal muscle homeostasis and prevent atrophy , 2012, EMBO molecular medicine.

[17]  P. Cohen,et al.  Activation of serum- and glucocorticoid-regulated protein kinase by agonists that activate phosphatidylinositide 3-kinase is mediated by 3-phosphoinositide-dependent protein kinase-1 (PDK1) and PDK2. , 1999, The Biochemical journal.

[18]  A. C. Maiyar,et al.  Characterization of sgk, a novel member of the serine/threonine protein kinase gene family which is transcriptionally induced by glucocorticoids and serum , 1993, Molecular and cellular biology.

[19]  A. Náray-Fejes-Tóth,et al.  Serum- and glucocorticoid-inducible kinase 1 (SGK1) regulates adipocyte differentiation via forkhead box O1. , 2010, Molecular endocrinology.

[20]  K. Klingel,et al.  Impaired renal Na(+) retention in the sgk1-knockout mouse. , 2002, The Journal of clinical investigation.

[21]  Marcus D. Goncalves,et al.  Akt Deficiency Attenuates Muscle Size and Function but Not the Response to ActRIIB Inhibition , 2010, PloS one.