Skeletal muscle metabolic dysfunction and atrophy are prominent features of cachexia, a complex and devastating syndrome characterized by loss of body weight, loss of skeletal muscle and fat mass, and skeletal muscle weakness. Cachexia occurs as a consequence of a broad range of diseases, including uncontrolled hyperglycemia (i.e. diabetes), cancer, chronic lung, heart and kidney diseases, and AIDS;and in these disease states skeletal muscle wasting significantly contributes to disease mortality via a decrease in mobility and an impaired ability to respirate. Skeletal muscle wasting also occurs in healthy individuals as a normal response to aging, or in response to prolonged bouts of inactivity. Given this wide range of affected patients, and the consequences if muscle wasting is not reversed, determination of the cellular and molecular factors underlying the regulation of skeletal muscle mass is a critical undertaking that could lead to the development of pharmaceutical treatments for muscle wasting disorders. In muscle wasting disorders, dysregulation ofthe balance between protein synthesis and protein degradation shifts towards decreased protein synthesis, and this occurs via a decrease in the activation of the mammalian target of rapamycin (mTOR) signaling cascade. Despite the critical role that mTOR plays in regulating muscle mass, the upstream signaling pathways that regulate mTOR are still largely unknown. In this proposal, we present intriguing new data suggesting that the Ca2+-sensitive, serine/threonine kinase, Ca2+/calmodulin-dependent protein kinase kinase alpha (CaMKKalpha) is a novel regulator of skeletal muscle mass and mTOR signaling. Thus, in this application, we propose to investigate the role of CaMKKalpha in the regulation of growth, protein synthesis and mTOR signaling in skeletal muscle.

Public Health Relevance

Impaired metabolic dysfunction and loss of muscle mass are prominent features of many devastating diseases, including diabetes and cancer;and can also occur in healthy people in response to inactivity and aging. Determination of the cellular and molecular factors underlying the regulation of muscle mass could lead to the development of pharmaceutical treatments for muscle wasting disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Transition Award (R00)
Project #
5R00AR056298-04
Application #
8230213
Study Section
Special Emphasis Panel (NSS)
Program Officer
Boyce, Amanda T
Project Start
2011-02-01
Project End
2014-01-31
Budget Start
2012-02-01
Budget End
2013-01-31
Support Year
4
Fiscal Year
2012
Total Cost
$249,000
Indirect Cost
$75,481
Name
East Carolina University
Department
Miscellaneous
Type
Other Domestic Higher Education
DUNS #
607579018
City
Greenville
State
NC
Country
United States
Zip Code
27858
Ferey, Jeremie L A; Brault, Jeffrey J; Smith, Cheryl A S et al. (2014) Constitutive activation of CaMKK? signaling is sufficient but not necessary for mTORC1 activation and growth in mouse skeletal muscle. Am J Physiol Endocrinol Metab 307:E686-94
Hinkley, J Matthew; Ferey, Jeremie L; Brault, Jeffrey J et al. (2014) Constitutively active CaMKK* stimulates skeletal muscle glucose uptake in insulin-resistant mice in vivo. Diabetes 63:142-51