Points of integration between the intracellular energy sensor AMP-activated protein kinase (AMPK) activity and the somatotroph axis function.
AMP-activated protein kinase (AMPK), an enzyme functioning as a cellular sensor of low energy, stores and promotes adaptive changes in growth, differentiation, and metabolism. While AMPK is primarily thought of as a regulator of systemic metabolism, it has been clearly established that it also has a role in the regulation of cell growth and may be a therapeutic target for proliferative disorders. Growth hormone (GH) secretion from the anterior pituitary and GH-induced synthesis and release of insulin-like-growth-factor-1 (IGF-1) from the liver determine linear growth before puberty. Actually, GH and IGF-1 are potent growth factors affecting cell growth and differentiation in different tissues, and still have anabolic functions and serve as essential regulators of fuel metabolism in adulthood, as well. A variety of peripheral hormonal and metabolic signals regulate GH secretion either by acting directly on the anterior pituitary and/or modulating GH-releasing hormone or somatostatin release from the hypothalamus. Actually, intracellular transduction of endocrine and metabolic signals regulating somatotroph function is still debated. Based on the previously summarized contents, the aim of the present work has been to review currently available data suggesting a role of AMPK in the interplay between GH axis activity and metabolic functions.
Department of Biomedical Sciences and Biotechnologies, Unit of Pharmacology, University of Brescia, Viale Europa 11, 25123 Brescia, Italy. tulipano@med.unibs.it
Giovanni
G
Tulipano
Lara
L
Faggi
Valeria
V
Sibilia
Andrea
A
Giustina
D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D004734:Energy Metabolism / Q000187:drug effects; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000188:drug therapy / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D019382:Human Growth Hormone / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D058990:Molecular Targeted Therapy; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D015398:Signal Transduction / Q000187:drug effects; D052683:Somatotrophs / Q000378:metabolism*
D000970:Antineoplastic Agents; D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D055372:AMP-Activated Protein Kinases