title: Stress-related alterations of acyl and desacyl ghrelin circulating levels: mechanisms and functional implications.
abstract: Ghrelin is the only known peripherally produced and centrally acting peptide hormone that stimulates food intake and digestive functions. Ghrelin circulates as acylated and desacylated forms and recently the acylating enzyme, ghrelin-O-acyltransferase (GOAT) and the de-acylating enzyme, thioesterase 1/lysophospholipase 1 have been identified adding new layers of complexity to the regulation of ghrelin. Stress is known to alter gastrointestinal motility and food intake and was recently shown to modify circulating ghrelin and GOAT levels with differential responses related to the type of stressors including a reduction induced by physical stressors (abdominal surgery and immunological/endotoxin injection, exercise) and elevation by metabolic (cold exposure, acute fasting and caloric restriction) and psychological stressors. However, the pathways underlying the alterations of ghrelin under these various stress conditions are still largely to be defined and may relate to stress-associated autonomic changes. There is evidence that alterations of circulating ghrelin may contribute to the neuroendocrine and behavioral responses along with sustaining the energetic requirement needed upon repeated exposure to stressors. A better understanding of these mechanisms will allow targeting components of ghrelin signaling that may improve food intake and gastric motility alterations induced by stress.
authors.affiliation: CURE: Digestive Diseases Research Center, David Geffen School of Medicine, University of California Los Angeles and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, United States. andreas.stengel@charite.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Stengel
authors.forename: Lixin
authors.initials: L
authors.lastname: Wang
authors.forename: Yvette
authors.initials: Y
authors.lastname: Taché
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001341:Autonomic Nervous System / Q000378:metabolism; D004435:Eating / Q000502:physiology; D005215:Fasting / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D005769:Gastrointestinal Motility; D015870:Gene Expression; D054439:Ghrelin / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D054440:Receptors, Ghrelin / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013004:Somatostatin / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D013315:Stress, Psychological / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D013869:Thiolester Hydrolases / Q000235:genetics / Q000378:metabolism*
chemical_list: D054439:Ghrelin; D054440:Receptors, Ghrelin; C422650:ghrelin, des-n-octanoyl; D013004:Somatostatin; D000217:Acyltransferases; C542776:MBOAT4 protein, human; D058570:TOR Serine-Threonine Kinases; C402226:LYPLA1 protein, human; D013869:Thiolester Hydrolases