title: The ghrelin O-acyltransferase-ghrelin system: a novel regulator of glucose metabolism.
abstract: OBJECTIVE
  Ghrelin, an orexigenic hormone secreted from the stomach, exists in the circulation in two isoforms: des-acyl and acyl ghrelin. Acylation by the enzyme ghrelin O-acyl-transferase (GOAT) enables ghrelin to activate the ghrelin receptor. This review discusses recent findings illustrating the role of acyl ghrelin, des-acyl ghrelin and GOAT in regulating glucose homeostasis.
  
  
  RESULTS
  Recent publications support a role of ghrelin in modulating glucose homeostasis. Novel cellular mechanisms have been proposed to explain these effects. Controversy on this topic continues to exist owing to inconsistent observations made in both rodents and humans. Many recent studies are uncovering a role of des-acyl ghrelin in glucose metabolism specifically in modulating insulin sensitivity and glucose uptake into adipocytes. A novel role of ghrelin acylation by the enzyme GOAT in regulating glucose metabolism during caloric deprivation has newly been discovered.
  
  
  CONCLUSIONS
  Ghrelin plays a role in regulating glucose homeostasis through the modulation of insulin secretion and insulin sensitivity. Acyl ghrelin and des-acyl ghrelin appear to have opposing glucoregulatory effects and regulation of acylation by the enzyme GOAT appears to play a role in mediating glucose metabolism. Modulation of GOAT or ghrelin signaling may be a clinically relevant strategy to treat metabolic diseases such as type II diabetes.
authors.affiliation: Department of Medicine, Metabolic Diseases Institute, University of Cincinnati, Cincinnati, Ohio, USA.
authors.forename: Kristy M
authors.initials: KM
authors.lastname: Heppner
authors.forename: Jenny
authors.initials: J
authors.lastname: Tong
authors.forename: Henriette
authors.initials: H
authors.lastname: Kirchner
authors.forename: Ralf
authors.initials: R
authors.lastname: Nass
authors.forename: Matthias H
authors.initials: MH
authors.lastname: Tschöp
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000628:therapy; D004734:Energy Metabolism / Q000235:genetics; D054439:Ghrelin / Q000378:metabolism / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D048788:Growth and Development / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D015398:Signal Transduction / Q000502:physiology
chemical_list: D054439:Ghrelin; D007328:Insulin; D000217:Acyltransferases; C542776:MBOAT4 protein, human; D005947:Glucose