TY - JOUR

T1 - The role of ghrelin in weight-regulation disorders

T2 - implications in clinical practice

AU - Solomou, Solomis

AU - Korbonits, Márta

PY - 2015/1/3

Y1 - 2015/1/3

N2 - Ghrelin, an orexigenic protein with a unique lipid chain modification, is considered to be an important gut-brain signal for appetite control and energy balance. The ghrelin receptor, growth-hormone secretagogue receptor type 1a, is able to bind acylated ghrelin. The first recognised effect of ghrelin was the induction of growth hormone release from the somatotroph cells of the anterior pituitary. Moreover, by acting on vagal afferents or centrally, ghrelin can activate hypothalamic arcuate neurons that secrete the orexigenic peptides neuropeptide Y and agouti-related peptide, and inhibit the anorexigenic neurons secreting pro-opiomelanocortin and α-melanocyte-stimulating hormone. The orexigenic signalling pathway of ghrelin involves adenosine monophosphate-activated protein kinase. It has been proposed that ghrelin can also increase dopaminergic transmission from the ventral tegmental area to the nucleus accumbens, leading to augmentation of afferent reward signals. Present evidence suggests that ghrelin plays an important role in obesity, eating disorders, and cachexia, as well as in regulating appetite and energy balance in healthy individuals. In pathological states, ghrelin can be lower than normal as is seen in obese individuals, or can be higher than normal as has been reported for Prader-Willi syndrome, anorexia nervosa, bulimia nervosa, and certain types of cachexia. In the future, the application of compounds targeting the ghrelin pathway could involve the use of pharmacotherapies of ghrelin agonists, antagonists or inverse agonists, neutralisation of ghrelin by vaccines and spiegelmers, desacyl ghrelin analogues, as well as inhibitors of the GOAT enzyme which attaches the lipid modification to desacyl ghrelin to synthetise ghrelin.

AB - Ghrelin, an orexigenic protein with a unique lipid chain modification, is considered to be an important gut-brain signal for appetite control and energy balance. The ghrelin receptor, growth-hormone secretagogue receptor type 1a, is able to bind acylated ghrelin. The first recognised effect of ghrelin was the induction of growth hormone release from the somatotroph cells of the anterior pituitary. Moreover, by acting on vagal afferents or centrally, ghrelin can activate hypothalamic arcuate neurons that secrete the orexigenic peptides neuropeptide Y and agouti-related peptide, and inhibit the anorexigenic neurons secreting pro-opiomelanocortin and α-melanocyte-stimulating hormone. The orexigenic signalling pathway of ghrelin involves adenosine monophosphate-activated protein kinase. It has been proposed that ghrelin can also increase dopaminergic transmission from the ventral tegmental area to the nucleus accumbens, leading to augmentation of afferent reward signals. Present evidence suggests that ghrelin plays an important role in obesity, eating disorders, and cachexia, as well as in regulating appetite and energy balance in healthy individuals. In pathological states, ghrelin can be lower than normal as is seen in obese individuals, or can be higher than normal as has been reported for Prader-Willi syndrome, anorexia nervosa, bulimia nervosa, and certain types of cachexia. In the future, the application of compounds targeting the ghrelin pathway could involve the use of pharmacotherapies of ghrelin agonists, antagonists or inverse agonists, neutralisation of ghrelin by vaccines and spiegelmers, desacyl ghrelin analogues, as well as inhibitors of the GOAT enzyme which attaches the lipid modification to desacyl ghrelin to synthetise ghrelin.

KW - Animals

KW - Body Weight/genetics

KW - Cachexia/genetics

KW - Energy Metabolism/physiology

KW - Feeding and Eating Disorders/genetics

KW - Ghrelin/chemistry

KW - Humans

KW - Nutrition Disorders/genetics

KW - Obesity/genetics

KW - Prader-Willi Syndrome/genetics

KW - Signal Transduction/genetics

KW - Structure-Activity Relationship

U2 - 10.14310/horm.2002.1551

DO - 10.14310/horm.2002.1551

M3 - Review article

C2 - 25555181

VL - 13

SP - 458

EP - 475

JO - Hormones (Athens, Greece)

JF - Hormones (Athens, Greece)

SN - 1109-3099

IS - 4

ER -