Central Control of Feeding Behavior by the Secretin, PACAP, and Glucagon Family of Peptides

Abstract

Constituting a group of structurally related brain-gut peptides, secretin (SCT), pituitary adenylate cyclase-activating peptide (PACAP), and glucagon (GCG) family of peptide hormones exert their functions via interactions with the class B1 G protein-coupled receptors. In recent years, the roles of these peptides in neuroendocrine control of feeding behavior have been a specific area of research focus for development of potential therapeutic drug targets to combat obesity and metabolic disorders. As a result, some members in the family and their analogs have already been utilized as therapeutic agents in clinical application. This review aims to provide an overview of the current understanding on the important role of SCT, PACAP, and GCG family of peptides in central control of feeding behavior.

Fresh-blood-free diet for rearing malaria mosquito vectors

“…Human ligands for GPCRs of several receptor families were selected and included peptides that activate Class A GPCRs (a.k.a Rhodopsin family GPCRs): oxytocin, galanin (GAL), kisspeptin, neuropeptide Y (NPY) that are basic determinants of reproductive functions 18 , luteinizing hormone releasing hormone (LHRH), which stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and triggers ovulation in females 19 and melatonin (MT) which regulates circadian rhythms of feeding 20 and peaks in the blood at dawn (when mosquitoes are more actively searching a blood meal); Ligands of Class B GPCRs (a.k.a. Secretin-GPCRs) glucagon-like peptide 1 (GLP1), glucagon-like peptide 2 (GLP2) and vasoactive intestinal peptide (VIP) that regulate feeding behaviour 21 , gut motility 22–24 , glucose and insulin metabolism 25,26 and parathyroid hormone (PTH), calcitonin (CT) and corticotrophin releasing hormone (CRH) which regulate ion metabolism and the stress response in humans and other vertebrates and also indirectly affects feeding behaviour 27–31 ; and of Class C GPCRs (a.k.a Glutamate GPCRs) the Glutamate and ɣ-aminobutyric acid (or GABA) which are two important neurotransmitters that stimulate feeding 32 . Two fish peptides (CT and LHRH) were also tested as they are potent activators of the human peptide receptors and have similar functions to their human orthologues 33,34 .…”

Review on PACAP-Induced Transcriptomic and Proteomic Changes in Neuronal Development and Repair

“…PACAP occurs at highest concentrations in the nervous system, where it functions as a neuromodulatory and neurotransmitter peptide. In the nervous system, PACAP acts, amongst others, on hypothalamic hormone release and hypothalamo-hypophyseal hormonal regulatory pathways [ 3 , 4 ], on central thermoregulatory and feeding routes [ 5 , 6 , 7 , 8 ], on neurogenesis [ 9 ] and on cognitive performance [ 10 , 11 , 12 ]. Of special importance is the action of PACAP on neuronal proliferation, differentiation and migration, whereby the peptide has significant effects in the development of the nervous system [ 13 , 14 ].…”

PACAP deficiency as a model of aging

“…The expression of PACAP and the activation of PAC1/PACAP signaling also depend on a variety of factors, including developmental stage (Basille et al 2000), balance between signaling pathways (Fukuchi et al 2016), environmental factors (Horvath et al 2015), physiological conditions (Kiss et al 2007;Nemeth et al 2006;Rudecki and Gray 2016), daily rhythm (Jozsa et al 2001;Somogyvari-Vigh et al 2002), and the presence of harmful stimuli (Giunta et al 2012;Lam et al 2012;Pettersson et al 2014;Somogyvari-Vigh et al 2002;Szakaly et al 2010) and pathological conditions (Ergang et al 2015;Feher et al 2018;Han et al 2014aHan et al , 2014bHelyes et al 2015;Sarszegi et al 2018). PACAP's actions are very diverse, among others, it plays important roles during the development of the nervous system and several peripheral organs (Fulop et al 2018a;Watanabe et al 2016), influences anxiety, stress coping and addictionrelated behaviors (Iemolo et al 2016;King et al 2017;Kormos et al 2016;Mai et al 2018;Miles et al 2018), cognitive functions (Han et al 2014a(Han et al , 2014b, feeding (Sekar et al 2017), thermoregulation (Barrett et al 2017;Garami et al 2016), endocrine functions (Egri et al 2016;Koves 2016), gastrointestinal secretion and motility (Padua et al 2016;Reglodi et al 2018b), urinary functions…”