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Sayers S, Wagner E. On the Pleiotropic Actions of Glucagon-like Peptide-1 in Its Regulation of Homeostatic and Hedonic Feeding. Int J Mol Sci 2025; 26:3897. [PMID: 40332762 PMCID: PMC12027510 DOI: 10.3390/ijms26083897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2025] [Revised: 04/16/2025] [Accepted: 04/17/2025] [Indexed: 05/08/2025] Open
Abstract
We examined the neuroanatomical substrates and signaling mechanisms underlying the suppressive effect of GLP1 on homeostatic and hedonic feeding. Electrophysiological and behavioral studies were conducted in agouti-related peptide (AgRP)-cre and tyrosine hydroxylase (TH)-cre mice, and AgRP-cre/pituitary adenylyl cyclase-activating polypeptide (PACAP) type I receptor (PAC1R)fl/fl animals. GLP1 (30 pmol) delivered directly into the arcuate nucleus (ARC) decreased homeostatic feeding and diminished the rate of consumption. This anorexigenic effect was associated with an inhibitory outward current in orexigenic neuropeptide Y (NPY)/AgRP neurons. GLP1 injected into the ventral tegmental area reduced binge feeding, coupled with decrements in the rate of consumption and the percent daily caloric consumption during the binge interval. These reductions were associated with a GLP1-induced outward current in mesolimbic (A10) dopamine neurons. GLP1 administered into the ventromedial nucleus (VMN) reduced homeostatic feeding that again was associated with a diminished rate of consumption and abrogated by the GLP1 receptor antagonist exendin 9-39 and in AgRP-cre/PAC1Rfl/fl mice. This suppressive effect was linked with a GLP-induced inward current in VMN PACAP neurons, and further supported by the fact that GLP1 neurons in the nucleus tractus solitarius project to the VMN. Conversely, intra-VMN GLP1 had modest effects on binge feeding behavior. Finally, apoptotic ablation of VMN PACAP neurons obliterated the anorexigenic effect of intra-VMN GLP1 on homeostatic feeding in PACAP-cre mice but not their wildtype counterparts. Collectively, these data demonstrate that GLP1 acts within the homeostatic and hedonic circuits to curb appetitive behavior by exciting PACAP neurons, and inhibiting NPY/AgRP and A10 dopamine neurons.
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Affiliation(s)
| | - Ed Wagner
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA;
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Garnica-Siqueira MC, Martins AB, Monteiro ÉCAM, Oliveira MHBD, Baratto CDR, Tsutsui FTK, Oliveira LLFD, Stopa LRDS, Souza CFD, Wunderlich ALM, Zaia DAM, Leite CM, Zaia CTBV, Uchoa ET. Estrogens impair hypophagia and hypothalamic cell activation induced by vasoactive intestinal peptide, but not by pituitary adenylate cyclase-activating polypeptide. Peptides 2025; 183:171325. [PMID: 39617208 DOI: 10.1016/j.peptides.2024.171325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 11/27/2024] [Accepted: 11/27/2024] [Indexed: 12/07/2024]
Abstract
The neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) act in arcuate (ARC) and paraventricular (PVN) hypothalamic nuclei, reducing food intake and changing plasma parameters. Estrogens (E) also regulate energy homeostasis, and loss of ovarian function leads to hyperphagia and body weight gain. This study aimed to evaluate the effects of estradiol (E) in a postmenopausal rat model, ovariectomy (OVX), on PAC1 and VPAC2 receptors in the PVN and ARC, as well as on food intake, plasma parameters, and PVN and ARC cell activation in response to intracerebroventricular microinjection of VIP and PACAP. For this, the rats underwent intracerebroventricular and OVX surgeries, being treated daily with subcutaneous injections of 0.2 mL of corn oil or 10 μg/0.2 mL of estradiol cypionate, comprising the OVX+O and OVX+E groups, respectively. OVX+E showed reduced VPAC2 mRNA expression in the PVN. PACAP reduced food intake in both groups, and VIP-induced hypophagia was not observed in OVX+E. VIP increased plasma glucose in both groups, and PACAP increased plasma glucose only in OVX+O. VIP decreased free fatty acids in OVX+E. Furthermore, PACAP increased ARC cell activation in both groups, and in the PVN only in OVX+O. Cell activation induced by VIP in ARC and PVN was blocked by estradiol. Therefore, estrogens disrupted the hypophagia induced by VIP, but not by PACAP, and these differences seem to be, at least in part, due to an impairment of the activation of the ARC-PVN pathway.
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Affiliation(s)
- Marcela Cristina Garnica-Siqueira
- Laboratório de Fisiologia, Hospital de Reabilitação de Anomalias Craniofaciais, Universidade de São Paulo, Bauru, SP, Brazil; Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Andressa Busetti Martins
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Érica Cristina Alves Munhoz Monteiro
- Programa de Iniciação Científica do Conselho Nacional de Desenvolvimento Científico e Tecnológico, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Maria Heloisa Bernardes de Oliveira
- Programa de Iniciação Científica do Conselho Nacional de Desenvolvimento Científico e Tecnológico, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Carolina Dos Reis Baratto
- Programa de Iniciação Científica do Conselho Nacional de Desenvolvimento Científico e Tecnológico, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | | | | | - Larissa Rugila Dos Santos Stopa
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil; Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Camila Franciele de Souza
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil; Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | | | - Dimas Augusto Morozin Zaia
- Laboratório de Química Prebiótica, Departamento de Química, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | | | - Cássia Thaïs Bussamra Vieira Zaia
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil; Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil; Laboratório de Fisiologia Neuroendócrina e Metabolismo, Departamento de Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil.
| | - Ernane Torres Uchoa
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil; Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil; Laboratório de Fisiologia Neuroendócrina e Metabolismo, Departamento de Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil.
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Kelly MJ, Wagner EJ. Canonical transient receptor potential channels and hypothalamic control of homeostatic functions. J Neuroendocrinol 2024; 36:e13392. [PMID: 38631680 PMCID: PMC11444909 DOI: 10.1111/jne.13392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/21/2024] [Accepted: 03/28/2024] [Indexed: 04/19/2024]
Abstract
Recent molecular biological and electrophysiological studies have identified multiple transient receptor potential (TRP) channels in hypothalamic neurons as critical modulators of homeostatic functions. In particular, the canonical transient receptor potential channels (TRPCs) are expressed in hypothalamic neurons that are vital for the control of fertility and energy homeostasis. Classical neurotransmitters such as serotonin and glutamate and peptide neurotransmitters such as kisspeptin, neurokinin B and pituitary adenylyl cyclase-activating polypeptide signal through their cognate G protein-coupled receptors to activate TPRC 4, 5 channels, which are essentially ligand-gated calcium channels. In addition to neurotransmitters, circulating hormones like insulin and leptin signal through insulin receptor (InsR) and leptin receptor (LRb), respectively, to activate TRPC 5 channels in hypothalamic arcuate nucleus pro-opiomelanocortin (POMC) and kisspeptin (arcuate Kiss1 [Kiss1ARH]) neurons to have profound physiological (excitatory) effects. Besides its overt depolarizing effects, TRPC channels conduct calcium ions into the cytoplasm, which has a plethora of downstream effects. Moreover, not only the expression of Trpc5 mRNA but also the coupling of receptors to TRPC 5 channel opening are regulated in different physiological states. In particular, the mRNA expression of Trpc5 is highly regulated in kisspeptin neurons by circulating estrogens, which ultimately dictates the firing pattern of kisspeptin neurons. In obesity states, InsRs are "uncoupled" from opening TRPC 5 channels in POMC neurons, rendering them less excitable. Therefore, in this review, we will focus on the critical role of TRPC 5 channels in regulating the excitability of Kiss1ARH and POMC neurons in different physiological and pathological states.
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Affiliation(s)
- Martin J. Kelly
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon, 97239, USA
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon, 97001, USA
| | - Edward J. Wagner
- Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Pomona, CA 91766, USA
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Sayers S, Le N, Wagner EJ. The role of pituitary adenylate cyclase-activating polypeptide neurons in the hypothalamic ventromedial nucleus and the cognate PAC1 receptor in the regulation of hedonic feeding. Front Nutr 2024; 11:1437526. [PMID: 39234295 PMCID: PMC11371718 DOI: 10.3389/fnut.2024.1437526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Accepted: 07/29/2024] [Indexed: 09/06/2024] Open
Abstract
Obesity is a health malady that affects mental, physical, and social health. Pathology includes chronic imbalance between energy intake and expenditure, likely facilitated by dysregulation of the mesolimbic dopamine (DA) pathway. We explored the role of pituitary adenylate cyclase-activating polypeptide (PACAP) neurons in the hypothalamic ventromedial nucleus (VMN) and the PACAP-selective (PAC1) receptor in regulating hedonic feeding. We hypothesized that VMN PACAP neurons would inhibit reward-encoding mesolimbic (A10) dopamine neurons via PAC1 receptor activation and thereby suppress impulsive consumption brought on by intermittent exposure to highly palatable food. Visualized whole-cell patch clamp recordings coupled with in vivo behavioral experiments were utilized in wildtype, PACAP-cre, TH-cre, and TH-cre/PAC1 receptor-floxed mice. We found that bath application of PACAP directly inhibited preidentified A10 dopamine neurons in the ventral tegmental area (VTA) from TH-cre mice. This inhibitory action was abrogated by the selective knockdown of the PAC1 receptor in A10 dopamine neurons. PACAP delivered directly into the VTA decreases binge feeding accompanied by reduced meal size and duration in TH-cre mice. These effects are negated by PAC1 receptor knockdown in A10 dopamine neurons. Additionally, apoptotic ablation of VMN PACAP neurons increased binge consumption in both lean and obese, male and female PACAP-cre mice relative to wildtype controls. These findings demonstrate that VMN PACAP neurons blunt impulsive, binge feeding behavior by activating PAC1 receptors to inhibit A10 dopamine neurons. As such, they impart impactful insight into potential treatment strategies for conditions such as obesity and food addiction.
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Affiliation(s)
- Sarah Sayers
- College of Osteopathic Medicine of the Pacific, Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Nikki Le
- College of Osteopathic Medicine of the Pacific, Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Edward J Wagner
- College of Osteopathic Medicine of the Pacific, Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, United States
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Strnadová V, Pačesová A, Charvát V, Šmotková Z, Železná B, Kuneš J, Maletínská L. Anorexigenic neuropeptides as anti-obesity and neuroprotective agents: exploring the neuroprotective effects of anorexigenic neuropeptides. Biosci Rep 2024; 44:BSR20231385. [PMID: 38577975 PMCID: PMC11043025 DOI: 10.1042/bsr20231385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/26/2024] [Accepted: 04/05/2024] [Indexed: 04/06/2024] Open
Abstract
Since 1975, the incidence of obesity has increased to epidemic proportions, and the number of patients with obesity has quadrupled. Obesity is a major risk factor for developing other serious diseases, such as type 2 diabetes mellitus, hypertension, and cardiovascular diseases. Recent epidemiologic studies have defined obesity as a risk factor for the development of neurodegenerative diseases, such as Alzheimer's disease (AD) and other types of dementia. Despite all these serious comorbidities associated with obesity, there is still a lack of effective antiobesity treatment. Promising candidates for the treatment of obesity are anorexigenic neuropeptides, which are peptides produced by neurons in brain areas implicated in food intake regulation, such as the hypothalamus or the brainstem. These peptides efficiently reduce food intake and body weight. Moreover, because of the proven interconnection between obesity and the risk of developing AD, the potential neuroprotective effects of these two agents in animal models of neurodegeneration have been examined. The objective of this review was to explore anorexigenic neuropeptides produced and acting within the brain, emphasizing their potential not only for the treatment of obesity but also for the treatment of neurodegenerative disorders.
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Affiliation(s)
- Veronika Strnadová
- Department of Biochemistry and Molecular Biology, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Andrea Pačesová
- Department of Biochemistry and Molecular Biology, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Vilém Charvát
- Department of Biochemistry and Molecular Biology, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Šmotková
- Department of Biochemistry and Molecular Biology, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Blanka Železná
- Department of Biochemistry and Molecular Biology, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Jaroslav Kuneš
- Department of Biochemistry and Molecular Biology, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
- Department of Biochemistry and Molecular Biology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Lenka Maletínská
- Department of Biochemistry and Molecular Biology, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
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