1
|
Rojo D, Hael CE, Soria A, de Souza FSJ, Low MJ, Franchini LF, Rubinstein M. A mammalian tripartite enhancer cluster controls hypothalamic Pomc expression, food intake, and body weight. Proc Natl Acad Sci U S A 2024; 121:e2322692121. [PMID: 38652744 DOI: 10.1073/pnas.2322692121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/12/2024] [Indexed: 04/25/2024] Open
Abstract
Food intake and energy balance are tightly regulated by a group of hypothalamic arcuate neurons expressing the proopiomelanocortin (POMC) gene. In mammals, arcuate-specific POMC expression is driven by two cis-acting transcriptional enhancers known as nPE1 and nPE2. Because mutant mice lacking these two enhancers still showed hypothalamic Pomc mRNA, we searched for additional elements contributing to arcuate Pomc expression. By combining molecular evolution with reporter gene expression in transgenic zebrafish and mice, here, we identified a mammalian arcuate-specific Pomc enhancer that we named nPE3, carrying several binding sites also present in nPE1 and nPE2 for transcription factors known to activate neuronal Pomc expression, such as ISL1, NKX2.1, and ERα. We found that nPE3 originated in the lineage leading to placental mammals and remained under purifying selection in all mammalian orders, although it was lost in Simiiformes (monkeys, apes, and humans) following a unique segmental deletion event. Interestingly, ablation of nPE3 from the mouse genome led to a drastic reduction (>70%) in hypothalamic Pomc mRNA during development and only moderate (<33%) in adult mice. Comparison between double (nPE1 and nPE2) and triple (nPE1, nPE2, and nPE3) enhancer mutants revealed the relative contribution of nPE3 to hypothalamic Pomc expression and its importance in the control of food intake and adiposity in male and female mice. Altogether, these results demonstrate that nPE3 integrates a tripartite cluster of partially redundant enhancers that originated upon a triple convergent evolutionary process in mammals and that is critical for hypothalamic Pomc expression and body weight homeostasis.
Collapse
Affiliation(s)
- Daniela Rojo
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires 1428, Argentina
| | - Clara E Hael
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires 1428, Argentina
| | - Agustina Soria
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires 1428, Argentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Flávio S J de Souza
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires 1428, Argentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105
| | - Lucía F Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires 1428, Argentina
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires 1428, Argentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105
| |
Collapse
|
2
|
Roth CL, McCormack SE. Acquired hypothalamic obesity: A clinical overview and update. Diabetes Obes Metab 2024; 26 Suppl 2:34-45. [PMID: 38450938 DOI: 10.1111/dom.15530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/13/2024] [Accepted: 02/15/2024] [Indexed: 03/08/2024]
Abstract
Hypothalamic obesity (HO) is a rare and complex disorder that confers substantial morbidity and excess mortality. HO is a unique subtype of obesity characterized by impairment in the key brain pathways that regulate energy intake and expenditure, autonomic nervous system function, and peripheral hormonal signalling. HO often occurs in the context of hypothalamic syndrome, a constellation of symptoms that follow from disruption of hypothalamic functions, for example, temperature regulation, sleep-wake circadian control, and energy balance. Genetic forms of HO, including the monogenic obesity syndromes, often impact central leptin-melanocortin pathways. Acquired forms of HO occur as a result of tumours impacting the hypothalamus, such as craniopharyngioma, surgery or radiation to treat those tumours, or other forms of hypothalamic damage, such as brain injury impacting the region. Risk for severe obesity following hypothalamic injury is increased with larger extent of hypothalamic damage or lesions that contain the medial and posterior hypothalamic nuclei that support melanocortin signalling pathways. Structural damage in these hypothalamic nuclei often leads to hyperphagia, central insulin and leptin resistance, decreased sympathetic activity, low energy expenditure, and increased energy storage in adipose tissue, the collective effect of which is rapid weight gain. Individuals with hyperphagia are perpetually hungry. They do not experience fullness at the end of a meal, nor do they feel satiated after meals, leading them to consume larger and more frequent meals. To date, most efforts to treat HO have been disappointing and met with limited, if any, long-term success. However, new treatments based on the distinct pathophysiology of disturbed energy homeostasis in acquired HO may hold promise for the future.
Collapse
Affiliation(s)
- Christian L Roth
- Centre for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, DC, USA
- Department of Paediatrics, University of Washington, School of Medicine, Seattle, Washington, DC, USA
| | - Shana E McCormack
- Neuroendocrine Centre, Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Paediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
3
|
Oya M, Miyasaka Y, Nakamura Y, Tanaka M, Suganami T, Mashimo T, Nakamura K. Age-related ciliopathy: Obesogenic shortening of melanocortin-4 receptor-bearing neuronal primary cilia. Cell Metab 2024:S1550-4131(24)00056-1. [PMID: 38452767 DOI: 10.1016/j.cmet.2024.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 01/16/2024] [Accepted: 02/15/2024] [Indexed: 03/09/2024]
Abstract
Obesity is often associated with aging. However, the mechanism of age-related obesity is unknown. The melanocortin-4 receptor (MC4R) mediates leptin-melanocortin anti-obesity signaling in the hypothalamus. Here, we discovered that MC4R-bearing primary cilia of hypothalamic neurons progressively shorten with age in rats, correlating with age-dependent metabolic decline and increased adiposity. This "age-related ciliopathy" is promoted by overnutrition-induced upregulation of leptin-melanocortin signaling and inhibited or reversed by dietary restriction or the knockdown of ciliogenesis-associated kinase 1 (CILK1). Forced shortening of MC4R-bearing cilia in hypothalamic neurons by genetic approaches impaired neuronal sensitivity to melanocortin and resulted in decreased brown fat thermogenesis and energy expenditure and increased appetite, finally developing obesity and leptin resistance. Therefore, despite its acute anti-obesity effect, chronic leptin-melanocortin signaling increases susceptibility to obesity by promoting the age-related shortening of MC4R-bearing cilia. This study provides a crucial mechanism for age-related obesity, which increases the risk of metabolic syndrome.
Collapse
Affiliation(s)
- Manami Oya
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Yoshiki Miyasaka
- Institute of Experimental Animal Sciences, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Yoshiko Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Miyako Tanaka
- Department of Molecular Medicine and Metabolism, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan; Department of Immunometabolism, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Institute of Nano-Life-Systems, Institutes of Innovation for Future Society, Nagoya University, Nagoya 464-8601, Japan
| | - Takayoshi Suganami
- Department of Molecular Medicine and Metabolism, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan; Department of Immunometabolism, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Institute of Nano-Life-Systems, Institutes of Innovation for Future Society, Nagoya University, Nagoya 464-8601, Japan; Center for One Medicine Innovative Translational Research (COMIT), Nagoya University, Nagoya 464-8601, Japan
| | - Tomoji Mashimo
- Institute of Experimental Animal Sciences, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan; Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Division of Genome Engineering, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Kazuhiro Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
| |
Collapse
|
4
|
Guijo B, Argente J, Martos-Moreno GÁ. The N221D variant in PCSK1 is highly prevalent in childhood obesity and can influence the metabolic profile. J Pediatr Endocrinol Metab 2023; 36:1140-1145. [PMID: 37877373 DOI: 10.1515/jpem-2023-0395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/09/2023] [Indexed: 10/26/2023]
Abstract
OBJECTIVES To study the prevalence and influence on metabolic profile of the prohormone-convertase-1 (PCSK1) N221D variant in childhood obesity, proven its role in the leptin-melanocortin signaling pathway as in proinsulin and other prohormone cleavage. METHODS Transversal study of 1066 children with obesity (mean age and BMI Z-score 10.38 ± 3.44 years and +4.38 ± 1.77, respectively), 51.4 % males, 54.4 % prepubertal, 71.5 % Caucasians and 20.8 % Latinos. Anthropometric and metabolic features were compared between patients carrying the N221D variant in PCSK1 and patients with no variants found after next generation sequencing analysis of 17 genes (CREBBP, CPE, HTR2C, KSR2, LEP, LEPR, MAGEL2, MC3R, MC4R, MRAP2, NCOA1, PCSK1, POMC, SH2B1, SIM1, TBX3 and TUB) involved in the leptin-melanocortin pathway. RESULTS No variants were found in 531 patients (49.8 %), while 68 patients carried the PCSK1 N221D variant (42 isolately, and 26 with at least one additional gene variant). Its prevalence was higher in Caucasians vs. Latinos (χ2 7.81; p<0.01). Patients carrying exclusively the PCSK1 N221D variant (n=42) showed lower insulinemia (p<0.05), HOMA index (p<0.05) and area under the curve for insulin in the oral glucose tolerance test (p<0.001) and higher WBISI (p<0.05) than patients with no variants, despite similar obesity severity, age, sex and ethnic distribution. CONCLUSIONS The N221D variant in PCSK1 is highly prevalent in childhood obesity, influenced by ethnicity. Indirect estimation of insulin resistance, based on insulinemia could be byassed in these patients and underestimate their type 2 diabetes mellitus risk.
Collapse
Affiliation(s)
- Blanca Guijo
- Departments of Pediatrics and Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
| | - Jesús Argente
- Departments of Pediatrics and Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Instituto de alimentación IMDEA, CEIUAM+CSIC, Madrid, Spain
| | - Gabriel Ángel Martos-Moreno
- Departments of Pediatrics and Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
5
|
Bora A, Fisette A. The obese brain: is it a matter of time? Trends Endocrinol Metab 2023; 34:691-693. [PMID: 37640666 DOI: 10.1016/j.tem.2023.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/31/2023]
Abstract
Understanding how obesity rewires the brain, triggers neuroinflammation and neurodegeneration relies on research using animal models. There is, however, a disconnect between the timeline of human obesity and typical preclinical protocols. We emphasize here the need to adopt models of chronic obesity to study the pathophysiology of human obesity.
Collapse
Affiliation(s)
- Ambica Bora
- Research Group in Cellular Signaling, Department of Medical Biology, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Alexandre Fisette
- Research Group in Cellular Signaling, Department of Medical Biology, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada.
| |
Collapse
|
6
|
Farooqi S. Obesity and thinness: insights from genetics. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220205. [PMID: 37661743 PMCID: PMC10475868 DOI: 10.1098/rstb.2022.0205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/09/2023] [Indexed: 09/05/2023] Open
Abstract
Genetic disruption of key molecular components of the hypothalamic leptin-melanocortin pathway causes severe obesity in mice and humans. Physiological studies in people who carry these mutations have shown that the adipose tissue-derived hormone leptin primarily acts to defend against starvation. A lack of leptin causes an intense drive to eat and increases the rewarding properties of food, demonstrating that human appetite has a strong biological basis. Genetic studies in clinical- and population-based cohorts of people with obesity or thinness continue to provide new insights into the physiological mechanisms involved in weight regulation and identify molecular targets for weight loss therapy. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.
Collapse
Affiliation(s)
- Sadaf Farooqi
- Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Box 289, Cambridge CB2 0QQ, UK
| |
Collapse
|
7
|
Gebrie A. The melanocortin receptor signaling system and its role in neuroprotection against neurodegeneration: Therapeutic insights. Ann N Y Acad Sci 2023; 1527:30-41. [PMID: 37526975 DOI: 10.1111/nyas.15048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
The melanocortin signaling system consists of the melanocortin peptides, their distinctive receptors, accessory proteins, and endogenous antagonists. Melanocortin peptides are small peptide hormones that have been studied in a variety of physiological and pathological conditions. There are five types of melanocortin receptors, and they are distributed within the central nervous system and in several tissues of the periphery. The G protein-coupled melanocortin receptors typically signal through adenylyl cyclase and other downstream signaling pathways. Depending on the ligand, surface expression of melanocortin receptor, receptor occupancy period, related proteins, the type of cell, and other parameters, the signaling pathways are complicated and pleiotropic. While it is known that all five melanocortin receptors are coupled to Gs, they can also occasionally couple to Gq or Gi. Both direct and indirect neuroprotection are induced by the melanocortin signaling system. Targeting several of the components of the melanocortin signaling system (ligands, receptors, accessory proteins, signaling effectors, and regulators) may provide therapeutic opportunities. Activation of the melanocortin system improves different functional traits in neurodegenerative diseases. There is a potential for additional melanocortin system interventions by interfering with dimerization or dissociation. This review aims to discuss the melanocortin receptor signaling system and its role in neuroprotection, as well as its therapeutic potential.
Collapse
Affiliation(s)
- Alemu Gebrie
- Department of Biomedical Sciences, School of Medicine, Debre Markos University, Debre Markos, Ethiopia
| |
Collapse
|
8
|
Mun Y, Kim W, Shin D. Melanocortin 1 Receptor (MC1R): Pharmacological and Therapeutic Aspects. Int J Mol Sci 2023; 24:12152. [PMID: 37569558 PMCID: PMC10418475 DOI: 10.3390/ijms241512152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 06/22/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023] Open
Abstract
Melanocortins play crucial roles in regulating the stress response, inflammation, and skin pigmentation. In this review, we focus on the melanocortin 1 receptor (MC1R), a G protein-coupled receptor primarily known for regulating skin pigmentation and exhibiting anti-inflammatory effects. First, we provide an overview of the structure, signaling pathways, and related diseases of MC1R. Next, we discuss the potential therapeutic use of synthetic peptides and small molecule modulators of MC1R, highlighting the development of various drugs that enhance stability through amino acid sequence modifications and small molecule drugs to overcome limitations associated with peptide characteristics. Notably, MC1R-targeted drugs have applications beyond skin pigmentation-related diseases, which predominantly affect MC1R in melanocytes. These drugs can also be useful in treating inflammatory diseases with MC1R expression present in various cells. Our review underscores the potential of MC1R-targeted drugs to treat a wide range of diseases and encourages further research in this area.
Collapse
Affiliation(s)
- Yoonwoo Mun
- College of Pharmacy, Gachon University, 191 Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Republic of Korea; (Y.M.); (W.K.)
| | - Woohyun Kim
- College of Pharmacy, Gachon University, 191 Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Republic of Korea; (Y.M.); (W.K.)
| | - Dongyun Shin
- College of Pharmacy, Gachon University, 191 Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Republic of Korea; (Y.M.); (W.K.)
- Gachon Pharmaceutical Research Institute, Gachon University, 191 Hambakmoe-ro, Yeonsu-gu, Incheon 21936, Republic of Korea
| |
Collapse
|
9
|
Gravina AG, Pellegrino R, Durante T, Palladino G, Imperio G, D'Amico G, Trotta MC, Dallio M, Romeo M, D'Amico M, Federico A. The Melanocortin System in Inflammatory Bowel Diseases: Insights into Its Mechanisms and Therapeutic Potentials. Cells 2023; 12:1889. [PMID: 37508552 PMCID: PMC10378568 DOI: 10.3390/cells12141889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 07/08/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
The melanocortin system is a complex set of molecular mediators and receptors involved in many physiological and homeostatic processes. These include the regulation of melanogenesis, steroidogenesis, neuromodulation and the modulation of inflammatory processes. In the latter context, the system has assumed importance in conditions of chronic digestive inflammation, such as inflammatory bowel diseases (IBD), in which numerous experiences have been accumulated in mouse models of colitis. Indeed, information on how such a system can counteract colitis inflammation and intervene in the complex cytokine imbalance in the intestinal microenvironment affected by chronic inflammatory damage has emerged. This review summarises the evidence acquired so far and highlights that molecules interfering with the melanocortin system could represent new drugs for treating IBD.
Collapse
Affiliation(s)
- Antonietta Gerarda Gravina
- Hepatogastroenterology Unit, Department of Precision Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Raffaele Pellegrino
- Hepatogastroenterology Unit, Department of Precision Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Tommaso Durante
- Mental Health Department, S. Pio Hospital, Via dell'Angelo, 82100 Benevento, Italy
| | - Giovanna Palladino
- Hepatogastroenterology Unit, Department of Precision Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Giuseppe Imperio
- Hepatogastroenterology Unit, Department of Precision Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | | | - Maria Consiglia Trotta
- Department of Experimental Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Marcello Dallio
- Hepatogastroenterology Unit, Department of Precision Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Mario Romeo
- Hepatogastroenterology Unit, Department of Precision Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Michele D'Amico
- Department of Experimental Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Alessandro Federico
- Hepatogastroenterology Unit, Department of Precision Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| |
Collapse
|
10
|
Khouma A, Moeini MM, Plamondon J, Richard D, Caron A, Michael NJ. Histaminergic regulation of food intake. Front Endocrinol (Lausanne) 2023; 14:1202089. [PMID: 37448468 PMCID: PMC10338010 DOI: 10.3389/fendo.2023.1202089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/06/2023] [Indexed: 07/15/2023] Open
Abstract
Histamine is a biogenic amine that acts as a neuromodulator within the brain. In the hypothalamus, histaminergic signaling contributes to the regulation of numerous physiological and homeostatic processes, including the regulation of energy balance. Histaminergic neurons project extensively throughout the hypothalamus and two histamine receptors (H1R, H3R) are strongly expressed in key hypothalamic nuclei known to regulate energy homeostasis, including the paraventricular (PVH), ventromedial (VMH), dorsomedial (DMH), and arcuate (ARC) nuclei. The activation of different histamine receptors is associated with differential effects on neuronal activity, mediated by their different G protein-coupling. Consequently, activation of H1R has opposing effects on food intake to that of H3R: H1R activation suppresses food intake, while H3R activation mediates an orexigenic response. The central histaminergic system has been implicated in atypical antipsychotic-induced weight gain and has been proposed as a potential therapeutic target for the treatment of obesity. It has also been demonstrated to interact with other major regulators of energy homeostasis, including the central melanocortin system and the adipose-derived hormone leptin. However, the exact mechanisms by which the histaminergic system contributes to the modification of these satiety signals remain underexplored. The present review focuses on recent advances in our understanding of the central histaminergic system's role in regulating feeding and highlights unanswered questions remaining in our knowledge of the functionality of this system.
Collapse
Affiliation(s)
- Axelle Khouma
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, QC, Canada
- Faculté de Pharmacie, Université Laval, Québec, QC, Canada
| | - Moein Minbashi Moeini
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, QC, Canada
- Faculté de Pharmacie, Université Laval, Québec, QC, Canada
| | - Julie Plamondon
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, QC, Canada
| | - Denis Richard
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, QC, Canada
- Faculté de Medicine, Université Laval, Québec, QC, Canada
| | - Alexandre Caron
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, QC, Canada
- Faculté de Pharmacie, Université Laval, Québec, QC, Canada
- Montreal Diabetes Research Center, Montreal, QC, Canada
| | - Natalie Jane Michael
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, QC, Canada
- Faculté de Pharmacie, Université Laval, Québec, QC, Canada
| |
Collapse
|
11
|
Rocha A, Godino-Gimeno A, Rotllant J, Cerdá-Reverter JM. Agouti-Signalling Protein Overexpression Reduces Aggressiveness in Zebrafish. Biology (Basel) 2023; 12:biology12050712. [PMID: 37237525 DOI: 10.3390/biology12050712] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/21/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023]
Abstract
Feeding motivation plays a crucial role in food intake and growth. It closely depends on hunger and satiation, which are controlled by the melanocortin system. Overexpression of the inverse agonist agouti-signalling protein (ASIP) and agouti-related protein (AGRP) leads to enhanced food intake, linear growth, and weight. In zebrafish, overexpression of Agrp leads to the development of obesity, in contrast to the phenotype observed in transgenic zebrafish that overexpress asip1 under the control of a constitutive promoter (asip1-Tg). Previous studies have demonstrated that asip1-Tg zebrafish exhibit larger sizes but do not become obese. These fish display increased feeding motivation, resulting in a higher feeding rate, yet a higher food ration is not essential in order to grow larger than wild-type (WT) fish. This is most likely attributed to their improved intestinal permeability to amino acids and enhanced locomotor activity. A relationship between high feeding motivation and aggression has been previously reported in some other transgenic species showing enhanced growth. This study aims to elucidate whether the hunger observed in asip1-Tg is linked to aggressive behaviour. Dominance and aggressiveness were quantified using dyadic fights and mirror-stimulus tests, in addition to the analysis of basal cortisol levels. The results indicate that asip1-Tg are less aggressive than WT zebrafish in both dyadic fights and mirror-stimulus tests.
Collapse
Affiliation(s)
- Ana Rocha
- Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Alejandra Godino-Gimeno
- Control of Food Intake Group, Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, IATS-CSIC, 12595 Castellon, Spain
| | - Josep Rotllant
- Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (IIM-CSIC), 36208 Vigo, Spain
| | - José Miguel Cerdá-Reverter
- Control of Food Intake Group, Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, IATS-CSIC, 12595 Castellon, Spain
| |
Collapse
|
12
|
Xu Y, Jiang Z, Li H, Cai J, Jiang Y, Otiz-Guzman J, Xu Y, Arenkiel BR, Tong Q. Lateral septum as a melanocortin downstream site in obesity development. Cell Rep 2023; 42:112502. [PMID: 37171957 DOI: 10.1016/j.celrep.2023.112502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/27/2023] [Accepted: 04/26/2023] [Indexed: 05/14/2023] Open
Abstract
The melanocortin pathway is well established to be critical for body-weight regulation in both rodents and humans. Despite extensive studies focusing on this pathway, the downstream brain sites that mediate its action are not clear. Here, we found that, among the known paraventricular hypothalamic (PVH) neuron groups, those expressing melanocortin receptors 4 (PVHMc4R) preferably project to the ventral part of the lateral septum (LSv), a brain region known to be involved in emotional behaviors. Photostimulation of PVHMc4R neuron terminals in the LSv reduces feeding and causes aversion, whereas deletion of Mc4Rs or disruption of glutamate release from LSv-projecting PVH neurons causes obesity. In addition, disruption of AMPA receptor function in PVH-projected LSv neurons causes obesity. Importantly, chronic inhibition of PVH- or PVHMc4R-projected LSv neurons causes obesity associated with reduced energy expenditure. Thus, the LSv functions as an important node in mediating melanocortin action on body-weight regulation.
Collapse
Affiliation(s)
- Yuanzhong Xu
- Brown Foundation of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Zhiying Jiang
- Brown Foundation of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Hongli Li
- Brown Foundation of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Jing Cai
- Brown Foundation of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA; MD Anderson Cancer Center & UTHealth Houston Graduate School for Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yanyan Jiang
- Brown Foundation of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Joshua Otiz-Guzman
- Department of Molecular and Human Genetics and Department of Neuroscience, Baylor College of Medicine, and Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Benjamin R Arenkiel
- Department of Molecular and Human Genetics and Department of Neuroscience, Baylor College of Medicine, and Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Qingchun Tong
- Brown Foundation of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA; MD Anderson Cancer Center & UTHealth Houston Graduate School for Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Department of Neurobiology and Anatomy of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| |
Collapse
|
13
|
Semple EA, Harberson MT, Xu B, Rashleigh R, Cartwright TL, Braun JJ, Custer AC, Liu C, Hill JW. Melanocortin 4 receptor signaling in Sim1 neurons permits sexual receptivity in female mice. Front Endocrinol (Lausanne) 2023; 14:983670. [PMID: 37033219 PMCID: PMC10080118 DOI: 10.3389/fendo.2023.983670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/14/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction Female sexual dysfunction affects approximately 40% of women in the United States, yet few therapeutic options exist for these patients. The melanocortin system is a new treatment target for hypoactive sexual desire disorder (HSDD), but the neuronal pathways involved are unclear. Methods In this study, the sexual behavior of female MC4R knockout mice lacking melanocortin 4 receptors (MC4Rs) was examined. The mice were then bred to express MC4Rs exclusively on Sim1 neurons (tbMC4RSim1 mice) or on oxytocin neurons (tbMC4ROxt mice) to examine the effect on sexual responsiveness. Results MC4R knockout mice were found to approach males less and have reduced receptivity to copulation, as indicated by a low lordosis quotient. These changes were independent of body weight. Lordosis behavior was normalized in tbMC4RSim1 mice and improved in tbMC4ROxt mice. In contrast, approach behavior was unchanged in tbMC4RSim1 mice but greatly increased in tbMC4ROxt animals. The changes were independent of melanocortin-driven metabolic effects. Discussion These results implicate MC4R signaling in Oxt neurons in appetitive behaviors and MC4R signaling in Sim1 neurons in female sexual receptivity, while suggesting melanocortin-driven sexual function does not rely on metabolic neural circuits.
Collapse
Affiliation(s)
- Erin A. Semple
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Mitchell T. Harberson
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Baijie Xu
- Center for Hypothalamic Research, University of Texas Southwestern, Dallas, TX, United States
| | - Rebecca Rashleigh
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Tori L. Cartwright
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Jessica J. Braun
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Amy C. Custer
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Chen Liu
- Center for Hypothalamic Research, University of Texas Southwestern, Dallas, TX, United States
| | - Jennifer W. Hill
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
- Center for Diabetes and Endocrine Research, University of Toledo, Toledo, OH, United States
| |
Collapse
|
14
|
Khodeneva N, Sugimoto MA, Davan-Wetton CSA, Montero-Melendez T. Melanocortin therapies to resolve fibroblast-mediated diseases. Front Immunol 2023; 13:1084394. [PMID: 36793548 PMCID: PMC9922712 DOI: 10.3389/fimmu.2022.1084394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 11/28/2022] [Indexed: 02/01/2023] Open
Abstract
Stromal cells have emerged as central drivers in multiple and diverse diseases, and consequently, as potential new cellular targets for the development of novel therapeutic strategies. In this review we revise the main roles of fibroblasts, not only as structural cells but also as players and regulators of immune responses. Important aspects like fibroblast heterogeneity, functional specialization and cellular plasticity are also discussed as well as the implications that these aspects may have in disease and in the design of novel therapeutics. An extensive revision of the actions of fibroblasts on different conditions uncovers the existence of numerous diseases in which this cell type plays a pathogenic role, either due to an exacerbation of their 'structural' side, or a dysregulation of their 'immune side'. In both cases, opportunities for the development of innovative therapeutic approaches exist. In this regard, here we revise the existing evidence pointing at the melanocortin pathway as a potential new strategy for the treatment and management of diseases mediated by aberrantly activated fibroblasts, including scleroderma or rheumatoid arthritis. This evidence derives from studies involving models of in vitro primary fibroblasts, in vivo models of disease as well as ongoing human clinical trials. Melanocortin drugs, which are pro-resolving mediators, have shown ability to reduce collagen deposition, activation of myofibroblasts, reduction of pro-inflammatory mediators and reduced scar formation. Here we also discuss existing challenges, both in approaching fibroblasts as therapeutic targets, and in the development of novel melanocortin drug candidates, that may help advance the field and deliver new medicines for the management of diseases with high medical needs.
Collapse
|
15
|
Lavoie O, Michael NJ, Caron A. A critical update on the leptin- melanocortin system. J Neurochem 2023; 165:467-486. [PMID: 36648204 DOI: 10.1111/jnc.15765] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/25/2022] [Accepted: 01/09/2023] [Indexed: 01/18/2023]
Abstract
The discovery of leptin in 1994 was an "eureka moment" in the field of neurometabolism that provided new opportunities to better understand the central control of energy balance and glucose metabolism. Rapidly, a prevalent model in the field emerged that pro-opiomelanocortin (POMC) neurons were key in promoting leptin's anorexigenic effects and that the arcuate nucleus of the hypothalamus (ARC) was a key region for the regulation of energy homeostasis. While this model inspired many important discoveries, a growing body of literature indicates that this model is now outdated. In this review, we re-evaluate the hypothalamic leptin-melanocortin model in light of recent advances that directly tackle previous assumptions, with a particular focus on the ARC. We discuss how segregated and heterogeneous these neurons are, and examine how the development of modern approaches allowing spatiotemporal, intersectional, and chemogenetic manipulations of melanocortin neurons has allowed a better definition of the complexity of the leptin-melanocortin system. We review the importance of leptin in regulating glucose homeostasis, but not food intake, through direct actions on ARC POMC neurons. We further highlight how non-POMC, GABAergic neurons mediate leptin's direct effects on energy balance and influence POMC neurons.
Collapse
Affiliation(s)
- Olivier Lavoie
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada
| | - Natalie Jane Michael
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada
| | - Alexandre Caron
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada.,Montreal Diabetes Research Center, Montreal, Quebec, Canada
| |
Collapse
|
16
|
Dodd J, Jordan R, Makhlina M, Barnett K, Roffel A, Spana C, Obr A, Dhingra P, Kayne PS. A novel oral formulation of the melanocortin-1 receptor agonist PL8177 resolves inflammation in preclinical studies of inflammatory bowel disease and is gut restricted in rats, dogs, and humans. Front Immunol 2023; 14:1083333. [PMID: 36891301 PMCID: PMC9986545 DOI: 10.3389/fimmu.2023.1083333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/31/2023] [Indexed: 02/22/2023] Open
Abstract
Introduction PL8177 is a potent and selective agonist of the melanocortin 1 receptor (MC1R). PL8177 has shown efficacy in reversing intestinal inflammation in a cannulated rat ulcerative colitis model. To facilitate oral delivery, a novel, polymer-encapsulated formulation of PL8177 was developed. This formulation was tested in 2 rat ulcerative colitis models and evaluated for distribution, in vivo, in rats, dogs, and humans. Methods The rat models of colitis were induced by treatment with 2,4-dinitrobenzenesulfonic acid or dextran sulfate sodium. Single nuclei RNA sequencing of colon tissues was performed to characterize the mechanism of action. The distribution and concentration of PL8177 and the main metabolite within the GI tract after a single oral dose of PL8177 was investigated in rats and dogs. A phase 0 clinical study using a single microdose (70 µg) of [14C]-labeled PL8177 investigated the release of PL8177 in the colon of healthy men after oral administration. Results Rats treated with 50 µg oral PL8177 demonstrated significantly lower macroscopic colon damage scores and improvement in colon weight, stool consistency, and fecal occult blood vs the vehicle without active drug. Histopathology analysis resulted in the maintenance of intact colon structure and barrier, reduced immune cell infiltration, and increased enterocytes with PL8177 treatment. Transcriptome data show that oral PL8177 50 µg treatment causes relative cell populations and key gene expressions levels to move closer to healthy controls. Compared with vehicle, treated colon samples show negative enrichment of immune marker genes and diverse immune-related pathways. In rats and dogs, orally administered PL8177 was detected at higher amounts in the colon vs upper GI tract. [14C]-PL8177 and the main metabolite were detected in the feces but not in the plasma and urine in humans. This suggests that the parent drug [14C]-PL8177 was released from the polymer formulation and metabolized within the GI tract, where it would be expected to exert its effect. Conclusion Collectively, these findings support further research into the oral formulation of PL8177 as a possible therapeutic for GI inflammatory diseases in humans.
Collapse
Affiliation(s)
- John Dodd
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | - Robert Jordan
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | | | - Keith Barnett
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | - Ad Roffel
- Consulting & Advisory Services - Clinical Pharmacology, ICON plc, Groningen, Netherlands
| | - Carl Spana
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | - Alison Obr
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | | | - Paul S Kayne
- Palatin Technologies, Inc., Cranbury, NJ, United States
| |
Collapse
|
17
|
Bedenbaugh MN, Brener SC, Maldonado J, Lippert RN, Sweeney P, Cone RD, Simerly RB. Organization of neural systems expressing melanocortin-3 receptors in the mouse brain: Evidence for sexual dimorphism. J Comp Neurol 2022; 530:2835-2851. [PMID: 35770983 PMCID: PMC9724692 DOI: 10.1002/cne.25379] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/24/2022] [Accepted: 05/27/2022] [Indexed: 01/13/2023]
Abstract
The central melanocortin system is fundamentally important for controlling food intake and energy homeostasis. Melanocortin-3 receptor (MC3R) is one of two major receptors of the melanocortin system found in the brain. In contrast to the well-characterized melanocortin-4 receptor (MC4R), little is known regarding the organization of MC3R-expressing neural circuits. To increase our understanding of the intrinsic organization of MC3R neural circuits, identify specific differences between males and females, and gain a neural systems level perspective of this circuitry, we conducted a brain-wide mapping of neurons labeled for MC3R and characterized the distribution of their projections. Analysis revealed MC3R neuronal and terminal labeling in multiple brain regions that control a diverse range of physiological functions and behavioral processes. Notably, dense labeling was observed in the hypothalamus, as well as areas that share considerable connections with the hypothalamus, including the cortex, amygdala, thalamus, and brainstem. Additionally, MC3R neuronal labeling was sexually dimorphic in several areas, including the anteroventral periventricular area, arcuate nucleus, principal nucleus of the bed nucleus of the stria terminalis, and ventral premammillary region. Altogether, anatomical evidence reported here suggests that MC3R has the potential to influence several different classes of motivated behavior that are essential for survival, including ingestive, reproductive, defensive, and arousal behaviors, and is likely to modulate these behaviors differently in males and females.
Collapse
Affiliation(s)
- Michelle N. Bedenbaugh
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Samantha C. Brener
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Jose Maldonado
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Rachel N. Lippert
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Potsdam, Germany
| | - Patrick Sweeney
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular and Integrative Physiology, School of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Roger D. Cone
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular and Integrative Physiology, School of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Richard B. Simerly
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| |
Collapse
|
18
|
Islam MT, Rumpf F, Tsuno Y, Kodani S, Sakurai T, Matsui A, Maejima T, Mieda M. Vasopressin neurons in the paraventricular hypothalamus promote wakefulness via lateral hypothalamic orexin neurons. Curr Biol 2022; 32:3871-3885.e4. [PMID: 35907397 DOI: 10.1016/j.cub.2022.07.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 06/11/2022] [Accepted: 07/08/2022] [Indexed: 01/25/2023]
Abstract
The sleep-wakefulness cycle is regulated by complicated neural networks that include many different populations of neurons throughout the brain. Arginine vasopressin neurons in the paraventricular nucleus of the hypothalamus (PVHAVP) regulate various physiological events and behaviors, such as body-fluid homeostasis, blood pressure, stress response, social interaction, and feeding. Changes in arousal level often accompany these PVHAVP-mediated adaptive responses. However, the contribution of PVHAVP neurons to sleep-wakefulness regulation has remained unknown. Here, we report the involvement of PVHAVP neurons in arousal promotion. Optogenetic stimulation of PVHAVP neurons rapidly induced transitions to wakefulness from both NREM and REM sleep. This arousal effect was dependent on AVP expression in these neurons. Similarly, chemogenetic activation of PVHAVP neurons increased wakefulness and reduced NREM and REM sleep, whereas chemogenetic inhibition of these neurons significantly reduced wakefulness and increased NREM sleep. We observed dense projections of PVHAVP neurons in the lateral hypothalamus with potential connections to orexin/hypocretin (LHOrx) neurons. Optogenetic stimulation of PVHAVP neuronal fibers in the LH immediately induced wakefulness, whereas blocking orexin receptors attenuated the arousal effect of PVHAVP neuronal activation drastically. Monosynaptic rabies-virus tracing revealed that PVHAVP neurons receive inputs from multiple brain regions involved in sleep-wakefulness regulation, as well as those involved in stress response and energy metabolism. Moreover, PVHAVP neurons mediated the arousal induced by novelty stress and a melanocortin receptor agonist melanotan-II. Thus, our data suggested that PVHAVP neurons promote wakefulness via LHOrx neurons in the basal sleep-wakefulness and some stressful conditions.
Collapse
Affiliation(s)
- Md Tarikul Islam
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Florian Rumpf
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan; Graduate School of Life Sciences, University of Würzburg, Beatrice-Edgell-Weg 21, 97074 Würzburg, Germany
| | - Yusuke Tsuno
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Shota Kodani
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Takeshi Sakurai
- Faculty of Medicine/WPI-IIIS, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Ayako Matsui
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Takashi Maejima
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan.
| |
Collapse
|
19
|
Oliveira V, Riedl RA, Claflin KE, Mathieu NM, Ritter ML, Balapattabi K, Wackman KK, Reho JJ, Brozoski DT, Morgan DA, Cui H, Rahmouni K, Burnett CML, Nakagawa P, Sigmund CD, Morselli LL, Grobe JL. Melanocortin MC 4R receptor is required for energy expenditure but not blood pressure effects of angiotensin II within the mouse brain. Physiol Genomics 2022; 54:196-205. [PMID: 35476598 PMCID: PMC9131927 DOI: 10.1152/physiolgenomics.00015.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The brain renin-angiotensin system (RAS) is implicated in control of blood pressure (BP), fluid intake, and energy expenditure (EE). Angiotensin II (ANG II) within the arcuate nucleus of the hypothalamus contributes to control of resting metabolic rate (RMR) and thereby EE through its actions on Agouti-related peptide (AgRP) neurons, which also contribute to EE control by leptin. First, we determined that although leptin stimulates EE in control littermates, mice with transgenic activation of the brain RAS (sRA) exhibit increased EE and leptin has no additive effect to exaggerate EE in these mice. These findings led us to hypothesize that leptin and ANG II in the brain stimulate EE through a shared mechanism. Because AgRP signaling to the melanocortin MC4R receptor contributes to the metabolic effects of leptin, we performed a series of studies examining RMR, fluid intake, and BP responses to ANG II in mice rendered deficient for expression of MC4R via a transcriptional block (Mc4r-TB). These mice were resistant to stimulation of RMR in response to activation of the endogenous brain RAS via chronic deoxycorticosterone acetate (DOCA)-salt treatment, whereas fluid and electrolyte effects remained intact. These mice were also resistant to stimulation of RMR via acute intracerebroventricular (ICV) injection of ANG II, whereas BP responses to ICV ANG II remained intact. Collectively, these data demonstrate that the effects of ANG II within the brain to control RMR and EE are dependent on MC4R signaling, whereas fluid homeostasis and BP responses are independent of MC4R signaling.
Collapse
Affiliation(s)
- Vanessa Oliveira
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ruth A. Riedl
- 2Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Kristin E. Claflin
- 3Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa
| | - Natalia M. Mathieu
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - McKenzie L. Ritter
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | | | - Kelsey K. Wackman
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - John J. Reho
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin,4Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Daniel T. Brozoski
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Donald A. Morgan
- 3Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa
| | - Huxing Cui
- 3Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa,5Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
| | - Kamal Rahmouni
- 3Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa,5Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa,6Department of Internal Medicine, University of Iowa, Iowa City, Iowa,7Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa,8Iowa City Veterans Affairs Health Care System, Iowa City, Iowa
| | | | - Pablo Nakagawa
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin,9Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Curt D. Sigmund
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin,9Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin,10Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Lisa L. Morselli
- 11Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Justin L. Grobe
- 1Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin,4Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin,9Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin,10Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin,12Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin
| |
Collapse
|
20
|
Spana C, Jordan R, Fischkoff S. Effect of bremelanotide on body weight of obese women: Data from two phase 1 randomized controlled trials. Diabetes Obes Metab 2022; 24:1084-1093. [PMID: 35170192 PMCID: PMC9314948 DOI: 10.1111/dom.14672] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/04/2022] [Accepted: 02/13/2022] [Indexed: 11/30/2022]
Abstract
AIMS The melanocortin 4 receptor (MC4R) plays a central role in appetite regulation, and agonistic activity at this receptor promotes satiety. Results from two randomized controlled clinical trials examine the effects of bremelanotide's agonism at MC4R on caloric intake and body weight. METHODS Premenopausal women with a body mass index >30 kg/m2 were studied in two phase 1, single-centre, randomized, double-blind, placebo-controlled trials. Study A matched subjects 1:1 to receive subcutaneous placebo or bremelanotide three times daily for days 1-15. Study B was a crossover trial with six distinct treatment sequences consisting of three 4-day treatment periods, investigating once-a-day and twice-a-day exposure to bremelanotide versus placebo. Subjects received one of the three treatments twice-daily during each period: 0 mg/0 mg, 2.5 mg/0 mg or 2.5 mg/2.0 mg bremelanotide. Body weight and food intake were recorded in detail daily. Adverse events were recorded throughout both studies. RESULTS In Study A, 27 of 30 bremelanotide subjects (90.0%) completed the trial and exhibited a significantly greater reduction in body weight after 16 days versus placebo [least squares mean difference (95% CI), -1.3 (-1.9 to -0.8) kg; p < .0001]. Mean caloric intake in bremelanotide subjects was decreased versus placebo, with a magnitude of reduction of approximately 400 kcal/day throughout Study A (p < .01). In Study B, 15 of 27 subjects (55.6%) completed all three phases. Significantly greater reduction of mean body weight occurred in twice-daily bremelanotide subjects versus placebo (1.7 vs. 0.9 kg, respectively, p < .001). Total caloric intake reduction was significantly greater in the bremelanotide groups versus placebo (mean difference range: 398-469 kcal; p < .0001). CONCLUSIONS Agonist activity at the MC4R may aid in reducing caloric intake and weight loss in obese women.
Collapse
Affiliation(s)
- Carl Spana
- Palatin Technologies, Inc.CranburyNew JerseyUSA
| | | | | |
Collapse
|
21
|
Abstract
Obesity is a disease of the nervous system. While some will view this statement as provocative, others will take it as obvious. Whatever our side is, the pharmacology tells us that targeting the nervous system works for promoting weight loss. It works, but at what cost? Is the nervous system a safe target for sustainable treatment of obesity? What have we learned-and unlearned-about the central control of energy balance in the last few years? Herein we provide a thought-provoking exploration of obesity as a disorder of neurotransmission. We discuss the state of knowledge on the brain pathways regulating energy homeostasis that are commonly targeted in anti-obesity therapy and explore how medications affecting neurotransmission such as atypical antipsychotics, antidepressants, and antihistamines relate to body weight. Our goal is to provide the endocrine community with a conceptual framework that will help expending our understanding of the pathophysiology of obesity, a disease of the nervous system.
Collapse
Affiliation(s)
- Alexandre Caron
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
- Montreal Diabetes Research Center, Montreal, QC, Canada
| | - Natalie Jane Michael
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
| |
Collapse
|
22
|
Affiliation(s)
| | - Kate Evans
- University Hospitals Plymouth NHS Trust, Plymouth, UK
| |
Collapse
|
23
|
Quante M, Iske J, Heinbokel T, Desai BN, Cetina Biefer HR, Nian Y, Krenzien F, Matsunaga T, Uehara H, Maenosono R, Azuma H, Pratschke J, Falk CS, Lo T, Sheu E, Tavakkoli A, Abdi R, Perkins D, Alegre ML, Banks AS, Zhou H, Elkhal A, Tullius SG. Restored TDCA and valine levels imitate the effects of bariatric surgery. eLife 2021; 10:e62928. [PMID: 34155969 PMCID: PMC8257250 DOI: 10.7554/elife.62928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 05/20/2021] [Indexed: 12/12/2022] Open
Abstract
Background Obesity is widespread and linked to various co-morbidities. Bariatric surgery has been identified as the only effective treatment, promoting sustained weight loss and the remission of co-morbidities. Methods Metabolic profiling was performed on diet-induced obese (DIO) mice, lean mice, and DIO mice that underwent sleeve gastrectomies (SGx). In addition, mice were subjected to intraperitoneal (i.p.) injections with taurodeoxycholic acid (TDCA) and valine. Indirect calorimetry was performed to assess food intake and energy expenditure. Expression of appetite-regulating hormones was assessed through quantification of isolated RNA from dissected hypothalamus tissue. Subsequently, i.p. injections with a melanin-concentrating hormone (MCH) antagonist and intrathecal administration of MCH were performed and weight loss was monitored. Results Mass spectrometric metabolomic profiling revealed significantly reduced systemic levels of TDCA and L-valine in DIO mice. TDCA and L-valine levels were restored after SGx in both human and mice to levels comparable with lean controls. Systemic treatment with TDCA and valine induced a profound weight loss analogous to effects observed after SGx. Utilizing indirect calorimetry, we confirmed reduced food intake as causal for TDCA/valine-mediated weight loss via a central inhibition of the MCH. Conclusions In summary, we identified restored TDCA/valine levels as an underlying mechanism of SGx-derived effects on weight loss. Of translational relevance, TDCA and L-valine are presented as novel agents promoting weight loss while reversing obesity-associated metabolic disorders. Funding This work has been supported in part by a grant from NIH (UO-1 A1 132898 to S.G.T., DP and MA). M.Q. was supported by the IFB Integrated Research and Treatment Centre Adiposity Diseases (Leipzig, Germany) and the German Research Foundation (QU 420/1-1). J.I. was supported by the Biomedical Education Program (BMEP) of the German Academic Exchange Service (DAAD). T.H. (HE 7457/1-1) and F.K. (KR 4362/1-1) were supported by the German Research Foundation (DFG). H.R.C.B. was supported the Swiss Society of Cardiac Surgery. Y.N. was supported by the Chinese Scholarship Council (201606370196) and Central South University. H.U., T.M. and R.M. were supported by the Osaka Medical Foundation. C.S.F. was supported by the German Research Foundation (DFG, SFB738, B3).
Collapse
Affiliation(s)
- Markus Quante
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Department of General, Visceral and Transplant Surgery, University Hospital TübingenTübingenGermany
| | - Jasper Iske
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Institute of Transplant Immunology, Hannover Medical SchoolHannover, Lower SaxonyGermany
| | - Timm Heinbokel
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Department of Pathology, Charité Universitätsmedizin BerlinBerlinGermany
| | - Bhavna N Desai
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical CenterBostonUnited States
| | - Hector Rodriguez Cetina Biefer
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Department of Cardiovascular Surgery, Charité Universitätsmedizin BerlinBerlinGermany
| | - Yeqi Nian
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Department of Urology, The Second Xiangya Hospital, Central South UniversityChangshaChina
| | - Felix Krenzien
- Department of Visceral, Abdominal and Transplantation Surgery, Charité Universitätsmedizin BerlinBerlinGermany
| | - Tomohisa Matsunaga
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Department of Urology, Faculty of Medicine, Osaka Medical and Pharmaceutical UniversityOsakaJapan
| | - Hirofumi Uehara
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Department of Urology, Faculty of Medicine, Osaka Medical and Pharmaceutical UniversityOsakaJapan
| | - Ryoichi Maenosono
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
- Department of Urology, Faculty of Medicine, Osaka Medical and Pharmaceutical UniversityOsakaJapan
| | - Haruhito Azuma
- Department of Urology, Faculty of Medicine, Osaka Medical and Pharmaceutical UniversityOsakaJapan
| | - Johann Pratschke
- Department of Visceral, Abdominal and Transplantation Surgery, Charité Universitätsmedizin BerlinBerlinGermany
| | - Christine S Falk
- Institute of Transplant Immunology, Hannover Medical SchoolHannover, Lower SaxonyGermany
| | - Tammy Lo
- Division of Gastrointestinal and General Surgery, Department of Surgery, Brigham and Women’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Eric Sheu
- Division of Gastrointestinal and General Surgery, Department of Surgery, Brigham and Women’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Ali Tavakkoli
- Division of Gastrointestinal and General Surgery, Department of Surgery, Brigham and Women’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Reza Abdi
- Renal Division, Brigham and Women’s Hospital, Harvard Medical SchoolBostonUnited States
| | - David Perkins
- Division of Nephrology, Department of Medicine, University of Illinois at ChicagoChicagoUnited States
| | - Maria-Luisa Alegre
- Department of Medicine, Section of Rheumatology, The University of ChicagoChicagoUnited States
| | - Alexander S Banks
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical CenterBostonUnited States
| | - Hao Zhou
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
| | - Abdallah Elkhal
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
| | - Stefan G Tullius
- Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical SchoolBostonUnited States
| |
Collapse
|
24
|
Fortin SM, Chen J, Grill HJ, Hayes MR. The Mesencephalic Trigeminal Nucleus Controls Food Intake and Body Weight via Hindbrain POMC Projections. Nutrients 2021; 13:nu13051642. [PMID: 34068091 PMCID: PMC8152732 DOI: 10.3390/nu13051642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/30/2021] [Accepted: 05/10/2021] [Indexed: 12/20/2022] Open
Abstract
The mesencephalic trigeminal nucleus (Mes5) processes oral sensory–motor information, but its role in the control of energy balance remains unexplored. Here, using fluorescent in situ hybridization, we show that the Mes5 expresses the melanocortin-4 receptor. Consistent with MC4R activation in other areas of the brain, we found that Mes5 microinjection of the MC4R agonist melanotan-II (MTII) suppresses food intake and body weight in the mouse. Furthermore, NTS POMC-projecting neurons to the Mes5 can be chemogenetically activated to drive a suppression in food intake. Taken together, these findings highlight the Mes5 as a novel target of melanocortinergic control of food intake and body weight regulation, although elucidating the endogenous role of this circuit requires future study. While we observed the sufficiency of Mes5 MC4Rs for food intake and body weight suppression, these receptors do not appear to be necessary for food intake or body weight control. Collectively, the data presented here support the functional relevance of the NTS POMC to Mes5 projection pathway as a novel circuit that can be targeted to modulate food intake and body weight.
Collapse
Affiliation(s)
- Samantha M. Fortin
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.F.); (J.C.)
| | - Jack Chen
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.F.); (J.C.)
| | - Harvey J. Grill
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Matthew R. Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.F.); (J.C.)
- Correspondence:
| |
Collapse
|
25
|
Brouwers B, de Oliveira EM, Marti-Solano M, Monteiro FBF, Laurin SA, Keogh JM, Henning E, Bounds R, Daly CA, Houston S, Ayinampudi V, Wasiluk N, Clarke D, Plouffe B, Bouvier M, Babu MM, Farooqi IS, Mokrosiński J. Human MC4R variants affect endocytosis, trafficking and dimerization revealing multiple cellular mechanisms involved in weight regulation. Cell Rep 2021; 34:108862. [PMID: 33761344 PMCID: PMC7994375 DOI: 10.1016/j.celrep.2021.108862] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/29/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022] Open
Abstract
The Melanocortin-4 Receptor (MC4R) plays a pivotal role in energy homeostasis. We used human MC4R mutations associated with an increased or decreased risk of obesity to dissect mechanisms that regulate MC4R function. Most obesity-associated mutations impair trafficking to the plasma membrane (PM), whereas obesity-protecting mutations either accelerate recycling to the PM or decrease internalization, resulting in enhanced signaling. MC4R mutations that do not affect canonical Gαs protein-mediated signaling, previously considered to be non-pathogenic, nonetheless disrupt agonist-induced internalization, β-arrestin recruitment, and/or coupling to Gαs, establishing their causal role in severe obesity. Structural mapping reveals ligand-accessible sites by which MC4R couples to effectors and residues involved in the homodimerization of MC4R, which is disrupted by multiple obesity-associated mutations. Human genetic studies reveal that endocytosis, intracellular trafficking, and homodimerization regulate MC4R function to a level that is physiologically relevant, supporting the development of chaperones, agonists, and allosteric modulators of MC4R for weight loss therapy.
Collapse
Affiliation(s)
- Bas Brouwers
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Edson Mendes de Oliveira
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | | | - Fabiola B F Monteiro
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Suli-Anne Laurin
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Julia M Keogh
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Elana Henning
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Rebecca Bounds
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Carole A Daly
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Shane Houston
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Vikram Ayinampudi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Natalia Wasiluk
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - David Clarke
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Bianca Plouffe
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Michel Bouvier
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - M Madan Babu
- MRC Laboratory of Molecular Biology, Cambridge, UK; Department of Structural Biology and Center for Data Driven Discovery, St Jude Children's Research Hospital, Memphis, TN, USA
| | - I Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
| | - Jacek Mokrosiński
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| |
Collapse
|
26
|
Kuhre RE, Modvig IM, Jepsen SL, Kizilkaya HS, Bæch-Laursen C, Smith CA, Reimann F, Gribble FM, Rosenkilde MM, Holst JJ. L-Cell Expression of Melanocortin-4-Receptor Is Marginal in Most of the Small Intestine in Mice and Humans and Direct Stimulation of Small Intestinal Melanocortin-4-Receptors in Mice and Rats Does Not Affect GLP-1 Secretion. Front Endocrinol (Lausanne) 2021; 12:690387. [PMID: 34421821 PMCID: PMC8375664 DOI: 10.3389/fendo.2021.690387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/18/2021] [Indexed: 11/17/2022] Open
Abstract
The molecular sensors underlying nutrient-stimulated GLP-1 secretion are currently being investigated. Peripheral administration of melanocortin-4 receptor (MC4R) agonists have been reported to increase GLP-1 plasma concentrations in mice and humans but it is unknown whether this effect results from a direct effect on the GLP-1 secreting L-cells in the intestine, from other effects in the intestine or from extra-intestinal effects. We investigated L-cell expression of MC4R in mouse and human L-cells by reanalyzing publicly available RNA sequencing databases (mouse and human) and by RT-qPCR (mouse), and assessed whether administration of MC4R agonists to a physiologically relevant gut model, isolated perfused mouse and rat small intestine, would stimulate GLP-1 secretion or potentiate glucose-stimulated secretion. L-cell MC4R expression was low in mouse duodenum and hardly detectable in the ileum and MC4R expression was hardly detectable in human L-cells. In isolated perfused mouse and rat intestine, neither intra-luminal nor intra-arterial administration of NDP-alpha-MSH, a potent MC4R agonist, had any effect on GLP-1 secretion (P ≥0.98, n = 5-6) from the upper or lower-half of the small intestine in mice or in the lower half in rats. Furthermore, HS014-an often used MC4R antagonist, which we found to be a partial agonist-did not affect the glucose-induced GLP-1 response in the rat, P = 0.62, n = 6). Studies on transfected COS7-cells confirmed bioactivity of the used compounds and that concentrations employed were well within in the effective range. Our combined data therefore suggest that MC4R-activated GLP-1 secretion in rodents either exclusively occurs in the colon or involves extra-intestinal signaling.
Collapse
Affiliation(s)
- Rune E. Kuhre
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Obesity Pharmacology, Novo Nordisk, Måløv, Denmark
- *Correspondence: Rune E. Kuhre, ; Jens J. Holst,
| | - Ida M. Modvig
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sara L. Jepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hüsün S. Kizilkaya
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cecilie Bæch-Laursen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christopher A. Smith
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Frank Reimann
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Fiona M. Gribble
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Mette M. Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J. Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Rune E. Kuhre, ; Jens J. Holst,
| |
Collapse
|
27
|
Sharfman N, Gilpin NW. The Role of Melanocortin Plasticity in Pain-Related Outcomes After Alcohol Exposure. Front Psychiatry 2021; 12:764720. [PMID: 34803772 PMCID: PMC8599269 DOI: 10.3389/fpsyt.2021.764720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/05/2021] [Indexed: 11/13/2022] Open
Abstract
The global COVID-19 pandemic has shone a light on the rates and dangers of alcohol misuse in adults and adolescents in the US and globally. Alcohol exposure during adolescence causes persistent molecular, cellular, and behavioral changes that increase the risk of alcohol use disorder (AUD) into adulthood. It is established that alcohol abuse in adulthood increases the likelihood of pain hypersensitivity and the genesis of chronic pain, and humans report drinking alcohol to relieve pain symptoms. However, the longitudinal effects of alcohol exposure on pain and the underlying CNS signaling that mediates it are understudied. Specific brain regions mediate pain effects, alcohol effects, and pain-alcohol interactions, and neural signaling in those brain regions is modulated by neuropeptides. The CNS melanocortin system is sensitive to alcohol and modulates pain sensitivity, but this system is understudied in the context of pain-alcohol interactions. In this review, we focus on the role of melanocortin signaling in brain regions sensitive to alcohol and pain, in particular the amygdala. We also discuss interactions of melanocortins with other peptide systems, including the opioid system, as potential mediators of pain-alcohol interactions. Therapeutic strategies that target the melanocortin system may mitigate the negative consequences of alcohol misuse during adolescence and/or adulthood, including effects on pain-related outcomes.
Collapse
Affiliation(s)
- Nathan Sharfman
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Nicholas W Gilpin
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Alcohol and Drug Abuse Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Southeast Louisiana VA Healthcare System (SLVHCS), New Orleans, LA, United States
| |
Collapse
|
28
|
McMillan TR, Forster MAM, Short LI, Rudecki AP, Cline DL, Gray SL. Melanotan II, a melanocortin agonist, partially rescues the impaired thermogenic capacity of pituitary adenylate cyclase-activating polypeptide deficient mice. Exp Physiol 2020; 106:427-437. [PMID: 33332767 DOI: 10.1113/ep088838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 11/27/2020] [Indexed: 12/16/2022]
Abstract
NEW FINDINGS What is the central question of this study? Can chronic treatment of pituitary adenylate cyclase-activating polypeptide (PACAP) deficient mice with the melanocortin agonist melanotan II during cold acclimation rescue the impaired thermogenic capacity previously observed in PACAP deficient mice? What is the main finding and its importance? Using a genetic model of PACAP deficiency, this study provides evidence that PACAP acts upstream of the melanocortin system in regulating sympathetic nerve activity to brown adipose tissue in mice. ABSTRACT Impaired adipose tissue function in obesity, including reduced thermogenic potential, has detrimental consequences for metabolic health. Hormonal regulation of adaptive thermogenesis is being explored as a potential therapeutic target for human obesity. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide expressed in nuclei of the hypothalamus known to regulate energy expenditure, and functional studies reveal a role for PACAP in the central regulation of thermogenesis, although mechanisms are not well understood. We hypothesized that PACAP acts upstream of the melanocortin system to regulate sympathetic nerve activity to stimulate thermogenesis. To assess this, female PACAP-/- and PACAP+/+ mice were given daily peripheral injections of a melanocortin receptor agonist, melanotan II (MTII), for 3 weeks during cold acclimation, and the effect of MTII on thermogenic capacity and adipose tissue remodelling was examined by physiological and histological analyses. MTII partially rescued the impaired thermogenic capacity in PACAP-/- mice as compared to PACAP+/+ mice as determined by measuring noradrenaline-induced metabolic rate. In addition, MTII treatment during cold acclimation corrected the previously identified deficit in lipid utilization in response to adrenergic stimulation in PACAP-/- null mice, suggesting impaired lipid mobilization may contribute to the impaired thermogenic capacity of PACAP-/- mice. Results presented here provide physiological evidence to suggest that PACAP acts upstream of melanocortin receptors to facilitate sympathetically induced mechanisms of adaptive thermogenesis in response to cold acclimation.
Collapse
Affiliation(s)
- Thecla Rae McMillan
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Maeghan A M Forster
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Landon I Short
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Alexander P Rudecki
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Daemon L Cline
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Sarah L Gray
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| |
Collapse
|
29
|
Abstract
Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) plays an essential role in the control of food intake and energy expenditure. Melanocortin-4 receptors (MC4Rs) are expressed in key areas that are implicated in regulating energy homeostasis. Although the importance of MC4Rs in the paraventricular hypothalamus (PVH) has been well documented, the role of MC4Rs in the medial amygdala (MeA) on feeding remains controversial. In this study, we specifically examine the role of a novel ARCPOMC→MeA neural circuit in the regulation of short-term food intake. To map a local melanocortinergic neural circuit, we use monosynaptic anterograde as well as retrograde viral tracers and perform double immunohistochemistry to determine the identity of the neurons receiving synaptic input from POMC neurons in the ARC. To investigate the role of the ARCPOMC→MeA projection on feeding, we optogenetically stimulate channelrhodopsin-2 (ChR2)-expressing POMC fibers in the MeA. Anterograde viral tracing studies reveal that ARC POMC neurons send axonal projections to estrogen receptor-α (ER-α)- and MC4R-expressing neurons in the MeA. Retrograde viral tracing experiments show that the neurons projecting to the MeA is located mainly in the lateral part of the ARC. Optogenetic stimulation of the ARCPOMC→MeA pathway reduces short-term food intake. This anorectic effect is blocked by treatment with the MC4R antagonist SHU9119. In addition to the melanocortinergic local circuits within the hypothalamus, this extrahypothalamic ARCPOMC→MeA neural circuit would play a role in regulating short-term food intake.
Collapse
Affiliation(s)
- Eunjin Kwon
- The Fleischer Institute for Diabetes and Metabolism, Bronx, NY, United States
- Division of Endocrinology, Department of Medicine, Bronx, NY, United States
| | - Young-Hwan Jo
- The Fleischer Institute for Diabetes and Metabolism, Bronx, NY, United States
- Division of Endocrinology, Department of Medicine, Bronx, NY, United States
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| |
Collapse
|
30
|
Godino-Gimeno A, Sánchez E, Guillot R, Rocha A, Angotzi AR, Leal E, Rotllant J, Cerdá-Reverter JM. Growth Performance After Agouti-Signaling Protein 1 ( Asip1) Overexpression in Transgenic Zebrafish. Zebrafish 2020; 17:373-381. [PMID: 33112719 DOI: 10.1089/zeb.2020.1932] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The melanocortin system is a key structure in the regulation of energy balance. Overexpression of inverse agonists, agouti-signaling protein (ASIP), and agouti-related protein (AGRP) results in increased food intake, linear growth, and body weight. ASIP regulates dorsal-ventral pigment polarity through melanocortin 1 receptor (MC1R) and overexpression induces obesity in mice by binding to central MC4R. Asip1 overexpression in transgenic zebrafish (asip1-Tg) enhances growth, yet experiments show fish overexpressing Asip1 do not develop obesity even under severe feeding regimes. Asip1-Tg fish do not need to eat more to grow larger and faster; thus, increased food efficiency can be observed. In addition, asip1-Tg fish reared at high density are able to grow far more than wild-type (WT) fish reared at low density, although asip1-Tg fish seem to be more sensitive to crowding stress than WT fish, thus making the melanocortin system a target for sustainable aquaculture, especially as the U.S. Food and Drug Association has recently approved transgenic fish trading.
Collapse
Affiliation(s)
- Alejandra Godino-Gimeno
- Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellon, Spain
| | - Elisa Sánchez
- Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellon, Spain
| | - Raúl Guillot
- Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellon, Spain
| | - Ana Rocha
- Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Matosinhos, Portugal.,MARE - Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria, Peniche, Portugal
| | - Anna Rita Angotzi
- Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellon, Spain
| | - Esther Leal
- Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellon, Spain
| | - Josep Rotllant
- Department of Biotechnology and Aquaculture, Instituto de Investigaciones Marinas, IIM-CSIC, Vigo, Spain
| | - José Miguel Cerdá-Reverter
- Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellon, Spain
| |
Collapse
|
31
|
Berruien NNA, Smith CL. Emerging roles of melanocortin receptor accessory proteins (MRAP and MRAP2) in physiology and pathophysiology. Gene 2020; 757:144949. [PMID: 32679290 DOI: 10.1016/j.gene.2020.144949] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/08/2020] [Accepted: 07/09/2020] [Indexed: 01/07/2023]
Abstract
Melanocortin-2 receptor accessory protein (MRAP) has an unusual dual topology and influences the expression, localisation, signalling and internalisation of the melanocortin receptor 2 (MC2); the adrenocorticotropic hormone (ACTH) receptor. Mutations in MRAP are associated with familial glucocorticoid deficiency type-2 and evidence is emerging of the importance of MRAP in adrenal development and ACTH signalling. Human MRAP has two functional splice variants: MRAP-α and MRAP-β, unlike MRAP-β, MRAP-α has little expression in brain but is highly expressed in ovary. MRAP2, identified through whole human genome sequence analysis, has approximately 40% sequence homology to MRAP. MRAP2 facilitates MC2 localisation to the cell surface but not ACTH signalling. MRAP and MRAP2 have been found to regulate the surface expression and signalling of all melanocortin receptors (MC1-5). Additionally, MRAP2 moderates the signalling of the G-protein coupled receptors (GCPRs): orexin, prokineticin and GHSR1a; the ghrelin receptor. Whilst MRAP appears to be mainly involved in glucocorticoid synthesis, an important role is emerging for MRAP2 in regulating appetite and energy homeostasis. Transgenic models indicate the importance of MRAP in adrenal gland formation. Like MC3R and MC4R knockout mice, MRAP2 knockout mice have an obese phenotype. In vitro studies indicate that MRAP2 enhances the MC3 and MC4 response to the agonist αMSH, which, like ACTH, is produced through precursor polypeptide proopiomelanocortin (POMC) cleavage. Analysis of cohorts of individuals with obesity have revealed several MRAP2 genetic variants with loss of function mutations which are causative of monogenic hyperphagic obesity with hyperglycaemia and hypertension. MRAP2 may also be associated with female infertility. This review summarises current knowledge of MRAP and MRAP2, their influence on GPCR signalling, and focusses on pathophysiology, particularly familial glucocorticoid deficiency type-2 and obesity.
Collapse
Affiliation(s)
- Nasrin N A Berruien
- School of Life Sciences, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK.
| | - Caroline L Smith
- School of Life Sciences, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK.
| |
Collapse
|
32
|
Abstract
The prevalence of obesity and the associated comorbidities highlight the importance of understanding the regulation of energy homeostasis. The central melanocortin system plays a critical role in controlling body weight balance. Melanocortin neurons sense and integrate the neuronal and hormonal signals, and then send regulatory projections, releasing anorexigenic or orexigenic melanocortin neuropeptides, to downstream neurons to regulate the food intake and energy expenditure. This review summarizes the latest progress in our understanding of the role of the melanocortin pathway in energy homeostasis. We also review the advances in the identification of human genetic variants that cause obesity via mechanisms that affect the central melanocortin system, which have provided rational targets for treatment of genetically susceptible patients.
Collapse
Affiliation(s)
- Yongjie Yang
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
33
|
Abstract
In the arcuate nucleus (ARC) of the hypothalamus reside two neuronal systems in charge of regulating feeding control and reproductive development. The melanocortin system responds to metabolic fluctuations adjusting food intake, whereas kisspeptin neurons are in charge of the excitatory control of Gonadotropin Hormone Releasing Hormone (GnRH) neurons. While it is known that the melanocortin system regulates GnRH neuronal activity, it was recently demonstrated that kisspeptin neurons not only innervate melanocortin neurons, but also play an active role in the control of metabolism. These two neuronal systems are intricately interconnected forming loops of stimulation and inhibition according to metabolic status. Furthermore, intracellular and epigenetic pathways respond to external environmental signals by changing DNA conformation and gene expression. Here we review the role of Silent mating type Information Regulation 2 homologue 1 (Sirt1), a class III NAD+ dependent protein deacetylase, in the ARC control of pubertal development and feeding behavior.
Collapse
Affiliation(s)
- Carlos F Aylwin
- Division of Neuroscience, Oregon National Primate Research Center, OHSU, Beaverton, OR, USA
| | - Alejandro Lomniczi
- Division of Neuroscience, Oregon National Primate Research Center, OHSU, Beaverton, OR, USA
| |
Collapse
|
34
|
Michael NJ, Watt MJ. Long Chain Fatty Acids Differentially Regulate Sub-populations of Arcuate POMC and NPY Neurons. Neuroscience 2020; 451:164-173. [PMID: 33002557 DOI: 10.1016/j.neuroscience.2020.09.045] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 09/09/2020] [Accepted: 09/21/2020] [Indexed: 02/07/2023]
Abstract
Long chain fatty acids (LCFAs) have been suggested to influence the activity of hypothalamic neurons, however, limited studies have attempted to identify the neurochemical phenotype of these neurons. We aimed to determine if physiological levels of LCFAs alter the electrical excitability of pro-opiomelanocortin (POMC) and neuropeptide Y (NPY) neurons in the arcuate nucleus of the hypothalamus. We utilised whole-cell patch-clamp electrophysiology on brain slice preparations from genetic mouse models where green fluorescent protein was expressed in either POMC or NPY expressing cells. All animals had undergone an overnight fast to replicate conditions in which fatty acids would usually increase. Bath application of LCFAs were found to predominantly inhibit POMC neurons and predominantly excite NPY neurons. Differences between oleic and palmitic acid were not observed. These results suggest that LCFAs in the cerebrospinal fluid exert an underlying orexigenic tone to key hypothalamic neurons known to regulate energy homeostasis.
Collapse
Affiliation(s)
- Natalie J Michael
- Metabolic Disease, Obesity and Diabetes Program, Biomedicine Discovery Institute and the Department of Physiology, Monash University, Clayton 3800, VIC, Australia; Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City G1V4G5, Québec, Canada.
| | - Matthew J Watt
- Department of Physiology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne 3010, VIC, Australia
| |
Collapse
|
35
|
Dunigan AI, Swanson AM, Olson DP, Roseberry AG. Whole-brain efferent and afferent connectivity of mouse ventral tegmental area melanocortin-3 receptor neurons. J Comp Neurol 2020; 529:1157-1183. [PMID: 32856297 DOI: 10.1002/cne.25013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/10/2020] [Accepted: 08/14/2020] [Indexed: 12/27/2022]
Abstract
The mesolimbic dopamine (DA) system is involved in the regulation of multiple behaviors, including feeding, and evidence demonstrates that the melanocortin system can act on the mesolimbic DA system to control feeding and other behaviors. The melanocortin-3 receptor (MC3R) is an important component of the melanocortin system, but its overall role is poorly understood. Because MC3Rs are highly expressed in the ventral tegmental area (VTA) and are likely to be the key interaction point between the melanocortin and mesolimbic DA systems, we set out to identify both the efferent projection patterns of VTA MC3R neurons and the location of the neurons providing afferent input to them. VTA MC3R neurons were broadly connected to neurons across the brain but were strongly connected to a discrete set of brain regions involved in the regulation of feeding, reward, and aversion. Surprisingly, experiments using monosynaptic rabies virus showed that proopiomelanocortin (POMC) and agouti-related protein (AgRP) neurons in the arcuate nucleus made few direct synapses onto VTA MC3R neurons or any of the other major neuronal subtypes in the VTA, despite being extensively labeled by general retrograde tracers injected into the VTA. These results greatly contribute to our understanding of the anatomical interactions between the melanocortin and mesolimbic systems and provide a foundation for future studies of VTA MC3R neurons and the circuits containing them in the control of feeding and other behaviors.
Collapse
Affiliation(s)
- Anna I Dunigan
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Andrew M Swanson
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Aaron G Roseberry
- Department of Biology, Georgia State University, Atlanta, Georgia, USA.,Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| |
Collapse
|
36
|
Flores-Bastías O, Gómez GI, Orellana JA, Karahanian E. Activation of Melanocortin-4 Receptor by a Synthetic Agonist Inhibits Ethanolinduced Neuroinflammation in Rats. Curr Pharm Des 2020; 25:4799-4805. [PMID: 31840601 DOI: 10.2174/1381612825666191216145153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/10/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND High ethanol intake induces a neuroinflammatory response resulting in the subsequent maintenance of chronic alcohol consumption. The melanocortin system plays a pivotal role in the modulation of alcohol consumption. Interestingly, it has been shown that the activation of melanocortin-4 receptor (MC4R) in the brain decreases the neuroinflammatory response in models of brain damage other than alcohol consumption, such as LPS-induced neuroinflammation, cerebral ischemia, glutamate excitotoxicity, and spinal cord injury. OBJECTIVES In this work, we aimed to study whether MC4R activation by a synthetic MC4R-agonist peptide prevents ethanol-induced neuroinflammation, and if alcohol consumption produces changes in MC4R expression in the hippocampus and hypothalamus. METHODS Ethanol-preferring Sprague Dawley rats were selected offering access to 20% ethanol on alternate days for 4 weeks (intermittent access protocol). After this time, animals were i.p. administered an MC4R agonist peptide in the last 2 days of the protocol. Then, the expression of the proinflammatory cytokines interleukin 6 (IL-6), interleukin 1-beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) were measured in the hippocampus, hypothalamus and prefrontal cortex. It was also evaluated if ethanol intake produces alterations in the expression of MC4R in the hippocampus and the hypothalamus. RESULTS Alcohol consumption increased the expression of MC4R in the hippocampus and the hypothalamus. The administration of the MC4R agonist reduced IL-6, IL-1β and TNF-α levels in hippocampus, hypothalamus and prefrontal cortex, to those observed in control rats that did not drink alcohol. CONCLUSION High ethanol consumption produces an increase in the expression of MC4R in the hippocampus and hypothalamus. The administration of a synthetic MC4R-agonist peptide prevents neuroinflammation induced by alcohol consumption in the hippocampus, hypothalamus, and prefrontal cortex. These results could explain the effect of α-MSH and other synthetic MC4R agonists in decreasing alcohol intake through the reduction of the ethanol-induced inflammatory response in the brain.
Collapse
Affiliation(s)
- Osvaldo Flores-Bastías
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile
| | - Gonzalo I Gómez
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile
| | - Juan A Orellana
- Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile.,Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Karahanian
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile
| |
Collapse
|
37
|
Torres AK, Tapia-Rojas C, Cerpa W, Quintanilla RA. Stimulation of Melanocortin Receptor-4 (MC4R) Prevents Mitochondrial Damage Induced by Binge Ethanol Protocol in Adolescent Rat Hippocampus. Neuroscience 2020; 438:70-85. [PMID: 32416118 DOI: 10.1016/j.neuroscience.2020.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 12/28/2022]
Abstract
Binge drinking is a common pattern of adolescent alcohol consumption characterized by a high alcohol intake within a short period of time; which may seriously affect brain function, triggering in some cases an addictive behavior. Current evidence indicates that alcohol addictive conduct is related to the impairment of the Melanocortin System (MCS). This system participates in the regulation of food intake and promotes anti-inflammatory response in the brain. However, the cellular mechanisms involved in the protective effects induced by MCS against binge-alcohol intoxication are still unknown. Here, we studied the effects of MCS activation on mitochondrial and oxidative damage induced by a binge-like protocol in the hippocampus of adolescent rats. We used a pharmacological activator of MC4R (RO27-3225) and evaluated its effects against oxidative injury, mitochondrial failure, and bioenergetics impairment induced by binge ethanol protocol in the hippocampus of adolescent's rats. Our results indicate that MC4R agonist reduces hippocampal oxidative damage promoting antioxidant (Nrf-2) and mitochondrial biogenesis (PGC1-alpha) pathways in animals subjected to the binge-like protocol. Additionally, MC4R activation prevented mitochondrial potential loss and increased mitochondrial mass that were significantly reduced by binge ethanol protocol. Finally, RO27-3225 treatment increased ATP production and mitochondrial respiratory complex expression in adolescent rats exposed to ethanol. Altogether, these findings show that activation of the MCS pathway through MC4R prevents these negative effects of binge ethanol protocol, suggesting a possible role of the MCS in the reduction of the neurotoxic effects induced by alcohol intoxication in adolescents.
Collapse
Affiliation(s)
- Angie K Torres
- Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes (CIAA), Santiago, Chile; Laboratory of Neurodegenerative Diseases, Universidad Autónoma de Chile, Chile; Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Universidad San Sebastián, Chile
| | - Cheril Tapia-Rojas
- Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Universidad San Sebastián, Chile
| | - Waldo Cerpa
- Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes (CIAA), Santiago, Chile; Laboratorio de Función y Patología Neuronal, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8331150 Santiago, Chile
| | - Rodrigo A Quintanilla
- Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes (CIAA), Santiago, Chile; Laboratory of Neurodegenerative Diseases, Universidad Autónoma de Chile, Chile.
| |
Collapse
|
38
|
Chen X, Wyler SC, Li L, Arnold AG, Wan R, Jia L, Landy MA, Lai HC, Xu P, Liu C. Comparative Transcriptomic Analyses of Developing Melanocortin Neurons Reveal New Regulators for the Anorexigenic Neuron Identity. J Neurosci 2020; 40:3165-3177. [PMID: 32213554 PMCID: PMC7159888 DOI: 10.1523/jneurosci.0155-20.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/28/2020] [Accepted: 03/09/2020] [Indexed: 02/07/2023] Open
Abstract
Despite their opposing actions on food intake, POMC and NPY/AgRP neurons in the arcuate nucleus of the hypothalamus (ARH) are derived from the same progenitors that give rise to ARH neurons. However, the mechanism whereby common neuronal precursors subsequently adopt either the anorexigenic (POMC) or the orexigenic (NPY/AgRP) identity remains elusive. We hypothesize that POMC and NPY/AgRP cell fates are specified and maintained by distinct intrinsic factors. In search of them, we profiled the transcriptomes of developing POMC and NPY/AgRP neurons in mice. Moreover, cell-type-specific transcriptomic analyses revealed transcription regulators that are selectively enriched in either population, but whose developmental functions are unknown in these neurons. Among them, we found the expression of the PR domain-containing factor 12 (Prdm12) was enriched in POMC neurons but absent in NPY/AgRP neurons. To study the role of Prdm12 in vivo, we developed and characterized a floxed Prdm12 allele. Selective ablation of Prdm12 in embryonic POMC neurons led to significantly reduced Pomc expression as well as early-onset obesity in mice of either sex that recapitulates symptoms of human POMC deficiency. Interestingly, however, specific deletion of Prdm12 in adult POMC neurons showed that it is no longer required for Pomc expression or energy balance. Collectively, these findings establish a critical role for Prdm12 in the anorexigenic neuron identity and suggest that it acts developmentally to program body weight homeostasis. Finally, the combination of cell-type-specific genomic and genetic analyses provides a means to dissect cellular and functional diversity in the hypothalamus whose neurodevelopment remains poorly studied.SIGNIFICANCE STATEMENT POMC and NPY/AgRP neurons are derived from the same hypothalamic progenitors but have opposing effects on food intake. We profiled the transcriptomes of genetically labeled POMC and NPY/AgRP neurons in the developing mouse hypothalamus to decipher the transcriptional codes behind the versus orexigenic neuron identity. Our analyses revealed 29 transcription regulators that are selectively enriched in one of the two populations. We generated new mouse genetic models to selective ablate one of POMC-neuron enriched transcription factors Prdm12 in developing and adult POMC neurons. Our studies establish a previously unrecognized role for Prdm12 in the anorexigenic neuron identity and suggest that it acts developmentally to program body weight homeostasis.
Collapse
Affiliation(s)
- Xiameng Chen
- Department of Internal Medicine, Hypothalamic Research Center, Dallas, Texas 75390
| | - Steven C Wyler
- Department of Internal Medicine, Hypothalamic Research Center, Dallas, Texas 75390
| | - Li Li
- Department of Internal Medicine, Hypothalamic Research Center, Dallas, Texas 75390
| | - Amanda G Arnold
- Department of Internal Medicine, Hypothalamic Research Center, Dallas, Texas 75390
| | - Rong Wan
- Department of Internal Medicine, Hypothalamic Research Center, Dallas, Texas 75390
| | - Lin Jia
- Department of Internal Medicine, Hypothalamic Research Center, Dallas, Texas 75390
| | - Mark A Landy
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Helen C Lai
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Pin Xu
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Chen Liu
- Department of Internal Medicine, Hypothalamic Research Center, Dallas, Texas 75390
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| |
Collapse
|
39
|
Vázquez-Moreno M, Zeng H, Locia-Morales D, Peralta-Romero J, Asif H, Maharaj A, Tam V, Romero-Figueroa MDS, Sosa-Bustamante GP, Méndez-Martínez S, Mejía-Benítez A, Valladares-Salgado A, Wacher-Rodarte N, Cruz M, Meyre D. The Melanocortin 4 Receptor p.Ile269Asn Mutation Is Associated with Childhood and Adult Obesity in Mexicans. J Clin Endocrinol Metab 2020; 105:5679482. [PMID: 31841602 DOI: 10.1210/clinem/dgz276] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 12/13/2019] [Indexed: 12/19/2022]
Abstract
CONTEXT Rare partial/complete loss-of-function mutations in the melanocortin-4 receptor (MC4R) gene are the most common cause of Mendelian obesity in European populations, but their contribution to obesity in the Mexican population is unclear. OBJECTIVE AND DESIGN We investigated whether deleterious mutations in MC4R contribute to obesity in Mexican children and adults. RESULTS We provide evidence that the MC4R p.Ile269Asn (rs79783591) mutation may have arisen in modern human populations from a founder event in native Mexicans. The MC4R Isoleucine 269 is perfectly conserved across 184 species, which suggests a critical role for the amino acid in MC4R activity. Four in silico tools (SIFT, PolyPhen-2, CADD, MutPred2) predicted a deleterious impact of the p.Ile269Asn substitution on MC4R function. The MC4R p.Ile269Asn mutation was associated with childhood (Ncontrols = 952, Ncases = 661, odds ratio (OR) = 3.06, 95% confidence interval (95%CI) [1.94-4.85]) and adult obesity (Ncontrols = 1445, Ncases = 2,487, OR = 2.58, 95%CI [1.52-4.39]). The frequency of the MC4R p.Ile269Asn mutation ranged from 0.52 to 0.59% and 1.53 to 1.59% in children and adults with normal weight and obesity, respectively. The MC4R p.Ile269Asn mutation co-segregated perfectly with obesity in 5 multigenerational Mexican pedigrees. While adults with obesity carrying the p.Ile269Asn mutation had higher BMI values than noncarriers, this trend was not observed in children. The MC4R p.Ile269Asn mutation accounted for a population attributable risk of 1.28% and 0.68% for childhood and adult obesity, respectively, in the Mexican population. CONCLUSION The MC4R p.Ile269Asn mutation may have emerged as a founder mutation in native Mexicans and is associated with childhood and adult obesity in the modern Mexican population.
Collapse
Affiliation(s)
- Miguel Vázquez-Moreno
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Helen Zeng
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Daniel Locia-Morales
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Jesús Peralta-Romero
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Hamza Asif
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Arjuna Maharaj
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Vivian Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - María D S Romero-Figueroa
- Centro de Investigación en Ciencias de la Salud (CICSA), Facultad de Ciencias de la Salud, Universidad Anáhuac, Campus Norte, Huixquilucan, México
| | | | - Socorro Méndez-Martínez
- Coordinación de Investigación en Salud, Instituto Mexicano del Seguro Social Puebla, Puebla, México
| | - Aurora Mejía-Benítez
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Adan Valladares-Salgado
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Niels Wacher-Rodarte
- Unidad de Investigación en Epidemiología Clínica, Hospital de Especialidades Bernardo Sepúlveda, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | | | - Miguel Cruz
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - David Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
| |
Collapse
|
40
|
Kamermans A, Verhoeven T, van Het Hof B, Koning JJ, Borghuis L, Witte M, van Horssen J, de Vries HE, Rijnsburger M. Setmelanotide, a Novel, Selective Melanocortin Receptor-4 Agonist Exerts Anti-inflammatory Actions in Astrocytes and Promotes an Anti-inflammatory Macrophage Phenotype. Front Immunol 2019; 10:2312. [PMID: 31636637 PMCID: PMC6788433 DOI: 10.3389/fimmu.2019.02312] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/12/2019] [Indexed: 11/13/2022] Open
Abstract
To date, available treatment strategies for multiple sclerosis (MS) are ineffective in preventing or reversing progressive neurologic deterioration, creating a high, and unmet medical need. One potential way to fight MS may be by limiting the detrimental effects of reactive astrocytes, a key pathological hallmark for disease progression. One class of compounds that may exert beneficial effects via astrocytes are melanocortin receptor (MCR) agonists. Among the MCR, MC4R is most abundantly expressed in the CNS and several rodent studies have described that MC4R is—besides neurons—expressed by astrocytes. Activation of MC4R in astrocytes has shown to have potent anti-inflammatory as well as neuroprotective effects in vitro, suggesting that this could be a potential target to ameliorate ongoing inflammation, and neurodegeneration in MS. In this study, we set out to investigate human MC4R expression and analyze its downstream effects. We identified MC4R mRNA and protein to be expressed on astrocytes and observed increased astrocytic MC4R expression in active MS lesions. Furthermore, we show that the novel, highly selective MC4R agonist setmelanotide ameliorates the reactive phenotype in astrocytes in vitro and markedly induced interleukin−6 and −11 production, possibly through enhanced cAMP response element-binding protein (CREB) phosphorylation. Notably, stimulation of human macrophages with medium from astrocytes that were exposed to setmelanotide, skewed macrophages toward an anti-inflammatory phenotype. Taken together, these findings suggest that targeting MC4R on astrocytes might be a novel therapeutic strategy to halt inflammation-associated neurodegeneration in MS.
Collapse
Affiliation(s)
- Alwin Kamermans
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Tom Verhoeven
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Bert van Het Hof
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Jasper J Koning
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Lauri Borghuis
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Maarten Witte
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Jack van Horssen
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Merel Rijnsburger
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
41
|
Szkup M, Owczarek AJ, Schneider-Matyka D, Brodowski J, Łój B, Grochans E. Associations between the components of metabolic syndrome and the polymorphisms in the peroxisome proliferator-activated receptor gamma ( PPAR-γ), the fat mass and obesity-associated ( FTO), and the melanocortin-4 receptor ( MC4R) genes. Aging (Albany NY) 2019; 10:72-82. [PMID: 29315078 PMCID: PMC5811243 DOI: 10.18632/aging.101360] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 12/30/2016] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Metabolic syndrome (MetS) is regarded as a set of abnormalities, increasing the risk of serious functioning disorders. It can develop as a result of genetic predisposition. AIM The aim of this study was to establish associations between MetS-related abnormalities and the PPAR-γ rs1801282, FTO rs9939609, and MC4R rs17782313 polymorphisms. MATERIAL AND METHODS The study involved 425 women aged 45-60 years. The participants were surveyed and subjected to anthropometric, biochemical and genetic analysis. RESULTS In the recessive inheritance model for the FTO polymorphism, a statistically significant relationship was demonstrated between the A/A genotype and glycemia. The results obtained in the codominant and overdominant models for the PPAR-y polymorphism showed a tendency to statistical significance (the C/G genotype inclined to hypertriglyceridemia), and were statistically significant in the codominant, dominant, and recessive models (the C/C genotype predisposed to increased blood pressure). CONCLUSIONS 1. MetS-related abnormalities can be genetically determined, however only some of these relationships can be demonstrated due to the categorical division of symptoms according to the IDF criteria from 2009. 2. The A/A genotype of the FTO rs9939609 polymorphism increases the risk of hyperglycemia, and the C/C genotype of the PPAR-γ rs1801282 variant entails elevated blood pressure in 45-60-year-old women.
Collapse
Affiliation(s)
- Małgorzata Szkup
- Department of Nursing, Pomeranian Medical University in Szczecin, Szczecin, 71-210, Poland
| | - Aleksander Jerzy Owczarek
- Department of Statistics, Department of Instrumental Analysis, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Sosnowiec, 41-200, Poland
| | - Daria Schneider-Matyka
- Department of Nursing, Pomeranian Medical University in Szczecin, Szczecin, 71-210, Poland
| | - Jacek Brodowski
- Primary Care Department, Pomeranian Medical University in Szczecin, Szczecin, 71-210, Poland
| | - Beata Łój
- Klinik für Gynäkologie und Geburtshilfe, Sana HANSE-Klinikum Wismar GmbH, Wismar, 23966, Germany
| | - Elżbieta Grochans
- Department of Nursing, Pomeranian Medical University in Szczecin, Szczecin, 71-210, Poland
| |
Collapse
|
42
|
Moscowitz AE, Asif H, Lindenmaier LB, Calzadilla A, Zhang C, Mirsaeidi M. The Importance of Melanocortin Receptors and Their Agonists in Pulmonary Disease. Front Med (Lausanne) 2019; 6:145. [PMID: 31316990 PMCID: PMC6610340 DOI: 10.3389/fmed.2019.00145] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/10/2019] [Indexed: 12/13/2022] Open
Abstract
Melanocortin agonists are ancient neuropeptides that have steroidogenesis and anti-inflammatory properties. They activate melanocortin receptors (MCR), a family of five seven-transmembrane G-protein coupled receptors. MC1R and MC3R are mainly involved in immunomodulatory effects. Adrenocorticotropin hormone (ACTH) and alpha-Melanocortin stimulating hormone (α-MSH) reduce pro-inflammatory cytokines in several pulmonary inflammatory disorders including asthma, sarcoidosis, and the acute respiratory distress syndrome. They have also been shown to reduce fibrogenesis in animal models with pulmonary fibrosis. By understanding the functions of MCR in macrophages, T-helper cell type 1, and T-helper cell type 17, we may uncover the mechanism of action of melanocortin agonists in sarcoidosis. Further translational and clinical research is needed to define the role of ACTH and α-MSH in pulmonary diseases.
Collapse
Affiliation(s)
| | - Huda Asif
- Division of Pulmonary and Critical Care, University of Miami, Miami, FL, United States
| | | | - Andrew Calzadilla
- Division of Pulmonary and Critical Care, University of Miami, Miami, FL, United States
| | - Chongxu Zhang
- Section of Pulmonary, Miami VA Healthcare System, Miami, FL, United States
| | - Mehdi Mirsaeidi
- Division of Pulmonary and Critical Care, University of Miami, Miami, FL, United States.,Section of Pulmonary, Miami VA Healthcare System, Miami, FL, United States
| |
Collapse
|
43
|
Fetissov SO, Legrand R, Lucas N. Bacterial Protein Mimetic of Peptide Hormone as a New Class of Protein- based Drugs. Curr Med Chem 2019; 26:546-553. [PMID: 28982315 DOI: 10.2174/0929867324666171005110620] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 06/07/2017] [Accepted: 08/27/2017] [Indexed: 01/19/2023]
Abstract
Specific peptide molecules classified as hormones, neuropeptides and cytokines are involved in intercellular signaling regulating various physiological processes in all organs and tissues. This justifies the peptidergic signaling as an attractive pharmacological target. Recently, a protein mimetic of a peptide hormone has been identified in Escherichia coli suggesting the potential use of specific bacterial proteins as a new type of peptide-like drugs. We review the scientific rational and technological approaches leading to the identification of the E. coli caseinolytic protease B (ClpB) homologue protein as a conformational mimetic of α-melanocyte-stimulating hormone (α-MSH), a melanocortin peptide critically involved in the regulation of energy homeostasis in humans and animals. Theoretical and experimental backgrounds for the validation of bacterial ClpB as a potential drug are discussed based on the known E. coli ClpB amino acid sequence homology with α-MSH. Using in silico analysis, we show that other protein sources containing similar to E. coli ClpB α-MSH-like epitopes with potential biological activity may exist in Enterobacteriaceae and in some Brassicaceae. Thus, the original approach leading to the identification of E. coli ClpB as an α-MSH mimetic protein can be applied for the identification of mimetic proteins of other peptide hormones and development of a new type of peptide-like protein-based drugs.
Collapse
Affiliation(s)
- Sergueï O Fetissov
- Inserm UMR1239, 25 rue Lucien Tesniere, 76130, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandy, Rouen, 76000, France
| | | | | |
Collapse
|
44
|
Lotta LA, Mokrosiński J, Mendes de Oliveira E, Li C, Sharp SJ, Luan J, Brouwers B, Ayinampudi V, Bowker N, Kerrison N, Kaimakis V, Hoult D, Stewart ID, Wheeler E, Day FR, Perry JRB, Langenberg C, Wareham NJ, Farooqi IS. Human Gain-of-Function MC4R Variants Show Signaling Bias and Protect against Obesity. Cell 2019; 177:597-607.e9. [PMID: 31002796 PMCID: PMC6476272 DOI: 10.1016/j.cell.2019.03.044] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 02/25/2019] [Accepted: 03/22/2019] [Indexed: 12/13/2022]
Abstract
The melanocortin 4 receptor (MC4R) is a G protein-coupled receptor whose disruption causes obesity. We functionally characterized 61 MC4R variants identified in 0.5 million people from UK Biobank and examined their associations with body mass index (BMI) and obesity-related cardiometabolic diseases. We found that the maximal efficacy of β-arrestin recruitment to MC4R, rather than canonical Gαs-mediated cyclic adenosine-monophosphate production, explained 88% of the variance in the association of MC4R variants with BMI. While most MC4R variants caused loss of function, a subset caused gain of function; these variants were associated with significantly lower BMI and lower odds of obesity, type 2 diabetes, and coronary artery disease. Protective associations were driven by MC4R variants exhibiting signaling bias toward β-arrestin recruitment and increased mitogen-activated protein kinase pathway activation. Harnessing β-arrestin-biased MC4R signaling may represent an effective strategy for weight loss and the treatment of obesity-related cardiometabolic diseases.
Collapse
MESH Headings
- Adult
- Aged
- Body Mass Index
- Coronary Artery Disease/complications
- Coronary Artery Disease/metabolism
- Coronary Artery Disease/pathology
- Cyclic AMP/metabolism
- Databases, Factual
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Female
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Gain of Function Mutation/genetics
- Genetic Predisposition to Disease
- Genotype
- Humans
- Male
- Middle Aged
- Obesity/complications
- Obesity/metabolism
- Obesity/pathology
- Polymorphism, Single Nucleotide
- Receptor, Melanocortin, Type 4/chemistry
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Signal Transduction
- beta-Arrestins/metabolism
Collapse
Affiliation(s)
- Luca A Lotta
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
| | - Jacek Mokrosiński
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Edson Mendes de Oliveira
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Chen Li
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Stephen J Sharp
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Jian'an Luan
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Bas Brouwers
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Vikram Ayinampudi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Nicholas Bowker
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Nicola Kerrison
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Vasileios Kaimakis
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Diana Hoult
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Isobel D Stewart
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Eleanor Wheeler
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Felix R Day
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - John R B Perry
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Claudia Langenberg
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Nicholas J Wareham
- University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - I Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
| |
Collapse
|
45
|
Abstract
The initial discovery that ob/ob mice become obese because of a recessive mutation of the leptin gene has been crucial to discover the melanocortin pathway to control appetite. In the melanocortin pathway, the fed state is signaled by abundance of circulating hormones such as leptin and insulin, which bind to receptors expressed at the surface of pro-opiomelanocortin (POMC) neurons to promote processing of POMC to the mature hormone α-melanocyte-stimulating hormone (α-MSH). The α-MSH released by POMC neurons then signals to decrease energy intake by binding to melanocortin-4 receptor (MC4R) expressed by MC4R neurons to the paraventricular nucleus (PVN). Conversely, in the 'starved state' activity of agouti-related neuropeptide (AgRP) and of neuropeptide Y (NPY)-expressing neurons is increased by decreased levels of circulating leptin and insulin and by the orexigenic hormone ghrelin to promote food intake. This initial understanding of the melanocortin pathway has recently been implemented by the description of the complex neuronal circuit that controls the activity of POMC, AgRP/NPY and MC4R neurons and downstream signaling by these neurons. This review summarizes the progress done on the melanocortin pathway and describes how obesity alters this pathway to disrupt energy homeostasis. We also describe progress on how leptin and insulin receptors signal in POMC neurons, how MC4R signals and how altered expression and traffic of MC4R change the acute signaling and desensitization properties of the receptor. We also describe how the discovery of the melanocortin pathway has led to the use of melanocortin agonists to treat obesity derived from genetic disorders.
Collapse
Affiliation(s)
- Giulia Baldini
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Kevin D. Phelan
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| |
Collapse
|
46
|
Abstract
Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder causing endocrine, musculoskeletal, and neurological dysfunction. PWS is caused by the inactivation of contiguous genes, complicating the development of targeted therapeutics. Clinical trials are now underway in PWS, with more trials to be implemented in the next few years. PWS-like endophenotypes are recapitulated in gene-targeted mice in which the function of one or more PWS genes is disrupted. These animal models can guide priorities for clinical trials or provide information about efficacy of a compound within the context of the specific disease. We now review the current status of preclinical studies that measure the effect of therapeutics on PWS-like endophenotypes. Seven categories of therapeutics (oxytocin and related compounds, K+-ATP channel agonists, melanocortin 4 receptor agonists, incretin mimetics and/or GLP-1 receptor agonists, cannabinoids, ghrelin agents, and Caralluma fimbriata [cactus] extract) have been tested for their effect on endophenotypes in both PWS animal models and clinical trials. Many other therapeutics have been tested in clinical trials, but not preclinical models of PWS or vice versa. Fostering dialogs among investigators performing preclinical validation of animal models and those implementing clinical studies will accelerate the discovery and translation of therapies into clinical practice in PWS.
Collapse
Affiliation(s)
- K Vanessa Carias
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Rachel Wevrick
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
47
|
Spana C, Taylor AW, Yee DG, Makhlina M, Yang W, Dodd J. Probing the Role of Melanocortin Type 1 Receptor Agonists in Diverse Immunological Diseases. Front Pharmacol 2019; 9:1535. [PMID: 30692924 PMCID: PMC6339910 DOI: 10.3389/fphar.2018.01535] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/17/2018] [Indexed: 12/12/2022] Open
Abstract
Background: The melanocortin α-melanocyte stimulating hormone (α-MSH), an endogenous peptide with high affinity for the melanocortin 1 receptor (MC1r), has demonstrated prevention and reversal of intestinal and ocular inflammation in animal models. Preclinical studies were performed to determine whether two MC1r receptor agonists, PL-8177 and PL-8331, exhibit actions and efficacy similar to α-MSH in preventing and reversing intestinal and ocular inflammation. Methods: Both PL-8177 and PL-8331 were assessed in a Eurofins LeadProfilingScreen selectivity panel including 72 in vitro assays. PL-8177 and PL-8331 were evaluated in an in vitro assay using human whole blood stimulated by lipopolysaccharide to determine inhibition of tumor necrosis factor alpha (TNF-α); for comparison, adrenocorticotropic hormone (ACTH) and α-MSH were used as positive controls. PL-8177, dosed at 0.5, 1.5, and 5.0 μg, was assessed in a cannulated rat model of dinitrobenzene sulfonic acid (DNBS)-induced bowel inflammation versus vehicle and oral sulfasalazine. PL-8177 was also dosed at 0.3 mg/kg/mouse injected intraperitoneally versus untreated controls and α-MSH treatment in mice with experimental autoimmune uveitis (EAU). PL-8331 at 3 doses, 3 times daily, was evaluated in a murine model of scopolamine-induced dry eye disease (SiccaSystemTM model), versus twice-daily Restasis® and Xiidra®. Results: Both PL-8177 and PL-8331 demonstrated no significant activity at the 1 μm concentration in any of the 72 in vitro assays. PL-8177 and PL-8331 inhibited lipopolysaccharide-induced TNF-α to a similar degree as ACTH and α-MSH. In the DNBS rat model of bowel inflammation, PL-8177 was significantly superior to untreated controls at all 3 doses (P < 0.05) in reducing bowel inflammation parameters, with effects similar to sulfasalazine. In the murine EAU model, PL-8177 significantly reduced retinal inflammation scores versus untreated controls (P = 0.0001) over 3–5 weeks, and to a similar degree as α-MSH. In the murine scopolamine-induced model of dry eye disease, PL-8331 reduced corneal fluorescein staining scores at all doses, significantly (P = 0.02) for the highest dose (1 × 10-5 mg⋅mL-1), and similarly to Restasis®; Xiidra® demonstrated no effect. Conclusion: The MC1r receptor agonists PL-8177 and PL-8331 exhibited actions similar to those of α-MSH in preventing and reversing intestinal and ocular inflammation in preclinical disease models.
Collapse
Affiliation(s)
- Carl Spana
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | - Andrew W Taylor
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
| | - David G Yee
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
| | | | - Wei Yang
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | - John Dodd
- Palatin Technologies, Inc., Cranbury, NJ, United States
| |
Collapse
|
48
|
Abstract
Adrenocorticotropic hormone (ACTH), and α-, β-, and γ-melanocyte-stimulating hormones (α-, β-, γ-MSH), collectively known as melanocortins, together with their receptors (melanocortin receptors), are components of an ancient modulatory system. The clinical use of ACTH in the treatment of rheumatoid arthritis started in 1949, originally thought that the anti-inflammatory action was through hypothalamus-pituitary-adrenal axis and glucocorticoid-dependent. Subsequent decades have witnessed extensive attempts in unraveling the physiology and pharmacology of the melanocortin system. It is now known that ACTH, together with α-, β-, and γ-MSHs, also possess glucocorticoid-independent anti-inflammatory and immunomodulatory effects by activating the melanocortin receptors expressed in the brain or peripheral immune cells. This review will briefly introduce the melanocortin system and highlight the action of melanocortins in the regulation of immune functions from in vitro, in vivo, preclinical, and clinical studies. The potential therapeutic use of melanocortins are also summarized.
Collapse
Affiliation(s)
- Wei Wang
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Dong-Yu Guo
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
- *Correspondence: Dong-Yu Guo
| | - Yue-Jun Lin
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
- Ya-Xiong Tao
| |
Collapse
|
49
|
Jorgenson E, Matharu N, Palmer MR, Yin J, Shan J, Hoffmann TJ, Thai KK, Zhou X, Hotaling JM, Jarvik GP, Ahituv N, Wessells H, Van Den Eeden SK. Genetic variation in the SIM1 locus is associated with erectile dysfunction. Proc Natl Acad Sci U S A 2018; 115:11018-23. [PMID: 30297428 DOI: 10.1073/pnas.1809872115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Erectile dysfunction is a common condition of men in middle and older ages. Twin studies suggest that about one-third of the risk is due to genetic factors, independent of other known erectile dysfunction risk factors. However, studies that have searched for specific genetic contributors have been limited due to small sample sizes, candidate gene approaches, and weak phenotyping. As a result, there are no confirmed genetic risk factors for erectile dysfunction. This study finds a specific genetic cause for erectile dysfunction. Erectile dysfunction affects millions of men worldwide. Twin studies support the role of genetic risk factors underlying erectile dysfunction, but no specific genetic variants have been identified. We conducted a large-scale genome-wide association study of erectile dysfunction in 36,649 men in the multiethnic Kaiser Permanente Northern California Genetic Epidemiology Research in Adult Health and Aging cohort. We also undertook replication analyses in 222,358 men from the UK Biobank. In the discovery cohort, we identified a single locus (rs17185536-T) on chromosome 6 near the single-minded family basic helix-loop-helix transcription factor 1 (SIM1) gene that was significantly associated with the risk of erectile dysfunction (odds ratio = 1.26, P = 3.4 × 10−25). The association replicated in the UK Biobank sample (odds ratio = 1.25, P = 6.8 × 10−14), and the effect is independent of known erectile dysfunction risk factors, including body mass index (BMI). The risk locus resides on the same topologically associating domain as SIM1 and interacts with the SIM1 promoter, and the rs17185536-T risk allele showed differential enhancer activity. SIM1 is part of the leptin–melanocortin system, which has an established role in body weight homeostasis and sexual function. Because the variants associated with erectile dysfunction are not associated with differences in BMI, our findings suggest a mechanism that is specific to sexual function.
Collapse
|
50
|
Jain S, Panyutin A, Liu N, Xiao C, Piñol RA, Pundir P, Girardet C, Butler AA, Dong X, Gavrilova O, Reitman ML. Melanotan II causes hypothermia in mice by activation of mast cells and stimulation of histamine 1 receptors. Am J Physiol Endocrinol Metab 2018; 315:E357-E366. [PMID: 29812984 PMCID: PMC6171009 DOI: 10.1152/ajpendo.00024.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Intraperitoneal administration of the melanocortin agonist melanotan II (MTII) to mice causes a profound, transient hypometabolism/hypothermia. It is preserved in mice lacking any one of melanocortin receptors 1, 3, 4, or 5, suggesting a mechanism independent of the canonical melanocortin receptors. Here we show that MTII-induced hypothermia was abolished in KitW-sh/W-sh mice, which lack mast cells, demonstrating that mast cells are required. MRGPRB2 is a receptor that detects many cationic molecules and activates mast cells in an antigen-independent manner. In vitro, MTII stimulated mast cells by both MRGPRB2-dependent and -independent mechanisms, and MTII-induced hypothermia was intact in MRGPRB2-null mice. Confirming that MTII activated mast cells, MTII treatment increased plasma histamine levels in both wild-type and MRGPRB2-null, but not in KitW-sh/W-sh, mice. The released histamine produced hypothermia via histamine H1 receptors because either a selective antagonist, pyrilamine, or ablation of H1 receptors greatly diminished the hypothermia. Other drugs, including compound 48/80, a commonly used mast cell activator, also produced hypothermia by both mast cell-dependent and -independent mechanisms. These results suggest that mast cell activation should be considered when investigating the mechanism of drug-induced hypothermia in mice.
Collapse
Affiliation(s)
- Shalini Jain
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH) , Bethesda, Maryland
| | - Anna Panyutin
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH) , Bethesda, Maryland
| | - Naili Liu
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH) , Bethesda, Maryland
| | - Cuiying Xiao
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland
| | - Ramón A Piñol
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland
| | - Priyanka Pundir
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Clémence Girardet
- Department of Pharmacology and Physiology, Saint Louis School of Medicine , St. Louis, Missouri
| | - Andrew A Butler
- Department of Pharmacology and Physiology, Saint Louis School of Medicine , St. Louis, Missouri
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Oksana Gavrilova
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH) , Bethesda, Maryland
| | - Marc L Reitman
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland
| |
Collapse
|