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Thapa K, Ghimire B, Pokharel K, Cai M, Savontaus E, Rinne P. Hepatocyte-specific loss of melanocortin 1 receptor disturbs fatty acid metabolism and promotes adipocyte hypertrophy. Int J Obes (Lond) 2024:10.1038/s41366-024-01600-9. [PMID: 39117851 DOI: 10.1038/s41366-024-01600-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 07/17/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024]
Abstract
BACKGROUND/OBJECTIVES Melanocortins mediate their biological functions via five different melanocortin receptors (MC1R - MC5R). MC1R is expressed in the skin and leukocytes, where it regulates skin pigmentation and inflammatory responses. MC1R is also present in the liver and white adipose tissue, but its functional role in these tissues is unclear. This study aimed at determining the regulatory role of MC1R in fatty acid metabolism. METHODS Male recessive yellow (Mc1re/e) mice, a model of global MC1R deficiency, and male hepatocyte-specific MC1R deficient mice (Mc1r LKO) were fed a chow or Western diet for 12 weeks. The mouse models were characterized for body weight and composition, liver adiposity, adipose tissue mass and morphology, glucose metabolism and lipid metabolism. Furthermore, qPCR and RNA sequencing analyses were used to investigate gene expression profiles in the liver and adipose tissue. HepG2 cells and primary mouse hepatocytes were used to study the effects of pharmacological MC1R activation. RESULTS Chow- and Western diet-fed Mc1re/e showed increased liver weight, white adipose tissue mass and plasma triglyceride (TG) concentration compared to wild type mice. This phenotype occurred without significant changes in food intake, body weight, physical activity or glucose metabolism. Mc1r LKO mice displayed a similar phenotype characterized by larger fat depots, increased adipocyte hypertrophy and enhanced accumulation of TG in the liver and plasma. In terms of gene expression, markers of de novo lipogenesis, inflammation and apoptosis were upregulated in the liver of Mc1r LKO mice, while enzymes regulating lipolysis were downregulated in white adipose tissue of these mice. In cultured hepatocytes, selective activation of MC1R reduced ChREBP expression, which is a central transcription factor for lipogenesis. CONCLUSIONS Hepatocyte-specific loss of MC1R disturbs fatty acid metabolism in the liver and leads to an obesity phenotype characterized by enhanced adipocyte hypertrophy and TG accumulation in the liver and circulation.
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Affiliation(s)
- Keshav Thapa
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
- Drug Research Doctoral Programme (DRDP), University of Turku, Turku, Finland
| | - Bishwa Ghimire
- Institute for Molecular Medicine Finland (FIMM), HiLIFE Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Medicity Research Laboratory, University of Turku, Turku, Finland
| | - Kisun Pokharel
- Natural Resources Institute Finland (Luke), Jokioinen, Finland
| | - Minying Cai
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA
| | - Eriika Savontaus
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
- Turku Center for Disease Modeling, University of Turku, Turku, Finland
- Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - Petteri Rinne
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland.
- Turku Center for Disease Modeling, University of Turku, Turku, Finland.
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Purnell JQ, le Roux CW. Hypothalamic control of body fat mass by food intake: The key to understanding why obesity should be treated as a disease. Diabetes Obes Metab 2024; 26 Suppl 2:3-12. [PMID: 38351898 DOI: 10.1111/dom.15478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/06/2024] [Accepted: 01/18/2024] [Indexed: 03/27/2024]
Abstract
BACKGROUND Hypothalamic centres have been recognized to play a central role in body weight regulation for nearly 70 years. AIMS In this review, we will explore the current undersanding of the role the hypothalamus plays in controlling food intake behaviours. MATERIALS AND METHODS Review of relevant literature from PubMed searches and review article citations. RESULTS Beginning with autopsy studies showing destructive hypothalamic lesions in patients manifesting hyperphagia and rapid weight gain, followed by animal lesioning studies pinpointing adjacent hypothalamic sites as the 'satiety' centre and the 'feeding' centre of the brain, the neurocircuitry that governs our body weight is now understood to consist of a complex, interconnected network, including the hypothalamus and extending to cortical sites, reward centres and brainstem. Neurons in these sites receive afferent signals from the gastrointestinal tract and adipose tissue indicating food availability, calorie content, as well as body fat mass. DISCUSSION Integration of these complex signals leads to modulation of the two prime effector systems that defend a body fat mass set point: food intake and energy expenditure. CONCLUSION Understanding the hypothalamic control of food intake forms the foundation for understanding and managing obesity as a chronic disease.
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Affiliation(s)
- Jonathan Q Purnell
- Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA
| | - Carel W le Roux
- School of Medicine, University College Dublin, Dublin, Ireland
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Valle A, Castillo P, García-Rodríguez A, Palou A, Palou M, Picó C. Brain-Derived Neurotrophic Factor as a Potential Mediator of the Beneficial Effects of Myo-Inositol Supplementation during Suckling in the Offspring of Gestational-Calorie-Restricted Rats. Nutrients 2024; 16:980. [PMID: 38613013 PMCID: PMC11013066 DOI: 10.3390/nu16070980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/21/2024] [Accepted: 03/23/2024] [Indexed: 04/14/2024] Open
Abstract
This study aims to investigate the potential mechanisms underlying the protective effects of myo-inositol (MI) supplementation during suckling against the detrimental effects of fetal energy restriction described in animal studies, particularly focusing on the potential connections with BDNF signaling. Oral physiological doses of MI or the vehicle were given daily to the offspring of control (CON) and 25%-calorie-restricted (CR) pregnant rats during suckling. The animals were weaned and then fed a standard diet until 5 months of age, when the diet was switched to a Western diet until 7 months of age. At 25 days and 7 months of age, the plasma BDNF levels and mRNA expression were analyzed in the hypothalamus and three adipose tissue depots. MI supplementation, especially in the context of gestational calorie restriction, promoted BDNF secretion and signaling at a juvenile age and in adulthood, which was more evident in the male offspring of the CR dams than in females. Moreover, the CR animals supplemented with MI exhibited a stimulated anorexigenic signaling pathway in the hypothalamus, along with improved peripheral glucose management and enhanced browning capacity. These findings suggest a novel connection between MI supplementation during suckling, BDNF signaling, and metabolic programming, providing insights into the mechanisms underlying the beneficial effects of MI during lactation.
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Affiliation(s)
- Ana Valle
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Group of Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands, 07122 Palma, Spain
- Health Research Institute of the Balearic Islands (IdISBa), 07010 Palma, Spain
- Artificial Intelligence Research Institute of the Balearic Islands (IAIB), 07122 Palma, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 28029 Madrid, Spain
| | - Pedro Castillo
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Group of Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands, 07122 Palma, Spain
- Health Research Institute of the Balearic Islands (IdISBa), 07010 Palma, Spain
- Artificial Intelligence Research Institute of the Balearic Islands (IAIB), 07122 Palma, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 28029 Madrid, Spain
| | - Adrián García-Rodríguez
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Group of Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands, 07122 Palma, Spain
- Health Research Institute of the Balearic Islands (IdISBa), 07010 Palma, Spain
- Artificial Intelligence Research Institute of the Balearic Islands (IAIB), 07122 Palma, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 28029 Madrid, Spain
| | - Andreu Palou
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Group of Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands, 07122 Palma, Spain
- Health Research Institute of the Balearic Islands (IdISBa), 07010 Palma, Spain
- Artificial Intelligence Research Institute of the Balearic Islands (IAIB), 07122 Palma, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 28029 Madrid, Spain
| | - Mariona Palou
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Group of Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands, 07122 Palma, Spain
- Health Research Institute of the Balearic Islands (IdISBa), 07010 Palma, Spain
- Artificial Intelligence Research Institute of the Balearic Islands (IAIB), 07122 Palma, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 28029 Madrid, Spain
| | - Catalina Picó
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Group of Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands, 07122 Palma, Spain
- Health Research Institute of the Balearic Islands (IdISBa), 07010 Palma, Spain
- Artificial Intelligence Research Institute of the Balearic Islands (IAIB), 07122 Palma, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 28029 Madrid, Spain
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Metzger PJ, Zhang A, Carlson BA, Sun H, Cui Z, Li Y, Jahnke MT, Layton DR, Gupta MB, Liu N, Kostenis E, Gavrilova O, Chen M, Weinstein LS. A human obesity-associated MC4R mutation with defective Gq/11α signaling leads to hyperphagia in mice. J Clin Invest 2024; 134:e165418. [PMID: 38175730 PMCID: PMC10869179 DOI: 10.1172/jci165418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
Melanocortin 4 receptor (MC4R) mutations are the most common cause of human monogenic obesity and are associated with hyperphagia and increased linear growth. While MC4R is known to activate Gsα/cAMP signaling, a substantial proportion of obesity-associated MC4R mutations do not affect MC4R/Gsα signaling. To further explore the role of specific MC4R signaling pathways in the regulation of energy balance, we examined the signaling properties of one such mutant, MC4R (F51L), as well as the metabolic consequences of MC4RF51L mutation in mice. The MC4RF51L mutation produced a specific defect in MC4R/Gq/11α signaling and led to obesity, hyperphagia, and increased linear growth in mice. The ability of a melanocortin agonist to acutely inhibit food intake when delivered to the paraventricular nucleus (PVN) was lost in MC4RF51L mice, as well as in WT mice in which a specific Gq/11α inhibitor was delivered to the PVN; this provided evidence that a Gsα-independent signaling pathway, namely Gq/11α, significantly contributes to the actions of MC4R on food intake and linear growth. These results suggest that a biased MC4R agonist that primarily activates Gq/11α may be a potential agent to treat obesity with limited untoward cardiovascular and other side effects.
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Affiliation(s)
| | | | | | - Hui Sun
- Metabolic Diseases Branch and
| | - Zhenzhong Cui
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, Maryland, USA
| | | | | | | | | | - Naili Liu
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, Maryland, USA
| | - Evi Kostenis
- Molecular, Cellular, and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, Maryland, USA
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Cardinali G, Kovacs D, Mosca S, Bellei B, Flori E, Morrone A, Mileo AM, Maresca V. The αMSH-Dependent PI3K Pathway Supports Energy Metabolism, via Glucose Uptake, in Melanoma Cells. Cells 2023; 12:cells12071099. [PMID: 37048170 PMCID: PMC10093374 DOI: 10.3390/cells12071099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/29/2023] [Accepted: 04/04/2023] [Indexed: 04/14/2023] Open
Abstract
Stimulation of melanocytes and murine melanoma cells with αMSH plus the PI3K inhibitor LY294002 resulted in ROS increase, oxidative DNA damage, and pigment retention. We performed cellular and molecular biology assays (Western blot, FACS, immunofluorescence analysis, scratch assay) on murine and human melanoma cells. Treatment with αMSH plus LY294002 altered cortical actin architecture. Given that cytoskeleton integrity requires energy, we next evaluated ATP levels and we observed a drop in ATP after exposure to αMSH plus LY294002. To evaluate if the αMSH-activated PI3K pathway could modulate energy metabolism, we focused on glucose uptake by analyzing the expression of the Glut-1 glucose translocator. Compared with cells treated with αMSH alone, those exposed to combined treatment showed a reduction of Glut-1 on the plasma membrane. This metabolic alteration was associated with changes in mitochondrial mass. A significant decrease of the cell migratory potential was also observed. We demonstrated that the αMSH-dependent PI3K pathway acts as a regulator of energy metabolism via glucose uptake, influencing the actin cytoskeleton, which is involved in melanosome release and cell motility. Hence, these results could constitute the basis for innovative therapeutical strategies.
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Affiliation(s)
- Giorgia Cardinali
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy
| | - Daniela Kovacs
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy
| | - Sarah Mosca
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy
| | - Barbara Bellei
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy
| | - Enrica Flori
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy
| | - Aldo Morrone
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy
| | - Anna Maria Mileo
- Tumor Immunology and Immunotherapy Unit, Department of Research Advanced Diagnostic and Technological Innovation, Regina Elena National Cancer Institute, IRCCS, 00144 Rome, Italy
| | - Vittoria Maresca
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy
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6
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Cifuentes L, Campos A, Sacoto D, Ghusn W, De la Rosa A, Feris F, McRae A, Bublitz JT, Hurtado MD, Olson J, Acosta A. Cardiovascular Risk and Diseases in Patients With and Without Leptin-Melanocortin Pathway Variants. Mayo Clin Proc 2023; 98:533-540. [PMID: 36549983 PMCID: PMC10079551 DOI: 10.1016/j.mayocp.2022.10.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 10/09/2022] [Accepted: 10/31/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To study differences in cardiovascular risk factors and diseases between patients with and without genetic variants in the leptin-melanocortin pathway. METHODS A cross-sectional study of patients with a history of severe obesity genotyped in June 2019 as participants of the Mayo Clinic Biobank was conducted in March 2022 to assess differences in cardiovascular risk and diseases between carriers of a heterozygous variant in the leptin-melanocortin pathway and noncarriers. Cardiovascular risk factors included hypertension, diabetes, dyslipidemia, and smoking. Cardiovascular disease includes coronary artery disease, peripheral artery disease, and cerebrovascular accidents. Patients with a history of bariatric surgery were excluded. We used logistic regression models to estimate the odds ratio and 95% CI, adjusting for age, body mass index (BMI), and sex. RESULTS Among a total of 168 carriers (8%; 121 [72%] female; mean [SD] age, 65.1 [14.9] years; BMI, 44.0 [7.4] kg/m2) and 2039 noncarriers (92%; 1446 [71%] female; mean [SD] age, 64.9 [14.4] years; BMI, 42.9 [6.6] kg/m2), carriers had higher prevalence odds of hypertension (odds ratio, 3.26; 95% CI, 2.31 to 4.61; P<.001) and reported higher number of cardiovascular risk factors compared with noncarriers (2.4 [1.1] vs 2.0 [1.1]; P<.001). There were no significant differences in the adjusted odds associated with diabetes, dyslipidemia, smoking, or cardiovascular disease. CONCLUSION Despite having similar body weight and BMI, carriers of heterozygous variants in the leptin-melanocortin pathway had higher rates of hypertension than noncarriers. These findings point to an association between hypertension and leptin-melanocortin pathway variants.
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Affiliation(s)
- Lizeth Cifuentes
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Alejandro Campos
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Daniel Sacoto
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Wissam Ghusn
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Alan De la Rosa
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Fauzi Feris
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Alison McRae
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Joshua T Bublitz
- Division of Epidemiology, Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN
| | - Maria D Hurtado
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN; Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Department of Medicine, Mayo Clinic Health System, La Crosse, WI
| | - Janet Olson
- Division of Epidemiology, Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN
| | - Andres Acosta
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN.
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Al-Sayyar A, Hammad MM, Williams MR, Al-Onaizi M, Abubaker J, Alzaid F. Neurotransmitters in Type 2 Diabetes and the Control of Systemic and Central Energy Balance. Metabolites 2023; 13:384. [PMID: 36984824 PMCID: PMC10058084 DOI: 10.3390/metabo13030384] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 03/08/2023] Open
Abstract
Efficient signal transduction is important in maintaining the function of the nervous system across tissues. An intact neurotransmission process can regulate energy balance through proper communication between neurons and peripheral organs. This ensures that the right neural circuits are activated in the brain to modulate cellular energy homeostasis and systemic metabolic function. Alterations in neurotransmitters secretion can lead to imbalances in appetite, glucose metabolism, sleep, and thermogenesis. Dysregulation in dietary intake is also associated with disruption in neurotransmission and can trigger the onset of type 2 diabetes (T2D) and obesity. In this review, we highlight the various roles of neurotransmitters in regulating energy balance at the systemic level and in the central nervous system. We also address the link between neurotransmission imbalance and the development of T2D as well as perspectives across the fields of neuroscience and metabolism research.
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Affiliation(s)
| | | | | | - Mohammed Al-Onaizi
- Dasman Diabetes Institute, Kuwait City 15462, Kuwait
- Department of Anatomy, Faculty of Medicine, Kuwait University, Kuwait City 13110, Kuwait
| | | | - Fawaz Alzaid
- Dasman Diabetes Institute, Kuwait City 15462, Kuwait
- Institut Necker Enfants Malades-INEM, Université Paris Cité, CNRS, INSERM, F-75015 Paris, France
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8
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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] [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.
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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
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9
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LaPierre MP, Lawler K, Godbersen S, Farooqi IS, Stoffel M. MicroRNA-7 regulates melanocortin circuits involved in mammalian energy homeostasis. Nat Commun 2022; 13:5733. [PMID: 36175420 PMCID: PMC9522793 DOI: 10.1038/s41467-022-33367-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 09/14/2022] [Indexed: 11/09/2022] Open
Abstract
MicroRNAs (miRNAs) modulate physiological responses by repressing the expression of gene networks. We found that global deletion of microRNA-7 (miR-7), the most enriched miRNA in the hypothalamus, causes obesity in mice. Targeted deletion of miR-7 in Single-minded homolog 1 (Sim1) neurons, a critical component of the hypothalamic melanocortin pathway, causes hyperphagia, obesity and increased linear growth, mirroring Sim1 and Melanocortin-4 receptor (MC4R) haplo-insufficiency in mice and humans. We identified Snca (α-Synuclein) and Igsf8 (Immunoglobulin Superfamily Member 8) as miR-7 target genes that act in Sim1 neurons to regulate body weight and endocrine axes. In humans, MIR-7-1 is located in the last intron of HNRNPK, whose promoter drives the expression of both genes. Genetic variants at the HNRNPK locus that reduce its expression are associated with increased height and truncal fat mass. These findings demonstrate that miR-7 suppresses gene networks involved in the hypothalamic melanocortin pathway to regulate mammalian energy homeostasis.
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Affiliation(s)
- Mary P LaPierre
- Institute of Molecular Health Sciences, ETH Zürich, 8093, Zürich, Switzerland
| | - Katherine Lawler
- 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
| | - Svenja Godbersen
- Institute of Molecular Health Sciences, ETH Zürich, 8093, Zürich, Switzerland
| | - 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
| | - Markus Stoffel
- Institute of Molecular Health Sciences, ETH Zürich, 8093, Zürich, Switzerland.
- Medical Faculty, University of Zürich, 8091, Zürich, Switzerland.
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10
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Polat SHB, Dariyerli ND. A Physiological Approach to Inflammatory Markers in Obesity. Biomark Med 2022. [DOI: 10.2174/9789815040463122010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Obesity is one of the most critical health problems all over the world; it is
associated with metabolic dysfunction and overnutrition. Changes in the physiological
function of adipose tissue, leading to altered secretion of adipocytokines, inflammatory
mediators release, and chronic low-grade inflammation, are seen in obesity.
Macrophages, neutrophils, CD4+ and CD8+ T cells, B cells, natural killer T (NKT)
cells, eosinophils, mast cells, and adipocytes are involved in the inflammatory response
that occurs during obesity. Various inflammatory markers are released from these cells.
In this chapter, we will mention inflammatory mechanisms and markers of obesity.
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11
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Bacon EK, Donnelly CG, Bellone RR, Finno CJ, Velie BD. Melanocortin‐1 receptor influence in equine opioid sensitivity. EQUINE VET EDUC 2022. [DOI: 10.1111/eve.13661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Elouise K. Bacon
- Equine Genetics and Genomics Group School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia
| | - Callum G. Donnelly
- Department of Population Health and Reproduction School of Veterinary Medicine University of California Davis California USA
| | - Rebecca R. Bellone
- Department of Population Health and Reproduction School of Veterinary Medicine University of California Davis California USA
- Veterinary Genetics Laboratory School of Veterinary Medicine University of California Davis California USA
| | - Carrie J. Finno
- Department of Population Health and Reproduction School of Veterinary Medicine University of California Davis California USA
| | - Brandon D. Velie
- Equine Genetics and Genomics Group School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia
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Goit RK, Taylor AW, Yin Lo AC. The central melanocortin system as a treatment target for obesity and diabetes: A brief overview. Eur J Pharmacol 2022; 924:174956. [DOI: 10.1016/j.ejphar.2022.174956] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 04/01/2022] [Accepted: 04/11/2022] [Indexed: 12/12/2022]
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13
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Yang D, Hou X, Yang G, Li M, Zhang J, Han M, Zhang Y, Liu Y. Effects of the POMC System on Glucose Homeostasis and Potential Therapeutic Targets for Obesity and Diabetes. Diabetes Metab Syndr Obes 2022; 15:2939-2950. [PMID: 36186941 PMCID: PMC9521683 DOI: 10.2147/dmso.s380577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/13/2022] [Indexed: 11/23/2022] Open
Abstract
The hypothalamus is indispensable in energy regulation and glucose homeostasis. Previous studies have shown that pro-opiomelanocortin neurons receive both central neuronal signals, such as α-melanocyte-stimulating hormone, β-endorphin, and adrenocorticotropic hormone, as well as sense peripheral signals such as leptin, insulin, adiponectin, glucagon-like peptide-1, and glucagon-like peptide-2, affecting glucose metabolism through their corresponding receptors and related signaling pathways. Abnormalities in these processes can lead to obesity, type 2 diabetes, and other metabolic diseases. However, the mechanisms by which these signal molecules fulfill their role remain unclear. Consequently, in this review, we explored the mechanisms of these hormones and signals on obesity and diabetes to suggest potential therapeutic targets for obesity-related metabolic diseases. Multi-drug combination therapy for obesity and diabetes is becoming a trend and requires further research to help patients to better control their blood glucose and improve their prognosis.
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Affiliation(s)
- Dan Yang
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Xintong Hou
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Guimei Yang
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Mengnan Li
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Jian Zhang
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Minmin Han
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Yi Zhang
- Department of Pharmacology, Shanxi Medical University, Taiyuan, People’s Republic of China
- Correspondence: Yi Zhang, Department of Pharmacology, Shanxi Medical University, Taiyuan, People’s Republic of China, Email
| | - Yunfeng Liu
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- Yunfeng Liu, Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China, Tel +86 18703416196, Email
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Duquenne M, Folgueira C, Bourouh C, Millet M, Silva A, Clasadonte J, Imbernon M, Fernandois D, Martinez-Corral I, Kusumakshi S, Caron E, Rasika S, Deliglia E, Jouy N, Oishi A, Mazzone M, Trinquet E, Tavernier J, Kim YB, Ory S, Jockers R, Schwaninger M, Boehm U, Nogueiras R, Annicotte JS, Gasman S, Dam J, Prévot V. Leptin brain entry via a tanycytic LepR-EGFR shuttle controls lipid metabolism and pancreas function. Nat Metab 2021; 3:1071-1090. [PMID: 34341568 PMCID: PMC7611554 DOI: 10.1038/s42255-021-00432-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 06/23/2021] [Indexed: 01/14/2023]
Abstract
Metabolic health depends on the brain's ability to control food intake and nutrient use versus storage, processes that require peripheral signals such as the adipocyte-derived hormone, leptin, to cross brain barriers and mobilize regulatory circuits. We have previously shown that hypothalamic tanycytes shuttle leptin into the brain to reach target neurons. Here, using multiple complementary models, we show that tanycytes express functional leptin receptor (LepR), respond to leptin by triggering Ca2+ waves and target protein phosphorylation, and that their transcytotic transport of leptin requires the activation of a LepR-EGFR complex by leptin and EGF sequentially. Selective deletion of LepR in tanycytes blocks leptin entry into the brain, inducing not only increased food intake and lipogenesis but also glucose intolerance through attenuated insulin secretion by pancreatic β-cells, possibly via altered sympathetic nervous tone. Tanycytic LepRb-EGFR-mediated transport of leptin could thus be crucial to the pathophysiology of diabetes in addition to obesity, with therapeutic implications.
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Affiliation(s)
- Manon Duquenne
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Cintia Folgueira
- Universidade de Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Santiago de Compostela, Spain
| | - Cyril Bourouh
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, CNRS, U1283-UMR 8199-EGID, Lille, France
| | - Marion Millet
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Anisia Silva
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jérôme Clasadonte
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Monica Imbernon
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Daniela Fernandois
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Ines Martinez-Corral
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Soumya Kusumakshi
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Emilie Caron
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - S Rasika
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Eleonora Deliglia
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Nathalie Jouy
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
- Flow Cytometry Core Facility, BioImaging Center of Lille, Hospital Campus, UMS2014-US41, Lille, France
| | - Asturo Oishi
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Massimiliano Mazzone
- Laboratory of Tumor Inflammation and Angiogenesis, Center for Cancer Biology, VIB, Department of Oncology, Leuven, Belgium
| | - Eric Trinquet
- Cisbio Bioassays, Parc Technologique Marcel Boiteux, Codolet, France
| | - Jan Tavernier
- VIB-UGent Center for Medical Biotechnology, Gent, Belgium
| | - Young-Bum Kim
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Stéphane Ory
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Ralf Jockers
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Ulrich Boehm
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Ruben Nogueiras
- Universidade de Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Jean-Sébastien Annicotte
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, CNRS, U1283-UMR 8199-EGID, Lille, France
| | - Stéphane Gasman
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Julie Dam
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Vincent Prévot
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France.
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Vázquez-Moreno M, Locia-Morales D, Valladares-Salgado A, Sharma T, Wacher-Rodarte N, Cruz M, Meyre D. Sex/Gender Modifies the Association Between the MC4R p.Ile269Asn Mutation and Type 2 Diabetes in the Mexican Population. J Clin Endocrinol Metab 2021; 106:e112-e117. [PMID: 33045043 DOI: 10.1210/clinem/dgaa726] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/07/2020] [Indexed: 02/05/2023]
Abstract
CONTEXT Studies in mice and humans suggest that melanocortin-4 receptor (MC4R) deficiency affects body weight in a sex-/gender-dependent manner. However, similar evidence for type 2 diabetes (T2D) is scarce. OBJECTIVE AND DESIGN We investigated whether sex/gender modifies the association between the loss-of-function MC4R p.Ile269Asn mutation and T2D in 6929 Mexican adults (3175 T2D cases and 3754 normal glucose tolerance [NGT] controls). The 2003 American Diabetes Association criteria were used to define NGT and T2D. The MC4R p.Ile269Asn mutation was genotyped in all participants using TaqMan technology. RESULTS The MC4R p.Ile269Asn mutation was associated with T2D in 6929 Mexican adults (Ncontrols = 3754, Ncases = 3175, odds ratio [OR] = 2.00, 95% confidence interval [CI], 1.35-2.97; P = 5.7 × 10-4). The MC4R p.Ile269Asn mutation had a frequency of 0.86 and 1.05% in women with NGT and T2D, and 0.78 and 1.32% in men with NGT and T2D, respectively. We identified a significant interaction between the MC4R p.Ile269Asn mutation and sex/gender on T2D risk (P = 0.049). Although a strong association between the mutation and T2D was observed in men (Ncontrols = 2418, Ncases = 1807, OR = 2.63, 95% CI, 1.62-4.28, P = 9.3 × 10-5), results were not significant in women (Ncontrols = 1336, Ncases = 1368, OR = 1.16, 95% CI, 0.60-2.26, P = 0.65). Further adjustment for body mass index in the logistic regression model did not alter the sex-/gender-specific pattern of association (men: OR = 2.22, 95% CI, 1.34-3.67, P = 0.0019; women: OR = 1.02, 95% CI, 0.51-2.02, P = 0.95). CONCLUSION This is the first report of a male-specific association between the MC4R p.Ile269Asn loss-of-function mutation and T2D in the Mexican population.
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Affiliation(s)
- Miguel Vázquez-Moreno
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI. Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - Daniel Locia-Morales
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI. Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Adan Valladares-Salgado
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI. Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Tanmay Sharma
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - Niels Wacher-Rodarte
- Unidad de Investigación en Epidemiología Clínica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI. Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Miguel Cruz
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI. Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - David Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- nserm UMRS 954 N-GERE (Nutrition-Genetics-Environmental Risks), University de Lorraine, Faculty of Medicine, Nancy, France
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16
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de Souza Cordeiro LM, Elsheikh A, Devisetty N, Morgan DA, Ebert SN, Rahmouni K, Chhabra KH. Hypothalamic MC4R regulates glucose homeostasis through adrenaline-mediated control of glucose reabsorption via renal GLUT2 in mice. Diabetologia 2021; 64:181-194. [PMID: 33052459 PMCID: PMC7718429 DOI: 10.1007/s00125-020-05289-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/18/2020] [Indexed: 12/12/2022]
Abstract
AIMS/HYPOTHESIS Melanocortin 4 receptor (MC4R) mutation is the most common cause of known monogenic obesity in humans. Unexpectedly, humans and rodents with MC4R deficiency do not develop hyperglycaemia despite chronic obesity and insulin resistance. To explain the underlying mechanisms for this phenotype, we determined the role of MC4R in glucose homeostasis in the presence and absence of obesity in mice. METHODS We used global and hypothalamus-specific MC4R-deficient mice to investigate the brain regions that contribute to glucose homeostasis via MC4R. We performed oral, intraperitoneal and intravenous glucose tolerance tests in MC4R-deficient mice that were either obese or weight-matched to their littermate controls to define the role of MC4R in glucose regulation independently of changes in body weight. To identify the integrative pathways through which MC4R regulates glucose homeostasis, we measured renal and adrenal sympathetic nerve activity. We also evaluated glucose homeostasis in adrenaline (epinephrine)-deficient mice to investigate the role of adrenaline in mediating the effects of MC4R in glucose homeostasis. We employed a graded [13C6]glucose infusion procedure to quantify renal glucose reabsorption in MC4R-deficient mice. Finally, we measured the levels of renal glucose transporters in hypothalamus-specific MC4R-deficient mice and adrenaline-deficient mice using western blotting to ascertain the molecular mechanisms underlying MC4R control of glucose homeostasis. RESULTS We found that obese and weight-matched MC4R-deficient mice exhibited improved glucose tolerance due to elevated glucosuria, not enhanced beta cell function. Moreover, MC4R deficiency selectively in the paraventricular nucleus of the hypothalamus (PVH) is responsible for reducing the renal threshold for glucose as measured by graded [13C6]glucose infusion technique. The MC4R deficiency suppressed renal sympathetic nerve activity by 50% in addition to decreasing circulating adrenaline and renal GLUT2 levels in mice, which contributed to the elevated glucosuria. We further report that adrenaline-deficient mice recapitulated the increased excretion of glucose in urine observed in the MC4R-deficient mice. Restoration of circulating adrenaline in both the MC4R- and adrenaline-deficient mice reversed their phenotype of improved glucose tolerance and elevated glucosuria, demonstrating the role of adrenaline in mediating the effects of MC4R on glucose reabsorption. CONCLUSIONS/INTERPRETATION These findings define a previously unrecognised function of hypothalamic MC4R in glucose reabsorption mediated by adrenaline and renal GLUT2. Taken together, our findings indicate that elevated glucosuria due to low sympathetic tone explains why MC4R deficiency does not cause hyperglycaemia despite inducing obesity and insulin resistance. Graphical abstract.
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Affiliation(s)
- Leticia Maria de Souza Cordeiro
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Arwa Elsheikh
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Nagavardhini Devisetty
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Donald A Morgan
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Steven N Ebert
- Division of Metabolic and Cardiovascular Sciences, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Kavaljit H Chhabra
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA.
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Optogenetic stimulation of the liver-projecting melanocortinergic pathway promotes hepatic glucose production. Nat Commun 2020; 11:6295. [PMID: 33293550 PMCID: PMC7722761 DOI: 10.1038/s41467-020-20160-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 11/18/2020] [Indexed: 12/18/2022] Open
Abstract
The central melanocortin system plays a fundamental role in the control of feeding and body weight. Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) also regulate overall glucose homeostasis via insulin-dependent and -independent pathways. Here, we report that a subset of ARC POMC neurons innervate the liver via preganglionic parasympathetic acetylcholine (ACh) neurons in the dorsal motor nucleus of the vagus (DMV). Optogenetic stimulation of this liver-projecting melanocortinergic pathway elevates blood glucose levels that is associated with increased expression of hepatic gluconeogenic enzymes in female and male mice. Pharmacological blockade and knockdown of the melanocortin-4 receptor gene in the DMV abolish this stimulation-induced effect. Activation of melanocortin-4 receptors inhibits DMV cholinergic neurons and optogenetic inhibition of liver-projecting parasympathetic cholinergic fibers increases blood glucose levels. This elevated blood glucose is not due to altered pancreatic hormone release. Interestingly, insulin-induced hypoglycemia increases ARC POMC neuron activity. Hence, this liver-projecting melanocortinergic circuit that we identified may play a critical role in the counterregulatory response to hypoglycemia. Hypothalamic melanocortin neurons regulate systemic glucose homeostasis through incompletely understood pathways. Here, the authors show that a subset of pro-opiomelanocortin neurons innervate the liver via preganglionic parasympathetic cholinergic neurons in the dorsal motor nucleus of the vagus and that stimulation of this pathway elevates blood glucose levels
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Rojo D, McCarthy C, Raingo J, Rubinstein M. Mouse models for V103I and I251L gain of function variants of the human MC4R display decreased adiposity but are not protected against a hypercaloric diet. Mol Metab 2020; 42:101077. [PMID: 32916307 PMCID: PMC7559519 DOI: 10.1016/j.molmet.2020.101077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/20/2020] [Accepted: 09/06/2020] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE The melanocortin 4 receptor (MC4R) is a G protein-coupled receptor that plays major roles in the central control of energy balance. Loss-of-function mutations of MC4R constitute the most common monogenic cause of early-onset extreme obesity in humans, whereas gain-of-function mutations appear to be protective. In particular, two relatively frequent alleles carrying the non-synonymous coding mutations V103I or I251L are associated with lower risks of obesity and type-2 diabetes. Although V103I and I251L MC4Rs showed more efficient signalling in transfected cells, their specific effects in live animals remain unexplored. Here, we investigated whether the introduction of V103I and I251L mutations into the mouse MC4R leads to a lean phenotype and provides protection against an obesogenic diet. METHODS Using CRISPR/Cas9, we generated two novel strains of mice carrying single-nucleotide mutations into the mouse Mc4r which are identical to those present in V103I and I251L MCR4 human alleles, and studied their phenotypic outcomes in mice fed with normal chow or a high-fat diet. In particular, we measured body weight progression, food intake and adiposity. In addition, we analysed glucose homeostasis through glucose and insulin tolerance tests. RESULTS We found that homozygous V103I females displayed shorter longitudinal length and decreased abdominal white fat, whereas homozygous I251L females were also shorter and leaner due to decreased weight in all white fat pads examined. Homozygous Mc4rV103I/V103I and Mc4rI251L/I251L mice of both sexes showed improved glucose homeostasis when challenged in a glucose tolerance test, whereas Mc4rI251L/I251L females showed improved responses to insulin. Despite being leaner and metabolically more efficient, V103I and I251L mutants fed with a hypercaloric diet increased their fasting glucose levels and adiposity similar to their wild-type littermates. CONCLUSIONS Our results demonstrate that mice carrying V103I and I251L MC4R mutations displayed gain-of-function phenotypes that were more evident in females. However, hypermorphic MC4R mutants were as susceptible as their control littermates to the obesogenic and diabetogenic effects elicited by a long-term hypercaloric diet, highlighting the importance of healthy feeding habits even under favourable genetic conditions.
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Affiliation(s)
- Daniela Rojo
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina
| | - Clara McCarthy
- Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de La Plata and Comisión de Investigaciones de la Provincia de Buenos Aires, La Plata, Province of Buenos Aires, Argentina
| | - Jesica Raingo
- Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de La Plata and Comisión de Investigaciones de la Provincia de Buenos Aires, La Plata, Province of Buenos Aires, Argentina
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina; Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
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Micioni Di Bonaventura E, Botticelli L, Tomassoni D, Tayebati SK, Micioni Di Bonaventura MV, Cifani C. The Melanocortin System behind the Dysfunctional Eating Behaviors. Nutrients 2020; 12:E3502. [PMID: 33202557 PMCID: PMC7696960 DOI: 10.3390/nu12113502] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/09/2020] [Accepted: 11/11/2020] [Indexed: 12/11/2022] Open
Abstract
The dysfunction of melanocortin signaling has been associated with obesity, given the important role in the regulation of energy homeostasis, food intake, satiety and body weight. In the hypothalamus, the melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) contribute to the stability of these processes, but MC3R and MC4R are also localized in the mesolimbic dopamine system, the region that responds to the reinforcing properties of highly palatable food (HPF) and where these two receptors seem to affect food reward and motivation. Loss of function of the MC4R, resulting from genetic mutations, leads to overeating in humans, but to date, a clear understanding of the underlying mechanisms and behaviors that promote overconsumption of caloric foods remains unknown. Moreover, the MC4R demonstrated to be a crucial modulator of the stress response, factor that is known to be strictly related to binge eating behavior. In this review, we will explore the preclinical and clinical studies, and the controversies regarding the involvement of melanocortin system in altered eating patterns, especially binge eating behavior, food reward and motivation.
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Affiliation(s)
| | - Luca Botticelli
- School of Pharmacy, University of Camerino, 62032 Camerino, Italy; (E.M.D.B.); (L.B.); (S.K.T.); (C.C.)
| | - Daniele Tomassoni
- School of Bioscience and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy;
| | - Seyed Khosrow Tayebati
- School of Pharmacy, University of Camerino, 62032 Camerino, Italy; (E.M.D.B.); (L.B.); (S.K.T.); (C.C.)
| | | | - Carlo Cifani
- School of Pharmacy, University of Camerino, 62032 Camerino, Italy; (E.M.D.B.); (L.B.); (S.K.T.); (C.C.)
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Counter-regulatory responses to Telfairia occidentalis-induced hypoglycaemia. Metabol Open 2020; 8:100065. [PMID: 33235989 PMCID: PMC7670218 DOI: 10.1016/j.metop.2020.100065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/25/2020] [Accepted: 10/29/2020] [Indexed: 12/27/2022] Open
Abstract
Background Telfairia occidentalis (TO) has many biological activities including blood glucose regulation. Thus, it is being used in the treatment of diabetes mellitus. TO has been shown to cause insulin-mediated hypoglycaemia, which leads to post-hypoglycaemic hyperglycaemia. However, the mechanism involved in the post-hypoglycaemic hyperglycaemia is still poorly understood. Objective This research was designed to determine the response of glucoregulatory hormones and enzymes to TO treatment. Methods Thirty-five male Wistar rats were divided into seven oral treatment groups (n = 5/group), which received either of 100 mg/kg or 200 mg/kg TO for 7-, 10- or 14 days. Results The 7-day treatment with TO significantly increased the levels of insulin, glucagon, and glucose-6-phosphatase (G6Pase) activity but decreased the levels of glucose, adrenaline, and glucokinase (GCK) activity. The 10-day treatment with 100 mg/kg TO increased glucose and decreased GCK activity while 200 mg/kg for the same duration increased glucose, insulin, GCK and G6Pase activities but reduced glucagon. The 14-day treatment with 100 mg/kg TO decreased glucose and glucagon but increased cortisol, while 200 mg/kg TO for same duration increased insulin, but reduced glucagon and GCK activity. Conclusion The TO's post-hypoglycaemic hyperglycaemia results from increased glucagon and G6Pase activity, and reduced GCK activity. Moreover, the glucagon response mainly depends on glucose rather than insulin.
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Key Words
- ANOVA, Analysis of Variance
- Avidin-HRP, Avidin-Horseradish Peroxidase
- Counter-regulatory hormones
- EGP, Endogenous glucose production
- ELISA, Enzyme-linked immunosorbent assay
- G6P, Glucose-6-phosphate
- G6PD, Glucose-6-phosphate dehydrogenase
- G6Pase, Glucose-6-phosphatase
- GCK, Glucokinase
- Glucoregulatory enzymes
- Insulin
- LDH, Lactate dehydrogenase
- LSD, Least Significance Difference
- NAD, Nicotinamide adenine dinucleotide
- NIH, National Institutes of Health
- Plasma glucose
- SEM, Standard error of mean
- SPSS, Statistical Package for the Social Sciences
- TO, Telfairia occidentalis
- Telfairia occidentalis
- cAMP, Cyclic adenosine monophosphate
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21
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Adank DN, Lunzer MM, Ericson MD, Koeperich ZM, Wilber SL, Fleming KA, Haskell-Luevano C. Comparative Intracerebroventricular and Intrathecal Administration of a Nanomolar Macrocyclic Melanocortin Receptor Agonist MDE6-5-2c (c[Pro-His-DPhe-Arg-Trp-Dap-Ala-DPro]) Decreases Food Intake in Mice. ACS Chem Neurosci 2020; 11:3051-3063. [PMID: 32822157 PMCID: PMC7605118 DOI: 10.1021/acschemneuro.0c00409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
There is a critical need to find safe therapeutics to treat an increasingly obese population and diseases associated with an imbalance in energy homeostasis. The melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) ligands have long been the focus to help scientists understand energy homeostasis and the regulation of feeding behavior. Herein, we use a nanomolar macrocyclic melanocortin receptor agonist ligand MDE6-5-2c (c[Pro-His-DPhe-Arg-Trp-Dap-Ala-DPro) to examine metabolic and energy hemostasis profiles upon intrathecal (IT) administration directly into the spinal cord as compared to intracerebroventricular (ICV) administration directly into the brain. Overall, central ICV administration of MDE6-5-2c resulted in decreased food intake, in a dose-dependent manner, and decreased respiratory exchange ratio (RER). Comparison of IT versus ICV routes of MDE6-5-2c administration resulted in MDE6-5-2c possessing a longer duration of action on both feeding behavior and RER via IT. The C-peptide, ghrelin, GIP, leptin, IL-6, and resistin plasma hormones and biomarkers were compared using IT versus ICV MDE6-5-2c routes of administration. Plasma resistin levels were decreased upon ICV treatment of MDE6-5-2c, as compared to ICV vehicle control treatment. Intrathecal treatment resulted in significantly decreased inflammatory cytokine interleukin-6 (IL-6) levels compared to ICV administration. Investigation of the nonselective MC3R and MC4R macrocyclic agonist MDE6-5-2c molecule revealed differences in food intake, RER, and plasma biomarker profiles based upon ICV or IT routes of administration and characterize this novel molecular chemotype as a molecular probe to study the melanocortin system in vivo.
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Affiliation(s)
- Danielle N. Adank
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Mary M. Lunzer
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Mark D. Ericson
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Zoe M. Koeperich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Stacey L. Wilber
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Katlyn A. Fleming
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
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22
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Holland J, Sorrell J, Yates E, Smith K, Arbabi S, Arnold M, Rivir M, Morano R, Chen J, Zhang X, Dimarchi R, Woods SC, Sanchez-Gurmaches J, Wohleb E, Perez-Tilve D. A Brain-Melanocortin-Vagus Axis Mediates Adipose Tissue Expansion Independently of Energy Intake. Cell Rep 2020; 27:2399-2410.e6. [PMID: 31116984 PMCID: PMC6550338 DOI: 10.1016/j.celrep.2019.04.089] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/18/2019] [Accepted: 04/18/2019] [Indexed: 02/07/2023] Open
Abstract
The melanocortin system is a brain circuit that influences energy balance by regulating energy intake and expenditure. In addition, the brain-melanocortin system controls adipose tissue metabolism to optimize fuel mobilization and storage. Specifically, increased brain-melanocortin signaling or negative energy balance promotes lipid mobilization by increasing sympathetic nervous system input to adipose tissue. In contrast, calorie-independent mechanisms favoring energy storage are less understood. Here, we demonstrate that reduction of brain-melanocortin signaling actively promotes fat mass gain by activating the lipogenic program and adipocyte and endothelial cell proliferation in white fat depots independently of caloric intake via efferent nerve fibers conveyed by the common hepatic branch of the vagus nerve. Those vagally regulated obesogenic signals also contribute to the fat mass gain following chronic high-fat diet feeding. These data reveal a physiological mechanism whereby the brain controls energy stores that may contribute to increased susceptibility to obesity. Brain-melanocortin signaling controls fat mass indirectly by regulating energy balance and by direct control of lipid mobilization from adipose tissue via sympathetic nervous system activity. Holland et al. show that reduced brain-melanocortin signaling promotes white adipose tissue expansion via signals conveyed by efferent innervation of the vagus nerve.
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Affiliation(s)
- Jenna Holland
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joyce Sorrell
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Emily Yates
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Kathleen Smith
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Shahriar Arbabi
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Myrtha Arnold
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
| | - Marita Rivir
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Rachel Morano
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jenny Chen
- Genomics, Epigenomics and Sequencing Core, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Xiang Zhang
- Genomics, Epigenomics and Sequencing Core, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Richard Dimarchi
- Novo Nordisk Research Center Indianapolis, IN, USA; Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - Stephen C Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joan Sanchez-Gurmaches
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Division of Endocrinology and Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH, USA
| | - Eric Wohleb
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Diego Perez-Tilve
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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23
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Abstract
Through diverse mechanisms, obesity contributes to worsened cardiometabolic health and increases rates of cardiovascular events. Effective treatment of obesity is necessary to reduce the associated burdens of diabetes mellitus, cardiovascular disease, and death. Despite increasing cardiovascular outcome data on obesity interventions, only a small fraction of the population with obesity are optimally treated. This is a primary impetus for this article in which we describe the typical weight loss, as well as the associated impact on both traditional and novel cardiovascular disease risk factors, provided by the 4 primary modalities for obtaining weight loss in obesity-dietary modification, increasing physical activity, pharmacotherapy, and surgery. We also attempt to highlight instances where changes in metabolic risk are relatively specific to particular interventions and appear at least somewhat independent of weight loss. Finally, we suggest important areas for further research to reduce and prevent adverse cardiovascular consequences due to obesity.
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Affiliation(s)
- Sean P. Heffron
- Leon H. Charney Division of Cardiology, NYU Grossman School of Medicine, New York, NY,NYU Center for the Prevention of Cardiovascular Disease, NYU Grossman School of Medicine, New York, NY,Corresponding author: Sean P. Heffron, 227 East 30 St., #834, New York, NY 10016, 646-501-2735 ,
| | - Johnathon S. Parham
- NYU Center for the Prevention of Cardiovascular Disease, NYU Grossman School of Medicine, New York, NY
| | - Jay Pendse
- Department of Medicine, Division of Endocrinology, NYU Grossman School of Medicine, New York, NY,Medical Service, Veterans Affairs New York Harbor Healthcare System, New York, NY
| | - José O. Alemán
- Department of Medicine, Division of Endocrinology, NYU Grossman School of Medicine, New York, NY
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24
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Georgescu T, Lyons D, Doslikova B, Garcia AP, Marston O, Burke LK, Chianese R, Lam BYH, Yeo GSH, Rochford JJ, Garfield AS, Heisler LK. Neurochemical Characterization of Brainstem Pro-Opiomelanocortin Cells. Endocrinology 2020; 161:bqaa032. [PMID: 32166324 PMCID: PMC7102873 DOI: 10.1210/endocr/bqaa032] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 03/10/2020] [Indexed: 02/08/2023]
Abstract
Genetic research has revealed pro-opiomelanocortin (POMC) to be a fundamental regulator of energy balance and body weight in mammals. Within the brain, POMC is primarily expressed in the arcuate nucleus of the hypothalamus (ARC), while a smaller population exists in the brainstem nucleus of the solitary tract (POMCNTS). We performed a neurochemical characterization of this understudied population of POMC cells using transgenic mice expressing green fluorescent protein (eGFP) under the control of a POMC promoter/enhancer (PomceGFP). Expression of endogenous Pomc mRNA in the nucleus of the solitary tract (NTS) PomceGFP cells was confirmed using fluorescence-activating cell sorting (FACS) followed by quantitative PCR. In situ hybridization histochemistry of endogenous Pomc mRNA and immunohistochemical analysis of eGFP revealed that POMC is primarily localized within the caudal NTS. Neurochemical analysis indicated that POMCNTS is not co-expressed with tyrosine hydroxylase (TH), glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), brain-derived neurotrophic factor (BDNF), nesfatin, nitric oxide synthase 1 (nNOS), seipin, or choline acetyltransferase (ChAT) cells, whereas 100% of POMCNTS is co-expressed with transcription factor paired-like homeobox2b (Phox2b). We observed that 20% of POMCNTS cells express receptors for adipocyte hormone leptin (LepRbs) using a PomceGFP:LepRbCre:tdTOM double-reporter line. Elevations in endogenous or exogenous leptin levels increased the in vivo activity (c-FOS) of a small subset of POMCNTS cells. Using ex vivo slice electrophysiology, we observed that this effect of leptin on POMCNTS cell activity is postsynaptic. These findings reveal that a subset of POMCNTS cells are responsive to both changes in energy status and the adipocyte hormone leptin, findings of relevance to the neurobiology of obesity.
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Affiliation(s)
- Teodora Georgescu
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, UK
- Department of Pharmacology, University of Cambridge, Cambridge, UK
- Centre for Neuroendocrinology & Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - David Lyons
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, UK
| | | | - Ana Paula Garcia
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Oliver Marston
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Luke K Burke
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | | | - Brian Y H Lam
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
| | - Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
| | | | | | - Lora K Heisler
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, UK
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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25
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Sarvestani FS, Zare MA, Saki F, Koohpeyma F, Al-Abdullah IH, Azarpira N. The effect of human wharton's jelly-derived mesenchymal stem cells on MC4R, NPY, and LEPR gene expression levels in rats with streptozotocin-induced diabetes. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2020; 23:214-223. [PMID: 32405365 PMCID: PMC7211357 DOI: 10.22038/ijbms.2019.39582.9387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 08/03/2019] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Type 1 diabetes (T1D) is an autoimmune disease resulting from inflammatory destruction of islets β-cells. Nowadays, progress in cell therapy, especially mesenchymal stem cells (MSCs) proposes numerous potential remedies for T1D. We aimed to investigate the combination therapeutic effect of these cells with insulin and metformin on neuropeptide Y, melanocortin-4 receptor, and leptin receptor genes expression in TID. MATERIALS AND METHODS One hundreds male rats were randomly divided into seven groups: the control, diabetes, insulin (Ins.), insulin+metformin (Ins.Met.), Wharton's Jelly-derived MSCs (WJ-MSCs), insulin+metformin+WJ-MSCs (Ins.Met.MSCs), and insulin+WJ-MSCs (Ins.MSCs). Treatment was performed from the first day after diagnosis as diabetes. Groups of the recipient WJ-MSCs were intraportally injected with 2× 10⁶ MSCs/kg at the 7th and 28th days of study. Fasting blood sugar was monitored and tissues and genes analysis were performed. RESULTS The blood glucose levels were slightly decreased in all treatment groups within 20th and 45th days compared to the diabetic group. The C-peptide level enhanced in these groups compared to the diabetic group, but this increment in Ins.MSCs group on the 45th days was higher than other groups. The expression level of melanocortin-4 receptor and leptin receptor genes meaningfully up-regulated in the treatment groups, while the expression of neuropeptide Y significantly down-regulated in the treatment group on both times of study. CONCLUSION Our data exhibit that infusion of MSCs and its combination therapy with insulin might ameliorate diabetes signs by changing the amount of leptin and subsequent changes in the expression of neuropeptide Y and melanocortin-4 receptor.
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Affiliation(s)
| | - Mohammad Ali Zare
- Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Forough Saki
- Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farhad Koohpeyma
- Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ismail H Al-Abdullah
- Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, USA
| | - Negar Azarpira
- Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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26
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Stanley S, Moheet A, Seaquist ER. Central Mechanisms of Glucose Sensing and Counterregulation in Defense of Hypoglycemia. Endocr Rev 2019; 40:768-788. [PMID: 30689785 PMCID: PMC6505456 DOI: 10.1210/er.2018-00226] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/17/2019] [Indexed: 12/12/2022]
Abstract
Glucose homeostasis requires an organism to rapidly respond to changes in plasma glucose concentrations. Iatrogenic hypoglycemia as a result of treatment with insulin or sulfonylureas is the most common cause of hypoglycemia in humans and is generally only seen in patients with diabetes who take these medications. The first response to a fall in glucose is the detection of impending hypoglycemia by hypoglycemia-detecting sensors, including glucose-sensing neurons in the hypothalamus and other regions. This detection is then linked to a series of neural and hormonal responses that serve to prevent the fall in blood glucose and restore euglycemia. In this review, we discuss the current state of knowledge about central glucose sensing and how detection of a fall in glucose leads to the stimulation of counterregulatory hormone and behavior responses. We also review how diabetes and recurrent hypoglycemia impact glucose sensing and counterregulation, leading to development of impaired awareness of hypoglycemia in diabetes.
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Affiliation(s)
- Sarah Stanley
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Amir Moheet
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Elizabeth R Seaquist
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
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27
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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: 164] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [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.
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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
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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.
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28
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Chen M, Wilson EA, Cui Z, Sun H, Shrestha YB, Podyma B, Le CH, Naglieri B, Pacak K, Gavrilova O, Weinstein LS. G sα deficiency in the dorsomedial hypothalamus leads to obesity, hyperphagia, and reduced thermogenesis associated with impaired leptin signaling. Mol Metab 2019; 25:142-153. [PMID: 31014927 PMCID: PMC6601467 DOI: 10.1016/j.molmet.2019.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 04/08/2019] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Gsα couples multiple receptors, including the melanocortin 4 receptor (MC4R), to intracellular cAMP generation. Germline inactivating Gsα mutations lead to obesity in humans and mice. Mice with brain-specific Gsα deficiency also develop obesity with reduced energy expenditure and locomotor activity, and impaired adaptive thermogenesis, but the underlying mechanisms remain unclear. METHODS We created mice (DMHGsKO) with Gsα deficiency limited to the dorsomedial hypothalamus (DMH) and examined the effects on energy balance and thermogenesis. RESULTS DMHGsKO mice developed severe, early-onset obesity associated with hyperphagia and reduced energy expenditure and locomotor activity, along with impaired brown adipose tissue thermogenesis. Studies in mice with loss of MC4R in the DMH suggest that defective DMH MC4R/Gsα signaling contributes to abnormal energy balance but not to abnormal locomotor activity or cold-induced thermogenesis. Instead, DMHGsKO mice had impaired leptin signaling along with increased expression of the leptin signaling inhibitor protein tyrosine phosphatase 1B in the DMH, which likely contributes to the observed hyperphagia and reductions in energy expenditure, locomotor activity, and cold-induced thermogenesis. CONCLUSIONS DMH Gsα signaling is critical for energy balance, thermogenesis, and leptin signaling. This study provides insight into how distinct signaling pathways can interact to regulate energy homeostasis and temperature regulation.
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Affiliation(s)
- Min Chen
- Metabolic Diseases Branch, Bethesda, MD, 20892, USA.
| | | | - Zhenzhong Cui
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Hui Sun
- Metabolic Diseases Branch, Bethesda, MD, 20892, USA
| | | | | | | | | | - Karel Pacak
- Section on Medical Neuroendocrinology, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
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29
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Derkach K, Zakharova I, Zorina I, Bakhtyukov A, Romanova I, Bayunova L, Shpakov A. The evidence of metabolic-improving effect of metformin in Ay/a mice with genetically-induced melanocortin obesity and the contribution of hypothalamic mechanisms to this effect. PLoS One 2019; 14:e0213779. [PMID: 30870482 PMCID: PMC6417728 DOI: 10.1371/journal.pone.0213779] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 02/19/2019] [Indexed: 12/16/2022] Open
Abstract
In diet-induced obesity, metformin (MF) has weight-lowering effect and improves glucose homeostasis and insulin sensitivity. However, there is no information on the efficiency of MF and the mechanisms of its action in melanocortin-type obesity. We studied the effect of the 10-day treatment with MF at the doses of 200, 400 and 600 mg/kg/day on the food intake and the metabolic and hormonal parameters in female C57Bl/6J (genotype Ay/a) agouti-mice with melanocortin-type obesity, and the influence of MF on the hypothalamic signaling in obese animals at the most effective metabolic dose (600 mg/kg/day). MF treatment led to a decrease in food intake, the body and fat weights, the plasma levels of glucose, insulin and leptin, all increased in agouti-mice, to an improvement of the lipid profile and glucose sensitivity, and to a reduced fatty liver degeneration. In the hypothalamus of obese agouti-mice, the leptin and insulin content was reduced and the expression of the genes encoding leptin receptor (LepR), MC3- and MC4-melanocortin receptors and pro-opiomelanocortin (POMC), the precursor of anorexigenic melanocortin peptides, was increased. The activities of AMP-activated kinase (AMPK) and the transcriptional factor STAT3 were increased, while Akt-kinase activity did not change from control C57Bl/6J (a/a) mice. In the hypothalamus of MF-treated agouti-mice (10 days, 600 mg/kg/day), the leptin and insulin content was restored, Akt-kinase activity was increased, and the activities of AMPK and STAT3 were reduced and did not differ from control mice. In the hypothalamus of MF-treated agouti-mice, the Pomc gene expression was six times higher than in control, while the gene expression for orexigenic neuropeptide Y was decreased by 39%. Thus, we first showed that MF treatment leads to an improvement of metabolic parameters and a decrease of hyperleptinemia and hyperinsulinaemia in genetically-induced melanocortin obesity, and the specific changes in the hypothalamic signaling makes a significant contribution to this effect of MF.
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Affiliation(s)
- Kira Derkach
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Irina Zakharova
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Inna Zorina
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Andrey Bakhtyukov
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Irina Romanova
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Liubov Bayunova
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Alexander Shpakov
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
- * E-mail:
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30
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Fasting blood glucose levels in patients with different types of diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 162:277-292. [PMID: 30905457 DOI: 10.1016/bs.pmbts.2019.01.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Normal human physiology is dependent on a tight control of the fasting blood glucose (FBG) levels. The islets of pancreas maintains FBG levels within a narrow range of 4-6mmol/L by secreting various hormones, especially insulin and glucagon. However, the hormone secretions by the islets of pancreas are governed by a collective effort among pancreas-islet axis, brain-islet axis, liver-islet axis, gut-islet axis, and adipocyte/myocyte-islet axis. Furthermore, the damage of pancreas, vascular system, brain, liver, intestine, adipose, muscle, and other organs and tissues might affect FBG levels through insulin resistance or impaired insulin signaling, which is the hallmark of type 2 diabetes. In this study, 320,572 clinical lab test results of FBG levels from healthy individuals and patients with 64 different types of diseases during the past 5 years in our hospital were retrieved and analyzed. Based on the mean (SD), median, and p (-Log10p) values, we found 57/64 diseases including type 2 diabetes, pancreatitis, diabetic nephropathy, and pancreatic cancer had significantly (p<0.05, -Log10p>1.30) increased whereas 6/64 diseases including preeclampsia, Wilms' tumor, and lupus erythematous had significantly decreased FBG levels compared to that of healthy controls. These data indicated that the increased FBG levels might be a general pathophysiological property of diseased tissues or organs and the increased FBG levels might be a consequence but not the cause for either prediabetes or type 2 diabetes.
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31
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Anderson EJP, Ghamari-Langroudi M, Cakir I, Litt MJ, Chen V, Reggiardo RE, Millhauser GL, Cone RD. Late onset obesity in mice with targeted deletion of potassium inward rectifier Kir7.1 from cells expressing the melanocortin-4 receptor. J Neuroendocrinol 2019; 31:e12670. [PMID: 30561082 PMCID: PMC6533113 DOI: 10.1111/jne.12670] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 11/21/2018] [Accepted: 12/11/2018] [Indexed: 01/01/2023]
Abstract
Energy stores in fat tissue are determined in part by the activity of hypothalamic neurones expressing the melanocortin-4 receptor (MC4R). Even a partial reduction in MC4R expression levels in mice, rats or humans produces hyperphagia and morbid obesity. Thus, it is of great interest to understand the molecular basis of neuromodulation by the MC4R. The MC4R is a G protein-coupled receptor that signals efficiently through GαS , and this signalling pathway is essential for normal MC4R function in vivo. However, previous data from hypothalamic slice preparations indicated that activation of the MC4R depolarised neurones via G protein-independent regulation of the ion channel Kir7.1. In the present study, we show that deletion of Kcnj13 (ie, the gene encoding Kir7.1) specifically from MC4R neurones produced resistance to melanocortin peptide-induced depolarisation of MC4R paraventricular nucleus neurones in brain slices, resistance to the sustained anorexic effect of exogenously administered melanocortin peptides, late onset obesity, increased linear growth and glucose intolerance. Some MC4R-mediated phenotypes appeared intact, including Agouti-related peptide-induced stimulation of food intake and MC4R-mediated induction of peptide YY release from intestinal L cells. Thus, a subset of the consequences of MC4R signalling in vivo appears to be dependent on expression of the Kir7.1 channel in MC4R cells.
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Affiliation(s)
- E. J. P. Anderson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - M. Ghamari-Langroudi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - I. Cakir
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - M. J. Litt
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - Valerie Chen
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California
| | - Roman E. Reggiardo
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California
| | - Glenn L. Millhauser
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California
| | - R. D. Cone
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
- Department of Molecular and Integrative Pharmacology, School of Medicine, University of Michigan, Ann Arbor, Michigan
- Correspondence: Roger D. Cone, Life Sciences Institute, 210 Washtenaw Ave., Ann Arbor, MI 48109,
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Bays H, Perdomo C, Nikonova E, Knoth R, Malhotra M. Lorcaserin and metabolic disease: weight-loss dependent and independent effects. Obes Sci Pract 2018; 4:499-505. [PMID: 30574343 PMCID: PMC6298312 DOI: 10.1002/osp4.296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/18/2018] [Accepted: 07/24/2018] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE Weight management pharmacotherapies can improve metabolic diseases through weight-dependent and weight-independent effects. Lorcaserin is a selective 5-hydroxytryptamine 2C receptor agonist. The objective of this analysis is to quantify the relative contribution of weight loss to the treatment effects of lorcaserin 10 mg twice a day on key metabolic parameters. METHODS This retrospective analysis evaluated 6,897 patients with overweight or obesity (with or without diabetes mellitus) across three randomized, placebo-controlled, double-blind, 52-week clinical trials that evaluated lorcaserin 10 mg twice daily (BID; NCT00395135, NCT00603902, and NCT00603291); 509 patients from only one of the studies had type 2 diabetes mellitus. A mediation analysis was applied to help rank the relative contribution of weight loss to metabolic study outcomes. RESULTS According to this mediation analysis, lorcaserin 10 mg BID improved a spectrum of adiposopathic metabolic abnormalities with varying contributions attributable to weight loss. Improvements in waist circumference and blood pressure were almost exclusively attributable to weight loss. Less than 50% of the improvement in glucose parameters (fasting blood glucose and haemoglobin A1c) were attributable to weight loss. CONCLUSIONS Across Phase III clinical trials, lorcaserin 10 mg BID improved multiple cardiometabolic parameters through both weight-loss dependent and independent mechanisms.
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Affiliation(s)
- H. Bays
- Louisville Metabolic and Atherosclerosis Research CenterLouisvilleKYUSA
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Trotta MC, Maisto R, Alessio N, Hermenean A, D'Amico M, Di Filippo C. The Melanocortin MC5R as a New Target for Treatment of High Glucose-Induced Hypertrophy of the Cardiac H9c2 Cells. Front Physiol 2018; 9:1475. [PMID: 30416452 PMCID: PMC6212602 DOI: 10.3389/fphys.2018.01475] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/28/2018] [Indexed: 12/15/2022] Open
Abstract
The study explored the anti-hypertrophic effect of the melanocortin MC5R stimulation in H9c2 cardiac myocytes exposed to high glucose. This has been done by using α-MSH and selective MC5R agonists and assessing the expression of GLUT4 and GLUT1 transporters, miR-133 and urotensin receptor levels as a marker of cardiac hypertrophy. The study shows for the first time an up-regulation of MC5R expression levels in H9c2 cardiomyocytes exposed to high glucose medium (33 mM D-glucose) for 48 h, compared to cells grown in normal glucose medium (5.5 mM D-glucose). Moreover, H9c2 cells exposed to high glucose showed a significant reduction in cell viability (-40%), a significant increase in total protein per cell number (+109%), and an increase of the urotensin receptor expression levels as an evidence of cells hypertrophy. The pharmacological stimulation of MC5R with α-MSH (90 pM)of the high glucose exposed H9c2 cells increased the cell survival (+50,8%) and reduced the total protein per cell number (-28,2%) with respect to high glucose alone, confirming a reduction of the hypertrophic state as per cell area measurement. Similarly, PG-901 (selective agonist, 10-10 M) significantly increased cell viability (+61,0 %) and reduced total protein per cell number (-40,2%), compared to cells exposed to high glucose alone. Interestingly, the MC5R agonist reduced the GLUT1/GLUT4 glucose transporters ratio on the cell membranes exhibited by the hypertrophic H9c2 cells and increased the intracellular PI3K activity, mediated by a decrease of the levels of the miRNA miR-133a. The beneficial effects of MC5R agonism on the cardiac hypertrophy caused by high glucose was also observed also by echocardiographic evaluations of rats made diabetics with streptozotocin (65 mg/kg i.p.). Therefore, the melanocortin MC5R could be a new target for the treatment of high glucose-induced hypertrophy of the cardiac H9c2 cells.
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Affiliation(s)
- Maria Consiglia Trotta
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Rosa Maisto
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Nicola Alessio
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Anca Hermenean
- Institute of Life Sciences, "Vasile Goldis" Western University of Arad, Arad, Romania
| | - Michele D'Amico
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Clara Di Filippo
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
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34
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Pozo M, Claret M. Hypothalamic Control of Systemic Glucose Homeostasis: The Pancreas Connection. Trends Endocrinol Metab 2018; 29:581-594. [PMID: 29866501 DOI: 10.1016/j.tem.2018.05.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/10/2018] [Accepted: 05/12/2018] [Indexed: 12/22/2022]
Abstract
Maintenance of glucose homeostasis is mandatory for organismal survival. It is accomplished by complex and coordinated interplay between glucose detection mechanisms and multiple effector systems. The brain, in particular homeostatic regions such as the hypothalamus, plays a crucial role in orchestrating such a highly integral response. We review here current understanding of how the hypothalamus senses glucose availability and participates in systemic glucose homeostasis. We provide an update of the relevant signaling pathways and neuronal subsets involved, as well as of the mechanisms modulating metabolic processes in peripheral tissues such as liver, skeletal muscle, fat, and especially the pancreas. We also discuss the relevance of these networks in human biology and prevalent metabolic conditions such as diabetes and obesity.
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Affiliation(s)
- Macarena Pozo
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Marc Claret
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Centro de Investigación Biomédica en Red (CIBER) de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain.
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35
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Podyma B, Sun H, Wilson EA, Carlson B, Pritikin E, Gavrilova O, Weinstein LS, Chen M. The stimulatory G protein G sα is required in melanocortin 4 receptor-expressing cells for normal energy balance, thermogenesis, and glucose metabolism. J Biol Chem 2018; 293:10993-11005. [PMID: 29794140 DOI: 10.1074/jbc.ra118.003450] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/21/2018] [Indexed: 01/05/2023] Open
Abstract
Central melanocortin 4 receptors (MC4Rs) stimulate energy expenditure and inhibit food intake. MC4Rs activate the G protein Gsα, but whether Gsα mediates all MC4R actions has not been established. Individuals with Albright hereditary osteodystrophy (AHO), who have heterozygous Gsα-inactivating mutations, only develop obesity when the Gsα mutation is present on the maternal allele because of tissue-specific genomic imprinting. Furthermore, evidence in mice implicates Gsα imprinting within the central nervous system (CNS) in this disorder. In this study, we examined the effects of Gsα in MC4R-expressing cells on metabolic regulation. Mice with homozygous Gsα deficiency in MC4R-expressing cells (MC4RGsKO) developed significant obesity with increased food intake and decreased energy expenditure, along with impaired insulin sensitivity and cold-induced thermogenesis. Moreover, the ability of the MC4R agonist melanotan-II (MTII) to stimulate energy expenditure and to inhibit food intake was impaired in MC4RGsKO mice. MTII failed to stimulate the secretion of the anorexigenic hormone peptide YY (PYY) from enteroendocrine L cells, a physiological response mediated by MC4R-Gsα signaling, even though baseline PYY levels were elevated in these mice. In Gsα heterozygotes, mild obesity and reduced energy expenditure were present only in mice with a Gsα deletion on the maternal allele in MC4R-expressing cells, whereas food intake was unaffected. These results demonstrate that Gsα signaling in MC4R-expressing cells is required for controlling energy balance, thermogenesis, and peripheral glucose metabolism. They further indicate that Gsα imprinting in MC4R-expressing cells contributes to obesity in Gsα knockout mice and probably in individuals with Albright hereditary osteodystrophy as well.
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Affiliation(s)
| | - Hui Sun
- From the Metabolic Diseases Branch and
| | | | | | | | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | | | - Min Chen
- From the Metabolic Diseases Branch and
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36
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Kwon EJ, You YA, Park B, Ha EH, Kim HS, Park H, Kim YJ. Association between the DNA methylations of POMC, MC4R, and HNF4A and metabolic profiles in the blood of children aged 7-9 years. BMC Pediatr 2018; 18:121. [PMID: 29598821 PMCID: PMC5877386 DOI: 10.1186/s12887-018-1104-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 03/27/2018] [Indexed: 02/07/2023] Open
Abstract
Background Proopiomelanocortin (POMC), melanocortin 4 receptor (MC4R), and hepatocyte nuclear factor 4 alpha (HNF4A) are closely associated with weight gain and metabolic traits. In a previous study, we demonstrated associations between the methylations of POMC, MC4R, and HNF4A and metabolic profiles at birth. However, little is known about these associations in obese children. To evaluate the clinical utility of epigenetic biomarkers, we investigated to determine whether an association exists between the methylations of POMC, MC4R, and HNF4A and metabolic profiles in blood of normal weight and overweight and obese children. Methods We selected 79 normal weight children and 41 overweight and obese children aged 7–9 years in the Ewha Birth and Growth Cohort study. POMC methylation levels at exon 3, and MC4R and HNF4A methylation levels in promoter regions were measured by pyrosequencing. Serum glucose, total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol (HDL–c), and insulin levels were analyzed using a biochemical analyzer and an immunoradiometric assay. Partial correlation and multiple regression analysis were used to assess relationships between POMC, MC4R, and HNF4A methylation levels and metabolic profiles. Results Significant correlations were found between POMC methylation and HDL–c levels, and between HNF4A methylation and both TC and HDL–c levels. Interestingly, associations were found between POMC methylation status and HDL–c levels, and between HNF4A methylation status and TC levels independent of body mass index. Conclusions These findings show that POMC, MC4R, and HNF4A methylation status in the blood of children are associated with metabolic profiles. Therefore, we suggest that the DNA methylation status might serve as a potential epigenetic biomarkers of metabolic syndrome.
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Affiliation(s)
- Eun Jin Kwon
- Department of Obstetrics and Gynecology and Ewha Medical Research Institute, Ewha Womans University Medical School, Seoul, 07985, South Korea.,Department of Occupational and Environmental Medicine, Ewha Womans University Medical School, Seoul, 07985, South Korea
| | - Young-Ah You
- Department of Obstetrics and Gynecology and Ewha Medical Research Institute, Ewha Womans University Medical School, Seoul, 07985, South Korea
| | - Bohyun Park
- Department of Preventive Medicine, Ewha Womans University Medical School, Seoul, 07985, South Korea
| | - Eun Hee Ha
- Department of Occupational and Environmental Medicine, Ewha Womans University Medical School, Seoul, 07985, South Korea
| | - Hae Soon Kim
- Department of Pediatrics, Ewha Womans University Medical School, Seoul, 07985, South Korea
| | - Hyesook Park
- Department of Preventive Medicine, Ewha Womans University Medical School, Seoul, 07985, South Korea.
| | - Young Ju Kim
- Department of Obstetrics and Gynecology, Ewha Womans University Medical School, Seoul, 07985, South Korea.
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37
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Liu TT, Liu BW, He ZG, Feng L, Liu SG, Xiang HB. Delineation of the central melanocortin circuitry controlling the kidneys by a virally mediated transsynaptic tracing study in transgenic mouse model. Oncotarget 2018; 7:69256-69266. [PMID: 27626491 PMCID: PMC5342475 DOI: 10.18632/oncotarget.11956] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/02/2016] [Indexed: 11/25/2022] Open
Abstract
To examine if brain neurons involved in the efferent control of the kidneys possess melanocortin-4 receptor (MC4-R) and/or tryptophan hydroxylase (TPH). Retrograde tracing pseudorabies virus (PRV)-614 was injected into the kidneys in adult male MC4R-green fluorescent protein (GFP) transgenic mice. After a survival time of 3-7 days, spinal cord and brain were removed and sectioned, and processed for PRV-614 visualization. The neurochemical phenotype of PRV-614-positive neurons was identified using double or triple immunocytochemical labeling against PRV-614, MC4R, or TPH. Double and triple labeling was quantified using microscopy. The majority of PRV-614 immunopositive neurons which also expressed immunoreactivity for MC4R were located in the ipsilateral intermediolateral cell column (IML) of the thoracic spinal cord, the paraventricular nucleus (PVN) of the hypothalamus, and raphe pallidus (RPa), nucleus raphe magnus (NRM) and ventromedial medulla (VMM) of the brainstem. Triple-labeled MC4R/PRV-614/TPH neurons were concentrated in the PVN, RPa, NRM and VMM. These data strongly suggest that central MC4R and TPH are involved in the efferent neuronal control of the kidneys.
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Affiliation(s)
- Tao Tao Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Bao Wen Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Zhi Gang He
- Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Li Feng
- Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - San Guang Liu
- Department of Hepatobiliary Surgery, The Second Hospital, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Hong Bing Xiang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
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38
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Alsina R, Trotta M, Bumaschny VF. Hypothalamic Proopiomelanocortin Is Necessary for Normal Glucose Homeostasis in Female Mice. Front Endocrinol (Lausanne) 2018; 9:554. [PMID: 30283405 PMCID: PMC6156137 DOI: 10.3389/fendo.2018.00554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/30/2018] [Indexed: 12/25/2022] Open
Abstract
The arcuate nucleus of the hypothalamus is a key regulator of energy balance and glucose homeostasis. In particular, arcuate proopiomelanocortin (POMC) neurons inhibit food intake, stimulate energy expenditure and increase glucose tolerance. The interruption of insulin or glucose signaling in POMC neurons leads to glucose intolerance without changing energy homeostasis. Although it was previously shown that POMC neurons are necessary for normal glucose homeostasis, the participation of POMC neuropeptide, by mechanisms independent of energy balance, remains to be demonstrated. To study the role of POMC in the regulation of glucose homeostasis, we performed glucose and insulin tolerance tests in non-obese mice lacking hypothalamic POMC expression. We found that POMC deficiency leads to glucose intolerance and insulin resistance in female mice before the onset of obesity or hyperphagia. Conversely, POMC deficiency does not impair glucose homeostasis in non-obese male mice. Interestingly, females completely normalize both glucose and insulin tolerance after genetic POMC restoration. Next, to further study sex dimorphism of POMC neurons regarding glucose homeostasis, we measured glucose-elicited changes in C-FOS by performing immunofluorescence in brain slices of POMC-EGFP mice. Remarkably, we found that glucose-induced C-FOS expression in POMC neurons is more than 3-fold higher in female than in male mice. Altogether, our results reveal a key role of arcuate POMC in the regulation of glucose homeostasis in females. Since POMC reactivation completely reverses the diabetogenic phenotype, arcuate POMC could be a potential target for diabetes therapy.
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Affiliation(s)
- Ramiro Alsina
- Universidad de Buenos Aires, CONICET, Instituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO), Grupo de Neurociencia de Sistemas, Buenos Aires, Argentina
| | - Milagros Trotta
- Universidad de Buenos Aires, CONICET, Instituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO), Grupo de Neurociencia de Sistemas, Buenos Aires, Argentina
| | - Viviana Florencia Bumaschny
- Universidad de Buenos Aires, CONICET, Instituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO), Grupo de Neurociencia de Sistemas, Buenos Aires, Argentina
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Ciencias Fisiológicas, Buenos Aires, Argentina
- *Correspondence: Viviana Florencia Bumaschny
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39
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Litt MJ, Okoye GD, Lark D, Cakir I, Moore C, Barber MC, Atkinson J, Fessel J, Moslehi J, Cone RD. Loss of the melanocortin-4 receptor in mice causes dilated cardiomyopathy. eLife 2017; 6:28118. [PMID: 28829041 PMCID: PMC5577919 DOI: 10.7554/elife.28118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/26/2017] [Indexed: 01/04/2023] Open
Abstract
Haploinsufficiency of the melanocortin-4 receptor, the most common monogenetic obesity syndrome in humans, is associated with a reduction in autonomic tone, bradycardia, and incidence of obesity-associated hypertension. Thus, it has been assumed that melanocortin obesity syndrome may be protective with respect to obesity-associated cardiovascular disease. We show here that absence of the melanocortin-4 receptor (MC4R) in mice causes dilated cardiomyopathy, characterized by reduced contractility and increased left ventricular diameter. This cardiomyopathy is independent of obesity as weight matched diet induced obese mice do not display systolic dysfunction. Mc4r cardiomyopathy is characterized by ultrastructural changes in mitochondrial morphology and cardiomyocyte disorganization. Remarkably, testing of myocardial tissue from Mc4r-/- mice exhibited increased ADP stimulated respiratory capacity. However, this increase in respiration correlates with increased reactive oxygen species production - a canonical mediator of tissue damage. Together this study identifies MC4R deletion as a novel and potentially clinically important cause of heart failure.
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Affiliation(s)
- Michael J Litt
- Departments of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - G Donald Okoye
- Division of Cardiology, Vanderbilt University, Nashville, United States.,Cardio-Oncology Program, Department of Medicine, Vanderbilt University, Nashville, United States
| | - Daniel Lark
- Departments of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - Isin Cakir
- Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Christy Moore
- Allergy Pulmonary and Critical Care, Vanderbilt University Department of Medicine, Nashville, United States
| | - Mary C Barber
- Division of Cardiology, Vanderbilt University, Nashville, United States.,Cardio-Oncology Program, Department of Medicine, Vanderbilt University, Nashville, United States
| | - James Atkinson
- Department of Pathology, Vanderbilt University Medical Center, Nashville, United States
| | - Josh Fessel
- Allergy Pulmonary and Critical Care, Vanderbilt University Department of Medicine, Nashville, United States
| | - Javid Moslehi
- Division of Cardiology, Vanderbilt University, Nashville, United States.,Cardio-Oncology Program, Department of Medicine, Vanderbilt University, Nashville, United States
| | - Roger D Cone
- Departments of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States.,Life Sciences Institute, University of Michigan, Ann Arbor, United States.,Department of Molecular and Integrative Physiology, University of Michigan School of Medicine, Ann Arbor, United States
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40
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Functional variants of the melanocortin-4 receptor associated with the Odontoceti and Mysticeti suborders of cetaceans. Sci Rep 2017; 7:5684. [PMID: 28720755 PMCID: PMC5515947 DOI: 10.1038/s41598-017-05962-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 06/06/2017] [Indexed: 11/09/2022] Open
Abstract
Cetaceans, a group of mammals adapted to the aquatic environment that descended from terrestrial artiodactyls, exhibit tremendous interspecific differences in a number of phenotypes, including feeding behavior, such as filter feeding in the Mysticeti vs prey-hunting Odontoceti, and size, with the smallest cetacean, the vaquita, at 1.4 meters and the largest, the blue whale, reaching 33 meters. The Melanocortin-4 receptor (MC4R) regulates food intake, energy balance, and somatic growth in both mammals and teleosts. In this study, we examined allelic variants of the MC4R in cetaceans. We sequenced the MC4R from 20 cetaceans, and pharmacologically characterized 17 of these protein products. Results identified a single variation at amino acid 156 in the MC4R from representative species of major cetacean lineages uniquely associated with the toothed whales or Odontoceti (arginine at 156) and baleen whales or Mysticeti (glutamine at 156). The Q156 receptor variant found in the larger baleen whales was functionally less responsive to its endogenous anorexigenic ligand, α-MSH. Furthermore, the R156 receptor variant showed greater constitutive activity and a higher affinity for ligand. These data suggest that the MC4R may be one gene involved in the evolution of feeding ecology, energy balance, and body size in cetaceans.
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Chhabra KH, Morgan DA, Tooke BP, Adams JM, Rahmouni K, Low MJ. Reduced renal sympathetic nerve activity contributes to elevated glycosuria and improved glucose tolerance in hypothalamus-specific Pomc knockout mice. Mol Metab 2017; 6:1274-1285. [PMID: 29031726 PMCID: PMC5641634 DOI: 10.1016/j.molmet.2017.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/02/2017] [Accepted: 07/10/2017] [Indexed: 11/11/2022] Open
Abstract
Objective Hypothalamic arcuate nucleus-specific pro-opiomelanocortin deficient (ArcPomc−/−) mice exhibit improved glucose tolerance despite massive obesity and insulin resistance. We demonstrated previously that their improved glucose tolerance is due to elevated glycosuria. However, the underlying mechanisms that link glucose reabsorption in the kidney with ArcPomc remain unclear. Given the function of the hypothalamic melanocortin system in controlling sympathetic outflow, we hypothesized that reduced renal sympathetic nerve activity (RSNA) in ArcPomc−/− mice could explain their elevated glycosuria and consequent enhanced glucose tolerance. Methods We measured RSNA by multifiber recording directly from the nerves innervating the kidneys in ArcPomc−/− mice. To further validate the function of RSNA in glucose reabsorption, we denervated the kidneys of WT and diabetic db/db mice before measuring their glucose tolerance and urine glucose levels. Moreover, we performed western blot and immunohistochemistry to determine kidney GLUT2 and SGLT2 levels in either ArcPomc−/− mice or the renal-denervated mice. Results Consistent with our hypothesis, we found that basal RSNA was decreased in ArcPomc−/− mice relative to their wild type (WT) littermates. Remarkably, both WT and db/db mice exhibited elevated glycosuria and improved glucose tolerance after renal denervation. The elevated glycosuria in obese ArcPomc−/−, WT and db/db mice was due to reduced renal GLUT2 levels in the proximal tubules. Overall, we show that renal-denervated WT and diabetic mice recapitulate the phenotype of improved glucose tolerance and elevated glycosuria associated with reduced renal GLUT2 levels observed in obese ArcPomc−/− mice. Conclusion Hence, we conclude that ArcPomc is essential in maintaining basal RSNA and that elevated glycosuria is a possible mechanism to explain improved glucose tolerance after renal denervation in drug resistant hypertensive patients. Hypothalamic POMC is essential in maintaining basal renal sympathetic nerve activity. Renal denervation improves glucose tolerance in wild-type and db/db mice by elevating their glycosuria. Decreased renal GLUT2 is responsible for elevated glycosuria in mice with suppressed renal sympathetic nerve activity.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Donald A Morgan
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Benjamin P Tooke
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Case Western Reserve University, Cleveland, OH, USA
| | - Jessica M Adams
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA.
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42
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Lensing CJ, Adank DN, Wilber SL, Freeman KT, Schnell SM, Speth RC, Zarth AT, Haskell-Luevano C. A Direct in Vivo Comparison of the Melanocortin Monovalent Agonist Ac-His-DPhe-Arg-Trp-NH 2 versus the Bivalent Agonist Ac-His-DPhe-Arg-Trp-PEDG20-His-DPhe-Arg-Trp-NH 2: A Bivalent Advantage. ACS Chem Neurosci 2017; 8:1262-1278. [PMID: 28128928 DOI: 10.1021/acschemneuro.6b00399] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Bivalent ligands targeting putative melanocortin receptor dimers have been developed and characterized in vitro; however, studies of their functional in vivo effects have been limited. The current report compares the effects of homobivalent ligand CJL-1-87, Ac-His-DPhe-Arg-Trp-PEDG20-His-DPhe-Arg-Trp-NH2, to monovalent ligand CJL-1-14, Ac-His-DPhe-Arg-Trp-NH2, on energy homeostasis in mice after central intracerebroventricular (ICV) administration into the lateral ventricle of the brain. Bivalent ligand CJL-1-87 had noteworthy advantages as an antiobesity probe over CJL-1-14 in a fasting-refeeding in vivo paradigm. Treatment with CJL-1-87 significantly decreased food intake compared to CJL-1-14 or saline (50% less intake 2-8 h after treatment). Furthermore, CJL-1-87 treatment decreased the respiratory exchange ratio (RER) without changing the energy expenditure indicating that fats were being burned as the primary fuel source. Additionally, CJL-1-87 treatment significantly lowered body fat mass percentage 6 h after administration (p < 0.05) without changing the lean mass percentage. The bivalent ligand significantly decreased insulin, C-peptide, leptin, GIP, and resistin plasma levels compared to levels after CJL-1-14 or saline treatments. Alternatively, ghrelin plasma levels were significantly increased. Serum stability of CJL-1-87 and CJL-1-14 (T1/2 = 6.0 and 16.8 h, respectively) was sufficient to permit physiological effects. The differences in binding affinity of CJL-1-14 compared to CJL-1-87 are speculated as a possible mechanism for the bivalent ligand's unique effects. We also provide in vitro evidence for the formation of a MC3R-MC4R heterodimer complex, for the first time to our knowledge, that may be an unexploited neuronal molecular target. Regardless of the exact mechanism, the advantageous ability of CJL-1-87 compared to CJL-1-14 to increase in vitro binding affinity, increase the duration of action in spite of decreased serum stability, decrease in vivo food intake, decrease mice's body fat percent, and differentially affect mouse hormone levels demonstrates the distinct characteristics achieved from the current melanocortin agonist bivalent design strategy.
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Affiliation(s)
- Cody J. Lensing
- Department of Medicinal
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Danielle N. Adank
- Department of Medicinal
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Stacey L. Wilber
- Department of Medicinal
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Katie T. Freeman
- Department of Medicinal
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Sathya M. Schnell
- Department of Medicinal
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Robert C. Speth
- College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida 33328-2018, United States
- Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, United States
| | - Adam T. Zarth
- Department of Medicinal
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Masonic Cancer Center, University of Minnesota, 2231 6th Street SE, 2-210 CCRB, Minneapolis, Minnesota 55455, United States
| | - Carrie Haskell-Luevano
- Department of Medicinal
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Ramírez S, Gómez-Valadés AG, Schneeberger M, Varela L, Haddad-Tóvolli R, Altirriba J, Noguera E, Drougard A, Flores-Martínez Á, Imbernón M, Chivite I, Pozo M, Vidal-Itriago A, Garcia A, Cervantes S, Gasa R, Nogueiras R, Gama-Pérez P, Garcia-Roves PM, Cano DA, Knauf C, Servitja JM, Horvath TL, Gomis R, Zorzano A, Claret M. Mitochondrial Dynamics Mediated by Mitofusin 1 Is Required for POMC Neuron Glucose-Sensing and Insulin Release Control. Cell Metab 2017; 25:1390-1399.e6. [PMID: 28591639 DOI: 10.1016/j.cmet.2017.05.010] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 04/03/2017] [Accepted: 05/23/2017] [Indexed: 11/29/2022]
Abstract
Proopiomelanocortin (POMC) neurons are critical sensors of nutrient availability implicated in energy balance and glucose metabolism control. However, the precise mechanisms underlying nutrient sensing in POMC neurons remain incompletely understood. We show that mitochondrial dynamics mediated by Mitofusin 1 (MFN1) in POMC neurons couple nutrient sensing with systemic glucose metabolism. Mice lacking MFN1 in POMC neurons exhibited defective mitochondrial architecture remodeling and attenuated hypothalamic gene expression programs during the fast-to-fed transition. This loss of mitochondrial flexibility in POMC neurons bidirectionally altered glucose sensing, causing abnormal glucose homeostasis due to defective insulin secretion by pancreatic β cells. Fed mice lacking MFN1 in POMC neurons displayed enhanced hypothalamic mitochondrial oxygen flux and reactive oxygen species generation. Central delivery of antioxidants was able to normalize the phenotype. Collectively, our data posit MFN1-mediated mitochondrial dynamics in POMC neurons as an intrinsic nutrient-sensing mechanism and unveil an unrecognized link between this subset of neurons and insulin release.
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Affiliation(s)
- Sara Ramírez
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Alicia G Gómez-Valadés
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Marc Schneeberger
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Luis Varela
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Roberta Haddad-Tóvolli
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Jordi Altirriba
- Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Eduard Noguera
- Institute for Research in Biomedicine (IRB Barcelona), 08028 Barcelona, Spain; Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain
| | - Anne Drougard
- Institute of Research in Digestive Health (IRSD) - INSERM U1220, European Associated Laboratory "NeuroMicrobiota", University Paul Sabatier, 31024 Toulouse, France
| | - Álvaro Flores-Martínez
- Unidad de Gestión Clínica de Endocrinología y Nutrición, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Mónica Imbernón
- Instituto de Investigaciones Sanitarias (IDIS), CIMUS, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706 Santiago de Compostela, Spain
| | - Iñigo Chivite
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Macarena Pozo
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Andrés Vidal-Itriago
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Ainhoa Garcia
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain; Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Sara Cervantes
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Rosa Gasa
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain; Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Ruben Nogueiras
- Instituto de Investigaciones Sanitarias (IDIS), CIMUS, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706 Santiago de Compostela, Spain
| | - Pau Gama-Pérez
- Department of Physiological Sciences, University of Barcelona, 08907 Barcelona, Spain
| | - Pablo M Garcia-Roves
- Department of Physiological Sciences, University of Barcelona, 08907 Barcelona, Spain; Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - David A Cano
- Unidad de Gestión Clínica de Endocrinología y Nutrición, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Claude Knauf
- Institute of Research in Digestive Health (IRSD) - INSERM U1220, European Associated Laboratory "NeuroMicrobiota", University Paul Sabatier, 31024 Toulouse, France
| | - Joan-Marc Servitja
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain; Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Anatomy and Hystology, University of Veterinary Medicine, Budapest 1078, Hungary
| | - Ramon Gomis
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain; Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Department of Endocrinology and Nutrition, Hospital Clínic. School of Medicine, University of Barcelona, 08036 Barcelona, Spain
| | - Antonio Zorzano
- Institute for Research in Biomedicine (IRB Barcelona), 08028 Barcelona, Spain; Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain.
| | - Marc Claret
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain.
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Melanocortin neurons: Multiple routes to regulation of metabolism. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2477-2485. [PMID: 28499988 DOI: 10.1016/j.bbadis.2017.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/31/2017] [Accepted: 05/05/2017] [Indexed: 01/07/2023]
Abstract
The burden of disability, premature death, escalating health care costs and lost economic productivity due to obesity and its associated complications including hypertension, stroke, cardiovascular disease and type 2 diabetes is staggering [1,2]. A better understanding of metabolic homeostatic pathways will provide us with insights into the biological mechanisms of obesity and how to fundamentally address this epidemic [3-6]. In mammals, energy balance is maintained via a homeostatic system involving both peripheral and central melanocortin systems; changes in body weight reflect an unbalance of the energetic state [7-9]. Although the primary cause of obesity is unknown, there is significant effort to understand the role of the central melanocortin pathway in the brain as it has been shown that deficiency of proopiomelanocortin (POMC) [10,11] and melanocortin 4 receptors (MC4R) [12-15] in both rodents and humans results in severe hyperphagia and obesity [16-23]. In this review, we will summarize how the central melanocortin pathway helps regulate body mass and adiposity within a 'healthy' range through the 'nutrient sensing' network [24-28]. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Liu XW, Yin J, Ma QS, Qi CC, Mu JY, Zhang L, Gao LP, Jing YH. Role of Arcuate Nucleus in the Regulation of Feeding Behavior in the Process of Altitude Acclimatization in Rats. High Alt Med Biol 2017; 18:234-241. [PMID: 28486037 DOI: 10.1089/ham.2016.0141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Liu, Xiang-Wen, Jie Yin, Qi-Sheng Ma, Chu-Chu Qi, Ji-Ying Mu, Lang Zhang, Li-Ping Gao, and Yu-Hong Jing. Role of arcuate nucleus in the regulation of feeding behavior in the process of altitude acclimatization in rats. High Alt Med Biol. 18:234-241, 2017.-Highly efficient energy utilization and metabolic homeostasis maintenance rely on neuromodulation. Altitude exposure is known to stimulate neuroendocrine systems to respond to acute hypoxia and adaptive acclimatization. However, limited data on how the adaptive regulation of the arcuate nucleus performs in the process of altitude acclimatization are available. In the present study, male Sprague Dawley rats were transported to Huashixia, Qinghai (with an altitude of 4400 m) from Xian (with an altitude of 300 m) by air; rats were consistently raised in Xian as control. Food uptake and body weight were measured consecutively after being subjected to high-altitude condition. Contents of plasma leptin and ghrelin were analyzed by the Enzyme Linked Immunosorbent Assay (ELISA) Kits. Brain coronal sections were obtained, and neuropeptide Y (NPY), proopiomelanocotin (POMC), and c-fos immunoreactivity in arcuate nucleus were observed. Arcuate nucleus was isolated from the hypothalamus, and the mRNA of NPY and POMC were measured by quantitative real-time polymerase chain reaction. Our results showed both food consumption and body weight decreased in the high plateau compared with rats raised in the low-altitude condition. Plasma leptin increased at the early stage, and ghrelin decreased at a later stage after reaching the high plateau. The peak of c-fos immunoreactivity in the arcuate nucleus was at day 3 after reaching the high plateau. The expression level of NPY increased, and POMC decreased in the arcuate nucleus at day 7 after reaching the high plateau compared with the plain control group. These results indicate that the arcuate nucleus of hypothalamus performs an important function in regulating feeding behavior during altitude acclimatization. Our study suggested that altitude acclimation is regulated by the hypothalamus that received leptin and ghrelin signals to response by its microcircuit, including NPY- and POMC-neurons in the arcuate nucleus.
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Affiliation(s)
- Xiang-Wen Liu
- 1 Institute of Anatomy, Histology, Embryology, and Neuroscience, School of Basic Medical Sciences, Lanzhou University , Lanzhou, P.R. China
| | - Jie Yin
- 1 Institute of Anatomy, Histology, Embryology, and Neuroscience, School of Basic Medical Sciences, Lanzhou University , Lanzhou, P.R. China
| | - Qi-Sheng Ma
- 2 Department of Basic Medicine, Medical College of Qinghai University , Xining, P.R. China
| | - Chu-Chu Qi
- 1 Institute of Anatomy, Histology, Embryology, and Neuroscience, School of Basic Medical Sciences, Lanzhou University , Lanzhou, P.R. China
| | - Ji-Ying Mu
- 1 Institute of Anatomy, Histology, Embryology, and Neuroscience, School of Basic Medical Sciences, Lanzhou University , Lanzhou, P.R. China
| | - Lang Zhang
- 1 Institute of Anatomy, Histology, Embryology, and Neuroscience, School of Basic Medical Sciences, Lanzhou University , Lanzhou, P.R. China
| | - Li-Ping Gao
- 3 Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University , Lanzhou, P.R. China
| | - Yu-Hong Jing
- 1 Institute of Anatomy, Histology, Embryology, and Neuroscience, School of Basic Medical Sciences, Lanzhou University , Lanzhou, P.R. China .,4 Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University , Lanzhou, P.R. China
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Zhou YT, He ZG, Liu TT, Feng MH, Zhang DY, Xiang HB. Neuroanatomical circuitry between kidney and rostral elements of brain: a virally mediated transsynaptic tracing study in mice. ACTA ACUST UNITED AC 2017; 37:63-69. [PMID: 28224417 DOI: 10.1007/s11596-017-1695-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/14/2016] [Indexed: 12/13/2022]
Abstract
The identity of higher-order neurons and circuits playing an associative role to control renal function is not well understood. We identified specific neural populations of rostral elements of brain regions that project multisynaptically to the kidneys in 3-6 days after injecting a retrograde tracer pseudorabies virus (PRV)-614 into kidney of 13 adult male C57BL/6J strain mice. PRV-614 infected neurons were detected in a number of mesencephalic (e.g. central amygdala nucleus), telencephalic regions and motor cortex. These divisions included the preoptic area (POA), dorsomedial hypothalamus (DMH), lateral hypothalamus, arcuate nucleus (Arc), suprachiasmatic nucleus (SCN), periventricular hypothalamus (PeH), and rostral and caudal subdivision of the paraventricular nucleus of the hypothalamus (PVN). PRV-614/Tyrosine hydroxylase (TH) double-labeled cells were found within DMH, Arc, SCN, PeH, PVN, the anterodorsal and medial POA. A subset of neurons in PVN that participated in regulating sympathetic outflow to kidney was catecholaminergic or serotonergic. PRV-614 infected neurons within the PVN also contained arginine vasopressin or oxytocin. These data demonstrate the rostral elements of brain innervate the kidney by the neuroanatomical circuitry.
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Affiliation(s)
- Ye-Ting Zhou
- Department of Surgery, Shuyang Hospital, Shuyang, 223600, China
| | - Zhi-Gang He
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Tao-Tao Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Mao-Hui Feng
- Department of Oncology, Wuhan Peritoneal Cancer Clinical Medical Research Center, Zhangnan Hospital of Wuhan University, Wuhan, 430071, China.
| | - Ding-Yu Zhang
- Intensive Care Unit, Wuhan Medical Treatment Center, Wuhan, 430023, China.
| | - Hong-Bing Xiang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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Severe Atherosclerosis and Hypercholesterolemia in Mice Lacking Both the Melanocortin Type 4 Receptor and Low Density Lipoprotein Receptor. PLoS One 2016; 11:e0167888. [PMID: 28030540 PMCID: PMC5193345 DOI: 10.1371/journal.pone.0167888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 11/22/2016] [Indexed: 11/19/2022] Open
Abstract
Dysfunction of the melanocortin system can result in severe obesity accompanied with dyslipidemia and symptoms of the metabolic syndrome but the effect on vascular atherogenesis is not known. To study the impact of obesity and dyslipidemia on the cardiovascular system, we generated mice double-deficient for the melanocortin type 4 receptor (Mc4rmut mice) and the LDL receptor (Ldlr-/- mice). Mc4rmut mice develop obesity due to hyperphagia. Double-mutant mice (Mc4rmut;Ldlr-/-) exhibited massive increases in body weight, plasma cholesterol and triacylglycerol levels and developed atherosclerosis. Atherosclerotic lesion size was affected throughout the aortic root and brachiocephalic artery not only under semisynthetic, cholesterol-containing diet but also under cholesterol-free standard chow. The Mc4rmut mice developed a hepatic steatosis which contributes to increased plasma cholesterol levels even under cholesterol-free standard chow. Transcripts of cholesterol biosynthesis components and liver cholesterol levels did not significantly differ between wild-type and all mutant mouse strains but RNA sequencing data and biochemical measurements point to an altered bile acid elimination in Mc4rmut;Ldlr-/-. Therefore, the unchanged endogenous cholesterol biosynthesis together with a reduced hepatic VLDL and LDL-cholesterol clearance most likely led to increased plasma lipid levels and consequently to atherosclerosis in this animal model. Our data indicate that dysfunction of the melanocortin-regulated food intake and the resulting obesity significantly add to the proatherogenic lipoprotein profile caused by LDL receptor deficiency and, therefore, can be regarded as relevant risk factor for atherosclerosis.
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Chen M, Shrestha YB, Podyma B, Cui Z, Naglieri B, Sun H, Ho T, Wilson EA, Li YQ, Gavrilova O, Weinstein LS. Gsα deficiency in the dorsomedial hypothalamus underlies obesity associated with Gsα mutations. J Clin Invest 2016; 127:500-510. [PMID: 27991864 DOI: 10.1172/jci88622] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 11/10/2016] [Indexed: 11/17/2022] Open
Abstract
Gsα, encoded by Gnas, mediates hormone and neurotransmitter receptor-stimulated cAMP generation. Heterozygous Gsα-inactivating mutations lead to obesity in Albright hereditary osteodystrophy (AHO) patients, but only when the mutations occur on the maternal allele. This parent-of-origin effect is due to Gsα imprinting in the CNS, although the relevant CNS regions are unknown. We have now shown that mice with a Gnas gene deletion disrupting Gsα expression on the maternal allele, but not the paternal allele, in the dorsomedial nucleus of the hypothalamus (DMH) developed obesity and reduced energy expenditure without hyperphagia. Although maternal Gnas deletion impaired activation of brown adipose tissue (BAT) in mice, their responses to cold environment remained intact. Similar findings were observed in mice with DMH-specific deficiency of melanocortin MC4R receptors, which are known to activate Gsα. Our results show that Gsα imprinting in the DMH underlies the parent-of-origin metabolic phenotype that results from Gsα mutations and that DMH MC4R/Gsα signaling is important for regulation of energy expenditure and BAT activation, but not the metabolic response to cold.
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Ladyman SR, Grattan DR. Central Effects of Leptin on Glucose Homeostasis are Modified during Pregnancy in the Rat. J Neuroendocrinol 2016; 28. [PMID: 27623562 DOI: 10.1111/jne.12431] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 08/03/2016] [Accepted: 09/10/2016] [Indexed: 01/03/2023]
Abstract
Despite increased leptin concentrations during pregnancy, fat mass and food intake are increased. The satiety response to central leptin is suppressed, indicating a state of leptin insensitivity in the hypothalamus. Although the regulation of food intake is a major function of leptin, this hormone also influences a wide range of functions within the body. These actions include the regulation of glucose homeostasis, which undergoes major adaptation in the maternal body to generate optimal conditions for foetal development and growth. The present study aimed to investigate the effects of central leptin treatment on glucose homeostasis in pregnant rats to determine whether pregnancy-induced leptin insensitivity is functionally specific, and to further investigate changes in glucose homeostasis during pregnancy. After an overnight fast, nonpregnant and day 14 pregnant rats received an i.c.v. injection of leptin (100 ng or 4 μg) or vehicle then underwent a glucose tolerance test (GTT). Further groups of nonpregnant and day 14 pregnant rats were killed 30 min after leptin (doses ranging from 40 ng-4 μg) or vehicle i.c.v. injections for western blot analysis of phospho-signal transducer and activator of transcription 3 (STAT3) and phospho-Akt in various hypothalamic nuclei. Central leptin injection prior to a GTT lead to lowered basal insulin concentrations and impaired glucose tolerance in nonpregnant female rats, whereas the same doses of leptin had no significant effect on glucose tolerance in day 14 pregnant rats, indicating that, similar to the satiety actions of leptin, the effects of leptin on glucose homeostasis are suppressed during pregnancy. Furthermore, in the arcuate nucleus and ventromedial and dorsomedial nuclei of the hypothalamus, comprising three leptin-sensitive areas, there was no evidence that leptin induced Akt phosphorylation despite significant increases in phospho-STAT3, suggesting that leptin does not act through phospho-Akt in these areas in female rats.
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Affiliation(s)
- S R Ladyman
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago, Dunedin, New Zealand.
| | - D R Grattan
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago, Dunedin, New Zealand
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50
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Enriori PJ, Chen W, Garcia-Rudaz MC, Grayson BE, Evans AE, Comstock SM, Gebhardt U, Müller HL, Reinehr T, Henry BA, Brown RD, Bruce CR, Simonds SE, Litwak SA, McGee SL, Luquet S, Martinez S, Jastroch M, Tschöp MH, Watt MJ, Clarke IJ, Roth CL, Grove KL, Cowley MA. α-Melanocyte stimulating hormone promotes muscle glucose uptake via melanocortin 5 receptors. Mol Metab 2016; 5:807-822. [PMID: 27688995 PMCID: PMC5034615 DOI: 10.1016/j.molmet.2016.07.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 07/26/2016] [Accepted: 07/28/2016] [Indexed: 01/21/2023] Open
Abstract
Objective Central melanocortin pathways are well-established regulators of energy balance. However, scant data exist about the role of systemic melanocortin peptides. We set out to determine if peripheral α-melanocyte stimulating hormone (α-MSH) plays a role in glucose homeostasis and tested the hypothesis that the pituitary is able to sense a physiological increase in circulating glucose and responds by secreting α-MSH. Methods We established glucose-stimulated α-MSH secretion using humans, non-human primates, and mouse models. Continuous α-MSH infusions were performed during glucose tolerance tests and hyperinsulinemic-euglycemic clamps to evaluate the systemic effect of α-MSH in glucose regulation. Complementary ex vivo and in vitro techniques were employed to delineate the direct action of α-MSH via the melanocortin 5 receptor (MC5R)–PKA axis in skeletal muscles. Combined treatment of non-selective/selective phosphodiesterase inhibitor and α-MSH was adopted to restore glucose tolerance in obese mice. Results Here we demonstrate that pituitary secretion of α-MSH is increased by glucose. Peripheral α-MSH increases temperature in skeletal muscles, acts directly on soleus and gastrocnemius muscles to significantly increase glucose uptake, and enhances whole-body glucose clearance via the activation of muscle MC5R and protein kinase A. These actions are absent in obese mice, accompanied by a blunting of α-MSH-induced cAMP levels in skeletal muscles of obese mice. Both selective and non-selective phosphodiesterase inhibition restores α-MSH induced skeletal muscle glucose uptake and improves glucose disposal in obese mice. Conclusion These data describe a novel endocrine circuit that modulates glucose homeostasis by pituitary α-MSH, which increases muscle glucose uptake and thermogenesis through the activation of a MC5R-PKA-pathway, which is disrupted in obesity. Glucose stimulates α-MSH release from the pituitary. Systemic α-MSH drives glucose disposal and thermogenesis in skeletal muscles. α-MSH acts on MC5R expressed on skeletal muscles and activate cAMP-PKA pathway. The combined treatment of nonselective or selective PDE 4 inhibitor and α-MSH ameliorates glucose intolerance in obese mice.
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Affiliation(s)
- Pablo J Enriori
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Weiyi Chen
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Maria C Garcia-Rudaz
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | | | - Anne E Evans
- Division Neuroscience, Oregon Health and Science University, Oregon, USA
| | - Sarah M Comstock
- Division Neuroscience, Oregon Health and Science University, Oregon, USA
| | - Ursel Gebhardt
- Department of Pediatrics, Vestische Children Hospital Datteln, University of Witten/Herdecke, Germany
| | - Hermann L Müller
- Department of Pediatrics, Vestische Children Hospital Datteln, University of Witten/Herdecke, Germany
| | - Thomas Reinehr
- Department of Pediatrics, Klinikum Oldenburg GmbH, Germany
| | - Belinda A Henry
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Russell D Brown
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Clinton R Bruce
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Stephanie E Simonds
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Sara A Litwak
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Sean L McGee
- Metabolic Research Unit, School of Medicine, Deakin University, Vic, Australia
| | - Serge Luquet
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, F-75205 Paris, France
| | - Sarah Martinez
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, F-75205 Paris, France
| | - Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg & Division of Metabolic Diseases, Technische Universität, München, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg & Division of Metabolic Diseases, Technische Universität, München, Germany
| | - Matthew J Watt
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Iain J Clarke
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Christian L Roth
- Division of Endocrinology, Seattle Children's Hospital Research Institute, WA, USA
| | - Kevin L Grove
- Division Neuroscience, Oregon Health and Science University, Oregon, USA
| | - Michael A Cowley
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia.
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