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Qi Y, Lee NJ, Ip CK, Enriquez R, Tasan R, Zhang L, Herzog H. Agrp-negative arcuate NPY neurons drive feeding under positive energy balance via altering leptin responsiveness in POMC neurons. Cell Metab 2023:S1550-4131(23)00177-8. [PMID: 37201523 DOI: 10.1016/j.cmet.2023.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/14/2022] [Accepted: 04/26/2023] [Indexed: 05/20/2023]
Abstract
Neuropeptide Y (NPY) in the arcuate nucleus (ARC) is known as one of the most critical regulators of feeding. However, how NPY promotes feeding under obese conditions is unclear. Here, we show that positive energy balance, induced by high-fat diet (HFD) or in genetically obese leptin-receptor-deficient mice, leads to elevated Npy2r expression especially on proopiomelanocortin (POMC) neurons, which also alters leptin responsiveness. Circuit mapping identified a subset of ARC agouti-related peptide (Agrp)-negative NPY neurons that control these Npy2r expressing POMC neurons. Chemogenetic activation of this newly discovered circuitry strongly drives feeding, while optogenetic inhibition reduces feeding. Consistent with that, lack of Npy2r on POMC neurons leads to reduced food intake and fat mass. This suggests that under energy surplus conditions, when ARC NPY levels generally drop, high-affinity NPY2R on POMC neurons is still able to drive food intake and enhance obesity development via NPY released predominantly from Agrp-negative NPY neurons.
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Affiliation(s)
- Yue Qi
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, UNSW Sydney, Sydney, NSW, Australia
| | - Nicola J Lee
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, UNSW Sydney, Sydney, NSW, Australia
| | - Chi Kin Ip
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, UNSW Sydney, Sydney, NSW, Australia
| | - Ronaldo Enriquez
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia
| | - Ramon Tasan
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | - Lei Zhang
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, UNSW Sydney, Sydney, NSW, Australia.
| | - Herbert Herzog
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, UNSW Sydney, Sydney, NSW, Australia.
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Han Y, He Y, Harris L, Xu Y, Wu Q. Identification of a GABAergic neural circuit governing leptin signaling deficiency-induced obesity. eLife 2023; 12:e82649. [PMID: 37043384 PMCID: PMC10097419 DOI: 10.7554/elife.82649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 03/24/2023] [Indexed: 04/13/2023] Open
Abstract
The hormone leptin is known to robustly suppress food intake by acting upon the leptin receptor (LepR) signaling system residing within the agouti-related protein (AgRP) neurons of the hypothalamus. However, clinical studies indicate that leptin is undesirable as a therapeutic regiment for obesity, which is at least partly attributed to the poorly understood complex secondary structure and key signaling mechanism of the leptin-responsive neural circuit. Here, we show that the LepR-expressing portal neurons send GABAergic projections to a cohort of α3-GABAA receptor expressing neurons within the dorsomedial hypothalamic nucleus (DMH) for the control of leptin-mediated obesity phenotype. We identified the DMH as a key brain region that contributes to the regulation of leptin-mediated feeding. Acute activation of the GABAergic AgRP-DMH circuit promoted food intake and glucose intolerance, while activation of post-synaptic MC4R neurons in the DMH elicited exactly opposite phenotypes. Rapid deletion of LepR from AgRP neurons caused an obesity phenotype which can be rescued by blockage of GABAA receptor in the DMH. Consistent with behavioral results, these DMH neurons displayed suppressed neural activities in response to hunger or hyperglycemia. Furthermore, we identified that α3-GABAA receptor signaling within the DMH exerts potent bi-directional regulation of the central effects of leptin on feeding and body weight. Together, our results demonstrate a novel GABAergic neural circuit governing leptin-mediated feeding and energy balance via a unique α3-GABAA signaling within the secondary leptin-responsive neural circuit, constituting a new avenue for therapeutic interventions in the treatment of obesity and associated comorbidities.
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Affiliation(s)
- Yong Han
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of MedicineHoustonUnited States
| | - Yang He
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of MedicineHoustonUnited States
| | - Lauren Harris
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of MedicineHoustonUnited States
| | - Yong Xu
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of MedicineHoustonUnited States
| | - Qi Wu
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of MedicineHoustonUnited States
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3
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Montal E, Lumaquin D, Ma Y, Suresh S, White RM. Modeling the effects of genetic- and diet-induced obesity on melanoma progression in zebrafish. Dis Model Mech 2023; 16:285858. [PMID: 36472402 PMCID: PMC9884122 DOI: 10.1242/dmm.049671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 11/27/2022] [Indexed: 12/12/2022] Open
Abstract
Obesity is a rising concern and associated with an increase in numerous cancers, often in a sex-specific manner. Preclinical models are needed to deconvolute the intersection between obesity, sex and melanoma. Here, we generated a zebrafish system that can be used as a platform for studying these factors. We studied how germline overexpression of Agrp along with a high-fat diet affects melanomas dependent on BRAFV600E and loss of p53. This revealed an increase in tumor incidence and area in male, but not female, obese fish, consistent with the clinical literature. We then determined whether this was further affected by additional somatic mutations in the clinically relevant genes rb1 or ptena/b. We found that the male obesogenic effect on melanoma was present with tumors generated with BRAF;p53;Rb1 but not BRAF;p53;Pten. These data indicate that both germline (Agrp) and somatic (BRAF, Rb1) mutations contribute to obesity-related effects in melanoma. Given the rapid genetic tools available in the zebrafish, this provides a high-throughput system to dissect the interactions of genetics, diet, sex and host factors in obesity-related cancers.
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Affiliation(s)
- Emily Montal
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Dianne Lumaquin
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - Yilun Ma
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - Shruthy Suresh
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Richard M. White
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA,Author for correspondence ()
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Norland S, Eilertsen M, Rønnestad I, Helvik JV, Gomes AS. Mapping key neuropeptides involved in the melanocortin system in Atlantic salmon (Salmo salar) brain. J Comp Neurol 2023; 531:89-115. [PMID: 36217593 PMCID: PMC9828751 DOI: 10.1002/cne.25415] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 01/12/2023]
Abstract
The melanocortin system is a key regulator of appetite and food intake in vertebrates. This system includes the neuropeptides neuropeptide y (NPY), agouti-related peptide (AGRP), cocaine- and amphetamine-regulated transcript (CART), and pro-opiomelanocortin (POMC). An important center for appetite control in mammals is the hypothalamic arcuate nucleus, with neurons that coexpress either the orexigenic NPY/AGRP or the anorexigenic CART/POMC neuropeptides. In ray-finned fishes, such a center is less characterized. The Atlantic salmon (Salmo salar) has multiple genes of these neuropeptides due to whole-genome duplication events. To better understand the potential involvement of the melanocortin system in appetite and food intake control, we have mapped the mRNA expression of npy, agrp, cart, and pomc in the brain of Atlantic salmon parr using in situ hybridization. After identifying hypothalamic mRNA expression, we investigated the possible intracellular coexpression of npy/agrp and cart/pomc in the tuberal hypothalamus by fluorescent in situ hybridization. The results showed that the neuropeptides were widely distributed, especially in sensory and neuroendocrine brain regions. In the hypothalamic lateral tuberal nucleus, the putative homolog to the mammalian arcuate nucleus, npya, agrp1, cart2b, and pomca were predominantly localized in distinct neurons; however, some neurons coexpressed cart2b/pomca. This is the first demonstration of coexpression of cart2b/pomca in the tuberal hypothalamus of a teleost. Collectively, our data suggest that the lateral tuberal nucleus is the center for appetite control in salmon, similar to that of mammals. Extrahypothalamic brain regions might also be involved in regulating food intake, including the olfactory bulb, telencephalon, midbrain, and hindbrain.
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Affiliation(s)
- Sissel Norland
- Department of Biological SciencesUniversity of BergenBergenNorway
| | | | - Ivar Rønnestad
- Department of Biological SciencesUniversity of BergenBergenNorway
| | - Jon Vidar Helvik
- Department of Biological SciencesUniversity of BergenBergenNorway
| | - Ana S. Gomes
- Department of Biological SciencesUniversity of BergenBergenNorway
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Reinoß P, Ciglieri E, Minére M, Bremser S, Klein A, Löhr H, Fuller PM, Büschges A, Kloppenburg P, Fenselau H, Hammerschmidt M. Hypothalamic Pomc Neurons Innervate the Spinal Cord and Modulate the Excitability of Premotor Circuits. Curr Biol 2020; 30:4579-4593.e7. [PMID: 32976803 DOI: 10.1016/j.cub.2020.08.103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 07/30/2020] [Accepted: 08/27/2020] [Indexed: 12/20/2022]
Abstract
Locomotion requires energy, yet animals need to increase locomotion in order to find and consume food in energy-deprived states. While such energy homeostatic coordination suggests brain origin, whether the central melanocortin 4 receptor (Mc4r) system directly modulates locomotion through motor circuits is unknown. Here, we report that hypothalamic Pomc neurons in zebrafish and mice have long-range projections into spinal cord regions harboring Mc4r-expressing V2a interneurons, crucial components of the premotor networks. Furthermore, in zebrafish, Mc4r activation decreases the excitability of spinal V2a neurons as well as swimming and foraging, while systemic or V2a neuron-specific blockage of Mc4r promotes locomotion. In contrast, in mice, electrophysiological recordings revealed that two-thirds of V2a neurons in lamina X are excited by the Mc4r agonist α-MSH, and acute inhibition of Mc4r signaling reduces locomotor activity. In addition, we found other Mc4r neurons in spinal lamina X that are inhibited by α-MSH, which is in line with previous studies in rodents where Mc4r agonists reduced locomotor activity. Collectively, our studies identify spinal V2a interneurons as evolutionary conserved second-order neurons of the central Mc4r system, providing a direct anatomical and functional link between energy homeostasis and locomotor control systems. The net effects of this modulatory system on locomotor activity can vary between different vertebrate species and, possibly, even within one species. We discuss the biological sense of this phenomenon in light of the ambiguity of locomotion on energy balance and the different living conditions of the different species.
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Garau C, Blomeley C, Burdakov D. Orexin neurons and inhibitory Agrp→orexin circuits guide spatial exploration in mice. J Physiol 2020; 598:4371-4383. [PMID: 32667686 DOI: 10.1113/jp280158] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/13/2020] [Indexed: 01/08/2023] Open
Abstract
KEY POINTS Photoinhibition of endogenous activity of lateral hypothalamic orexin neurons causes place preference and reduces innate avoidance Endogenous activity of orexin neurons correlates with place preference Mediobasal hypothalamic Agrp neurons inhibit orexin neurons via GABA, and chemogenetic suppression of Agrp neurons increases avoidance in an orexin receptor-dependent manner. ABSTRACT Hypothalamic orexin/hypocretin neurons integrate multiple sensory cues and project brain-wide to orchestrate diverse innate behaviours. Their loss impairs many context-appropriate actions, but the motivational characteristics of orexin cell activity remain unclear. We and others previously approached this question by artificial orexin stimulation, which could induce either rewarding (positive valence) or aversive (negative valence) brain activity. It is unknown to what extent such approaches replicate natural/endogenous orexin signals, which rapidly fluctuate during wakefulness. Here we took an alternative approach, focusing on observing and silencing natural orexin cell signals associated with a fundamental innate behaviour, self-paced spatial exploration. We found that mice are more likely to stay in places paired with orexin cell optosilencing. The orexin cell optosilencing also reduced avoidance of places that mice find innately aversive. Correspondingly, calcium recordings revealed that orexin cell activity rapidly reduced upon exiting the innately aversive places. Furthermore, we provide optogenetic evidence for an inhibitory GABAergic Agrp→orexin hypothalamic neurocircuit, and find that Agrp cell suppression increases innate avoidance behaviour, consistent with orexin disinhibition. These results imply that exploration may be motivated and oriented by a need to reduce aversive orexin cell activity, and suggest a hypothalamic circuit for fine-tuning orexin signals to changing ethological priorities.
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Affiliation(s)
- Celia Garau
- The Francis Crick Institute, London, NW1 1AT, UK
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7
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Park S, Oh TS, Kim S, Kim EK. Palmitate-induced autophagy liberates monounsaturated fatty acids and increases Agrp expression in hypothalamic cells. Anim Cells Syst (Seoul) 2019; 23:384-391. [PMID: 31853375 PMCID: PMC6913639 DOI: 10.1080/19768354.2019.1696407] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 11/15/2019] [Indexed: 12/13/2022] Open
Abstract
Fatty acids regulate food intake, although the exact mechanism remains unknown. Emerging evidence suggests that intracellular free fatty acids generated by starvation-induced autophagy regulate food intake. Starvation for 6 h elevated fatty acids such as palmitate, oleate, arachidonate, eicosatrienoate, and docosahexaenoate in the mouse serum. Among them, palmitate induced lipophagy, an autophagic degradation of cellular lipid droplets, in agouti-related peptide (Agrp)-expressing hypothalamic cells. Palmitate-induced lipophagy increased both Agrp expression and the contents of monounsaturated fatty acids such as palmitoleate, oleate, and (E)-9-octadecanoate, whereas these effects were blunted by autophagy deficiency. These findings support the role of free fatty acids in hypothalamic autophagy that regulates the appetite by changing the expression of orexigenic neuropeptides.
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Affiliation(s)
- Seokjae Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea.,Neurometabolomics Research Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Tae Seok Oh
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Seolsong Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Eun-Kyoung Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea.,Neurometabolomics Research Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
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8
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Bochukova EG, Lawler K, Croizier S, Keogh JM, Patel N, Strohbehn G, Lo KK, Humphrey J, Hokken-Koelega A, Damen L, Donze S, Bouret SG, Plagnol V, Farooqi IS. A Transcriptomic Signature of the Hypothalamic Response to Fasting and BDNF Deficiency in Prader-Willi Syndrome. Cell Rep 2019; 22:3401-3408. [PMID: 29590610 PMCID: PMC5896230 DOI: 10.1016/j.celrep.2018.03.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/07/2018] [Accepted: 03/05/2018] [Indexed: 01/07/2023] Open
Abstract
Transcriptional analysis of brain tissue from people with molecularly defined causes of obesity may highlight disease mechanisms and therapeutic targets. We performed RNA sequencing of hypothalamus from individuals with Prader-Willi syndrome (PWS), a genetic obesity syndrome characterized by severe hyperphagia. We found that upregulated genes overlap with the transcriptome of mouse Agrp neurons that signal hunger, while downregulated genes overlap with the expression profile of Pomc neurons activated by feeding. Downregulated genes are expressed mainly in neuronal cells and contribute to neurogenesis, neurotransmitter release, and synaptic plasticity, while upregulated, predominantly microglial genes are involved in inflammatory responses. This transcriptional signature may be mediated by reduced brain-derived neurotrophic factor expression. Additionally, we implicate disruption of alternative splicing as a potential molecular mechanism underlying neuronal dysfunction in PWS. Transcriptomic analysis of the human hypothalamus may identify neural mechanisms involved in energy homeostasis and potential therapeutic targets for weight loss. Overlap between genes expressed in human PWS hypothalamus and mouse Agrp neurons Downregulated genes are involved in neuronal development SNORD116 deletion reduces neural development and survival in cells Alternative splicing is disturbed in PWS
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Affiliation(s)
- Elena G Bochukova
- 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; The Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK.
| | - 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
| | - Sophie Croizier
- The Saban Research Institute, Developmental Neuroscience Program, and Diabetes and Obesity Program, Children's Hospital Los Angeles, Center for Endocrinology, Diabetes and Metabolism, University of Southern California, Los Angeles, CA 90027, USA; Inserm, Jean-Pierre Aubert Research Center, U1172, University Lille 2, Lille, 59045, France; Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Julia M Keogh
- 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
| | - Nisha Patel
- The Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Garth Strohbehn
- 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
| | - Kitty K Lo
- University College London Genetics Institute (UGI), Department of Genetics, Environment and Evolution, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Jack Humphrey
- University College London Genetics Institute (UGI), Department of Genetics, Environment and Evolution, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK; Department of Neurodegenerative Disease, University College London Institute of Neurology, London, WC1N 3BG, UK
| | - Anita Hokken-Koelega
- Erasmus University Medical Center, Rotterdam, the Netherlands; Dutch Growth Research Foundation, Rotterdam, the Netherlands
| | - Layla Damen
- Erasmus University Medical Center, Rotterdam, the Netherlands; Dutch Growth Research Foundation, Rotterdam, the Netherlands
| | - Stephany Donze
- Erasmus University Medical Center, Rotterdam, the Netherlands; Dutch Growth Research Foundation, Rotterdam, the Netherlands
| | - Sebastien G Bouret
- The Saban Research Institute, Developmental Neuroscience Program, and Diabetes and Obesity Program, Children's Hospital Los Angeles, Center for Endocrinology, Diabetes and Metabolism, University of Southern California, Los Angeles, CA 90027, USA; Inserm, Jean-Pierre Aubert Research Center, U1172, University Lille 2, Lille, 59045, France
| | - Vincent Plagnol
- University College London Genetics Institute (UGI), Department of Genetics, Environment and Evolution, University College London, Darwin Building, Gower Street, London, WC1E 6BT, 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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