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Srour N, Caron A, Michael NJ. Do POMC neurons have a sweet tooth for leptin? Special issue: Role of nutrients in nervous control of energy balance. Biochimie 2024; 223:179-187. [PMID: 36122808 DOI: 10.1016/j.biochi.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 08/29/2022] [Accepted: 09/09/2022] [Indexed: 11/19/2022]
Abstract
Coordinated detection of changes in metabolic state by the nervous system is fundamental for survival. Hypothalamic pro-opiomelanocortin (POMC) neurons play a critical role in integrating metabolic signals, including leptin levels. They also coordinate adaptative responses and thus represent an important relay in the regulation of energy balance. Despite a plethora of work documenting the effects of individual hormones, nutrients, and neuropeptides on POMC neurons, the importance for crosstalk and additive effects between such signaling molecules is still underexplored. The ability of the metabolic state and the concentrations of nutrients, such as glucose, to influence leptin's effects on POMC neurons appears critical for understanding the function and complexity of this regulatory network. Here, we summarize the current knowledge on the effects of leptin on POMC neuron electrical excitability and discuss factors potentially contributing to variability in these effects, with a particular focus on the mouse models that have been developed and the importance of extracellular glucose levels. This review highlights the importance of the metabolic "environment" for determining hypothalamic neuronal responsiveness to metabolic cues and for determining the fundamental effects of leptin on the activity of hypothalamic POMC neurons.
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Affiliation(s)
- Nader Srour
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 chemin Sainte-Foy, Québec, QC, G1V 4G5, Canada; Faculté de Pharmacie, Université Laval, Québec, QC, Canada
| | - Alexandre Caron
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 chemin Sainte-Foy, Québec, QC, G1V 4G5, Canada; Faculté de Pharmacie, Université Laval, Québec, QC, Canada; Montreal Diabetes Research Center, QC, Canada.
| | - Natalie Jane Michael
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 chemin Sainte-Foy, Québec, QC, G1V 4G5, Canada; Faculté de Pharmacie, Université Laval, Québec, QC, Canada.
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2
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Wang J, O'Reilly M, Cooper IA, Chehrehasa F, Moody H, Beecher K. Mapping GABAergic projections that mediate feeding. Neurosci Biobehav Rev 2024; 163:105743. [PMID: 38821151 DOI: 10.1016/j.neubiorev.2024.105743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
Neuroscience offers important insights into the pathogenesis and treatment of obesity by investigating neural circuits underpinning appetite and feeding. Gamma-aminobutyric acid (GABA), one of the most abundant neurotransmitters in the brain, and its associated receptors represent an array of pharmacologically targetable mediators of appetite signalling. Targeting the GABAergic system is therefore an increasingly investigated approach to obesity treatment. However, the many GABAergic projections that control feeding have yet to be collectively analysed. This review provides a comprehensive analysis of the relationship between GABAergic signalling and appetite by examining both foundational studies and the results of newly emerging chemogenetic/optogenetic experiments. A current snapshot of these efforts to map GABAergic projections influencing appetite is provided, and potential avenues for further investigation are provided.
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Affiliation(s)
- Joshua Wang
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, 2 George Street, Brisbane 4000, QLD, Australia.
| | - Max O'Reilly
- UQ Centre for Clinical Research, Faculty of Medicine, University of Queensland, Building 71/918 Royal Brisbane and Women's Hospital Campus, Herston 4029, QLD, Australia
| | | | - Fatemeh Chehrehasa
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, 2 George Street, Brisbane 4000, QLD, Australia
| | - Hayley Moody
- Queensland University of Technology, 2 George Street, Brisbane 4000, QLD, Australia
| | - Kate Beecher
- UQ Centre for Clinical Research, Faculty of Medicine, University of Queensland, Building 71/918 Royal Brisbane and Women's Hospital Campus, Herston 4029, QLD, Australia
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3
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Jovanovic VM, Narisu N, Bonnycastle LL, Tharakan R, Mesch KT, Glover HJ, Yan T, Sinha N, Sen C, Castellano D, Yang S, Blivis D, Ryu S, Bennett DF, Rosales-Soto G, Inman J, Ormanoglu P, LeClair CA, Xia M, Schneider M, Hernandez-Ochoa EO, Erdos MR, Simeonov A, Chen S, Singeç I, Collins FS, Doege CA, Tristan CA. Scalable Hypothalamic Arcuate Neuron Differentiation from Human Pluripotent Stem Cells Suitable for Modeling Metabolic and Reproductive Disorders. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.27.601062. [PMID: 39005353 PMCID: PMC11244856 DOI: 10.1101/2024.06.27.601062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
The hypothalamus, composed of several nuclei, is essential for maintaining our body's homeostasis. The arcuate nucleus (ARC), located in the mediobasal hypothalamus, contains neuronal populations with eminent roles in energy and glucose homeostasis as well as reproduction. These neuronal populations are of great interest for translational research. To fulfill this promise, we used a robotic cell culture platform to provide a scalable and chemically defined approach for differentiating human pluripotent stem cells (hPSCs) into pro-opiomelanocortin (POMC), somatostatin (SST), tyrosine hydroxylase (TH) and gonadotropin-releasing hormone (GnRH) neuronal subpopulations with an ARC-like signature. This robust approach is reproducible across several distinct hPSC lines and exhibits a stepwise induction of key ventral diencephalon and ARC markers in transcriptomic profiling experiments. This is further corroborated by direct comparison to human fetal hypothalamus, and the enriched expression of genes implicated in obesity and type 2 diabetes (T2D). Genome-wide chromatin accessibility profiling by ATAC-seq identified accessible regulatory regions that can be utilized to predict candidate enhancers related to metabolic disorders and hypothalamic development. In depth molecular, cellular, and functional experiments unveiled the responsiveness of the hPSC-derived hypothalamic neurons to hormonal stimuli, such as insulin, neuropeptides including kisspeptin, and incretin mimetic drugs such as Exendin-4, highlighting their potential utility as physiologically relevant cellular models for disease studies. In addition, differential glucose and insulin treatments uncovered adaptability within the generated ARC neurons in the dynamic regulation of POMC and insulin receptors. In summary, the establishment of this model represents a novel, chemically defined, and scalable platform for manufacturing large numbers of hypothalamic arcuate neurons and serves as a valuable resource for modeling metabolic and reproductive disorders.
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4
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Diao S, Chen C, Benani A, Magnan C, Van Steenwinckel J, Gressens P, Cruciani-Guglielmacci C, Jacquens A, Bokobza C. Preterm birth: A neuroinflammatory origin for metabolic diseases? Brain Behav Immun Health 2024; 37:100745. [PMID: 38511150 PMCID: PMC10950814 DOI: 10.1016/j.bbih.2024.100745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/16/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024] Open
Abstract
Preterm birth and its related complications have become more and more common as neonatal medicine advances. The concept of "developmental origins of health and disease" has raised awareness of adverse perinatal events in the development of diseases later in life. To explore this concept, we propose that encephalopathy of prematurity (EoP) as a potential pro-inflammatory early life event becomes a novel risk factor for metabolic diseases in children/adolescents and adulthood. Here, we review epidemiological evidence that links preterm birth to metabolic diseases and discuss possible synergic roles of preterm birth and neuroinflammation from EoP in the development of metabolic diseases. In addition, we explore theoretical underlying mechanisms regarding developmental programming of the energy control system and HPA axis.
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Affiliation(s)
- Sihao Diao
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, 201102, China
- Key Laboratory of Neonatal Diseases, National Health Commission, China
| | - Chao Chen
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, 201102, China
- Key Laboratory of Neonatal Diseases, National Health Commission, China
| | - Alexandre Benani
- CSGA, Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS, INRAE, Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | | | | | - Pierre Gressens
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
| | | | - Alice Jacquens
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
- Department of Anesthesia and Critical Care, APHP-Sorbonne University, Hôpital La Pitié- Salpêtrière, Paris, France
| | - Cindy Bokobza
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
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Lorch CM, Hayes NW, Xia JL, Fleps SW, McMorrow HE, Province HS, Frydman JA, Parker JG, Beutler LR. Sucrose overconsumption impairs AgRP neuron dynamics and promotes palatable food intake. Cell Rep 2024; 43:113675. [PMID: 38224492 PMCID: PMC10922425 DOI: 10.1016/j.celrep.2024.113675] [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: 06/27/2023] [Revised: 11/17/2023] [Accepted: 01/02/2024] [Indexed: 01/17/2024] Open
Abstract
Rapid gut-brain communication is critical to maintain energy balance and is disrupted in diet-induced obesity. In particular, the role of carbohydrate overconsumption in the regulation of interoceptive circuits in vivo requires further investigation. Here, we report that an obesogenic high-sucrose diet (HSD) selectively blunts silencing of hunger-promoting agouti-related protein (AgRP) neurons following intragastric delivery of glucose, whereas we previously showed that overconsumption of a high-fat diet (HFD) selectively attenuates lipid-induced neural silencing. By contrast, both HSD and HFD reversibly dampen rapid AgRP neuron inhibition following chow presentation and promote intake of more palatable foods. Our findings reveal that excess sugar and fat pathologically modulate feeding circuit activity in both macronutrient-dependent and -independent ways and thus may additively exacerbate obesity.
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Affiliation(s)
- Carolyn M Lorch
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA; Driskill Graduate Program in Life Sciences, Northwestern University, Chicago, IL 60611, USA
| | - Nikolas W Hayes
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA; Interdepartmental Neuroscience Graduate Program, Northwestern University, Chicago, IL 60611, USA
| | - Jessica L Xia
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Stefan W Fleps
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Neuroscience, Northwestern University, Chicago, IL 60611, USA
| | - Hayley E McMorrow
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA; Interdepartmental Neuroscience Graduate Program, Northwestern University, Chicago, IL 60611, USA
| | - Haley S Province
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA; Interdepartmental Neuroscience Graduate Program, Northwestern University, Chicago, IL 60611, USA
| | - Joshua A Frydman
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Jones G Parker
- Department of Neuroscience, Northwestern University, Chicago, IL 60611, USA
| | - Lisa R Beutler
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL 60611, USA.
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Mata-Pacheco V, Hernandez J, Varma N, Xu J, Sayers S, Le N, Wagner EJ. Dynamic, sex- and diet-specific pleiotropism in the PAC1 receptor-mediated regulation of arcuate proopiomelanocortin and Neuropeptide Y/Agouti related peptide neuronal excitability by anorexigenic ventromedial nucleus PACAP neurons. J Neuroendocrinol 2024; 36:e13357. [PMID: 38056947 DOI: 10.1111/jne.13357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 12/08/2023]
Abstract
This study furthers the investigation of how pituitary adenylate cyclase activating polypeptide (PACAP) and the PAC1 receptor (PAC1R) regulate the homeostatic energy balance circuitry. We hypothesized that apoptotic ablation of PACAP neurones in the hypothalamic ventromedial nucleus (VMN) would affect both energy intake and energy expenditure. We also hypothesized that selective PAC1R knockdown would impair the PACAP-induced excitation in anorexigenic proopiomelanocortin (POMC) neurones and inhibition of orexigenic neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurones in the hypothalamic arcuate nucleus (ARC). The results show CASPASE-3-induced ablation of VMN PACAP neurones leads to increased energy intake and meal frequency as well as decreased energy expenditure in lean animals. The effects were more robust in obese males, whereas we saw the opposite effects in obese females. We then utilized visualized whole-cell patch clamp recordings in hypothalamic slices. PAC1R knockdown in POMC neurones diminishes the PACAP-induced depolarization, increase in firing, decreases in energy intake and meal size, as well as increases in CO2 production and O2 consumption. Similarly, the lack of expression of the PAC1R in NPY/AgRP neurones greatly attenuates the PACAP-induced hyperpolarization, suppression of firing, decreases in energy intake and meal frequency, as well as increases in energy expenditure. The PACAP response in NPY/AgRP neurones switched from predominantly inhibitory to excitatory in fasted animals. Finally, the anorexigenic effect of PACAP was potentiated when oestradiol was injected into the ARC in ovariectomized females. This study demonstrates the critical role of anorexigenic VMN PACAP neurones and the PAC1R in exciting POMC and inhibiting NPY/AgRP neurons to control homeostatic feeding.
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Affiliation(s)
- Veronica Mata-Pacheco
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California, USA
| | - Jennifer Hernandez
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
| | - Nandini Varma
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
| | - Jenny Xu
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
| | - Sarah Sayers
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
| | - Nikki Le
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
| | - Edward J Wagner
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California, USA
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
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Copeland DS, Gugel A, Gantz SC. Potentiation of neuronal activity by tonic GluD1 current in brain slices. EMBO Rep 2023:e56801. [PMID: 37154294 DOI: 10.15252/embr.202356801] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023] Open
Abstract
Ion channel function of native delta glutamate receptors (GluDR ) is incompletely understood. Previously, we and others have shown that activation of Gαq protein-coupled receptors (GqPCR) produces a slow inward current carried by GluD1R . GluD1R also carries a tonic cation current of unknown cause. Here, using voltage-clamp electrophysiological recordings from adult mouse brain slices containing the dorsal raphe nucleus, we find no role of ongoing G-protein-coupled receptor activity in generating or sustaining tonic GluD1R currents. Neither augmentation nor disruption of G protein activity affects tonic GluD1R currents, suggesting that ongoing G-protein-coupled receptor activity does not give rise to tonic GluD1R currents. Further, the tonic GluD1R current is unaffected by the addition of external glycine or D-serine, which influences GluD2R current at millimolar concentrations. Instead, GqPCR-stimulated and tonic GluD1R currents are regulated by physiological levels of external calcium. In current-clamp recordings, block of GluD1R channels hyperpolarizes the membrane by ~7 mV at subthreshold potentials, reducing excitability. Thus, GluD1R carries a G-protein-independent tonic current that contributes to subthreshold neuronal excitation in the dorsal raphe nucleus.
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Affiliation(s)
- Daniel S Copeland
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Aleigha Gugel
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Stephanie C Gantz
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
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Schlögl H, Janssen L, Fasshauer M, Miehle K, Villringer A, Stumvoll M, Mueller K. Reward Processing During Monetary Incentive Delay Task After Leptin Substitution in Lipodystrophy-an fMRI Case Series. J Endocr Soc 2023; 7:bvad052. [PMID: 37180211 PMCID: PMC10174197 DOI: 10.1210/jendso/bvad052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Indexed: 05/16/2023] Open
Abstract
Context Behaviorally, the most pronounced effects of leptin substitution in leptin deficiency are the hunger-decreasing and postprandial satiety-prolonging effects of the adipokine. Previously, with functional magnetic resonance imaging (MRI), we and others showed that eating behavior-controlling effects are at least in part conveyed by the reward system. However, to date, it is unclear if leptin only modulates eating behavior specific brain reward action or if it also alters the reward function of the brain unrelated to eating behavior. Objective We investigated with functional MRI the effects of metreleptin on the reward system in a reward task unrelated to eating behavior, the monetary incentive delay task. Design Measurements in 4 patients with the very rare disease of lipodystrophy (LD), resulting in leptin deficiency, and 3 untreated healthy control persons were performed at 4 different time points: before start and over 12 weeks of metreleptin treatment. Inside the MRI scanner, participants performed the monetary incentive delay task and brain activity during the reward receipt phase of the trial was analyzed. Results We found a reward-related brain activity decrease in our 4 patients with LD over the 12 weeks of metreleptin treatment in the subgenual region, a brain area associated with the reward network, which was not observed in our 3 untreated healthy control persons. Conclusions These results suggest that leptin replacement in LD induces changes of brain activity during reward reception processing completely unrelated to eating behavior or food stimuli. This could suggest eating behavior-unrelated functions of leptin in the human reward system. Trial registration The trial is registered as trial No. 147/10-ek at the ethics committee of the University of Leipzig and at the State Directorate of Saxony (Landesdirektion Sachsen).
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Affiliation(s)
- Haiko Schlögl
- Department of Medicine, University Hospital Leipzig, 04103 Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, 04103 Leipzig, Germany
| | - Lieneke Janssen
- Max-Planck-Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
| | - Mathias Fasshauer
- Institute of Nutritional Sciences, Justus-Liebig-University, 35390 Giessen, Germany
| | - Konstanze Miehle
- Department of Medicine, University Hospital Leipzig, 04103 Leipzig, Germany
| | - Arno Villringer
- Max-Planck-Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
- Day Clinic of Cognitive Neurology, University of Leipzig, 04103 Leipzig, Germany
| | - Michael Stumvoll
- Department of Medicine, University Hospital Leipzig, 04103 Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, 04103 Leipzig, Germany
| | - Karsten Mueller
- Max-Planck-Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, 12000 Prague, Czech Republic
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Grzelka K, Wilhelms H, Dodt S, Dreisow ML, Madara JC, Walker SJ, Wu C, Wang D, Lowell BB, Fenselau H. A synaptic amplifier of hunger for regaining body weight in the hypothalamus. Cell Metab 2023; 35:770-785.e5. [PMID: 36965483 PMCID: PMC10160008 DOI: 10.1016/j.cmet.2023.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 12/15/2022] [Accepted: 03/01/2023] [Indexed: 03/27/2023]
Abstract
Restricting caloric intake effectively reduces body weight, but most dieters fail long-term adherence to caloric deficit and eventually regain lost weight. Hypothalamic circuits that control hunger drive critically determine body weight; yet, how weight loss sculpts these circuits to motivate food consumption until lost weight is regained remains unclear. Here, we probe the contribution of synaptic plasticity in discrete excitatory afferents on hunger-promoting AgRP neurons. We reveal a crucial role for activity-dependent, remarkably long-lasting amplification of synaptic activity originating from paraventricular hypothalamus thyrotropin-releasing (PVHTRH) neurons in long-term body weight control. Silencing PVHTRH neurons inhibits the potentiation of excitatory input to AgRP neurons and diminishes concomitant regain of lost weight. Brief stimulation of the pathway is sufficient to enduringly potentiate this glutamatergic hunger synapse and triggers an NMDAR-dependent gaining of body weight that enduringly persists. Identification of this activity-dependent synaptic amplifier provides a previously unrecognized target to combat regain of lost weight.
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Affiliation(s)
- Katarzyna Grzelka
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Hannah Wilhelms
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Stephan Dodt
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Marie-Luise Dreisow
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Joseph C Madara
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Samuel J Walker
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Chen Wu
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Daqing Wang
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Bradford B Lowell
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02215, USA.
| | - Henning Fenselau
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Straße 26, Cologne 50931, Germany.
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10
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Van Huynh T, Rethi L, Rethi L, Chen CH, Chen YJ, Kao YH. The Complex Interplay between Imbalanced Mitochondrial Dynamics and Metabolic Disorders in Type 2 Diabetes. Cells 2023; 12:1223. [PMID: 37174622 PMCID: PMC10177489 DOI: 10.3390/cells12091223] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/15/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a global burden, with an increasing number of people affected and increasing treatment costs. The advances in research and guidelines improve the management of blood glucose and related diseases, but T2DM and its complications are still a big challenge in clinical practice. T2DM is a metabolic disorder in which insulin signaling is impaired from reaching its effectors. Mitochondria are the "powerhouses" that not only generate the energy as adenosine triphosphate (ATP) using pyruvate supplied from glucose, free fatty acid (FFA), and amino acids (AA) but also regulate multiple cellular processes such as calcium homeostasis, redox balance, and apoptosis. Mitochondrial dysfunction leads to various diseases, including cardiovascular diseases, metabolic disorders, and cancer. The mitochondria are highly dynamic in adjusting their functions according to cellular conditions. The shape, morphology, distribution, and number of mitochondria reflect their function through various processes, collectively known as mitochondrial dynamics, including mitochondrial fusion, fission, biogenesis, transport, and mitophagy. These processes determine the overall mitochondrial health and vitality. More evidence supports the idea that dysregulated mitochondrial dynamics play essential roles in the pathophysiology of insulin resistance, obesity, and T2DM, as well as imbalanced mitochondrial dynamics found in T2DM. This review updates and discusses mitochondrial dynamics and the complex interactions between it and metabolic disorders.
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Affiliation(s)
- Tin Van Huynh
- International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
- Department of Interventional Cardiology, Thong Nhat Hospital, Ho Chi Minh City 700000, Vietnam
| | - Lekha Rethi
- School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan
- International Ph.D. Program for Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan
| | - Lekshmi Rethi
- International Ph.D. Program for Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan
| | - Chih-Hwa Chen
- School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan
- Department of Orthopedics, Taipei Medical University-Shuang Ho Hospital, New Taipei City 23561, Taiwan
- School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 11031, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
- Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei 11031, Taiwan
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11
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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] [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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12
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Sharafeddin F, Ghaly M, Simon TB, Ontiveros-Ángel P, Figueroa JD. Prefrontal cortical protease TACE/ADAM17 is involved in neuroinflammation and stress-related eating alterations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.23.525269. [PMID: 36747666 PMCID: PMC9900811 DOI: 10.1101/2023.01.23.525269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Childhood traumatic stress profoundly affects prefrontal cortical networks regulating top-down control of eating and body weight. However, the neurobiological mechanisms contributing to trauma-induced aberrant eating behaviors remain largely unknown. Traumatic stress influences brain immune responses, which may, in turn, disrupt prefrontal cortical networks and behaviors. The tumor necrosis factor alpha-converting enzyme / a disintegrin and metalloproteinase 17 (TACE/ADAM17) is a sheddase with essential functions in brain maturation, behavior, and neuroinflammation. This study aimed to determine the role of TACE/ADAM17 on traumatic stress-induced disruption of eating patterns. We demonstrate a novel mechanistic connection between prefrontal cortical TACE/ADAM17 and trauma-induced eating behaviors. Fifty-two (52) adolescent Lewis rats (postnatal day, PND, 15) were injected intracerebrally either with a novel Accell™ SMARTpool ADAM17 siRNA or a corresponding siRNA vehicle. The RNAscope Multiplex Fluorescent v2 Assay was used to visualize mRNA expression. Observation cages were used to monitor ethological behaviors in a more naturalistic environment over long periods. We found that traumatic stress blunts startle reactivity and alter eating behaviors (increased intake and disrupted eating patterns). We also found that the rats that received prefrontal cortical TACE/ADAM17 siRNA administration exhibited decreased eating and increased grooming behaviors compared to controls. These changes were associated with decreased AIF-1 expression (a typical marker of microglia and neuroinflammation). This study demonstrates that prefrontal cortical TACE/ADAM17 is involved in neuroinflammation and may play essential roles in regulating feeding patterns under stress conditions. TACE/ADAM17 represents a promising target to ameliorate inflammation-induced brain and behavior alterations.
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Affiliation(s)
- Fransua Sharafeddin
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Mina Ghaly
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Timothy B Simon
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Perla Ontiveros-Ángel
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Johnny D Figueroa
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
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13
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Clinical Trials in Prader-Willi Syndrome: A Review. Int J Mol Sci 2023; 24:ijms24032150. [PMID: 36768472 PMCID: PMC9916985 DOI: 10.3390/ijms24032150] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 12/28/2022] [Accepted: 01/16/2023] [Indexed: 01/25/2023] Open
Abstract
Prader-Willi syndrome (PWS) is a complex, genetic, neurodevelopmental disorder. PWS has three molecular genetic classes. The most common defect is due to a paternal 15q11-q13 deletion observed in about 60% of individuals. This is followed by maternal disomy 15 (both 15 s from the mother), found in approximately 35% of cases. the remaining individuals have a defect of the imprinting center that controls the activity of imprinted genes on chromosome 15. Mild cognitive impairment and behavior problems in PWS include self-injury, anxiety, compulsions, and outbursts in childhood, impacted by genetic subtypes. Food seeking and hyperphagia can lead to morbid obesity and contribute to diabetes and cardiovascular or orthopedic problems. The control of hyperphagia and improving food-related behaviors are the most important unmet needs in PWS and could be addressed with the development of a new therapeutic agent, as currently no approved therapeutics exist for PWS treatment. The status of clinical trials with existing results for the management of obesity and hyperphagia in PWS will be discussed in this review, including treatments such as beloranib, setmelanotide, a diazoxide choline controlled-release tablet (DCCR), an unacylated ghrelin analogue, oxytocin and related compounds, glucagon-like peptide 1 receptor agonists, surgical intervention, and transcranial direct-current stimulation.
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14
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Puente-Ruiz SC, Jais A. Reciprocal signaling between adipose tissue depots and the central nervous system. Front Cell Dev Biol 2022; 10:979251. [PMID: 36200038 PMCID: PMC9529070 DOI: 10.3389/fcell.2022.979251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
In humans, various dietary and social factors led to the development of increased brain sizes alongside large adipose tissue stores. Complex reciprocal signaling mechanisms allow for a fine-tuned interaction between the two organs to regulate energy homeostasis of the organism. As an endocrine organ, adipose tissue secretes various hormones, cytokines, and metabolites that signal energy availability to the central nervous system (CNS). Vice versa, the CNS is a critical regulator of adipose tissue function through neural networks that integrate information from the periphery and regulate sympathetic nerve outflow. This review discusses the various reciprocal signaling mechanisms in the CNS and adipose tissue to maintain organismal energy homeostasis. We are focusing on the integration of afferent signals from the periphery in neuronal populations of the mediobasal hypothalamus as well as the efferent signals from the CNS to adipose tissue and its implications for adipose tissue function. Furthermore, we are discussing central mechanisms that fine-tune the immune system in adipose tissue depots and contribute to organ homeostasis. Elucidating this complex signaling network that integrates peripheral signals to generate physiological outputs to maintain the optimal energy balance of the organism is crucial for understanding the pathophysiology of obesity and metabolic diseases such as type 2 diabetes.
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15
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Amorim MR, Aung O, Mokhlesi B, Polotsky VY. Leptin-mediated neural targets in obesity hypoventilation syndrome. Sleep 2022; 45:zsac153. [PMID: 35778900 PMCID: PMC9453616 DOI: 10.1093/sleep/zsac153] [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: 03/23/2022] [Revised: 06/20/2022] [Indexed: 07/30/2023] Open
Abstract
Obesity hypoventilation syndrome (OHS) is defined as daytime hypercapnia in obese individuals in the absence of other underlying causes. In the United States, OHS is present in 10%-20% of obese patients with obstructive sleep apnea and is linked to hypoventilation during sleep. OHS leads to high cardiorespiratory morbidity and mortality, and there is no effective pharmacotherapy. The depressed hypercapnic ventilatory response plays a key role in OHS. The pathogenesis of OHS has been linked to resistance to an adipocyte-produced hormone, leptin, a major regulator of metabolism and control of breathing. Mechanisms by which leptin modulates the control of breathing are potential targets for novel therapeutic strategies in OHS. Recent advances shed light on the molecular pathways related to the central chemoreceptor function in health and disease. Leptin signaling in the nucleus of the solitary tract, retrotrapezoid nucleus, hypoglossal nucleus, and dorsomedial hypothalamus, and anatomical projections from these nuclei to the respiratory control centers, may contribute to OHS. In this review, we describe current views on leptin-mediated mechanisms that regulate breathing and CO2 homeostasis with a focus on potential therapeutics for the treatment of OHS.
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Affiliation(s)
- Mateus R Amorim
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - O Aung
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Babak Mokhlesi
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Vsevolod Y Polotsky
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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16
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Chadwick SR, Güler AD. Local Drd1-neurons input to subgroups of arcuate AgRP/NPY-neurons. iScience 2022; 25:104605. [PMID: 35789850 PMCID: PMC9250019 DOI: 10.1016/j.isci.2022.104605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 05/02/2022] [Accepted: 06/08/2022] [Indexed: 11/21/2022] Open
Abstract
Obesity is a pandemic afflicting more than 300 million people worldwide, driven by consumption of calorically dense and highly rewarding foods. Dopamine (DA) signaling has been implicated in neural responses to highly palatable nutrients, but the exact mechanisms through which DA modulates homeostatic feeding circuits remains unknown. A subpopulation of arcuate (ARC) agouti-related peptide (AgRP)/neuropeptide Y (NPY) (ARCAgRP/NPY+) neurons express the D(1A) dopamine receptor (Drd1) and are stimulated by DA, suggesting one potential avenue for dopaminergic regulation of food intake. Using patch clamp electrophysiology, we evaluated the responses of ARC Drd1-expressing (ARCDrd1+) neurons to overnight fasting and leptin. Collectively, ARCDrd1+ neurons were less responsive to caloric deficit than ARCAgRP/NPY+ neurons; however, ARCDrd1+ neurons were inhibited by the satiety hormone leptin. Using Channelrhodopsin-2-Assisted Circuit Mapping, we identified novel subgroups of ARCDrd1+ neurons that inhibit or excite ARCAgRP/NPY+ neurons. These findings suggest dopamine receptive neurons have multimodal actions in food intake circuits.
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Affiliation(s)
- Sean R. Chadwick
- Program in Fundamental Neuroscience and the Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Ali D. Güler
- Program in Fundamental Neuroscience and the Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
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17
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Stincic TL, Kelly MJ. Estrogenic regulation of reproduction and energy homeostasis by a triumvirate of hypothalamic arcuate neurons. J Neuroendocrinol 2022; 34:e13145. [PMID: 35581942 DOI: 10.1111/jne.13145] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 03/31/2022] [Accepted: 04/15/2022] [Indexed: 11/29/2022]
Abstract
Pregnancy is energetically demanding and therefore, by necessity, reproduction and energy balance are inextricably linked. With insufficient or excessive energy stores a female is liable to suffer complications during pregnancy or produce unhealthy offspring. Gonadotropin-releasing hormone neurons are responsible for initiating both the pulsatile and subsequent surge release of luteinizing hormone to control ovulation. Meticulous work has identified two hypothalamic populations of kisspeptin (Kiss1) neurons that are critical for this pattern of release. The involvement of the hypothalamus is unsurprising because its quintessential function is to couple the endocrine and nervous systems, coordinating energy balance and reproduction. Estrogens, more specifically 17β-estradiol (E2 ), orchestrate the activity of a triumvirate of hypothalamic neurons within the arcuate nucleus (ARH) that govern the physiological underpinnings of these behavioral dynamics. Arising from a common progenitor pool, these cells differentiate into ARH kisspeptin, pro-opiomelanocortin (POMC), and agouti related peptide/neuropeptide Y (AgRP) neurons. Although the excitability of all these subpopulations is subject to genomic and rapid estrogenic regulation, Kiss1 neurons are the most sensitive, reflecting their integral function in female fertility. Based on the premise that E2 coordinates autonomic functions around reproduction, we review recent findings on how Kiss1 neurons interact with gonadotropin-releasing hormone, AgRP and POMC neurons, as well as how the rapid membrane-initiated and intracellular signaling cascades activated by E2 in these neurons are critical for control of homeostatic functions supporting reproduction. In particular, we highlight how Kiss1 and POMC neurons conspire to inhibit AgRP neurons and diminish food motivation in service of reproductive success.
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Affiliation(s)
- Todd L Stincic
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR, USA
| | - Martin J Kelly
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR, USA
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
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18
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Le N, Sayers S, Mata-Pacheco V, Wagner EJ. The PACAP Paradox: Dynamic and Surprisingly Pleiotropic Actions in the Central Regulation of Energy Homeostasis. Front Endocrinol (Lausanne) 2022; 13:877647. [PMID: 35721722 PMCID: PMC9198406 DOI: 10.3389/fendo.2022.877647] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/30/2022] [Indexed: 12/11/2022] Open
Abstract
Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP), a pleiotropic neuropeptide, is widely distributed throughout the body. The abundance of PACAP expression in the central and peripheral nervous systems, and years of accompanying experimental evidence, indicates that PACAP plays crucial roles in diverse biological processes ranging from autonomic regulation to neuroprotection. In addition, PACAP is also abundantly expressed in the hypothalamic areas like the ventromedial and arcuate nuclei (VMN and ARC, respectively), as well as other brain regions such as the nucleus accumbens (NAc), bed nucleus of stria terminalis (BNST), and ventral tegmental area (VTA) - suggesting that PACAP is capable of regulating energy homeostasis via both the homeostatic and hedonic energy balance circuitries. The evidence gathered over the years has increased our appreciation for its function in controlling energy balance. Therefore, this review aims to further probe how the pleiotropic actions of PACAP in regulating energy homeostasis is influenced by sex and dynamic changes in energy status. We start with a general overview of energy homeostasis, and then introduce the integral components of the homeostatic and hedonic energy balance circuitries. Next, we discuss sex differences inherent to the regulation of energy homeostasis via these two circuitries, as well as the activational effects of sex steroid hormones that bring about these intrinsic disparities between males and females. Finally, we explore the multifaceted role of PACAP in regulating homeostatic and hedonic feeding through its actions in regions like the NAc, BNST, and in particular the ARC, VMN and VTA that occur in sex- and energy status-dependent ways.
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Affiliation(s)
- Nikki Le
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Sarah Sayers
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Veronica Mata-Pacheco
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Edward J. Wagner
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
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19
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Wellman M, Budin R, Woodside B, Abizaid A. Energetic demands of lactation produce an increase in the expression of growth hormone secretagogue receptor in the hypothalamus and ventral tegmental area of the rat despite a reduction in circulating ghrelin. J Neuroendocrinol 2022; 34:e13126. [PMID: 35365872 DOI: 10.1111/jne.13126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/07/2022] [Accepted: 02/08/2022] [Indexed: 12/26/2022]
Abstract
Lactating rats show changes in the secretion of hormones and brain signals that promote hyperphagia and facilitate the production of milk. Little is known, however, about the role of ghrelin in the mechanisms sustaining lactational hyperphagia. Here, we used Wistar female rats that underwent surgery to sever the galactophores to prevent milk delivery (GC rats) and decrease the energetic drain of milk delivery. We compared plasma acyl-ghrelin concentrations and growth hormone secretagogue receptor (GHSR) mRNA expression in different brain regions of GC rats with those of sham operated lactating and nonlactating rats. Additional lactating and nonlactating rats were implanted with cannulae aimed at the lateral ventricles and were used to compare feeding responses to central ghrelin or GHSR antagonist infusions to those of nonlactating rats receiving similar infusions on day 14-16 postpartum (pp). Results show lower plasma acyl-ghrelin concentrations on day 15 pp sham operated lactating rats compared to GC or nonlactating rats. These changes occur in association with increased GHSR mRNA expression in the hypothalamic arcuate nucleus (ARC) and ventral tegmental area (VTA) of sham operated lactating rats. Despite lactational hyperphagia, infusions of ghrelin (0.25 or 1 μg) resulted in similar increases in food intake in lactating and nonlactating rats. In addition, infusions of the GHSR antagonist JMV3002 (4 μg in 1 μl of vehicle) produced greater suppression of food intake in lactating rats than in nonlactating rats. These data suggest that, despite lower plasma ghrelin, the energetic drain of lactation increases sensitivity to the orexigenic effects of ghrelin in brain regions important for food intake and energy balance, and these events are associated with lactational hyperphagia.
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Affiliation(s)
- Martin Wellman
- Neuroscience Department, Carleton University, Ottawa, Ontario, Canada
| | - Radek Budin
- Centre for Studies in Behavioural Neurobiology, Psychology Department, Concordia University, Montreal, Quebec, Canada
| | - Barbara Woodside
- Centre for Studies in Behavioural Neurobiology, Psychology Department, Concordia University, Montreal, Quebec, Canada
| | - Alfonso Abizaid
- Neuroscience Department, Carleton University, Ottawa, Ontario, Canada
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20
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Jais A, Brüning JC. Arcuate Nucleus-Dependent Regulation of Metabolism-Pathways to Obesity and Diabetes Mellitus. Endocr Rev 2022; 43:314-328. [PMID: 34490882 PMCID: PMC8905335 DOI: 10.1210/endrev/bnab025] [Citation(s) in RCA: 86] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Indexed: 01/12/2023]
Abstract
The central nervous system (CNS) receives information from afferent neurons, circulating hormones, and absorbed nutrients and integrates this information to orchestrate the actions of the neuroendocrine and autonomic nervous systems in maintaining systemic metabolic homeostasis. Particularly the arcuate nucleus of the hypothalamus (ARC) is of pivotal importance for primary sensing of adiposity signals, such as leptin and insulin, and circulating nutrients, such as glucose. Importantly, energy state-sensing neurons in the ARC not only regulate feeding but at the same time control multiple physiological functions, such as glucose homeostasis, blood pressure, and innate immune responses. These findings have defined them as master regulators, which adapt integrative physiology to the energy state of the organism. The disruption of this fine-tuned control leads to an imbalance between energy intake and expenditure as well as deregulation of peripheral metabolism. Improving our understanding of the cellular, molecular, and functional basis of this regulatory principle in the CNS could set the stage for developing novel therapeutic strategies for the treatment of obesity and metabolic syndrome. In this review, we summarize novel insights with a particular emphasis on ARC neurocircuitries regulating food intake and glucose homeostasis and sensing factors that inform the brain of the organismal energy status.
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Affiliation(s)
- Alexander Jais
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany.,Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - Jens C Brüning
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany.,Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,National Center for Diabetes Research (DZD), Neuherberg, Germany
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21
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Distinct Firing Activities of the Hypothalamic Arcuate Nucleus Neurons to Appetite Hormones. Int J Mol Sci 2022; 23:ijms23052609. [PMID: 35269751 PMCID: PMC8910626 DOI: 10.3390/ijms23052609] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/22/2022] [Accepted: 02/22/2022] [Indexed: 01/27/2023] Open
Abstract
The hypothalamic arcuate nucleus (Arc) is a central unit that controls the appetite through the integration of metabolic, hormonal, and neuronal afferent inputs. Agouti-related protein (AgRP), proopiomelanocortin (POMC), and dopaminergic neurons in the Arc differentially regulate feeding behaviors in response to hunger, satiety, and appetite, respectively. At the time of writing, the anatomical and electrophysiological characterization of these three neurons has not yet been intensively explored. Here, we interrogated the overall characterization of AgRP, POMC, and dopaminergic neurons using genetic mouse models, immunohistochemistry, and whole-cell patch recordings. We identified the distinct geographical location and intrinsic properties of each neuron in the Arc with the transgenic lines labelled with cell-specific reporter proteins. Moreover, AgRP, POMC, and dopaminergic neurons had different firing activities to ghrelin and leptin treatments. Ghrelin led to the increased firing rate of dopaminergic and AgRP neurons, and the decreased firing rate of POMC. In sharp contrast, leptin resulted in the decreased firing rate of AgRP neurons and the increased firing rate of POMC neurons, while it did not change the firing rate of dopaminergic neurons in Arc. These findings demonstrate the anatomical and physiological uniqueness of three hypothalamic Arc neurons to appetite control.
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22
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Yu X, Li W. Comparative insights into the integration mechanism of neuropeptides to starvation and temperature stress. Gen Comp Endocrinol 2022; 316:113945. [PMID: 34826429 DOI: 10.1016/j.ygcen.2021.113945] [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: 03/25/2021] [Revised: 08/08/2021] [Accepted: 11/18/2021] [Indexed: 11/29/2022]
Abstract
Stress is known as the process of biological responses evoked by internal or external stimuli. The ability to sense, integrate and respond to stress signals is a requisite for life. Temperature and photoperiod are very important environmental factors for animals. In addition, stress signals can also be inputted from peripheral tissue, such as starvation and inflammation. Through afferent pathways, stress signals input to the central nervous system (CNS), where various signals will integrate, and the integrated information will transmit to the peripheral effectors. As the regulators of neural activity, neuropeptides play important roles in these processes. The present review summarizes recent findings about the integration mechanism of stress signals in the CNS, emphasizing on the role of neuropeptides.
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Affiliation(s)
- Xiaozheng Yu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Wensheng Li
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
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23
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Le N, Hernandez J, Gastelum C, Perez L, Vahrson I, Sayers S, Wagner EJ. Pituitary Adenylate Cyclase Activating Polypeptide Inhibits A 10 Dopamine Neurons and Suppresses the Binge-like Consumption of Palatable Food. Neuroscience 2021; 478:49-64. [PMID: 34597709 DOI: 10.1016/j.neuroscience.2021.09.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 10/20/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) binds to PACAP-specific (PAC1) receptors in multiple hypothalamic areas, especially those regulating energy balance. PACAP neurons in the ventromedial nucleus (VMN) exert anorexigenic effects within the homeostatic energy balance circuitry. Since PACAP can also reduce the consumption of palatable food, we tested the hypothesis that VMN PACAP neurons project to the ventral tegmental area (VTA) to inhibit A10 dopamine neurons via PAC1 receptors and KATP channels, and thereby suppress binge-like consumption. We performed electrophysiological recordings in mesencephalic slices from male PACAP-Cre and tyrosine hydroxylase (TH)-Cre mice. Initially, we injected PACAP (30 pmol) into the VTA, where it suppressed binge intake in wildtype male but not female mice. Subsequent tract tracing studies uncovered projections of VMN PACAP neurons to the VTA. Optogenetic stimulation of VMN PACAP neurons in voltage clamp induced an outward current and increase in conductance in VTA neurons, and a hyperpolarization and decrease in firing in current clamp. These effects were markedly attenuated by the KATP channel blocker tolbutamide (100 μM) and PAC1 receptor antagonist PACAP6-38 (200 nM). In recordings from A10 dopamine neurons in TH-Cre mice, we replicated the outward current by perfusing PACAP1-38 (100 nM). This response was again completely blocked by tolbutamide and PACAP6-38, and associated with a hyperpolarization and decrease in firing. These findings demonstrate that PACAP activates PAC1 receptors and KATP channels to inhibit A10 dopamine neurons and sex-dependently suppress binge-like consumption. Accordingly, they advance our understanding of how PACAP regulates energy homeostasis via the hedonic energy balance circuitry.
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Affiliation(s)
- Nikki Le
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Jennifer Hernandez
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Cassandra Gastelum
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Lynnea Perez
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Isabella Vahrson
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Sarah Sayers
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Edward J Wagner
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA; College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, USA.
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Caron A, Jane Michael N. New Horizons: Is Obesity a Disorder of Neurotransmission? J Clin Endocrinol Metab 2021; 106:e4872-e4886. [PMID: 34117881 DOI: 10.1210/clinem/dgab421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Indexed: 11/19/2022]
Abstract
Obesity is a disease of the nervous system. While some will view this statement as provocative, others will take it as obvious. Whatever our side is, the pharmacology tells us that targeting the nervous system works for promoting weight loss. It works, but at what cost? Is the nervous system a safe target for sustainable treatment of obesity? What have we learned-and unlearned-about the central control of energy balance in the last few years? Herein we provide a thought-provoking exploration of obesity as a disorder of neurotransmission. We discuss the state of knowledge on the brain pathways regulating energy homeostasis that are commonly targeted in anti-obesity therapy and explore how medications affecting neurotransmission such as atypical antipsychotics, antidepressants, and antihistamines relate to body weight. Our goal is to provide the endocrine community with a conceptual framework that will help expending our understanding of the pathophysiology of obesity, a disease of the nervous system.
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Affiliation(s)
- Alexandre Caron
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
- Montreal Diabetes Research Center, Montreal, QC, Canada
| | - Natalie Jane Michael
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
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25
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Gouveia A, de Oliveira Beleza R, Steculorum SM. AgRP neuronal activity across feeding-related behaviours. Eur J Neurosci 2021; 54:7458-7475. [PMID: 34655481 DOI: 10.1111/ejn.15498] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/06/2021] [Accepted: 10/09/2021] [Indexed: 01/24/2023]
Abstract
AgRP neurons trigger one of the most potent orexigenic responses and are both necessary and sufficient for feeding. Recent technical advances for monitoring in vivo neuronal activity have revisited a previously well-established model of AgRP neurons' feeding regulatory effects. Our current understanding of AgRP neurons has increased in complexity and revealed a fine-tuned regulation of their activity dynamics across the whole sequence of feeding-related behaviours. This review focuses on recent studies that refined and re-evaluated our understanding of the regulatory principles and behavioural effects of AgRP circuits. We aim to cover major discoveries on the dynamic regulation of AgRP neuronal activity by exteroceptive and interoceptive food-related cues, their pleiotropic effects in feeding and whole-body homeostasis, and the associated AgRP circuits. The function and regulation of AgRP neuron will be sequentially discussed across the temporal series of behavioural and physiological changes occurring during the appetitive (food craving and foraging), the anticipatory (discovery of food-predicting cues), and the consummatory/post-ingestive phase of feeding (calorie ingestion).
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Affiliation(s)
- Ayden Gouveia
- Max Planck Institute for Metabolism Research, Max Planck Research Group Neurocircuit Wiring and Function, Cologne, Germany.,Cologne Excellence Cluster for Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Rui de Oliveira Beleza
- Max Planck Institute for Metabolism Research, Max Planck Research Group Neurocircuit Wiring and Function, Cologne, Germany.,Cologne Excellence Cluster for Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Sophie M Steculorum
- Max Planck Institute for Metabolism Research, Max Planck Research Group Neurocircuit Wiring and Function, Cologne, Germany.,Cologne Excellence Cluster for Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
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26
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Gong T, Hashimoto AC, Sasuclark AR, Khadka VS, Gurary A, Pitts MW. Selenoprotein M Promotes Hypothalamic Leptin Signaling and Thioredoxin Antioxidant Activity. Antioxid Redox Signal 2021; 35:775-787. [PMID: 30648404 PMCID: PMC8617589 DOI: 10.1089/ars.2018.7594] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Aims: Selenoproteins are an essential class of proteins involved in redox signaling and energy metabolism. However, the functions of many selenoproteins are not clearly established. Selenoprotein M (SELENOM), an endoplasmic reticulum (ER)-resident oxidoreductase bearing structural similarity to thioredoxin (TXN), is among those yet to be fully characterized. This protein is highly expressed in hypothalamic regions involved in leptin signaling and has been previously linked to energy metabolism. Herein, we performed a series of studies using in vivo and in vitro models to probe the specific influence of SELENOM on hypothalamic leptin signaling and assess SELENOM-regulated pathways. Innovation and Results: Our initial experiment in vivo demonstrated that (i) leptin promotes hypothalamic expression of SELENOM and (ii) leptin-induced STAT3 phosphorylation is impeded by SELENOM deficiency. Additional in vitro studies using mHypoE-44 immortalized hypothalamic neurons corroborated these findings, as SELENOM deficiency obstructed downstream STAT3 phosphorylation and cytosolic calcium responses evoked by leptin treatment. Correspondingly, SELENOM overexpression enhanced leptin sensitivity. Microarray analysis conducted in parallel on hypothalamic tissue and mHypoE-44 cells revealed multiple genes significantly affected by SELENOM deficiency, including thioredoxin interacting protein, a negative regulator of the TXN system. Further analysis determined that (i) SELENOM itself possesses intrinsic TXN activity and (ii) SELENOM deficiency leads to a reduction in overall TXN activity. Finally, mHypoE-44 cells lacking SELENOM displayed diminished activation of the nuclear factor kappa-light-chain enhancer of activated B-cells (NF-κB) signaling pathway and increased susceptibility to ER stress-mediated cell death. Conclusion: In sum, these findings establish SELENOM as a positive regulator of leptin signaling and TXN antioxidant activity in the hypothalamus. Antioxid. Redox Signal. 35, 775-787.
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Affiliation(s)
- Ting Gong
- Department of Molecular Biosciences and Bioengineering, University of Hawaii, Honolulu, Hawaii, USA
| | - Ann C Hashimoto
- Department of Cell and Molecular Biology, Medical Microbiolgy, and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Alexandru R Sasuclark
- Department of Cell and Molecular Biology, Medical Microbiolgy, and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Vedbar S Khadka
- Bioinformatics Core in the Department of Complementary and Integrative Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Alexandra Gurary
- Department of Tropical Medicine, Medical Microbiolgy, and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Matthew W Pitts
- Department of Cell and Molecular Biology, Medical Microbiolgy, and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
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Perissinotti PP, Martínez-Hernández E, He Y, Koob MD, Piedras-Rentería ES. Genetic Deletion of KLHL1 Leads to Hyperexcitability in Hypothalamic POMC Neurons and Lack of Electrical Responses to Leptin. Front Neurosci 2021; 15:718464. [PMID: 34566565 PMCID: PMC8458657 DOI: 10.3389/fnins.2021.718464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/05/2021] [Indexed: 11/13/2022] Open
Abstract
Kelch-like 1 (KLHL1) is a neuronal actin-binding protein that modulates voltage-gated calcium channels. The KLHL1 knockout (KO) model displays altered calcium channel expression in various brain regions. We analyzed the electrical behavior of hypothalamic POMC (proopiomelanocortin) neurons and their response to leptin. Leptin's effects on POMC neurons include enhanced gene expression, activation of the ERK1/2 pathway and increased electrical excitability. The latter is initiated by activation of the Jak2-PI3K-PLC pathway, which activates TRPC1/5 (Transient Receptor Potential Cation) channels that in turn recruit T-type channel activity resulting in increased excitability. Here we report over-expression of CaV3.1 T-type channels in the hypothalamus of KLHL1 KO mice increased T-type current density and enhanced POMC neuron basal excitability, rendering them electrically unresponsive to leptin. Electrical sensitivity to leptin was restored by partial blockade of T-type channels. The overexpression of hypothalamic T-type channels in POMC neurons may partially contribute to the obese and abnormal feeding phenotypes observed in KLHL1 KO mice.
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Affiliation(s)
- Paula P Perissinotti
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Elizabeth Martínez-Hernández
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Yungui He
- Institute for Translational Neuroscience and Department of Lab Medicine & Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Michael D Koob
- Institute for Translational Neuroscience and Department of Lab Medicine & Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Erika S Piedras-Rentería
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
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Perissinotti PP, Martínez-Hernández E, Piedras-Rentería ES. TRPC1/5-Ca V 3 Complex Mediates Leptin-Induced Excitability in Hypothalamic Neurons. Front Neurosci 2021; 15:679078. [PMID: 34177455 PMCID: PMC8226082 DOI: 10.3389/fnins.2021.679078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/30/2021] [Indexed: 12/17/2022] Open
Abstract
Leptin regulates hypothalamic POMC+ (pro-opiomelanocortin) neurons by inducing TRPC (Transient Receptor Potential Cation) channel-mediate membrane depolarization. The role of TRPC channels in POMC neuron excitability is clearly established; however, it remains unknown whether their activity alone is sufficient to trigger excitability. Here we show that the right-shift voltage induced by the leptin-induced TRPC channel-mediated depolarization of the resting membrane potential brings T-type channels into the active window current range, resulting in an increase of the steady state T-type calcium current from 40 to 70% resulting in increased intrinsic excitability of POMC neurons. We assessed the role and timing of T-type channels on excitability and leptin-induced depolarization in vitro in cultured mouse POMC neurons. The involvement of TRPC channels in the leptin-induced excitability of POMC neurons was corroborated by using the TRPC channel inhibitor 2APB, which precluded the effect of leptin. We demonstrate T-type currents are indispensable for both processes, as treatment with NNC-55-0396 prevented the membrane depolarization and rheobase changes induced by leptin. Furthermore, co-immunoprecipitation experiments suggest that TRPC1/5 channels and CaV3.1 and CaV3.2 channels co-exist in complex. The functional relevance of this complex was corroborated using intracellular Ca2+ chelators; intracellular BAPTA (but not EGTA) application was sufficient to preclude POMC neuron excitability. However, leptin-induced depolarization still occurred in the presence of either BAPTA or EGTA suggesting that the calcium entry necessary to self-activate the TRPC1/5 complex is not blocked by the presence of BAPTA in hypothalamic neurons. Our study establishes T-type channels as integral part of the signaling cascade induced by leptin, modulating POMC neuron excitability. Leptin activation of TRPC channels existing in a macromolecular complex with T-type channels recruits the latter by locally induced membrane depolarization, further depolarizing POMC neurons, triggering action potentials and excitability.
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Affiliation(s)
- Paula P Perissinotti
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Elizabeth Martínez-Hernández
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Erika S Piedras-Rentería
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
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29
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Stincic TL, Rønnekleiv OK, Kelly MJ. Membrane and nuclear initiated estrogenic regulation of homeostasis. Steroids 2021; 168:108428. [PMID: 31229508 PMCID: PMC6923613 DOI: 10.1016/j.steroids.2019.108428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/08/2019] [Accepted: 06/18/2019] [Indexed: 11/23/2022]
Abstract
Reproduction and energy balance are inextricably linked in order to optimize the evolutionary fitness of an organism. With insufficient or excessive energy stores a female is liable to suffer complications during pregnancy and produce unhealthy or obesity-prone offspring. The quintessential function of the hypothalamus is to act as a bridge between the endocrine and nervous systems, coordinating fertility and autonomic functions. Across the female reproductive cycle various motivations wax and wane, following levels of ovarian hormones. Estrogens, more specifically 17β-estradiol (E2), coordinate a triumvirate of hypothalamic neurons within the arcuate nucleus (ARH) that govern the physiological underpinnings of these behavioral dynamics. Arising from a common progenitor pool of cells, this triumvirate is composed of the kisspeptin (Kiss1ARH), proopiomelanocortin (POMC), and neuropeptide Y/agouti-related peptide (AgRP) neurons. Although the excitability of these neuronal subpopulations is subject to genomic and rapid estrogenic regulation, kisspeptin neurons are the most sensitive, reflecting their integral function in female fertility. Based on the premise that E2 coordinates autonomic functions around reproduction, we will review the recent findings on the synaptic interactions between Kiss1, AgRP and POMC neurons and how the rapid membrane-initiated and intracellular signaling cascades activated by E2 in these neurons are critical for control of homeostatic functions supporting reproduction.
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Affiliation(s)
- Todd L Stincic
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239, United States
| | - Oline K Rønnekleiv
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239, United States; Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, United States
| | - Martin J Kelly
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239, United States; Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, United States.
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30
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Abstract
We set out to identify novel neuronal populations controlling feeding behaviors. Therefore, we focused on identifying novel neuronal populations modulating food intake and body weight. In this article, we report that DMHPpp1r17 neurons are activated by increased food intake and that activating them results in decreased food intake and body weight, while inhibiting them leads to increased body weight and food intake. These data suggest that DMHPpp1r17 neurons restrict binges of eating. In addition to its basic science importance, these findings could have therapeutic applications, as they suggest that pharmacologic activation of PPP1R17 neurons could potentially reduce weight in settings of obesity and binge-like eating. Leptin-deficient ob/ob mice eat voraciously, and their food intake is markedly reduced by leptin treatment. In order to identify potentially novel sites of leptin action, we used PhosphoTRAP to molecularly profile leptin-responsive neurons in the hypothalamus and brainstem. In addition to identifying several known leptin responsive populations, we found that neurons in the dorsomedial hypothalamus (DMH) of ob/ob mice expressing protein phosphatase 1 regulatory subunit 17 (PPP1R17) constitutively express cFos and that this is suppressed by leptin treatment. Because ob mice are hyperphagic, we hypothesized that activating PPP1R17 neurons would increase food intake. However, chemogenetic activation of PPP1R17 neurons decreased food intake and body weight of ob/ob mice while inhibition of PPP1R17 neurons increased them. Similarly, in a scheduled feeding protocol that elicits increased consumption, mice also ate more when PPP1R17 neurons were inhibited and ate less when they were activated. Finally, we found that pair-feeding of ob mice reduced cFos expression to a similar extent as leptin and that reducing the amount of food available during scheduled feeding in DMHPpp1r17 neurons also decreased cFos in DMHPpp1r17 neurons. Finally, these neurons do not express the leptin receptor, suggesting that the effect of leptin on these neurons is indirect and secondary to reduced food intake. In aggregate, these results show that PPP1R17 neurons in the DMH are activated by increased food intake and in turn restrict intake to limit overconsumption, suggesting that they function to constrain binges of eating.
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31
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Gan L, Sun J, Yang S, Zhang X, Chen W, Sun Y, Wu X, Cheng C, Yuan J, Li A, Corbett MA, Dixon MP, Thomas T, Voss AK, Gécz J, Wang GZ, Bonni A, Li Q, Huang J. Chromatin-Binding Protein PHF6 Regulates Activity-Dependent Transcriptional Networks to Promote Hunger Response. Cell Rep 2021; 30:3717-3728.e6. [PMID: 32187544 DOI: 10.1016/j.celrep.2020.02.085] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/22/2019] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
Understanding the mechanisms of activity-dependent gene transcription underlying adaptive behaviors is challenging at neuronal-subtype resolution. Using cell-type specific molecular analysis in agouti-related peptide (AgRP) neurons, we reveal that the profound hunger-induced transcriptional changes greatly depend on plant homeodomain finger protein 6 (PHF6), a transcriptional repressor enriched in AgRP neurons. Loss of PHF6 in the satiated mice results in a hunger-state-shifting transcriptional profile, while hunger fails to further induce a rapid and robust activity-dependent gene transcription in PHF6-deficient AgRP neurons. We reveal that PHF6 binds to the promoters of a subset of immediate-early genes (IEGs) and that this chromatin binding is dynamically regulated by hunger state. Depletion of PHF6 decreases hunger-driven feeding motivation and makes the mice resistant to body weight gain under repetitive fasting-refeeding conditions. Our work identifies a neuronal subtype-specific transcriptional repressor that modulates transcriptional profiles in different nutritional states and enables adaptive eating behavior.
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Affiliation(s)
- Linhua Gan
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jingjing Sun
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Shuo Yang
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaocui Zhang
- Core Facility of Basic Medical Sciences, Basic Medicine Faculty of Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wu Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Yiyu Sun
- Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201999, China
| | - Xiaohua Wu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Cheng Cheng
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jing Yuan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; HUST-Suzhou Institute for Brainmatics, Suzhou 215125, China
| | - Anan Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; HUST-Suzhou Institute for Brainmatics, Suzhou 215125, China
| | - Mark A Corbett
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - Mathew P Dixon
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Tim Thomas
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, VIC, Australia
| | - Anne K Voss
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, VIC, Australia
| | - Jozef Gécz
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - Guang-Zhong Wang
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai 200031, China
| | - Azad Bonni
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Qian Li
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China.
| | - Ju Huang
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China.
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32
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Guillaumin MCC, Burdakov D. Neuropeptides as Primary Mediators of Brain Circuit Connectivity. Front Neurosci 2021; 15:644313. [PMID: 33776641 PMCID: PMC7991401 DOI: 10.3389/fnins.2021.644313] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 02/18/2021] [Indexed: 11/21/2022] Open
Abstract
Across sleep and wakefulness, brain function requires inter-neuronal interactions lasting beyond seconds. Yet, most studies of neural circuit connectivity focus on millisecond-scale interactions mediated by the classic fast transmitters, GABA and glutamate. In contrast, neural circuit roles of the largest transmitter family in the brain–the slow-acting peptide transmitters–remain relatively overlooked, or described as “modulatory.” Neuropeptides may efficiently implement sustained neural circuit connectivity, since they are not rapidly removed from the extracellular space, and their prolonged action does not require continuous presynaptic firing. From this perspective, we review actions of evolutionarily-conserved neuropeptides made by brain-wide-projecting hypothalamic neurons, focusing on lateral hypothalamus (LH) neuropeptides essential for stable consciousness: the orexins/hypocretins. Action potential-dependent orexin release inside and outside the hypothalamus evokes slow postsynaptic excitation. This excitation does not arise from modulation of classic neurotransmission, but involves direct action of orexins on their specific G-protein coupled receptors (GPCRs) coupled to ion channels. While millisecond-scale, GABA/glutamate connectivity within the LH may not be strong, re-assessing LH microcircuits from the peptidergic viewpoint is consistent with slow local microcircuits. The sustained actions of neuropeptides on neuronal membrane potential may enable core brain functions, such as temporal integration and the creation of lasting permissive signals that act as “eligibility traces” for context-dependent information routing and plasticity. The slowness of neuropeptides has unique advantages for efficient neuronal processing and feedback control of consciousness.
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Affiliation(s)
| | - Denis Burdakov
- Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
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Gastelum C, Perez L, Hernandez J, Le N, Vahrson I, Sayers S, Wagner EJ. Adaptive Changes in the Central Control of Energy Homeostasis Occur in Response to Variations in Energy Status. Int J Mol Sci 2021; 22:2728. [PMID: 33800452 PMCID: PMC7962960 DOI: 10.3390/ijms22052728] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/15/2022] Open
Abstract
Energy homeostasis is regulated in coordinate fashion by the brain-gut axis, the homeostatic energy balance circuitry in the hypothalamus and the hedonic energy balance circuitry comprising the mesolimbcortical A10 dopamine pathway. Collectively, these systems convey and integrate information regarding nutrient status and the rewarding properties of ingested food, and formulate it into a behavioral response that attempts to balance fluctuations in consumption and food-seeking behavior. In this review we start with a functional overview of the homeostatic and hedonic energy balance circuitries; identifying the salient neural, hormonal and humoral components involved. We then delve into how the function of these circuits differs in males and females. Finally, we turn our attention to the ever-emerging roles of nociceptin/orphanin FQ (N/OFQ) and pituitary adenylate cyclase-activating polypeptide (PACAP)-two neuropeptides that have garnered increased recognition for their regulatory impact in energy homeostasis-to further probe how the imposed regulation of energy balance circuitry by these peptides is affected by sex and altered under positive (e.g., obesity) and negative (e.g., fasting) energy balance states. It is hoped that this work will impart a newfound appreciation for the intricate regulatory processes that govern energy homeostasis, as well as how recent insights into the N/OFQ and PACAP systems can be leveraged in the treatment of conditions ranging from obesity to anorexia.
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Affiliation(s)
- Cassandra Gastelum
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (C.G.); (L.P.); (J.H.); (N.L.); (I.V.); (S.S.)
| | - Lynnea Perez
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (C.G.); (L.P.); (J.H.); (N.L.); (I.V.); (S.S.)
| | - Jennifer Hernandez
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (C.G.); (L.P.); (J.H.); (N.L.); (I.V.); (S.S.)
| | - Nikki Le
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (C.G.); (L.P.); (J.H.); (N.L.); (I.V.); (S.S.)
| | - Isabella Vahrson
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (C.G.); (L.P.); (J.H.); (N.L.); (I.V.); (S.S.)
| | - Sarah Sayers
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (C.G.); (L.P.); (J.H.); (N.L.); (I.V.); (S.S.)
| | - Edward J. Wagner
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (C.G.); (L.P.); (J.H.); (N.L.); (I.V.); (S.S.)
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
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Chronic unpredictable stress induces depression-related behaviors by suppressing AgRP neuron activity. Mol Psychiatry 2021; 26:2299-2315. [PMID: 33432188 PMCID: PMC8272726 DOI: 10.1038/s41380-020-01004-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 02/06/2023]
Abstract
Previous studies have shown that AgRP neurons in the arcuate nucleus (ARC) respond to energy deficits and play a key role in the control of feeding behavior and metabolism. Here, we demonstrate that chronic unpredictable stress, an animal model of depression, decreases spontaneous firing rates, increases firing irregularity and alters the firing properties of AgRP neurons in both male and female mice. These changes are associated with enhanced inhibitory synaptic transmission and reduced intrinsic neuronal excitability. Chemogenetic inhibition of AgRP neurons increases susceptibility to subthreshold unpredictable stress. Conversely, chemogenetic activation of AgRP neurons completely reverses anhedonic and despair behaviors induced by chronic unpredictable stress. These results indicate that chronic stress induces maladaptive synaptic and intrinsic plasticity, leading to hypoactivity of AgRP neurons and subsequently causing behavioral changes. Our findings suggest that AgRP neurons in the ARC are a key component of neural circuitry involved in mediating depression-related behaviors and that increasing AgRP neuronal activity coule be a novel and effective treatment for depression.
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35
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Abstract
Twenty-two years after their discovery, the hypocretins (Hcrts), also known as orexins, are two of the most studied peptidergic systems, involved in myriad physiological systems that range from sleep, arousal, motivation, homeostatic regulation, fear, anxiety and learning. A causal relationship between activity of Hcrt and arousal stability was established shortly after their discovery and have led to the development of a new class of drugs to treat insomnia. In this review we discuss the many faces of the Hcrt system and examine recent findings that implicate decreased Hcrt function in the pathogenesis of a number of neuropsychiatric conditions. We also discuss future therapeutic strategies to replace or enhance Hcrt function as a treatment option for these neuropsychiatric conditions.
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Affiliation(s)
- Erica Seigneur
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
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Hwang YT, Piguet O, Hodges JR, Grunstein R, Burrell JR. Sleep and orexin: A new paradigm for understanding behavioural-variant frontotemporal dementia? Sleep Med Rev 2020; 54:101361. [DOI: 10.1016/j.smrv.2020.101361] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/12/2020] [Accepted: 05/15/2020] [Indexed: 12/14/2022]
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Tian JL, Gomeshtapeh FI. Potential Roles of O-GlcNAcylation in Primary Cilia- Mediated Energy Metabolism. Biomolecules 2020; 10:biom10111504. [PMID: 33139642 PMCID: PMC7693894 DOI: 10.3390/biom10111504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 12/26/2022] Open
Abstract
The primary cilium, an antenna-like structure on most eukaryotic cells, functions in transducing extracellular signals into intracellular responses via the receptors and ion channels distributed along it membrane. Dysfunction of this organelle causes an array of human diseases, known as ciliopathies, that often feature obesity and diabetes; this indicates the primary cilia's active role in energy metabolism, which it controls mainly through hypothalamic neurons, preadipocytes, and pancreatic β-cells. The nutrient sensor, O-GlcNAc, is widely involved in the regulation of energy homeostasis. Not only does O-GlcNAc regulate ciliary length, but it also modifies many components of cilia-mediated metabolic signaling pathways. Therefore, it is likely that O-GlcNAcylation (OGN) plays an important role in regulating energy homeostasis in primary cilia. Abnormal OGN, as seen in cases of obesity and diabetes, may play an important role in primary cilia dysfunction mediated by these pathologies.
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Affiliation(s)
- Jie L. Tian
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
- Correspondence: ; Tel.: +1-706-583-5551
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A Leptin-Mediated Neural Mechanism Linking Breathing to Metabolism. Cell Rep 2020; 33:108358. [PMID: 33176139 DOI: 10.1016/j.celrep.2020.108358] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/27/2020] [Accepted: 10/16/2020] [Indexed: 01/10/2023] Open
Abstract
Breathing is coupled to metabolism. Leptin, a peptide mainly secreted in proportion to adipose tissue mass, increases energy expenditure with a parallel increase in breathing. We demonstrate that optogenetic activation of LepRb neurons in the nucleus of the solitary tract (NTS) mimics the respiratory stimulation after systemic leptin administration. We show that leptin activates the sodium leak channel (NALCN), thereby depolarizing a subset of glutamatergic (VGluT2) LepRb NTS neurons expressing galanin. Mice with selective deletion of NALCN in LepRb neurons have increased breathing irregularity and central apneas. On a high-fat diet, these mice gain weight with an associated depression of minute ventilation and tidal volume, which are not detected in control littermates. Anatomical mapping reveals LepRb NTS-originating glutamatergic axon terminals in a brainstem inspiratory premotor region (rVRG) and dorsomedial hypothalamus. These findings directly link a defined subset of NTS LepRb cells to the matching of ventilation to energy balance.
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Ren Z, Liu Y, Hong W, Pan X, Gong P, Liu Q, Zhou G, Qin S. Conditional knockout of leptin receptor in neural stem cells leads to obesity in mice and affects neuronal differentiation in the hypothalamus early after birth. Mol Brain 2020; 13:109. [PMID: 32746867 PMCID: PMC7398062 DOI: 10.1186/s13041-020-00647-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/15/2020] [Indexed: 12/12/2022] Open
Abstract
Leptin, secreted by peripheral adipocytes, binds the leptin receptor (Lepr) in the hypothalamus, thereby contributing to the regulation of satiety and body weight. Lepr is expressed in the embryonic brain as early as embryonic day 12.5. However, the function of Lepr in neural precursor cells in the brain has not been resolved. To address this issue, we crossed the Leprflox/flox mice with each of Shh-Cre mice (Shh, sonic hedgehog) and Nestin (Nes)-Cre mice. We found that deletion of Lepr specifically in nestin-expressing cells led to extreme obesity, but the conditional null of Lepr in Shh-expressing cells had no obvious phenotype. Moreover, the level of leptin-activated pSTAT3 decreased in the anterior and central subregions of the arcuate hypothalamus of Shh-Cre; Leprflox/flox mice compared with the controls. By contrast, in Nes-Cre; Leprflox/flox mice, the level of leptin-activated pSTAT3 decreased in all subregions including the anterior, central, and posterior arcuate hypothalamus as well as the dorsomedial, ventromedial, and median eminence of the hypothalamus, revealing that the extensive lack of Lepr in the differentiated neurons of the hypothalamus in the conditional null mice. Notably, conditional deletion of Lepr in nestin-expressing cells enhanced the differentiation of neural precursor cells into neurons and oligodendroglia but inhibited differentiation into astrocytes early in postnatal development of hypothalamus. Our results suggest that Lepr expression in neural precursor cells is essential for maintaining normal body weight as well as the differentiation of neural precursor cells to the neural/glial fate in the hypothalamus shortly after birth.
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Affiliation(s)
- Zhonggan Ren
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Yitong Liu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Wentong Hong
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Xinjie Pan
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Pifang Gong
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Qiong Liu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, China;, Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai, 200032, China
| | - Guomin Zhou
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, China;, Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai, 200032, China
| | - Song Qin
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, China;, Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai, 200032, China.
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Cara AL, Myers MG, Elias CF. Lack of AR in LepRb Cells Disrupts Ambulatory Activity and Neuroendocrine Axes in a Sex-Specific Manner in Mice. Endocrinology 2020; 161:bqaa110. [PMID: 32609838 PMCID: PMC7383963 DOI: 10.1210/endocr/bqaa110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/26/2020] [Indexed: 11/19/2022]
Abstract
Disorders of androgen imbalance, such as hyperandrogenism in females or hypoandrogenism in males, increase risk of visceral adiposity, type 2 diabetes, and infertility. Androgens act upon androgen receptors (AR) which are expressed in many tissues. In the brain, AR are abundant in hypothalamic nuclei involved in regulation of reproduction and energy homeostasis, yet the role of androgens acting via AR in specific neuronal populations has not been fully elucidated. Leptin receptor (LepRb)-expressing neurons coexpress AR predominantly in hypothalamic arcuate and ventral premammillary nuclei (ARH and PMv, respectively), with low colocalization in other LepRb neuronal populations, and very low colocalization in the pituitary gland and gonads. Deletion of AR from LepRb-expressing cells (LepRbΔAR) has no effect on body weight, energy expenditure, and glucose homeostasis in male and female mice. However, LepRbΔAR female mice show increased body length later in life, whereas male LepRbΔAR mice show an increase in spontaneous ambulatory activity. LepRbΔAR mice display typical pubertal timing, estrous cycles, and fertility, but increased testosterone levels in males. Removal of sex steroid negative feedback action induced an exaggerated rise in luteinizing hormone in LepRbΔAR males and follicle-stimulating hormone in LepRbΔAR females. Our findings show that AR can directly affect a subset of ARH and PMv neurons in a sex-specific manner and demonstrate specific androgenic actions in the neuroendocrine hypothalamus.
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Affiliation(s)
- Alexandra L Cara
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Martin G Myers
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Carol F Elias
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
- Department of Obstetrics and Gynaecology, University of Michigan, Ann Arbor, Michigan
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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: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [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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Beutler LR, Corpuz TV, Ahn JS, Kosar S, Song W, Chen Y, Knight ZA. Obesity causes selective and long-lasting desensitization of AgRP neurons to dietary fat. eLife 2020; 9:e55909. [PMID: 32720646 PMCID: PMC7398661 DOI: 10.7554/elife.55909] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/20/2020] [Indexed: 12/12/2022] Open
Abstract
Body weight is regulated by interoceptive neural circuits that track energy need, but how the activity of these circuits is altered in obesity remains poorly understood. Here we describe the in vivo dynamics of hunger-promoting AgRP neurons during the development of diet-induced obesity in mice. We show that high-fat diet attenuates the response of AgRP neurons to an array of nutritionally-relevant stimuli including food cues, intragastric nutrients, cholecystokinin and ghrelin. These alterations are specific to dietary fat but not carbohydrate or protein. Subsequent weight loss restores the responsiveness of AgRP neurons to exterosensory cues but fails to rescue their sensitivity to gastrointestinal hormones or nutrients. These findings reveal that obesity triggers broad dysregulation of hypothalamic hunger neurons that is incompletely reversed by weight loss and may contribute to the difficulty of maintaining a reduced weight.
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Affiliation(s)
| | | | - Jamie S Ahn
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Seher Kosar
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Weimin Song
- Northwestern University Feinberg School of Medicine, Comprehensive Metabolic CoreChicagoUnited States
| | - Yiming Chen
- UCSF Department of PhysiologySan FranciscoUnited States
- UCSF Neuroscience Graduate ProgramSan FranciscoUnited States
| | - Zachary A Knight
- Howard Hughes Medical InstituteChevy ChaseUnited States
- UCSF Department of PhysiologySan FranciscoUnited States
- UCSF Neuroscience Graduate ProgramSan FranciscoUnited States
- Kavli Institute for Fundamental NeuroscienceSan FranciscoUnited States
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Effects of metabolic state on the regulation of melanocortin circuits. Physiol Behav 2020; 224:113039. [PMID: 32610101 PMCID: PMC7387173 DOI: 10.1016/j.physbeh.2020.113039] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 06/01/2020] [Accepted: 06/26/2020] [Indexed: 12/14/2022]
Abstract
Dysfunction in neurophysiological systems that regulate food intake and metabolism are at least partly responsible for obesity and related comorbidities. An important component of this process is the hypothalamic melanocortin system, where an imbalance can result in severe obesity and deficits in glucose metabolism. Exercise offers many health benefits related to cardiovascular improvements, hunger control, and blood glucose homeostasis. However, the molecular mechanism underlying the exercise-induced improvements to the melanocortin system remain undefined. Here, we review the role of the melanocortin system to sense hormonal, nutrient, and neuronal signals of energy status. This information is then relayed onto secondary neurons in order to regulate physiological parameters, which promote proper energy and glucose balance. We also provide an overview on the effects of physical exercise to induce biophysical changes in the melanocortin circuit which may regulate food intake, glucose metabolism and improve overall metabolic health.
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Neuropeptide Y Expression Defines a Novel Class of GABAergic Projection Neuron in the Inferior Colliculus. J Neurosci 2020; 40:4685-4699. [PMID: 32376782 DOI: 10.1523/jneurosci.0420-20.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 04/22/2020] [Accepted: 05/01/2020] [Indexed: 12/24/2022] Open
Abstract
Located in the midbrain, the inferior colliculus (IC) integrates information from numerous auditory nuclei and is an important hub for sound processing. Despite its importance, little is known about the molecular identity and functional roles of defined neuron types in the IC. Using a multifaceted approach in mice of both sexes, we found that neuropeptide Y (NPY) expression identifies a major class of inhibitory neurons, accounting for approximately one-third of GABAergic neurons in the IC. Retrograde tracing showed that NPY neurons are principal neurons that can project to the medial geniculate nucleus. In brain slice recordings, many NPY neurons fired spontaneously, suggesting that NPY neurons may drive tonic inhibition onto postsynaptic targets. Morphologic reconstructions showed that NPY neurons are stellate cells, and the dendrites of NPY neurons in the tonotopically organized central nucleus of the IC cross isofrequency laminae. Immunostaining confirmed that NPY neurons express NPY, and we therefore hypothesized that NPY signaling regulates activity in the IC. In crosses between Npy1rcre and Ai14 Cre-reporter mice, we found that NPY Y1 receptor (Y1R)-expressing neurons are glutamatergic and were broadly distributed throughout the rostrocaudal extent of the IC. In whole-cell recordings, application of a high-affinity Y1R agonist led to hyperpolarization in most Y1R-expressing IC neurons. Thus, NPY neurons represent a novel class of inhibitory principal neurons that are well poised to use GABAergic and NPY signaling to regulate the excitability of circuits in the IC and auditory thalamus.SIGNIFICANCE STATEMENT The identification of neuron types is a fundamental question in neuroscience. In the inferior colliculus (IC), the hub of the central auditory pathway, molecular markers for distinct classes of inhibitory neurons have remained unknown. We found that neuropeptide Y (NPY) expression identifies a class of GABAergic principal neurons that constitute one-third of the inhibitory neurons in the IC. NPY neurons fire spontaneously, have a stellate morphology, and project to the auditory thalamus. Additionally, we found that NPY signaling hyperpolarized the membrane potential of a subset of excitatory IC neurons that express the NPY Y1 receptor. Thus, NPY neurons are a novel class of inhibitory neurons that use GABA and NPY signaling to regulate activity in the IC and auditory thalamus.
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Cowen N, Bhatnagar A. The Potential Role of Activating the ATP-Sensitive Potassium Channel in the Treatment of Hyperphagic Obesity. Genes (Basel) 2020; 11:genes11040450. [PMID: 32326226 PMCID: PMC7230375 DOI: 10.3390/genes11040450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/16/2020] [Indexed: 02/06/2023] Open
Abstract
To evaluate the potential role of ATP-sensitive potassium (KATP) channel activation in the treatment of hyperphagic obesity, a PubMed search was conducted focused on the expression of genes encoding the KATP channel, the response to activating the KATP channel in tissues regulating appetite and the establishment and maintenance of obesity, the evaluation of KATP activators in obese hyperphagic animal models, and clinical studies on syndromic obesity. KATP channel activation is mechanistically involved in the regulation of appetite in the arcuate nucleus; the regulation of hyperinsulinemia, glycemic control, appetite and satiety in the dorsal motor nucleus of vagus; insulin secretion by β-cells; and the synthesis and β-oxidation of fatty acids in adipocytes. KATP channel activators have been evaluated in hyperphagic obese animal models and were shown to reduce hyperphagia, induce fat loss and weight loss in older animals, reduce the accumulation of excess body fat in growing animals, reduce circulating and hepatic lipids, and improve glycemic control. Recent experience with a KATP channel activator in Prader-Willi syndrome is consistent with the therapeutic responses observed in animal models. KATP channel activation, given the breadth of impact and animal model and clinical results, is a viable target in hyperphagic obesity.
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Jais A, Paeger L, Sotelo-Hitschfeld T, Bremser S, Prinzensteiner M, Klemm P, Mykytiuk V, Widdershooven PJM, Vesting AJ, Grzelka K, Minère M, Cremer AL, Xu J, Korotkova T, Lowell BB, Zeilhofer HU, Backes H, Fenselau H, Wunderlich FT, Kloppenburg P, Brüning JC. PNOC ARC Neurons Promote Hyperphagia and Obesity upon High-Fat-Diet Feeding. Neuron 2020; 106:1009-1025.e10. [PMID: 32302532 PMCID: PMC7303947 DOI: 10.1016/j.neuron.2020.03.022] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/11/2020] [Accepted: 03/23/2020] [Indexed: 12/30/2022]
Abstract
Calorie-rich diets induce hyperphagia and promote obesity, although the underlying mechanisms remain poorly defined. We find that short-term high-fat-diet (HFD) feeding of mice activates prepronociceptin (PNOC)-expressing neurons in the arcuate nucleus of the hypothalamus (ARC). PNOCARC neurons represent a previously unrecognized GABAergic population of ARC neurons distinct from well-defined feeding regulatory AgRP or POMC neurons. PNOCARC neurons arborize densely in the ARC and provide inhibitory synaptic input to nearby anorexigenic POMC neurons. Optogenetic activation of PNOCARC neurons in the ARC and their projections to the bed nucleus of the stria terminalis promotes feeding. Selective ablation of these cells promotes the activation of POMC neurons upon HFD exposure, reduces feeding, and protects from obesity, but it does not affect food intake or body weight under normal chow consumption. We characterize PNOCARC neurons as a novel ARC neuron population activated upon palatable food consumption to promote hyperphagia. Acute high-fat-diet feeding activates PNOC neurons in the arcuate nucleus (ARC) GABAergic PNOCARC neurons inhibit anorexigenic POMC neurons Optogenetic activation of PNOCARC neurons promotes feeding Ablation of PNOCARC neurons protects from obesity
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Affiliation(s)
- Alexander Jais
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Lars Paeger
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Institute for Zoology, Biocenter, University of Cologne, Cologne, Germany
| | - Tamara Sotelo-Hitschfeld
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Stephan Bremser
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Institute for Zoology, Biocenter, University of Cologne, Cologne, Germany
| | - Melanie Prinzensteiner
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Paul Klemm
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Vasyl Mykytiuk
- Neuronal Circuits and Behaviour Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Pia J M Widdershooven
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Anna Juliane Vesting
- Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Obesity and Cancer Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Katarzyna Grzelka
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Marielle Minère
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Anna Lena Cremer
- Multimodal Imaging of Brain Metabolism Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Jie Xu
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Tatiana Korotkova
- Neuronal Circuits and Behaviour Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Bradford B Lowell
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02215, USA
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland; Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, 8093 Zurich, Switzerland
| | - Heiko Backes
- Multimodal Imaging of Brain Metabolism Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Henning Fenselau
- Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - F Thomas Wunderlich
- Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Obesity and Cancer Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Peter Kloppenburg
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Institute for Zoology, Biocenter, University of Cologne, Cologne, Germany.
| | - Jens C Brüning
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
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Abstract
Food intake and energy homeostasis determine survival of the organism and species. Information on total energy levels and metabolic state are sensed in the periphery and transmitted to the brain, where it is integrated and triggers the animal to forage, prey, and consume food. Investigating circuitry and cellular mechanisms coordinating energy balance and feeding behaviors has drawn on many state-of-the-art techniques, including gene manipulation, optogenetics, virus tracing, and single-cell sequencing. These new findings provide novel insights into how the central nervous system regulates food intake, and shed the light on potential therapeutic interventions for eating-related disorders such as obesity and anorexia.
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Abstract
Neuroimmunology and immunometabolism are burgeoning topics of study, but the intersection of these two fields is scarcely considered. This interplay is particularly prevalent within adipose tissue, where immune cells and the sympathetic nervous system (SNS) have an important role in metabolic homeostasis and pathology, namely in obesity. In the present Review, we first outline the established reciprocal adipose-SNS relationship comprising the neuroendocrine loop facilitated primarily by adipose tissue-derived leptin and SNS-derived noradrenaline. Next, we review the extensive crosstalk between adipocytes and resident innate immune cells as well as the changes that occur in these secretory and signalling pathways in obesity. Finally, we discuss the effect of SNS adrenergic signalling in immune cells and conclude with exciting new research demonstrating an immutable role for SNS-resident macrophages in modulating SNS-adipose crosstalk. We posit that the latter point constitutes the existence of a new field - neuroimmunometabolism.
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Affiliation(s)
- Chelsea M Larabee
- Department of Physiology, Anatomy & Genetics, Oxford University, Oxford, UK
| | - Oliver C Neely
- Department of Physiology, Anatomy & Genetics, Oxford University, Oxford, UK
| | - Ana I Domingos
- Department of Physiology, Anatomy & Genetics, Oxford University, Oxford, UK.
- The Howard Hughes Medical Institute (HHMI), New York, NY, USA.
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Cabral A, Fernandez G, Tolosa MJ, Rey Moggia Á, Calfa G, De Francesco PN, Perello M. Fasting induces remodeling of the orexigenic projections from the arcuate nucleus to the hypothalamic paraventricular nucleus, in a growth hormone secretagogue receptor-dependent manner. Mol Metab 2019; 32:69-84. [PMID: 32029231 PMCID: PMC7005150 DOI: 10.1016/j.molmet.2019.11.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/14/2019] [Accepted: 11/20/2019] [Indexed: 02/06/2023] Open
Abstract
Objective Arcuate nucleus (ARC) neurons producing Agouti-related peptide (AgRP) and neuropeptide Y (NPY; ARCAgRP/NPY neurons) are activated under energy-deficit states. ARCAgRP/NPY neurons innervate the hypothalamic paraventricular nucleus (PVH), and ARC→PVH projections are recognized as key regulators of food intake. Plasma ghrelin levels increase under energy-deficit states and activate ARCAgRP/NPY neurons by acting on the growth hormone secretagogue receptor (GHSR). Here, we hypothesized that activation of ARCAgRP/NPY neurons in fasted mice would promote morphological remodeling of the ARCAgRP/NPY→PVH projections in a GHSR-dependent manner. Methods We performed 1) fluorescent immunohistochemistry, 2) imaging of green fluorescent protein (GFP) signal in NPY-GFP mice, and 3) DiI axonal labeling in brains of ad libitum fed or fasted mice with pharmacological or genetic blockage of the GHSR signaling and then estimated the density and strength of ARCAgRP/NPY→PVH fibers by assessing the mean fluorescence intensity, the absolute area with fluorescent signal, and the intensity of the fluorescent signal in the fluorescent area of the PVH. Results We found that 1) the density and strength of ARCAgRP/NPY fibers increase in the PVH of fasted mice, 2) the morphological remodeling of the ARCAgRP/NPY→PVH projections correlates with the activation of PVH neurons, and 3) PVH neurons are not activated in ARC-ablated mice. We also found that fasting-induced remodeling of ARCAgRP/NPY→PVH fibers and PVH activation are impaired in mice with pharmacological or genetic blockage of GHSR signaling. Conclusion This evidence shows that the connectivity between hypothalamic circuits controlling food intake can be remodeled in the adult brain, depending on the energy balance conditions, and that GHSR activity is a key regulator of this phenomenon. The density and strength of ARCAgRP/NPY→PVH fibers increase in fasted mice. Remodeling of ARCAgRP/NPY→PVH projections correlates with the activation of PVH neurons. GHSR signaling is required for fasting-induced ARCAgRP/NPY→PVH projection remodeling.
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Affiliation(s)
- Agustina Cabral
- Laboratorio de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional La Plata y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Buenos Aires, Argentina
| | - Gimena Fernandez
- Laboratorio de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional La Plata y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Buenos Aires, Argentina
| | - María J Tolosa
- Laboratorio de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional La Plata y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Buenos Aires, Argentina
| | - Ángeles Rey Moggia
- Laboratorio de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional La Plata y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Buenos Aires, Argentina
| | - Gastón Calfa
- Instituto de Farmacología Experimental de Córdoba (IFEC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Pablo N De Francesco
- Laboratorio de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional La Plata y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Buenos Aires, Argentina
| | - Mario Perello
- Laboratorio de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional La Plata y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Buenos Aires, Argentina.
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González-García I, Milbank E, Martinez-Ordoñez A, Diéguez C, López M, Contreras C. HYPOTHesizing about central comBAT against obesity. J Physiol Biochem 2019; 76:193-211. [PMID: 31845114 DOI: 10.1007/s13105-019-00719-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 12/02/2019] [Indexed: 12/12/2022]
Abstract
The hypothalamus is a brain region in charge of many vital functions. Among them, BAT thermogenesis represents an essential physiological function to maintain body temperature. In the metabolic context, it has now been established that energy expenditure attributed to BAT function can contribute to the energy balance in a substantial extent. Thus, therapeutic interest in this regard has increased in the last years and some studies have shown that BAT function in humans can make a real contribution to improve diabetes and obesity-associated diseases. Nevertheless, how the hypothalamus controls BAT activity is still not fully understood. Despite the fact that much has been known about the mechanisms that regulate BAT activity in recent years, and that the central regulation of thermogenesis offers a very promising target, many questions remain still unsolved. Among them, the possible human application of knowledge obtained from rodent studies, and drug administration strategies able to specifically target the hypothalamus. Here, we review the current knowledge of homeostatic regulation of BAT, including the molecular insights of brown adipocytes, its central control, and its implication in the development of obesity.
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Affiliation(s)
- Ismael González-García
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.
| | - Edward Milbank
- CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Anxo Martinez-Ordoñez
- CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
| | - Carlos Diéguez
- CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Miguel López
- CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Cristina Contreras
- Department of Physiology, Pharmacy School, Complutense University of Madrid, 28040, Madrid, Spain.
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