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Rojo D, Hael CE, Soria A, de Souza FSJ, Low MJ, Franchini LF, Rubinstein M. A mammalian tripartite enhancer cluster controls hypothalamic Pomc expression, food intake, and body weight. Proc Natl Acad Sci U S A 2024; 121:e2322692121. [PMID: 38652744 PMCID: PMC11067048 DOI: 10.1073/pnas.2322692121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/12/2024] [Indexed: 04/25/2024] Open
Abstract
Food intake and energy balance are tightly regulated by a group of hypothalamic arcuate neurons expressing the proopiomelanocortin (POMC) gene. In mammals, arcuate-specific POMC expression is driven by two cis-acting transcriptional enhancers known as nPE1 and nPE2. Because mutant mice lacking these two enhancers still showed hypothalamic Pomc mRNA, we searched for additional elements contributing to arcuate Pomc expression. By combining molecular evolution with reporter gene expression in transgenic zebrafish and mice, here, we identified a mammalian arcuate-specific Pomc enhancer that we named nPE3, carrying several binding sites also present in nPE1 and nPE2 for transcription factors known to activate neuronal Pomc expression, such as ISL1, NKX2.1, and ERα. We found that nPE3 originated in the lineage leading to placental mammals and remained under purifying selection in all mammalian orders, although it was lost in Simiiformes (monkeys, apes, and humans) following a unique segmental deletion event. Interestingly, ablation of nPE3 from the mouse genome led to a drastic reduction (>70%) in hypothalamic Pomc mRNA during development and only moderate (<33%) in adult mice. Comparison between double (nPE1 and nPE2) and triple (nPE1, nPE2, and nPE3) enhancer mutants revealed the relative contribution of nPE3 to hypothalamic Pomc expression and its importance in the control of food intake and adiposity in male and female mice. Altogether, these results demonstrate that nPE3 integrates a tripartite cluster of partially redundant enhancers that originated upon a triple convergent evolutionary process in mammals and that is critical for hypothalamic Pomc expression and body weight homeostasis.
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Affiliation(s)
- Daniela Rojo
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires1428, Argentina
| | - Clara E. Hael
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires1428, Argentina
| | - Agustina Soria
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires1428, Argentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires1428, Argentina
| | - Flávio S. J. de Souza
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires1428, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires1428, Argentina
| | - Malcolm J. Low
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI48105
| | - Lucía F. Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires1428, Argentina
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires1428, Argentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires1428, Argentina
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI48105
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Chhabra KH, Bathina S, Faniyan TS, Samuel DJ, Raza MU, de Souza Cordeiro LM, Viana Di Prisco G, Atwood BK, Robles J, Bainbridge L, Davis A. ADGRL1 is a glucose receptor involved in mediating energy and glucose homeostasis. Diabetologia 2024; 67:170-189. [PMID: 37712955 PMCID: PMC10709246 DOI: 10.1007/s00125-023-06010-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/07/2023] [Indexed: 09/16/2023]
Abstract
AIMS/HYPOTHESIS The brain is a major consumer of glucose as an energy source and regulates systemic glucose as well as energy balance. Although glucose transporters such as GLUT2 and sodium-glucose cotransporter 2 (SGLT2) are known to regulate glucose homeostasis and metabolism, the identity of a receptor that binds glucose to activate glucose signalling pathways in the brain is unknown. In this study, we aimed to discover a glucose receptor in the mouse hypothalamus. METHODS Here we used a high molecular mass glucose-biotin polymer to enrich glucose-bound mouse hypothalamic neurons through cell-based affinity chromatography. We then subjected the enriched neurons to proteomic analyses and identified adhesion G-protein coupled receptor 1 (ADGRL1) as a top candidate for a glucose receptor. We validated glucose-ADGRL1 interactions using CHO cells stably expressing human ADGRL1 and ligand-receptor binding assays. We generated and determined the phenotype of global Adgrl1-knockout mice and hypothalamus-specific Adgrl1-deficient mice. We measured the variables related to glucose and energy homeostasis in these mice. We also generated an Adgrl1Cre mouse model to investigate the role of ADGRL1 in sensing glucose using electrophysiology. RESULTS Adgrl1 is highly expressed in the ventromedial nucleus of the hypothalamus (VMH) in mice. Lack of Adgrl1 in the VMH in mice caused fasting hyperinsulinaemia, enhanced glucose-stimulated insulin secretion and insulin resistance. In addition, the Adgrl1-deficient mice had impaired feeding responses to glucose and fasting coupled with abnormal glucose sensing and decreased physical activity before development of obesity and hyperglycaemia. In female mice, ovariectomy was necessary to reveal the contribution of ADGRL1 to energy and glucose homeostasis. CONCLUSIONS/INTERPRETATION Altogether, our findings demonstrate that ADGRL1 binds glucose and is involved in energy as well as glucose homeostasis in a sex-dependent manner. Targeting ADGRL1 may introduce a new class of drugs for the treatment of type 2 diabetes and obesity.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA.
| | - Siresha Bathina
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Tumininu S Faniyan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Dennis J Samuel
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Muhammad Ummear Raza
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Leticia Maria de Souza Cordeiro
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Gonzalo Viana Di Prisco
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brady K Atwood
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jorge Robles
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Lauren Bainbridge
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Autumn Davis
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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Ji Y, Liu D, Zhu H, Bao L, Chang R, Gao X, Yin J. Unstructured Polypeptides as a Versatile Drug Delivery Technology. Acta Biomater 2023; 164:74-93. [PMID: 37075961 DOI: 10.1016/j.actbio.2023.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/23/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
Although polyethylene glycol (PEG), or "PEGylation" has become a widely applied approach for improving the efficiency of drug delivery, the immunogenicity and non-biodegradability of this synthetic polymer have prompted an evident need for alternatives. To overcome these caveats and to mimic PEG -or other natural or synthetic polymers- for the purpose of drug half-life extension, unstructured polypeptides are designed. Due to their tunable length, biodegradability, low immunogenicity and easy production, unstructured polypeptides have the potential to replace PEG as the preferred technology for therapeutic protein/peptide delivery. This review provides an overview of the evolution of unstructured polypeptides, starting from natural polypeptides to engineered polypeptides and discusses their characteristics. Then, it is described that unstructured polypeptides have been successfully applied to numerous drugs, including peptides, proteins, antibody fragments, and nanocarriers, for half-life extension. Innovative applications of unstructured peptides as releasable masks, multimolecular adaptors and intracellular delivery carriers are also discussed. Finally, challenges and future perspectives of this promising field are briefly presented. STATEMENT OF SIGNIFICANCE: : Polypeptide fusion technology simulating PEGylation has become an important topic for the development of long-circulating peptide or protein drugs without reduced activity, complex processes, and kidney injury caused by PEG modification. Here we provide a detailed and in-depth review of the recent advances in unstructured polypeptides. In addition to the application of enhanced pharmacokinetic performance, emphasis is placed on polypeptides as scaffolders for the delivery of multiple drugs, and on the preparation of reasonably designed polypeptides to manipulate the performance of proteins and peptides. This review will provide insight into future application of polypeptides in peptide or protein drug development and the design of novel functional polypeptides.
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Affiliation(s)
- Yue Ji
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Dingkang Liu
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Haichao Zhu
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Lichen Bao
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing 210009, China
| | - Ruilong Chang
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Xiangdong Gao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China.
| | - Jun Yin
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China.
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Surbhi, Wittmann G, Low MJ, Lechan RM. Adult-born proopiomelanocortin neurons derived from Rax-expressing precursors mitigate the metabolic effects of congenital hypothalamic proopiomelanocortin deficiency. Mol Metab 2021; 53:101312. [PMID: 34329773 PMCID: PMC8383116 DOI: 10.1016/j.molmet.2021.101312] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/12/2021] [Accepted: 07/25/2021] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE Proopiomelanocortin (POMC) neurons of the hypothalamic arcuate nucleus are essential regulators of energy balance. Selective loss of POMC production in these cells results in extreme obesity and metabolic comorbidities. Neurogenesis occurs in the adult hypothalamus, but it remains uncertain whether functional POMC neurons emerge in physiologically significant numbers during adulthood. Here, we tested whether Rax-expressing precursors generate POMC neurons in adult mice and rescue the metabolic phenotype caused by congenital hypothalamic POMC deficiency. METHODS Initially, we identified hypothalamic Rax-expressing cell types using wild-type and Rax-CreERT2:Ai34D mice. Then we generated compound Rax-CreERT2:ArcPomcloxTB/loxTB mice in which endogenous hypothalamic Pomc expression is silenced, but can be restored by tamoxifen administration selectively in neurons derived from Rax+ progenitors. The number of POMC neurons generated by Rax+ progenitors in adult mice and their axonal projections was determined. The metabolic effects of these neurons were assessed by measuring food intake, bodyweight, and body composition, along with glucose and insulin levels. RESULTS We found that Rax is expressed by tanycytes and a previously unrecognized cell type in the hypothalamic parenchyma of adult mice. Rax+ progenitors generated ~10% of the normal adult hypothalamic POMC neuron population within two weeks of tamoxifen treatment. The same rate and steady state of POMC neurogenesis persisted from young adult to aged mice. These new POMC neurons established terminal projections to brain regions that were involved in energy homeostasis. Mice with Rax+ progenitor-derived POMC neurons had reduced body fat mass, improved glucose tolerance, increased insulin sensitivity, and decreased bodyweight in proportion to the number of new POMC neurons. CONCLUSIONS These data demonstrate that Rax+ progenitors generate POMC neurons in sufficient numbers during adulthood to mitigate the metabolic abnormalities of hypothalamic POMC-deficient mice. The findings suggest that adult hypothalamic neurogenesis is a robust phenomenon in mice that can significantly impact energy homeostasis.
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Affiliation(s)
- Surbhi
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, 2800 Plymouth Rd, Ann Arbor, MI, 48109, USA.
| | - Gábor Wittmann
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA.
| | - Malcolm J Low
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, 2800 Plymouth Rd, Ann Arbor, MI, 48109, USA.
| | - Ronald M Lechan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA.
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Moura-Assis A, Nogueira PAS, de-Lima-Junior JC, Simabuco FM, Gaspar JM, Donato Jr J, Velloso LA. TLR4-interactor with leucine-rich repeats (TRIL) is involved in diet-induced hypothalamic inflammation. Sci Rep 2021; 11:18015. [PMID: 34504172 PMCID: PMC8429592 DOI: 10.1038/s41598-021-97291-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/23/2021] [Indexed: 02/08/2023] Open
Abstract
Obesity and high-fat diet (HFD) consumption result in hypothalamic inflammation and metabolic dysfunction. While the TLR4 activation by dietary fats is a well-characterized pathway involved in the neuronal and glial inflammation, the role of its accessory proteins in diet-induced hypothalamic inflammation remains unknown. Here, we demonstrate that the knockdown of TLR4-interactor with leucine-rich repeats (Tril), a functional component of TLR4, resulted in reduced hypothalamic inflammation, increased whole-body energy expenditure, improved the systemic glucose tolerance and protection from diet-induced obesity. The POMC-specific knockdown of Tril resulted in decreased body fat, decreased white adipose tissue inflammation and a trend toward increased leptin signaling in POMC neurons. Thus, Tril was identified as a new component of the complex mechanisms that promote hypothalamic dysfunction in experimental obesity and its inhibition in the hypothalamus may represent a novel target for obesity treatment.
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Affiliation(s)
- Alexandre Moura-Assis
- grid.411087.b0000 0001 0723 2494Laboratory of Cell Signalling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Pedro A. S. Nogueira
- grid.411087.b0000 0001 0723 2494Laboratory of Cell Signalling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Jose C. de-Lima-Junior
- grid.411087.b0000 0001 0723 2494Laboratory of Cell Signalling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Fernando M. Simabuco
- grid.411087.b0000 0001 0723 2494Multidisciplinary Laboratory of Food and Health (LABMAS), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira, São Paulo Brazil
| | - Joana M. Gaspar
- grid.411087.b0000 0001 0723 2494Laboratory of Cell Signalling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Jose Donato Jr
- grid.11899.380000 0004 1937 0722Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Licio A. Velloso
- grid.411087.b0000 0001 0723 2494Laboratory of Cell Signalling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil ,National Institute of Science and Technology on Neuroimmunomodulation, Rio de Janeiro, Brazil
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Iqbal NJ, Schwartz GJ, Zhao H, Zhu L, Chua S. Cyclin-dependent kinase 4/6 inhibitors require an arcuate-to-paraventricular hypothalamus melanocortin circuit to treat diet-induced obesity. Am J Physiol Endocrinol Metab 2021; 320:E467-E474. [PMID: 33356996 PMCID: PMC7988782 DOI: 10.1152/ajpendo.00386.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The arcuate nucleus (ARC) of the hypothalamus comprises two antagonistic neuron populations critical for energy balance, namely, the anorexigenic pro-opiomelanocortin (POMC) and the orexigenic agouti-related peptide (AgRP) neurons that act as agonists and antagonists, respectively, for neurons expressing the type IV melanocortin receptor (MC4R) (Andermann ML and Lowell BB. Neuron 95: 757-778, 2017). MC4R activation increases energy expenditure and decreases food intake during positive energy balance states to prevent diet-induced obesity (DIO). Work from our group identified aberrant neuronal cell cycle events both as a novel biomarker and druggable target in the ARC for the treatment of DIO, demonstrating pharmacological restoration of retinoblastoma protein function in the ARC using cyclin-dependent kinase 4/6 (CDK4/6) inhibitors could treat DIO in mice by increasing lipid oxidation to selectively decrease fat mass. However, the role of CDK4/6 inhibitors on food intake was not examined. Four-week-old Mc4r-loxTB mice were continuously administered high-fat diet (60% kcal fat). At 8 wk of age, animals were administered 60 mg/kg abemaciclib orally or a saline control and monitored every 2 wk for fat mass changes by MRI. At 11 wk of age, all animals were injected bilaterally in the paraventricular hypothalamus with AAV8 serotype virus expressing a Cre-mCherry and monitored for another 5 wk. Restoration of Mc4r expression in the paraventricular hypothalamic nucleus (PVN/PVH) reduced food intake in hyperphagic obese mice when given CDK4/6 inhibitor therapy. The reduced food intake was responsible for reduced fat mass in mice treated with abemaciclib. These results indicate that targeting POMC neurons could be an effective strategy in treating diet-related obesity.NEW & NOTEWORTHY We have defined some of the necessary components to prevent high-fat diet-induced obesity at the molecular and cellular level. Within POMC neurons, the retinoblastoma protein must remain active and prevented from phosphoinactivation by cyclin-dependent kinases. The downstream neurons within the PVH must also properly express MC4R for the circuit to appropriately regulate feeding behavior.
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Affiliation(s)
- Niloy Jafar Iqbal
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York
| | - Gary J Schwartz
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - Hongling Zhao
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York
| | - Liang Zhu
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York
| | - Streamson Chua
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
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Na ES, Lam DD, Yokosawa E, Adams JM, Olson DP, Low MJ. Decreased sensitivity to the anorectic effects of leptin in mice that lack a Pomc-specific neural enhancer. PLoS One 2021; 15:e0244793. [PMID: 33382813 PMCID: PMC7775064 DOI: 10.1371/journal.pone.0244793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/24/2020] [Indexed: 11/18/2022] Open
Abstract
Enhancer redundancy has been postulated to provide a buffer for gene expression against genetic and environmental perturbations. While work in Drosophila has identified functionally overlapping enhancers, work in mammalian models has been limited. Recently, we have identified two partially redundant enhancers, nPE1 and nPE2, that drive proopiomelanocortin gene expression in the hypothalamus. Here we demonstrate that deletion of nPE1 produces mild obesity while knockout of nPE2 has no discernible metabolic phenotypes. Additionally, we show that acute leptin administration has significant effects on nPE1 knockout mice, with food intake and body weight change significantly impacted by peripheral leptin treatment. nPE1 knockout mice became less responsive to leptin treatment over time as percent body weight change increased over 2 week exposure to peripheral leptin. Both Pomc and Agrp mRNA were not differentially affected by chronic leptin treatment however we did see a decrease in Pomc and Agrp mRNA in both nPE1 and nPE2 knockout calorie restricted mice as compared to calorie restricted PBS-treated WT mice. Collectively, these data suggest dynamic regulation of Pomc by nPE1 such that mice with nPE1 knockout become less responsive to the anorectic effects of leptin treatment over time. Our results also support our earlier findings in which nPE2 may only be critical in adult mice that lack nPE1, indicating that these neural enhancers work synergistically to influence metabolism.
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Affiliation(s)
- Elisa S. Na
- Department of Psychology & Philosophy Texas Woman’s University, Denton, Texas, United States of America
- * E-mail: (ESN); (DDL)
| | - Daniel D. Lam
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Chair of Neurogenetics, Neurological Clinic and Polyclinic, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
- * E-mail: (ESN); (DDL)
| | - Eva Yokosawa
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jessica M. Adams
- Division of Endocrinology, Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - David P. Olson
- Division of Endocrinology, Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Malcolm J. Low
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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Mendoza-Herrera K, Florio AA, Moore M, Marrero A, Tamez M, Bhupathiraju SN, Mattei J. The Leptin System and Diet: A Mini Review of the Current Evidence. Front Endocrinol (Lausanne) 2021; 12:749050. [PMID: 34899599 PMCID: PMC8651558 DOI: 10.3389/fendo.2021.749050] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/29/2021] [Indexed: 01/02/2023] Open
Abstract
Leptin promotes satiety and modulates energy balance and weight. Diet-induced obesity leads to leptin resistance, exacerbating overeating. We reviewed the literature on the relationship between diet and leptin, which suggests that addressing leptin resistance through dietary interventions can contribute counteracting obesity. Albeit some limitations (e.g., limited rigor, small samples sizes), studies in animals and humans show that diets high in fat, carbohydrates, fructose, and sucrose, and low in protein are drivers of leptin resistance. Despite methodological heterogeneity pertaining to this body of literature, experimental studies show that energy-restricted diets can reduce leptinemia both in the short and long term and potentially reverse leptin resistance in humans. We also discuss limitations of this evidence, future lines of research, and implications for clinical and public health translations. Main limitations include the lack of a single universally-accepted definition of leptin resistance, and of adequate ways to accurately measure it in humans. The use of leptin sensitizers (drugs) and genetically individualized diets are alternatives against leptin resistance that should be further researched in humans. The tested very-low-energy intervention diets are challenging to translate into wide clinical or population recommendations. In conclusion, the link between nutritional components and leptin resistance, as well as research indicating that this condition is reversible, emphasizes the potential of diet to recover sensitivity to this hormone. A harmonized definition of leptin resistance, reliable methods to measure it, and large-scale, translational, clinical, and precision nutrition research involving rigorous methods are needed to benefit populations through these approaches.
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de Souza Cordeiro LM, Elsheikh A, Devisetty N, Morgan DA, Ebert SN, Rahmouni K, Chhabra KH. Hypothalamic MC4R regulates glucose homeostasis through adrenaline-mediated control of glucose reabsorption via renal GLUT2 in mice. Diabetologia 2021; 64:181-194. [PMID: 33052459 PMCID: PMC7718429 DOI: 10.1007/s00125-020-05289-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/18/2020] [Indexed: 12/12/2022]
Abstract
AIMS/HYPOTHESIS Melanocortin 4 receptor (MC4R) mutation is the most common cause of known monogenic obesity in humans. Unexpectedly, humans and rodents with MC4R deficiency do not develop hyperglycaemia despite chronic obesity and insulin resistance. To explain the underlying mechanisms for this phenotype, we determined the role of MC4R in glucose homeostasis in the presence and absence of obesity in mice. METHODS We used global and hypothalamus-specific MC4R-deficient mice to investigate the brain regions that contribute to glucose homeostasis via MC4R. We performed oral, intraperitoneal and intravenous glucose tolerance tests in MC4R-deficient mice that were either obese or weight-matched to their littermate controls to define the role of MC4R in glucose regulation independently of changes in body weight. To identify the integrative pathways through which MC4R regulates glucose homeostasis, we measured renal and adrenal sympathetic nerve activity. We also evaluated glucose homeostasis in adrenaline (epinephrine)-deficient mice to investigate the role of adrenaline in mediating the effects of MC4R in glucose homeostasis. We employed a graded [13C6]glucose infusion procedure to quantify renal glucose reabsorption in MC4R-deficient mice. Finally, we measured the levels of renal glucose transporters in hypothalamus-specific MC4R-deficient mice and adrenaline-deficient mice using western blotting to ascertain the molecular mechanisms underlying MC4R control of glucose homeostasis. RESULTS We found that obese and weight-matched MC4R-deficient mice exhibited improved glucose tolerance due to elevated glucosuria, not enhanced beta cell function. Moreover, MC4R deficiency selectively in the paraventricular nucleus of the hypothalamus (PVH) is responsible for reducing the renal threshold for glucose as measured by graded [13C6]glucose infusion technique. The MC4R deficiency suppressed renal sympathetic nerve activity by 50% in addition to decreasing circulating adrenaline and renal GLUT2 levels in mice, which contributed to the elevated glucosuria. We further report that adrenaline-deficient mice recapitulated the increased excretion of glucose in urine observed in the MC4R-deficient mice. Restoration of circulating adrenaline in both the MC4R- and adrenaline-deficient mice reversed their phenotype of improved glucose tolerance and elevated glucosuria, demonstrating the role of adrenaline in mediating the effects of MC4R on glucose reabsorption. CONCLUSIONS/INTERPRETATION These findings define a previously unrecognised function of hypothalamic MC4R in glucose reabsorption mediated by adrenaline and renal GLUT2. Taken together, our findings indicate that elevated glucosuria due to low sympathetic tone explains why MC4R deficiency does not cause hyperglycaemia despite inducing obesity and insulin resistance. Graphical abstract.
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Affiliation(s)
- Leticia Maria de Souza Cordeiro
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Arwa Elsheikh
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Nagavardhini Devisetty
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Donald A Morgan
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Steven N Ebert
- Division of Metabolic and Cardiovascular Sciences, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Kavaljit H Chhabra
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA.
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10
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Moreno-Fernandez J, Ochoa JJ, Lopez-Frias M, Diaz-Castro J. Impact of Early Nutrition, Physical Activity and Sleep on the Fetal Programming of Disease in the Pregnancy: A Narrative Review. Nutrients 2020; 12:nu12123900. [PMID: 33419354 PMCID: PMC7766505 DOI: 10.3390/nu12123900] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/13/2022] Open
Abstract
Early programming is the adaptation process by which nutrition and environmental factors alter development pathways during prenatal growth, inducing changes in postnatal metabolism and diseases. The aim of this narrative review, is evaluating the current knowledge in the scientific literature on the effects of nutrition, environmental factors, physical activity and sleep on development pathways. If in utero adaptations were incorrect, this would cause a mismatch between prenatal programming and adulthood. Adequate caloric intake, protein, mineral, vitamin, and long-chain fatty acids, have been noted for their relevance in the offspring brain functions and behavior. Fetus undernutrition/malnutrition causes a delay in growth and have detrimental effects on the development and subsequent functioning of the organs. Pregnancy is a particularly vulnerable period for the development of food preferences and for modifications in the emotional response. Maternal obesity increases the risk of developing perinatal complications and delivery by cesarean section and has long-term implications in the development of metabolic diseases. Physical exercise during pregnancy contributes to overall improved health post-partum. It is also interesting to highlight the relevance of sleep problems during pregnancy, which influence adequate growth and fetal development. Taking into account these considerations, we conclude that nutrition and metabolic factors during early life play a key role of health promotion and public health nutrition programs worldwide to improve the health of the offspring and the health costs of hospitalization.
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Affiliation(s)
- Jorge Moreno-Fernandez
- Department of Physiology, Faculty of Pharmacy, Campus Universitario de Cartuja, E-18071 Granada, Spain; (J.M.-F.); (M.L.-F.); (J.D.-C.)
- Institute of Nutrition and Food Technology “José Mataix Verdú”, University of Granada, E-18071 Granada, Spain
| | - Julio J. Ochoa
- Department of Physiology, Faculty of Pharmacy, Campus Universitario de Cartuja, E-18071 Granada, Spain; (J.M.-F.); (M.L.-F.); (J.D.-C.)
- Institute of Nutrition and Food Technology “José Mataix Verdú”, University of Granada, E-18071 Granada, Spain
- Correspondence: ; Tel.: +34-958-241-000 (ext. 20317)
| | - Magdalena Lopez-Frias
- Department of Physiology, Faculty of Pharmacy, Campus Universitario de Cartuja, E-18071 Granada, Spain; (J.M.-F.); (M.L.-F.); (J.D.-C.)
- Institute of Nutrition and Food Technology “José Mataix Verdú”, University of Granada, E-18071 Granada, Spain
| | - Javier Diaz-Castro
- Department of Physiology, Faculty of Pharmacy, Campus Universitario de Cartuja, E-18071 Granada, Spain; (J.M.-F.); (M.L.-F.); (J.D.-C.)
- Institute of Nutrition and Food Technology “José Mataix Verdú”, University of Granada, E-18071 Granada, Spain
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11
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Lieu L, Chau D, Afrin S, Dong Y, Alhadeff AL, Betley JN, Williams KW. Effects of metabolic state on the regulation of melanocortin circuits. Physiol Behav 2020; 224:113039. [PMID: 32610101 DOI: 10.1016/j.physbeh.2020.113039] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [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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12
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Hael CE, Rojo D, Orquera DP, Low MJ, Rubinstein M. The transcriptional regulator PRDM12 is critical for Pomc expression in the mouse hypothalamus and controlling food intake, adiposity, and body weight. Mol Metab 2020; 34:43-53. [PMID: 32180559 PMCID: PMC7011018 DOI: 10.1016/j.molmet.2020.01.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/04/2020] [Accepted: 01/07/2020] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Regulation of food intake and energy balance depends on a group of hypothalamic neurons that release anorexigenic melanocortins encoded by the Pomc gene. Although the physiological importance of central melanocortins is well appreciated, the genetic program that defines the functional identity of melanocortin neurons and assures high levels of hypothalamic Pomc expression is only beginning to be understood. This study assessed whether the transcriptional regulator PRDM12, identified as a highly expressed gene in adult mouse POMC neurons, plays an important role in the identity and function of melanocortin neurons. METHODS We first determined the cellular distribution of PRDM12 in the developing hypothalamus. Then we studied mutant mice with constitutively inactivated Prdm12 to evaluate possible changes in hypothalamic Pomc expression. In addition, we characterized conditional mutant mice specifically lacking Prdm12 in ISL1-positive or POMC neurons during development. Finally, we measured food intake, body weight progression up to 16 weeks of age, adiposity, and glucose tolerance in adult mice lacking Prdm12 selectively from POMC neurons. RESULTS PRDM12 co-expressed with POMC in mouse hypothalamic neurons from early development to adulthood. Mice lacking Prdm12 displayed greatly reduced Pomc expression in the developing hypothalamus. Selective ablation of Prdm12 from ISL1 neurons prevented hypothalamic Pomc expression. The conditional ablation of Prdm12 limited to POMC neurons greatly reduced Pomc expression in the developing hypothalamus and in adult mice led to increased food intake, adiposity, and obesity. CONCLUSIONS Altogether, our results demonstrate that PRDM12 plays an essential role in the early establishment of hypothalamic melanocortin neuron identity and the maintenance of high expression levels of Pomc. Its absence in adult mice greatly impairs Pomc expression and leads to increased food intake, adiposity, and obesity.
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Affiliation(s)
- Clara E Hael
- Institute of Investigations in Genetic Engineering and Molecular Biology, National Council of Scientific and Technological Research, 1428 Buenos Aires, Argentina
| | - Daniela Rojo
- Institute of Investigations in Genetic Engineering and Molecular Biology, National Council of Scientific and Technological Research, 1428 Buenos Aires, Argentina
| | - Daniela P Orquera
- Institute of Investigations in Genetic Engineering and Molecular Biology, National Council of Scientific and Technological Research, 1428 Buenos Aires, Argentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
| | - Marcelo Rubinstein
- Institute of Investigations in Genetic Engineering and Molecular Biology, National Council of Scientific and Technological Research, 1428 Buenos Aires, Argentina; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA; Department of Physiology, Molecular and Cellular Biology, School of Exact and Natural Sciences, University of Buenos Aires, 1428 Buenos Aires, Argentina.
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13
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Yu H, Chhabra KH, Thompson Z, Jones GL, Kiran S, Shangguan G, Low MJ. Hypothalamic POMC deficiency increases circulating adiponectin despite obesity. Mol Metab 2020; 35:100957. [PMID: 32244188 PMCID: PMC7082555 DOI: 10.1016/j.molmet.2020.01.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/22/2020] [Accepted: 01/31/2020] [Indexed: 02/06/2023] Open
Abstract
Objective The steep rise in the prevalence of obesity and its related metabolic syndrome have become a major worldwide health concerns. Melanocortin peptides from hypothalamic arcuate nucleus (Arc) POMC neurons induce satiety to limit food intake. Consequently, Arc Pomc-deficient mice (ArcPomc−/−) exhibit hyperphagia and obesity. Previous studies demonstrated that the circulating levels of adiponectin, a protein abundantly produced and secreted by fat cells, negatively correlate with obesity in both rodents and humans. However, we found that ArcPomc−/− mice have increased circulating adiponectin levels despite obesity. Therefore, we investigated the physiological function and underlying mechanisms of hypothalamic POMC in regulating systemic adiponectin levels. Methods Circulating adiponectin was measured in obese ArcPomc−/− mice at ages 4–52 weeks. To determine whether increased adiponectin was a direct result of ArcPomc deficiency or a secondary effect of obesity, we examined plasma adiponectin levels in calorie-restricted mice with or without a history of obesity and in ArcPomc−/− mice before and after genetic restoration of Pomc expression in the hypothalamus. To delineate the mechanisms causing increased adiponectin in ArcPomc−/− mice, we determined sympathetic outflow to adipose tissue by assessing epinephrine, norepinephrine, and tyrosine hydroxylase protein levels and measured the circulating adiponectin in the mice after acute norepinephrine or propranolol treatments. In addition, adiponectin mRNA and protein levels were measured in discrete adipose tissue depots to ascertain which fat depots contributed the most to the high level of adiponectin in the ArcPomc−/− mice. Finally, we generated compound Adiopoq−/−:ArcPomc−/− mice and compared their growth, body composition, and glucose homeostasis to the individual knockout mouse strains and their wild-type controls. Results Obese ArcPomc−/− female mice had unexpectedly increased plasma adiponectin compared to wild-type siblings at all ages greater than 8 weeks. Despite chronic calorie restriction to achieve normal body weights, higher adiponectin levels persisted in the ArcPomc−/− female mice. Genetic restoration of Pomc expression in the Arc or acute treatment of the ArcPomc−/− female mice with melanotan II reduced adiponectin levels to control littermate values. The ArcPomc−/− mice had defective thermogenesis and decreased epinephrine, norepinephrine, and tyrosine hydroxylase protein levels in their fat pads, indicating reduced sympathetic outflow to adipose tissue. Injections of norepinephrine into the ArcPomc−/− female mice reduced circulating adiponectin levels, whereas injections of propranolol significantly increased adiponectin levels. Despite the beneficial effects of adiponectin on metabolism, the deletion of adiponectin alleles in the ArcPomc−/− mice did not exacerbate their metabolic abnormalities. Conclusion In summary, to the best of our knowledge, this study provides the first evidence that despite obesity, the ArcPomc−/− mouse model has high circulating adiponectin levels, which demonstrated that increased fat mass is not necessarily correlated with hypoadiponectinemia. Our investigation also found a previously unknown physiological pathway connecting POMC neurons via the sympathetic nervous system to circulating adiponectin, thereby shedding light on the biological regulation of adiponectin. Obese female hypothalamic-specific Pomc-deficient mice have unexpectedly elevated circulating adiponectin. Restoration of Pomc expression in the hypothalamus reduces plasma adiponectin. Low sympathetic output to subcutaneous fat depots in the Pomc-deficient mice contributes to high adiponectin levels. Deletion of adiponectin in hypothalamic-specific Pomc-deficient mice does not alter their metabolic phenotype.
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Affiliation(s)
- Hui Yu
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA.
| | - Kavaljit H Chhabra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Zoe Thompson
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Graham L Jones
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Sylee Kiran
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; School of Literature, Science, and Arts, University of Michigan, Ann Arbor, MI, USA
| | - Gary Shangguan
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
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14
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Lopez‐Vicchi F, Ladyman SR, Ornstein AM, Gustafson P, Knowles P, Luque GM, Grattan DR, Becu‐Villalobos D. Chronic high prolactin levels impact on gene expression at discrete hypothalamic nuclei involved in food intake. FASEB J 2020; 34:3902-3914. [DOI: 10.1096/fj.201902357r] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/06/2019] [Accepted: 12/24/2019] [Indexed: 12/23/2022]
Affiliation(s)
- Felicitas Lopez‐Vicchi
- Instituto de Biología y Medicina Experimental Consejo Nacional de Investigaciones Científicas y Técnicas Buenos AiresArgentina
| | - Sharon R. Ladyman
- Centre for Neuroendocrinology, Department of Anatomy School of Biomedical Sciences University of Otago Dunedin New Zealand
- Maurice Wilkins Centre Auckland New Zealand
| | - Ana Maria Ornstein
- Instituto de Biología y Medicina Experimental Consejo Nacional de Investigaciones Científicas y Técnicas Buenos AiresArgentina
| | - Papillon Gustafson
- Centre for Neuroendocrinology, Department of Anatomy School of Biomedical Sciences University of Otago Dunedin New Zealand
| | - Penelope Knowles
- Centre for Neuroendocrinology, Department of Anatomy School of Biomedical Sciences University of Otago Dunedin New Zealand
| | - Guillermina Maria Luque
- Instituto de Biología y Medicina Experimental Consejo Nacional de Investigaciones Científicas y Técnicas Buenos AiresArgentina
| | - David R. Grattan
- Centre for Neuroendocrinology, Department of Anatomy School of Biomedical Sciences University of Otago Dunedin New Zealand
- Maurice Wilkins Centre Auckland New Zealand
| | - Damasia Becu‐Villalobos
- Instituto de Biología y Medicina Experimental Consejo Nacional de Investigaciones Científicas y Técnicas Buenos AiresArgentina
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15
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Contreras RE, Schriever SC, Pfluger PT. Physiological and Epigenetic Features of Yoyo Dieting and Weight Control. Front Genet 2019; 10:1015. [PMID: 31921275 PMCID: PMC6917653 DOI: 10.3389/fgene.2019.01015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Obesity and being overweight have become a worldwide epidemic affecting more than 1.9 billion adults and 340 million children. Efforts to curb this global health burden by developing effective long-term non-surgical weight loss interventions continue to fail due to weight regain after weight loss. Weight cycling, often referred to as Yoyo dieting, is driven by physiological counter-regulatory mechanisms that aim at preserving energy, i.e. decreased energy expenditure, increased energy intake, and impaired brain-periphery communication. Models based on genetically determined set points explained some of the weight control mechanisms, but exact molecular underpinnings remained elusive. Today, gene–environment interactions begin to emerge as likely drivers for the obesogenic memory effect associated with weight cycling. Here, epigenetic mechanisms, including histone modifications and DNA methylation, appear as likely factors that underpin long-lasting deleterious adaptations or an imprinted obesogenic memory to prevent weight loss maintenance. The first part summarizes our current knowledge on the physiology of weight cycling by discussing human and murine studies on the Yoyo-dieting phenomenon and physiological adaptations associated with weight loss and weight re-gain. The second part provides an overview on known associations between obesity and epigenetic modifications. We further interrogate the roles of epigenetic mechanisms in the CNS control of cognitive functions as well as reward and addictive behaviors, and subsequently discuss whether such mechanisms play a role in weight control. The final two parts describe major opportunities and challenges associated with studying epigenetic mechanisms in the CNS with its highly heterogenous cell populations, and provide a summary of recent technological advances that will help to delineate whether an obese memory is based upon epigenetic mechanisms.
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Affiliation(s)
- Raian E Contreras
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Centre for Diabetes Research (DZD), Neuherberg, Germany.,Neurobiology of Diabetes, TUM School of Medicine, Technische Universität München, Munich, Germany
| | - Sonja C Schriever
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Centre for Diabetes Research (DZD), Neuherberg, Germany
| | - Paul T Pfluger
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Centre for Diabetes Research (DZD), Neuherberg, Germany.,Neurobiology of Diabetes, TUM School of Medicine, Technische Universität München, Munich, Germany
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16
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Geary N. Control-theory models of body-weight regulation and body-weight-regulatory appetite. Appetite 2020; 144:104440. [PMID: 31494154 DOI: 10.1016/j.appet.2019.104440] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 08/08/2019] [Accepted: 09/02/2019] [Indexed: 12/24/2022]
Abstract
Human body weight (BW), or some variable related to it, is physiologically regulated. That is, negative feedback from changes in BW elicits compensatory influences on appetite, which may be called BW-regulatory appetite, and a component of energy expenditure (EE) called adaptive thermogenesis (AdEE). BW-regulatory appetite is of general significance because it appears to be related to a variety of aspects of human appetite beyond just energy intake. BW regulation, BW-regulatory appetite and AdEE are frequently discussed using concepts derived from control theory, which is the mathematical description of dynamic systems involving negative feedback. The aim of this review is to critically assess these discussions. Two general types of negative-feedback control have been invoked to describe BW regulation, set-point control and simple negative-feedback control, often called settling-point control in the BW literature. The distinguishing feature of set-point systems is the existence of an externally controlled target level of regulation, the set point. The performance of almost any negative-feedback regulatory system, however, can be modeled on the basis of feedback gain without including a set point. In both set-point and simple negative-feedback models of BW regulation, the precision of regulation is usually determined mainly by feedback gain, which refers to the transformations of feedback into compensatory changes in BW-regulatory appetite and AdEE. Stable BW most probably represents equilibria shaped by feedback gain and tonic open-loop challenges, especially obesogenic environments. Data indicate that simple negative-feedback control accurately models human BW regulation and that the set-point concept is superfluous unless its neuroendocrine representation is found in the brain. Additional research aimed at testing control-theory models in humans and non-human animals is warranted.
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Abstract
Leptin resistance refers to states in which leptin fails to promote its anticipated effects, frequently coexisting with hyperleptinaemia. Leptin resistance is closely associated with obesity and also observed in physiological situations such as pregnancy and in seasonal animals. Leptin resensitisation refers to the reversion of leptin-resistant states and is associated with improvement in endocrine and metabolic disturbances commonly observed in obesity and a sustained decrease of plasma leptin levels, possibly below a critical threshold level. In obesity, leptin resensitisation can be achieved with treatments that reduce body adiposity and leptinaemia, or with some pharmacological compounds, while physiological leptin resistance reverts spontaneously. The restoration of leptin sensitivity could be a useful strategy to treat obesity, maintain weight loss and/or reduce the recidivism rate for weight regain after dieting. This review provides an update and discussion about reversion of leptin-resistant states and modulation of the molecular mechanisms involved in each situation.
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Affiliation(s)
- María F Andreoli
- Laboratory of Experimental Neurodevelopment, Institute of Development and Paediatric Research (IDIP), La Plata Children's Hospital and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), La Plata, Buenos Aires, Argentina
- Argentine Research Council (CONICET), La Plata, Buenos Aires, Argentina
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Isin Cakir
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Mario Perello
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology (IMBICE, Argentine Research Council (CONICET), National University of La Plata and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)), La Plata, Buenos Aires, Argentina
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18
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Orquera DP, Tavella MB, de Souza FSJ, Nasif S, Low MJ, Rubinstein M. The Homeodomain Transcription Factor NKX2.1 Is Essential for the Early Specification of Melanocortin Neuron Identity and Activates Pomc Expression in the Developing Hypothalamus. J Neurosci 2019; 39:4023-35. [PMID: 30886014 DOI: 10.1523/JNEUROSCI.2924-18.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/03/2019] [Accepted: 03/08/2019] [Indexed: 12/14/2022] Open
Abstract
Food intake is tightly regulated by a group of neurons present in the arcuate nucleus of the hypothalamus, which release Pomc-encoded melanocortins, the absence of which induces marked hyperphagia and early-onset obesity. Although the relevance of hypothalamic POMC neurons in the regulation of body weight and energy balance is well appreciated, little is known about the transcription factors that establish the melanocortin neuron identity during brain development and its phenotypic maintenance in postnatal life. Here, we report that the transcription factor NKX2.1 is present in mouse hypothalamic POMC neurons from early development to adulthood. Electromobility shift assays showed that NKX2.1 binds in vitro to NKX binding motifs present in the neuronal Pomc enhancers nPE1 and nPE2 and chromatin immunoprecipitation assays detected in vivo binding of NKX2.1 to nPE1 and nPE2 in mouse hypothalamic extracts. Transgenic and mutant studies performed in mouse embryos of either sex and adult males showed that the NKX motifs present in nPE1 and nPE2 are essential for their transcriptional enhancer activity. The conditional early inactivation of Nkx2.1 in the ventral hypothalamus prevented the onset of Pomc expression. Selective Nkx2.1 ablation from POMC neurons decreased Pomc expression in adult males and mildly increased their body weight and adiposity. Our results demonstrate that NKX2.1 is necessary to activate Pomc expression by binding to conserved canonical NKX motifs present in nPE1 and nPE2. Therefore, NKX2.1 plays a critical role in the early establishment of hypothalamic melanocortin neuron identity and participates in the maintenance of Pomc expression levels during adulthood.SIGNIFICANCE STATEMENT Food intake and body weight regulation depend on hypothalamic neurons that release satiety-inducing neuropeptides, known as melanocortins. Central melanocortins are encoded byPomc, and Pomc mutations may lead to hyperphagia and severe obesity. Although the importance of central melanocortins is well appreciated, the genetic program that establishes and maintains fully functional POMC neurons remains to be explored. Here, we combined molecular, genetic, developmental, and functional studies that led to the discovery of NKX2.1, a transcription factor that participates in the early morphogenesis of the developing hypothalamus, as a key player in establishing the early identity of melanocortin neurons by activating Pomc expression. Thus, Nkx2.1 adds to the growing list of genes that participate in body weight regulation and adiposity.
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19
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Jones GL, Wittmann G, Yokosawa EB, Yu H, Mercer AJ, Lechan RM, Low MJ. Selective Restoration of Pomc Expression in Glutamatergic POMC Neurons: Evidence for a Dynamic Hypothalamic Neurotransmitter Network. eNeuro 2019; 6:ENEURO.0400-18.2019. [PMID: 30957016 PMCID: PMC6449166 DOI: 10.1523/eneuro.0400-18.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 02/15/2019] [Accepted: 02/17/2019] [Indexed: 01/19/2023] Open
Abstract
Hypothalamic POMC deficiency leads to obesity and metabolic deficiencies, largely due to the loss of melanocortin peptides. However, POMC neurons in the arcuate nucleus (ARC) are comprised of glutamatergic and GABAergic subpopulations. The developmental program, relative proportion and function of these two subpopulations are unresolved. To test whether glutamatergic POMC neurons serve a distinct role in maintaining energy homeostasis, we activated Pomc expression Cre- dependently in Vglut2-expressing neurons of mice with conditionally silenced Pomc alleles. The Vglut2-Pomc restored mice had normal ARC Pomc mRNA levels, POMC immunoreactivity, as well as body weight and body composition at age 12 weeks. Unexpectedly, the cumulative total of Vglut2+ glutamatergic- and Gad67+ GABAergic-Pomc neurons detected by in situ hybridization (ISH) exceeded 100% in both Vglut2- Pomc restored and control mice, indicating that a subpopulation of Pomc neurons must express both neuronal markers. Consistent with this hypothesis, triple ISH of C57BL/6J hypothalami revealed that 35% of ARC Pomc neurons were selectively Gad67+, 21% were selectively Vglut2+, and 38% expressed both Gad67 and Vglut2. The single Gad67+ and Vglut2+Pomc neurons were most prevalent in the rostral ARC, while the Vglut2/Gad67+ dual-phenotype cells predominated in the caudal ARC. A lineage trace using Ai9-tdTomato reporter mice to label fluorescently all Vglut2-expressing neurons showed equal numbers of tdTomato+ and tdTomato- POMC immunoreactive neurons. Together, these data suggest that POMC neurons exhibit developmental plasticity in their expression of glutamatergic and GABAergic markers, enabling re-establishment of normal energy homeostasis in the Vglut2-Pomc restored mice.
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Affiliation(s)
- Graham L. Jones
- Neuroscience Graduate Program
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Gábor Wittmann
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, MA 02111
| | - Eva B. Yokosawa
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Hui Yu
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Aaron J. Mercer
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Ronald M. Lechan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, MA 02111
| | - Malcolm J. Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
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20
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Chapelot D, Charlot K. Physiology of energy homeostasis: Models, actors, challenges and the glucoadipostatic loop. Metabolism 2019; 92:11-25. [PMID: 30500561 DOI: 10.1016/j.metabol.2018.11.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/25/2018] [Accepted: 11/19/2018] [Indexed: 12/16/2022]
Abstract
The aim of this review is to discuss the physiology of energy homeostasis (EH), which is a debated concept. Thus, we will see that the set-point theory is highly challenged and that other models integrating an anticipative component, such as energy allostasis, seem more relevant to experimental reports and life preservation. Moreover, the current obesity epidemic suggests that EH is poorly efficient in the modern human dietary environment. Non-homeostatic phenomena linked to hedonism and reward seem to profoundly impair EH. In this review, the apparent failed homeostatic responses to energy challenges such as exercise, cafeteria diet, overfeeding and diet-induced weight loss, as well as their putative determinants, are analyzed to highlight the mechanisms of EH. Then, the hormonal, neuronal, and metabolic factors of energy intake or energy expenditure are briefly presented. Last, this review focuses on the contributions of two of the most pivotal and often overlooked determinants of EH: the availability of endogenous energy and the pattern of energy intake. A glucoadipostatic loop model is finally proposed to link energy stored in adipose tissue to EH through changes in eating behavior via leptin and sympathetic nervous system activity.
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Affiliation(s)
- Didier Chapelot
- Université Paris 13, Centre de Recherche en Epidémiologie et Statistique, Equipe de Recherche en Epidémiologie Nutritionnelle (EREN), Inserm (U1153), Inra (U1125), Cnam, Bobigny, France.
| | - Keyne Charlot
- Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Brétigny-sur-Orge, France
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21
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Ramos-Lobo AM, Teixeira PD, Furigo IC, Melo HM, de M Lyra E Silva N, De Felice FG, Donato J. Long-term consequences of the absence of leptin signaling in early life. eLife 2019; 8:40970. [PMID: 30694175 PMCID: PMC6384028 DOI: 10.7554/elife.40970] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/28/2019] [Indexed: 12/11/2022] Open
Abstract
Leptin regulates energy balance and also exhibits neurotrophic effects during critical developmental periods. However, the actual role of leptin during development is not yet fully understood. To uncover the importance of leptin in early life, the present study restored leptin signaling either at the fourth or tenth week of age in mice formerly null for the leptin receptor (LepR) gene. We found that some defects previously considered irreversible due to neonatal deficiency of leptin signaling, including the poor development of arcuate nucleus neural projections, were recovered by LepR reactivation in adulthood. However, LepR deficiency in early life led to irreversible obesity via suppression of energy expenditure. LepR reactivation in adulthood also led to persistent reduction in hypothalamic Pomc, Cartpt and Prlh mRNA expression and to defects in the reproductive system and brain growth. Our findings revealed that early defects in leptin signaling cause permanent metabolic, neuroendocrine and developmental problems. Leptin is a hormone that keeps us healthy in many ways. It regulates our body weight by reining in our appetite and fine-tuning the energy we burn, and it helps us establish and maintain our fertility. It also participates in brain development. Leptin performs these roles by attaching to specific receptors in nerve cells and relaying relevant information to the brain. Early events can trigger life-long changes in the way our body works, a process called metabolic programming. Leptin is believed to participate in this reprogramming mechanism, but its role remains uncertain. In particular, it is still unclear which leptin-driven changes are permanent, and which ones are reversible. Being able to distinguish between the two types of alterations would help to better grasp the role leptin plays in early development. Here, Ramos-Lobo et al. examined genetically engineered mice born without a working leptin receptor. These animals were impervious to the effects of leptin. Then, once the rodents were adults, they were treated with a drug that restored their leptin receptors, making them sensitive to the hormone again. These experiments revealed that mice without leptin receptors during early life developed obesity, were less able to lose weight and burned less energy. Their reproductive success was also compromised. Finally, the lack of leptin during development caused permanent reduction of the animals’ brains, and changes in the activity of certain genes in the organ. The work by Ramos-Lobo et al. indicates that in mice, lacking leptin sensibility early in life conditions the body to permanently become ‘thrifty’, burning less energy and making it harder to lose weight. It is rare for humans to be born completely without leptin activity. Yet, having too much or too little food as a baby affects the level of the hormone, or our sensitivity to it: this may permanently change the way our bodies manage energy. Ultimately, learning more about these mechanisms could help us ward off or treat obesity.
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Affiliation(s)
- Angela M Ramos-Lobo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Pryscila Ds Teixeira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Isadora C Furigo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Helen M Melo
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Natalia de M Lyra E Silva
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Centre for Neuroscience Studies, Department of Psychiatry, Queen's University, Kingston, Canada
| | - Fernanda G De Felice
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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22
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Iqbal NJ, Lu Z, Liu SM, Schwartz GJ, Chua S, Zhu L. Cyclin-dependent kinase 4 is a preclinical target for diet-induced obesity. JCI Insight 2018; 3:123000. [PMID: 30185666 PMCID: PMC6171799 DOI: 10.1172/jci.insight.123000] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 07/26/2018] [Indexed: 12/12/2022] Open
Abstract
When obesity is caused by consumption of a high-fat diet, the tumor suppressor pRb is phosphoinactivated in the neurons of the mediobasal hypothalamus, a brain area critical for energy-balance regulation. However, the functional relevance of pRb phosphoinactivation in the mediobasal hypothalamus to diet-induced obesity remains unknown. Here, we show that inhibiting pRb phosphorylation in the mediobasal hypothalamus can prevent and treat diet-induced obesity in mice. Expressing an unphosphorylable pRb nonselectively in the mediobasal hypothalamus or conditionally in anorexigenic POMC neurons inhibits diet-induced obesity. Intracerebroventricular delivery of US Food and Drug Administration–approved (FDA-approved) cyclin-dependent kinase 4 (CDK4) inhibitor abemaciclib inhibits pRb phosphorylation in the mediobasal hypothalamus and prevents diet-induced obesity. Oral administration of abemaciclib at doses approved for human use reduces fat mass in diet-induced obese mice by increasing lipid oxidation without significantly reducing lean mass. With analysis of recent literature identifying CDK4 as the most abundantly expressed neuronal CDK in the mediobasal hypothalamus, our work uncovers CDK4 as the major kinase for hypothalamic pRb phosphoinactivation and a highly effective central antiobesity target. As three CDK4/6 inhibitors have recently received FDA approval for life-long breast cancer therapy, our study provides a preclinical basis for their expedient repurposing for obesity management. Inhibiting pRb phosphorylation in the mediobasal hypothalamus can prevent and treat diet-induced obesity in mice.
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Affiliation(s)
| | - Zhonglei Lu
- Department of Developmental and Molecular Biology and
| | - Shun Mei Liu
- Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA
| | - Gary J Schwartz
- Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA
| | - Streamson Chua
- Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA
| | - Liang Zhu
- Department of Developmental and Molecular Biology and.,Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA
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23
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Farias G, Netto BDM, Boritza KC, Bettini SC, Dâmaso AR, de Freitas ACT. Mechanisms of sustained long-term weight loss after RYGB: α-MSH is a key factor. Neuropeptides 2018; 69:60-65. [PMID: 29685637 DOI: 10.1016/j.npep.2018.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 03/09/2018] [Accepted: 04/12/2018] [Indexed: 02/07/2023]
Affiliation(s)
- Gisele Farias
- Surgical Clinic Post Graduate Program, Department of Surgery, Hospital de Clínicas - Universidade Federal do Paraná, UFPR, Surgical Clinic Post Graduate Program, Curitiba, PR, Brazil.
| | - Bárbara Dal Molin Netto
- Nutrition Post Graduate Program, Universidade Federal de São Paulo, Escola Paulista de Medicina, UNIFESP-EPM, Nutrition Post Graduate Program, São Paulo, SP, Brazil.
| | - Katia Cristina Boritza
- Biochemistry Section, Hospital de Clínicas, Universidade Federal do Paraná, UFPR, Curitiba, PR, Brazil
| | - Solange Cravo Bettini
- Gastrointestinal Surgery Service of Hospital de Clínicas, Universidade Federal do Paraná, UFPR, Curitiba, PR, Brazil
| | - Ana Raimunda Dâmaso
- Nutrition Post Graduate Program, Universidade Federal de São Paulo, Escola Paulista de Medicina, UNIFESP-EPM, Nutrition Post Graduate Program, São Paulo, SP, Brazil
| | - Alexandre Coutinho Teixeira de Freitas
- Surgical Clinic Post Graduate Program, Department of Surgery, Hospital de Clínicas - Universidade Federal do Paraná, UFPR, Surgical Clinic Post Graduate Program, Curitiba, PR, Brazil
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24
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Matikainen-Ankney BA, Kravitz AV. Persistent effects of obesity: a neuroplasticity hypothesis. Ann N Y Acad Sci 2018; 1428:221-239. [PMID: 29741270 DOI: 10.1111/nyas.13665] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/06/2018] [Accepted: 02/13/2018] [Indexed: 12/21/2022]
Abstract
The obesity epidemic is a leading cause of health problems in the United States, increasing the risk of cardiovascular, endocrine, and psychiatric diseases. Although many people lose weight through changes in diet and lifestyle, keeping the weight off remains a challenge. Here, we discuss a hypothesis that seeks to explain why obesity is so persistent. There is a great degree of overlap in the circuits implicated in substance use disorder and obesity, and neural plasticity of these circuits in response to drugs of abuse is well documented. We hypothesize that obesity is also associated with neural plasticity in these circuits, and this may underlie persistent changes in behavior, energy balance, and body weight. Here, we discuss how obesity-associated reductions in motivation and physical activity may be rooted in neurophysiological alterations in these circuits. Such plasticity may alter how humans and animals use, expend, and store energy, even after weight loss.
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Affiliation(s)
- Bridget A Matikainen-Ankney
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Alexxai V Kravitz
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland.,National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
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25
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Rubinstein M, Low MJ. Molecular and functional genetics of the proopiomelanocortin gene, food intake regulation and obesity. FEBS Lett 2017; 591:2593-2606. [PMID: 28771698 PMCID: PMC9975356 DOI: 10.1002/1873-3468.12776] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/31/2017] [Accepted: 07/31/2017] [Indexed: 12/20/2022]
Abstract
A specter is haunting the world, the specter of obesity. During the last decade, this pandemia has skyrocketed threatening children, adolescents and lower income families worldwide. Although driven by an increase in the consumption of ultraprocessed edibles of poor nutritional value, the obesogenic changes in contemporary human lifestyle affect people differently, revealing that some individuals are more prone to develop increased adiposity. During the last years, we performed a variety of genetic, evolutionary, biochemical and behavioral experiments that allowed us to understand how a group of neurons present in the arcuate nucleus of the hypothalamus regulate the expression of the proopiomelanocortin (Pomc) gene and induce satiety. We disentangled the neuronal transcriptional code of Pomc by identifying the cis-acting regulatory elements and primary transcription factors controlling hypothalamic Pomc expression and determined their functional importance in the regulation of food intake and adiposity. Altogether, our studies reviewed here shed light on the power and limitations of the mammalian central satiety pathways and may contribute to the development of individual and collective strategies to reduce the debilitating effects of the self-induced obesity pandemia.
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Affiliation(s)
- Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina,Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina,Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Malcolm J. Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA,Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
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26
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Chhabra KH, Morgan DA, Tooke BP, Adams JM, Rahmouni K, Low MJ. Reduced renal sympathetic nerve activity contributes to elevated glycosuria and improved glucose tolerance in hypothalamus-specific Pomc knockout mice. Mol Metab 2017; 6:1274-1285. [PMID: 29031726 PMCID: PMC5641634 DOI: 10.1016/j.molmet.2017.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/02/2017] [Accepted: 07/10/2017] [Indexed: 11/11/2022] Open
Abstract
Objective Hypothalamic arcuate nucleus-specific pro-opiomelanocortin deficient (ArcPomc−/−) mice exhibit improved glucose tolerance despite massive obesity and insulin resistance. We demonstrated previously that their improved glucose tolerance is due to elevated glycosuria. However, the underlying mechanisms that link glucose reabsorption in the kidney with ArcPomc remain unclear. Given the function of the hypothalamic melanocortin system in controlling sympathetic outflow, we hypothesized that reduced renal sympathetic nerve activity (RSNA) in ArcPomc−/− mice could explain their elevated glycosuria and consequent enhanced glucose tolerance. Methods We measured RSNA by multifiber recording directly from the nerves innervating the kidneys in ArcPomc−/− mice. To further validate the function of RSNA in glucose reabsorption, we denervated the kidneys of WT and diabetic db/db mice before measuring their glucose tolerance and urine glucose levels. Moreover, we performed western blot and immunohistochemistry to determine kidney GLUT2 and SGLT2 levels in either ArcPomc−/− mice or the renal-denervated mice. Results Consistent with our hypothesis, we found that basal RSNA was decreased in ArcPomc−/− mice relative to their wild type (WT) littermates. Remarkably, both WT and db/db mice exhibited elevated glycosuria and improved glucose tolerance after renal denervation. The elevated glycosuria in obese ArcPomc−/−, WT and db/db mice was due to reduced renal GLUT2 levels in the proximal tubules. Overall, we show that renal-denervated WT and diabetic mice recapitulate the phenotype of improved glucose tolerance and elevated glycosuria associated with reduced renal GLUT2 levels observed in obese ArcPomc−/− mice. Conclusion Hence, we conclude that ArcPomc is essential in maintaining basal RSNA and that elevated glycosuria is a possible mechanism to explain improved glucose tolerance after renal denervation in drug resistant hypertensive patients. Hypothalamic POMC is essential in maintaining basal renal sympathetic nerve activity. Renal denervation improves glucose tolerance in wild-type and db/db mice by elevating their glycosuria. Decreased renal GLUT2 is responsible for elevated glycosuria in mice with suppressed renal sympathetic nerve activity.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Donald A Morgan
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Benjamin P Tooke
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Case Western Reserve University, Cleveland, OH, USA
| | - Jessica M Adams
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA.
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Abstract
Leptin signaling blockade by chronic overstimulation of the leptin receptor or hypothalamic pro-inflammatory responses due to elevated levels of saturated fatty acid can induce leptin resistance by activating negative feedback pathways. Although, long form leptin receptor (Ob-Rb) initiates leptin signaling through more than seven different signal transduction pathways, excessive suppressor of cytokine signaling-3 (SOCS-3) activity is a potential mechanism for the leptin resistance that characterizes human obesity. Because the leptin-responsive metabolic pathways broadly integrate with other neurons to control energy balance, the methods used to counteract the leptin resistance has extremely limited effect. In this chapter, besides the impairment of central and peripheral leptin signaling pathways, limited access of leptin to central nervous system (CNS) through blood-brain barrier, mismatch between high leptin and the amount of leptin receptor expression, contradictory effects of cellular and circulating molecules on leptin signaling, the connection between leptin signaling and endoplasmic reticulum (ER) stress and self-regulation of leptin signaling has been discussed in terms of leptin resistance.
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Affiliation(s)
- Atilla Engin
- Faculty of Medicine, Department of General Surgery, Gazi University, Besevler, Ankara, Turkey.
- , Mustafa Kemal Mah. 2137. Sok. 8/14, 06520, Cankaya, Ankara, Turkey.
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28
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Thompson JR, Valleau JC, Barling AN, Franco JG, DeCapo M, Bagley JL, Sullivan EL. Exposure to a High-Fat Diet during Early Development Programs Behavior and Impairs the Central Serotonergic System in Juvenile Non-Human Primates. Front Endocrinol (Lausanne) 2017; 8:164. [PMID: 28785241 PMCID: PMC5519527 DOI: 10.3389/fendo.2017.00164] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 06/27/2017] [Indexed: 12/29/2022] Open
Abstract
Perinatal exposure to maternal obesity and high-fat diet (HFD) consumption not only poses metabolic risks to offspring but also impacts brain development and mental health. Using a non-human primate model, we observed a persistent increase in anxiety in juvenile offspring exposed to a maternal HFD. Postweaning HFD consumption also increased anxiety and independently increased stereotypic behaviors. These behavioral changes were associated with modified cortisol stress response and impairments in the development of the central serotonin synthesis, with altered tryptophan hydroxylase-2 mRNA expression in the dorsal and median raphe. Postweaning HFD consumption decreased serotonergic immunoreactivity in area 10 of the prefrontal cortex. These results suggest that perinatal exposure to HFD consumption programs development of the brain and endocrine system, leading to behavioral impairments associated with mental health and neurodevelopmental disorders. Also, an early nutritional intervention (consumption of the control diet at weaning) was not sufficient to ameliorate many of the behavioral changes, such as increased anxiety, that were induced by maternal HFD consumption. Given the level of dietary fat consumption and maternal obesity in developed nations these findings have important implications for the mental health of future generations.
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Affiliation(s)
- Jacqueline R. Thompson
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, United States
| | - Jeanette C. Valleau
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, United States
| | - Ashley N. Barling
- Department of Biology, University of Portland, Portland, OR, United States
| | - Juliana G. Franco
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, United States
| | - Madison DeCapo
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, United States
| | - Jennifer L. Bagley
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, United States
| | - Elinor L. Sullivan
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, United States
- Department of Biology, University of Portland, Portland, OR, United States
- *Correspondence: Elinor L. Sullivan,
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29
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Affiliation(s)
- Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, 6116 Brehm Tower, 1000 Wall Street, Ann Arbor, Michigan 48105, USA
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