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Saucisse N, Mazier W, Simon V, Binder E, Catania C, Bellocchio L, Romanov RA, Léon S, Matias I, Zizzari P, Quarta C, Cannich A, Meece K, Gonzales D, Clark S, Becker JM, Yeo GSH, Fioramonti X, Merkle FT, Wardlaw SL, Harkany T, Massa F, Marsicano G, Cota D. Functional heterogeneity of POMC neurons relies on mTORC1 signaling. Cell Rep 2021; 37:109800. [PMID: 34644574 DOI: 10.1016/j.celrep.2021.109800] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 11/13/2020] [Revised: 07/21/2021] [Accepted: 09/15/2021] [Indexed: 12/14/2022] Open
Abstract
Hypothalamic pro-opiomelanocortin (POMC) neurons are known to trigger satiety. However, these neuronal cells encompass heterogeneous subpopulations that release γ-aminobutyric acid (GABA), glutamate, or both neurotransmitters, whose functions are poorly defined. Using conditional mutagenesis and chemogenetics, we show that blockade of the energy sensor mechanistic target of rapamycin complex 1 (mTORC1) in POMC neurons causes hyperphagia by mimicking a cellular negative energy state. This is associated with decreased POMC-derived anorexigenic α-melanocyte-stimulating hormone and recruitment of POMC/GABAergic neurotransmission, which is restrained by cannabinoid type 1 receptor signaling. Electrophysiology and optogenetic studies further reveal that pharmacological blockade of mTORC1 simultaneously activates POMC/GABAergic neurons and inhibits POMC/glutamatergic ones, implying that the functional specificity of these subpopulations relies on mTORC1 activity. Finally, POMC neurons with different neurotransmitter profiles possess specific molecular signatures and spatial distribution. Altogether, these findings suggest that mTORC1 orchestrates the activity of distinct POMC neurons subpopulations to regulate feeding behavior.
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Affiliation(s)
- Nicolas Saucisse
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Wilfrid Mazier
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Vincent Simon
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Elke Binder
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Caterina Catania
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Luigi Bellocchio
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Roman A Romanov
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria
| | - Stéphane Léon
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Isabelle Matias
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Philippe Zizzari
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Carmelo Quarta
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Astrid Cannich
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Delphine Gonzales
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Samantha Clark
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Julia M Becker
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Giles S H Yeo
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Xavier Fioramonti
- NutriNeuro, UMR 1286 INRAE, Bordeaux University, Bordeaux INP, F-33000 Bordeaux, France
| | - Florian T Merkle
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK; Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge Biomedical Campus, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Sharon L Wardlaw
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Tibor Harkany
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria; Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Federico Massa
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Giovanni Marsicano
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Daniela Cota
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France.
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Panigrahi SK, Meece K, Wardlaw SL. Effects of Naltrexone on Energy Balance and Hypothalamic Melanocortin Peptides in Male Mice Fed a High-Fat Diet. J Endocr Soc 2019; 3:590-601. [PMID: 30820484 PMCID: PMC6388658 DOI: 10.1210/js.2018-00379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 11/20/2018] [Accepted: 01/23/2019] [Indexed: 01/16/2023] Open
Abstract
The hypothalamic melanocortin system composed of proopiomelanocortin (POMC) and agouti-related protein (AgRP) neurons plays a key role in maintaining energy homeostasis. The POMC-derived peptides, α-MSH and β-EP, have distinct roles in this process. α-MSH inhibits food intake, whereas β-EP, an endogenous opioid, can inhibit POMC neurons and stimulate food intake. A mouse model was used to examine the effects of opioid antagonism with naltrexone (NTX) on Pomc and Agrp gene expression and POMC peptide processing in the hypothalamus in conjunction with changes in energy balance. There were clear stimulatory effects of NTX on hypothalamic Pomc in mice receiving low- and high-fat diets, yet only transient decreases in food intake and body weight gain were noted. The effects on Pomc expression were accompanied by an increase in POMC prohormone levels and a decrease in levels of the processed peptides α-MSH and β-EP. Arcuate expression of the POMC processing enzymes Pcsk1, Pcsk2, and Cpe was not altered by NTX, but expression of Prcp, an enzyme that inactivates α-MSH, increased after NTX exposure. NTX exposure also stimulated hypothalamic Agrp expression, but the effects of NTX on energy balance were not enhanced in Agrp-null mice. Despite clear stimulatory effects of NTX on Pomc expression in the hypothalamus, only modest transient decreases in food intake and body weight were seen. Effects of NTX on POMC processing, and possibly α-MSH inactivation, as well as stimulatory effects on AgRP neurons could mitigate the effects of NTX on energy balance.
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Affiliation(s)
- Sunil K Panigrahi
- Department of Medicine, Division of Endocrinology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York
| | - Kana Meece
- Department of Medicine, Division of Endocrinology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York
| | - Sharon L Wardlaw
- Department of Medicine, Division of Endocrinology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York
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Gordon RJ, Panigrahi SK, Meece K, Atalayer D, Smiley R, Wardlaw SL. Effects of Opioid Antagonism on Cerebrospinal Fluid Melanocortin Peptides and Cortisol Levels in Humans. J Endocr Soc 2017; 1:1235-1246. [PMID: 29264449 PMCID: PMC5686644 DOI: 10.1210/js.2017-00289] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [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: 06/16/2017] [Accepted: 08/25/2017] [Indexed: 11/19/2022] Open
Abstract
CONTEXT Hypothalamic proopiomelanocortin (POMC) is processed to α-melanocyte-stimulating hormone, which interacts with the melanocortin antagonist agouti-related protein (AgRP), to regulate energy balance. The POMC-derived opioid peptide β-endorphin (β-EP) also affects feeding behavior via interactions with brain µ-opioid receptors (MORs), including autoinhibitory interactions with MOR expressed by POMC neurons. The opioid antagonist naltrexone (NTX) stimulates POMC neurons in rodents and decreases food intake. OBJECTIVE AND DESIGN The effect of NTX on brain POMC in humans was assessed by measuring POMC peptide concentrations in lumbar cerebrospinal fluid (CSF). AgRP and cortisol levels were also measured because both are inhibited by opioids. In a double-blinded crossover study, 14 healthy subjects were given NTX (50 mg daily) or placebo for either 2 or 7 days. RESULTS CSF β-EP levels increased after 2 and 7 days of NTX treatment; CSF POMC levels did not change, but the β-EP-to-POMC ratio increased. CSF AgRP levels did not change, but plasma AgRP levels tended to increase after NTX (P = 0.06). Cortisol increased in plasma and CSF after NTX treatment; these changes correlated positively with changes in AgRP levels. CONCLUSION Opioid antagonism stimulates POMC peptide release into CSF in humans. The increase in the CSF β-EP-to-POMC ratio could indicate selective release of processed peptides or an effect on POMC processing. Furthermore, AgRP and cortisol stimulation by NTX may mitigate POMC-induced decrease in food intake. It remains to be determined if biomarkers in CSF and plasma could be used to predict responses to pharmacotherapy targeting the melanocortin system.
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Affiliation(s)
- Rebecca J. Gordon
- Department of Pediatrics, Columbia University College of Physicians & Surgeons, New York, NY 10032
| | - Sunil K. Panigrahi
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, NY 10032
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, NY 10032
| | - Deniz Atalayer
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, NY 10032
| | - Richard Smiley
- Department of Anesthesiology, Columbia University College of Physicians & Surgeons, New York, NY 10032
| | - Sharon L. Wardlaw
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, NY 10032
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Wang L, Sui L, Panigrahi SK, Meece K, Xin Y, Kim J, Gromada J, Doege CA, Wardlaw SL, Egli D, Leibel RL. PC1/3 Deficiency Impacts Pro-opiomelanocortin Processing in Human Embryonic Stem Cell-Derived Hypothalamic Neurons. Stem Cell Reports 2017; 8:264-277. [PMID: 28132887 PMCID: PMC5312251 DOI: 10.1016/j.stemcr.2016.12.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 12/19/2022] Open
Abstract
We recently developed a technique for generating hypothalamic neurons from human pluripotent stem cells. Here, as proof of principle, we examine the use of these cells in modeling of a monogenic form of severe obesity: PCSK1 deficiency. The cognate enzyme, PC1/3, processes many prohormones in neuroendocrine and other tissues. We generated PCSK1 (PC1/3)-deficient human embryonic stem cell (hESC) lines using both short hairpin RNA and CRISPR-Cas9, and investigated pro-opiomelanocortin (POMC) processing using hESC-differentiated hypothalamic neurons. The increased levels of unprocessed POMC and the decreased ratios (relative to POMC) of processed POMC-derived peptides in both PCSK1 knockdown and knockout hESC-derived neurons phenocopied POMC processing reported in PC1/3-null mice and PC1/3-deficient patients. PC1/3 deficiency was associated with increased expression of melanocortin receptors and PRCP (prolylcarboxypeptidase, a catabolic enzyme for α-melanocyte stimulating hormone (αMSH)), and reduced adrenocorticotropic hormone secretion. We conclude that the obesity accompanying PCSK1 deficiency may not be primarily due to αMSH deficiency. Stem cell-derived hypothalamic neurons are used to study human obesity shRNA and CRISPR-Cas9 were used to generate models of PCSK1 deficiency PC1/3 deficiency impaired POMC processing in arcuate-like neurons Adaptive changes occurred in “downstream” POMC processing enzymes
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Affiliation(s)
- Liheng Wang
- Division of Molecular Genetics, Department of Pediatrics and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, 1150 St. Nicholas Avenue, Room 620A, New York, NY 10032, USA; Department of Medicine and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Lina Sui
- Division of Molecular Genetics, Department of Pediatrics and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, 1150 St. Nicholas Avenue, Room 620A, New York, NY 10032, USA
| | - Sunil K Panigrahi
- Department of Medicine and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Kana Meece
- Department of Medicine and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Yurong Xin
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Jinrang Kim
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | - Claudia A Doege
- Department of Pathology and Cell Biology and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Sharon L Wardlaw
- Department of Medicine and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Dieter Egli
- Division of Molecular Genetics, Department of Pediatrics and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, 1150 St. Nicholas Avenue, Room 620A, New York, NY 10032, USA; New York Stem Cell Foundation Research Institute, 3960 Broadway, New York, NY 10032, USA
| | - Rudolph L Leibel
- Division of Molecular Genetics, Department of Pediatrics and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, 1150 St. Nicholas Avenue, Room 620A, New York, NY 10032, USA; Department of Medicine and Naomi Berrie Diabetes Center, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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Page-Wilson G, Nguyen KT, Atalayer D, Meece K, Bainbridge HA, Korner J, Gordon RJ, Panigrahi SK, White A, Smiley R, Wardlaw SL. Evaluation of CSF and plasma biomarkers of brain melanocortin activity in response to caloric restriction in humans. Am J Physiol Endocrinol Metab 2017; 312:E19-E26. [PMID: 27894065 PMCID: PMC5283881 DOI: 10.1152/ajpendo.00330.2016] [Citation(s) in RCA: 12] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/11/2016] [Indexed: 11/22/2022]
Abstract
The melanocortin neuronal system, which consists of hypothalamic proopiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, is a leptin target that regulates energy balance and metabolism, but studies in humans are limited by a lack of reliable biomarkers to assess brain melanocortin activity. The objective of this study was to measure the POMC prohormone and its processed peptide, β-endorphin (β-EP), in cerebrospinal fluid (CSF) and AgRP in CSF and plasma after calorie restriction to validate their utility as biomarkers of brain melanocortin activity. CSF and plasma were obtained from 10 lean and obese subjects after fasting (40 h) and refeeding (24 h), and from 8 obese subjects before and after 6 wk of dieting (800 kcal/day) to assess changes in neuropeptide and hormone levels. After fasting, plasma leptin decreased to 35%, and AgRP increased to 153% of baseline. During refeeding, AgRP declined as leptin increased; CSF β-EP increased, but POMC did not change. Relative changes in plasma and CSF leptin were blunted in obese subjects. After dieting, plasma and CSF leptin decreased to 46% and 70% of baseline, CSF POMC and β-EP decreased, and plasma AgRP increased. At baseline, AgRP correlated negatively with insulin and homeostasis model assessment (HOMA-IR), and positively with the Matsuda index. Thus, following chronic calorie restriction, POMC and β-EP declined in CSF, whereas acutely, only β-EP changed. Plasma AgRP, however, increased after both acute and chronic calorie restriction. These results support the use of CSF POMC and plasma AgRP as biomarkers of hypothalamic melanocortin activity and provide evidence linking AgRP to insulin sensitivity.
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Affiliation(s)
- Gabrielle Page-Wilson
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York
| | - Kim T Nguyen
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York
| | - Deniz Atalayer
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York
| | - Heather A Bainbridge
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York
| | - Judith Korner
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York
| | - Rebecca J Gordon
- Department of Pediatrics, Columbia University College of Physicians & Surgeons, New York, New York
| | - Sunil K Panigrahi
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York
| | - Anne White
- Faculties of Life Sciences and Medical and Human Sciences, University of Manchester, Manchester, United Kingdom; and
| | - Richard Smiley
- Department of Anesthesiology, Columbia University College of Physicians & Surgeons, New York, New York
| | - Sharon L Wardlaw
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York;
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Page-Wilson G, Meece K, White A, Rosenbaum M, Leibel RL, Smiley R, Wardlaw SL. Proopiomelanocortin, agouti-related protein, and leptin in human cerebrospinal fluid: correlations with body weight and adiposity. Am J Physiol Endocrinol Metab 2015; 309:E458-65. [PMID: 26152765 PMCID: PMC4556883 DOI: 10.1152/ajpendo.00206.2015] [Citation(s) in RCA: 21] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/01/2015] [Indexed: 11/22/2022]
Abstract
Leptin and its neuronal targets, which produce proopiomelanocortin (POMC) and agouti-related protein (AgRP), regulate energy balance. This study characterized leptin, POMC, and AgRP in the cerebrospinal fluid (CSF) of 47 healthy human subjects, 23 lean and 24 overweight/obese (OW/OB), as related to BMI, adiposity, plasma leptin, soluble leptin receptor (s-OB-R), and insulin. POMC was measured since the POMC prohormone is the predominant POMC peptide in CSF and correlates with hypothalamic POMC in rodents. Plasma AgRP was similarly characterized. CSF leptin was 83-fold lower than in plasma and correlated strongly with BMI, body fat, and insulin. The relative amount of leptin transported into CSF declined with increasing BMI, ranging from 4.5 to 0.52%, consistent with a saturable transport mechanism. CSF sOB-R was 78-fold lower than in plasma and correlated negatively with plasma and CSF leptin. CSF POMC was higher in lean vs. OW/OB subjects (P < 0.001) and correlated negatively with CSF leptin (r = -0.60, P < 0.001) and with plasma leptin, insulin, BMI, and adiposity. CSF AgRP was not different in lean vs. OW/OB; however, plasma AgRP was higher in lean subjects (P = 0.001) and correlated negatively with BMI, adiposity, leptin, insulin, and HOMA (P < 0.005). Thus, CSF measurements may provide useful biomarkers for brain leptin and POMC activity. The striking negative correlation between CSF leptin and POMC could be secondary to leptin resistance and/or neuronal changes associated with obesity but may also indicate that POMC plays a primary role in regulating body weight and adiposity. The role of plasma AgRP as a neuroendocrine biomarker deserves further study.
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Affiliation(s)
- Gabrielle Page-Wilson
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York
| | - Anne White
- Faculties of Life Sciences and Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Michael Rosenbaum
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York; and
| | - Rudolph L Leibel
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York; and
| | - Richard Smiley
- Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Sharon L Wardlaw
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York;
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Lam DD, de Souza FSJ, Nasif S, Yamashita M, López-Leal R, Otero-Corchon V, Meece K, Sampath H, Mercer AJ, Wardlaw SL, Rubinstein M, Low MJ. Partially redundant enhancers cooperatively maintain Mammalian pomc expression above a critical functional threshold. PLoS Genet 2015; 11:e1004935. [PMID: 25671638 PMCID: PMC4335486 DOI: 10.1371/journal.pgen.1004935] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [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: 10/24/2014] [Accepted: 12/02/2014] [Indexed: 11/29/2022] Open
Abstract
Cell-specific expression of many genes is conveyed by multiple enhancers, with each individual enhancer controlling a particular expression domain. In contrast, multiple enhancers drive similar expression patterns of some genes involved in embryonic development, suggesting regulatory redundancy. Work in Drosophila has indicated that functionally overlapping enhancers canalize development by buffering gene expression against environmental and genetic disturbances. However, little is known about regulatory redundancy in vertebrates and in genes mainly expressed during adulthood. Here we study nPE1 and nPE2, two phylogenetically conserved mammalian enhancers that drive expression of the proopiomelanocortin gene (Pomc) to the same set of hypothalamic neurons. The simultaneous deletion of both enhancers abolished Pomc expression at all ages and induced a profound metabolic dysfunction including early-onset extreme obesity. Targeted inactivation of either nPE1 or nPE2 led to very low levels of Pomc expression during early embryonic development indicating that both enhancers function synergistically. In adult mice, however, Pomc expression is controlled additively by both enhancers, with nPE1 being responsible for ∼80% and nPE2 for ∼20% of Pomc transcription. Consequently, nPE1 knockout mice exhibit mild obesity whereas nPE2-deficient mice maintain a normal body weight. These results suggest that nPE2-driven Pomc expression is compensated by nPE1 at later stages of development, essentially rescuing the earlier phenotype of nPE2 deficiency. Together, these results reveal that cooperative interactions between the enhancers confer robustness of Pomc expression against gene regulatory disturbances and preclude deleterious metabolic phenotypes caused by Pomc deficiency in adulthood. Thus, our study demonstrates that enhancer redundancy can be used by genes that control adult physiology in mammals and underlines the potential significance of regulatory sequence mutations in common diseases. The stability of animal form and function in the face of genetic and environmental variation relies on consistent gene expression. Multiple enhancers, each specifying a unique regulatory domain, control the precise spatiotemporal expression of many genes. However, in some genes apparently redundant enhancers regulate expression in overlapping cell-specific patterns. Although this arrangement has been shown to be important for developmental robustness in invertebrates, the role of apparently redundant enhancers in vertebrate species and in genes functioning in adulthood is poorly understood. Here, we show that expression of the mammalian Pomc gene is controlled in a tissue-specific manner by two such apparently redundant enhancers. We used targeted deletion of the individual enhancers to delineate their respective contributions to Pomc expression in the brain. Since Pomc expression from its intact locus exceeds the sum of the individual enhancer contributions to Pomc mRNA levels in embryonic mice, we infer a synergistic action between the enhancers during development. In contrast, the interaction between the enhancers is additive in adult mice. Deletion of both enhancers simultaneously almost completely abolished Pomc expression and the mutant mice displayed extreme obesity and metabolic dysfunction, while deletion of the individual enhancers had a modest or no phenotypic effect. Together, our results demonstrate that the two enhancers cooperatively maintain Pomc expression above a critical functional threshold.
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Affiliation(s)
- Daniel D. Lam
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Flavio S. J. de Souza
- 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, Buenos Aires, Argentina
| | - Sofia Nasif
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Miho Yamashita
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | | | - Veronica Otero-Corchon
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, United States of America
| | - Harini Sampath
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Aaron J. Mercer
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sharon L. Wardlaw
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, United States of America
| | - Marcelo Rubinstein
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- 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, Buenos Aires, Argentina
| | - Malcolm J. Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
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8
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Wang L, Meece K, Williams DJ, Lo KA, Zimmer M, Heinrich G, Martin Carli J, Leduc CA, Sun L, Zeltser LM, Freeby M, Goland R, Tsang SH, Wardlaw SL, Egli D, Leibel RL. Differentiation of hypothalamic-like neurons from human pluripotent stem cells. J Clin Invest 2015; 125:796-808. [PMID: 25555215 DOI: 10.1172/jci79220] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/20/2014] [Indexed: 12/29/2022] Open
Abstract
The hypothalamus is the central regulator of systemic energy homeostasis, and its dysfunction can result in extreme body weight alterations. Insights into the complex cellular physiology of this region are critical to the understanding of obesity pathogenesis; however, human hypothalamic cells are largely inaccessible for direct study. Here, we developed a protocol for efficient generation of hypothalamic neurons from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) obtained from patients with monogenetic forms of obesity. Combined early activation of sonic hedgehog signaling followed by timed NOTCH inhibition in human ESCs/iPSCs resulted in efficient conversion into hypothalamic NKX2.1+ precursors. Application of a NOTCH inhibitor and brain-derived neurotrophic factor (BDNF) further directed the cells into arcuate nucleus hypothalamic-like neurons that express hypothalamic neuron markers proopiomelanocortin (POMC), neuropeptide Y (NPY), agouti-related peptide (AGRP), somatostatin, and dopamine. These hypothalamic-like neurons accounted for over 90% of differentiated cells and exhibited transcriptional profiles defined by a hypothalamic-specific gene expression signature that lacked pituitary markers. Importantly, these cells displayed hypothalamic neuron characteristics, including production and secretion of neuropeptides and increased p-AKT and p-STAT3 in response to insulin and leptin. Our results suggest that these hypothalamic-like neurons have potential for further investigation of the neurophysiology of body weight regulation and evaluation of therapeutic targets for obesity.
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Page-Wilson G, Freda PU, Jacobs TP, Khandji AG, Bruce JN, Foo ST, Meece K, White A, Wardlaw SL. Clinical utility of plasma POMC and AgRP measurements in the differential diagnosis of ACTH-dependent Cushing's syndrome. J Clin Endocrinol Metab 2014; 99:E1838-45. [PMID: 25013995 PMCID: PMC4184073 DOI: 10.1210/jc.2014-1448] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [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: 01/01/2023]
Abstract
CONTEXT Distinguishing between pituitary [Cushing's disease (CD)] and ectopic causes [ectopic ACTH syndrome (EAS)] of ACTH-dependent Cushing's syndrome can be challenging. Inferior petrosal sinus sampling (IPSS) best discriminates between CD and occult EAS but is a specialized procedure that is not widely available. Identifying adjunctive diagnostic tests may prove useful. In EAS, abnormal processing of the ACTH precursor proopiomelanocortin (POMC) and the accumulation of POMC-derived peptides might be expected and abnormal levels of other neuropeptides may be detected. OBJECTIVE The objective of the study was to evaluate the diagnostic utility of POMC measurements for distinguishing between CD and occult EAS in patients referred for IPSS. Another objective of the study was to evaluate in parallel the diagnostic utility of another neuropeptide, agouti-related protein (AgRP), because we have observed a 10-fold elevation of AgRP in plasma in a patient with EAS from small-cell lung cancer. DESIGN AND PARTICIPANTS Plasma POMC and AgRP were measured in 38 Cushing's syndrome patients presenting for IPSS, with either no pituitary lesion or a microadenoma on magnetic resonance imaging, and in 38 healthy controls. RESULTS Twenty-seven of 38 patients had CD; 11 of 38 had EAS. The mean POMC was higher in EAS vs CD [54.5 ± 13.0 (SEM) vs 17.2 ± 1.5 fmol/mL; P < .05]. Mean AgRP was higher in EAS vs CD (280 ± 76 vs 120 ± 16 pg/mL; P = .01). Although there was an overlap in POMC and AgRP levels between the groups, the POMC levels greater than 36 fmol/mL (n = 7) and AgRP levels greater than 280 pg/mL (n = 3) were specific for EAS. When used together, POMC greater than 36 fmol/mL and/or AgRP greater than 280 pg/mL detected 9 of 11 cases of EAS, indicating that elevations in these peptides have a high positive predictive value for occult EAS. CONCLUSIONS Expanding upon previous observations of high POMC in EAS, this study specifically demonstrates elevated POMC levels can identify occult ectopic tumors. Elevations in AgRP also favor the diagnosis of EAS, suggesting AgRP should be further evaluated as a potential neuroendocrine tumor marker.
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Affiliation(s)
- Gabrielle Page-Wilson
- Department of Medicine (G.P.-W., P.U.F., T.P.J., K.M., S.L.W.), Department of Radiology (A.G.K.), Department of Neurological Surgery (J.N.B.), Columbia University College of Physicians & Surgeons, New York, New York 10032; Department of Medicine (S.T.F.), Mt Sinai/St Luke's Roosevelt Hospital, New York, New York 10019; and Faculties of Life Sciences and Medical and Human Sciences (A.W.), University of Manchester, Manchester M13 9PT, United Kingdom
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Wardlaw SL, Burant CF, Klein S, Meece K, White A, Kasten T, Lucey BP, Bateman RJ. Continuous 24-hour leptin, proopiomelanocortin, and amino acid measurements in human cerebrospinal fluid: correlations with plasma leptin, soluble leptin receptor, and amino acid levels. J Clin Endocrinol Metab 2014; 99:2540-8. [PMID: 24670082 PMCID: PMC4079306 DOI: 10.1210/jc.2013-4087] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [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: 01/29/2023]
Abstract
CONTEXT In order to characterize diurnal changes in central leptin and its target neuropeptide, proopiomelanocortin (POMC), we measured leptin and POMC in cerebrospinal fluid (CSF) as related to changes in plasma leptin and soluble leptin receptor (sOB-R) levels. CSF and plasma levels of 20 amino acids (AA) were also measured because AA can affect brain POMC. DESIGN AND PARTICIPANTS Stored CSF and plasma samples obtained from eight healthy subjects who served as controls for a previous study were evaluated. CSF was collected hourly over 33 h via indwelling subarachnoid catheter. Leptin, sOB-R, and POMC were measured by sensitive ELISA and AA by gas chromatography-mass spectrometry. RESULTS There was a diurnal rhythm for plasma leptin with a peak at 2200 h (144% of baseline) and there was a similar diurnal rhythm for CSF leptin with a peak (117%) 3-5 h after the plasma peak. Plasma sOB-R was lowest at 0300 h and correlated negatively with plasma and CSF leptin. A diurnal rhythm for POMC in CSF was also detected with a peak (125%) at 0100 h. A positive correlation existed between CSF POMC and leptin in individual subjects over time. CSF levels of many AA increased at night. There was a significant correlation between CSF POMC and 10 AA, including leucine, isoleucine, tryptophan, and tyrosine. CONCLUSIONS Diurnal changes occur in leptin and POMC in human CSF that likely reflect changes in central leptin and melanocortin activity. Our results suggest that nocturnal elevations in leptin, AA, and POMC may help to suppress appetite and feeding at night.
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Affiliation(s)
- Sharon L Wardlaw
- Department of Medicine (S.L.W., K.M.), Columbia University College of Physicians & Surgeons, New York, New York 10032; Department of Internal Medicine (C.F.B.), University of Michigan Medical School, Ann Arbor, Michigan 48019; Center for Human Nutrition and Atkins Center for Excellence in Obesity Medicine (S.K.), Washington University School of Medicine, St Louis, Missouri 63110; Faculties of Life Sciences and Medical and Human Sciences (A.W.), University of Manchester, Manchester M13 9PL, United Kingdom; and Department of Neurology (T.K., B.P.L., R.J.B), Washington University School of Medicine, St Louis, Missouri 63110
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Heinrich G, Meece K, Wardlaw SL, Accili D. Preserved energy balance in mice lacking FoxO1 in neurons of Nkx2.1 lineage reveals functional heterogeneity of FoxO1 signaling within the hypothalamus. Diabetes 2014; 63:1572-82. [PMID: 24487022 PMCID: PMC3994959 DOI: 10.2337/db13-0651] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Transcription factor forkhead box O1 (FoxO1) regulates energy expenditure (EE), food intake, and hepatic glucose production. These activities have been mapped to specific hypothalamic neuronal populations using cell type-specific knockout experiments in mice. To parse out the integrated output of FoxO1-dependent transcription from different neuronal populations and multiple hypothalamic regions, we used transgenic mice expressing Cre recombinase from the Nkx2.1 promoter to ablate loxP-flanked Foxo1 alleles from a majority of hypothalamic neurons (Foxo1KO(Nkx2.1) mice). This strategy resulted in the expected inhibition of FoxO1 expression, but only produced a transient reduction of body weight as well as a decreased body length. The transient decrease of body weight in male mice was accompanied by decreased fat mass. Male Foxo1KO(Nkx2.1) mice show food intake similar to that in wild-type controls, and, although female knockout mice eat less, they do so in proportion to a reduced body size. EE is unaffected in Foxo1KO(Nkx2.1) mice, although small increases in body temperature are present. Unlike other neuron-specific Foxo1 knockout mice, Foxo1KO(Nkx2.1) mice are not protected from diet-induced obesity. These studies indicate that, unlike the metabolic effects of highly restricted neuronal subsets (proopiomelanocortin, neuropeptide Y/agouti-related peptide, and steroidogenic factor 1), those of neurons derived from the Nkx2.1 lineage either occur in a FoxO1-independent fashion or are compensated for through developmental plasticity.
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Affiliation(s)
- Garrett Heinrich
- Berrie Diabetes Center, Department of Medicine, College of Physicians & Surgeons, Columbia University, New York, NY
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Page-Wilson G, Reitman-Ivashkov E, Meece K, White A, Rosenbaum M, Smiley RM, Wardlaw SL. Cerebrospinal fluid levels of leptin, proopiomelanocortin, and agouti-related protein in human pregnancy: evidence for leptin resistance. J Clin Endocrinol Metab 2013; 98:264-71. [PMID: 23118421 PMCID: PMC3537103 DOI: 10.1210/jc.2012-2309] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [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: 11/19/2022]
Abstract
CONTEXT Leptin suppresses appetite by modulating the expression of hypothalamic neuropeptides including proopiomelanocortin (POMC) and agouti-related peptide (AgRP). Yet during pregnancy, caloric consumption increases despite elevated plasma leptin levels. DESIGN AND PARTICIPANTS To investigate this paradox, we measured leptin and soluble leptin receptor in plasma and leptin, POMC, and AgRP in cerebrospinal fluid (CSF) from 21 fasting pregnant women before delivery by cesarean section at a university hospital and from 14 fasting nonpregnant women. RESULTS Prepregnancy body mass index was 24.6 ± 1.1 (SE) vs. 31.3 ± 1.3 at term vs. 26.5 ± 1.6 kg/m(2) in controls. Plasma leptin (32.9 ± 4.6 vs. 16.7 ± 3.0 ng/ml) and soluble leptin receptor (30.9 ± 2.3 vs. 22.1 ± 1.4 ng/ml) levels were significantly higher in pregnant women. However, mean CSF leptin did not differ between the two groups (283 ± 34 vs. 311 ± 32 pg/ml), consistent with a relative decrease in leptin transport into CSF during pregnancy. Accordingly, the CSF/plasma leptin percentage was 1.0 ± 0.01% in pregnant subjects vs. 2.1 ± 0.2% in controls (P < 0.0001). Mean CSF AgRP was significantly higher in pregnant subjects (32.3 ± 2.7 vs. 23.5 ± 2.5 pg/ml; P = 0.03). Mean CSF POMC was not significantly different in pregnant subjects (200 ± 13.6 vs. 229 ± 17.3 fmol/ml; P = 0.190). However, the mean AgRP/POMC ratio was significantly higher among pregnant women (P = 0.003), consistent with an overall decrease in melanocortin tone favoring increased food intake during pregnancy. CONCLUSIONS These data demonstrate that despite peripheral hyperleptinemia, positive energy balance is achieved during pregnancy by a relative decrease in central leptin concentrations and resistance to leptin's effects on target neuropeptides that regulate energy balance.
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Abstract
Proopiomelanocortin (POMC) is posttranslationally processed to several peptides including α-MSH, a primary regulator of energy balance that inhibits food intake and stimulates energy expenditure. However, another POMC-derived peptide, β-endorphin (β-EP), has been shown to stimulate food intake. In this study we examined the effects of intracerebroventricular (icv) β-EP on food intake and its ability to antagonize the negative effects of α-MSH on energy balance in male rats. A single icv injection of β-EP stimulated food intake over a 2- to 6-h period during both the light and dark cycles. This effect was, however, not sustained with chronic icv β-EP infusion. In the next study, a subthreshold dose of β-EP was injected together with Nle(4), d-Phe(7) (NDP)-MSH after a 16-h fast, and the negative effects of NDP-MSH on refeeding and body weight gain were partially reversed. Finally, peptide interactions were studied in a chronic icv infusion model. Weight gain and food intake were significantly suppressed in the NDP-MSH group during the entire study. A subthreshold dose of β-EP antagonized these suppressive effects on food intake and weight gain for the first 3 d. However on d 4-7, β-EP no longer blocked these effects. Of note, the stimulatory effect of β-EP on feeding and its ability to antagonize MSH were specific for β-EP(1-31) and were not observed with β-EP(1-27). This study highlights the importance of understanding how the balance between α-MSH and β-EP is maintained and the potential role of differential POMC processing in regulating energy balance.
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Affiliation(s)
- Roxanne Dutia
- Department of Medicine, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, New York 10032, USA
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