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Ghanemi A, Yoshioka M, St-Amand J. Trefoil Factor Family Member 2: From a High-Fat-Induced Gene to a Potential Obesity Therapy Target. Metabolites 2021; 11:metabo11080536. [PMID: 34436477 PMCID: PMC8401738 DOI: 10.3390/metabo11080536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 12/11/2022] Open
Abstract
Obesity has its epidemiological patterns continuously increasing. With controlling both diet and exercise being the main approaches to manage the energy metabolism balance, a high-fat (HF) diet is of particular importance. Indeed, lipids have a low satiety potential but a high caloric density. Thus, focusing on pharmacologically targetable pathways remains an approach with promising therapeutic potential. Within this context, trefoil factor family member 2 (Tff2) has been characterized as specifically induced by HF diet rather than low-fat diet. TFF2 has also been linked to diverse neurological mechanisms and metabolic patterns suggesting its role in energy balance. The hypothesis is that TFF2 would be a HF diet-induced signal that regulates metabolism with a focus on lipids. Within this review, we put the spotlight on key findings highlighting this line of thought. Importantly, the hypothetical mechanisms pointed highlight TFF2 as an important contributor to obesity development via increasing lipids intestinal absorption and anabolism. Therefore, an outlook for future experimental activities and evaluation of the therapeutic potential of TFF2 inhibition is given. Indeed, its knockdown or downregulation would contribute to an antiobesity phenotype. We believe this work represents an addition to our understanding of the lipidic molecular implications in obesity, which will contribute to develop therapies aiming to manage the lipidic metabolic pathways including the absorption, storage and metabolism via targeting TFF2-related pathways. We briefly discuss important relevant concepts for both basic and clinical researchers.
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Affiliation(s)
- Abdelaziz Ghanemi
- Functional Genomics Laboratory, CREMI, Québec Genome Center, CHUL-CHU de Québec Research Center, Quebec, QC G1V 4G2, Canada; (A.G.); (M.Y.)
- Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec, QC G1V 0A6, Canada
| | - Mayumi Yoshioka
- Functional Genomics Laboratory, CREMI, Québec Genome Center, CHUL-CHU de Québec Research Center, Quebec, QC G1V 4G2, Canada; (A.G.); (M.Y.)
| | - Jonny St-Amand
- Functional Genomics Laboratory, CREMI, Québec Genome Center, CHUL-CHU de Québec Research Center, Quebec, QC G1V 4G2, Canada; (A.G.); (M.Y.)
- Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec, QC G1V 0A6, Canada
- Correspondence:
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McDougle M, Quinn D, Diepenbroek C, Singh A, de la Serre C, de Lartigue G. Intact vagal gut-brain signalling prevents hyperphagia and excessive weight gain in response to high-fat high-sugar diet. Acta Physiol (Oxf) 2021; 231:e13530. [PMID: 32603548 PMCID: PMC7772266 DOI: 10.1111/apha.13530] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/23/2020] [Accepted: 06/23/2020] [Indexed: 01/02/2023]
Abstract
Aim The tools that have been used to assess the function of the vagus nerve lack specificity. This could explain discrepancies about the role of vagal gut‐brain signalling in long‐term control of energy balance. Here we use a validated approach to selectively ablate sensory vagal neurones that innervate the gut to determine the role of vagal gut‐brain signalling in the control of food intake, energy expenditure and glucose homoeostasis in response to different diets. Methods Rat nodose ganglia were injected bilaterally with either the neurotoxin saporin conjugated to the gastrointestinal hormone cholecystokinin (CCK), or unconjugated saporin as a control. Food intake, body weight, glucose tolerance and energy expenditure were measured in both groups in response to chow or high‐fat high‐sugar (HFHS) diet. Willingness to work for fat or sugar was assessed by progressive ratio for orally administered solutions, while post‐ingestive feedback was tested by measuring food intake after an isocaloric lipid or sucrose pre‐load. Results Vagal deafferentation of the gut increases meal number in lean chow‐fed rats. Switching to a HFHS diet exacerbates overeating and body weight gain. The breakpoint for sugar or fat solution did not differ between groups, suggesting that increased palatability may not drive HFHS‐induced hyperphagia. Instead, decreased satiation in response to intra‐gastric infusion of fat, but not sugar, promotes hyperphagia in CCK‐Saporin‐treated rats fed with HFHS diet. Conclusions We conclude that intact sensory vagal neurones prevent hyperphagia and exacerbation of weight gain in response to a HFHS diet by promoting lipid‐mediated satiation.
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Affiliation(s)
- Molly McDougle
- Department of Pharmacodynamics University of Florida Gainesville FL USA
- Center for Integrative Cardiovascular and Metabolic Disease University of Florida Gainesville FL USA
- The John B. Pierce Laboratory New Haven CT USA
| | | | - Charlene Diepenbroek
- The John B. Pierce Laboratory New Haven CT USA
- Department of Cellular and Molecular Physiology Yale Medical School New Haven CT USA
| | - Arashdeep Singh
- Department of Pharmacodynamics University of Florida Gainesville FL USA
- Center for Integrative Cardiovascular and Metabolic Disease University of Florida Gainesville FL USA
| | | | - Guillaume de Lartigue
- Department of Pharmacodynamics University of Florida Gainesville FL USA
- Center for Integrative Cardiovascular and Metabolic Disease University of Florida Gainesville FL USA
- The John B. Pierce Laboratory New Haven CT USA
- Department of Cellular and Molecular Physiology Yale Medical School New Haven CT USA
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Wang Q, Zhang X, Leng H, Luan X, Guo F, Sun X, Gao S, Liu X, Qin H, Xu L. Zona incerta projection neurons and GABAergic and GLP-1 mechanisms in the nucleus accumbens are involved in the control of gastric function and food intake. Neuropeptides 2020; 80:102018. [PMID: 32000986 DOI: 10.1016/j.npep.2020.102018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 01/11/2020] [Accepted: 01/13/2020] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Our aim was to explore the effect of γ-aminobutyric acid (GABA) signaling in the nucleus accumbens (NAc) on promoting gastric function and food intake through glucagon-like peptide 1 (GLP-1)-sensitive gastric distension (GD) neurons under the regulatory control of the zona incerta (ZI). METHODS GABA neuronal projections were traced using retrograde tracing following fluorescence immunohistochemistry. An extracellular electrophysiological recording method was used to observe the firing of neurons in the NAc. HPLC was used to quantify the GABA and glutamate levels in the NAc after electrical stimulation of the ZI. Gastric functions including gastric motility and secretion, as well as food intake, were measured after the administration of different concentrations of GABA in the NAc or electrical stimulation of the ZI. RESULTS Some of the GABA-positive neurons arising from the ZI projected to the NAc. Some GABA-A receptor (GABA-AR)-immunoreactive neurons in the NAc were also positive for GLP-1 receptor (GLP-1R) immunoreactivity. The firing of most GLP-1-sensitive GD neurons was decreased by GABA infusion in the NAc. Intra-NAc GABA administration also promoted gastric function and food intake. The responses induced by GABA were partially blocked by the GABA-AR antagonist bicuculline (BIC) and weakened by the GLP-1R antagonist exendin 9-39 (Ex9). Electrical stimulation of the ZI changed the firing patterns of most GLP-1-sensitive GD neurons in the NAc and promoted gastric function and food intake. Furthermore, these excitatory effects induced by electrical stimulation of the ZI were weakened by preadministration of BIC in the NAc. CONCLUSION Retrograde tracing and immunohistochemical staining showed a GABAergic pathway from the ZI to the NAc. GABAergic and GLP-1 mechanisms in the NAc are involved in the control of gastric function and food intake. In addition, the interaction (direct or indirect) between the ZI and these NAc mechanisms is involved in the control of gastric function and food intake.
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Affiliation(s)
- Qian Wang
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiaoqian Zhang
- Doctoral School of Biomedical Sciences, KU Leuven, B-300 Leuven, Belgium; Family Medicine Department, Qingdao United Family Hospital, Qingdao, Shandong 266001, China
| | - Hui Leng
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiao Luan
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Feifei Guo
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiangrong Sun
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Shengli Gao
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xuehuan Liu
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Hao Qin
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Luo Xu
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China.
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Leng H, Zhang X, Wang Q, Luan X, Sun X, Guo F, Gao S, Liu X, Xu L. Regulation of stress-induced gastric ulcers via central oxytocin and a potential mechanism through the VTA-NAc dopamine pathway. Neurogastroenterol Motil 2019; 31:e13655. [PMID: 31172654 DOI: 10.1111/nmo.13655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/29/2019] [Accepted: 05/24/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Oxytocin (OT) plays an important role in regulating gastric function. How OT regulates stress-induced gastric ulcers is not understood. We investigated OT's protective role in stress-induced gastric ulcers, with a focus on OT's interaction with the ventral tegmental area (VTA) to nucleus accumbens (NAc) dopamine pathway. METHODS Drugs administration into the rats brain nuclei by brain stereotaxic apparatus, to examine related changes in gastric ulcer index, pH of gastric content, and mucus secretion, and to determine complex interactions between OT and DA systems in the regulation of stress and gastric functions. KEY RESULTS Neurons in the VTA were co-immunoreactive for the OT receptor (OTR) and DA. In a rat model of stress-induced ulcer, water-immersion restricted stress, direct administration of OT into the VTA significantly reduced gastric ulcer index and increased the pH of gastric content and mucus secretion. OT's effects were eliminated by pretreatment with the OTR antagonist atosiban in the VTA and weakened with pretreatment of the DA D2 receptor (DA D2R) antagonist raclopride in the NAc. In OTR gene knockout (Oxtr-/- ) mice, OT's protective effect was lost. OT administered to the VTA of dorsal motor nucleus of the vagus (DMV)-lesioned rats had minimal protective effects on gastric mucosa. CONCLUSIONS AND INFERENCES This study provides important data necessary for a deeper understanding of the complex interactions between OT and DA systems in the regulation of stress and gastric functions. It provides relevant mechanistic clues into OT's role as a protective factor against stress-induced changes to gastric function.
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Affiliation(s)
- Hui Leng
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
| | - Xiaoqian Zhang
- Doctoral School of Biomedical Sciences, Leuven, Belgium.,Family Medicine Department, Qingdao United Family Hospital, Qingdao, China
| | - Qian Wang
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
| | - Xiao Luan
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
| | - Xiangrong Sun
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
| | - Feifei Guo
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
| | - Shengli Gao
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
| | - Xuehuan Liu
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
| | - Luo Xu
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
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Ivetic M, Bhattacharyya A, Zemkova H. P2X2 Receptor Expression and Function Is Upregulated in the Rat Supraoptic Nucleus Stimulated Through Refeeding After Fasting. Front Cell Neurosci 2019; 13:284. [PMID: 31297050 PMCID: PMC6607214 DOI: 10.3389/fncel.2019.00284] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/12/2019] [Indexed: 01/12/2023] Open
Abstract
Magnocellular neurons in the supraoptic nucleus (SON), which synthesize and release arginine vasopressin (AVP) and oxytocin (OT), express several subtypes of ATP-stimulated purinergic P2X receptors (P2XR) that modulate neuronal activity as well as neurotransmitter and hormone release. However, the physiological impact of this modulation is not well understood. Here, we tested a hypothesis that P2XRs play a role in the sustained release of hormones from SON neurons stimulated through fasting/refeeding. We studied the effect of 2 h of refeeding after 48 h of fasting on P2XR and P2YR mRNA expression and ATP-induced presynaptic and postsynaptic responses in the SON of 30-day-old rats. Quantitative real-time PCR revealed that the expression of P2X2R and AVP mRNA was upregulated, whereas P2X4R, P2X7R, P2Y2R, and OT mRNA levels were not significantly changed and P2Y1R mRNA expression was decreased. Whole-cell patch clamp recordings performed on isolated rat brain slices showed that the amplitude of the ATP-stimulated somatic current and the ATP-induced increases in the frequency of spontaneous GABAergic inhibitory postsynaptic currents were significantly higher in SON neurons from fasted/refed rats than in SON neurons from normally fed rats. No evidence was found for changes in the presynaptic effect of ATP in SON neurons not expressing somatic P2XRs. These results suggest that the increased activity of SON neurons synthesizing AVP is associated with enhanced expression of P2X2Rs on neuronal cell bodies and their GABAergic presynaptic nerve terminals.
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Affiliation(s)
- Milorad Ivetic
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Anirban Bhattacharyya
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Hana Zemkova
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czechia
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Li C, Navarrete J, Liang-Guallpa J, Lu C, Funderburk SC, Chang RB, Liberles SD, Olson DP, Krashes MJ. Defined Paraventricular Hypothalamic Populations Exhibit Differential Responses to Food Contingent on Caloric State. Cell Metab 2019; 29:681-694.e5. [PMID: 30472090 PMCID: PMC6402975 DOI: 10.1016/j.cmet.2018.10.016] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/12/2018] [Accepted: 10/24/2018] [Indexed: 01/15/2023]
Abstract
Understanding the neural framework behind appetite control is fundamental to developing effective therapies to combat the obesity epidemic. The paraventricular hypothalamus (PVH) is critical for appetite regulation, yet, the real-time, physiological response properties of PVH neurons to nutrients are unknown. Using a combination of fiber photometry, electrophysiology, immunohistochemistry, and neural manipulation strategies, we determined the population dynamics of four molecularly delineated PVH subsets implicated in feeding behavior: glucagon-like peptide 1 receptor (PVHGlp1r), melanocortin-4 receptor (PVHMc4r), oxytocin (PVHOxt), and corticotropin-releasing hormone (PVHCrh). We identified both calorie- and state-dependent sustained activity increases and decreases in PVHGlp1r and PVHCrh populations, respectively, while observing transient bulk changes of PVHMc4r, but no response in PVHOxt, neurons to food. Furthermore, we highlight the role of PVHGlp1r neurons in orchestrating acute feeding behavior, independent of the anti-obesity drug liraglutide, and demonstrate the indispensability of PVHGlp1r and PVHMc4r, but not PVHOxt or PVHCrh neurons, in body weight maintenance.
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Affiliation(s)
- Chia Li
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA; National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD 21224, USA
| | - Jovana Navarrete
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA; National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD 21224, USA
| | - Jing Liang-Guallpa
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA; Brown University Graduate Partnerships Program, Providence, RI 02912, USA; National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD 21224, USA
| | - Chunxia Lu
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Samuel C Funderburk
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA; National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD 21224, USA
| | - Rui B Chang
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen D Liberles
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michael J Krashes
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA; National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD 21224, USA.
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7
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de Ávila C, Chometton S, Lenglos C, Calvez J, Gundlach AL, Timofeeva E. Differential effects of relaxin-3 and a selective relaxin-3 receptor agonist on food and water intake and hypothalamic neuronal activity in rats. Behav Brain Res 2018; 336:135-144. [DOI: 10.1016/j.bbr.2017.08.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/21/2017] [Accepted: 08/28/2017] [Indexed: 12/22/2022]
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8
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Maruyama M, Hotta N, Nio Y, Hamagami K, Nagi T, Funata M, Sakamoto J, Nakakariya M, Amano N, Nishida M, Okawa T, Arikawa Y, Sasaki S, Kasai S, Nagisa Y, Habata Y, Mori M. Bombesin receptor subtype-3-expressing neurons regulate energy homeostasis through a novel neuronal pathway in the hypothalamus. Brain Behav 2018; 8:e00881. [PMID: 29568682 PMCID: PMC5853643 DOI: 10.1002/brb3.881] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 10/16/2017] [Accepted: 10/19/2017] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVES Bombesin receptor subtype-3 (BRS-3) has been suggested to play a potential role in energy homeostasis. However, the physiological mechanism of BRS-3 on energy homeostasis remains unknown. Thus, we investigated the BRS-3-mediated neuronal pathway involved in food intake and energy expenditure. MATERIALS AND METHODS Expression of BRS-3 in the rat brain was histologically examined. The BRS-3 neurons activated by refeeding-induced satiety or a BRS-3 agonist were identified by c-Fos immunostaining. We also analyzed expression changes in feeding-relating peptides in the brain of fasted rats administered with the BRS-3 agonist. RESULTS In the paraventricular hypothalamic nucleus (PVH), dorsomedial hypothalamic nucleus (DMH), and medial preoptic area (MPA), strong c-Fos induction was observed in the BRS-3 neurons especially in PVH after refeeding. However, the BRS-3 neurons in the PVH did not express feeding-regulating peptides, while the BRS-3 agonist administration induced c-Fos expression in the DMH and MPA, which were not refeeding-sensitive, as well as in the PVH. The BRS-3 agonist administration changed the Pomc and Cart mRNA level in several brain regions of fasted rats. CONCLUSION These results suggest that BRS-3 neurons in the PVH are a novel functional subdivision in the PVH that regulates feeding behavior. As the MPA and DMH are reportedly involved in thermoregulation and energy metabolism, the BRS-3 neurons in the MPA/DMH might mediate the energy expenditure control. POMC and CART may contribute to BRS-3 neuron-mediated energy homeostasis regulation. In summary, BRS-3-expressing neurons could regulate energy homeostasis through a novel neuronal pathway.
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Affiliation(s)
- Minoru Maruyama
- Cardiovascular and Metabolic Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Natsu Hotta
- Cardiovascular and Metabolic Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Yasunori Nio
- Extra Value Generation & General Medicine Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Kenichi Hamagami
- Cardiovascular and Metabolic Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Toshimi Nagi
- Central Nervous System Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Masaaki Funata
- Biomolecular Research Laboratories Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Junichi Sakamoto
- Biomolecular Research Laboratories Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Masanori Nakakariya
- Drug Metabolism and Pharmacokinetics Research LaboratoriesTakeda Pharmaceutical Company Limited Kanagawa Japan
| | - Nobuyuki Amano
- Drug Metabolism and Pharmacokinetics Research LaboratoriesTakeda Pharmaceutical Company Limited Kanagawa Japan
| | - Mayumi Nishida
- Integrated Technology Research Laboratories Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Tomohiro Okawa
- Central Nervous System Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Yasuyoshi Arikawa
- Central Nervous System Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Shinobu Sasaki
- Medicinal Chemistry Research Laboratories Pharmaceutical Research Division Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Shizuo Kasai
- Cardiovascular and Metabolic Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
| | - Yasutaka Nagisa
- Cardiovascular and Metabolic Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan.,Present address: CVM Marketing Japan Pharma Business UnitTakeda Pharmaceutical Co. Ltd.12-10, Nihonbashi 2-Chome, Chuo-ku Tokyo 103-8686 Japan
| | - Yugo Habata
- Cardiovascular and Metabolic Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan.,Present address: Foods & Nutrients Yamanashi Gakuin Junior College Sakaori 2-4-5, Kofu Yamanashi 400-8575 Japan
| | - Masaaki Mori
- Cardiovascular and Metabolic Drug Discovery Unit Takeda Pharmaceutical Company Limited Kanagawa Japan
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Guillebaud F, Girardet C, Abysique A, Gaigé S, Barbouche R, Verneuil J, Jean A, Leprince J, Tonon MC, Dallaporta M, Lebrun B, Troadec JD. Glial Endozepines Inhibit Feeding-Related Autonomic Functions by Acting at the Brainstem Level. Front Neurosci 2017; 11:308. [PMID: 28611581 PMCID: PMC5447764 DOI: 10.3389/fnins.2017.00308] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/16/2017] [Indexed: 01/05/2023] Open
Abstract
Endozepines are endogenous ligands for the benzodiazepine receptors and also target a still unidentified GPCR. The endozepine octadecaneuropeptide (ODN), an endoproteolytic processing product of the diazepam-binding inhibitor (DBI) was recently shown to be involved in food intake control as an anorexigenic factor through ODN-GPCR signaling and mobilization of the melanocortinergic signaling pathway. Within the hypothalamus, the DBI gene is mainly expressed by non-neuronal cells such as ependymocytes, tanycytes, and protoplasmic astrocytes, at levels depending on the nutritional status. Administration of ODN C-terminal octapeptide (OP) in the arcuate nucleus strongly reduces food intake. Up to now, the relevance of extrahypothalamic targets for endozepine signaling-mediated anorexia has been largely ignored. We focused our study on the dorsal vagal complex located in the caudal brainstem. This structure is strongly involved in the homeostatic control of food intake and comprises structural similarities with the hypothalamus. In particular, a circumventricular organ, the area postrema (AP) and a tanycyte-like cells forming barrier between the AP and the adjacent nucleus tractus solitarius (NTS) are present. We show here that DBI is highly expressed by ependymocytes lining the fourth ventricle, tanycytes-like cells, as well as by proteoplasmic astrocytes located in the vicinity of AP/NTS interface. ODN staining observed at the electron microscopic level reveals that ODN-expressing tanycyte-like cells and protoplasmic astrocytes are sometimes found in close apposition to neuronal elements such as dendritic profiles or axon terminals. Intracerebroventricular injection of ODN or OP in the fourth ventricle triggers c-Fos activation in the dorsal vagal complex and strongly reduces food intake. We also show that, similarly to leptin, ODN inhibits the swallowing reflex when microinjected into the swallowing pattern generator located in the NTS. In conclusion, we hypothesized that ODN expressing cells located at the AP/NTS interface could release ODN and modify excitability of NTS neurocircuitries involved in food intake control.
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Affiliation(s)
- Florent Guillebaud
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Clémence Girardet
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Anne Abysique
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Stéphanie Gaigé
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Rym Barbouche
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Jérémy Verneuil
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - André Jean
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Jérôme Leprince
- Institut National de la Santé et de la Recherche Médicale U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine, University of Rouen NormadieMont-Saint-Aignan, France
| | - Marie-Christine Tonon
- Institut National de la Santé et de la Recherche Médicale U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine, University of Rouen NormadieMont-Saint-Aignan, France
| | - Michel Dallaporta
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Bruno Lebrun
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
| | - Jean-Denis Troadec
- Laboratoire Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif EA 4674, Faculté des Sciences et Techniques de St Jérôme, Université Aix-MarseilleMarseille, France
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10
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Sabbatini M, Grossini E, Molinari C, Mary DASG, Vacca G, Cannas M. Gastric distension causes changes in heart rate and arterial blood pressure by affecting the crosstalk between vagal and splanchnic systems in anesthetised rats. Exp Brain Res 2017; 235:1081-1095. [PMID: 28091707 DOI: 10.1007/s00221-016-4819-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 11/01/2016] [Indexed: 12/31/2022]
Abstract
Various hindbrain nuclei have been demonstrated to be involved in the control of the cardiovascular reflexes elicited by both non-noxious and noxious gastric distension, through parasympathetic and sympathetic activation. The different role played by the branches of autonomic nervous system in exerting these effects and their crosstalk in relation to low-/high-pressure distension rate has not been examined yet. Therefore, in the present work, monolateral and bilateral vagotomy and splanchnicotomy were performed in anesthetised rats to analyse the involvement of hindbrain nuclei in haemodynamic changes caused by gastric distension at high (80 mmHg) and low (15 mmHg) pressure. The analysis of c-Fos expression in neuronal areas involved in cardiovascular control allowed us to examine their recruitment in response to various patterns of gastric distension and the crosstalk between vagal and splanchnic systems. The results obtained show that the low-pressure (non-noxious) gastric distension increases both heart rate and arterial blood pressure. In addition, the vagus nerve and hindbrain nuclei, such as nucleus ambiguous, ventrolateral medulla and lateral reticular nucleus, appear to be primarily involved in observed responses. In particular, we have found that although vagus nerve plays a central role in exerting those cardiovascular reflex changes at low gastric distension, for its functional expression an intact splanchnic system is mandatory. Hence, the absence of splanchnic input attenuates pressor responses or turns them into depressor responses. Instead at high-pressure (noxious) gastric distension, the splanchnic nerve represents the primary component in regulating the reflex cardiovascular effects.
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Affiliation(s)
- Maurizio Sabbatini
- Department of Science and Technology Innovation, University of Eastern Piedmont, UPO, T. Michel, 11, Alessandria, 15121, Italia.
| | - Elena Grossini
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - Claudio Molinari
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - David A S G Mary
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - Giovanni Vacca
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - Mario Cannas
- Department of Health Sciences, University of Eastern Piedmont, UPO, Novara, Italia
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11
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Kania A, Gugula A, Grabowiecka A, de Ávila C, Blasiak T, Rajfur Z, Lewandowski MH, Hess G, Timofeeva E, Gundlach AL, Blasiak A. Inhibition of oxytocin and vasopressin neuron activity in rat hypothalamic paraventricular nucleus by relaxin-3-RXFP3 signalling. J Physiol 2017; 595:3425-3447. [PMID: 28098344 DOI: 10.1113/jp273787] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 12/23/2016] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Relaxin-3 is a stress-responsive neuropeptide that acts at its cognate receptor, RXFP3, to alter behaviours including feeding. In this study, we have demonstrated a direct, RXFP3-dependent, inhibitory action of relaxin-3 on oxytocin and vasopressin paraventricular nucleus (PVN) neuron electrical activity, a putative cellular mechanism of orexigenic actions of relaxin-3. We observed a Gαi/o -protein-dependent inhibitory influence of selective RXFP3 activation on PVN neuronal activity in vitro and demonstrated a direct action of RXFP3 activation on oxytocin and vasopressin PVN neurons, confirmed by their abundant expression of RXFP3 mRNA. Moreover, we demonstrated that RXFP3 activation induces a cadmium-sensitive outward current, which indicates the involvement of a characteristic magnocellular neuron outward potassium current. Furthermore, we identified an abundance of relaxin-3-immunoreactive axons/fibres originating from the nucleus incertus in close proximity to the PVN, but associated with sparse relaxin-3-containing fibres/terminals within the PVN. ABSTRACT The paraventricular nucleus of the hypothalamus (PVN) plays an essential role in the control of food intake and energy expenditure by integrating multiple neural and humoral inputs. Recent studies have demonstrated that intracerebroventricular and intra-PVN injections of the neuropeptide relaxin-3 or selective relaxin-3 receptor (RXFP3) agonists produce robust feeding in satiated rats, but the cellular and molecular mechanisms of action associated with these orexigenic effects have not been identified. In the present studies, using rat brain slices, we demonstrated that relaxin-3, acting through its cognate G-protein-coupled receptor, RXFP3, hyperpolarized a majority of putative magnocellular PVN neurons (88%, 22/25), including cells producing the anorexigenic neuropeptides, oxytocin and vasopressin. Importantly, the action of relaxin-3 persisted in the presence of tetrodotoxin and glutamate/GABA receptor antagonists, indicating its direct action on PVN neurons. Similar inhibitory effects on PVN oxytocin and vasopressin neurons were produced by the RXFP3 agonist, RXFP3-A2 (82%, 80/98 cells). In situ hybridization histochemistry revealed a strong colocalization of RXFP3 mRNA with oxytocin and vasopressin immunoreactivity in rat PVN neurons. A smaller percentage of putative parvocellular PVN neurons was sensitive to RXFP3-A2 (40%, 16/40 cells). These data, along with a demonstration of abundant peri-PVN and sparse intra-PVN relaxin-3-immunoreactive nerve fibres, originating from the nucleus incertus, the major source of relaxin-3 neurons, identify a strong inhibitory influence of relaxin-3-RXFP3 signalling on the electrical activity of PVN oxytocin and vasopressin neurons, consistent with the orexigenic effect of RXFP3 activation observed in vivo.
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Affiliation(s)
- Alan Kania
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Anna Gugula
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Agnieszka Grabowiecka
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Camila de Ávila
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada, G1V 0A6
| | - Tomasz Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Zenon Rajfur
- Faculty of Physics, Astronomy and Applied Computer Science, Institute of Physics, Jagiellonian University, 30-348, Krakow, Poland
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Grzegorz Hess
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland.,Institute of Pharmacology, Polish Academy of Sciences, 31-343, Krakow, Poland
| | - Elena Timofeeva
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada, G1V 0A6
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, 3052, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, VIC, 3010, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, VIC, 3010, Australia
| | - Anna Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
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12
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Barna J, Renner E, Arszovszki A, Cservenák M, Kovács Z, Palkovits M, Dobolyi A. Suckling induced activation pattern in the brain of rat pups. Nutr Neurosci 2017; 21:317-327. [PMID: 28185482 DOI: 10.1080/1028415x.2017.1286446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES The aim of the study was to understand the effects of suckling on the brain of the pups by mapping their brain activation pattern in response to suckling. METHODS The c-fos method was applied to identify activated neurons. Fasted rat pups were returned to their mothers for suckling and sacrificed 2 hours later for Fos immunohistochemistry. Double labeling was also performed to characterize some of the activated neurons. For comparison, another group of fasted pups were given dry food before Fos mapping. RESULTS After suckling, we found an increase in the number of Fos-immunoreactive neurons in the insular and somatosensory cortices, central amygdaloid nucleus (CAm), paraventricular (PVN) and supraoptic hypothalamic nuclei, lateral parabrachial nucleus (LPB), nucleus of the solitary tract (NTS), and the area postrema. Double labeling experiments demonstrated the activation of calcitonin gene-related peptide-ir (CGRP-ir) neurons in the LPB, corticotropin-releasing hormone-ir (CRH-ir) but not oxytocin-ir neurons in the PVN, and noradrenergic neurons in the NTS. In the CAm, Fos-ir neurons did not contain CRH but were apposed to CGRP-ir fiber terminals. Refeeding with dry food-induced Fos activation in all brain areas activated by suckling. The degree of activation was higher following dry food consumption than suckling in the insular cortex, and lower in the supraoptic nucleus and the NTS. Furthermore, the accumbens, arcuate, and dorsomedial hypothalamic nuclei, and the lateral hypothalamic area, which were not activated by suckling, showed activation by dry food. DISCUSSION Neurons in a number of brain areas are activated during suckling, and may participate in the signaling of satiety, taste perception, reward, food, and salt balance regulation.
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Affiliation(s)
- János Barna
- a Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology , Semmelweis University , Budapest , Hungary
| | - Eva Renner
- b MTA-SOTE NAP_A Human Brain Tissue Bank and Laboratory, Semmelweis University and the Hungarian Academy of Sciences , Budapest , Hungary
| | - Antónia Arszovszki
- c MTA-ELTE NAP_B Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology , Eötvös Loránd University and the Hungarian Academy of Sciences , Budapest , Hungary
| | - Melinda Cservenák
- a Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology , Semmelweis University , Budapest , Hungary.,c MTA-ELTE NAP_B Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology , Eötvös Loránd University and the Hungarian Academy of Sciences , Budapest , Hungary
| | - Zsolt Kovács
- d Department of Zoology , University of West Hungary, Savaria Campus , Szombathely , Hungary
| | - Miklós Palkovits
- b MTA-SOTE NAP_A Human Brain Tissue Bank and Laboratory, Semmelweis University and the Hungarian Academy of Sciences , Budapest , Hungary
| | - Arpád Dobolyi
- a Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology , Semmelweis University , Budapest , Hungary.,c MTA-ELTE NAP_B Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology , Eötvös Loránd University and the Hungarian Academy of Sciences , Budapest , Hungary
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13
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Nagarajan G, Jurkevich A, Kang SW, Kuenzel WJ. Diencephalic and septal structures containing the avian vasotocin receptor (V1aR) involved in the regulation of food intake in chickens, Gallus gallus. Physiol Behav 2016; 164:268-76. [PMID: 27317836 DOI: 10.1016/j.physbeh.2016.06.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 05/23/2016] [Accepted: 06/14/2016] [Indexed: 12/31/2022]
Abstract
Recently, it was found that the avian central vasotocin receptor (V1aR) is associated with the regulation of food intake. To identify V1aR-containing brain structures regulating food intake, a selective V1aR antagonist SR-49059 that induced food intake was administrated intracerebroventricularly in male chickens followed by detection of brain structures using FOS immunoreactivity. Particularly, the hypothalamic core region of the paraventricular nucleus, lateral hypothalamic area, dorsomedial hypothalamic nucleus, a subnucleus of the central extended amygdalar complex [dorsolateral bed nucleus of the stria terminalis], medial septal nucleus and caudal brainstem [nucleus of the solitary tract] showed significantly increased FOS-ir cells. On the other hand, the supraoptic nucleus of the preoptic area and the nucleus of the hippocampal commissure of the septum showed suppressed FOS immunoreactivity in the V1aR antagonist treatment group. Further investigation revealed that neuronal activity of arginine vasotocin (AVT-ir) magnocellular neurons in the supraoptic nucleus, preoptic periventricular nucleus, paraventricular nucleus and ventral periventricular hypothalamic nucleus and most likely corticotropin releasing hormone (CRH-ir) neurons in the nucleus of the hippocampal commissure were reduced following the antagonist treatment. Dual immunofluorescence labeling results showed that perikarya of AVT-ir magnocellular neurons in the preoptic area and hypothalamus were colabeled with V1aR. Within the nucleus of the hippocampal commissure, CRH-ir neurons were shown in close contact with V1aR-ir glial cells. Results of the present study suggest that the V1aR plays a role in the regulation of food intake by modulating neurons that synthesize and release anorectic neuropeptides in the avian brain.
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Affiliation(s)
- Gurueswar Nagarajan
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Alexander Jurkevich
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Seong W Kang
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Wayne J Kuenzel
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
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Rouquet T, Clément P, Gaigé S, Tardivel C, Roux J, Dallaporta M, Bariohay B, Troadec JD, Lebrun B. Acute oral metformin enhances satiation and activates brainstem nesfatinergic neurons. Obesity (Silver Spring) 2014; 22:2552-62. [PMID: 25236366 DOI: 10.1002/oby.20902] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/18/2014] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The study was designed to determine metformin effects on meal pattern, gastric emptying, energy expenditure, and to identify metformin-sensitive neurons and their phenotype. METHODS This study was performed on C57BL/6J and obese/diabetic (db/db) mice. Metformin (300 mg/kg) was administered by oral gavage. Food intake, meal pattern, oxygen consumption (VO2 ), and carbon dioxide production (VCO2 ) were obtained using an Oxylet Physiocage System. Gastric emptying assay and real-time RT-PCR from dorsal vagal complex extracts were also performed. C-Fos expression was used as a marker of neuronal activation. Phenotypic characterization of activated neurons was performed using either proopiomelanocortin (POMC)-Tau-Topaz GFP transgenic mice or NUCB2/nesfatin-1 and tyrosine hydroxylase (TH) labeling. RESULTS Acute per os metformin treatment slowed down gastric emptying, reduced meal size, but not meal number in a leptin-independent manner, and transiently decreased energy expenditure in a leptin-dependent manner. Metformin specifically activated central circuitry within the brainstem, independently of vagal afferents. Finally, while POMC neurons seemed sparsely activated, we report that a high proportion of the c-Fos positive cells were nesfatinergic neurons, some of which coexpressing TH. CONCLUSIONS Altogether, these results show that metformin modifies satiation by activating brainstem circuitry and suggest that NUCB2/nesfatin-1 could be involved in this metformin effect.
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Affiliation(s)
- Thaïs Rouquet
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme, Aix-Marseille Université, Marseille, France; Biomeostasis CRO, FST St Jérôme, Marseille, France
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15
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Lenglos C, Mitra A, Guèvremont G, Timofeeva E. Regulation of expression of relaxin-3 and its receptor RXFP3 in the brain of diet-induced obese rats. Neuropeptides 2014; 48:119-32. [PMID: 24629399 DOI: 10.1016/j.npep.2014.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 02/04/2014] [Accepted: 02/13/2014] [Indexed: 02/08/2023]
Abstract
An animal model closely related to human obesity is diet-induced obesity in Sprague-Dawley rats. These rats placed on a high-energy (HE) diet show wide distribution in body weight gain with a subset of animals developing diet-induced obesity (DIO) and the remaining animals showing a diet-resistant (DR) phenotype. Once obesity is established, DIO rats strongly defend their increased body weight against caloric restriction. There is evidence that neuropeptide relaxin-3 is involved in food intake regulation, but the levels of expression of relaxin-3 and its receptor have not been yet demonstrated in the DIO model. The present study investigated the brain expression of relaxin-3 and its cognate receptor RXFP3 in DIO and DR rats maintained on an HE diet since weaning. Expression of relaxin-3 and RXFP3 mRNAs was assessed by in situ hybridization in ad libitum, food-deprived (12 h) and refed (1 h) feeding states. The levels of expression of relaxin-3 in the medial portion of the nucleus incertus (NI) were higher in the DIO rats compared to the DR rats in the ad libitum-fed state. Food deprivation increased the levels of expression of relaxin-3 in the medial NI in DR but not DIO rats. The stronger expression of relaxin-3 in the ad libitum-fed state in the DIO rats was accompanied by low expression of the RXFP3 receptor in the paraventricular hypothalamic nucleus (PVN), supraoptic nucleus, central amygdala (CeA), NI, and nucleus of the solitary tract (NTS). Refeeding increased expression of RXFP3 in the paraventricular thalamic nucleus, parvocellular PVN, CeA, NI, and NTS in the DIO rats. These results provide evidence that DIO rats show a constitutive increase in relaxin-3 expression in the medial NI and that refeeding after food deprivation may enhance the orexigenic effects of relaxin-3 in DIO rats by rapid upregulation of the expression of RXFP3 in the specific brain regions involved in food intake regulation.
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Affiliation(s)
- Christophe Lenglos
- Faculté de Médecine, Département Psychiatrie et Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC G1V 4G5, Canada
| | - Arojit Mitra
- Faculté de Médecine, Département Psychiatrie et Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC G1V 4G5, Canada
| | - Geneviève Guèvremont
- Faculté de Médecine, Département Psychiatrie et Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC G1V 4G5, Canada
| | - Elena Timofeeva
- Faculté de Médecine, Département Psychiatrie et Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC G1V 4G5, Canada.
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16
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Gaigé S, Djelloul M, Tardivel C, Airault C, Félix B, Jean A, Lebrun B, Troadec JD, Dallaporta M. Modification of energy balance induced by the food contaminant T-2 toxin: a multimodal gut-to-brain connection. Brain Behav Immun 2014; 37:54-72. [PMID: 24355099 DOI: 10.1016/j.bbi.2013.12.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/27/2013] [Accepted: 12/10/2013] [Indexed: 12/12/2022] Open
Abstract
T-2 toxin is one of the most toxic Fusarium-derived trichothecenes found on cereals and constitutes a widespread contaminant of agricultural commodities as well as commercial foods. Low doses toxicity is characterized by reduced weight gain. To date, the mechanisms by which this mycotoxin profoundly modifies feeding behavior remain poorly understood and more broadly the effects of T-2 toxin on the central nervous system (CNS) have received limited attention. Through an extensive characterization of sickness-like behavior induced by T-2 toxin, we showed that its per os (p.o.) administration affects not only feeding behavior but also energy expenditure, glycaemia, body temperature and locomotor activity. Using c-Fos expression mapping, we identified the neuronal structures activated in response to T-2 toxin and observed that the pattern of neuronal populations activated by this toxin resembled that induced by inflammatory signals. Interestingly, part of neuronal pathways activated by the toxin were NUCB-2/nesfatin-1 expressing neurons. Unexpectedly, while T-2 toxin induced a strong peripheral inflammation, the brain exhibited limited inflammatory response at a time point when anorexia was ongoing. Unilateral vagotomy partly reduced T-2 toxin-induced brainstem neuronal activation. On the other hand, intracerebroventricular (icv) T-2 toxin injection resulted in a rapid (<1h) reduction in food intake. Thus, we hypothesized that T-2 toxin could signal to the brain through neuronal and/or humoral pathways. The present work provides the first demonstration that T-2 toxin modifies feeding behavior by interfering with central neuronal networks devoted to central energy balance. Our results, with a particular attention to peripheral inflammation, strongly suggest that inflammatory mediators partake in the T-2 toxin-induced anorexia and other symptoms. In view of the broad human and breeding animal exposure to T-2 toxin, this new mechanism may lead to reconsider the impact of the consumption of this toxin on human health.
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Affiliation(s)
- Stéphanie Gaigé
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France
| | - Mehdi Djelloul
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France
| | - Catherine Tardivel
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France; INRA U1189, Département AlimH, 63122 St Genés Champenelle, France
| | - Coraline Airault
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France
| | - Bernadette Félix
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France; INRA U1189, Département AlimH, 63122 St Genés Champenelle, France
| | - André Jean
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France
| | - Bruno Lebrun
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France
| | - Jean-Denis Troadec
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France.
| | - Michel Dallaporta
- EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, FST St Jérôme. Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, 13013 Marseille, France.
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Yamashita M, Takayanagi Y, Yoshida M, Nishimori K, Kusama M, Onaka T. Involvement of prolactin-releasing peptide in the activation of oxytocin neurones in response to food intake. J Neuroendocrinol 2013; 25:455-65. [PMID: 23363338 PMCID: PMC3664423 DOI: 10.1111/jne.12019] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 12/10/2012] [Accepted: 12/26/2012] [Indexed: 12/16/2022]
Abstract
Food intake activates neurones expressing prolactin-releasing peptide (PrRP) in the medulla oblongata and oxytocin neurones in the hypothalamus. Both PrRP and oxytocin have been shown to have an anorexic action. In the present study, we investigated whether the activation of oxytocin neurones following food intake is mediated by PrRP. We first examined the expression of PrRP receptors (also known as GPR10) in rats. Immunoreactivity of PrRP receptors was observed in oxytocin neurones and in vasopressin neurones in the paraventricular and supraoptic nuclei of the hypothalamus and in the bed nucleus of the stria terminalis. Application of PrRP to isolated supraoptic nuclei facilitated the release of oxytocin and vasopressin. In mice, re-feeding increased the expression of Fos protein in oxytocin neurones of the hypothalamus and bed nucleus of the stria terminalis. The increased expression of Fos protein in oxytocin neurones following re-feeding or i.p. administration of cholecystokinin octapeptide (CCK), a peripheral satiety factor, was impaired in PrRP-deficient mice. CCK-induced oxytocin increase in plasma was also impaired in PrRP-deficient mice. Furthermore, oxytocin receptor-deficient mice showed an increased meal size, as reported in PrRP-deficient mice and in CCKA receptor-deficient mice. These findings suggest that PrRP mediates, at least in part, the activation of oxytocin neurones in response to food intake, and that the CCK-PrRP-oxytocin pathway plays an important role in the control of the termination of each meal.
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Affiliation(s)
- M Yamashita
- Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, Shimotsuke-shi, Japan
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18
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Singru PS, Wittmann G, Farkas E, Zséli G, Fekete C, Lechan RM. Refeeding-activated glutamatergic neurons in the hypothalamic paraventricular nucleus (PVN) mediate effects of melanocortin signaling in the nucleus tractus solitarius (NTS). Endocrinology 2012; 153:3804-14. [PMID: 22700769 PMCID: PMC3404351 DOI: 10.1210/en.2012-1235] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We previously demonstrated that refeeding after a prolonged fast activates a subset of neurons in the ventral parvocellular subdivision of the paraventricular nucleus (PVNv) as a result of increased melanocortin signaling. To determine whether these neurons contribute to satiety by projecting to the nucleus tractus solitarius (NTS), the retrogradely transported marker substance, cholera toxin-β (CTB), was injected into the dorsal vagal complex of rats that were subsequently fasted and refed for 2 h. By double-labeling immunohistochemistry, CTB accumulation was found in the cytoplasm of the majority of refeeding-activated c-Fos neurons in the ventral parvocellular subdivision of the hypothalamic paraventricular nucleus (PVNv). In addition, a large number of refeeding-activated c-Fos-expressing neurons were observed in the lateral parvocellular subdivision (PVNl) that also contained CTB and were innervated by axon terminals of proopiomelanocortin neurons. To visualize the location of neuronal activation within the NTS by melanocortin-activated PVN neurons, α-MSH was focally injected into the PVN, resulting in an increased number of c-Fos-containing neurons in the PVN and in the NTS, primarily in the medial and commissural parts. All refeeding-activated neurons in the PVNv and PVNl expressed the mRNA of the glutamatergic marker, type 2 vesicular glutamate transporter (VGLUT2), indicating their glutamatergic phenotype, but only rare neurons contained oxytocin. These data suggest that melanocortin-activated neurons in the PVNv and PVNl may contribute to refeeding-induced satiety through effects on the NTS and may alter the sensitivity of NTS neurons to vagal satiety inputs via glutamate excitation.
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Affiliation(s)
- Praful S Singru
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Tufts Medical Center, no. 268, 800 Washington Street, Boston, Massachusetts 02111, USA
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Renner E, Puskás N, Dobolyi A, Palkovits M. Glucagon-like peptide-1 of brainstem origin activates dorsomedial hypothalamic neurons in satiated rats. Peptides 2012; 35:14-22. [PMID: 22401907 DOI: 10.1016/j.peptides.2012.02.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 02/21/2012] [Accepted: 02/21/2012] [Indexed: 01/01/2023]
Abstract
A high number of neurons express c-fos in response to unlimited food intake in fasted rats in the ventral subdivision of the hypothalamic dorsomedial nucleus (DMHv). We report here, that in same conditions, limited food consumption failed to induce Fos expression in DMHv neurons suggesting that satiation should be one of the important signals that activate these neurons. The possible origin of fibers conducting satiation signals to the DMHv could be in the lower brainstem, especially glucagon-like peptide-1 (GLP-1)-containing neurons in the nucleus of the solitary tract (NTS). We demonstrate that GLP-1-immunoreactive fibers and fiber terminals topographically overlap with activated Fos-positive neurons in the DMHv in refed rats. Using immunocytochemistry and in situ hybridization histochemistry, we demonstrated GLP-1 receptors in Fos-expressing neurons of the DMH. Unilateral transections of ascending GLP-1-containing fibers from the NTS inside the pons in refed rats (unlimited food consumption) resulted in a dramatic decrease in the density of GLP-1 fibers and in the number of Fos-immunoreactive neurons in the DMHv, but only on the side of the transection. Contralateral to the transection, neither the GLP-1 fiber density nor the number of Fos-positive cells changed significantly. Meanwhile, the density of GLP-1 immunoreactivity was markedly accumulated in transected nerve fibers caudal to the cuts, as a consequence of the interruption of the ascending GLP-1 transport route. These findings suggest that the solitary-hypothalamic projections may represent the neuronal route through GLP-1 neurons of the NTS activate DMHv neurons via GLP-1 receptors by conveying information on satiety.
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Affiliation(s)
- E Renner
- Neuromorphological and Neuroendocrine Research Laboratory, Department of Anatomy, Semmelweis University, Budapest H-1094, Hungary
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20
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Lucio-Oliveira F, Franci CR. Effect of the interaction between food state and the action of estrogen on oxytocinergic system activity. J Endocrinol 2012; 212:129-38. [PMID: 22083216 DOI: 10.1530/joe-11-0272] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Increased plasma osmolality by food intake evokes augmentation of plasma oxytocin (OT). Ovarian steroids may also influence the balance of body fluids by acting on OT neurones. Our aim was to determine if estrogen influences the activity of OT neurones in paraventricular nucleus (PVN) and supraoptic nucleus (SON) under different osmotic situations. Ovariectomized rats (OVX) were treated with either estradiol (E(2)) or vehicle and were divided into three groups: group I was fed ad libitum, group II underwent 48 h of fasting, and group III was refed after 48 h of fasting. On the day of the experiment, blood samples were collected to determine the plasma osmolality and OT. The animals were subsequently perfused, and OT/FOS immunofluorescence analysis was conducted on neurones in the PVN and the SON. When compared to animals which were fasted or fed ad libitum, the plasma osmolality of refed animals was higher, regardless of whether they were treated with vehicle or E(2). We observed neural activation of OT cells in vehicle- or E(2)-treated OVX rats refed after 48 h of fasting, but not in animals fed ad libitum or in animals that only underwent 48 h of fasting. Finally, the percentage of neurones that co-expressed OT and FOS was lower in both the PVN and the SON of animals treated with E(2) and refed, when compared to vehicle-treated animals. These results suggest that E(2) may have an inhibitory effect on OT neurones and may modulate the secretion of OT in response to the increase of osmolality induced by refeeding.
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Affiliation(s)
- F Lucio-Oliveira
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto - SP, Brazil
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Hypothalamic expression of urocortin 3 and the type 2 corticotropin-releasing factor receptor is regulated according to feeding state in lean but not obese Zucker rats. Neuropharmacology 2011; 63:147-53. [PMID: 22227020 DOI: 10.1016/j.neuropharm.2011.12.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/15/2011] [Accepted: 12/20/2011] [Indexed: 11/23/2022]
Abstract
Urocortin 3 (Ucn3) is an anorexigenic neuropeptide with high affinity for the type 2 corticotropin-releasing factor receptor (CRF₂-R). How the expression of hypothalamic Ucn3 is regulated by fasting and refeeding in genetically obese (fa/fa) Zucker rats is not known. Obese Zucker rats develop early hyperphagia associated with low expression of CRF₂-R in the ventromedial hypothalamic nucleus (VMH) in this phenotype. Although lean (Fa/?) Zucker rats have strong basal expression of CRF₂-R in the VMH, and normally consume less food compared to their obese littermates, at the beginning of refeeding, the lean rats ingested almost the same amount of food as the obese animals. The present study was designed to investigate the dynamics of the expression of CRF₂-R and Ucn3 in the brain of lean and obese Zucker rats fed ad libitum, food-deprived for 48 h, or refed for 1 and 24 h. The levels of expression of Ucn3 mRNA were analyzed in the rostral perifornical hypothalamus (rPFH) and dorsal medial amygdala (MeD), and CRF₂-R mRNA in the VMH and lateral septum (LS) using in situ hybridization. The results showed that in the ad libitum-fed state, both phenotypes had comparable levels of expression of rPFH Ucn3, but the obese rats had lower levels of expression of VMH CRF₂-R. Food deprivation decreased hypothalamic expression of Ucn3 and CRF₂-R in lean but not obese rats. One hour of refeeding triggered expression of rPFH Ucn3 but not VMH CRF₂-R in lean rats, and at 24 h of refeeding the levels of hypothalamic expression of Ucn3 and CRF₂-R returned to those seen in the ad libitum-fed state in both phenotypes. In the LS, the levels of expression of CRF₂-R were not affected by feeding and phenotype. In the MeD, the Ucn3 transcript increased by food deprivation in obese but not lean rats. Therefore, the increase of Ucn3 expression in the MeD in obese food-deprived rats may reflect stronger behavioral effects of food deprivation in this phenotype. The hypothalamic expression of Ucn3 and CRF₂)-R was modulated by the feeding states in lean but not obese rats. The low levels of VMH CRF₂-R may limit anorexigenic Ucn3 effects in the obese phenotype. The low VMH CRF₂-R levels at the beginning of refeeding in lean rats may allow them to ingest a considerable amount of food regardless of the rapidly increased expression of rPFH Ucn3 by refeeding in this phenotype. This article is part of a Special Issue entitled 'Central Control of Food Intake'.
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Girardet C, Bonnet MS, Jdir R, Sadoud M, Thirion S, Tardivel C, Roux J, Lebrun B, Wanaverbecq N, Mounien L, Trouslard J, Jean A, Dallaporta M, Troadec JD. The food-contaminant deoxynivalenol modifies eating by targeting anorexigenic neurocircuitry. PLoS One 2011; 6:e26134. [PMID: 22022538 PMCID: PMC3192137 DOI: 10.1371/journal.pone.0026134] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 09/20/2011] [Indexed: 01/25/2023] Open
Abstract
Physiological regulations of energy balance and body weight imply highly adaptive mechanisms which match caloric intake to caloric expenditure. In the central nervous system, the regulation of appetite relies on complex neurocircuitry which disturbance may alter energy balance and result in anorexia or obesity. Deoxynivalenol (DON), a trichothecene, is one of the most abundant mycotoxins found on contaminated cereals and its stability during processing and cooking explains its widespread presence in human food. DON has been implicated in acute and chronic illnesses in both humans and farm animals including weight loss. Here, we provide the first demonstration that DON reduced feeding behavior and modified satiation and satiety by interfering with central neuronal networks dedicated to food intake regulation. Moreover, our results strongly suggest that during intoxication, DON reaches the brain where it modifies anorexigenic balance. In view of the widespread human exposure to DON, the present results may lead to reconsider the potential consequences of chronic DON consumption on human eating disorders.
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Affiliation(s)
- Clémence Girardet
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Marion S. Bonnet
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Rajae Jdir
- Université Paul Cézanne, Marseille, France
| | | | - Sylvie Thirion
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
- Université de la Méditerranée, Marseille, France
| | - Catherine Tardivel
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Julien Roux
- Biomeostasis, Contract Research Organization, Marseille, France
| | - Bruno Lebrun
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Nicolas Wanaverbecq
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Lourdes Mounien
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Jérôme Trouslard
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - André Jean
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Michel Dallaporta
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
| | - Jean-Denis Troadec
- Université Paul Cézanne, Marseille, France
- INRA USC 2027, Marseille, France
- CNRS UMR 6231, Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, Département de Physiologie Neurovégétative, Marseille, France
- * E-mail:
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Baraboi ED, St-Pierre DH, Shooner J, Timofeeva E, Richard D. Brain activation following peripheral administration of the GLP-1 receptor agonist exendin-4. Am J Physiol Regul Integr Comp Physiol 2011; 301:R1011-24. [DOI: 10.1152/ajpregu.00424.2010] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The aim of our study was to investigate the anorectic and brain stimulatory effects of various doses of exendin-4 (Ex-4) and to investigate the role of the vagus nerve in Ex-4-induced brain activation. A dose-related increase in c- fos mRNA expression was observed following Ex-4 administration (0.155–15.5 μg/kg). Doses of Ex-4 that caused anorexia without aversive effects (0.155, 0.775 μg/kg) induced c- fos expression in the hypothalamic arcuate and paraventricular (PVH; parvocellular) nuclei as well as in the limbic and brainstem structures. Doses of Ex-4 that caused aversion (1.55, 15.5 μg/kg) stimulated the same regions (in a more intense way) and additionally activated the magnocellular hypothalamic structures (supraoptic nucleus and PVH magnocellular). The brain c- fos pattern induced by Ex-4 showed both similarities and differences with that induced by refeeding. Subdiaphragmatic vagotomy significantly blunted the stimulation of c- fos mRNA expression induced by Ex-4 in the nodose ganglion, the medial part of nucleus of the solitary tract, and the parvocellular division of the PVH. Pretreatment with Ex-9-39 (330 μg/kg ip) impaired the neuronal activation evoked by Ex-4 in all brain regions and in the nodose ganglion. Effects of Ex-4 on hypothalamic-pituitary-adrenal axis activity were not altered by vagotomy. Results of this study demonstrate and relate the anorectic and brain stimulatory effects of aversive and nonaversive doses of Ex-4 and indicate that the activation of specific central regions induced by the peripheral administration of Ex-4 is, at least in part, dependent on the integrity of the vagus nerve.
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Affiliation(s)
- Elena-Dana Baraboi
- Merck-Frosst/Canadian Institutes of Health Research Chair in Obesity and Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - David H. St-Pierre
- Merck-Frosst/Canadian Institutes of Health Research Chair in Obesity and Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Julie Shooner
- Merck-Frosst/Canadian Institutes of Health Research Chair in Obesity and Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Elena Timofeeva
- Merck-Frosst/Canadian Institutes of Health Research Chair in Obesity and Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Denis Richard
- Merck-Frosst/Canadian Institutes of Health Research Chair in Obesity and Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
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Mitra A, Lenglos C, Martin J, Mbende N, Gagné A, Timofeeva E. Sucrose modifies c-fos mRNA expression in the brain of rats maintained on feeding schedules. Neuroscience 2011; 192:459-74. [PMID: 21718761 DOI: 10.1016/j.neuroscience.2011.06.033] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 05/19/2011] [Accepted: 06/10/2011] [Indexed: 11/25/2022]
Abstract
Food intake is regulated according to circadian activity, metabolic needs and the hedonic value of food. Rodents placed on a fixed feeding schedule show behavioral and physiological anticipation of mealtime referred to as food-anticipatory activity (FAA). FAA is driven by the food-entrainable oscillator (FEO), whose anatomical substrate is not yet known. Recent data have shown that restricted feeding schedules for regular chow and daily limited access to palatable food in free-feeding rats activate distinct brain regions during FAA. The combination of a deprivation regimen and scheduled access to palatable food may give rise to a more global anticipatory mechanism because the temporal cycles of energy balance would be strongly modulated by the incentive properties of palatable food; however, the neuronal response to this combined treatment is not yet known. The present study investigated how adding palatable sucrose to feeding schedules affects the pattern of brain c-fos mRNA expression during FAA (0-3 h) and 1 h following feeding. The rats maintained on scheduled chow access increased their daily chow intake, while the rats maintained on scheduled sucrose and chow mainly increased their daily sucrose intake. Adding sucrose to scheduled feeding displaced c-fos mRNA expression from the dorsomedial and paraventricular hypothalamic nuclei and posterior lateral hypothalamus (LH) to the prefrontal cortex, lateral septum, nucleus accumbens and anterior LH. During refeeding, the rats on scheduled sucrose demonstrated higher activation of the nucleus of the solitary tract. The present results suggest that palatable sucrose combined with restricted feeding schedules activate a distinct neuronal network compared to neuronal activation produced by scheduled access to regular chow. These data provide evidence that the brain may contain different food-oscillatory systems and that food palatability may shift the neuronal activity from the medial hypothalamus to the limbic and reward-related areas even at the negative metabolic state.
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Affiliation(s)
- A Mitra
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Faculty of Medicine, Department of Psychiatry and Neuroscience, Université Laval, Québec (QC), G1V 4G5, Canada
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25
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Baraboi ED, Michel C, Smith P, Thibaudeau K, Ferguson AV, Richard D. Effects of albumin-conjugated PYY on food intake: the respective roles of the circumventricular organs and vagus nerve. Eur J Neurosci 2010; 32:826-39. [DOI: 10.1111/j.1460-9568.2010.07318.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Watanabe RLH, Andrade IS, Zemdegs JCS, Albuquerque KT, Nascimento CMO, Oyama LM, Carmo MGT, Nogueira MI, Ribeiro EB. Prolonged consumption of soy or fish-oil-enriched diets differentially affects the pattern of hypothalamic neuronal activation induced by refeeding in rats. Nutr Neurosci 2010; 12:242-8. [PMID: 19925717 DOI: 10.1179/147683009x423472] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
We used c-Fos immunoreactivity to estimate neuronal activation in hypothalamic feeding-regulatory areas of 3-month-old rats fed control or oil-enriched diets (soy or fish) since weaning. While no diet effect was observed in c-Fos immunoreactivity of 24-h fasted animals, the acute response to refeeding was modified by both hyperlipidic diets but with different patterns. Upon refeeding, control-diet rats had significantly increased c-Fos immunoreactivity only in the paraventricular hypothalamic nucleus (PVH, 142%). In soy-diet rats, refeeding with the soy diet increased c-Fos immunoreactivity in dorsomedial hypothalamic nucleus (DMH, 271%) and lateral hypothalamic area (LH, 303%). Refeeding fish-diet rats with the fish diet increased c-Fos immunoreactivity in PVH (161%), DMH (177%), VMH (81%), and ARC (127%). Compared to the fish-diet, c-Fos immunoreactivity was increased in LH by the soy-diet while it was decreased in ventromedial hypothalamic nucleus (VMH) and arcuate hypothalamic nucleus (ARC). Based on the known roles of the activated nuclei, it is suggested that, unlike the fish-diet, the soy-diet induced a potentially obesogenic profile, with high LH and low VMH/PVH activation after refeeding.
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Affiliation(s)
- Regina L H Watanabe
- Dept of Physiology, Division of Nutrition Physiology, Federal University of São Paulo, 04023-060 São Paulo, Brazil
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Renner E, Szabó-Meltzer KI, Puskás N, Tóth ZE, Dobolyi A, Palkovits M. Activation of neurons in the hypothalamic dorsomedial nucleus via hypothalamic projections of the nucleus of the solitary tract following refeeding of fasted rats. Eur J Neurosci 2010; 31:302-14. [PMID: 20074225 DOI: 10.1111/j.1460-9568.2009.07053.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We report that satiation evokes neuronal activity in the ventral subdivision of the hypothalamic dorsomedial nucleus (DMH) as indicated by increased c-fos expression in response to refeeding in fasted rats. The absence of significant Fos activation following food presentation without consumption suggests that satiation but not craving for food elicits the activation of ventral DMH neurons. The distribution pattern of the prolactin-releasing peptide (PrRP)-immunoreactive (ir) network showed remarkable correlations with the distribution of activated neurons within the DMH. The PrRP-ir fibers and terminals were immunolabeled with tyrosine hydroxylase, suggesting their origin in lower brainstem instead of local, hypothalamic PrRP cells. PrRP-ir fibers arising from neurons of the nucleus of the solitary tract could be followed to the hypothalamus. Unilateral transections of these fibers at pontine and caudal hypothalamic levels resulted in a disappearance of the dense PrRP-ir network in the ventral DMH while PrRP immunoreactivity was increased in transected fibers caudal to the knife cuts as well as in perikarya of the nucleus of the solitary tract ipsilateral to the transections. In accord with these changes, the number of Fos-expressing neurons following refeeding declined in the ipsilateral but remained high in the contralateral DMH. However, the Fos response in the ventral DMH was not attenuated following chemical lesion (neonatal monosodium glutamate treatment) of the hypothalamic arcuate nucleus, another possible source of DMH inputs. These findings suggest that PrRP projections from the nucleus of the solitary tract contribute to the activation of ventral DMH neurons during refeeding, possibly by transferring information on cholecystokinin-mediated satiation.
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Affiliation(s)
- Eva Renner
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
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Uchoa ET, Mendes da Silva LEC, de Castro M, Antunes-Rodrigues J, Elias LLK. Hypothalamic oxytocin neurons modulate hypophagic effect induced by adrenalectomy. Horm Behav 2009; 56:532-8. [PMID: 19778539 DOI: 10.1016/j.yhbeh.2009.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 09/04/2009] [Accepted: 09/13/2009] [Indexed: 10/20/2022]
Abstract
Glucocorticoids have major effects on food intake, as demonstrated by the decrease of food intake following adrenalectomy (ADX); however, the mechanisms leading to these effects are not well understood. Oxytocin (OT) has been shown to reduce food intake. We evaluated the effects of glucocorticoids on OT neuron activation and OT mRNA expression in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei induced by feeding. We also evaluated the effect of pretreatment with OT-receptor antagonist ([d(CH2)5,Tyr(Me)2,Orn8]-vasotocin, OVT) on food intake in ADX rats. Fos/OT neurons in the posterior parvocellular subdivision of the PVN were increased after refeeding, with a higher number in the ADX group, compared with sham and ADX+corticosterone (B) groups, with no difference in the medial parvocellular and magnocellular subdivisions of the PVN. ADX increased OT mRNA expression in the PVN both in fasting and refeeding condition, compared with sham and ADX+B groups. In the SON, refeeding increased the number of Fos/OT neurons, with a higher number in the ADX+B group. In fasted condition, OT mRNA expression in the SON was increased in ADX and ADX+B, compared with sham group. Pretreatment with OVT reversed the ADX-induced hypophagia, with no difference between sham and ADX+B animals. The present results show that glucocorticoid withdrawal induces a higher activation of PVN OT neurons in response to feeding, and an increase of OT mRNA expression in the PVN and OT-receptor antagonist reverses the anorexigenic effect induced by ADX. These data indicate that PVN OT neurons might mediate the hypophagic effect induced by adrenalectomy.
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Affiliation(s)
- Ernane Torres Uchoa
- Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, São Paulo, Brazil
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Uchoa ET, Sabino HAC, Ruginsk SG, Antunes-Rodrigues J, Elias LLK. Hypophagia induced by glucocorticoid deficiency is associated with an increased activation of satiety-related responses. J Appl Physiol (1985) 2008; 106:596-604. [PMID: 19023022 DOI: 10.1152/japplphysiol.90865.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glucocorticoids have major effects on food intake, demonstrated by the decrease of food intake following adrenalectomy. Satiety signals are relayed to the nucleus of the solitary tract (NTS), which has reciprocal projections with the arcuate nucleus (ARC) and paraventricular nucleus (PVN) of the hypothalamus. We evaluated the effects of glucocorticoids on the activation of hypothalamic and NTS neurons induced by food intake in rats subjected to adrenalectomy (ADX) or sham surgery 7 days before the experiments. One-half of ADX animals received corticosterone (ADX+B) in the drinking water (B: 25 mg/l). Fos/tyrosine hydroxylase (TH), Fos/corticotrophin-releasing factor (CRF) and Fos immunoreactivity were assessed in the NTS, PVN, and ARC, respectively. Food intake and body weight were reduced in the ADX group compared with sham and ADX+B groups. Fos and Fos/TH in the NTS, Fos, and Fos/CRF immunoreactive neurons in the PVN and Fos in the ARC were increased after refeeding, with higher number in the ADX group, compared with sham and ADX+B groups. CCK administration showed no hypophagic effect on ADX group despite a similar increase of Fos/TH immunoreactive neurons in the NTS compared with sham and ADX+B groups, suggesting that CCK alone cannot further increase the anorexigenic effect induced by glucocorticoid deficiency. The present data indicate that glucocorticoid withdrawal reduced food intake, which was associated with higher activation of ARC, CRF neurons of the PVN, and catecholaminergic neurons of the NTS. In the absence of glucocorticoids, satiety signals elicited during a meal lead to an augmented activation of brain stem and hypothalamic pathways.
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Poulin AM, Timofeeva E. The dynamics of neuronal activation during food anticipation and feeding in the brain of food-entrained rats. Brain Res 2008; 1227:128-41. [DOI: 10.1016/j.brainres.2008.06.039] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Revised: 04/04/2008] [Accepted: 06/15/2008] [Indexed: 02/04/2023]
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Sabbatini M, Molinari C, Grossini E, Piffanelli V, Mary DASG, Vacca G, Cannas M. GABAA receptors expression pattern in rat brain following low pressure distension of the stomach. Neuroscience 2008; 152:449-58. [PMID: 18280049 DOI: 10.1016/j.neuroscience.2008.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 12/17/2007] [Accepted: 01/10/2008] [Indexed: 11/19/2022]
Abstract
It is known that gastric mechanoreceptor stimuli are widely integrated into neuronal circuits that involve visceral nuclei of hindbrain as well as several central brain areas. GABAergic neurons are widely represented in hindbrain nuclei controlling gastric motor functions, but limited information is available specifically about GABA(A)-responding neurons in brain visceral areas. The present investigation was designed to determine the central sensory neuronal pathways and their GABA(A)-alpha1 and -alpha3 receptor presenting neurons that respond to gastric mechanoreceptor stimulation within the entire rat brain. Low pressure gastric distension was used to deliver physiological mechanical stimuli in anesthetized rats, and different protocols of gastric distension were performed to mimic different stimulation patterns with and without sectioning vagal and/or splanchnic afferent nerves. Mapping of activated neurons was investigated using double colorimetric immunohistochemistry for GABA(A)-alpha1 or -alpha3 subunits and c-Fos. Following stomach distension, neurons expressing GABA(A) receptors with alpha1 or alpha3 subunits were detected. Low frequency gastric distension induced c-Fos expression in nucleus tractus solitarii (NTS) only, whereas in the high frequency gastric distension c-Fos positive nuclei were found in lateral reticular nucleus and in NTS in addition to some forebrain areas. In contrast, during the tonic-rapid gastric distension the neuronal activation was found in hindbrain, midbrain and forebrain areas. Moreover different protocols of gastric stimulation activated diverse patterns of neurons presenting GABA(A)-alpha1 or -alpha3 receptors within responding brain nuclei, which may indicate a probable functional significance of differential expression of GABA(A)-responding neurons. The same protocol of gastric distension performed in vagotomized rats has confirmed the primary role of the vagus in the response of activation of gastric brain areas, whereas neuronal input of splanchnic origins was shown to play an important role in modulating the mechanogastric response of brain areas.
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Affiliation(s)
- M Sabbatini
- Laboratorio di Anatomia Umana, Dipartimento Medicina Clinica e Sperimentale, Università del Piemonte Orientale, Novara, Italy.
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Kohno D, Nakata M, Maejima Y, Shimizu H, Sedbazar U, Yoshida N, Dezaki K, Onaka T, Mori M, Yada T. Nesfatin-1 neurons in paraventricular and supraoptic nuclei of the rat hypothalamus coexpress oxytocin and vasopressin and are activated by refeeding. Endocrinology 2008; 149:1295-301. [PMID: 18048495 DOI: 10.1210/en.2007-1276] [Citation(s) in RCA: 203] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nesfatin-1, a newly discovered satiety molecule, is located in the hypothalamic nuclei, including the paraventricular nucleus (PVN) and supraoptic nucleus (SON). In this study, fine localization and regulation of nesfatin-1 neurons in the PVN and SON were investigated by immunohistochemistry of neuropeptides and c-Fos. In the PVN, 24% of nesfatin-1 neurons overlapped with oxytocin, 18% with vasopressin, 13% with CRH, and 12% with TRH neurons. In the SON, 35% of nesfatin-1 neurons overlapped with oxytocin and 28% with vasopressin. After a 48-h fast, refeeding for 2 h dramatically increased the number of nesfatin-1 neurons expressing c-Fos immunoreactivity by approximately 10 times in the PVN and 30 times in the SON, compared with the fasting controls. In the SON, refeeding also significantly increased the number of nesfatin-1-immunoreactive neurons and NUCB2 mRNA expression, compared with fasting. These results indicate that nesfatin-1 neurons in the PVN and SON highly overlap with oxytocin and vasopressin neurons and that they are activated markedly by refeeding. Feeding-activated nesfatin-1 neurons in the PVN and SON could play a role in the postprandial regulation of feeding behavior and energy homeostasis.
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Affiliation(s)
- Daisuke Kohno
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University, School of Medicine, Tochigi 329-0498, Japan
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Knapska E, Radwanska K, Werka T, Kaczmarek L. Functional internal complexity of amygdala: focus on gene activity mapping after behavioral training and drugs of abuse. Physiol Rev 2007; 87:1113-73. [PMID: 17928582 DOI: 10.1152/physrev.00037.2006] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The amygdala is a heterogeneous brain structure implicated in processing of emotions and storing the emotional aspects of memories. Gene activity markers such as c-Fos have been shown to reflect both neuronal activation and neuronal plasticity. Herein, we analyze the expression patterns of gene activity markers in the amygdala in response to either behavioral training or treatment with drugs of abuse and then we confront the results with data on other approaches to internal complexity of the amygdala. c-Fos has been the most often studied in the amygdala, showing specific expression patterns in response to various treatments, most probably reflecting functional specializations among amygdala subdivisions. In the basolateral amygdala, c-Fos expression appears to be consistent with the proposed role of this nucleus in a plasticity of the current stimulus-value associations. Within the medial part of the central amygdala, c-Fos correlates with acquisition of alimentary/gustatory behaviors. On the other hand, in the lateral subdivision of the central amygdala, c-Fos expression relates to attention and vigilance. In the medial amygdala, c-Fos appears to be evoked by emotional novelty of the experimental situation. The data on the other major subdivisions of the amygdala are scarce. In conclusion, the studies on the gene activity markers, confronted with other approaches involving neuroanatomy, physiology, and the lesion method, have revealed novel aspects of the amygdala, especially pointing to functional heterogeneity of this brain region that does not fit very well into contemporarily active debate on serial versus parallel information processing within the amygdala.
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Singru PS, Sánchez E, Fekete C, Lechan RM. Importance of melanocortin signaling in refeeding-induced neuronal activation and satiety. Endocrinology 2007; 148:638-46. [PMID: 17068131 DOI: 10.1210/en.2006-1233] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To identify regions in the hypothalamus involved in refeeding and their regulation by alpha-MSH, adult rats were subjected to a 3-d fast, and 2 h after refeeding, the distribution of c-Fos-immunoreactive neurons was elucidated. Compared with fed and fasted animals, a significant increase (P < 0.001) in the number of c-Fos-immunoreactive cells was identified in refed animals in the supraoptic nucleus, magnocellular and ventral parvocellular subdivisions of the hypothalamic paraventricular nucleus (PVNv), and the dorsal and ventral subdivisions of the dorsomedial nucleus (DMNd and DMNv, respectively). Refeeding shifted the location of c-Fos-labeled neurons from the medial to lateral arcuate where c-Fos was induced in 88.7 +/- 2.2% of alpha-MSH-containing neurons. alpha-MSH-containing axons densely innervated the PVNv, DMNd, and DMNv and organized in close apposition to the majority of refeeding-activated c-Fos-positive neurons. To test whether the melanocortin system is involved in induction of c-Fos in these regions, the melanocortin 3/4 receptor antagonist, agouti-related protein (AGRP 83-132), was administered to fasting animals just before refeeding. Compared with artificial cerebrospinal fluid, a single intracerebroventricular bolus of agouti-related protein (5 microg/5 microl) not only significantly increased the total amount of food consumed within 2 h but also nearly abolished refeeding-induced c-Fos expression in the PVNv and DMNd and partially reduced c-Fos immunoreactivity in the DMNv. We conclude that refeeding activates a subset of neurons in the PVN and DMN as a result of increased melanocortin signaling and propose that one or more of these neuronal populations mediate the potent anorexic actions of alpha-MSH.
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Affiliation(s)
- Praful S Singru
- Professor of Medicine, Division of Endocrinology, Box No. 268, New England Medical Center, 750 Washington Street, Boston, Massachusetts 02111, USA
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Coppola A, Liu ZW, Andrews ZB, Paradis E, Roy MC, Friedman JM, Ricquier D, Richard D, Horvath TL, Gao XB, Diano S. A central thermogenic-like mechanism in feeding regulation: an interplay between arcuate nucleus T3 and UCP2. Cell Metab 2007; 5:21-33. [PMID: 17189204 PMCID: PMC1783766 DOI: 10.1016/j.cmet.2006.12.002] [Citation(s) in RCA: 233] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 10/26/2006] [Accepted: 12/07/2006] [Indexed: 01/09/2023]
Abstract
The active thyroid hormone, triiodothyronine (T3), regulates mitochondrial uncoupling protein activity and related thermogenesis in peripheral tissues. Type 2 deiodinase (DII), an enzyme that catalyzes active thyroid hormone production, and mitochondrial uncoupling protein 2 (UCP2) are also present in the hypothalamic arcuate nucleus, where their interaction and physiological significance have not been explored. Here, we report that DII-producing glial cells are in direct apposition to neurons coexpressing neuropeptide Y (NPY), agouti-related protein (AgRP), and UCP2. Fasting increased DII activity and local thyroid hormone production in the arcuate nucleus in parallel with increased GDP-regulated UCP2-dependent mitochondrial uncoupling. Fasting-induced T3-mediated UCP2 activation resulted in mitochondrial proliferation in NPY/AgRP neurons, an event that was critical for increased excitability of these orexigenic neurons and consequent rebound feeding following food deprivation. These results reveal a physiological role for a thyroid-hormone-regulated mitochondrial uncoupling in hypothalamic neuronal networks.
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Affiliation(s)
- Anna Coppola
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
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