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Aimé P, Hegoburu C, Jaillard T, Degletagne C, Garcia S, Messaoudi B, Thevenet M, Lorsignol A, Duchamp C, Mouly AM, Julliard AK. A physiological increase of insulin in the olfactory bulb decreases detection of a learned aversive odor and abolishes food odor-induced sniffing behavior in rats. PLoS One 2012; 7:e51227. [PMID: 23251461 PMCID: PMC3522659 DOI: 10.1371/journal.pone.0051227] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 10/30/2012] [Indexed: 11/19/2022] Open
Abstract
Insulin is involved in multiple regulatory mechanisms, including body weight and food intake, and plays a critical role in metabolic disorders such as obesity and diabetes. An increasing body of evidence indicates that insulin is also involved in the modulation of olfactory function. The olfactory bulb (OB) contains the highest level of insulin and insulin receptors (IRs) in the brain. However, a role for insulin in odor detection and sniffing behavior remains to be elucidated. Using a behavioral paradigm based on conditioned olfactory aversion (COA) to isoamyl-acetate odor, we demonstrated that an intracerebroventricular (ICV) injection of 14 mU insulin acutely decreased olfactory detection of fasted rats to the level observed in satiated animals. In addition, whereas fasted animals demonstrated an increase in respiratory frequency upon food odor detection, this effect was absent in fasted animals receiving a 14 mU insulin ICV injection as well as in satiated animals. In parallel, we showed that the OB and plasma insulin levels were increased in satiated rats compared to fasted rats, and that a 14 mU insulin ICV injection elevated the OB insulin level of fasted rats to that of satiated rats. We further quantified insulin receptors (IRs) distribution and showed that IRs are preferentially expressed in the caudal and lateral parts of the main OB, with the highest labeling found in the mitral cells, the main OB projection neurons. Together, these data suggest that insulin acts on the OB network to modulate olfactory processing and demonstrate that olfactory function is under the control of signals involved in energy homeostasis regulation and feeding behaviors.
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Affiliation(s)
- Pascaline Aimé
- Centre de Recherche en Neurosciences de Lyon (CRNL), Team Olfaction: From Coding to Memory, CNRS UMR 5292 - INSERM U1028- Université Lyon1 - Université de Lyon, Lyon, France
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, United States of America
| | - Chloé Hegoburu
- Centre de Recherche en Neurosciences de Lyon (CRNL), Team Olfaction: From Coding to Memory, CNRS UMR 5292 - INSERM U1028- Université Lyon1 - Université de Lyon, Lyon, France
| | - Tristan Jaillard
- Métabolisme Plasticité Mitochondrie, CNRS UMR 5241 - Université Paul Sabatier, Toulouse, France
- STROMALab, CNRS UMR 5273 - EFS - INSERM U1031- Université Paul Sabatier, Toulouse, France
| | - Cyril Degletagne
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), CNRS UMR 5023 - Université Lyon 1 – Université de Lyon, Villeurbanne, France
| | - Samuel Garcia
- Centre de Recherche en Neurosciences de Lyon (CRNL), Team Olfaction: From Coding to Memory, CNRS UMR 5292 - INSERM U1028- Université Lyon1 - Université de Lyon, Lyon, France
| | - Belkacem Messaoudi
- Centre de Recherche en Neurosciences de Lyon (CRNL), Team Olfaction: From Coding to Memory, CNRS UMR 5292 - INSERM U1028- Université Lyon1 - Université de Lyon, Lyon, France
| | - Marc Thevenet
- Centre de Recherche en Neurosciences de Lyon (CRNL), Team Olfaction: From Coding to Memory, CNRS UMR 5292 - INSERM U1028- Université Lyon1 - Université de Lyon, Lyon, France
| | - Anne Lorsignol
- Métabolisme Plasticité Mitochondrie, CNRS UMR 5241 - Université Paul Sabatier, Toulouse, France
- STROMALab, CNRS UMR 5273 - EFS - INSERM U1031- Université Paul Sabatier, Toulouse, France
| | - Claude Duchamp
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), CNRS UMR 5023 - Université Lyon 1 – Université de Lyon, Villeurbanne, France
| | - Anne-Marie Mouly
- Centre de Recherche en Neurosciences de Lyon (CRNL), Team Olfaction: From Coding to Memory, CNRS UMR 5292 - INSERM U1028- Université Lyon1 - Université de Lyon, Lyon, France
| | - Andrée Karyn Julliard
- Centre de Recherche en Neurosciences de Lyon (CRNL), Team Olfaction: From Coding to Memory, CNRS UMR 5292 - INSERM U1028- Université Lyon1 - Université de Lyon, Lyon, France
- * E-mail:
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Colombani AL, Carneiro L, Benani A, Galinier A, Jaillard T, Duparc T, Offer G, Lorsignol A, Magnan C, Casteilla L, Pénicaud L, Leloup C. Enhanced hypothalamic glucose sensing in obesity: alteration of redox signaling. Diabetes 2009; 58:2189-97. [PMID: 19581415 PMCID: PMC2750216 DOI: 10.2337/db09-0110] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Recent data demonstrated that glucose sensing in different tissues is initiated by an intracellular redox signaling pathway in physiological conditions. However, the relevance of such a mechanism in metabolic disease is not known. The aim of the present study was to determine whether brain glucose hypersensitivity present in obese Zücker rats is related to an alteration in redox signaling. RESEARCH DESIGN AND METHODS Brain glucose sensing alteration was investigated in vivo through the evaluation of electrical activity in arcuate nucleus, changes in reactive oxygen species levels, and hypothalamic glucose-induced insulin secretion. In basal conditions, modifications of redox state and mitochondrial functions were assessed through oxidized glutathione, glutathione peroxidase, manganese superoxide dismutase, aconitase activities, and mitochondrial respiration. RESULTS Hypothalamic hypersensitivity to glucose was characterized by enhanced electrical activity of the arcuate nucleus and increased insulin secretion at a low glucose concentration, which does not produce such an effect in normal rats. It was associated with 1) increased reactive oxygen species levels in response to this low glucose load, 2) constitutive oxidized environment coupled with lower antioxidant enzyme activity at both the cellular and mitochondrial level, and 3) overexpression of several mitochondrial subunits of the respiratory chain coupled with a global dysfunction in mitochondrial activity. Moreover, pharmacological restoration of the glutathione hypothalamic redox state by reduced glutathione infusion in the third ventricle fully reversed the cerebral hypersensitivity to glucose. CONCLUSIONS The data demonstrated that obese Zücker rats' impaired hypothalamic regulation in terms of glucose sensing is linked to an abnormal redox signaling, which originates from mitochondria dysfunction.
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Affiliation(s)
- Anne-Laure Colombani
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Lionel Carneiro
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Alexandre Benani
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Anne Galinier
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Tristan Jaillard
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Thibaut Duparc
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Géraldine Offer
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Anne Lorsignol
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Christophe Magnan
- Physiopathologie de la Nutrition, Unité Mixte de Recherche 7059, Centre National de la Recherche Scientifique, Université Denis Diderot, Paris, France
| | - Louis Casteilla
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Luc Pénicaud
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Corinne Leloup
- Métabolisme, Plasticité et Mitochondrie, Unité Mixte de Recherche 5241, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
- Corresponding author: Corinne Leloup,
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Jaillard T, Roger M, Galinier A, Guillou P, Benani A, Leloup C, Casteilla L, Pénicaud L, Lorsignol A. Hypothalamic reactive oxygen species are required for insulin-induced food intake inhibition: an NADPH oxidase-dependent mechanism. Diabetes 2009; 58:1544-9. [PMID: 19389827 PMCID: PMC2699877 DOI: 10.2337/db08-1039] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 03/26/2009] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Insulin plays an important role in the hypothalamic control of energy balance, especially by reducing food intake. Emerging data point to a pivotal role of reactive oxygen species (ROS) in energy homeostasis regulation, but their involvement in the anorexigenic effect of insulin is unknown. Furthermore, ROS signal derived from NADPH oxidase activation is required for physiological insulin effects in peripheral cells. In this study, we investigated the involvement of hypothalamic ROS and NADPH oxidase in the feeding behavior regulation by insulin. RESEARCH DESIGN AND METHODS We first measured hypothalamic ROS levels and food intake after acute intracerebroventricular injection of insulin. Second, effect of pretreatment with a ROS scavenger or an NADPH oxidase inhibitor was evaluated. Third, we examined the consequences of two nutritional conditions of central insulin unresponsiveness (fasting or short-term high-fat diet) on the ability of insulin to modify ROS level and food intake. RESULTS In normal chow-fed mice, insulin inhibited food intake. At the same dose, insulin rapidly and transiently increased hypothalamic ROS levels by 36%. The pharmacological suppression of this insulin-stimulated ROS elevation, either by antioxidant or by an NADPH oxidase inhibitor, abolished the anorexigenic effect of insulin. Finally, in fasted and short-term high-fat diet-fed mice, insulin did not promote elevation of ROS level and food intake inhibition, likely because of an increase in hypothalamic diet-induced antioxidant defense systems. CONCLUSIONS A hypothalamic ROS increase through NADPH oxidase is required for the anorexigenic effect of insulin.
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Affiliation(s)
- Tristan Jaillard
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Michael Roger
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Anne Galinier
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Pascale Guillou
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Alexandre Benani
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Corinne Leloup
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Louis Casteilla
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Luc Pénicaud
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
| | - Anne Lorsignol
- Université de Toulouse, UPS, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5241 Métabolisme, Plasticité et Mitochondrie, Toulouse, France
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Jaillard T, Roger M, Guillou P, Benani A, Casteilla L, Penicaud L, Lorsignol A. Insulin differently modulates hypothalamic mitochondrial energy metabolism in fed or fasted mice: Involvement in food intake regulation? Appetite 2008. [DOI: 10.1016/j.appet.2008.04.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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