Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker rats
Objectives: Hypothalamic lipotoxicity has been shown to induce central insulin resistance and dysregulation of glucose homeostasis; nevertheless, elucidation of the regulatory mechanisms remains incomplete. Here, we aimed to determine the role of de novo ceramide synthesis in hypothalamus on the ons...
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2018-02-01
|
| Series: | Molecular Metabolism |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2212877817306907 |
| _version_ | 1818022992697884672 |
|---|---|
| author | Mélanie Campana Lara Bellini Claude Rouch Latif Rachdi Nicolas Coant Noémie Butin Cécile L. Bandet Erwann Philippe Kelly Meneyrol Nadim Kassis Julien Dairou Eric Hajduch Benoit Colsch Christophe Magnan Hervé Le Stunff |
| author_facet | Mélanie Campana Lara Bellini Claude Rouch Latif Rachdi Nicolas Coant Noémie Butin Cécile L. Bandet Erwann Philippe Kelly Meneyrol Nadim Kassis Julien Dairou Eric Hajduch Benoit Colsch Christophe Magnan Hervé Le Stunff |
| author_sort | Mélanie Campana |
| collection | DOAJ |
| description | Objectives: Hypothalamic lipotoxicity has been shown to induce central insulin resistance and dysregulation of glucose homeostasis; nevertheless, elucidation of the regulatory mechanisms remains incomplete. Here, we aimed to determine the role of de novo ceramide synthesis in hypothalamus on the onset of central insulin resistance and the dysregulation of glucose homeostasis induced by obesity. Methods: Hypothalamic GT1-7 neuronal cells were treated with palmitate. De novo ceramide synthesis was inhibited either by pharmacological (myriocin) or molecular (si-Serine Palmitoyl Transferase 2, siSPT2) approaches. Obese Zucker rats (OZR) were intracerebroventricularly infused with myriocin to inhibit de novo ceramide synthesis. Insulin resistance was determined by quantification of Akt phosphorylation. Ceramide levels were quantified either by a radioactive kinase assay or by mass spectrometry analysis. Glucose homeostasis were evaluated in myriocin-treated OZR. Basal and glucose-stimulated parasympathetic tonus was recorded in OZR. Insulin secretion from islets and β-cell mass was also determined. Results: We show that palmitate impaired insulin signaling and increased ceramide levels in hypothalamic neuronal GT1-7 cells. In addition, the use of deuterated palmitic acid demonstrated that palmitate activated several enzymes of the de novo ceramide synthesis pathway in hypothalamic cells. Importantly, myriocin and siSPT2 treatment restored insulin signaling in palmitate-treated GT1-7 cells. Protein kinase C (PKC) inhibitor or a dominant-negative PKCζ also counteracted palmitate-induced insulin resistance. Interestingly, attenuating the increase in levels of hypothalamic ceramides with intracerebroventricular infusion of myriocin in OZR improved their hypothalamic insulin-sensitivity. Importantly, central myriocin treatment partially restored glucose tolerance in OZR. This latter effect is related to the restoration of glucose-stimulated insulin secretion and an increase in β-cell mass of OZR. Electrophysiological recordings also showed an improvement of glucose-stimulated parasympathetic nerve activity in OZR centrally treated with myriocin. Conclusion: Our results highlight a key role of hypothalamic de novo ceramide synthesis in central insulin resistance installation and glucose homeostasis dysregulation associated with obesity. Keywords: Ceramide, Lipotoxicity, Hypotalamus, Insulin resistance, Insulin secretion |
| first_indexed | 2024-12-10T03:37:14Z |
| format | Article |
| id | doaj.art-36162c8527874fe1a2f4d78629f38b0c |
| institution | Directory Open Access Journal |
| issn | 2212-8778 |
| language | English |
| last_indexed | 2024-12-10T03:37:14Z |
| publishDate | 2018-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Molecular Metabolism |
| spelling | doaj.art-36162c8527874fe1a2f4d78629f38b0c2022-12-22T02:03:40ZengElsevierMolecular Metabolism2212-87782018-02-0182336Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker ratsMélanie Campana0Lara Bellini1Claude Rouch2Latif Rachdi3Nicolas Coant4Noémie Butin5Cécile L. Bandet6Erwann Philippe7Kelly Meneyrol8Nadim Kassis9Julien Dairou10Eric Hajduch11Benoit Colsch12Christophe Magnan13Hervé Le Stunff14Sorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceINSERM U1016, Université Paris-Descartes, Institut Cochin, Paris, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceCEA, DRF, Institut Joliot, Service de Pharmacologie et d'Immunoanalyse, UMR 0496, Laboratoire d'Etude du Métabolisme des Médicaments, MetaboHUB, Université Paris Saclay, F-91191 Gif-sur-Yvette cedex, FranceINSERM U1138, Centre de Recherche des Cordeliers, Paris, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceLaboratoire de Chimie et Biochimie Pharmacologique et Toxicologiques, Université Paris Descartes CNRS UMR 8601, Paris, FranceINSERM U1138, Centre de Recherche des Cordeliers, Paris, FranceCEA, DRF, Institut Joliot, Service de Pharmacologie et d'Immunoanalyse, UMR 0496, Laboratoire d'Etude du Métabolisme des Médicaments, MetaboHUB, Université Paris Saclay, F-91191 Gif-sur-Yvette cedex, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, FranceSorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Bâtiment Buffon, PO box 7126, 4, rue Marie-Andrée Lagroua Weill-Halle, 75205 Paris Cedex 13, France; Molecular Neuroendocrinology of Food intake, Neuroscience Paris-Saclay Institute (NeuroPSI), UMR 9197, Université Paris-Sud, France; Corresponding author. Unité Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Équipe Régulation de la glycémie par le système nerveux central, Université Paris Diderot, Paris, France.Objectives: Hypothalamic lipotoxicity has been shown to induce central insulin resistance and dysregulation of glucose homeostasis; nevertheless, elucidation of the regulatory mechanisms remains incomplete. Here, we aimed to determine the role of de novo ceramide synthesis in hypothalamus on the onset of central insulin resistance and the dysregulation of glucose homeostasis induced by obesity. Methods: Hypothalamic GT1-7 neuronal cells were treated with palmitate. De novo ceramide synthesis was inhibited either by pharmacological (myriocin) or molecular (si-Serine Palmitoyl Transferase 2, siSPT2) approaches. Obese Zucker rats (OZR) were intracerebroventricularly infused with myriocin to inhibit de novo ceramide synthesis. Insulin resistance was determined by quantification of Akt phosphorylation. Ceramide levels were quantified either by a radioactive kinase assay or by mass spectrometry analysis. Glucose homeostasis were evaluated in myriocin-treated OZR. Basal and glucose-stimulated parasympathetic tonus was recorded in OZR. Insulin secretion from islets and β-cell mass was also determined. Results: We show that palmitate impaired insulin signaling and increased ceramide levels in hypothalamic neuronal GT1-7 cells. In addition, the use of deuterated palmitic acid demonstrated that palmitate activated several enzymes of the de novo ceramide synthesis pathway in hypothalamic cells. Importantly, myriocin and siSPT2 treatment restored insulin signaling in palmitate-treated GT1-7 cells. Protein kinase C (PKC) inhibitor or a dominant-negative PKCζ also counteracted palmitate-induced insulin resistance. Interestingly, attenuating the increase in levels of hypothalamic ceramides with intracerebroventricular infusion of myriocin in OZR improved their hypothalamic insulin-sensitivity. Importantly, central myriocin treatment partially restored glucose tolerance in OZR. This latter effect is related to the restoration of glucose-stimulated insulin secretion and an increase in β-cell mass of OZR. Electrophysiological recordings also showed an improvement of glucose-stimulated parasympathetic nerve activity in OZR centrally treated with myriocin. Conclusion: Our results highlight a key role of hypothalamic de novo ceramide synthesis in central insulin resistance installation and glucose homeostasis dysregulation associated with obesity. Keywords: Ceramide, Lipotoxicity, Hypotalamus, Insulin resistance, Insulin secretionhttp://www.sciencedirect.com/science/article/pii/S2212877817306907 |
| spellingShingle | Mélanie Campana Lara Bellini Claude Rouch Latif Rachdi Nicolas Coant Noémie Butin Cécile L. Bandet Erwann Philippe Kelly Meneyrol Nadim Kassis Julien Dairou Eric Hajduch Benoit Colsch Christophe Magnan Hervé Le Stunff Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker rats Molecular Metabolism |
| title | Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker rats |
| title_full | Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker rats |
| title_fullStr | Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker rats |
| title_full_unstemmed | Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker rats |
| title_short | Inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β-cell function of obese Zucker rats |
| title_sort | inhibition of central de novo ceramide synthesis restores insulin signaling in hypothalamus and enhances β cell function of obese zucker rats |
| url | http://www.sciencedirect.com/science/article/pii/S2212877817306907 |
| work_keys_str_mv | AT melaniecampana inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT larabellini inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT clauderouch inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT latifrachdi inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT nicolascoant inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT noemiebutin inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT cecilelbandet inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT erwannphilippe inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT kellymeneyrol inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT nadimkassis inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT juliendairou inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT erichajduch inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT benoitcolsch inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT christophemagnan inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats AT hervelestunff inhibitionofcentraldenovoceramidesynthesisrestoresinsulinsignalinginhypothalamusandenhancesbcellfunctionofobesezuckerrats |