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Smith MA, Choudhury AI, Glegola JA, Viskaitis P, Irvine EE, de Campos Silva PCC, Khadayate S, Zeilhofer HU, Withers DJ. Extrahypothalamic GABAergic nociceptin-expressing neurons regulate AgRP neuron activity to control feeding behavior. J Clin Invest 2020; 130:126-142. [PMID: 31557134 PMCID: PMC6934207 DOI: 10.1172/jci130340] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/19/2019] [Indexed: 12/15/2022] Open
Abstract
Arcuate nucleus agouti-related peptide (AgRP) neurons play a central role in feeding and are under complex regulation by both homeostatic hormonal and nutrient signals and hypothalamic neuronal pathways. Feeding may also be influenced by environmental cues, sensory inputs, and other behaviors, implying the involvement of higher brain regions. However, whether such pathways modulate feeding through direct synaptic control of AgRP neuron activity is unknown. Here, we show that nociceptin-expressing neurons in the anterior bed nuclei of the stria terminalis (aBNST) make direct GABAergic inputs onto AgRP neurons. We found that activation of these neurons inhibited AgRP neurons and feeding. The activity of these neurons increased upon food availability, and their ablation resulted in obesity. Furthermore, these neurons received afferent inputs from a range of upstream brain regions as well as hypothalamic nuclei. Therefore, aBNST GABAergic nociceptin neurons may act as a gateway to feeding behavior by connecting AgRP neurons to both homeostatic and nonhomeostatic neuronal inputs.
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Affiliation(s)
- Mark A. Smith
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College, London, United Kingdom
| | | | | | | | - Elaine E. Irvine
- MRC London Institute of Medical Sciences, London, United Kingdom
| | | | - Sanjay Khadayate
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Dominic J. Withers
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College, London, United Kingdom
- MRC London Institute of Medical Sciences, London, United Kingdom
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2
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Rached MT, Millership SJ, Pedroni SMA, Choudhury AI, Costa ASH, Hardy DG, Glegola JA, Irvine EE, Selman C, Woodberry MC, Yadav VK, Khadayate S, Vidal-Puig A, Virtue S, Frezza C, Withers DJ. Deletion of myeloid IRS2 enhances adipose tissue sympathetic nerve function and limits obesity. Mol Metab 2019; 20:38-50. [PMID: 30553769 PMCID: PMC6358539 DOI: 10.1016/j.molmet.2018.11.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/21/2018] [Accepted: 11/25/2018] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE Sympathetic nervous system and immune cell interactions play key roles in the regulation of metabolism. For example, recent convergent studies have shown that macrophages regulate obesity through brown adipose tissue (BAT) activation and beiging of white adipose tissue (WAT) via effects upon local catecholamine availability. However, these studies have raised issues about the underlying mechanisms involved including questions regarding the production of catecholamines by macrophages, the role of macrophage polarization state and the underlying intracellular signaling pathways in macrophages that might mediate these effects. METHODS To address such issues we generated mice lacking Irs2, which mediates the effects of insulin and interleukin 4, specifically in LyzM expressing cells (Irs2LyzM-/- mice). RESULTS These animals displayed obesity resistance and preservation of glucose homeostasis on high fat diet feeding due to increased energy expenditure via enhanced BAT activity and WAT beiging. Macrophages per se did not produce catecholamines but Irs2LyzM-/- mice displayed increased sympathetic nerve density and catecholamine availability in adipose tissue. Irs2-deficient macrophages displayed an anti-inflammatory transcriptional profile and alterations in genes involved in scavenging catecholamines and supporting increased sympathetic innervation. CONCLUSIONS Our studies identify a critical macrophage signaling pathway involved in the regulation of adipose tissue sympathetic nerve function that, in turn, mediates key neuroimmune effects upon systemic metabolism. The insights gained may open therapeutic opportunities for the treatment of obesity.
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Affiliation(s)
- Marie-Therese Rached
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Steven J Millership
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Silvia M A Pedroni
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | | | - Ana S H Costa
- MRC Cancer Unit, University of Cambridge, Box 197, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK
| | - Darran G Hardy
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Justyna A Glegola
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Elaine E Irvine
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Megan C Woodberry
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Vijay K Yadav
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK; Department of Genetics and Development, Columbia University, New York, 10032, USA
| | - Sanjay Khadayate
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Antonio Vidal-Puig
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK; University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, CB2 0QQ, UK
| | - Samuel Virtue
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, CB2 0QQ, UK
| | - Christian Frezza
- MRC Cancer Unit, University of Cambridge, Box 197, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
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Millership SJ, Tunster SJ, Van de Pette M, Choudhury AI, Irvine EE, Christian M, Fisher AG, John RM, Scott J, Withers DJ. Neuronatin deletion causes postnatal growth restriction and adult obesity in 129S2/Sv mice. Mol Metab 2018; 18:97-106. [PMID: 30279096 PMCID: PMC6308027 DOI: 10.1016/j.molmet.2018.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 09/10/2018] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVE Imprinted genes are crucial for the growth and development of fetal and juvenile mammals. Altered imprinted gene dosage causes a variety of human disorders, with growth and development during these crucial early stages strongly linked with future metabolic health in adulthood. Neuronatin (Nnat) is a paternally expressed imprinted gene found in neuroendocrine systems and white adipose tissue and is regulated by the diet and leptin. Neuronatin expression is downregulated in obese children and has been associated with stochastic obesity in C57BL/6 mice. However, our recent studies of Nnat null mice on this genetic background failed to display any body weight or feeding phenotypes but revealed a defect in glucose-stimulated insulin secretion due to the ability of neuronatin to potentiate signal peptidase cleavage of preproinsulin. Nnat deficiency in beta cells therefore caused a lack of appropriate storage and secretion of mature insulin. METHODS To further explore the potential role of Nnat in the regulation of body weight and adiposity, we studied classical imprinting-related phenotypes such as placental, fetal, and postnatal growth trajectory patterns that may impact upon subsequent adult metabolic phenotypes. RESULTS Here we find that, in contrast to the lack of any body weight or feeding phenotypes on the C57BL/6J background, deletion of Nnat in mice on 129S2/Sv background causes a postnatal growth restriction with reduced adipose tissue accumulation, followed by catch up growth after weaning. This was in the absence of any effect on fetal growth or placental development. In adult 129S2/Sv mice, Nnat deletion was associated with hyperphagia, reduced energy expenditure, and partial leptin resistance. Lack of neuronatin also potentiated obesity caused by either aging or high fat diet feeding. CONCLUSIONS The imprinted gene Nnat plays a key role in postnatal growth, adult energy homeostasis, and the pathogenesis of obesity via catch up growth effects, but this role is dependent upon genetic background.
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Affiliation(s)
- Steven J Millership
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Simon J Tunster
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | | | | | - Elaine E Irvine
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Mark Christian
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Amanda G Fisher
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Rosalind M John
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - James Scott
- National Heart and Lung Institute, Department of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
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Smith MA, Katsouri L, Virtue S, Choudhury AI, Vidal-Puig A, Ashford MLJ, Withers DJ. Calcium Channel Ca V2.3 Subunits Regulate Hepatic Glucose Production by Modulating Leptin-Induced Excitation of Arcuate Pro-opiomelanocortin Neurons. Cell Rep 2018; 25:278-287.e4. [PMID: 30304668 PMCID: PMC6198286 DOI: 10.1016/j.celrep.2018.09.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/26/2018] [Accepted: 09/07/2018] [Indexed: 11/18/2022] Open
Abstract
Leptin acts on hypothalamic pro-opiomelanocortin (POMC) neurons to regulate glucose homeostasis, but the precise mechanisms remain unclear. Here, we demonstrate that leptin-induced depolarization of POMC neurons is associated with the augmentation of a voltage-gated calcium (CaV) conductance with the properties of the "R-type" channel. Knockdown of the pore-forming subunit of the R-type (CaV2.3 or Cacna1e) conductance in hypothalamic POMC neurons prevented sustained leptin-induced depolarization. In vivo POMC-specific Cacna1e knockdown increased hepatic glucose production and insulin resistance, while body weight, feeding, or leptin-induced suppression of food intake were not changed. These findings link Cacna1e function to leptin-mediated POMC neuron excitability and glucose homeostasis and may provide a target for the treatment of diabetes.
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Affiliation(s)
- Mark A Smith
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK.
| | - Loukia Katsouri
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK
| | - Samuel Virtue
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Agharul I Choudhury
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Michael L J Ashford
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Dominic J Withers
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK; Institute of Clinical Sciences, Imperial College London, Du Cane Road, London W12 0NN, UK.
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5
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Millership SJ, Da Silva Xavier G, Choudhury AI, Bertazzo S, Chabosseau P, Pedroni SM, Irvine EE, Montoya A, Faull P, Taylor WR, Kerr-Conte J, Pattou F, Ferrer J, Christian M, John RM, Latreille M, Liu M, Rutter GA, Scott J, Withers DJ. Neuronatin regulates pancreatic β cell insulin content and secretion. J Clin Invest 2018; 128:3369-3381. [PMID: 29864031 PMCID: PMC6063487 DOI: 10.1172/jci120115] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 05/17/2018] [Indexed: 02/06/2023] Open
Abstract
Neuronatin (Nnat) is an imprinted gene implicated in human obesity and widely expressed in neuroendocrine and metabolic tissues in a hormone- and nutrient-sensitive manner. However, its molecular and cellular functions and precise role in organismal physiology remain only partly defined. Here we demonstrate that mice lacking Nnat globally or specifically in β cells display impaired glucose-stimulated insulin secretion leading to defective glucose handling under conditions of nutrient excess. In contrast, we report no evidence for any feeding or body weight phenotypes in global Nnat-null mice. At the molecular level neuronatin augments insulin signal peptide cleavage by binding to the signal peptidase complex and facilitates translocation of the nascent preprohormone. Loss of neuronatin expression in β cells therefore reduces insulin content and blunts glucose-stimulated insulin secretion. Nnat expression, in turn, is glucose-regulated. This mechanism therefore represents a novel site of nutrient-sensitive control of β cell function and whole-animal glucose homeostasis. These data also suggest a potential wider role for Nnat in the regulation of metabolism through the modulation of peptide processing events.
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Affiliation(s)
- Steven J. Millership
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Gabriela Da Silva Xavier
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | | | - Sergio Bertazzo
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Pauline Chabosseau
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Silvia M.A. Pedroni
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Elaine E. Irvine
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - Alex Montoya
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - Peter Faull
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - William R. Taylor
- Computational Cell and Molecular Biology Laboratory, Francis Crick Institute, London, United Kingdom
| | - Julie Kerr-Conte
- European Genomic Institute for Diabetes, UMR 1190 Translational Research for Diabetes, INSERM, CHU Lille, University of Lille, Lille, France
| | - Francois Pattou
- European Genomic Institute for Diabetes, UMR 1190 Translational Research for Diabetes, INSERM, CHU Lille, University of Lille, Lille, France
| | - Jorge Ferrer
- Beta Cell Genome Regulation Laboratory, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mark Christian
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Rosalind M. John
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - James Scott
- National Heart and Lung Institute, Department of Medicine, Imperial College London, London, United Kingdom
| | - Dominic J. Withers
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
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6
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Viskaitis P, Irvine EE, Smith MA, Choudhury AI, Alvarez-Curto E, Glegola JA, Hardy DG, Pedroni SMA, Paiva Pessoa MR, Fernando ABP, Katsouri L, Sardini A, Ungless MA, Milligan G, Withers DJ. Modulation of SF1 Neuron Activity Coordinately Regulates Both Feeding Behavior and Associated Emotional States. Cell Rep 2018; 21:3559-3572. [PMID: 29262334 PMCID: PMC5746599 DOI: 10.1016/j.celrep.2017.11.089] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/18/2017] [Accepted: 11/27/2017] [Indexed: 12/24/2022] Open
Abstract
Feeding requires the integration of homeostatic drives with emotional states relevant to food procurement in potentially hostile environments. The ventromedial hypothalamus (VMH) regulates feeding and anxiety, but how these are controlled in a concerted manner remains unclear. Using pharmacogenetic, optogenetic, and calcium imaging approaches with a battery of behavioral assays, we demonstrate that VMH steroidogenic factor 1 (SF1) neurons constitute a nutritionally sensitive switch, modulating the competing motivations of feeding and avoidance of potentially dangerous environments. Acute alteration of SF1 neuronal activity alters food intake via changes in appetite and feeding-related behaviors, including locomotion, exploration, anxiety, and valence. In turn, intrinsic SF1 neuron activity is low during feeding and increases with both feeding termination and stress. Our findings identify SF1 neurons as a key part of the neurocircuitry that controls both feeding and related affective states, giving potential insights into the relationship between disordered eating and stress-associated psychological disorders in humans.
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Affiliation(s)
- Paulius Viskaitis
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Elaine E Irvine
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Mark A Smith
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Agharul I Choudhury
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Elisa Alvarez-Curto
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Justyna A Glegola
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Darran G Hardy
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Silvia M A Pedroni
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Maria R Paiva Pessoa
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Anushka B P Fernando
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Loukia Katsouri
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Alessandro Sardini
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Mark A Ungless
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK.
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Rahman MG, Choudhury AI, Sakeb N, Islam KM, Karim R, Ali MY, Yiasmeen S. Evaluation of the outcome of replacement hemiarthroplasty by uncemented bipolar prosthesis in displaced fracture neck femur. Mymensingh Med J 2014; 23:461-470. [PMID: 25178597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Despite continued discussion regarding the treatment of displaced femoral neck fractures, controversies continue regarding their optimal treatment, including the choice of implant and fixation method. Hemiarthroplasty is one of the option which eliminate concerns about fixation failure, nonunion, and avascular necrosis and has become the choice of surgery among the aged >60. This prospective interventional study was carried out on 28 cases at the Department of Orthopaedic Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), from July 2009 to April 2012 to evaluate cementless, bipolar prosthesis among the active elderly patients. All subjects were evaluated with regard to postoperative clinical, functional and activity outcome (Modified Harris Hip Scoring and Hip Outcome Scoring), intra and post operative complications. One case was dropped from follow up and 22(81.48%) patients were considered to have satisfactory outcome after statistical analysis by chi-square test on at least 12 months follow up records. Although prosthetic stem valgus and periprosthetic fracture developed in 02 cases and 01 patient had sunken prosthesis, uncemented bipolar hemiarthroplasty can give significantly good functional outcomes with minimal complications for displaced intracapsular femoral neck fracture in active elderly patients.
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Affiliation(s)
- M G Rahman
- Dr Md Golam Rahman, Assistant Professor, Department of Orthopaedic Surgery, Shahabuddin Medical College, Gulshan, Dhaka, Bangladesh
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8
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Karra E, O'Daly OG, Choudhury AI, Yousseif A, Millership S, Neary MT, Scott WR, Chandarana K, Manning S, Hess ME, Iwakura H, Akamizu T, Millet Q, Gelegen C, Drew ME, Rahman S, Emmanuel JJ, Williams SCR, Rüther UU, Brüning JC, Withers DJ, Zelaya FO, Batterham RL. A link between FTO, ghrelin, and impaired brain food-cue responsivity. J Clin Invest 2013; 123:3539-51. [PMID: 23867619 DOI: 10.1172/jci44403] [Citation(s) in RCA: 256] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 05/17/2013] [Indexed: 12/15/2022] Open
Abstract
Polymorphisms in the fat mass and obesity-associated gene (FTO) are associated with human obesity and obesity-prone behaviors, including increased food intake and a preference for energy-dense foods. FTO demethylates N6-methyladenosine, a potential regulatory RNA modification, but the mechanisms by which FTO predisposes humans to obesity remain unclear. In adiposity-matched, normal-weight humans, we showed that subjects homozygous for the FTO "obesity-risk" rs9939609 A allele have dysregulated circulating levels of the orexigenic hormone acyl-ghrelin and attenuated postprandial appetite reduction. Using functional MRI (fMRI) in normal-weight AA and TT humans, we found that the FTO genotype modulates the neural responses to food images in homeostatic and brain reward regions. Furthermore, AA and TT subjects exhibited divergent neural responsiveness to circulating acyl-ghrelin within brain regions that regulate appetite, reward processing, and incentive motivation. In cell models, FTO overexpression reduced ghrelin mRNA N6-methyladenosine methylation, concomitantly increasing ghrelin mRNA and peptide levels. Furthermore, peripheral blood cells from AA human subjects exhibited increased FTO mRNA, reduced ghrelin mRNA N6-methyladenosine methylation, and increased ghrelin mRNA abundance compared with TT subjects. Our findings show that FTO regulates ghrelin, a key mediator of ingestive behavior, and offer insight into how FTO obesity-risk alleles predispose to increased energy intake and obesity in humans.
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Affiliation(s)
- Efthimia Karra
- Centre for Obesity Research, University College London, London, United Kingdom
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9
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Chandarana K, Gelegen C, Irvine EE, Choudhury AI, Amouyal C, Andreelli F, Withers DJ, Batterham RL. Peripheral activation of the Y2-receptor promotes secretion of GLP-1 and improves glucose tolerance. Mol Metab 2013; 2:142-52. [PMID: 24049729 DOI: 10.1016/j.molmet.2013.03.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 03/04/2013] [Accepted: 03/05/2013] [Indexed: 12/15/2022] Open
Abstract
The effect of peptide tyrosine-tyrosine (PYY) on feeding is well established but currently its role in glucose homeostasis is poorly defined. Here we show in mice, that intraperitoneal (ip) injection of PYY3-36 or Y2R agonist improves nutrient-stimulated glucose tolerance and enhances insulin secretion; an effect blocked by peripheral, but not central, Y2R antagonist administration. Studies on isolated mouse islets revealed no direct effect of PYY3-36 on insulin secretion. Bariatric surgery in mice, enterogastric anastomosis (EGA), improved glucose tolerance in wild-type mice and increased circulating PYY and active GLP-1. In contrast, in Pyy-null mice, post-operative glucose tolerance and active GLP-1 levels were similar in EGA and sham-operated groups. PYY3-36 ip increased hepato-portal active GLP-1 plasma levels, an effect blocked by ip Y2R antagonist. Collectively, these data suggest that PYY3-36 therefore acting via peripheral Y2R increases hepato-portal active GLP-1 plasma levels and improves nutrient-stimulated glucose tolerance.
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Key Words
- AUC, area under the curve
- CNS, central nervous system
- DPP-4, di-peptidyl peptidase-4
- EGA, entero-gastric anastomosis
- GLP-1
- Glucose homeostasis
- HFD, high-fat diet
- ICV, intracerebroventricular
- IPGTT, intraperitoneal glucose tolerance test
- PYY
- PYY, peptide tyrosine–tyrosine
- T2DM, type 2 diabetes mellitus
- WT, wild-type
- Y2-receptor
- Y2R, Y2-receptor
- aCSF, artificial cerebrospinal fluid
- active GLP-1, glucagon-like peptide-1(7-36)amide
- ip, intraperitoneal
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Affiliation(s)
- Keval Chandarana
- Centre for Obesity Research, Department of Medicine, University College London, Rayne Institute, 5 University Street, WC1E 6JJ, London, UK
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Costello DA, Claret M, Al-Qassab H, Plattner F, Irvine EE, Choudhury AI, Giese KP, Withers DJ, Pedarzani P. Brain deletion of insulin receptor substrate 2 disrupts hippocampal synaptic plasticity and metaplasticity. PLoS One 2012; 7:e31124. [PMID: 22383997 PMCID: PMC3287998 DOI: 10.1371/journal.pone.0031124] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 01/03/2012] [Indexed: 01/17/2023] Open
Abstract
Objective Diabetes mellitus is associated with cognitive deficits and an increased risk of dementia, particularly in the elderly. These deficits and the corresponding neurophysiological structural and functional alterations are linked to both metabolic and vascular changes, related to chronic hyperglycaemia, but probably also defects in insulin action in the brain. To elucidate the specific role of brain insulin signalling in neuronal functions that are relevant for cognitive processes we have investigated the behaviour of neurons and synaptic plasticity in the hippocampus of mice lacking the insulin receptor substrate protein 2 (IRS-2). Research Design and Methods To study neuronal function and synaptic plasticity in the absence of confounding factors such as hyperglycaemia, we used a mouse model with a central nervous system- (CNS)-restricted deletion of IRS-2 (NesCreIrs2KO). Results We report a deficit in NMDA receptor-dependent synaptic plasticity in the hippocampus of NesCreIrs2KO mice, with a concomitant loss of metaplasticity, the modulation of synaptic plasticity by the previous activity of a synapse. These plasticity changes are associated with reduced basal phosphorylation of the NMDA receptor subunit NR1 and of downstream targets of the PI3K pathway, the protein kinases Akt and GSK-3β. Conclusions These findings reveal molecular and cellular mechanisms that might underlie cognitive deficits linked to specific defects of neuronal insulin signalling.
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Affiliation(s)
- Derek A. Costello
- Research Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Marc Claret
- Department of Medicine, University College London, London, United Kingdom
| | - Hind Al-Qassab
- Department of Medicine, University College London, London, United Kingdom
| | - Florian Plattner
- Wolfson Institute of Biomedical Research, University College London, London, United Kingdom
| | - Elaine E. Irvine
- Department of Medicine, University College London, London, United Kingdom
- Wolfson Institute of Biomedical Research, University College London, London, United Kingdom
- Metabolic Signalling Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom
| | - Agharul I. Choudhury
- Department of Medicine, University College London, London, United Kingdom
- Metabolic Signalling Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom
| | - K. Peter Giese
- Wolfson Institute of Biomedical Research, University College London, London, United Kingdom
| | - Dominic J. Withers
- Department of Medicine, University College London, London, United Kingdom
- Metabolic Signalling Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom
| | - Paola Pedarzani
- Research Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- * E-mail:
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Irvine EE, Drinkwater L, Radwanska K, Al-Qassab H, Smith MA, O'Brien M, Kielar C, Choudhury AI, Krauss S, Cooper JD, Withers DJ, Giese KP. Insulin receptor substrate 2 is a negative regulator of memory formation. Learn Mem 2011; 18:375-83. [PMID: 21597043 DOI: 10.1101/lm.2111311] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Insulin has been shown to impact on learning and memory in both humans and animals, but the downstream signaling mechanisms involved are poorly characterized. Insulin receptor substrate-2 (Irs2) is an adaptor protein that couples activation of insulin- and insulin-like growth factor-1 receptors to downstream signaling pathways. Here, we have deleted Irs2, either in the whole brain or selectively in the forebrain, using the nestin Cre- or D6 Cre-deleter mouse lines, respectively. We show that brain- and forebrain-specific Irs2 knockout mice have enhanced hippocampal spatial reference memory. Furthermore, NesCreIrs2KO mice have enhanced spatial working memory and contextual- and cued-fear memory. Deletion of Irs2 in the brain also increases PSD-95 expression and the density of dendritic spines in hippocampal area CA1, possibly reflecting an increase in the number of excitatory synapses per neuron in the hippocampus that can become activated during memory formation. This increase in activated excitatory synapses might underlie the improved hippocampal memory formation observed in NesCreIrs2KO mice. Overall, these results suggest that Irs2 acts as a negative regulator on memory formation by restricting dendritic spine generation.
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Affiliation(s)
- Elaine E Irvine
- Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, United Kingdom
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12
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Chandarana K, Gelegen C, Karra E, Choudhury AI, Drew ME, Fauveau V, Viollet B, Andreelli F, Withers DJ, Batterham RL. Diet and gastrointestinal bypass-induced weight loss: the roles of ghrelin and peptide YY. Diabetes 2011; 60:810-8. [PMID: 21292870 PMCID: PMC3046841 DOI: 10.2337/db10-0566] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Bariatric surgery causes durable weight loss. Gut hormones are implicated in obesity pathogenesis, dietary failure, and mediating gastrointestinal bypass (GIBP) surgery weight loss. In mice, we determined the effects of diet-induced obesity (DIO), subsequent dieting, and GIBP surgery on ghrelin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). To evaluate PYY's role in mediating weight loss post-GIBP, we undertook GIBP surgery in PyyKO mice. RESEARCH DESIGN AND METHODS Male C57BL/6 mice randomized to a high-fat diet or control diet were killed at 4-week intervals. DIO mice underwent switch to ad libitum low-fat diet (DIO-switch) or caloric restriction (CR) for 4 weeks before being killed. PyyKO mice and their DIO wild-type (WT) littermates underwent GIBP or sham surgery and were culled 10 days postoperatively. Fasting acyl-ghrelin, total PYY, active GLP-1 concentrations, stomach ghrelin expression, and colonic Pyy and glucagon expression were determined. Fasting and postprandial PYY and GLP-1 concentrations were assessed 30 days postsurgery in GIBP and sham pair-fed (sham.PF) groups. RESULTS DIO progressively reduced circulating fasting acyl-ghrelin, PYY, and GLP-1 levels. CR and DIO-switch caused weight loss but failed to restore circulating PYY to weight-appropriate levels. After GIBP, WT mice lost weight and exhibited increased circulating fasting PYY and colonic Pyy and glucagon expression. In contrast, the acute effects of GIBP on body weight were lost in PyyKO mice. Fasting PYY and postprandial PYY and GLP-1 levels were increased in GIBP mice compared with sham.PF mice. CONCLUSIONS PYY plays a key role in mediating the early weight loss observed post-GIBP, whereas relative PYY deficiency during dieting may compromise weight-loss attempts.
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Affiliation(s)
- Keval Chandarana
- Centre for Obesity Research, Department of Medicine, University College London, Rayne Institute, London, U.K
| | - Cigdem Gelegen
- Centre for Obesity Research, Department of Medicine, University College London, Rayne Institute, London, U.K
| | - Efthimia Karra
- Centre for Obesity Research, Department of Medicine, University College London, Rayne Institute, London, U.K
| | - Agharul I. Choudhury
- Metabolic Signalling Group, Medical Research Council Clinical Sciences Centre, Imperial College, London, U.K
| | - Megan E. Drew
- Centre for Obesity Research, Department of Medicine, University College London, Rayne Institute, London, U.K
| | - Veronique Fauveau
- Institut Cochin, IFR Alfred Jost, Université Paris Descartes, Plate Forme de Microchirurgie, Faculté de Médecine Cochin, Paris, France
| | - Benoit Viollet
- Institut Cochin, Université Paris Descartes, Paris, France
- INSERM, Paris, France
- Centre National de la Recherche Scientifique, UMR 8104, Paris, France
| | - Fabrizio Andreelli
- Institut Cochin, Université Paris Descartes, Paris, France
- INSERM, Paris, France
| | - Dominic J. Withers
- Metabolic Signalling Group, Medical Research Council Clinical Sciences Centre, Imperial College, London, U.K
| | - Rachel L. Batterham
- Centre for Obesity Research, Department of Medicine, University College London, Rayne Institute, London, U.K
- Corresponding author: Rachel L. Batterham,
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13
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Datta NK, Kaiser MS, Saha BK, Ahammed SU, Choudhury AI. Baker's method in the management of equinus deformity in cerebral palsy. Mymensingh Med J 2010; 19:533-538. [PMID: 20956895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This prospective study was conducted in the department of orthopedic surgery in Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka, Bangladesh, from January 2005 to December 2007. Total number of 20 patients with 37 feet of equinus deformity due to cerebral palsy was managed by Baker's method. Equinus deformity in cerebral palsy is not uncommon in our outpatient department. Before operation patient walks on tip toes and after operation by Baker's method by apponeurotic lengthening of gastrocnemius muscle, with extensive physiotherapy, patients can able to walk normally in plantigrade feet. Among 20 patients only the spastic diplegic or hemiplegic equinus deformity in cerebral palsy was between 3 years to 12 years with a mean age of 5 years 9.6 months (SD+/-2 years 4.97 months). There were 3(15%) unilateral and 17(85%) bilateral cases. Among 20 cases, 13(65%) were male and 7(35%) were female. All cases were followed up for period ranging from 4 month to 28 months. Final clinical outcome was satisfactory (excellent and good) in 34(92%) feet and unsatisfactory (fair plus poor) in 3(8%) feet (p<0.001).
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Affiliation(s)
- N K Datta
- Department of Orthopaedic Surgery, Bangabandhu Sheik Mujib Medical University (BSMMU), Shahbagh, Dhaka, Bangladesh.
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Choudhury AI, Datta NK, Kaiser S, Tarafder WH, Das KP, Ahammed S. Management of old Tendo Achilles injury by surgical reconstruction with Lindholm technique. Mymensingh Med J 2010; 19:213-218. [PMID: 20395914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This prospective study was carried out in the department of orthopaedic surgery, Bangabandhu Sheikh Mujib Medical University from January 2006 to December 2007. Main aim of this study was to improve the power of planter flexion by reconstructive method with Lindholm technique to prevent walking disability. We had a study on 21 patients whose age range was 7 to 58 years. Mean age 34.19 years. Out of 21 cases male were 18(85.75%) and female were 3(14.25%). Chronocity of Tendo Achilles injury on average 2.64 (SD+/-1.08 month). Final clinical outcome of 21 cases 18 (85.75%) patients were satisfactory and 3(14.25%) were unsatisfactory. Lindholm technique is a good method of treatment for the management of Tendo Achilles injury was evident from this study. In Bangladesh toilet pan injury was more common. All patients were treated by surgical method of reconstruction by Lindholm technique.
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Affiliation(s)
- A I Choudhury
- Department of Orthopaedic Surgey, Bangabandhu Sheikh Mujib Medical University (BSMMU), Shahbagh, Dhaka, Bangladesh
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15
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Ara A, Khalil M, Sultana SZ, Ahmed MS, Akhter F, Haque N, Haque MA, Choudhury AI. Morphometric study of vocal fold of different sexes of Bangladeshi cadaver. Mymensingh Med J 2010; 19:173-175. [PMID: 20395907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The larynx is an organ of respiration and phonation. Larynx or Voice box is well developed in humans. The sound made by a human being using the vocal folds for talking, singing, laughing, crying, screaming etc. Pitch of the sound depends on the length, tension and mass of the vocal folds. This cross sectional descriptive type of study was done to see the length of the vocal folds and to establish the difference between sexes of adult Bangladeshi people. A total of 29 human larynges of adult age group ranging from 17 to 60 years in the both sexes were collected by purposive sampling during routine postmortem examination at the autopsy laboratory of Department of Forensic Medicine of Mymensingh Medical College, from October 2008 to March 2009. The mean length of vocal fold was measured and significance differences of the dimension between male and female were observed. In the present study observed finding was compared with those of other researchers. In male the mean(+/-SD) length of vocal fold was 23.12(+/-4.06) mm. In female the mean(+/-SD) length of vocal fold was 18.50(+/-2.39) mm. In statistical analysis, difference between male and female values was calculated by using Students (Unpaired) 't' test. The present study revealed that the value was greater in male than in female group and this difference was statistically significant (p<0.01).
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Affiliation(s)
- A Ara
- Department of Anatomy, Mymensingh Medical College, Mymensingh, Bangladesh
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16
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Al-Qassab H, Smith MA, Irvine EE, Guillermet-Guibert J, Claret M, Choudhury AI, Selman C, Piipari K, Clements M, Lingard S, Chandarana K, Bell JD, Barsh GS, Smith AJH, Batterham RL, Ashford MLJ, Vanhaesebroeck B, Withers DJ. Dominant role of the p110beta isoform of PI3K over p110alpha in energy homeostasis regulation by POMC and AgRP neurons. Cell Metab 2009; 10:343-54. [PMID: 19883613 PMCID: PMC2806524 DOI: 10.1016/j.cmet.2009.09.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2009] [Revised: 08/10/2009] [Accepted: 09/16/2009] [Indexed: 11/20/2022]
Abstract
PI3K signaling is thought to mediate leptin and insulin action in hypothalamic pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, through largely unknown mechanisms. We inactivated either p110alpha or p110beta PI3K catalytic subunits in these neurons and demonstrate a dominant role for the latter in energy homeostasis regulation. In POMC neurons, p110beta inactivation prevented insulin- and leptin-stimulated electrophysiological responses. POMCp110beta null mice exhibited central leptin resistance, increased adiposity, and diet-induced obesity. In contrast, the response to leptin was not blocked in p110alpha-deficient POMC neurons. Accordingly, POMCp110alpha null mice displayed minimal energy homeostasis abnormalities. Similarly, in AgRP neurons, p110beta had a more important role than p110alpha. AgRPp110alpha null mice displayed normal energy homeostasis regulation, whereas AgRPp110beta null mice were lean, with increased leptin sensitivity and resistance to diet-induced obesity. These results demonstrate distinct metabolic roles for the p110alpha and p110beta isoforms of PI3K in hypothalamic energy regulation.
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Affiliation(s)
- Hind Al-Qassab
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London WC1E 6JJ, UK
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17
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Selman C, Tullet JM, Wieser D, Irvine E, Lingard SJ, Choudhury AI, Claret M, Al-Qassab H, Carmignac D, Ramadani F, Woods A, Robinson IC, Schuster E, Batterham RL, Kozma SC, Thomas G, Carling D, Okkenhaug K, Thornton JM, Partridge L, Gems D, Withers DJ. Ribosomal protein S6 kinase 1 signaling regulates mammalian life span. Science 2009; 326:140-4. [PMID: 19797661 PMCID: PMC4954603 DOI: 10.1126/science.1177221] [Citation(s) in RCA: 843] [Impact Index Per Article: 56.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Caloric restriction (CR) protects against aging and disease, but the mechanisms by which this affects mammalian life span are unclear. We show in mice that deletion of ribosomal S6 protein kinase 1 (S6K1), a component of the nutrient-responsive mTOR (mammalian target of rapamycin) signaling pathway, led to increased life span and resistance to age-related pathologies, such as bone, immune, and motor dysfunction and loss of insulin sensitivity. Deletion of S6K1 induced gene expression patterns similar to those seen in CR or with pharmacological activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), a conserved regulator of the metabolic response to CR. Our results demonstrate that S6K1 influences healthy mammalian life-span and suggest that therapeutic manipulation of S6K1 and AMPK might mimic CR and could provide broad protection against diseases of aging.
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Affiliation(s)
- Colin Selman
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
| | - Jennifer M.A. Tullet
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, WC1E 6BT, UK
| | - Daniela Wieser
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Elaine Irvine
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
| | - Steven J. Lingard
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
| | - Agharul I. Choudhury
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
| | - Marc Claret
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
| | - Hind Al-Qassab
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
| | - Danielle Carmignac
- Division of Molecular Neuroendocrinology, Medical Research Council National Institute of Medical Research, London, NW7 1AA, UK
| | - Faruk Ramadani
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, CB22 3AT, UK
| | - Angela Woods
- Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College, London, W12 0NN, UK
| | - Iain C.A. Robinson
- Division of Molecular Neuroendocrinology, Medical Research Council National Institute of Medical Research, London, NW7 1AA, UK
| | - Eugene Schuster
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Rachel L. Batterham
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
| | - Sara C. Kozma
- Department of Cancer and Cell Biology, Genome Research Institute, University of Cincinnati, Cincinnati, OH 45237, USA
| | - George Thomas
- Department of Cancer and Cell Biology, Genome Research Institute, University of Cincinnati, Cincinnati, OH 45237, USA
| | - David Carling
- Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College, London, W12 0NN, UK
| | - Klaus Okkenhaug
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, CB22 3AT, UK
| | - Janet M. Thornton
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Linda Partridge
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, WC1E 6BT, UK
| | - David Gems
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, WC1E 6BT, UK
| | - Dominic J. Withers
- Institute of Healthy Ageing, Centre for Diabetes and Endocrinology, Department of Medicine, University College London, London, WC1E 6JJ, UK
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18
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Killick R, Scales G, Leroy K, Causevic M, Hooper C, Irvine EE, Choudhury AI, Drinkwater L, Kerr F, Al-Qassab H, Stephenson J, Yilmaz Z, Giese KP, Brion JP, Withers DJ, Lovestone S. Deletion of Irs2 reduces amyloid deposition and rescues behavioural deficits in APP transgenic mice. Biochem Biophys Res Commun 2009; 386:257-62. [PMID: 19523444 PMCID: PMC2726921 DOI: 10.1016/j.bbrc.2009.06.032] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 06/07/2009] [Indexed: 11/20/2022]
Abstract
As impaired insulin signalling (IIS) is a risk factor for Alzheimer’s disease we crossed mice (Tg2576) over-expressing human amyloid precursor protein (APP), with insulin receptor substrate 2 null (Irs2−/−) mice which develop insulin resistance. The resulting Tg2576/Irs2−/− animals had increased tau phosphorylation but a paradoxical amelioration of Aβ pathology. An increase of the Aβ binding protein transthyretin suggests that increased clearance of Aβ underlies the reduction in plaques. Increased tau phosphorylation correlated with reduced tau-phosphatase PP2A, despite an inhibition of the tau-kinase glycogen synthase kinase-3. Our findings demonstrate that disruption of IIS in Tg2576 mice has divergent effects on pathological processes—a reduction in aggregated Aβ but an increase in tau phosphorylation. However, as these effects are accompanied by improvement in behavioural deficits, our findings suggest a novel protective effect of disrupting IRS2 signalling in AD which may be a useful therapeutic strategy for this condition.
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Affiliation(s)
- Richard Killick
- King's College London, MRC Centre for Neurodegenerative Research, Institute of Psychiatry, De Crespigny Park, London, SE5 8AF, UK
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19
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Hisadome K, Smith MA, Choudhury AI, Claret M, Withers DJ, Ashford MLJ. 5-HT inhibition of rat insulin 2 promoter Cre recombinase transgene and proopiomelanocortin neuron excitability in the mouse arcuate nucleus. Neuroscience 2008; 159:83-93. [PMID: 19135134 PMCID: PMC2661429 DOI: 10.1016/j.neuroscience.2008.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 11/28/2008] [Accepted: 12/02/2008] [Indexed: 11/28/2022]
Abstract
A number of anti-obesity agents have been developed that enhance hypothalamic 5-HT transmission. Various studies have demonstrated that arcuate neurons, which express proopiomelanocortin peptides (POMC neurons), and neuropeptide Y with agouti-related protein (NPY/AgRP) neurons, are components of the hypothalamic circuits responsible for energy homeostasis. An additional arcuate neuron population, rat insulin 2 promoter Cre recombinase transgene (RIPCre) neurons, has recently been implicated in hypothalamic melanocortin circuits involved in energy balance. It is currently unclear how 5-HT modifies neuron excitability in these local arcuate neuronal circuits. We show that 5-HT alters the excitability of the majority of mouse arcuate RIPCre neurons, by either hyperpolarization and inhibition or depolarization and excitation. RIPCre neurons sensitive to 5-HT, predominantly exhibit hyperpolarization and pharmacological studies indicate that inhibition of neuronal firing is likely to be through 5-HT1F receptors increasing current through a voltage-dependent potassium conductance. Indeed, 5-HT1F receptor immunoreactivity co-localizes with RIPCre green fluorescent protein expression. A minority population of POMC neurons also respond to 5-HT by hyperpolarization, and this appears to be mediated by the same receptor-channel mechanism. As neither POMC nor RIPCre neuronal populations display a common electrical response to 5-HT, this may indicate that sub-divisions of POMC and RIPCre neurons exist, perhaps serving different outputs.
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Affiliation(s)
- K Hisadome
- Biomedical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, Scotland, UK
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20
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Selman C, Lingard S, Choudhury AI, Batterham RL, Claret M, Clements M, Ramadani F, Okkenhaug K, Schuster E, Blanc E, Piper MD, Al‐Qassab H, Speakman JR, Carmignac D, Robinson ICA, Thornton JM, Gems D, Partridge L, Withers DJ. Evidence for lifespan extension and delayed age–related biomarkers in insulin receptor substrate 1 null mice. FASEB J 2007; 22:807-18. [DOI: 10.1096/fj.07-9261com] [Citation(s) in RCA: 419] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Colin Selman
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Steven Lingard
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Agharul I. Choudhury
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Rachel L. Batterham
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Marc Claret
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Melanie Clements
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Faruk Ramadani
- Laboratory of Lymphocyte Signalling and DevelopmentThe Babraham InstituteBabraham Research CampusCambridgeUK
| | - Klaus Okkenhaug
- Laboratory of Lymphocyte Signalling and DevelopmentThe Babraham InstituteBabraham Research CampusCambridgeUK
| | - Eugene Schuster
- European Bioinformatics InstituteWellcome Trust Genome CampusHinxtonCambridgeUK
| | - Eric Blanc
- European Bioinformatics InstituteWellcome Trust Genome CampusHinxtonCambridgeUK
| | - Matthew D. Piper
- Centre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Hind Al‐Qassab
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - John R. Speakman
- Aberdeen Centre for Energy Regulation and Obesity (ACERO)School of Biological SciencesUniversity of AberdeenAberdeenUK
| | - Danielle Carmignac
- Division of Molecular NeuroendocrinologyMedical Research Council National Institute of Medical ResearchLondonUK
| | - Iain C. A. Robinson
- Division of Molecular NeuroendocrinologyMedical Research Council National Institute of Medical ResearchLondonUK
| | - Janet M. Thornton
- European Bioinformatics InstituteWellcome Trust Genome CampusHinxtonCambridgeUK
| | - David Gems
- Centre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Linda Partridge
- Centre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
| | - Dominic J. Withers
- Centre for Diabetes and EndocrinologyDepartment of MedicineRayne InstituteCentre for Research on AgeingDepartment of BiologyUniversity College LondonLondonUK
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21
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Claret M, Smith MA, Batterham RL, Selman C, Choudhury AI, Fryer LG, Clements M, Al-Qassab H, Heffron H, Xu AW, Speakman JR, Barsh GS, Viollet B, Vaulont S, Ashford ML, Carling D, Withers DJ. AMPK is essential for energy homeostasis regulation and glucose sensing by POMC and AgRP neurons. J Clin Invest 2007; 117:2325-36. [PMID: 17671657 PMCID: PMC1934578 DOI: 10.1172/jci31516] [Citation(s) in RCA: 385] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 04/24/2007] [Indexed: 01/13/2023] Open
Abstract
Hypothalamic AMP-activated protein kinase (AMPK) has been suggested to act as a key sensing mechanism, responding to hormones and nutrients in the regulation of energy homeostasis. However, the precise neuronal populations and cellular mechanisms involved are unclear. The effects of long-term manipulation of hypothalamic AMPK on energy balance are also unknown. To directly address such issues, we generated POMC alpha 2KO and AgRP alpha 2KO mice lacking AMPK alpha2 in proopiomelanocortin- (POMC-) and agouti-related protein-expressing (AgRP-expressing) neurons, key regulators of energy homeostasis. POMC alpha 2KO mice developed obesity due to reduced energy expenditure and dysregulated food intake but remained sensitive to leptin. In contrast, AgRP alpha 2KO mice developed an age-dependent lean phenotype with increased sensitivity to a melanocortin agonist. Electrophysiological studies in AMPK alpha2-deficient POMC or AgRP neurons revealed normal leptin or insulin action but absent responses to alterations in extracellular glucose levels, showing that glucose-sensing signaling mechanisms in these neurons are distinct from those pathways utilized by leptin or insulin. Taken together with the divergent phenotypes of POMC alpha 2KO and AgRP alpha 2KO mice, our findings suggest that while AMPK plays a key role in hypothalamic function, it does not act as a general sensor and integrator of energy homeostasis in the mediobasal hypothalamus.
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Affiliation(s)
- Marc Claret
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Mark A. Smith
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Rachel L. Batterham
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Colin Selman
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Agharul I. Choudhury
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Lee G.D. Fryer
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Melanie Clements
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Hind Al-Qassab
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Helen Heffron
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Allison W. Xu
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - John R. Speakman
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Gregory S. Barsh
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Benoit Viollet
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Sophie Vaulont
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Michael L.J. Ashford
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - David Carling
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
| | - Dominic J. Withers
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom.
Neurosciences Institute, Pathology and Neuroscience Division, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom.
Department of Genetics and Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.
Aberdeen Centre for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, United Kingdom.
INSERM U567, CNRS, UMR 8104, Institut Cochin, Université René Descartes, Paris, France
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22
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Cantley J, Choudhury AI, Asare-Anane H, Selman C, Lingard S, Heffron H, Herrera P, Persaud SJ, Withers DJ. Pancreatic deletion of insulin receptor substrate 2 reduces beta and alpha cell mass and impairs glucose homeostasis in mice. Diabetologia 2007; 50:1248-56. [PMID: 17393136 DOI: 10.1007/s00125-007-0637-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2006] [Accepted: 01/25/2007] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Insulin signalling pathways regulate pancreatic beta cell function. Conditional gene targeting using the Cre/loxP system has demonstrated that mice lacking insulin receptor substrate 2 (IRS2) in the beta cell have reduced beta cell mass. However, these studies have been complicated by hypothalamic deletion when the RIPCre (B6.Cg-tg(Ins2-cre)25Mgn/J) transgenic mouse (expressing Cre recombinase under the control of the rat insulin II promoter) is used to delete floxed alleles in insulin-expressing cells. These features have led to marked insulin resistance making the beta cell-autonomous role of IRS2 difficult to determine. To establish the effect of deleting Irs2 only in the pancreas, we generated PIrs2KO mice in which Cre recombinase expression was driven by the promoter of the pancreatic and duodenal homeobox factor 1 (Pdx1, also known as Ipf1) gene. MATERIALS AND METHODS In vivo glucose homeostasis was examined in PIrs2KO mice using glucose tolerance and glucose-stimulated insulin secretion tests. Endocrine cell mass was determined by morphometric analysis. Islet function was examined in static cultures and by performing calcium imaging in Fluo3am-loaded beta cells. Islet gene expression was determined by RT-PCR. RESULTS The PIrs2KO mice displayed glucose intolerance and impaired glucose-stimulated insulin secretion in vivo. Pancreatic insulin and glucagon content and beta and alpha cell mass were reduced. Glucose-stimulated insulin secretion and calcium mobilisation were attenuated in PIrs2KO islets. Expression of the Glut2 gene (also known as Slc2a2) was also reduced in PIrs2KO mice. CONCLUSIONS/INTERPRETATION These studies suggest that IRS2-dependent signalling in pancreatic islets is required not only for the maintenance of normal beta and alpha cell mass but is also involved in the regulation of insulin secretion.
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Affiliation(s)
- J Cantley
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, University Street, London, UK
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23
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Neganova I, Al-Qassab H, Heffron H, Selman C, Choudhury AI, Lingard SJ, Diakonov I, Patterson M, Ghatei M, Bloom SR, Franks S, Huhtaniemi I, Hardy K, Withers DJ. Role of central nervous system and ovarian insulin receptor substrate 2 signaling in female reproductive function in the mouse. Biol Reprod 2007; 76:1045-53. [PMID: 17329594 DOI: 10.1095/biolreprod.106.059360] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Insulin receptor signaling regulates female reproductive function acting in the central nervous system and ovary. Female mice that globally lack insulin receptor substrate (IRS) 2, which is a key mediator of insulin receptor action, are infertile with defects in hypothalamic and ovarian functions. To unravel the tissue-specific roles of IRS2, we examined reproductive function in female mice that lack Irs2 only in the neurons. Surprisingly, these animals had minimal defects in pituitary and ovarian hormone levels, ovarian anatomy and function, and breeding performance, which indicates that the central nervous system IRS2 is not an obligatory signaling component for the regulation of reproductive function. Therefore, we undertook a detailed analysis of ovarian function in a novel Irs2 global null mouse line. Comparative morphometric analysis showed reduced follicle size, increased numbers of atretic follicles, as well as impaired oocyte growth and antral cavity development in Irs2 null ovaries. Granulosa cell proliferation was also defective in the Irs2 null ovaries. Furthermore, the insulin- and eCG-stimulated phosphoinositide-3-OH kinase signaling events, which included phosphorylation of Akt/protein kinase B and glycogen synthase kinase 3-beta, were impaired, whereas mitogen-activated protein kinase signaling was preserved in Irs2 null ovaries. These abnormalities were associated with reduced expression of cyclin D2 and increased CDKN1B levels, which indicates dysregulation of key components of the cell cycle apparatus implicated in ovarian function. Our data suggest that ovarian rather than central nervous system IRS2 signaling is important in the regulation of female reproductive function.
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Affiliation(s)
- Irina Neganova
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London WC1E 6JJ, United Kingdom
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24
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Simmgen M, Knauf C, Lopez M, Choudhury AI, Charalambous M, Cantley J, Bedford DC, Claret M, Iglesias MA, Heffron H, Cani PD, Vidal-Puig A, Burcelin R, Withers DJ. Liver-specific deletion of insulin receptor substrate 2 does not impair hepatic glucose and lipid metabolism in mice. Diabetologia 2006; 49:552-61. [PMID: 16404553 DOI: 10.1007/s00125-005-0084-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 09/25/2005] [Indexed: 10/25/2022]
Abstract
AIMS/HYPOTHESIS Hepatic insulin resistance is thought to be a critical component in the pathogenesis of type 2 diabetes but the role of intrinsic insulin signalling pathways in the regulation of hepatic metabolism remains controversial. Global gene targeting in mice and in vitro studies have suggested that IRS2 mediates the physiological effects of insulin in the liver. Reduced hepatic production of IRS2 is found in many cases of insulin resistance. To investigate the role of IRS2 in regulating liver function in vivo, we generated mice that specifically lack Irs2 in the liver (LivIrs2KO). MATERIALS AND METHODS Hepatic insulin signalling events were examined in LivIrs2KO mice by western blotting. Glucose homeostasis and insulin sensitivity were assessed by glucose tolerance tests and hyperinsulinaemic-euglycaemic clamp studies. The effects of high-fat feeding upon glucose homeostasis were also determined. Liver function tests were performed and expression of key metabolic genes in the liver was determined by RT-PCR. RESULTS Proximal insulin signalling events and forkhead box O1 and A2 function were normal in the liver of LivIrs2KO mice, which displayed minimal abnormalities in glucose and lipid homeostasis, hepatic gene expression and liver function. In addition, hepatic lipid homeostasis and the metabolic response to a high-fat diet did not differ between LivIrs2KO and control mice. CONCLUSIONS/INTERPRETATION Our findings suggest that liver IRS2 signalling, surprisingly, is not required for the long-term maintenance of glucose and lipid homeostasis, and that extra-hepatic IRS2-dependent mechanisms are involved in the regulation of these processes.
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Affiliation(s)
- M Simmgen
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, University Street, London, UK
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25
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Choudhury AI, Heffron H, Smith MA, Al-Qassab H, Xu AW, Selman C, Simmgen M, Clements M, Claret M, Maccoll G, Bedford DC, Hisadome K, Diakonov I, Moosajee V, Bell JD, Speakman JR, Batterham RL, Barsh GS, Ashford MLJ, Withers DJ. The role of insulin receptor substrate 2 in hypothalamic and beta cell function. J Clin Invest 2005; 115:940-50. [PMID: 15841180 PMCID: PMC1069106 DOI: 10.1172/jci24445] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Accepted: 02/22/2005] [Indexed: 11/17/2022] Open
Abstract
Insulin receptor substrate 2 (Irs2) plays complex roles in energy homeostasis. We generated mice lacking Irs2 in beta cells and a population of hypothalamic neurons (RIPCreIrs2KO), in all neurons (NesCreIrs2KO), and in proopiomelanocortin neurons (POMCCreIrs2KO) to determine the role of Irs2 in the CNS and beta cell. RIPCreIrs2KO mice displayed impaired glucose tolerance and reduced beta cell mass. Overt diabetes did not ensue, because beta cells escaping Cre-mediated recombination progressively populated islets. RIPCreIrs2KO and NesCreIrs2KO mice displayed hyperphagia, obesity, and increased body length, which suggests altered melanocortin action. POMCCreIrs2KO mice did not display this phenotype. RIPCreIrs2KO and NesCreIrs2KO mice retained leptin sensitivity, which suggests that CNS Irs2 pathways are not required for leptin action. NesCreIrs2KO and POMCCreIrs2KO mice did not display reduced beta cell mass, but NesCreIrs2KO mice displayed mild abnormalities of glucose homeostasis. RIPCre neurons did not express POMC or neuropeptide Y. Insulin and a melanocortin agonist depolarized RIPCre neurons, whereas leptin was ineffective. Insulin hyperpolarized and leptin depolarized POMC neurons. Our findings demonstrate a critical role for IRS2 in beta cell and hypothalamic function and provide insights into the role of RIPCre neurons, a distinct hypothalamic neuronal population, in growth and energy homeostasis.
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Affiliation(s)
- Agharul I Choudhury
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, London, United Kingdom
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26
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Jeffery B, Choudhury AI, Horley N, Bruce M, Tomlinson SR, Roberts RA, Gray TJB, Barrett DA, Shaw PN, Kendall D, Bell DR. Peroxisome proliferator activated receptor alpha regulates a male-specific cytochrome P450 in mouse liver. Arch Biochem Biophys 2004; 429:231-6. [PMID: 15313227 DOI: 10.1016/j.abb.2004.06.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 06/15/2004] [Indexed: 11/29/2022]
Abstract
We set out to find if the strain-specific, male-specific hepatic expression of Cyp4a protein in mouse was due to expression of Cyp4a12 and to understand the genetic basis for reported differences in expression. 12-Lauric acid hydroxylase (LAH) activity was found to show higher levels in male ddY, but not C57Bl/6, mouse liver microsomes. The expression of Cyp4a12 mRNA was studied using RNAase protection assays in male and female liver and kidney of nine mouse strains. Cyp4a12 was found to be highly expressed in male liver and kidney, but at much lower levels in female liver and kidney, in all strains studied. Western blotting with an antibody specific for Cyp4a12 confirmed that Cyp4a12 was expressed in a male specific fashion in C57Bl/6 mouse liver. RNAase protection analysis for Cyp4a10 and 14 in ddY mice revealed that neither of these genes showed male-specific expression. To further investigate genetic factors that control male-specific Cyp4a12 expression, PPARalpha+/+ and -/- mice were studied, showing that total P450 and 12-LAH activity was male-specific in +/+, but not -/- mice. RNAase protection assays were used to confirm that Cyp4a12 was lower in -/- mice. However, the male-specific Slp and MUP-1 genes retained hepatic male-specific levels of expression in +/+ and -/- mice, showing that the decrease in Cyp4a12 was not a general effect on male-specific expression. Thus, PPARalpha has a specific effect on constitutive expression of Cyp4a12.
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Affiliation(s)
- Brett Jeffery
- School of Biology, University Park, University of Nottingham, Nottingham NG7 2RD, UK
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27
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Choudhury AI, Sims HM, Horley NJ, Roberts RA, Tomlinson SR, Salter AM, Bruce M, Shaw PN, Kendall D, Barrett DA, Bell DR. Molecular analysis of peroxisome proliferation in the hamster. Toxicol Appl Pharmacol 2004; 197:9-18. [PMID: 15126070 DOI: 10.1016/j.taap.2004.01.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2003] [Accepted: 01/14/2004] [Indexed: 12/01/2022]
Abstract
Three novel P450 members of the cytochrome P450 4A family were cloned as partial cDNAs from hamster liver, characterised as novel members of the CYP4A subfamily, and designated CYP4A17, 18, and 19. Hamsters were treated with the peroxisome proliferator-activated receptor alpha (PPARalpha) agonists, methylclofenapate (MCP) or Wy-14,643, and shown to develop hepatomegaly and induction of CYP4A17 RNA, and concomitant induction of lauric acid 12- hydroxylase. This treatment also resulted in hypolipidaemia, which was most pronounced in the VLDL fraction, with up to 50% reduction in VLDL-triglycerides; by contrast, blood cholesterol concentration was unaffected by this treatment. These data show that hamster is highly responsive to induction of CYP4A by peroxisome proliferators. To characterise the molecular basis of peroxisome proliferation, the hamster PPARalpha was cloned and shown to encode a 468-amino-acid protein, which is highly similar to rat and mouse PPARalpha proteins. The level of expression of hamster PPARalpha in liver is intermediate between mouse and guinea pig. These results fail to support the hypothesis that the level of PPARalpha in liver is directly responsible for species differences in peroxisome proliferation.
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28
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Abstract
Peroxisome proliferators are a class of structurally diverse chemicals, which induce liver carcinogenesis in rodents through interaction and activation of the Peroxisome Proliferator-Activated Receptor alpha (PPARalpha). PPARalpha agonists elicit a powerful pleiotropic response, which include hypolipidaemia. We have examined the response of species that are classically unresponsive to peroxisome proliferators. Whereas hamster responds to PPARalpha agonists by hepatomegaly and induction of marker genes, the guinea pig does not undergo hepatomegaly or induction of marker genes, such as CYP4A13. Both the hamster and the guinea pig have PPARalpha, and the guinea pig receptor has been characterised to be fully functional, as demonstrated in reporter gene expression assays. However, the guinea pig PPARalpha is expressed at low levels in liver, and the currently favoured hypothesis to explain species differences in hepatic peroxisome proliferation invokes the low level of PPARalpha as the principal determinant of species responsiveness. However, the demonstration that guinea pigs and humans undergo hypolipidaemia induced by PPARalpha-agonists calls into question the mode of action of PPARalpha agonists in "non-responsive" species.
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Affiliation(s)
- A I Choudhury
- School of Biological Sciences, University of Nottingham, University Park, NG7 2RD, Nottingham, UK
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29
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Bell AR, Savory R, Horley NJ, Choudhury AI, Dickins M, Gray TJ, Salter AM, Bell DR. Molecular basis of non-responsiveness to peroxisome proliferators: the guinea-pig PPARalpha is functional and mediates peroxisome proliferator-induced hypolipidaemia. Biochem J 1998; 332 ( Pt 3):689-93. [PMID: 9620871 PMCID: PMC1219529 DOI: 10.1042/bj3320689] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The guinea pig does not undergo peroxisome proliferation in response to peroxisome proliferators, in contrast with other rodents. To understand the molecular basis of this phenotype, the peroxisome proliferator activated receptor alpha (PPARalpha) from guinea-pig liver was cloned; it encodes a protein of 467 amino acid residues that is similar to rodent and human PPARalpha. The guinea-pig PPARalpha showed a high substitution rate: maximum likelihood analysis was consistent with rodent monophyly, but could not exclude rodent polyphyly (P approximately 0.06). The guinea-pig PPARalpha cDNA was expressed in 293 cells and mediated the induction of the luciferase reporter gene by the peroxisome proliferator, Wy-14,643, dependent on the presence of a peroxisome proliferator response element. Moreover the PPARalpha RNA and protein were expressed in guinea-pig liver, although at lower levels than in a species which is responsive to peroxisome proliferators, the mouse. To determine whether the guinea-pig PPARalpha mediated any physiological effects, guinea pigs were exposed to two selective PPARalpha agonists, Wy-14, 643 and methylclofenapate; both compounds induced hypolipidaemia. Thus the guinea pig is a useful model for human responses to peroxisome proliferators.
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Affiliation(s)
- A R Bell
- School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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