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Burke LK, Ogunnowo-Bada E, Georgescu T, Cristiano C, de Morentin PBM, Valencia Torres L, D'Agostino G, Riches C, Heeley N, Ruan Y, Rubinstein M, Low MJ, Myers MG, Rochford JJ, Evans ML, Heisler LK. Lorcaserin improves glycemic control via a melanocortin neurocircuit. Mol Metab 2017; 6:1092-1102. [PMID: 29031711 PMCID: PMC5641625 DOI: 10.1016/j.molmet.2017.07.004] [Citation(s) in RCA: 30] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/05/2017] [Accepted: 07/10/2017] [Indexed: 02/07/2023] Open
Abstract
Objective The increasing prevalence of type 2 diabetes (T2D) and associated morbidity and mortality emphasizes the need for a more complete understanding of the mechanisms mediating glucose homeostasis to accelerate the identification of new medications. Recent reports indicate that the obesity medication lorcaserin, a 5-hydroxytryptamine (5-HT, serotonin) 2C receptor (5-HT2CR) agonist, improves glycemic control in association with weight loss in obese patients with T2D. Here we evaluate whether lorcaserin has an effect on glycemia without body weight loss and how this effect is achieved. Methods Murine models of common and genetic T2D were utilized to probe the direct effect of lorcaserin on glycemic control. Results Lorcaserin dose-dependently improves glycemic control in mouse models of T2D in the absence of reductions in food intake or body weight. Examining the mechanism of this effect, we reveal a necessary and sufficient neurochemical mediator of lorcaserin's glucoregulatory effects, brain pro-opiomelanocortin (POMC) peptides. To clarify further lorcaserin's therapeutic brain circuit, we examined the receptor target of POMC peptides. We demonstrate that lorcaserin requires functional melanocortin4 receptors on cholinergic preganglionic neurons (MC4RChAT) to exert its effects on glucose homeostasis. In contrast, MC4RChAT signaling did not impact lorcaserin's effects on feeding, indicating a divergence in the neurocircuitry underpinning lorcaserin's therapeutic glycemic and anorectic effects. Hyperinsulinemic-euglycemic clamp studies reveal that lorcaserin reduces hepatic glucose production, increases glucose disposal and improves insulin sensitivity. Conclusions These data suggest that lorcaserin's action within the brain represents a mechanistically novel treatment for T2D: findings of significance to a prevalent global disease. Obesity medication lorcaserin directly improves glycemic control without altering energy balance or body weight. Unlike current frontline type 2 diabetes medications, lorcaserin acts within the brain to improve glycemic control. Brain Pro-opiomelanocortin (POMC) peptides are a neurochemical mediator of lorcaserin's glucoregulatory effects. Lorcaserin increases insulin sensitivity, reduces hepatic glucose production and increases glucose disposal.
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Affiliation(s)
- Luke K Burke
- Department of Pharmacology, University of Cambridge, Cambridge, UK; Department of Medicine and Wellcome Trust/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Emmanuel Ogunnowo-Bada
- Department of Medicine and Wellcome Trust/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | | | | | | | - Lourdes Valencia Torres
- Department of Pharmacology, University of Cambridge, Cambridge, UK; The Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Giuseppe D'Agostino
- Department of Pharmacology, University of Cambridge, Cambridge, UK; The Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Christine Riches
- Department of Medicine and Wellcome Trust/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Nicholas Heeley
- Department of Medicine and Wellcome Trust/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Yue Ruan
- Department of Medicine and Wellcome Trust/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Martin G Myers
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Mark L Evans
- Department of Medicine and Wellcome Trust/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK.
| | - Lora K Heisler
- Department of Pharmacology, University of Cambridge, Cambridge, UK; The Rowett Institute, University of Aberdeen, Aberdeen, UK.
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Pauliina Markkula S, Lyons D, Yueh CY, Riches C, Hurst P, Fielding B, Heisler LK, Evans ML. Intracerebroventricular Catalase Reduces Hepatic Insulin Sensitivity and Increases Responses to Hypoglycemia in Rats. Endocrinology 2016; 157:4669-4676. [PMID: 27740870 PMCID: PMC5133351 DOI: 10.1210/en.2015-2054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Specialized metabolic sensors in the hypothalamus regulate blood glucose levels by influencing hepatic glucose output and hypoglycemic counterregulatory responses. Hypothalamic reactive oxygen species (ROS) may act as a metabolic signal-mediating responses to changes in glucose, other substrates and hormones. The role of ROS in the brain's control of glucose homeostasis remains unclear. We hypothesized that hydrogen peroxide (H2O2), a relatively stable form of ROS, acts as a sensor of neuronal glucose consumption and availability and that lowering brain H2O2 with the enzyme catalase would lead to systemic responses increasing blood glucose. During hyperinsulinemic euglycemic clamps in rats, intracerebroventricular catalase infusion resulted in increased hepatic glucose output, which was associated with reduced neuronal activity in the arcuate nucleus of the hypothalamus. Electrophysiological recordings revealed a subset of arcuate nucleus neurons expressing proopiomelanocortin that were inhibited by catalase and excited by H2O2. During hypoglycemic clamps, intracerebroventricular catalase increased glucagon and epinephrine responses to hypoglycemia, consistent with perceived lower glucose levels. Our data suggest that H2O2 represents an important metabolic cue, which, through tuning the electrical activity of key neuronal populations such as proopiomelanocortin neurons, may have a role in the brain's influence of glucose homeostasis and energy balance.
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Affiliation(s)
- S Pauliina Markkula
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
| | - David Lyons
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
| | - Chen-Yu Yueh
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
| | - Christine Riches
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
| | - Paul Hurst
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
| | - Barbara Fielding
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
| | - Lora K Heisler
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
| | - Mark L Evans
- Wellcome Trust/Medical Research Council Institute of Metabolic Science and Department of Medicine (S.P.M., C.-Y.Y., C.R., P.H., M.L.E.), University of Cambridge, Cambridge CB20QQ, United Kingdom; Rowett Institute of Nutrition and Health (D.L., L.K.H.), University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Department of Family Medicine (C.-Y.Y.), Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology (C.-Y.Y.), Taoyuan City 33303, Taiwan; Oxford Centre for Diabetes, Endocrinology and Metabolism (B.F.), University of Oxford, Oxford OX37JT, United Kingdom; and Department of Nutritional Sciences (B.F.), University of Surrey, Guildford GU27XH, United Kingdom
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