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Singha AK, Yamaguchi J, Gonzalez NS, Ahmed N, Toney GM, Fujikawa T. Glucose-Lowering by Leptin in the Absence of Insulin Does Not Fully Rely on the Central Melanocortin System in Male Mice. Endocrinology 2019; 160:651-663. [PMID: 30698681 PMCID: PMC6388659 DOI: 10.1210/en.2018-00907] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/24/2019] [Indexed: 12/11/2022]
Abstract
Central leptin administration can ameliorate hyperglycemia in insulin-deficient rodent models independently of insulin; however, the underlying neuronal mechanism are unclear. Here, we investigate the contribution of key elements within the central melanocortin system by examining whether central leptin injection can ameliorate hyperglycemia in total insulin-deficient mice that either lacked melanocortin 4 receptors (MC4Rs) in the whole body [knockout (KO); MC4R KO] or selectively, in single-minded homolog 1 (SIM1)-expressing neurons (SIM1ΔMC4R). We further investigated the contribution of leptin receptors (LEPRs) in agouti-related protein (AgRP)-expressing neurons (AgRP∆LEPR). Leptin injections into the cerebral ventricle attenuated mortality and elevated blood glucose in total insulin-deficient MC4R KO mice. Total insulin-deficient SIM1ΔMC4R mice exhibited the same magnitude reduction of blood glucose in response to leptin injections as MC4R KO mice, suggesting SIM1 neurons are key to MC4R-mediated, insulin-independent, glucose-lowering effects of leptin. Central leptin injection also partially rescued glucose levels in total insulin-deficient AgRP∆LEPR mice. In brain slice studies, basal discharge of AgRP neurons from mice with total insulin deficiency was increased and leptin partially reduced their firing rate without membrane potential hyperpolarization. Collectively, our findings indicate that, contrary to glucose-lowering effects of leptin in the presence of insulin or partial insulin deficiency, MC4Rs in SIM1 neurons and LEPRs in AgRP neurons are not solely responsible for glucose-lowering effects of leptin in total insulin deficiency. This indicates that the central melanocortin system operates with other neuronal systems to fully mediate glucose-lowering effects of leptin in an insulin-independent manner.
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Affiliation(s)
- Ashish K Singha
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
| | - Junya Yamaguchi
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
| | - Nancy S Gonzalez
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
| | - Newaz Ahmed
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Glenn M Toney
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
- Center for Biomedical Neuroscience, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
| | - Teppei Fujikawa
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
- Center for Biomedical Neuroscience, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
- Mouse Genome Engineering and Transgenic Facility, Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas
- Correspondence: Teppei Fujikawa, PhD, University of Texas Health San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229. E-mail:
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Pereira S, O'Dwyer SM, Webber TD, Baker RK, So V, Ellis CE, Yoon JS, Mojibian M, Glavas MM, Karunakaran S, Clee SM, Covey SD, Kieffer TJ. Metabolic effects of leptin receptor knockdown or reconstitution in adipose tissues. Sci Rep 2019; 9:3307. [PMID: 30824713 PMCID: PMC6397253 DOI: 10.1038/s41598-019-39498-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 12/31/2018] [Indexed: 01/26/2023] Open
Abstract
The relative contribution of peripheral and central leptin signalling to the regulation of metabolism and the mechanisms through which leptin affects glucose homeostasis have not been fully elucidated. We generated complementary lines of mice with either leptin receptor (Lepr) knockdown or reconstitution in adipose tissues using Cre-lox methodology. Lepr knockdown mice were modestly lighter and had lower plasma insulin concentrations following an oral glucose challenge compared to controls, despite similar insulin sensitivity. We rendered male mice diabetic using streptozotocin (STZ) and found that upon prolonged leptin therapy, Lepr knockdown mice had an accelerated decrease in blood glucose compared to controls that was associated with higher plasma concentrations of leptin and leptin receptor. Mice with transcriptional blockade of Lepr (LeprloxTB/loxTB) were obese and hyperglycemic and reconstitution of Lepr in adipose tissues of LeprloxTB/loxTB mice resulted in males reaching a higher maximal body weight. Although mice with adipose tissue Lepr reconstitution had lower blood glucose levels at several ages, their plasma insulin concentrations during an oral glucose test were elevated. Thus, attenuation or restoration of Lepr in adipocytes alters the plasma insulin profile following glucose ingestion, modifies the glucose-lowering effect of prolonged leptin therapy in insulin-deficient diabetes, and may modulate weight gain.
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Affiliation(s)
- Sandra Pereira
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Shannon M O'Dwyer
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Travis D Webber
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Robert K Baker
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Victor So
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Cara E Ellis
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Ji Soo Yoon
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Majid Mojibian
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Maria M Glavas
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Subashini Karunakaran
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Susanne M Clee
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Scott D Covey
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada. .,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.
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53
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Clemmensen C, Finan B, Müller TD, DiMarchi RD, Tschöp MH, Hofmann SM. Emerging hormonal-based combination pharmacotherapies for the treatment of metabolic diseases. Nat Rev Endocrinol 2019; 15:90-104. [PMID: 30446744 DOI: 10.1038/s41574-018-0118-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Obesity and its comorbidities, such as type 2 diabetes mellitus and cardiovascular disease, constitute growing challenges for public health and economies globally. The available treatment options for these metabolic disorders cannot reverse the disease in most individuals and have not substantially reduced disease prevalence, which underscores the unmet need for more efficacious interventions. Neurobiological resilience to energy homeostatic perturbations, combined with the heterogeneous pathophysiology of human metabolic disorders, has limited the sustainability and efficacy of current pharmacological options. Emerging insights into the molecular origins of eating behaviour, energy expenditure, dyslipidaemia and insulin resistance suggest that coordinated targeting of multiple signalling pathways is probably necessary for sizeable improvements to reverse the progression of these diseases. Accordingly, a broad set of combinatorial approaches targeting feeding circuits, energy expenditure and glucose metabolism in concert are currently being explored and developed. Notably, several classes of peptide-based multi-agonists and peptide-small molecule conjugates with superior preclinical efficacy have emerged and are currently undergoing clinical evaluation. Here, we summarize advances over the past decade in combination pharmacotherapy for the management of obesity and type 2 diabetes mellitus, exclusively focusing on large-molecule formats (notably enteroendocrine peptides and proteins) and discuss the associated therapeutic opportunities and challenges.
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Affiliation(s)
- Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.
| | - Brian Finan
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN, USA
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | | | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität, Munich, Germany
| | - Susanna M Hofmann
- Institute for Diabetes and Regeneration, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.
- Medizinische Klinik und Poliklinik IV, Klinikum der Ludwig-Maximilians-Universität München, Munich, Germany.
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Perry RJ, Rabin-Court A, Song JD, Cardone RL, Wang Y, Kibbey RG, Shulman GI. Dehydration and insulinopenia are necessary and sufficient for euglycemic ketoacidosis in SGLT2 inhibitor-treated rats. Nat Commun 2019; 10:548. [PMID: 30710078 PMCID: PMC6358621 DOI: 10.1038/s41467-019-08466-w] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 01/07/2019] [Indexed: 12/15/2022] Open
Abstract
Sodium-glucose transport protein 2 (SGLT2) inhibitors are a class of anti-diabetic agents; however, concerns have been raised about their potential to induce euglycemic ketoacidosis and to increase both glucose production and glucagon secretion. The mechanisms behind these alterations are unknown. Here we show that the SGLT2 inhibitor (SGLT2i) dapagliflozin promotes ketoacidosis in both healthy and type 2 diabetic rats in the setting of insulinopenia through increased plasma catecholamine and corticosterone concentrations secondary to volume depletion. These derangements increase white adipose tissue (WAT) lipolysis and hepatic acetyl-CoA content, rates of hepatic glucose production, and hepatic ketogenesis. Treatment with a loop diuretic, furosemide, under insulinopenic conditions replicates the effect of dapagliflozin and causes ketoacidosis. Furthermore, the effects of SGLT2 inhibition to promote ketoacidosis are independent from hyperglucagonemia. Taken together these data in rats identify the combination of insulinopenia and dehydration as a potential target to prevent euglycemic ketoacidosis associated with SGLT2i. The use of sodium-glucose transport protein 2 (SGLT2) inhibitors for the treatment of diabetes has been associated with euglycemic ketoacidosis and increased glucose production and glucagon secretion. Here Perry et al. show that these effects rely on both insulinopenia and dehydration, and thus suggest ways to manage the side effects associated with the use of SGLT2 inhibitors.
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Affiliation(s)
- Rachel J Perry
- Departments of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA.,Departments of Cellular and Molecular Physiology, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA
| | - Aviva Rabin-Court
- Departments of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA
| | - Joongyu D Song
- Departments of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA
| | - Rebecca L Cardone
- Departments of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA
| | - Yongliang Wang
- Departments of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA
| | - Richard G Kibbey
- Departments of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA.,Departments of Cellular and Molecular Physiology, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA
| | - Gerald I Shulman
- Departments of Internal Medicine, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA. .,Departments of Cellular and Molecular Physiology, Yale University School of Medicine, P.O. Box 208020, TAC S269, New Haven, CT, 06519, USA.
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55
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Flier JS. Starvation in the Midst of Plenty: Reflections on the History and Biology of Insulin and Leptin. Endocr Rev 2019; 40:1-16. [PMID: 30357355 PMCID: PMC6270967 DOI: 10.1210/er.2018-00179] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/13/2018] [Indexed: 02/08/2023]
Abstract
Insulin and leptin are critical metabolic hormones that play essential but distinct roles in regulating the physiologic switch between the fed and starved states. The discoveries of insulin and leptin, in 1922 and 1994, respectively, arose out of radically different scientific environments. Despite the dearth of scientific tools available in 1922, insulin's discovery rapidly launched a life-saving therapy for what we now know to be type I diabetes, and continually enhanced insulin therapeutics are now effectively applied to both major forms of this increasingly prevalent disease. In contrast, although the discovery of leptin provided deep insights into the regulation of central nervous system energy balance circuits, as well as an effective therapy for an extremely rare form of obesity, its therapeutic impact beyond that has been surprisingly limited. Despite an enormous accumulated body of information, many important questions remain unanswered about the mechanisms of action and role in disease of both hormones. Additionally, although many decades apart, both discoveries reveal the complexities inherent to scientific collaboration and the assignment of credit, even when the efforts are spectacularly successful.
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Affiliation(s)
- Jeffrey S Flier
- Department of Medicine and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
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56
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Mi J, He W, Lv J, Zhuang K, Huang H, Quan S. Effect of berberine on the HPA-axis pathway and skeletal muscle GLUT4 in type 2 diabetes mellitus rats. Diabetes Metab Syndr Obes 2019; 12:1717-1725. [PMID: 31564939 PMCID: PMC6731988 DOI: 10.2147/dmso.s211188] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/10/2019] [Indexed: 12/19/2022] Open
Abstract
PURPOSE Activation of the hypothalamus-pituitary-adrenal (HPA) axis pathway is closely related to insulin resistance (IR), glucose, and lipid metabolism disorders in type 2 diabetes mellitus (T2DM). Berberine (BBR) has effect on regulating disorder of glucose and lipid metabolism in T2DM. In fact, activation of the HPA axis pathway is closely related to IR, glucose, and lipid metabolism disorders in T2DM. Here, we investigated whether the therapeutic effect of BBR on T2DM rats is acted through the HPA axis pathway. METHODS In this research, we investigated the effects of BBR on the HPA-axis pathway-related indicators and expression of skeletal muscle glucose transporter 4 (GLUT4) in the high-fat diet and streptozotocin-induced T2DM rats, and identify its possible mechanism of improving IR in T2DM. RESULTS BBR significantly reduced fasting blood glucose, total cholesterol, and low-density lipoprotein cholesterol in model rats. It also improved the abnormalities of the high-density lipoprotein cholesterol, the insulin resistance index, the insulin sensitivity index, glucagon, and insulin levels. BBR decreased levels of hypothalamic Orexin-A, the OX2R receptor, the corticotropin-releasing hormone, the pituitary and the plasma adrenocorticotropic hormone, as well as serum and urine corticosterone. At the same time, BBR increased mRNA and protein expressions of GLUT4 in skeletal muscles of model rats as well. CONCLUSION Those results suggested that BBR can exert inhibition on the HPA-axis and increased skeletal muscle expression of GLUT4 proteins, which may be one of the important mechanisms in BBR to improve IR and regulating glucose and lipid metabolism in T2DM rats.
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Affiliation(s)
- Jia Mi
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, People’s Republic of China
| | - Wenda He
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, People’s Republic of China
| | - Jiawei Lv
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, People’s Republic of China
| | - Kai Zhuang
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, People’s Republic of China
| | - Heqing Huang
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, People’s Republic of China
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, People’s Republic of China
- Correspondence: Heqing Huang; Shijian QuanDepartment of School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, No. 232 East Wai Huan Road, Guangzhou510006, People’s Republic of ChinaTel +86 1 392 211 9719Email ;
| | - Shijian Quan
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, People’s Republic of China
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57
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Palhinha L, Liechocki S, Hottz ED, Pereira JADS, de Almeida CJ, Moraes-Vieira PMM, Bozza PT, Maya-Monteiro CM. Leptin Induces Proadipogenic and Proinflammatory Signaling in Adipocytes. Front Endocrinol (Lausanne) 2019; 10:841. [PMID: 31920961 PMCID: PMC6923660 DOI: 10.3389/fendo.2019.00841] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Leptin is an adipokine with well-known effects on the central nervous system including the induction of energy expenditure and satiety. Leptin also has major relevance when activating immune cells and modulating inflammatory response. In obesity, increases in white adipose tissue accumulation and leptin levels are accompanied by hypothalamic resistance to leptin. Even though the adipose tissue is a leptin-rich environment, the local actions of leptin regarding adipogenesis were not thoroughly investigated until now. Here we evaluate the contributions of leptins direct signaling in preadipocytes and adipose tissue-derived stromal cells (ASCs) for adipogenesis. Methods: Adipocytes were differentiated from the murine lineage of preadipocytes 3T3-L1 or ASCs from subcutaneous and visceral (retroperitoneal) fat depots from C57Bl/6J mice. Differentiating cells were treated with leptin in addition to or in replacement of insulin. The advance of adipogenesis was assessed by the expression and secretion of adipogenesis- and lipogenesis-related proteins by Western blot and immunoenzimatic assays, and the accumulation of lipid droplets by fluorescence microscopy. Results: Leptin treatment in 3T3-L1 preadipocytes or ASCs increased the production of the adipogenesis- and lipogenesis-related proteins PLIN1, CAV-1, PPARγ, SREBP1C, and/or adiponectin at earlier stages of differentiation. In 3T3-L1 preadipocytes, we found that leptin induced lipid droplets' formation in an mTOR-dependent manner. Also, leptin induced a proinflammatory cytokine profile in 3T3-L1 and ASCs, modulating the production of TNF-α, IL-10, and IL-6. Since insulin is considered an essential factor for preadipocyte differentiation, we asked whether leptin would support adipogenesis in the absence of insulin. Importantly, leptin induced the formation of lipid droplets and the expression of adipogenesis-related proteins independently of insulin during the differentiation of 3T3-L1 cells and ASCs. Conclusions: Our results demonstrate that leptin induces intracellular signaling in preadipocytes and adipocytes promoting adipogenesis and modulating the secretion of inflammatory mediators. Also, leptin restores adipogenesis in the absence of insulin. These findings contribute to the understanding of the local signaling of leptin in precursor and mature adipose cells. The proadipogenic role of leptin unraveled here may be of especial relevance during obesity, when its central signaling is defective.
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Affiliation(s)
- Lohanna Palhinha
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil
| | - Sally Liechocki
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil
| | - Eugenio D. Hottz
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil
- Laboratory of Glycoconjugates Analysis, Department of Biochemistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Brazil
| | - Jéssica Aparecida da Silva Pereira
- Laboratory of Immunometabolism, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, Brazil
- Post-Graduate Program in Immunology, Institute of Biological Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Cecília J. de Almeida
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil
| | - Pedro Manoel M. Moraes-Vieira
- Laboratory of Immunometabolism, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, Brazil
- Post-Graduate Program in Immunology, Institute of Biological Sciences, University of Sao Paulo, São Paulo, Brazil
- Experimental Medicine Research Cluster, EMRC, University of Cammpinas, Campinas, Brazil
| | - Patrícia T. Bozza
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil
| | - Clarissa Menezes Maya-Monteiro
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil
- *Correspondence: Clarissa Menezes Maya-Monteiro ;
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Broderick TL, Sennott JM, Gutkowska J, Jankowski M. Anti-inflammatory and angiogenic effects of exercise training in cardiac muscle of diabetic mice. Diabetes Metab Syndr Obes 2019; 12:565-573. [PMID: 31118719 PMCID: PMC6499146 DOI: 10.2147/dmso.s197127] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/12/2019] [Indexed: 12/27/2022] Open
Abstract
Background: Improved glycemic control and cardiovascular function are major benefits of regular exercise training (ET) in type 2 diabetes. Recent work has demonstrated that ET improves cardiac and vascular functions independent of obesity, inflammation, and glucose control in the diabetic db/db mouse. In this study, we determined whether ET can overcome the effects of elevated inflammatory cytokines and hyperglycemia on markers of cardiac angiogenesis and inflammation in the diabetic mouse. Methods: Male diabetic db/db mice were assigned to a sedentary and exercise-trained group. Sedentary lean control littermates were used as controls. ET was performed at moderate intensity on a treadmill 5 days a week for a period of 8 weeks. After ET, blood was collected for assay of glucose, hemoglobin (HB and HB1AC), C-reactive protein (CRP), and IL-6. Markers of inflammation and insulin resistance (IL-6, IL-1β, and tumor necrosis factor-alpha [TNF-α]) and angiogenesis (endothelial nitric oxide synthase [eNOS], vascular endothelial growth factor-A [VEGF-A], and hypoxia-inducible factor-1α [HIF-1α]) were measured in hearts. Results: Diabetic db/db mice remained obese and hyperglycemic after ET. Percent total HB and HB1AC were significantly higher in ET db/db mice compared to sedentary db/db mice, indicating further deterioration of glucose control with ET. Plasma levels of CRP and IL-6 were higher in sedentary db/db mice compared to control mice and were unaffected by ET. However, in the presence of hyperglycemia and elevated plasma cytokines, protein expression of eNOS, mRNA expression of VEGF-A, and HIF-1α was increased in db/db hearts after ET. On the other hand, protein expression of TNF-α and mRNA expression IL-6 and IL-1β was significantly decreased by ET in hearts of db/db mice. Conclusion: Our results indicate that ET improves cardiac markers of angiogenesis, insulin resistance, and endothelial dysfunction in the db/db mouse. This was observed independently of obesity, hyperglycemia, and the systemic inflammatory state.
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Affiliation(s)
- Tom L Broderick
- Laboratory of Diabetes and Exercise Metabolism, Department of Physiology, College of Graduate Studies, Midwestern University, Glendale, AZ, USA
- Correspondence: Tom L BroderickLaboratory of Diabetes and Exercise Metabolism, Department of Physiology, College of Graduate Studies, Midwestern University, 19555 North 59 Avenue, Glendale, AZ85308, USATel +1 623 572 3664Fax +1 623 572 3673Email
| | - Jacqueline M Sennott
- Department of Cardiology, Medical Education H23, Saint-Joseph Mercy Health System, Pontiac, MI, USA
| | - Jolanta Gutkowska
- Cardiovascular Biochemistry Laboratory, CRCHUM (7-134), Department of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Marek Jankowski
- Cardiovascular Biochemistry Laboratory, CRCHUM (7-134), Department of Medicine, University of Montreal, Montreal, Quebec, Canada
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Li J, Shen X. Oxidative stress and adipokine levels were significantly correlated in diabetic patients with hyperglycemic crises. Diabetol Metab Syndr 2019; 11:13. [PMID: 30774721 PMCID: PMC6364461 DOI: 10.1186/s13098-019-0410-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/31/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND To investigate the relationship between blood adipokine level and oxidative stress in diabetic patients with hyperglycemic crises before and after treatment. METHODS We measured superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, total antioxidant capacity (TAC), and levels of 8-iso-prostaglandin F2α (8-iso-PGF2α), adiponectin, leptin, and resistin in 63 diabetic patients with hyperglycemic crises. RESULTS Prior to treatment, patients with hyperglycemic crises had significantly lower serum SOD activity, TAC, and adiponectin and leptin levels, and higher serum levels of MDA, 8-iso-PGF2α, and resistin compared with the healthy control individuals (all at P < 0.05). After treatment, SOD, TAC, adiponectin, and leptin levels increased significantly, while MDA, 8-iso-PGF2α, and resistin levels decreased significantly (all at P < 0.05) in the patients. CONCLUSIONS Diabetic patients with hyperglycemic crises have increased oxidative stress, which is associated with serum adipokine abnormalities; improved oxidative stress after treatment suggests that oxidative stress may serve as target and/or indicator for the treatment of hyperglycemic crises.
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Affiliation(s)
- Juan Li
- Department of Emergency, Zhongshan Hospital Xiamen University, Xiamen, 361004 Fujian China
| | - Xingping Shen
- Department of Endocrinology, Zhongshan Hospital Xiamen University, Xiamen, 361004 Fujian China
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60
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Ding HR, Wang JL, Ren HZ, Shi XL. Lipometabolism and Glycometabolism in Liver Diseases. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1287127. [PMID: 31205932 PMCID: PMC6530156 DOI: 10.1155/2018/1287127] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/03/2018] [Indexed: 12/12/2022]
Abstract
The liver is the main metabolic organ in the body especially in lipometabolism and glycometabolism. Carbohydrates and fats disorders can result in insulin resistance in the liver. Metabolic imbalance can even lead to life-threatening conditions. Therefore, it is essential to maintain the normal metabolic function of the liver. When the liver is in a pathological state, liver metabolism homeostasis is damaged, and metabolic disorders will further aggravate liver disease. Consequently, it is essential to determine the relationship between liver diseases and metabolic disorders. Here we review a lot of evidence that liver diseases are closely related to lipometabolism and glycometabolism. Although the disorder of the liver metabolism is caused by different liver diseases, the break of metabolic balance is determined by changes in the state of the liver. We discuss the relationship between liver disease and metabolic changes, outline the process of how metabolic changes are regulated by liver diseases, and describe the role which metabolic changes play in the process and prognosis of liver disease.
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Affiliation(s)
- Hao-ran Ding
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jing-lin Wang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Hao-zhen Ren
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xiao-lei Shi
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
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61
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Neumann UH, Kwon MM, Baker RK, Kieffer TJ. Leptin contributes to the beneficial effects of insulin treatment in streptozotocin-diabetic male mice. Am J Physiol Endocrinol Metab 2018; 315:E1264-E1273. [PMID: 30300012 DOI: 10.1152/ajpendo.00159.2018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It was long thought that the only hormone capable of reversing the catabolic consequences of diabetes was insulin. However, various studies have demonstrated that the adipocyte-derived hormone leptin can robustly lower blood glucose levels in rodent models of insulin-deficient diabetes. In addition, it has been suggested that some of the metabolic manifestations of insulin-deficient diabetes are due to hypoleptinemia as opposed to hypoinsulinemia. Because insulin therapy increases leptin levels, we sought to investigate the contribution of leptin to the beneficial effects of insulin therapy. To do this, we tested insulin therapy in streptozotocin (STZ) diabetic mice that were either on an ob/ ob background or that were given a leptin antagonist to determine if blocking leptin action would blunt the glucose-lowering effects of insulin therapy. We found that STZ diabetic ob/ ob mice have a diminished blood glucose-lowering effect in response to insulin therapy compared with STZ diabetic controls and exhibited more severe weight loss post-STZ injection. In addition, STZ diabetic mice administered a leptin antagonist through daily injection or plasmid expression respond less robustly to insulin therapy as assessed by both fasting blood glucose levels and blood glucose levels during an oral glucose tolerance test. However, leptin antagonism did not prevent the insulin-induced reduction in β-hydroxybutyrate and triglyceride levels. Therefore, we conclude that elevated leptin levels can contribute to the glucose-lowering effect of insulin therapy in insulin-deficient diabetes.
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Affiliation(s)
- Ursula H Neumann
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia , Vancouver, British Columbia , Canada
| | - Michelle M Kwon
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia , Vancouver, British Columbia , Canada
| | - Robert K Baker
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia , Vancouver, British Columbia , Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia , Vancouver, British Columbia , Canada
- Department of Surgery, Life Sciences Institute, University of British Columbia , Vancouver, British Columbia , Canada
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62
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Fijany A, Sayadi LR, Khoshab N, Banyard DA, Shaterian A, Alexander M, Lakey JRT, Paydar KZ, Evans GRD, Widgerow AD. Mesenchymal stem cell dysfunction in diabetes. Mol Biol Rep 2018; 46:1459-1475. [PMID: 30484107 DOI: 10.1007/s11033-018-4516-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/22/2018] [Indexed: 02/08/2023]
Abstract
Diabetes mellitus (DM) is a chronic disease that results in a variety of systemic complications. Recently, stem cell-based therapies have been proposed as potential modalities to manage DM related complications. Mesenchymal stem cell (MSC) based therapies are often considered as an ideal stem cell-based treatment for DM management due to their immunosuppressive characteristics, anti-inflammatory properties and differentiation potential. While MSCs show tremendous promise, the underlying functional deficits of MSCs in DM patients is not well understood. Using the MEDLINE database to define these functional deficits, our search yielded 1826 articles of which 33 met our inclusion criteria. This allowed us to review the topic and illuminate four major molecular categories by which MSCs are compromised in both Type 1 DM and Type II DM models which include: (1) changes in angiogenesis/vasculogenesis, (2) altered pro-inflammatory cytokine secretion, (3) increased oxidative stress markers and (4) impaired cellular differentiation and decreased proliferation. Knowledge of the deficits in MSC function will allow us to more clearly assess the efficacy of potential biologic therapies for reversing these dysfunctions when treating the complications of diabetic disease.
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Affiliation(s)
- Arman Fijany
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA
| | - Lohrasb R Sayadi
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA
| | - Nima Khoshab
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA
| | - Derek A Banyard
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA
| | - Ashkaun Shaterian
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA
| | - Michael Alexander
- UC Irvine Department of Surgery & Biomedical Engineering, Orange, CA, USA
| | | | - Keyianoosh Z Paydar
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA
| | - Gregory R D Evans
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA.,UC Irvine Department of Surgery & Biomedical Engineering, Orange, CA, USA
| | - Alan D Widgerow
- UC Irvine Department of Plastic Surgery, Center for Tissue Engineering, Orange, CA, USA. .,UC Irvine Department of Surgery & Biomedical Engineering, Orange, CA, USA. .,University of California, Irvine Suite 108a Building 55, 101 S. City Dr., Orange, CA, 92868, USA.
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63
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Petersen MC, Shulman GI. Mechanisms of Insulin Action and Insulin Resistance. Physiol Rev 2018; 98:2133-2223. [PMID: 30067154 PMCID: PMC6170977 DOI: 10.1152/physrev.00063.2017] [Citation(s) in RCA: 1448] [Impact Index Per Article: 241.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/22/2018] [Accepted: 03/24/2018] [Indexed: 12/15/2022] Open
Abstract
The 1921 discovery of insulin was a Big Bang from which a vast and expanding universe of research into insulin action and resistance has issued. In the intervening century, some discoveries have matured, coalescing into solid and fertile ground for clinical application; others remain incompletely investigated and scientifically controversial. Here, we attempt to synthesize this work to guide further mechanistic investigation and to inform the development of novel therapies for type 2 diabetes (T2D). The rational development of such therapies necessitates detailed knowledge of one of the key pathophysiological processes involved in T2D: insulin resistance. Understanding insulin resistance, in turn, requires knowledge of normal insulin action. In this review, both the physiology of insulin action and the pathophysiology of insulin resistance are described, focusing on three key insulin target tissues: skeletal muscle, liver, and white adipose tissue. We aim to develop an integrated physiological perspective, placing the intricate signaling effectors that carry out the cell-autonomous response to insulin in the context of the tissue-specific functions that generate the coordinated organismal response. First, in section II, the effectors and effects of direct, cell-autonomous insulin action in muscle, liver, and white adipose tissue are reviewed, beginning at the insulin receptor and working downstream. Section III considers the critical and underappreciated role of tissue crosstalk in whole body insulin action, especially the essential interaction between adipose lipolysis and hepatic gluconeogenesis. The pathophysiology of insulin resistance is then described in section IV. Special attention is given to which signaling pathways and functions become insulin resistant in the setting of chronic overnutrition, and an alternative explanation for the phenomenon of ‟selective hepatic insulin resistanceˮ is presented. Sections V, VI, and VII critically examine the evidence for and against several putative mediators of insulin resistance. Section V reviews work linking the bioactive lipids diacylglycerol, ceramide, and acylcarnitine to insulin resistance; section VI considers the impact of nutrient stresses in the endoplasmic reticulum and mitochondria on insulin resistance; and section VII discusses non-cell autonomous factors proposed to induce insulin resistance, including inflammatory mediators, branched-chain amino acids, adipokines, and hepatokines. Finally, in section VIII, we propose an integrated model of insulin resistance that links these mediators to final common pathways of metabolite-driven gluconeogenesis and ectopic lipid accumulation.
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Affiliation(s)
- Max C Petersen
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
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64
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Li J, Shen X. Leptin concentration and oxidative stress in diabetic ketoacidosis. Eur J Clin Invest 2018; 48:e13006. [PMID: 30053313 DOI: 10.1111/eci.13006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/25/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND Diabetes is a common metabolic state during ageing, and one in five elderly individuals suffers from diabetes. However, few studies have been performed in elderly diabetic patients, and large randomized clinical trials in this population are rare. The purpose of this study was to investigate changes in serum leptin levels in elderly patients with diabetic ketoacidosis (DKA) before and after treatment and assess its relationship with oxidative stress parameters. MATERIALS AND METHODS Serum leptin levels, plasma superoxide dismutase (SOD) activity, plasma malondialdehyde (MDA) levels, plasma total antioxidant capacity (TAC) and plasma 8-iso-prostaglandin F2α (8-iso-PGF2α ) levels were measured in elderly patients aged 81.76 ± 9.42 years with DKA before and after treatment. RESULTS Plasma SOD activity, TAC and serum leptins before treatment were significantly lower in elderly patients with DKA compared with the control group (P < 0.05), whereas plasma MDA and 8-iso-PGF2α levels before treatment were significantly higher in elderly patients with DKA (P < 0.05). Plasma SOD activity, TAC and serum leptin levels in elderly patients with DKA were significantly elevated after treatment, whereas their plasma MDA and 8-iso-PGF2α levels were significantly reduced (P < 0.05). Leptin levels negatively correlated with plasma 8-iso-PGF2α after treatment in elderly DKA patients (r = -0.36, P < 0.05). Stepwise multiple regression analysis showed that 8-iso-PGF2α was a significant factor affecting serum leptin levels. CONCLUSIONS Serum leptin levels in the elderly patients with DKA were significantly reduced after treatment, which was associated with oxidative stress.
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Affiliation(s)
- Juan Li
- Department of Emergency, Zhongshan Hospital Xiamen University, Xiamen, China
| | - Xingping Shen
- Department of Endocrinology, Zhongshan Hospital Xiamen University, Xiamen, China
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65
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Bak AM, Vendelbo MH, Christensen B, Viggers R, Bibby BM, Rungby J, Jørgensen JOL, Møller N, Jessen N. Prolonged fasting-induced metabolic signatures in human skeletal muscle of lean and obese men. PLoS One 2018; 13:e0200817. [PMID: 30183740 PMCID: PMC6124727 DOI: 10.1371/journal.pone.0200817] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 07/03/2018] [Indexed: 11/19/2022] Open
Abstract
Insulin resistance is a well-known physiological adaptation to prolonged fasting in healthy skeletal muscle. Obesity is associated with insulin resistance and metabolic inflexibility in skeletal muscle, and a pronounced increase in the risk of metabolic complications. Under the hypothesis that the metabolic traits of insulin resistance associated with prolonged fasting are different from insulin resistance associated with obesity, we examined nine obese and nine lean participants during 12 and 72h of fasting, respectively. Insulin resistance in obese participants was associated with impaired insulin signaling, and reduced levels of glucose-6-phosphate and TCA-cycle intermediates. 72h of fasting in lean participants reduced insulin-stimulated glucose uptake to levels similar to obese participants fasted for 12h. This was associated with increased lipid oxidation, but not accumulation of diacylglycerol or acylcarnitines and impairment of insulin signaling. Prolonged fasting was associated with pronounced increases in β-hydroxybutyrate and β- hydroxybutyrylcarnitine levels in skeletal muscle suggesting augmented ketone body metabolism. Fasting induced insulin resistance may be a consequence of substrate competition. The underlying mechanism behind insulin resistance in obesity is thus not comparable to the physiological adaptations in skeletal muscle induced by prolonged fasting in lean participants.
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Affiliation(s)
- Ann Mosegaard Bak
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, Aarhus, Denmark
- * E-mail:
| | - Mikkel Holm Vendelbo
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, Aarhus, Denmark
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Rikke Viggers
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Bo Martin Bibby
- Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Jørgen Rungby
- Department of Biomedicine, Aarhus University, Denmark
| | - Jens Otto Lunde Jørgensen
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, Aarhus, Denmark
| | - Niels Møller
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, Aarhus, Denmark
| | - Niels Jessen
- Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Denmark
- Department of Clinical Pharmacology, Aarhus University Hospital, Denmark
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66
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Christen T, Trompet S, Noordam R, van Klinken JB, van Dijk KW, Lamb HJ, Cobbaert CM, den Heijer M, Jazet IM, Jukema JW, Rosendaal FR, de Mutsert R. Sex differences in body fat distribution are related to sex differences in serum leptin and adiponectin. Peptides 2018; 107:25-31. [PMID: 30076861 DOI: 10.1016/j.peptides.2018.07.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/23/2018] [Accepted: 07/29/2018] [Indexed: 01/01/2023]
Abstract
It is debated whether sex differences in adiponectin and leptin are due to sex differences in body fat distribution. In this cross-sectional analysis of the Netherlands Epidemiology of Obesity study, associations of measures of body fat and sex with serum adiponectin and leptin concentrations were examined using linear regression analysis (n = 6494, VAT: n = 2516). Sex differences were additionally adjusted for the measure of body fat that was most strongly associated with adiponectin or leptin concentrations. Median adiponectin concentrations in women and men were 10.5 mg/L (IQR, interquartile range: 7.7-13.9) and 6.1 mg/L (IQR: 4.5-8.2), mean difference 4.6 mg/L (95% CI: 4.3, 4.9). Median leptin concentrations in women and men were 19.2 μg/L (IQR: 11.5-30.0) and 7.1 μg/L (IQR: 4.6-11.1), mean difference 15.1 μg/L (95% CI: 14.4, 15.8). VAT was most strongly associated with adiponectin, total body fat percentage was most strongly associated with leptin. After adjustment for VAT, women had 3.8 mg/L (95% CI: 3.3, 4.3) higher adiponectin than men. After adjustment for total body fat percentage, leptin concentrations in women were 0.4 μg/L lower than in men (95% CI: -1.2, 2.0). One genetic variant (rs4731420) was associated with extreme leptin concentrations (>100 μg/L) in women: odds ratio 2.8 (95% CI: 1.7, 4.6). Total body fat percentage was strongly associated with leptin concentrations. Higher leptin concentrations in women than in men were completely explained by differences in total body fat percentage. Visceral fat was associated with adiponectin concentrations, and did not completely explain higher adiponectin concentrations in women than in men.
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Affiliation(s)
- Tim Christen
- Department of Clinical Epidemiology, Leiden University Medical Center (LUMC), PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Stella Trompet
- Department of Internal Medicine, Section of Gerontology and Geriatrics, PO-Box 9600, 2300RC, LUMC, Leiden, The Netherlands; Department of Cardiology, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Raymond Noordam
- Department of Internal Medicine, Section of Gerontology and Geriatrics, PO-Box 9600, 2300RC, LUMC, Leiden, The Netherlands
| | - Jan B van Klinken
- Department of Human Genetics, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Ko Willems van Dijk
- Department of Human Genetics, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands; Department of Medicine, Division of Endocrinology, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands; Einthoven Laboratory for Vascular and Regenerative Medicine, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Hildo J Lamb
- Department of Radiology, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Christa M Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Martin den Heijer
- Department of Clinical Epidemiology, Leiden University Medical Center (LUMC), PO-Box 9600, 2300RC, Leiden, The Netherlands; Department of Internal Medicine, VU Medical Center, PO-Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - Ingrid M Jazet
- Department of Medicine, Division of Endocrinology, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - J Wouter Jukema
- Department of Cardiology, LUMC, PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Frits R Rosendaal
- Department of Clinical Epidemiology, Leiden University Medical Center (LUMC), PO-Box 9600, 2300RC, Leiden, The Netherlands
| | - Renée de Mutsert
- Department of Clinical Epidemiology, Leiden University Medical Center (LUMC), PO-Box 9600, 2300RC, Leiden, The Netherlands.
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67
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Madiraju AK, Qiu Y, Perry RJ, Rahimi Y, Zhang XM, Zhang D, Camporez JPG, Cline GW, Butrico GM, Kemp BE, Casals G, Steinberg GR, Vatner DF, Petersen KF, Shulman GI. Metformin inhibits gluconeogenesis via a redox-dependent mechanism in vivo. Nat Med 2018; 24:1384-1394. [PMID: 30038219 PMCID: PMC6129196 DOI: 10.1038/s41591-018-0125-4] [Citation(s) in RCA: 184] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 06/04/2018] [Indexed: 02/07/2023]
Abstract
Metformin, the universal first-line treatment for type 2 diabetes, exerts its therapeutic glucose-lowering effects by inhibiting hepatic gluconeogenesis. However, the primary molecular mechanism of this biguanide remains unclear, though it has been suggested to act, at least partially, by mitochondrial complex I inhibition. Here we show that clinically relevant concentrations of plasma metformin achieved by acute intravenous, acute intraportal or chronic oral administration in awake normal and diabetic rats inhibit gluconeogenesis from lactate and glycerol but not from pyruvate and alanine, implicating an increased cytosolic redox state in mediating metformin's antihyperglycemic effect. All of these effects occurred independently of complex I inhibition, evidenced by unaltered hepatic energy charge and citrate synthase flux. Normalizing the cytosolic redox state by infusion of methylene blue or substrates that contribute to gluconeogenesis independently of the cytosolic redox state abrogated metformin-mediated inhibition of gluconeogenesis in vivo. Additionally, in mice expressing constitutively active acetyl-CoA carboxylase, metformin acutely decreased hepatic glucose production and increased the hepatic cytosolic redox state without altering hepatic triglyceride content or gluconeogenic enzyme expression. These studies demonstrate that metformin, at clinically relevant plasma concentrations, inhibits hepatic gluconeogenesis in a redox-dependent manner independently of reductions in citrate synthase flux, hepatic nucleotide concentrations, acetyl-CoA carboxylase activity, or gluconeogenic enzyme protein expression.
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Affiliation(s)
- Anila K Madiraju
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
- Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA
| | - Yang Qiu
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
- Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Rachel J Perry
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Yasmeen Rahimi
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Xian-Man Zhang
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Dongyan Zhang
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | | | - Gary W Cline
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Gina M Butrico
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Bruce E Kemp
- St. Vincent's Institute of Medical Research and Department of Medicine, University of Melbourne & Mary MacKillop Institute for Health Research, Australian Catholic University Fitzroy, Fitzroy, Victoria, Australia
| | - Gregori Casals
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Gregory R Steinberg
- Departments of Medicine and Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Daniel F Vatner
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Kitt F Petersen
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Gerald I Shulman
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA.
- Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA.
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68
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Steinhauser ML, Olenchock BA, O'Keefe J, Lun M, Pierce KA, Lee H, Pantano L, Klibanski A, Shulman GI, Clish CB, Fazeli PK. The circulating metabolome of human starvation. JCI Insight 2018; 3:121434. [PMID: 30135314 DOI: 10.1172/jci.insight.121434] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/10/2018] [Indexed: 12/17/2022] Open
Abstract
The human adaptive starvation response allows for survival during long-term caloric deprivation. Whether the physiology of starvation is adaptive or maladaptive is context dependent: activation of pathways by caloric restriction may promote longevity, yet in the context of caloric excess, the same pathways may contribute to obesity. Here, we performed plasma metabolite profiling of longitudinally collected samples during a 10-day, 0-calorie fast in humans. We identify classical milestones in adaptive starvation, including the early consumption of gluconeogenic amino acids and the subsequent surge in plasma nonesterified fatty acids that marks the shift from carbohydrate to lipid metabolism, and demonstrate findings, including (a) the preferential release of unsaturated fatty acids and an associated shift in plasma lipid species with high degrees of unsaturation and (b) evidence that acute, starvation-mediated hypoleptinemia may be a driver of the transition from glucose to lipid metabolism in humans.
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Affiliation(s)
- Matthew L Steinhauser
- Department of Medicine, Division of Genetics, and.,Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Benjamin A Olenchock
- Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - John O'Keefe
- Department of Medicine, Division of Genetics, and
| | - Mingyue Lun
- Department of Medicine, Division of Genetics, and
| | - Kerry A Pierce
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Hang Lee
- Harvard Medical School, Boston, Massachusetts, USA.,MGH Biostatistics Center, Boston, Massachusetts, USA
| | - Lorena Pantano
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Anne Klibanski
- Harvard Medical School, Boston, Massachusetts, USA.,Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular and Molecular Physiology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Clary B Clish
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Pouneh K Fazeli
- Harvard Medical School, Boston, Massachusetts, USA.,Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
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69
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Kadota R, Sugita K, Uchida K, Yamada H, Yamashita M, Kimura H. A mathematical model of type 1 diabetes involving leptin effects on glucose metabolism. J Theor Biol 2018; 456:213-223. [PMID: 30098320 DOI: 10.1016/j.jtbi.2018.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 08/03/2018] [Accepted: 08/06/2018] [Indexed: 12/14/2022]
Abstract
Leptin, a hormone released from fat cells in adipose tissues, was recently found to be capable of normalizing glucose metabolism in animals. Clinical data on patients with lipodystrophy indicates that leptin may have a positive effect on glucose metabolism in individuals with diabetes. There are growing expectations that leptin can improve the current insulin treatment for patients with type 1 diabetes. We investigated this possibility through in silico experiments based on a mathematical model of diabetes, which is currently the only mode of research that eliminates human risk. A model of the brain-centered glucoregulatory system, in which leptin plays a central role, was constructed and integrated within a conventional model of insulin/glucose dynamics. The model has been validated using experimental data from animal studies. The in silico combination experiments showed excellent therapeutic performance over insulin monotherapy.
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Affiliation(s)
- Rei Kadota
- Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo, Japan
| | - Kazuma Sugita
- Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo, Japan
| | - Kenko Uchida
- Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo, Japan
| | - Hitoshi Yamada
- TOYOTA MOTOR CORPORATION, 1, Toyota-cho, Toyota, Aichi, Japan
| | | | - Hidenori Kimura
- Faculty of Science and Engineering, Waseda University, Building 55S, Room 706A, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
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70
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Perry RJ. Leptin revisited: The role of leptin in starvation. Mol Cell Oncol 2018; 5:e1435185. [PMID: 30263938 PMCID: PMC6154858 DOI: 10.1080/23723556.2018.1435185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 11/29/2022]
Abstract
Starvation causes reductions in plasma leptin concentrations, but the physiologic impact of this observation had not been documented in the starved state. Here we discuss our recent work demonstrating that hypoleptinemia activates the hypothalamic-pituitary-adrenal (HPA) axis, increasing white adipose tissue (WAT) lipolysis and mediating a shift from glucose to fat metabolism to maintain euglycemia in fasted rats.
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Affiliation(s)
- Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT
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71
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Della Guardia L, Thomas MA, Cena H. Insulin Sensitivity and Glucose Homeostasis Can Be Influenced by Metabolic Acid Load. Nutrients 2018; 10:E618. [PMID: 29762478 PMCID: PMC5986498 DOI: 10.3390/nu10050618] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/08/2018] [Accepted: 05/10/2018] [Indexed: 01/04/2023] Open
Abstract
Recent epidemiological findings suggest that high levels of dietary acid load can affect insulin sensitivity and glucose metabolism. Consumption of high protein diets results in the over-production of metabolic acids which has been associated with the development of chronic metabolic disturbances. Mild metabolic acidosis has been shown to impair peripheral insulin action and several epidemiological findings suggest that metabolic acid load markers are associated with insulin resistance and impaired glycemic control through an interference intracellular insulin signaling pathways and translocation. In addition, higher incidence of diabetes, insulin resistance, or impaired glucose control have been found in subjects with elevated metabolic acid load markers. Hence, lowering dietary acid load may be relevant for improving glucose homeostasis and prevention of type 2 diabetes development on a long-term basis. However, limitations related to patient acid load estimation, nutritional determinants, and metabolic status considerably flaws available findings, and the lack of solid data on the background physiopathology contributes to the questionability of results. Furthermore, evidence from interventional studies is very limited and the trials carried out report no beneficial results following alkali supplementation. Available literature suggests that poor acid load control may contribute to impaired insulin sensitivity and glucose homeostasis, but it is not sufficiently supportive to fully elucidate the issue and additional well-designed studies are clearly needed.
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Affiliation(s)
- Lucio Della Guardia
- Laboratory of Dietetics and Clinical Nutrition Department of Public Health, Experimental and Forensic Medicine, University of Pavia, 27100 Pavia, Italy.
| | - Michael Alex Thomas
- Department of Biology, Center for Obesity Reversal, Georgia State University, Atlanta, GA 30302, USA.
| | - Hellas Cena
- Laboratory of Dietetics and Clinical Nutrition Department of Public Health, Experimental and Forensic Medicine, University of Pavia, 27100 Pavia, Italy.
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72
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Bocchio-Chiavetto L, Zanardini R, Tosato S, Ventriglia M, Ferrari C, Bonetto C, Lasalvia A, Giubilini F, Fioritti A, Pileggi F, Pratelli M, Pavanati M, Favaro A, De Girolamo G, Frisoni GB, Ruggeri M, Gennarelli M. Immune and metabolic alterations in first episode psychosis (FEP) patients. Brain Behav Immun 2018; 70:315-324. [PMID: 29548996 DOI: 10.1016/j.bbi.2018.03.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 03/09/2018] [Accepted: 03/11/2018] [Indexed: 12/14/2022] Open
Abstract
The molecular underpinnings associated to first episode psychosis (FEP) remains to be elucidated, but compelling evidence supported an association of FEP with blood alterations in biomarkers related to immune system, growth factors and metabolism regulators. Many of these studies have not been already confirmed in larger samples or have not considered the FEP diagnostic subgroups. In order to identify biochemical signatures of FEP, the serum levels of the growth factors BDNF and VEGF, the immune regulators IL-1RA, IL-6, IL-10 and IL-17, RANTES/CCL5, MIP-1b/CCL4, IL-8 and the metabolic regulators C-peptide, ghrelin, GIP, GLP-1, glucagon, insulin, leptin, PAI-1, resistin and visfatin were analysed in 260 subjects collected in the GET UP project. The results indicated an increase of MIP-1b/CCL4, VEGF, IL-6 and PAI-1, while IL-17, ghrelin, glucagon and GLP-1 were decreased in the whole sample of FEP patients (p < 0.01 for all markers except for PAI-1 p < 0.05). No differences were evidenced for these markers among the diagnostic groups that constitute the FEP sample, whereas IL-8 is increased only in patients with a diagnosis of affective psychosis. The principal component analysis (PCA) and variable importance analysis (VIA) indicated that MIP-1b/CCL4, ghrelin, glucagon, VEGF and GLP-1 were the variables mostly altered in FEP patients. On the contrary, none of the analysed markers nor a combination of them can discriminate between FEP diagnostic subgroups. These data evidence a profile of immune and metabolic alterations in FEP patients, providing new information on the molecular mechanism associated to the psychosis onset for the development of preventive strategies and innovative treatment targets.
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Affiliation(s)
- Luisella Bocchio-Chiavetto
- IRCCS Centro S. Giovanni di Dio, Fatebenefratelli, Brescia, Italy; Faculty of Psychology, eCampus University, Novedrate (Como), Italy.
| | | | - Sarah Tosato
- Section of Psychiatry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Mariacarla Ventriglia
- Fatebenefratelli Foundation, AFaR Division, Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy
| | - Clarissa Ferrari
- IRCCS Centro S. Giovanni di Dio, Fatebenefratelli, Brescia, Italy
| | - Chiara Bonetto
- Section of Psychiatry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Antonio Lasalvia
- Unit of Psychiatry, Azienda Ospedaliera Universitaria Integrata (AOUI), Verona, Italy
| | | | | | | | | | - Michele Pavanati
- Department of Medical Sciences of Communication and Behavior, Section of Psychiatry, The Consultation-Liaison Psychiatric Service and Psychiatric Unit, University of Ferrara, Italy
| | - Angela Favaro
- Department of Neurosciences, University of Padua and Azienda Ospedaliera, Padua, Italy
| | | | - Giovanni Battista Frisoni
- IRCCS Centro S. Giovanni di Dio, Fatebenefratelli, Brescia, Italy; Geneva University Hospital and University of Geneva, Switzerland
| | - Mirella Ruggeri
- Section of Psychiatry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Massimo Gennarelli
- IRCCS Centro S. Giovanni di Dio, Fatebenefratelli, Brescia, Italy; Dept. of Molecular and Translational Medicine, Division of Biology and Genetics, University of Brescia, Italy
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73
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La Cava A. Leptin in inflammation and autoimmunity. Cytokine 2018; 98:51-58. [PMID: 27916613 DOI: 10.1016/j.cyto.2016.10.011] [Citation(s) in RCA: 214] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 12/11/2022]
Abstract
After its discovery as a key controller of metabolic function, leptin has been later extensively implicated in additional functions including important modulatory activities on the innate and adaptive immune response. This review analyzes the known implications of leptin in multiple inflammatory conditions, including autoimmune diseases, and how this knowledge could be instrumental in the design of leptin-based manipulation strategies to help restoration of abnormal immune responses.
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Affiliation(s)
- Antonio La Cava
- Department of Medicine, University of California Los Angeles, 1000 Veteran Ave. 32-59, Los Angeles, CA 90095, United States.
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74
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Xu J, Bartolome CL, Low CS, Yi X, Chien CH, Wang P, Kong D. Genetic identification of leptin neural circuits in energy and glucose homeostases. Nature 2018; 556:505-509. [PMID: 29670283 PMCID: PMC5920723 DOI: 10.1038/s41586-018-0049-7] [Citation(s) in RCA: 187] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 03/19/2018] [Indexed: 12/16/2022]
Abstract
Leptin, a hormone produced in white adipose tissue, acts in the brain to communicate fuel status, suppress appetite following a meal, promote energy expenditure, and maintain blood glucose stability1,2. Dysregulations of leptin or its receptors (LepR) result in severe obesity and diabetes3–5. Although intensive studies on leptin have transformed obesity and diabetes research2,6, clinical applications of the molecule are still limited7 which, at least in part, is due to the complexity and our incomplete understanding of the underlying neural circuits. The hypothalamic neurons expressing agouti-related peptide (AgRP) and proopiomelanocortin (POMC) were posited as the first-order leptin-responsive neurons. Selective deletion of LepR in these neurons with Cre-loxP system, however, failed to or marginally recapitulated obesity and diabetes in LepR-deficient Leprdb/db mice, suggesting that AgRP or POMC neurons are not directly required8–10. The primary neural targets for leptin are thus still unclear. Here, we conduct a systematic, unbiased survey of leptin-responsive neurons in streptozotocin (STZ)-induced diabetic mice and exploit CRISPR/Cas9-mediated genetic ablation of LepR in vivo. Unexpectedly, we find that AgRP neurons but not POMC neurons integrate the primary action of leptin to regulate both energy balance and glucose homeostasis. Leptin deficiency disinhibits AgRP neurons, and their chemogenetic inhibition reverses both diabetic hyperphagia and hyperglycemia. In sharp contrast with prior studies, we show that CRISPR-mediated deletion of LepR in AgRP neurons causes severe obesity and diabetes, fatefully replicating the phenotype of Leprdb/db mice. We also uncover divergent mechanisms underlying leptin’s acute and chronic inhibition of AgRP neurons (i.e., presynaptic potentiation of GABAergic neurotransmission and postsynaptic activation of ATP-sensitive potassium channels, respectively). Our findings provide the framework underlying the neurobiological mechanisms of leptin and associated metabolic disorders.
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Affiliation(s)
- Jie Xu
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Christopher L Bartolome
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA.,Program of Neuroscience, Tufts University Sackler School of Graduate Biomedical Sciences, Boston, MA, USA
| | - Cho Shing Low
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA.,Program of Cellular, Molecular, and Developmental Biology, Tufts University Sackler School of Graduate Biomedical Sciences, Boston, MA, USA
| | - Xinchi Yi
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Cheng-Hao Chien
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Peng Wang
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Dong Kong
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA. .,Program of Neuroscience, Tufts University Sackler School of Graduate Biomedical Sciences, Boston, MA, USA. .,Program of Cellular, Molecular, and Developmental Biology, Tufts University Sackler School of Graduate Biomedical Sciences, Boston, MA, USA.
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75
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Meek TH, Matsen ME, Faber CL, Samstag CL, Damian V, Nguyen HT, Scarlett JM, Flak JN, Myers MG, Morton GJ. In Uncontrolled Diabetes, Hyperglucagonemia and Ketosis Result From Deficient Leptin Action in the Parabrachial Nucleus. Endocrinology 2018; 159:1585-1594. [PMID: 29438473 PMCID: PMC5939636 DOI: 10.1210/en.2017-03199] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 01/25/2018] [Indexed: 12/17/2022]
Abstract
Growing evidence implicates neurons that project from the lateral parabrachial nucleus (LPBN) to the hypothalamic ventromedial nucleus (VMN) in a neurocircuit that drives counterregulatory responses to hypoglycemia, including increased glucagon secretion. Among LPBN neurons in this circuit is a subset that expresses cholecystokinin (LPBNCCK neurons) and is tonically inhibited by leptin. Because uncontrolled diabetes is associated with both leptin deficiency and hyperglucagonemia, and because intracerebroventricular (ICV) leptin administration reverses both hyperglycemia and hyperglucagonemia in this setting, we hypothesized that deficient leptin inhibition of LPBNCCK neurons drives activation of this LPBN→VMN circuit and thereby results in hyperglucagonemia. Here, we report that although bilateral microinjection of leptin into the LPBN does not ameliorate hyperglycemia in rats with streptozotocin-induced diabetes mellitus (STZ-DM), it does attenuate the associated hyperglucagonemia and ketosis. To determine if LPBN leptin signaling is required for the antidiabetic effect of ICV leptin in STZ-DM, we studied mice in which the leptin receptor was selectively deleted from LPBNCCK neurons. Our findings show that although leptin signaling in these neurons is not required for the potent antidiabetic effect of ICV leptin, it is required for leptin-mediated suppression of diabetic hyperglucagonemia. Taken together, these findings suggest that leptin-mediated effects in animals with uncontrolled diabetes occur through actions involving multiple brain areas, including the LPBN, where leptin acts specifically to inhibit glucagon secretion and associated ketosis.
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Affiliation(s)
- Thomas H Meek
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
| | - Miles E Matsen
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
| | - Chelsea L Faber
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
| | - Colby L Samstag
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
| | - Vincent Damian
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
| | - Hong T Nguyen
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
| | - Jarrad M Scarlett
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
| | - Jonathan N Flak
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Gregory J Morton
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, Washington
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76
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Perry RJ, Shulman GI. The Role of Leptin in Maintaining Plasma Glucose During Starvation. POSTDOC JOURNAL : A JOURNAL OF POSTDOCTORAL RESEARCH AND POSTDOCTORAL AFFAIRS 2018; 6:3-19. [PMID: 29682594 PMCID: PMC5909716 DOI: 10.14304/surya.jpr.v6n3.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
For 20 years it has been known that concentrations of leptin, a hormone produced by the white adipose tissue (WAT) largely in proportion to body fat, drops precipitously with starvation, particularly in lean humans and animals. The role of leptin to suppress the thyroid and reproductive axes during a prolonged fast has been well defined; however, the impact of leptin on metabolic regulation has been incompletely understood. However emerging evidence suggests that, in starvation, hypoleptinemia increases activity of the hypothalamic-pituitary-adrenal axis, promoting WAT lipolysis, increasing hepatic acetyl-CoA concentrations, and maintaining euglycemia. In addition, leptin may be largely responsible for mediating a shift from a reliance upon glucose metabolism (absorption and glycogenolysis) to fat metabolism (lipolysis increasing gluconeogenesis) which preserves substrates for the brain, heart, and other critical organs. In this way a leptin-mediated glucose-fatty acid cycle appears to maintain glycemia and permit survival in starvation.
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Affiliation(s)
- Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine
- Department of Cellular & Molecular Physiology, Yale University School of Medicine
- Howard Hughes Medical Institute
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77
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Abstract
Sepsis is a life-threatening organ dysfunction caused by a deregulated host response to infection. This inappropriate response to micro-organism invasion is characterized by an overwhelmed systemic inflammatory response and cardiovascular collapse that culminate in high mortality and morbidity in critical care units. The occurrence of sepsis in diabetes mellitus (DM) patients has become more frequent, as the prevalence of DM has increased dramatically worldwide. These two important diseases represent a global public health concern and highlight the importance of increasing our knowledge of the key elements of the immune response related to both conditions. In this context, it is well established that the cells taking part in the innate and adaptive immune responses in diabetic patients have compromised function. These altered responses favor micro-organism growth, a process that contributes to sepsis progression. The present review provides an update on the characteristics of the immune system in diabetic and septic subjects. We also explore the beneficial effects of insulin on the immune response in a glycemic control-dependent and independent manner.
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78
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Lao-On U, Attwood PV, Jitrapakdee S. Roles of pyruvate carboxylase in human diseases: from diabetes to cancers and infection. J Mol Med (Berl) 2018; 96:237-247. [PMID: 29362846 DOI: 10.1007/s00109-018-1622-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 02/08/2023]
Abstract
Pyruvate carboxylase (PC), an anaplerotic enzyme, plays an essential role in various cellular metabolic pathways including gluconeogenesis, de novo fatty acid synthesis, amino acid synthesis, and glucose-induced insulin secretion. Deregulation of PC expression or activity has long been known to be associated with metabolic syndrome in several rodent models. Accumulating data in the past decade clearly showed that deregulation of PC expression is associated with type 2 diabetes in humans, while targeted inhibition of PC expression in a mouse model reduced adiposity and improved insulin sensitivity in diet-induced type 2 diabetes. More recent studies also show that PC is strongly involved in tumorigenesis in several cancers, including breast, non-small cell lung cancer, glioblastoma, renal carcinoma, and gall bladder. Systems metabolomics analysis of these cancers identified pyruvate carboxylation as an essential metabolic hub that feeds carbon skeletons of downstream metabolites of oxaloacetate into the biosynthesis of various cellular components including membrane lipids, nucleotides, amino acids, and the redox control. Inhibition or down-regulation of PC expression in several cancers markedly impairs their growth ex vivo and in vivo, drawing attention to PC as an anti-cancer target. PC has also exhibited a moonlight function by interacting with immune surveillance that can either promote or block viral infection. In certain pathogenic bacteria, PC is essential for infection, replication, and maintenance of their virulence phenotype.
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Affiliation(s)
- Udom Lao-On
- Gene Expression and Metabolic Science Research Laboratory, Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Paul V Attwood
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Sarawut Jitrapakdee
- Gene Expression and Metabolic Science Research Laboratory, Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
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79
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Perry RJ, Wang Y, Cline GW, Rabin-Court A, Song JD, Dufour S, Zhang XM, Petersen KF, Shulman GI. Leptin Mediates a Glucose-Fatty Acid Cycle to Maintain Glucose Homeostasis in Starvation. Cell 2018; 172:234-248.e17. [PMID: 29307489 PMCID: PMC5766366 DOI: 10.1016/j.cell.2017.12.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/09/2017] [Accepted: 11/29/2017] [Indexed: 02/02/2023]
Abstract
The transition from the fed to the fasted state necessitates a shift from carbohydrate to fat metabolism that is thought to be mostly orchestrated by reductions in plasma insulin concentrations. Here, we show in awake rats that insulinopenia per se does not cause this transition but that both hypoleptinemia and insulinopenia are necessary. Furthermore, we show that hypoleptinemia mediates a glucose-fatty acid cycle through activation of the hypothalamic-pituitary-adrenal axis, resulting in increased white adipose tissue (WAT) lipolysis rates and increased hepatic acetyl-coenzyme A (CoA) content, which are essential to maintain gluconeogenesis during starvation. We also show that in prolonged starvation, substrate limitation due to reduced rates of glucose-alanine cycling lowers rates of hepatic mitochondrial anaplerosis, oxidation, and gluconeogenesis. Taken together, these data identify a leptin-mediated glucose-fatty acid cycle that integrates responses of the muscle, WAT, and liver to promote a shift from carbohydrate to fat oxidation and maintain glucose homeostasis during starvation.
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Affiliation(s)
- Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Yongliang Wang
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Gary W Cline
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Aviva Rabin-Court
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Joongyu D Song
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sylvie Dufour
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Xian Man Zhang
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Kitt Falk Petersen
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA.
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80
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Samuel VT, Shulman GI. Nonalcoholic Fatty Liver Disease as a Nexus of Metabolic and Hepatic Diseases. Cell Metab 2018; 27:22-41. [PMID: 28867301 PMCID: PMC5762395 DOI: 10.1016/j.cmet.2017.08.002] [Citation(s) in RCA: 470] [Impact Index Per Article: 78.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/01/2017] [Accepted: 08/01/2017] [Indexed: 12/15/2022]
Abstract
NAFLD is closely linked with hepatic insulin resistance. Accumulation of hepatic diacylglycerol activates PKC-ε, impairing insulin receptor activation and insulin-stimulated glycogen synthesis. Peripheral insulin resistance indirectly influences hepatic glucose and lipid metabolism by increasing flux of substrates that promote lipogenesis (glucose and fatty acids) and gluconeogenesis (glycerol and fatty acid-derived acetyl-CoA, an allosteric activator of pyruvate carboxylase). Weight loss with diet or bariatric surgery effectively treats NAFLD, but drugs specifically approved for NAFLD are not available. Some new pharmacological strategies act broadly to alter energy balance or influence pathways that contribute to NAFLD (e.g., agonists for PPAR γ, PPAR α/δ, FXR and analogs for FGF-21, and GLP-1). Others specifically inhibit key enzymes involved in lipid synthesis (e.g., mitochondrial pyruvate carrier, acetyl-CoA carboxylase, stearoyl-CoA desaturase, and monoacyl- and diacyl-glycerol transferases). Finally, a novel class of liver-targeted mitochondrial uncoupling agents increases hepatocellular energy expenditure, reversing the metabolic and hepatic complications of NAFLD.
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Affiliation(s)
- Varman T Samuel
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Veterans Affairs Medical Center, West Haven, CT 06516, USA.
| | - Gerald I Shulman
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA.
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81
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Abstract
Leptin is an adipocyte-derived hormone, which contributes to the homeostatic regulation of energy balance and metabolism through humoral and neural pathways. Leptin acts on the neurons in certain brain areas such as the hypothalamus, hippocampus, and brain stem to regulate food intake, thermogenesis, energy expenditure, and homeostasis of glucose/lipid metabolism. The pathologically increased circulating leptin is a biomarker of leptin resistance, which is common in obese individuals. Leptin resistance is defined by a reduced sensitivity or a failure in response of the brain to leptin, showing a decrease in the ability of leptin to suppress appetite or enhance energy expenditure, which causes an increased food intake and finally leads to overweight, obesity, cardiovascular diseases, and other metabolic disorders. Leptin resistance is a challenge for clinical treatment or drug discovery of obesity. Until recently, emerging evidence has been showing novel mechanisms of the leptin resistance. Here, we summarized the advances and controversy of leptin resistance and associated diseases, for better understanding the physiology and pathophysiology of leptin as well as the new strategies for treating obesity and metabolic disorders.
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82
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Mechanick JI, Zhao S, Garvey WT. Leptin, An Adipokine With Central Importance in the Global Obesity Problem. Glob Heart 2017; 13:113-127. [PMID: 29248361 DOI: 10.1016/j.gheart.2017.10.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 10/25/2017] [Indexed: 02/08/2023] Open
Abstract
Leptin has central importance in the global obesity and cardiovascular disease problem. Leptin is principally secreted by adipocytes and acts in the hypothalamus to suppress appetite and food intake, increase energy expenditure, and regulate body weight. Based on clinical translation of specific and networked actions, leptin affects the cardiovascular system and may be a marker and driver of cardiometabolic risk factors with interventions that are actionable by cardiologists. Leptin subnetwork analysis demonstrates a statistically significant role for ethnoculturally and socioeconomically appropriate lifestyle intervention in cardiovascular disease. Emergent mechanistic components and potential diagnostic or therapeutic targets include hexokinase 3, urocortins, clusterin, sialic acid-binding immunoglobulin-like lectin 6, C-reactive protein, platelet glycoprotein VI, albumin, pentraxin 3, ghrelin, obestatin prepropeptide, leptin receptor, neuropeptide Y, and corticotropin-releasing factor receptor 1. Emergent associated symptoms include weight change, eating disorders, vascular necrosis, chronic fatigue, and chest pain. Leptin-targeted therapies are reported for lipodystrophy and leptin deficiency, but they are investigational for leptin resistance, obesity, and other chronic diseases.
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Affiliation(s)
- Jeffrey I Mechanick
- Division of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Division of Endocrinology, Diabetes, and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Shan Zhao
- Basepaws Inc., Redondo Beach, CA, USA
| | - W Timothy Garvey
- Department of Nutritional Sciences and Diabetes Research Center, University of Alabama at Birmingham, Birmingham, AL, USA; Geriatric Research Education and Clinical Center, Birmingham Veterans Affairs Medical Center, Birmingham, AL, USA
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83
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Leptin reverses hyperglycemia and hyperphagia in insulin deficient diabetic rats by pituitary-independent central nervous system actions. PLoS One 2017; 12:e0184805. [PMID: 29190687 PMCID: PMC5708697 DOI: 10.1371/journal.pone.0184805] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 08/31/2017] [Indexed: 12/12/2022] Open
Abstract
The hypothalamic-pituitary-adrenal (HPA) axis has been postulated to play a major role in mediating the antidiabetic effects of leptin. We tested if the pituitary is essential for the chronic central nervous system mediated actions of leptin on metabolic and cardiovascular function in insulin-dependent diabetic and non-diabetic rats. Male 12-week-old hypophysectomized Sprague-Dawley rats (Hypo, n = 5) were instrumented with telemetry probes for determination of mean arterial pressure (MAP) and heart rate (HR) 24-hrs/day and an intracerebroventricular (ICV) cannula was placed into the brain lateral ventricle for continuous leptin infusion. In additional groups of Hypo and control rats (n = 5/group), diabetes was induced by single injection of streptozotocin (50 mg/kg, IP). Hypo rats were lighter, had lower MAP and HR (83±4 and 317±2 vs 105±4 mmHg and 339±4 bpm), with similar caloric intake per kilogram of body weight and fasting plasma glucose levels (84±4 vs 80±4 mg/dl) compared to controls. Chronic ICV leptin infusion (7 days, 0.62 μg/hr) in non-diabetic rats reduced caloric intake and body weight (-10%) in Hypo and control rats and markedly increased HR in control rats (~25 bpm) while causing only modest HR increases in Hypo rats (8 bpm). In diabetic Hypo and control rats, leptin infusion reduced caloric intake, body weight and glucose levels (323±74 to 99±20 and 374±27 to 108±10 mg/dl), respectively; however, the effects of leptin on HR were abolished in Hypo rats. These results indicate that hypophysectomy attenuates leptin’s effect on HR regulation without altering leptin’s ability to suppress appetite or normalize glucose levels in diabetes.
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84
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Non-invasive assessment of hepatic mitochondrial metabolism by positional isotopomer NMR tracer analysis (PINTA). Nat Commun 2017; 8:798. [PMID: 28986525 PMCID: PMC5630596 DOI: 10.1038/s41467-017-01143-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 08/22/2017] [Indexed: 01/03/2023] Open
Abstract
Hepatic mitochondria play a central role in the regulation of intermediary metabolism and maintenance of normoglycemia, and there is great interest in assessing rates of hepatic mitochondrial citrate synthase flux (VCS) and pyruvate carboxylase flux (VPC) in vivo. Here, we show that a positional isotopomer NMR tracer analysis (PINTA) method can be used to non-invasively assess rates of VCS and VPC fluxes using a combined NMR/gas chromatography-mass spectrometry analysis of plasma following infusion of [3-13C]lactate and glucose tracer. PINTA measures VCS and VPC fluxes over a wide range of physiological conditions with minimal pyruvate cycling and detects increased hepatic VCS following treatment with a liver-targeted mitochondrial uncoupler. Finally, validation studies in humans demonstrate that the VPC/VCS ratio measured by PINTA is similar to that determined by in vivo NMR spectroscopy. This method will provide investigators with a relatively simple tool to non-invasively examine the role of altered hepatic mitochondrial metabolism. Liver mitochondrial metabolism plays an important role for glucose and lipid homeostasis and its alterations contribute to metabolic disorders, including fatty liver and diabetes. Here Perry et al. develop a method for the measurement of hepatic fluxes by using lactate and glucose tracers in combination with NMR spectroscopy.
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85
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Follin C, Fjalldal S, Svärd D, van Westen D, Gabery S, Petersén Å, Lätt J, Rylander L, Erfurth EM. Microstructure alterations in the hypothalamus in cranially radiated childhood leukaemia survivors but not in craniopharyngioma patients unaffected by hypothalamic damage. Clin Endocrinol (Oxf) 2017; 87:359-366. [PMID: 28502079 DOI: 10.1111/cen.13373] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/25/2017] [Accepted: 05/09/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Metabolic complications are frequent in childhood leukaemia (ALL) survivors treated with cranial radiotherapy (CRT). These complications are potentially mediated by damage to the hypothalamus (HT), as childhood onset (CO) craniopharyngioma (CP) survivors without HT involvement are spared overt obesity. Diffusion tensor imaging (DTI) shows brain tissue microstructure alterations, by fractional anisotrophy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). We used DTI to determine the integrity of the microstructure of the HT in ALL survivors. DESIGN Case-control study. PATIENTS Three groups were included: (i) 27 CRT treated ALL survivors on hormone supplementation, (ii) 17 CO-CP survivors on hormone supplementation but without HT involvement and (iii) 27 matched controls. MEASUREMENTS DTI parameters of the HT were measured and body composition. RESULTS Microstructural alterations in the HT were more severe in ALL survivors with a BMI ≥25 than with BMI <25. Compared to controls, ALL survivors had reduced FA (P=.04), increased MD (P<.001), AD (P<.001) and RD (P<.001) in the right and left HT. In the right HT, ALL survivors with a BMI ≥25 showed elevated MD (P=.03) and AD (P=.02) compared to ALL survivors with BMI <25. In contrast, DTI parameters did not differ between CP survivors and controls. CONCLUSIONS Long-term follow-up after CRT for ALL DTI measures were affected in the HT despite complete hormone replacement. The present data suggest that ALL survivors have demyelination and axonal loss in the HT.
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Affiliation(s)
- Cecilia Follin
- Department of Endocrinology, Skåne University Hospital, Lund, Sweden
| | - Sigridur Fjalldal
- Department of Endocrinology, Skåne University Hospital, Lund, Sweden
| | - Daniel Svärd
- Clinical Sciences Lund, Diagnostic Radiology, Lund University, Lund, Sweden
- Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - Danielle van Westen
- Clinical Sciences Lund, Diagnostic Radiology, Lund University, Lund, Sweden
- Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - Sanaz Gabery
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Åsa Petersén
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Jimmy Lätt
- Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - Lars Rylander
- Division of Occupational and Environmental Medicine, Lund University, Lund, Sweden
| | - Eva Marie Erfurth
- Department of Endocrinology, Skåne University Hospital, Lund, Sweden
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86
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Abstract
A hypercaloric diet combined with a sedentary lifestyle is a major risk factor for the development of insulin resistance, type 2 diabetes mellitus (T2DM) and associated comorbidities. Standard treatment for T2DM begins with lifestyle modification, and includes oral medications and insulin therapy to compensate for progressive β-cell failure. However, current pharmaceutical options for T2DM are limited in that they do not maintain stable, durable glucose control without the need for treatment intensification. Furthermore, each medication is associated with adverse effects, which range from hypoglycaemia to weight gain or bone loss. Unexpectedly, fibroblast growth factor 1 (FGF1) and its low mitogenic variants have emerged as potentially safe candidates for restoring euglycaemia, without causing overt adverse effects. In particular, a single peripheral injection of FGF1 can lower glucose to normal levels within hours, without the risk of hypoglycaemia. Similarly, a single intracerebroventricular injection of FGF1 can induce long-lasting remission of the diabetic phenotype. This Review discusses potential mechanisms by which centrally administered FGF1 improves central glucose-sensing and peripheral glucose uptake in a sustained manner. Specifically, we explore the potential crosstalk between FGF1 and glucose-sensing neuronal circuits, hypothalamic neural stem cells and synaptic plasticity. Finally, we highlight therapeutic considerations of FGF1 and compare its metabolic actions with FGF15 (rodents), FGF19 (humans) and FGF21.
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Affiliation(s)
- Emanuel Gasser
- Gene Expression Laboratory, Salk Institute for Biological Studies
| | - Christopher P Moutos
- Gene Expression Laboratory, Salk Institute for Biological Studies
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
- College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, Arkansas 72205, USA
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
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87
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Abstract
The liver is crucial for the maintenance of normal glucose homeostasis - it produces glucose during fasting and stores glucose postprandially. However, these hepatic processes are dysregulated in type 1 and type 2 diabetes mellitus, and this imbalance contributes to hyperglycaemia in the fasted and postprandial states. Net hepatic glucose production is the summation of glucose fluxes from gluconeogenesis, glycogenolysis, glycogen synthesis, glycolysis and other pathways. In this Review, we discuss the in vivo regulation of these hepatic glucose fluxes. In particular, we highlight the importance of indirect (extrahepatic) control of hepatic gluconeogenesis and direct (hepatic) control of hepatic glycogen metabolism. We also propose a mechanism for the progression of subclinical hepatic insulin resistance to overt fasting hyperglycaemia in type 2 diabetes mellitus. Insights into the control of hepatic gluconeogenesis by metformin and insulin and into the role of lipid-induced hepatic insulin resistance in modifying gluconeogenic and net hepatic glycogen synthetic flux are also discussed. Finally, we consider the therapeutic potential of strategies that target hepatosteatosis, hyperglucagonaemia and adipose lipolysis.
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Affiliation(s)
- Max C Petersen
- Department of Internal Medicine, Yale School of Medicine
- Department of Cellular &Molecular Physiology, Yale School of Medicine
| | | | - Gerald I Shulman
- Department of Internal Medicine, Yale School of Medicine
- Department of Cellular &Molecular Physiology, Yale School of Medicine
- Howard Hughes Medical Institute, Yale School of Medicine, New Haven, Connecticut 06520, USA
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88
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Zuccoli GS, Saia-Cereda VM, Nascimento JM, Martins-de-Souza D. The Energy Metabolism Dysfunction in Psychiatric Disorders Postmortem Brains: Focus on Proteomic Evidence. Front Neurosci 2017; 11:493. [PMID: 28936160 PMCID: PMC5594406 DOI: 10.3389/fnins.2017.00493] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 08/22/2017] [Indexed: 12/27/2022] Open
Abstract
Psychiatric disorders represent a great medical and social challenge and people suffering from these conditions face many impairments regarding personal and professional life. In addition, a mental disorder will manifest itself in approximately one quarter of the world's population at some period of their life. Dysfunction in energy metabolism is one of the most consistent scientific findings associated with these disorders. With this is mind, this review compiled data on disturbances in energy metabolism found by proteomic analyses of postmortem brains collected from patients affected by the most prevalent psychiatric disorders: schizophrenia (SCZ), bipolar disorder (BPD), and major depressive disorder (MDD). We searched in the PubMed database to gather the studies and compiled all the differentially expressed proteins reported in each work. SCZ studies revealed 92 differentially expressed proteins related to energy metabolism, while 95 proteins were discovered in BPD, and 41 proteins in MDD. With the compiled data, it was possible to determine which proteins related to energy metabolism were found to be altered in all the disorders as well as which ones were altered exclusively in one of them. In conclusion, the information gathered in this work could contribute to a better understanding of the impaired metabolic mechanisms and hopefully bring insights into the underlying neuropathology of psychiatric disorders.
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Affiliation(s)
- Giuliana S Zuccoli
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of CampinasCampinas, Brazil.,Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION), Conselho Nacional de Desenvolvimento Cientifico e TecnologicoSão Paulo, Brazil
| | - Verônica M Saia-Cereda
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of CampinasCampinas, Brazil.,Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION), Conselho Nacional de Desenvolvimento Cientifico e TecnologicoSão Paulo, Brazil
| | - Juliana M Nascimento
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of CampinasCampinas, Brazil.,Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION), Conselho Nacional de Desenvolvimento Cientifico e TecnologicoSão Paulo, Brazil
| | - Daniel Martins-de-Souza
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of CampinasCampinas, Brazil.,Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION), Conselho Nacional de Desenvolvimento Cientifico e TecnologicoSão Paulo, Brazil
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89
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Neumann UH, Ho JSS, Chen S, Tam YYC, Cullis PR, Kieffer TJ. Lipid nanoparticle delivery of glucagon receptor siRNA improves glucose homeostasis in mouse models of diabetes. Mol Metab 2017; 6:1161-1172. [PMID: 29031717 PMCID: PMC5641600 DOI: 10.1016/j.molmet.2017.06.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/17/2017] [Accepted: 06/19/2017] [Indexed: 12/15/2022] Open
Abstract
Objective Hyperglucagonemia is present in many forms of diabetes and contributes to hyperglycemia, and glucagon suppression can ameliorate diabetes in mice. Leptin, a glucagon suppressor, can also reverse diabetes in rodents. Lipid nanoparticle (LNP) delivery of small interfering RNA (siRNA) effectively targets the liver and is in clinical trials for the treatment of various diseases. We compared the effectiveness of glucagon receptor (Gcgr)-siRNA delivered via LNPs to leptin in two mouse models of diabetes. Methods Gcgr siRNA encapsulated into LNPs or leptin was administered to mice with diabetes due to injection of the β-cell toxin streptozotocin (STZ) alone or combined with high fat diet (HFD/STZ). Results In STZ-diabetic mice, a single injection of Gcgr siRNA lowered blood glucose levels for 3 weeks, improved glucose tolerance, and normalized plasma ketones levels, while leptin therapy normalized blood glucose levels, oral glucose tolerance, and plasma ketones, and suppressed lipid metabolism. In contrast, in HFD/STZ-diabetic mice, Gcgr siRNA lowered blood glucose levels for 2 months, improved oral glucose tolerance, and reduced HbA1c, while leptin had no beneficial effects. Conclusions While leptin may be more effective than Gcgr siRNA at normalizing both glucose and lipid metabolism in STZ diabetes, Gcgr siRNA is more effective at reducing blood glucose levels in HFD/STZ diabetes. Gcgr siRNA improves glucose metabolism but not lipid metabolism in STZ diabetic mice. Leptin improves both glucose and lipid metabolism in STZ diabetic mice. Gcgr siRNA improves glucose metabolism in HFD/STZ diabetic mice. Leptin does not improve glucose metabolism in HFD/STZ diabetic mice.
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Affiliation(s)
- Ursula H Neumann
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Jessica S S Ho
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Sam Chen
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Yuen Yi C Tam
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Pieter R Cullis
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
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90
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Xiang L, Li J, Wang Q, Tang R, Qi J. Leptin Gene Transfer Improves Symptoms of Type 2 Diabetic Mice by Regulating Leptin Signaling Pathway and Insulin Resistance of Peripheral Tissues. Hum Gene Ther 2017. [PMID: 28622065 DOI: 10.1089/hum.2016.174] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The leptin gene was transferred into the liver of streptozocin- and high fat diet-induced type 2 diabetic (T2D) mice by hydrodynamic-based gene delivery. The food intake, water consumption, glucose concentration, and triglyceride and total cholesterol levels of T2D mice were significantly decreased. Meanwhile, plasma leptin was remarkably increased after gene transfer for 2, 3, 5, and 7 days, while plasma adiponectin was also significantly increased at day 2. To understand the mechanism of action of leptin on T2D mice, gene expressions related to glycometabolism and energy metabolism in the liver, epididymal adipose tissue, hypothalamus, and muscle were measured. The mRNA expression levels of adiponectin receptor 1 (ADR1), glucose transporter 4 (GLUT4), glucose-6-phosphase, and peroxisome proliferator-activated receptor γ in the liver, leptin, adiponectin, and hormone-sensitive lipase in adipose tissue, leptin, leptin-receptor, ADR1 in the hypothalamus, and ADR1, GLUT4, and insulin 1 in the gastrocnemius significantly increased. Moreover, the hepatic glycogen of the leptin-gene-treated group was significantly increased in comparison to the control group. Meanwhile, the significant decrease of forkhead box O1, adiponectin receptor 2, and peroxisome proliferator-activated receptor α in the liver, and agouti-related protein and proopiomelanocortin genes in the hypothalamus were also observed. In fat tissue and hypothalamus, leptin and adiponectin protein levels were also significantly increased, whereas the neuropeptide Y protein level was significantly decreased. These results indicated that the leptin gene transfer could improve the symptoms of T2D mice by regulating the leptin-hypothalamus signaling pathway and improving the insulin resistance of the peripheral tissues of T2D mice.
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Affiliation(s)
- Lan Xiang
- College of Pharmaceutical Sciences, Zhejiang University , Hangzhou, China
| | - Jing Li
- College of Pharmaceutical Sciences, Zhejiang University , Hangzhou, China
| | - Qian Wang
- College of Pharmaceutical Sciences, Zhejiang University , Hangzhou, China
| | - Ruiqi Tang
- College of Pharmaceutical Sciences, Zhejiang University , Hangzhou, China
| | - Jianhua Qi
- College of Pharmaceutical Sciences, Zhejiang University , Hangzhou, China
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91
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D'souza AM, Neumann UH, Glavas MM, Kieffer TJ. The glucoregulatory actions of leptin. Mol Metab 2017; 6:1052-1065. [PMID: 28951828 PMCID: PMC5605734 DOI: 10.1016/j.molmet.2017.04.011] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/18/2017] [Accepted: 04/24/2017] [Indexed: 12/28/2022] Open
Abstract
Background The hormone leptin is an important regulator of metabolic homeostasis, able to inhibit food intake and increase energy expenditure. Leptin can also independently lower blood glucose levels, particularly in hyperglycemic models of leptin or insulin deficiency. Despite significant efforts and relevance to diabetes, the mechanisms by which leptin acts to regulate blood glucose levels are not fully understood. Scope of review Here we assess literature relevant to the glucose lowering effects of leptin. Leptin receptors are widely expressed in multiple cell types, and we describe both peripheral and central effects of leptin that may be involved in lowering blood glucose. In addition, we summarize the potential clinical application of leptin in regulating glucose homeostasis. Major conclusions Leptin exerts a plethora of metabolic effects on various tissues including suppressing production of glucagon and corticosterone, increasing glucose uptake, and inhibiting hepatic glucose output. A more in-depth understanding of the mechanisms of the glucose-lowering actions of leptin may reveal new strategies to treat metabolic disorders.
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Affiliation(s)
- Anna M D'souza
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Ursula H Neumann
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Maria M Glavas
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.,Department of Surgery, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
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92
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da Silva AA, Hall JE, Moak SP, Browning J, Houghton HJ, Micheloni GC, do Carmo JM. Role of autonomic nervous system in chronic CNS-mediated antidiabetic action of leptin. Am J Physiol Endocrinol Metab 2017; 312:E420-E428. [PMID: 27923809 PMCID: PMC5451526 DOI: 10.1152/ajpendo.00301.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 01/13/2023]
Abstract
This study tested whether ganglionic blockade or hepatic vagotomy attenuates the chronic central nervous system (CNS)-mediated antidiabetic and cardiovascular effects of leptin. Male Sprague-Dawley rats were instrumented with telemetry probes and arterial and venous catheters for determination of blood pressure (BP), heart rate (HR), blood sampling, and intravenous (iv) infusions. An intracerebroventricular (ICV) cannula was placed into the brain lateral ventricle for infusion of leptin or vehicle. After control measurements, streptozotocin (STZ) was injected iv (50 mg/kg) to induce diabetes, and 5 days later leptin (n = 6) or saline vehicle (n = 5) was infused ICV for 12 days via osmotic pumps. Beginning on day 6 of leptin treatment, the ganglionic blocker hexamethonium (15 mg·kg-1·day-1 iv) was infused, while leptin infusion was continued, to assess the role of the autonomic nervous system. Induction of diabetes was associated with increases in blood glucose (98 ± 7 to 350 ± 19 mg/dl), food intake (23 ± 3 to 43 ± 3 g/day), decreases in HR (-70 ± 11 beats/min), polyuria, and increased water consumption, which were all completely normalized by ICV leptin infusion. Although hexamethonium attenuated leptin's effect on HR, it failed to impair leptin's ability to restore euglycemia or to prevent the polyuria or increased water intake in STZ-diabetic rats. We also found that after pretreatment with hexamethonium (n = 8), ICV leptin infusion, during continued ganglionic blockade, completely normalized blood glucose in diabetic rats. In addition, selective hepatic vagotomy did not attenuate leptin's ability to restore euglycemia in diabetic rats. These results suggest that leptin's powerful chronic CNS antidiabetic actions are mediated primarily via nonautonomic mechanisms.
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Affiliation(s)
- Alexandre A da Silva
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi; and
- Barão de Mauá University Center, Ribeirão Preto, São Paulo, Brazil
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Sydney P Moak
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Jackson Browning
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Haley J Houghton
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi; and
| | | | - Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi; and
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93
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Sharabi K, Lin H, Tavares CDJ, Dominy JE, Camporez JP, Perry RJ, Schilling R, Rines AK, Lee J, Hickey M, Bennion M, Palmer M, Nag PP, Bittker JA, Perez J, Jedrychowski MP, Ozcan U, Gygi SP, Kamenecka TM, Shulman GI, Schreiber SL, Griffin PR, Puigserver P. Selective Chemical Inhibition of PGC-1α Gluconeogenic Activity Ameliorates Type 2 Diabetes. Cell 2017; 169:148-160.e15. [PMID: 28340340 PMCID: PMC5398763 DOI: 10.1016/j.cell.2017.03.001] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 12/22/2016] [Accepted: 02/27/2017] [Indexed: 01/27/2023]
Abstract
Type 2 diabetes (T2D) is a worldwide epidemic with a medical need for additional targeted therapies. Suppression of hepatic glucose production (HGP) effectively ameliorates diabetes and can be exploited for its treatment. We hypothesized that targeting PGC-1α acetylation in the liver, a chemical modification known to inhibit hepatic gluconeogenesis, could be potentially used for treatment of T2D. Thus, we designed a high-throughput chemical screen platform to quantify PGC-1α acetylation in cells and identified small molecules that increase PGC-1α acetylation, suppress gluconeogenic gene expression, and reduce glucose production in hepatocytes. On the basis of potency and bioavailability, we selected a small molecule, SR-18292, that reduces blood glucose, strongly increases hepatic insulin sensitivity, and improves glucose homeostasis in dietary and genetic mouse models of T2D. These studies have important implications for understanding the regulatory mechanisms of glucose metabolism and treatment of T2D.
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Affiliation(s)
- Kfir Sharabi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Hua Lin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Clint D J Tavares
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - John E Dominy
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Joao Paulo Camporez
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Roger Schilling
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Amy K Rines
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Jaemin Lee
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Marc Hickey
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Melissa Bennion
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Michelle Palmer
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Partha P Nag
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - José Perez
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Umut Ozcan
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Steve P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Theodore M Kamenecka
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| | | | - Patrick R Griffin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Pere Puigserver
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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94
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Perry RJ, Peng L, Cline GW, Petersen KF, Shulman GI. A Non-invasive Method to Assess Hepatic Acetyl-CoA In Vivo. Cell Metab 2017; 25:749-756. [PMID: 28111213 PMCID: PMC5342911 DOI: 10.1016/j.cmet.2016.12.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/29/2016] [Accepted: 12/22/2016] [Indexed: 01/31/2023]
Abstract
Acetyl-coenzyme A (acetyl-CoA) is a critical metabolic signaling molecule that regulates gluconeogenesis, pyruvate oxidation, protein acetylation, and steroid and fatty acid biosynthesis; however, measurements of this metabolite using standard biochemical approaches are technically demanding, and there is currently no method to non-invasively assess hepatic acetyl-CoA content in vivo. To this end, we developed and validated a method to non-invasively detect differences in hepatic acetyl-CoA content in vivo across a 5-fold range of physiological acetyl-CoA concentrations by assessing the turnover of [13C4]β-hydroxybutyrate (β-OHB). Here, we show a strong correlation (R2 = 0.86, p < 0.0001) between hepatic acetyl-CoA content and β-OHB turnover in rats with varying degrees of fasting hyperglycemia and insulin resistance. These studies demonstrate that β-OHB turnover can be used as a surrogate to non-invasively assess hepatic acetyl-CoA content, thereby allowing researchers to further elucidate the role of this metabolite in the regulation of hepatic gluconeogenesis and other metabolic processes in vivo.
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Affiliation(s)
- Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Liang Peng
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Gary W Cline
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Kitt Falk Petersen
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA.
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95
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Corbit KC, Camporez JPG, Tran JL, Wilson CG, Lowe DA, Nordstrom SM, Ganeshan K, Perry RJ, Shulman GI, Jurczak MJ, Weiss EJ. Adipocyte JAK2 mediates growth hormone-induced hepatic insulin resistance. JCI Insight 2017; 2:e91001. [PMID: 28194444 DOI: 10.1172/jci.insight.91001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
For nearly 100 years, growth hormone (GH) has been known to affect insulin sensitivity and risk of diabetes. However, the tissue governing the effects of GH signaling on insulin and glucose homeostasis remains unknown. Excess GH reduces fat mass and insulin sensitivity. Conversely, GH insensitivity (GHI) is associated with increased adiposity, augmented insulin sensitivity, and protection from diabetes. Here, we induce adipocyte-specific GHI through conditional deletion of Jak2 (JAK2A), an obligate transducer of GH signaling. Similar to whole-body GHI, JAK2A mice had increased adiposity and extreme insulin sensitivity. Loss of adipocyte Jak2 augmented hepatic insulin sensitivity and conferred resistance to diet-induced metabolic stress without overt changes in circulating fatty acids. While GH injections induced hepatic insulin resistance in control mice, the diabetogenic action was absent in JAK2A mice. Adipocyte GH signaling directly impinged on both adipose and hepatic insulin signal transduction. Collectively, our results show that adipose tissue governs the effects of GH on insulin and glucose homeostasis. Further, we show that JAK2 mediates liver insulin sensitivity via an extrahepatic, adipose tissue-dependent mechanism.
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Affiliation(s)
- Kevin C Corbit
- Cardiovascular Research Institute, UCSF, San Francisco, California, USA
| | | | - Jennifer L Tran
- Cardiovascular Research Institute, UCSF, San Francisco, California, USA
| | - Camella G Wilson
- Cardiovascular Research Institute, UCSF, San Francisco, California, USA
| | - Dylan A Lowe
- Cardiovascular Research Institute, UCSF, San Francisco, California, USA
| | - Sarah M Nordstrom
- Cardiovascular Research Institute, UCSF, San Francisco, California, USA
| | - Kirthana Ganeshan
- Cardiovascular Research Institute, UCSF, San Francisco, California, USA
| | | | - Gerald I Shulman
- Department of Internal Medicine.,Cellular and Molecular Physiology, and.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Michael J Jurczak
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ethan J Weiss
- Cardiovascular Research Institute, UCSF, San Francisco, California, USA
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96
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Mueller KM, Hartmann K, Kaltenecker D, Vettorazzi S, Bauer M, Mauser L, Amann S, Jall S, Fischer K, Esterbauer H, Müller TD, Tschöp MH, Magnes C, Haybaeck J, Scherer T, Bordag N, Tuckermann JP, Moriggl R. Adipocyte Glucocorticoid Receptor Deficiency Attenuates Aging- and HFD-Induced Obesity and Impairs the Feeding-Fasting Transition. Diabetes 2017; 66:272-286. [PMID: 27650854 DOI: 10.2337/db16-0381] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 09/14/2016] [Indexed: 11/13/2022]
Abstract
Glucocorticoids (GCs) are important regulators of systemic energy metabolism, and aberrant GC action is linked to metabolic dysfunctions. Yet, the extent to which normal and pathophysiological energy metabolism depend on the GC receptor (GR) in adipocytes remains unclear. Here, we demonstrate that adipocyte GR deficiency in mice significantly impacts systemic metabolism in different energetic states. Plasma metabolomics and biochemical analyses revealed a marked global effect of GR deficiency on systemic metabolite abundance and, thus, substrate partitioning in fed and fasted states. This correlated with a decreased lipolytic capacity of GR-deficient adipocytes under postabsorptive and fasting conditions, resulting from impaired signal transduction from β-adrenergic receptors to adenylate cyclase. Upon prolonged fasting, the impaired lipolytic response resulted in abnormal substrate utilization and lean mass wasting. Conversely, GR deficiency attenuated aging-/diet-associated obesity, adipocyte hypertrophy, and liver steatosis. Systemic glucose tolerance was improved in obese GR-deficient mice, which was associated with increased insulin signaling in muscle and adipose tissue. We conclude that the GR in adipocytes exerts central but diverging roles in the regulation of metabolic homeostasis depending on the energetic state. The adipocyte GR is indispensable for the feeding-fasting transition but also promotes adiposity and associated metabolic disorders in fat-fed and aged mice.
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Affiliation(s)
- Kristina M Mueller
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
| | - Kerstin Hartmann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | | | - Sabine Vettorazzi
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Mandy Bauer
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Lea Mauser
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Sabine Amann
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Sigrid Jall
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Katrin Fischer
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Harald Esterbauer
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Christoph Magnes
- HEALTH Institute for Biomedicine and Health Sciences, JOANNEUM RESEARCH, Forschungsgesellschaft mbH, Graz, Austria
| | | | - Thomas Scherer
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Natalie Bordag
- Center for Biomarker Research in Medicine, CBmed GmbH, Graz, Austria
| | - Jan P Tuckermann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Richard Moriggl
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Medical University of Vienna, Vienna, Austria
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97
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Kaltenecker D, Mueller KM, Benedikt P, Feiler U, Themanns M, Schlederer M, Kenner L, Schweiger M, Haemmerle G, Moriggl R. Adipocyte STAT5 deficiency promotes adiposity and impairs lipid mobilisation in mice. Diabetologia 2017; 60:296-305. [PMID: 27858140 PMCID: PMC6518368 DOI: 10.1007/s00125-016-4152-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/12/2016] [Indexed: 01/04/2023]
Abstract
AIMS/HYPOTHESIS Dysfunction of lipid metabolism in white adipose tissue can substantially interfere with health and quality of life, for example in obesity and associated metabolic diseases. Therefore, it is important to characterise pathways that regulate lipid handling in adipocytes and determine how they affect metabolic homeostasis. Components of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway are involved in adipocyte physiology and pathophysiology. However, the exact physiological importance of the STAT family member STAT5 in white adipose tissue is yet to be determined. Here, we aimed to delineate adipocyte STAT5 functions in the context of lipid metabolism in white adipose tissue. METHODS We generated an adipocyte specific knockout of Stat5 in mice using the Adipoq-Cre recombinase transgene followed by in vivo and in vitro biochemical and molecular studies. RESULTS Adipocyte-specific deletion of Stat5 resulted in increased adiposity, while insulin resistance and gluconeogenic capacity was decreased, indicating that glucose metabolism can be improved by interfering with adipose STAT5 function. Basal lipolysis and fasting-induced lipid mobilisation were diminished upon STAT5 deficiency, which coincided with reduced levels of the rate-limiting lipase of triacylglycerol hydrolysis, adipose triglyceride lipase (ATGL, encoded by Pnpla2) and its coactivator comparative gene identification 58 (CGI-58). In a mechanistic analysis, we identified a functional STAT5 response element within the Pnpla2 promoter, indicating that Pnpla2 is transcriptionally regulated by STAT5. CONCLUSIONS/INTERPRETATION Our findings reveal an essential role for STAT5 in maintaining lipid homeostasis in white adipose tissue and provide a rationale for future studies into the potential of STAT5 manipulation to improve outcomes in metabolic diseases.
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Affiliation(s)
- Doris Kaltenecker
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Kristina M Mueller
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Pia Benedikt
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ursula Feiler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Madeleine Themanns
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Michaela Schlederer
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Lukas Kenner
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
- Unit of Pathology of Laboratory Animals, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Richard Moriggl
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria.
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
- Medical University of Vienna, Vienna, Austria.
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98
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Oberlin D, Buettner C. How does leptin restore euglycemia in insulin-deficient diabetes? J Clin Invest 2017; 127:450-453. [PMID: 28112680 DOI: 10.1172/jci91880] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Insulin replacement is the cornerstone of type 1 diabetes (T1D) treatment; however, glycemic control remains a challenge. Leptin has been shown to effectively restore euglycemia in rodent models of T1D; however, the mechanism or mechanisms by which leptin exerts glycemic control are unclear. In this issue of the JCI, Perry and colleagues provide evidence that suppression of lipolysis is a key facet of leptin-mediated restoration of euglycemia. However, more work remains to be done to fully understand the antidiabetic mechanisms of leptin.
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99
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Perry RJ, Peng L, Abulizi A, Kennedy L, Cline GW, Shulman GI. Mechanism for leptin's acute insulin-independent effect to reverse diabetic ketoacidosis. J Clin Invest 2017; 127:657-669. [PMID: 28112679 DOI: 10.1172/jci88477] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 10/27/2016] [Indexed: 01/10/2023] Open
Abstract
The mechanism by which leptin reverses diabetic ketoacidosis (DKA) is unknown. We examined the acute insulin-independent effects of leptin replacement therapy in a streptozotocin-induced rat model of DKA. Leptin infusion reduced rates of lipolysis, hepatic glucose production (HGP), and hepatic ketogenesis by 50% within 6 hours and were independent of any changes in plasma glucagon concentrations; these effects were abrogated by coinfusion of corticosterone. Treating leptin- and corticosterone-infused rats with an adipose triglyceride lipase inhibitor blocked corticosterone-induced increases in plasma glucose concentrations and rates of HGP and ketogenesis. Similarly, adrenalectomized type 1 diabetic (T1D) rats exhibited decreased rates of lipolysis, HGP, and ketogenesis; these effects were reversed by corticosterone infusion. Leptin-induced decreases in lipolysis, HGP, and ketogenesis in DKA were also nullified by relatively small increases (15 to 70 pM) in plasma insulin concentrations. In contrast, the chronic glucose-lowering effect of leptin in a STZ-induced mouse model of poorly controlled T1D was associated with decreased food intake, reduced plasma glucagon and corticosterone concentrations, and decreased ectopic lipid (triacylglycerol/diacylglycerol) content in liver and muscle. Collectively, these studies demonstrate marked differences in the acute insulin-independent effects by which leptin reverses fasting hyperglycemia and ketoacidosis in a rodent model of DKA versus the chronic pleotropic effects by which leptin reverses hyperglycemia in a non-DKA rodent model of T1D.
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100
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Minokoshi Y. Hypothalamic control of glucose and lipid metabolism in skeletal muscle. ACTA ACUST UNITED AC 2017. [DOI: 10.7600/jpfsm.6.75] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Yasuhiko Minokoshi
- Division of Endocrinology and Metabolism, Department of Homeostatic Regulation, National Institute for Physiological Sciences
- Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (Sokendai)
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