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Estes SK, Shiota C, O'Brien TP, Printz RL, Shiota M. The impact of glucagon to support postabsorptive glucose flux and glycemia in healthy rats and its attenuation in male Zucker diabetic fatty rats. Am J Physiol Endocrinol Metab 2024; 326:E308-E325. [PMID: 38265288 PMCID: PMC11193518 DOI: 10.1152/ajpendo.00192.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 01/19/2024] [Accepted: 01/19/2024] [Indexed: 01/25/2024]
Abstract
Hyperglucagonemia is a hallmark of type 2 diabetes (T2DM), yet the role of elevated plasma glucagon (P-GCG) to promote excessive postabsorptive glucose production and contribute to hyperglycemia in patients with this disease remains debatable. We investigated the acute action of P-GCG to safeguard/support postabsorptive endogenous glucose production (EGP) and euglycemia in healthy Zucker control lean (ZCL) rats. Using male Zucker diabetic fatty (ZDF) rats that exhibit the typical metabolic disorders of human T2DM, such as excessive EGP, hyperglycemia, hyperinsulinemia, and hyperglucagonemia, we examined the ability of hyperglucagonemia to promote greater rates of postabsorptive EGP and hyperglycemia. Euglycemic or hyperglycemic basal insulin (INS-BC) and glucagon (GCG-BC) clamps were performed in the absence or during an acute setting of glucagon deficiency (GCG-DF, ∼10% of basal), either alone or in combination with insulin deficiency (INS-DF, ∼10% of basal). Glucose appearance, disappearance, and cycling rates were measured using [2-3H] and [3-3H]-glucose. In ZCL rats, GCG-DF reduced the levels of hepatic cyclic AMP, EGP, and plasma glucose (PG) by 50%, 32%, and 50%, respectively. EGP fell in the presence GCG-DF and INS-BC, but under GCG-DF and INS-DF, EGP and PG increased two- and threefold, respectively. GCG-DF revealed the hyperglucagonemia present in ZDF rats lacked the ability to regulate hepatic intracellular cyclic AMP levels and glucose flux, since EGP and PG levels fell by only 10%. We conclude that the liver in T2DM suffers from resistance to all three major regulatory factors, glucagon, insulin, and glucose, thus leading to a loss of metabolic flexibility.NEW & NOTEWORTHY In postabsorptive state, basal plasma insulin (P-INS) and plasma glucose (PG) act dominantly to increase hepatic glucose cycling and reduce endogenous glucose production (EGP) and PG in healthy rats, which is only counteracted by the acute action of basal plasma glucagon (P-GCG) to support EGP and euglycemia. Hyperglucagonemia, a hallmark of type 2 diabetes (T2DM) present in Zucker diabetic fatty (ZDF) rats, is not the primary mediator of hyperglycemia and high EGP as commonly thought; instead, the liver is resistant to glucagon as well as insulin and glucose.
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Affiliation(s)
- Shanea K Estes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Chiyo Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Tracy P O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Richard L Printz
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
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2
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Safarzad M, Jazi MS, Kiaei M, Asadi J. Lower serum zinc level is associated with higher fasting insulin in type 2 diabetes mellitus (T2DM) and relates with disturbed glucagon suppression response in male patients. Prim Care Diabetes 2023; 17:493-498. [PMID: 37391316 DOI: 10.1016/j.pcd.2023.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/29/2023] [Accepted: 05/30/2023] [Indexed: 07/02/2023]
Abstract
AIMS Zinc ion can play critical role in glycemic control in diabetes mellitus (DM), contributing to both insulin synthesis and secretion. In this study, we aimed to investigate the level of zinc in diabetic patients and its association with glycemic parameters, insulin, and glucagon level. METHODS 112 individuals (59 cases of type 2DM and 53 non-diabetic controls) were included in this study. Biochemical parameters (FBG, 2hpp, HbA1C), and zinc level in the serum were measured using colorimetric assays. Insulin and glucagon were measured by ELISA method. HOMA-IR, HOMA-B, reciprocal HOMA-B, and Quicki indices were calculated using appropriate formula. For further analysis, patients were divided into two groups: high (>135.5 μg/dl) and low (<135.5 μg/dl) zinc. Glucagon suppression was considered yes if 2hpp glucagon < fasting glucagon. RESULTS Our results showed that serum Zn level in type 2 DM patients was lower than control (P value=0.02). Patients with lower Zn had higher fasting insulin (P value=0.006) and higher β-cell activity index (HOMA-B, p value=0.02), however fasting glucagon and parameters of hyperglycemia (FBG, 2hpp, Hba1C) were not different. Moreover, insulin sensitivity and resistance indices (Quicki, HOMA-IR,1/HOMA-IR) showed non-significantly improved status in high Zn group. We found non-significant association between glucagon suppression and Zn level in both genders (N = 39, p value = 0.07), however, it was significant in males (N = 14, p value = 0.02). CONCLUSION Altogether, our results indicated reduced serum Zn in type 2DM can exacerbate hyperinsulinemia and glucagon suppression (only significant in the male), highlighting its importance in type 2DM control.
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Affiliation(s)
- Mahdieh Safarzad
- Metabolic Disorders Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Marie Saghaeian Jazi
- Metabolic Disorders Research Center, Golestan University of Medical Sciences, Gorgan, Iran; Stem Cell Research Center, Golestan University of Medical Sciences, Gorgan, Iran.
| | - Mohammadreza Kiaei
- Laboratory Sciences Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Jahanbakhsh Asadi
- Metabolic Disorders Research Center, Golestan University of Medical Sciences, Gorgan, Iran
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Capozzi ME, D'Alessio DA, Campbell JE. The past, present, and future physiology and pharmacology of glucagon. Cell Metab 2022; 34:1654-1674. [PMID: 36323234 PMCID: PMC9641554 DOI: 10.1016/j.cmet.2022.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/23/2022] [Accepted: 09/30/2022] [Indexed: 11/07/2022]
Abstract
The evolution of glucagon has seen the transition from an impurity in the preparation of insulin to the development of glucagon receptor agonists for use in type 1 diabetes. In type 2 diabetes, glucagon receptor antagonists have been explored to reduce glycemia thought to be induced by hyperglucagonemia. However, the catabolic actions of glucagon are currently being leveraged to target the rise in obesity that paralleled that of diabetes, bringing the pharmacology of glucagon full circle. During this evolution, the physiological importance of glucagon advanced beyond the control of hepatic glucose production, incorporating critical roles for glucagon to regulate both lipid and amino acid metabolism. Thus, it is unsurprising that the study of glucagon has left several paradoxes that make it difficult to distill this hormone down to a simplified action. Here, we describe the history of glucagon from the past to the present and suggest some direction to the future of this field.
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Affiliation(s)
- Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA
| | - David A D'Alessio
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27701, USA.
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Rodgers RL. Glucagon, cyclic AMP, and hepatic glucose mobilization: A half‐century of uncertainty. Physiol Rep 2022; 10:e15263. [PMID: 35569125 PMCID: PMC9107925 DOI: 10.14814/phy2.15263] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/16/2022] [Accepted: 03/18/2022] [Indexed: 12/14/2022] Open
Abstract
For at least 50 years, the prevailing view has been that the adenylate cyclase (AC)/cyclic AMP (cAMP)/protein kinase A pathway is the predominant signal mediating the hepatic glucose‐mobilizing actions of glucagon. A wealth of evidence, however, supports the alternative, that the operative signal most of the time is the phospholipase C (PLC)/inositol‐phosphate (IP3)/calcium/calmodulin pathway. The evidence can be summarized as follows: (1) The consensus threshold glucagon concentration for activating AC ex vivo is 100 pM, but the statistical hepatic portal plasma glucagon concentration range, measured by RIA, is between 28 and 60 pM; (2) Within that physiological concentration range, glucagon stimulates the PLC/IP3 pathway and robustly increases glucose output without affecting the AC/cAMP pathway; (3) Activation of a latent, amplified AC/cAMP pathway at concentrations below 60 pM is very unlikely; and (4) Activation of the PLC/IP3 pathway at physiological concentrations produces intracellular effects that are similar to those produced by activation of the AC/cAMP pathway at concentrations above 100 pM, including elevated intracellular calcium and altered activities and expressions of key enzymes involved in glycogenolysis, gluconeogenesis, and glycogen synthesis. Under metabolically stressful conditions, as in the early neonate or exercising adult, plasma glucagon concentrations often exceed 100 pM, recruiting the AC/cAMP pathway and enhancing the activation of PLC/IP3 pathway to boost glucose output, adaptively meeting the elevated systemic glucose demand. Whether the AC/cAMP pathway is consistently activated in starvation or diabetes is not clear. Because the importance of glucagon in the pathogenesis of diabetes is becoming increasingly evident, it is even more urgent now to resolve lingering uncertainties and definitively establish glucagon’s true mechanism of glycemia regulation in health and disease.
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Affiliation(s)
- Robert L. Rodgers
- Department of Biomedical and Pharmaceutical Sciences College of Pharmacy University of Rhode Island Kingston Rhode Island USA
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da Silva AA, Hall JE, Dai X, Wang Z, Salgado MC, do Carmo JM. Chronic Antidiabetic Actions of Leptin: Evidence From Parabiosis Studies for a CNS-Derived Circulating Antidiabetic Factor. Diabetes 2021; 70:2264-2274. [PMID: 34344788 PMCID: PMC8576509 DOI: 10.2337/db21-0126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 07/25/2021] [Indexed: 11/13/2022]
Abstract
We used parabiosis to determine whether the central nervous system (CNS)-mediated antidiabetic effects of leptin are mediated by release of brain-derived circulating factors. Parabiosis was surgically induced at 4 weeks of age, and an intracerebroventricular (ICV) cannula was placed in the lateral cerebral ventricle at 12 weeks of age for ICV infusion of leptin or saline vehicle. Ten days after surgery, food intake, body weight, and blood glucose were measured for 5 consecutive days, and insulin-deficiency diabetes was induced in all rats by a single streptozotocin (STZ) injection (40 mg/kg). Five days after STZ injection, leptin or vehicle was infused ICV for 7 days, followed by 5-day recovery period. STZ increased blood glucose and food intake. Chronic ICV leptin infusion restored normoglycemia in leptin-infused rats while reducing blood glucose by ∼27% in conjoined vehicle-infused rats. This glucose reduction was caused mainly by decreased hepatic gluconeogenesis. Chronic ICV leptin infusion also reduced net cumulative food intake and increased GLUT4 expression in skeletal muscle in leptin/vehicle compared with vehicle/vehicle conjoined rats. These results indicate that leptin's CNS-mediated antidiabetic effects are mediated, in part, by release into the systemic circulation of leptin-stimulated factors that enhance glucose utilization and reduce liver gluconeogenesis.
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Affiliation(s)
- Alexandre A da Silva
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS
| | - Xuemei Dai
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS
| | - Zhen Wang
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS
| | - Mateus C Salgado
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS
- Centro Universitário Barão de Mauá, Ribeirão Preto, São Paulo, Brazil
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS
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Zeigerer A, Sekar R, Kleinert M, Nason S, Habegger KM, Müller TD. Glucagon's Metabolic Action in Health and Disease. Compr Physiol 2021; 11:1759-1783. [PMID: 33792899 PMCID: PMC8513137 DOI: 10.1002/cphy.c200013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Discovered almost simultaneously with insulin, glucagon is a pleiotropic hormone with metabolic action that goes far beyond its classical role to increase blood glucose. Albeit best known for its ability to directly act on the liver to increase de novo glucose production and to inhibit glycogen breakdown, glucagon lowers body weight by decreasing food intake and by increasing metabolic rate. Glucagon further promotes lipolysis and lipid oxidation and has positive chronotropic and inotropic effects in the heart. Interestingly, recent decades have witnessed a remarkable renaissance of glucagon's biology with the acknowledgment that glucagon has pharmacological value beyond its classical use as rescue medication to treat severe hypoglycemia. In this article, we summarize the multifaceted nature of glucagon with a special focus on its hepatic action and discuss the pharmacological potential of either agonizing or antagonizing the glucagon receptor for health and disease. © 2021 American Physiological Society. Compr Physiol 11:1759-1783, 2021.
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Affiliation(s)
- Anja Zeigerer
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Revathi Sekar
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Maximilian Kleinert
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Shelly Nason
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kirk M. Habegger
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Timo D. Müller
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, Eberhard Karls University Hospitals and Clinics, Tübingen, Germany
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Cui F, Hu M, Li R, Li B, Huang D, Ma W, Jia X, Lv Z. Insulin on changes in expressions of aquaporin-1, aquaporin-5, and aquaporin-8 in submandibular salivary glands of rats with Streptozotocin-induced diabetes. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2021; 14:221-229. [PMID: 33564354 PMCID: PMC7868788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
OBJECTIVE This study aimed to explore the relationship between diabetic xerostomia and changes in aquaporin-1 (AQP1), aquaporin-5 (AQP5), and aquaporin-8 (AQP8) expression in the submandibular glands (SMGs), to further study the pathogenesis of diabetic xerostomia and to observe the therapeutic effect of insulin (INS). METHODS Thirty SD rats were randomized equally into 3 groups: control group, diabetic model (DM) group and insulin (INS) group (n=10, respectively). The control group received no treatment. DM group and INS group were induced by a high-fat diet and streptozotocin intraperitoneal injection. After establishment of a diabetic rat model, the rats in INS group were treated with insulin. Then all rats were fed continuously with ordinary diet for 2 months. H&E staining was used to describe morphologic changes in the SMGs of rats. Immunohistochemistry was used to analyze the expressions and localization of AQP1, AQP5, and AQP8 in the SMGs. Computer image analysis was used to detect the mean optical density (MOD) values of AQP1, AQP5, and AQP8 expression, and changes in the diameters of acini and ducts. RESULTS The acini were mildly atrophied and the acinar cells were rearranged in an irregular way. The morphology of insulin-administered diabetic SMGs was similar to that of the control group. The acinar average circumference and GCT average diameter in DM group were significantly reduced (P<0.05). The acinar average circumference and GCT average diameter of INS group were significantly increased (P<0.05). The expressions of AQP1, AQP5, and AQP8 were significantly reduced in DM group (P<0.05). The expressions of AQP1, AQP5, and AQP8 in INS group were significantly increased (P<0.05). CONCLUSION The decreased expressions of AQP1, AQP5, and AQP8 led to decreased salivary secretion of SMGs in diabetic rats, which may be involved in the pathogenesis of diabetic xerostomia. Insulin could up-regulate the expressions of AQP1, AQP5 and AQP8, and play a protective role in the secretory function of diabetic SMGs.
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Affiliation(s)
- Fangqin Cui
- Department of Pathophysiology, Bengbu Medical CollegeBengbu 233030, China
| | - Mingji Hu
- Department of Orthopedics, The Second People’s Hospital of BengbuBengbu 233030, China
| | - Ran Li
- Department of Pathology, The First Affiliated Hospital of Bengbu, Medical College, Bengbu Medical CollegeBengbu 233030, China
| | - Bao Li
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Dake Huang
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Wenhao Ma
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Xuemei Jia
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Zhengmei Lv
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
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Abstract
PURPOSE OF REVIEW In this brief review, we highlight studies that have contributed to our current understanding of glucose homeostasis by the central nervous system (CNS) leptin-melanocortin system, particularly proopiomelanocortin neurons and melanocortin-4 receptors (MC4R). RECENT FINDINGS Leptin deficiency is associated with insulin resistance and impaired glucose metabolism whereas leptin administration improves tissue glucose uptake/oxidation and reduces hepatic glucose output. These antidiabetic effects of leptin have been demonstrated in experimental animals and humans, even when circulating insulin levels are barely detectable. Recent evidence suggests that these antidiabetic actions of leptin are mediated, in large part, by stimulation of leptin receptors (LRs) in the CNS and require activation of proopiomelanocortin (POMC) neurons and MC4R. These chronic antidiabetic effects of the CNS leptin-melanocortin system appear to be independent of autonomic nervous system and pituitary-thyroid-adrenal (PTA) axis mechanisms. The powerful antidiabetic actions of the CNS leptin-melanocortin system are capable of normalizing plasma glucose even in the absence of insulin and involve interactions of multiple neuronal populations and intracellular signaling pathways. Although the links between the CNS leptin-melanocortin system and its chronic effects on peripheral tissue glucose metabolism are still uncertain, they are independent of insulin action, activation of the autonomic nervous system, or the PTA axis. Unraveling the pathways that contribute to the powerful antidiabetic effects of the CNS leptin-melanocortin system may provide novel therapeutic approaches for diabetes mellitus.
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Affiliation(s)
- Alexandre A da Silva
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA.
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA
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Zouhar P, Rakipovski G, Bokhari MH, Busby O, Paulsson JF, Conde-Frieboes KW, Fels JJ, Raun K, Andersen B, Cannon B, Nedergaard J. UCP1-independent glucose-lowering effect of leptin in type 1 diabetes: only in conditions of hypoleptinemia. Am J Physiol Endocrinol Metab 2020; 318:E72-E86. [PMID: 31743040 PMCID: PMC6985793 DOI: 10.1152/ajpendo.00253.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The possibility to use leptin therapeutically for lowering glucose levels in patients with type 1 diabetes has attracted interest. However, earlier animal models of type 1 diabetes are severely catabolic with very low endogenous leptin levels, unlike most patients with diabetes. Here, we aim to test glucose-lowering effects of leptin in novel, more human-like murine models. We examined the glucose-lowering potential of leptin in diabetic models of two types: streptozotocin-treated mice and mice treated with the insulin receptor antagonist S961. To prevent hypoleptinemia, we used combinations of thermoneutral temperature and high-fat feeding. Leptin fully normalized hyperglycemia in standard chow-fed streptozotocin-treated diabetic mice. However, more humanized physiological conditions (high-fat diets or thermoneutral temperatures) that increased adiposity - and thus also leptin levels - in the diabetic mice abrogated the effects of leptin, i.e., the mice developed leptin resistance also in this respect. The glucose-lowering effect of leptin was not dependent on the presence of the uncoupling protein-1 and was not associated with alterations in plasma insulin, insulin-like growth factor 1, food intake or corticosterone but fully correlated with decreased plasma glucagon levels and gluconeogenesis. An important implication of these observations is that the therapeutic potential of leptin as an additional treatment in patients with type 1 diabetes is probably limited. This is because such patients are treated with insulin and do not display low leptin levels. Thus, the potential for a glucose-lowering effect of leptin would already have been attained with standard insulin therapy, and further effects on blood glucose level through additional leptin cannot be anticipated.
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Affiliation(s)
- Petr Zouhar
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Department of Adipose Tissue Biology, Institute of Physiology CAS, Prague, the Czech Republic
| | | | - Muhammad Hamza Bokhari
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Oliver Busby
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | | | | | | | - Kirsten Raun
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | | | - Barbara Cannon
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Jan Nedergaard
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Dimitrios P, Michael D, Vasilios K, Konstantinos S, Konstantinos I, Ioanna Z, Konstantinos P, Spyridon B, Asterios K. Liraglutide as Adjunct to Insulin Treatment in Patients with Type 1 Diabetes: A Systematic Review and Meta-analysis. Curr Diabetes Rev 2020; 16:313-326. [PMID: 31203802 DOI: 10.2174/1573399815666190614141918] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/24/2019] [Accepted: 05/03/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND A few Randomized Controlled Trials (RCTs) have evaluated the use of liraglutide in Type 1 Diabetes (T1D). Through the present systematic review and meta-analysis, we aim at critically appraising and summarizing those RCTs, providing precise effect estimates. METHODS We searched major databases and grey literature from their inception to October 2018, for RCTs with a duration ≥ 12 weeks, comparing liraglutide with placebo or any other comparator as adjunct to insulin in patients with T1D, investigating major efficacy and safety endpoints. This review is reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. RESULTS We included 5 trials with 2,445 randomized participants. Liraglutide provided modest reductions in HbA1c, with liraglutide 1.8 mg producing the greatest decrease (MD = -0.24%, 95% CI -0.32 to -0.16, I2=0%). Significant weight reduction, up to 4.87 kg with liraglutide 1.8 mg was also observed (95% CI -5.31 to -4.43, I2=0%). Decrease in total daily insulin dose, primarily driven by a decrease in bolus insulin requirements, was demonstrated. Liraglutide decreased non-significantly the odds for severe hypoglycemia (OR=0.80, 95% CI 0.57-1.14, I2=0%), while it increased significantly the odds for gastrointestinal adverse events (for nausea, OR=4.70, 95% CI 3.68-6.00, I2=37%, and for vomiting, OR=2.50, 95% CI 1.54-4.72, I2=27%). A significant increase in heart rate was also demonstrated. No association with diabetic ketoacidosis or malignancies was identified. CONCLUSION In patients with T1D, liraglutide might prove be an adjunct to insulin, improving glycemic control, inducing body weight loss and decreasing exogenous insulin requirements and severe hypoglycemia.
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Affiliation(s)
- Patoulias Dimitrios
- Second Propedeutic Department of Internal Medicine, General Hospital "Hippokration", Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Doumas Michael
- Second Propedeutic Department of Internal Medicine, General Hospital "Hippokration", Aristotle University of Thessaloniki, Thessaloniki, Greece
- VAMC and George Washington University, Washington, DC, United States
| | - Kotsis Vasilios
- Third Department of Internal Medicine, General Hospital "Papageorgiou", Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Stavropoulos Konstantinos
- Second Propedeutic Department of Internal Medicine, General Hospital "Hippokration", Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Imprialos Konstantinos
- Second Propedeutic Department of Internal Medicine, General Hospital "Hippokration", Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Zografou Ioanna
- Second Propedeutic Department of Internal Medicine, General Hospital "Hippokration", Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Petidis Konstantinos
- Second Propedeutic Department of Internal Medicine, General Hospital "Hippokration", Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Bakatselos Spyridon
- First Department of Internal Medicine, General Hospital "Hippokration", Thessaloniki, Greece
| | - Karagiannis Asterios
- Second Propedeutic Department of Internal Medicine, General Hospital "Hippokration", Aristotle University of Thessaloniki, Thessaloniki, Greece
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Musso G, Gambino R, Cassader M, Paschetta E. Efficacy and safety of dual SGLT 1/2 inhibitor sotagliflozin in type 1 diabetes: meta-analysis of randomised controlled trials. BMJ 2019; 365:l1328. [PMID: 30967375 PMCID: PMC6454301 DOI: 10.1136/bmj.l1328] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To assess the efficacy and safety of dual sodium glucose cotransporter (SGLT) 1/2 inhibitor sotagliflozin in type 1 diabetes mellitus. DESIGN Meta-analysis of randomised controlled trials. DATA SOURCES Medline; Cochrane Library; Embase; international meeting abstracts; international and national clinical trial registries; and websites of US, European, and Japanese regulatory authorities, up to 10 January 2019. ELIGIBILITY CRITERIA FOR SELECTING STUDIES Randomised controlled trials evaluating the effect of sotagliflozin versus active comparators or placebo on glycaemic and non-glycaemic outcomes and on adverse events in type 1 diabetes in participants older than 18. Three reviewers extracted data for study characteristics, outcomes of interest, and risk of bias and summarised strength of evidence using the grading of recommendations assessment, development, and evaluation approach. Main outcomes were pooled using random effects models. RESULTS Of 739 records identified, six randomised placebo controlled trials (n=3238, duration 4-52 weeks) were included. Sotagliflozin reduced levels of glycated haemoglobin (HbA1c; weighted mean difference -0.34% (95% confidence interval -0.41% to -0.27%), P<0.001); fasting plasma glucose (-16.98 mg/dL, -22.1 to -11.9; 1 mg/dL=0.0555 mmol/L) and two hour-postprandial plasma glucose (-39.2 mg/dL, -50.4 to -28.1); and daily total, basal, and bolus insulin dose (-8.99%, -10.93% to -7.05%; -8.03%, -10.14% to -5.93%; -9.14%, -12.17% to -6.12%; respectively). Sotagliflozin improved time in range (weighted mean difference 9.73%, 6.66% to 12.81%) and other continuous glucose monitoring parameters, and reduced body weight (-3.54%, -3.98% to -3.09%), systolic blood pressure (-3.85 mm Hg, -4.76 to -2.93), and albuminuria (albumin:creatinine ratio -14.57 mg/g, -26.87 to -2.28). Sotagliflozin reduced hypoglycaemia (weighted mean difference -9.09 events per patient year, -13.82 to -4.36) and severe hypoglycaemia (relative risk 0.69, 0.49 to 0.98). However, the drug increased the risk of ketoacidosis (relative risk 3.93, 1.94 to 7.96), genital tract infections (3.12, 2.14 to 4.54), diarrhoea (1.50, 1.08 to 2.10), and volume depletion events (2.19, 1.10 to 4.36). Initial HbA1c and basal insulin dose adjustment were associated with the risk of diabetic ketoacidosis. A sotagliflozin dose of 400 mg/day was associated with a greater improvement in most glycaemic and non-glycaemic outcomes than the 200 mg/day dose, without increasing the risk of adverse events. The quality of evidence was high to moderate for most outcomes, but low for major adverse cardiovascular events and all cause death. The relatively short duration of trials prevented assessment of long term outcomes. CONCLUSIONS In type 1 diabetes, sotagliflozin improves glycaemic and non-glycaemic outcomes and reduces hypoglycaemia rate and severe hypoglycaemia. The risk of diabetic ketoacidosis could be minimised by appropriate patient selection and down-titration of the basal insulin dose.
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Affiliation(s)
- Giovanni Musso
- Humanitas University Gradenigo Hospital, 8 Corso Regina Margherita, 10132 Turin, Italy
| | - Roberto Gambino
- Laboratory of Diabetes and Metabolic Disorders, Department of Medical Sciences, University of Turin, Turin, Italy
| | - Maurizio Cassader
- Laboratory of Diabetes and Metabolic Disorders, Department of Medical Sciences, University of Turin, Turin, Italy
| | - Elena Paschetta
- Humanitas University Gradenigo Hospital, 8 Corso Regina Margherita, 10132 Turin, Italy
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12
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Scarlett JM, Muta K, Brown JM, Rojas JM, Matsen ME, Acharya NK, Secher A, Ingvorsen C, Jorgensen R, Høeg-Jensen T, Stefanovski D, Bergman RN, Piccinini F, Kaiyala KJ, Shiota M, Morton GJ, Schwartz MW. Peripheral Mechanisms Mediating the Sustained Antidiabetic Action of FGF1 in the Brain. Diabetes 2019; 68:654-664. [PMID: 30523024 PMCID: PMC6385755 DOI: 10.2337/db18-0498] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 10/29/2018] [Indexed: 12/24/2022]
Abstract
We recently reported that in rodent models of type 2 diabetes (T2D), a single intracerebroventricular (icv) injection of fibroblast growth factor 1 (FGF1) induces remission of hyperglycemia that is sustained for weeks. To clarify the peripheral mechanisms underlying this effect, we used the Zucker diabetic fatty fa/fa rat model of T2D, which, like human T2D, is characterized by progressive deterioration of pancreatic β-cell function after hyperglycemia onset. We report that although icv FGF1 injection delays the onset of β-cell dysfunction in these animals, it has no effect on either glucose-induced insulin secretion or insulin sensitivity. These observations suggest that FGF1 acts in the brain to stimulate insulin-independent glucose clearance. On the basis of our finding that icv FGF1 treatment increases hepatic glucokinase gene expression, we considered the possibility that increased hepatic glucose uptake (HGU) contributes to the insulin-independent glucose-lowering effect of icv FGF1. Consistent with this possibility, we report that icv FGF1 injection increases liver glucokinase activity by approximately twofold. We conclude that sustained remission of hyperglycemia induced by the central action of FGF1 involves both preservation of β-cell function and stimulation of HGU through increased hepatic glucokinase activity.
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Affiliation(s)
- Jarrad M Scarlett
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
- Gastroenterology and Hepatology, Department of Pediatrics, University of Washington, Seattle, WA
| | - Kenjiro Muta
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Jenny M Brown
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Jennifer M Rojas
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
- Department of Physiology, Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Miles E Matsen
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Nikhil K Acharya
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | | | | | | | | | - Darko Stefanovski
- New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Richard N Bergman
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Francesca Piccinini
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Karl J Kaiyala
- Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Gregory J Morton
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Michael W Schwartz
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
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13
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Zhang Z, Hu Y, Xu N, Zhou W, Yang L, Chen R, Yang R, Sun J, Chen H. A New Way for Beta Cell Neogenesis: Transdifferentiation from Alpha Cells Induced by Glucagon-Like Peptide 1. J Diabetes Res 2019; 2019:2583047. [PMID: 31001561 PMCID: PMC6436340 DOI: 10.1155/2019/2583047] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 11/14/2018] [Accepted: 11/21/2018] [Indexed: 12/17/2022] Open
Abstract
Recent studies showed that alpha cells, especially immature cells and proalpha cells, might be the precursors of beta cells. Exposure to glucagon-like peptide 1 (GLP1) can ameliorate hyperglycemia in diabetic mice and restore the beta cell mass. In the present study, we adopted single high-dose (60 mg/kg, i.p.) streptozotocin (STZ) to model diabetes mellitus (DM) and randomly assigned short-tail (SD) rats to a normal group, a diabetic group, GLP1 groups (50 μg/kg, 100 μg/kg, and 200 μg/kg), a GLP1 (200 μg/kg) with exendin (9-39) group, and a GLP1 with LY294002 group. We found that the pancreatic insulin-glucagon-positive cell populations increased according to the increase in GLP1 exposure. By contrast, no insulin-amylase-positive cell populations or insulin/pan-cytokeratin cells were observed in the pancreatic sections. The GLP1 receptor antagonist exendin (9-39) and the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) family inhibitor LY294002 not only suppressed protein kinase B (Akt), pancreatic and duodenal homeobox 1 (Pdx1), forkhead box O 1 (FoxO1), and mast cell function-associated antigen A (MafA) mRNA expression but also increased MAFB expression. We concluded that treatment with GLP1 might result in beta cell neogenesis by promoting the transdifferentiation of alpha cells but not by pancreatic acinar cells, ductal cells, or the self-replication of beta cells. The regulation on the GLP1 receptor and its downstream transcription factor PI3K/AKT/FOXO1 pathway, which causes increased pancreatic and duodenal homeobox 1 (Pdx1) and MafA mRNA expression but causes decreased MAFB expression, may be the mechanism involved in this process.
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Affiliation(s)
- Zhen Zhang
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yinghui Hu
- Department of International Medical Center, The First Affiliated Hospital of Xi'an Jiaotong University, Shangxi, China
| | - Ningning Xu
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Wenjun Zhou
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Lei Yang
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Rongping Chen
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Rui Yang
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jia Sun
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Hong Chen
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
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14
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Buse JB, Garg SK, Rosenstock J, Bailey TS, Banks P, Bode BW, Danne T, Kushner JA, Lane WS, Lapuerta P, McGuire DK, Peters AL, Reed J, Sawhney S, Strumph P. Sotagliflozin in Combination With Optimized Insulin Therapy in Adults With Type 1 Diabetes: The North American inTandem1 Study. Diabetes Care 2018; 41:1970-1980. [PMID: 29937430 PMCID: PMC6105319 DOI: 10.2337/dc18-0343] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/25/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Evaluate the efficacy and safety of the dual sodium-glucose cotransporter 1 (SGLT1) and SGLT2 inhibitor sotagliflozin in combination with optimized insulin in type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS The inTandem1 trial, a double-blind, 52-week phase 3 trial, randomized North American adults with T1D to placebo (n = 268), sotagliflozin 200 mg (n = 263), or sotagliflozin 400 mg (n = 262) after 6 weeks of insulin optimization. The primary end point was HbA1c change from baseline at 24 weeks. HbA1c, weight, and safety were also assessed through 52 weeks. RESULTS From a mean baseline of 7.57%, placebo-adjusted HbA1c reductions were 0.36% and 0.41% with sotagliflozin 200 and 400 mg, respectively, at 24 weeks and 0.25% and 0.31% at 52 weeks (all P < 0.001). Among patients with a baseline HbA1c ≥7.0%, an HbA1c <7% was achieved by 15.7%, 27.2%, and 40.3% of patients receiving placebo, sotagliflozin 200 mg, and sotagliflozin 400 mg, respectively (P ≤ 0.003 vs. placebo) at 24 weeks. At 52 weeks, mean treatment differences between sotagliflozin 400 mg and placebo were -1.08 mmol/L for fasting plasma glucose, -4.32 kg for weight, and -15.63% for bolus insulin dose and -11.87% for basal insulin dose (all P < 0.001). Diabetes Treatment Satisfaction Questionnaire scores increased significantly by 2.5 points with sotagliflozin versus placebo (P < 0.001) at 24 weeks. Genital mycotic infections and diarrhea occurred more frequently with sotagliflozin. Adjudicated diabetic ketoacidosis (DKA) occurred in 9 (3.4%) and 11 (4.2%) patients receiving sotagliflozin 200 and 400 mg, respectively, and in 1 (0.4%) receiving placebo. Severe hypoglycemia occurred in 17 (6.5%) patients from each sotagliflozin group and 26 (9.7%) patients receiving placebo. CONCLUSIONS In a 1-year T1D study, sotagliflozin combined with optimized insulin therapy was associated with sustained HbA1c reduction, weight loss, lower insulin dose, fewer episodes of severe hypoglycemia, improved patient-reported outcomes, and more DKA relative to placebo (ClinicalTrials.gov, NCT02384941).
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Affiliation(s)
- John B Buse
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Satish K Garg
- Departments of Medicine and Pediatrics, Barbara Davis Center for Diabetes, University of Colorado Denver, Aurora, CO
| | | | | | | | - Bruce W Bode
- Atlanta Diabetes Associates, Emory University School of Medicine, Atlanta, GA
| | - Thomas Danne
- Department of Diabetes, Endocrinology, and Clinical Research, Children's and Youth Hospital Auf der Bult, Hannover Medical School, Hannover, Germany
| | - Jake A Kushner
- McNair Medical Institute and Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX
| | - Wendy S Lane
- Mountain Diabetes and Endocrine Center, Asheville, NC
| | | | - Darren K McGuire
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Anne L Peters
- Keck School of Medicine of the University of Southern California, Los Angeles, CA
| | - John Reed
- Endocrine Research Solutions, Inc., Roswell, GA
| | | | - Paul Strumph
- Lexicon Pharmaceuticals, Inc., The Woodlands, TX
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15
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Abstract
The sodium-glucose cotransporter type 1 (SGLT1) is the primary transporter for absorption of glucose and galactose in the gastrointestinal tract. Inhibition blunts and delays postprandial glucose (PPG) excursion. Sodium-glucose cotransporter type 2 (SGLT2) is expressed in the kidney, where it reabsorbs 90% of filtered glucose. Thus, a dual SGLT1 and SGLT2 inhibition (compared with selective SGLT2 inhibition) could result in lower PPG and robust A1c reduction even in patients with reduced kidney function. Sotagliflozin is an oral potent dual inhibitor of the insulin-independent SGLT1 and SGLT2. Preliminary data released from phase 2 and 3 clinical studies in adults with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) showed improved glycemic control, and met efficacy endpoints beyond A1c with a safety profile consistent with the SGLT class: significant reduction in body weight, systolic blood pressure, and efficacy maintained in lower estimated glomerular filtration rate levels with no increased hypoglycemia. Increased risk of diabetic ketoacidosis (DKA) with uncharacteristically mild-to-moderate glucose elevations (euglycemic DKA) is associated with the use of all the approved SGLT2 inhibitors. Factors that trigger DKA include insulin reductions, low caloric and fluid intake, intercurrent illness, and alcohol use. However, DKA is detectable and manageable with proper patient education. With sotagliflozin, DKA rates were not higher than the expected background rate in T1DM, but numerically higher than placebo. Sotagliflozin is the first oral SGLT1 and SGLT2 inhibitor developed for the treatment of adult patients with T1DM, in adjunct with insulin, and has the potential to address unmet needs for patients with T1DM and possibly T2DM, with a favorable benefit/risk profile.
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Affiliation(s)
- Thomas Danne
- Diabetes Center for Children and Adolescents Kinder- und Jugendkrankenhaus AUF DER BULT, Hannover, Germany
| | - Torben Biester
- Diabetes Center for Children and Adolescents Kinder- und Jugendkrankenhaus AUF DER BULT, Hannover, Germany
| | - Olga Kordonouri
- Diabetes Center for Children and Adolescents Kinder- und Jugendkrankenhaus AUF DER BULT, Hannover, Germany
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16
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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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17
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Yu X, Zhang S, Zhang L. Newer Perspectives of Mechanisms for Euglycemic Diabetic Ketoacidosis. Int J Endocrinol 2018; 2018:7074868. [PMID: 30369948 PMCID: PMC6189664 DOI: 10.1155/2018/7074868] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 07/18/2018] [Accepted: 09/09/2018] [Indexed: 12/12/2022] Open
Abstract
Euglycemic diabetic ketoacidosis (EDKA) was considered a rare condition with its specific definition and precipitating factors. However, with the wide use of sodium glucose cotransporter 2 (SGLT-2) inhibitors, the newest class of antidiabetic agents, EDKA has come back into the spotlight. Relevant cases are increasingly being reported along with insights into the mechanism of EDKA. It seems increasingly clear that EDKA is more common than we used to believe. The SGLT-2 inhibitor-associated EDKA also indicates a necessary review of our previous understanding of "diabetic" ketoacidosis, since the SGLT-2 inhibitor predisposes patients to DKA in a "starvation" way. Actually, there are growing reports about starvation-induced ketoacidosis as well. The previously "exclusive" nomenclature and cognition of these entities need to be reexamined. That the hormonal interactions in DKA may differ from the severity of insulin deficiency also may have served in the scenario of EDKA. The SGLT-2 inhibitors are newly approved in China. The main purpose of this work is to have a better understanding of the situation and update our knowledge with a focus on the pathogenesis of EDKA.
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Affiliation(s)
- Xiaofang Yu
- Department of Endocrinology, Ningbo Medical Center Lihuili Hospital, Ningbo 315040, China
| | - Saifei Zhang
- Department of Endocrinology, Ningbo Medical Center Lihuili Hospital, Ningbo 315040, China
| | - Long Zhang
- Department of Endocrinology, Ningbo Medical Center Lihuili Hospital, Ningbo 315040, China
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18
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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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19
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Holst JJ, Holland W, Gromada J, Lee Y, Unger RH, Yan H, Sloop KW, Kieffer TJ, Damond N, Herrera PL. Insulin and Glucagon: Partners for Life. Endocrinology 2017; 158:696-701. [PMID: 28323959 PMCID: PMC6061217 DOI: 10.1210/en.2016-1748] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 01/25/2017] [Indexed: 12/28/2022]
Abstract
In August 2016, several leaders in glucagon biology gathered for the European Association for the Study of Diabetes Hagedorn Workshop in Oxford, England. A key point of discussion focused on the need for basal insulin to allow for the therapeutic benefit of glucagon blockade in the treatment of diabetes. Among the most enlightening experimental results presented were findings from studies in which glucagon receptor-deficient mice were administered streptozotocin to destroy pancreatic β cells or had undergone diphtheria toxin-induced β cell ablation. This article summarizes key features of the discussion as a consensus was reached. Agents that antagonize glucagon may be of great benefit for the treatment of diabetes; however, sufficient levels of basal insulin are required for their therapeutic efficacy.
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Affiliation(s)
- Jens Juul Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - William Holland
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | | | - Young Lee
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Roger H Unger
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Hai Yan
- REMD Biotherapeutics Inc., Camarillo, California
| | - Kyle W Sloop
- Endocrine Discovery, Lilly Research Laboratories, Indianapolis, Indiana
| | - Timothy J Kieffer
- Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nicolas Damond
- Department of Genetic Medicine & Development, Faculty of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Pedro L Herrera
- Department of Genetic Medicine & Development, Faculty of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland
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20
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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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21
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Xu Y, Tong Q. Central leptin action on euglycemia restoration in type 1 diabetes: Restraining responses normally induced by fasting? Int J Biochem Cell Biol 2016; 88:198-203. [PMID: 27702650 DOI: 10.1016/j.biocel.2016.09.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/27/2016] [Accepted: 09/30/2016] [Indexed: 01/29/2023]
Abstract
Leptin monotherapy is sufficient to restore euglycemia in insulinopenic type 1 diabetes (T1D), yet the underlying mechanism remains poorly understood. Accumulating evidence demonstrates that the brain mediates the leptin action on euglycemia restoration. Here, we first review evidence supporting that symptoms in T1D resemble an uncontrolled response to fasting. Then, we discuss recent research progress on brain neurons and their neurotransmitters that potentially mediate the leptin action. Finally, peripheral effective pathways, which are normally involved in fasting responses and associated with leptin action on euglycemia restoration in T1D, will also be discussed. This summary complements several previous excellent reviews on this topic (Meek and Morton, 2016; Perry et al., 2016; Fujikawa and Coppari, 2015). A deep understanding of neurocircuitry and the peripheral effective pathways that mediate the leptin action on euglycemia restoration will likely lead to novel targets for an insulin-independent therapeutics against T1D.
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Affiliation(s)
- Yuanzhong Xu
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, United States
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, United States.
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Neumann UH, Ho JSS, Mojibian M, Covey SD, Charron MJ, Kieffer TJ. Glucagon receptor gene deletion in insulin knockout mice modestly reduces blood glucose and ketones but does not promote survival. Mol Metab 2016; 5:731-736. [PMID: 27656411 PMCID: PMC5021664 DOI: 10.1016/j.molmet.2016.05.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 05/25/2016] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE It has been thought that the depletion of insulin is responsible for the catabolic consequences of diabetes; however, evidence suggests that glucagon also plays a role in diabetes pathogenesis. Glucagon suppression by glucagon receptor (Gcgr) gene deletion, glucagon immunoneutralization, or Gcgr antagonist can reverse or prevent type 1 diabetes in rodents suggesting that dysregulated glucagon is also required for development of diabetic symptoms. However, the models used in these studies were rendered diabetic by chemical- or immune-mediated β-cell destruction, in which insulin depletion is incomplete. Therefore, it is unclear whether glucagon suppression could overcome the consequence of the complete lack of insulin. METHODS To directly test this we characterized mice that lack the Gcgr and both insulin genes (GcgrKO/InsKO). RESULTS In both P1 pups and mice that were kept alive to young adulthood using insulin therapy, blood glucose and plasma ketones were modestly normalized; however, mice survived for only up to 6 days, similar to GcgrHet/InsKO controls. In addition, Gcgr gene deletion was unable to normalize plasma leptin levels, triglycerides, fatty acids, or hepatic cholesterol accumulation compared to GcgrHet/InsKO controls. CONCLUSION Therefore, the metabolic manifestations associated with a complete lack of insulin cannot be overcome by glucagon receptor gene inactivation.
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Affiliation(s)
- Ursula H Neumann
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Jessica S S Ho
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Majid Mojibian
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Scott D Covey
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Maureen J Charron
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
| | - 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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Abstract
While it is well established that the adiposity hormone leptin plays a key role in the regulation of energy homeostasis, growing evidence suggests that leptin is also critical for glycaemic control. In this review we examine the role of the brain in the glucose-lowering actions of leptin and the potential mediators responsible for driving hyperglycaemia in states of uncontrolled insulin-deficient diabetes (uDM). These considerations highlight the possibility of targeting leptin-sensitive pathways as a therapeutic option for the treatment of diabetes. This review summarises a presentation given at the 'Is leptin coming back?' symposium at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by Christoffer Clemmensen and colleagues, DOI: 10.1007/s00125-016-3906-7 , and by Gerald Shulman and colleagues, DOI: 10.1007/s00125-016-3909-4 ) and an overview by the Session Chair, Ulf Smith (DOI: 10.1007/s00125-016-3894-7 ).
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Affiliation(s)
- Thomas H Meek
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington at South Lake Union, 850 Republican St., N335, Box 358055, Seattle, WA, 98195, USA
| | - Gregory J Morton
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington at South Lake Union, 850 Republican St., N335, Box 358055, Seattle, WA, 98195, USA.
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Abate N, Chandalia M. SGLT2 Inhibitors and Ketoacidosis: Cause for Concern? Metab Syndr Relat Disord 2016; 14:1-2. [DOI: 10.1089/met.2015.29002.aba] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Nicola Abate
- Division of Endocrinology, University of Texas Medical Branch, Galveston, Texas
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Morton GJ, Meek TH, Matsen ME, Schwartz MW. Evidence against hypothalamic-pituitary-adrenal axis suppression in the antidiabetic action of leptin. J Clin Invest 2015; 125:4587-91. [PMID: 26529250 DOI: 10.1172/jci82723] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 09/28/2015] [Indexed: 12/11/2022] Open
Abstract
Leptin administration restores euglycemia in rodents with severe insulin-deficient diabetes, and recent studies to explain this phenomenon have focused on the ability of leptin to normalize excessive hypothalamic-pituitary-adrenal (HPA) axis activity. Here, we employed a streptozotocin-induced rat model (STZ-DM) of uncontrolled insulin-deficient diabetes mellitus (uDM) to investigate the contribution of HPA axis suppression to leptin-mediated glucose lowering. Specifically, we asked if HPA axis activation is required for diabetic hyperglycemia, whether HPA axis normalization can be achieved using a dose of leptin below that needed to normalize glycemia, and if the ability of leptin to lower plasma glucocorticoid levels is required for its antidiabetic action. In STZ-DM rats, neither adrenalectomy-induced (ADX-induced) glucocorticoid deficiency nor pharmacological glucocorticoid receptor blockade lowered elevated blood glucose levels. Although elevated plasma levels of corticosterone were normalized by i.v. leptin infusion at a dose that raises low plasma levels into the physiological range, diabetic hyperglycemia was not altered. Lastly, the potent glucose-lowering effect of continuous intracerebroventricular leptin infusion was not impacted by systemic administration of corticosterone at a dose that maintained elevated plasma levels characteristic of STZ-DM. We conclude that, although restoring low plasma leptin levels into the physiological range effectively normalizes increased HPA axis activity in rats with uDM, this effect is neither necessary nor sufficient to explain leptin's antidiabetic action.
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