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Kusters YHAM, Barrett EJ. Muscle microvasculature's structural and functional specializations facilitate muscle metabolism. Am J Physiol Endocrinol Metab 2016; 310:E379-87. [PMID: 26714849 PMCID: PMC4888529 DOI: 10.1152/ajpendo.00443.2015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/18/2015] [Indexed: 12/29/2022]
Abstract
We review the evolving findings from studies that examine the relationship between the structural and functional properties of skeletal muscle's vasculature and muscle metabolism. Unique aspects of the organization of the muscle microvasculature are highlighted. We discuss the role of vasomotion at the microscopic level and of flowmotion at the tissue level as modulators of perfusion distribution in muscle. We then consider in some detail how insulin and exercise each modulate muscle perfusion at both the microvascular and whole tissue level. The central role of the vascular endothelial cell in modulating both perfusion and transendothelial insulin and nutrient transport is also reviewed. The relationship between muscle metabolic insulin resistance and the vascular action of insulin in muscle continues to indicate an important role for the microvasculature as a target for insulin action and that impairing insulin's microvascular action significantly affects body glucose metabolism.
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Affiliation(s)
- Yvo H A M Kusters
- Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands; Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, Maastricht, The Netherlands; and
| | - Eugene J Barrett
- Department of Medicine, Pediatrics, and Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia
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52
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Zhou X, Lin A, Yuan X, Li H, Ma D, Xue W. Glucose-sensitive and blood-compatible nanogels for insulin controlled release. J Appl Polym Sci 2016. [DOI: 10.1002/app.43504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Xiaoyan Zhou
- Key Laboratory of Biomaterials of Guangdong Higher Education Institutes; Department of Biomedical Engineering; Jinan University; Guangzhou 510632 China
| | - Anhua Lin
- Department of Endocrinology; Jiangxi Provincial People's Hospital; Nanchang 330006 China
| | - Xinxin Yuan
- Department of Endocrinology; Jiangxi Provincial People's Hospital; Nanchang 330006 China
| | - Hui Li
- Key Laboratory of Biomaterials of Guangdong Higher Education Institutes; Department of Biomedical Engineering; Jinan University; Guangzhou 510632 China
| | - Dong Ma
- Key Laboratory of Biomaterials of Guangdong Higher Education Institutes; Department of Biomedical Engineering; Jinan University; Guangzhou 510632 China
| | - Wei Xue
- Key Laboratory of Biomaterials of Guangdong Higher Education Institutes; Department of Biomedical Engineering; Jinan University; Guangzhou 510632 China
- Institute of Life and Health Engineering Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes; Jinan University; Guangzhou 510632 China
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53
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Urayama A, Grubb JH, Sly WS, Banks WA. Pharmacologic manipulation of lysosomal enzyme transport across the blood-brain barrier. J Cereb Blood Flow Metab 2016; 36:476-86. [PMID: 26661222 PMCID: PMC4794098 DOI: 10.1177/0271678x15614589] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/24/2015] [Indexed: 12/22/2022]
Abstract
The adult blood-brain barrier, unlike the neonatal blood-brain barrier, does not transport lysosomal enzymes into brain, making enzyme replacement therapy ineffective in treating the central nervous system symptoms of lysosomal storage diseases. However, enzyme transport can be re-induced with alpha-adrenergics. Here, we examined agents that are known to alter the blood-brain barrier transport of large molecules or to induce lysosomal enzyme transport across the blood-brain barrier ((±)epinephrine, insulin, retinoic acid, and lipopolysaccharide) in 2-week-old and adult mice. In 2-week-old adolescent mice, all these pharmacologic agents increased brain and heart uptake of phosphorylated human β-glucuronidase. In 8-week-old adult mice, manipulations with (±)epinephrine, insulin, and retinoic acid were significantly effective on uptake by brain and heart. The increased uptake of phosphorylated human β-glucuronidase was inhibited by mannose 6-phosphate for the agents (±)epinephrine and retinoic acid and by L-NG-nitroarginine methyl ester for the agent lipopolysaccharide in neonatal and adult mice. An in situ brain perfusion study revealed that retinoic acid directly modulated the transport of phosphorylated human β-glucuronidase across the blood-brain barrier. The present study indicates that there are multiple opportunities to at least transiently induce phosphorylated human β-glucuronidase transport at the adult blood-brain barrier.
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Affiliation(s)
- Akihiko Urayama
- Department of Neurology, University of Texas Medical School at Houston, Houston, TX, USA
| | - Jeffrey H Grubb
- Lysosomal Research, Ultragenyx Pharmaceutical Inc., Novato, CA, USA Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - William S Sly
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - William A Banks
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA; Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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Wellhauser L, Chalmers JA, Belsham DD. Nitric Oxide Exerts Basal and Insulin-Dependent Anorexigenic Actions in POMC Hypothalamic Neurons. Mol Endocrinol 2016; 30:402-16. [PMID: 26930171 DOI: 10.1210/me.2015-1275] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The arcuate nucleus of the hypothalamus represents a key center for the control of appetite and feeding through the regulation of 2 key neuronal populations, notably agouti-related peptide/neuropeptide Y and proopimelanocortin (POMC)/cocaine- and amphetamine-regulated transcript neurons. Altered regulation of these neuronal networks, in particular the dysfunction of POMC neurons upon high-fat consumption, is a major pathogenic mechanism involved in the development of obesity and type 2 diabetes mellitus. Efforts are underway to preserve the integrity or enhance the functionality of POMC neurons in order to prevent or treat these metabolic diseases. Here, we report for the first time that the nitric oxide (NO(-)) donor, sodium nitroprusside (SNP) mediates anorexigenic actions in both hypothalamic tissue and hypothalamic-derived cell models by mediating the up-regulation of POMC levels. SNP increased POMC mRNA in a dose-dependent manner and enhanced α-melanocortin-secreting hormone production and secretion in mHypoA-POMC/GFP-2 cells. SNP also enhanced insulin-driven POMC expression likely by inhibiting the deacetylase activity of sirtuin 1. Furthermore, SNP enhanced insulin-dependent POMC expression, likely by reducing the transcriptional repression of Foxo1 on the POMC gene. Prolonged SNP exposure prevented the development of insulin resistance. Taken together, the NO(-) donor SNP enhances the anorexigenic potential of POMC neurons by promoting its transcriptional expression independent and in cooperation with insulin. Thus, increasing cellular NO(-) levels represents a hormone-independent method of promoting anorexigenic output from the existing POMC neuronal populations and may be advantageous in the fight against these prevalent disorders.
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Affiliation(s)
- Leigh Wellhauser
- Department of Physiology (L.W., J.A.C., D.D.B.), University of Toronto, Toronto, Ontario, Canada M5G 1A8; and Departments of Obstetrics, Gynaecology, and Medicine (D.D.B.), University of Toronto and Division of Cellular and Molecular Biology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada M5S 1A8
| | - Jennifer A Chalmers
- Department of Physiology (L.W., J.A.C., D.D.B.), University of Toronto, Toronto, Ontario, Canada M5G 1A8; and Departments of Obstetrics, Gynaecology, and Medicine (D.D.B.), University of Toronto and Division of Cellular and Molecular Biology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada M5S 1A8
| | - Denise D Belsham
- Department of Physiology (L.W., J.A.C., D.D.B.), University of Toronto, Toronto, Ontario, Canada M5G 1A8; and Departments of Obstetrics, Gynaecology, and Medicine (D.D.B.), University of Toronto and Division of Cellular and Molecular Biology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada M5S 1A8
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Abstract
Nitric oxide (NO) generated by endothelial cells to relax vascular smooth muscle is one of the most intensely studied molecules in the past 25 years. Much of what is known about NO regulation of NO is based on blockade of its generation and analysis of changes in vascular regulation. This approach has been useful to demonstrate the importance of NO in large scale forms of regulation but provides less information on the nuances of NO regulation. However, there is a growing body of studies on multiple types of in vivo measurement of NO in normal and pathological conditions. This discussion will focus on in vivo studies and how they are reshaping the understanding of NO's role in vascular resistance regulation and the pathologies of hypertension and diabetes mellitus. The role of microelectrode measurements in the measurement of [NO] will be considered because much of the controversy about what NO does and at what concentration depends upon the measurement methodology. For those studies where the technology has been tested and found to be well founded, the concept evolving is that the stresses imposed on the vasculature in the form of flow-mediated stimulation, chemicals within the tissue, and oxygen tension can cause rapid and large changes in the NO concentration to affect vascular regulation. All these functions are compromised in both animal and human forms of hypertension and diabetes mellitus due to altered regulation of endothelial cells and formation of oxidants that both damage endothelial cells and change the regulation of endothelial nitric oxide synthase.
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Affiliation(s)
- Harold Glenn Bohlen
- Department of Cellular and Integrative Physiology, Indiana University Medical School, Indianapolis, Indiana, Indiana, USA
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56
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Molina MN, Ferder L, Manucha W. Emerging Role of Nitric Oxide and Heat Shock Proteins in Insulin Resistance. Curr Hypertens Rep 2015; 18:1. [DOI: 10.1007/s11906-015-0615-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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57
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Capel F, Chabrier G, Pitois E, Rigaudière JP, Le Plenier S, Durand C, Jouve C, de Bandt JP, Cynober L, Moinard C, Morio B. Combining citrulline with atorvastatin preserves glucose homeostasis in a murine model of diet-induced obesity. Br J Pharmacol 2015; 172:4996-5008. [PMID: 26228176 DOI: 10.1111/bph.13269] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/26/2015] [Accepted: 07/25/2015] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE NO is a crucial regulator of energy and lipid metabolism, whose homeostasis is compromised during obesity. Combination of citrulline and atorvastatin potentiated NO production in vitro. Here we have assessed the effects of this combination in mice with diet-induced obesity (DIO). EXPERIMENTAL APPROACH C57BL/6J male mice were given a standard diet (control) or a high fat-high sucrose diet (DIO) for 8 weeks. DIO mice were then treated with DIO alone, DIO with citrulline, DIO with atorvastatin or DIO with citrulline and atorvastatin (DIOcit-stat) for 3 weeks. Thereafter, body composition, glucose tolerance, insulin sensitivity and liver fat metabolism were measured. KEY RESULTS DIOcit-stat mice showed lower body weight, fat mass and epididymal fat depots compared with other DIO groups. Unlike other DIO groups, glucose tolerance and insulin sensitivity of DIOcit-stat, along with blood glucose and insulin concentrations in response to feeding, were restored to control values. Refeeding-induced changes in liver lipogenic activity were also reduced in DIOcit-stat mice compared with those of DIO animals. This was associated with decreased gene expression of the transcription factor SREBP-1, liver X receptor α, ChREBP and of target lipogenic enzymes in the liver of DIOcit-stat mice compared with those of other DIO groups. CONCLUSIONS AND IMPLICATIONS The citrulline-atorvastatin combination prevented fat mass accumulation and maintained glucose homeostasis in DIO mice. Furthermore, it potentiated inhibition of hepatic de novo lipogenesis activity. This combination has potential for preservation of glucose homeostasis in patients receiving statin therapy.
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Affiliation(s)
- Frédéric Capel
- INRA, UMR 1019, UNH, CRNH Auvergne and Clermont University, Auvergne University, Human Nutrition Unit, Clermont-Ferrand, France
| | - Gwladys Chabrier
- INRA, UMR 1019, UNH, CRNH Auvergne and Clermont University, Auvergne University, Human Nutrition Unit, Clermont-Ferrand, France
| | - Elodie Pitois
- INRA, UMR 1019, UNH, CRNH Auvergne and Clermont University, Auvergne University, Human Nutrition Unit, Clermont-Ferrand, France
| | - Jean-Paul Rigaudière
- INRA, UMR 1019, UNH, CRNH Auvergne and Clermont University, Auvergne University, Human Nutrition Unit, Clermont-Ferrand, France
| | - Servane Le Plenier
- Laboratory of Nutrition Biology EA 4466, Paris-Descartes University, Paris, France
| | - Christine Durand
- INRA, UMR 1397, CarMeN Laboratory, Lyon 1 University, INSERM U1060, INSA of Lyon, Rockefeller and Charles Merieux Lyon-Sud Medical Universities, Lyon, France
| | - Chrystèle Jouve
- INRA, UMR 1019, UNH, CRNH Auvergne and Clermont University, Auvergne University, Human Nutrition Unit, Clermont-Ferrand, France
| | - Jean-Pascal de Bandt
- Laboratory of Nutrition Biology EA 4466, Paris-Descartes University, Paris, France.,Department of Clinical Chemistry, Cochin and Hotel-Dieu Hospitals, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Luc Cynober
- Laboratory of Nutrition Biology EA 4466, Paris-Descartes University, Paris, France.,Department of Clinical Chemistry, Cochin and Hotel-Dieu Hospitals, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Christophe Moinard
- Laboratory of Nutrition Biology EA 4466, Paris-Descartes University, Paris, France
| | - Béatrice Morio
- INRA, UMR 1019, UNH, CRNH Auvergne and Clermont University, Auvergne University, Human Nutrition Unit, Clermont-Ferrand, France.,INRA, UMR 1397, CarMeN Laboratory, Lyon 1 University, INSERM U1060, INSA of Lyon, Rockefeller and Charles Merieux Lyon-Sud Medical Universities, Lyon, France
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58
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Kobayashi J, Ohtake K, Uchida H. NO-Rich Diet for Lifestyle-Related Diseases. Nutrients 2015; 7:4911-37. [PMID: 26091235 PMCID: PMC4488823 DOI: 10.3390/nu7064911] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 02/07/2023] Open
Abstract
Decreased nitric oxide (NO) availability due to obesity and endothelial dysfunction might be causally related to the development of lifestyle-related diseases such as insulin resistance, ischemic heart disease, and hypertension. In such situations, instead of impaired NO synthase (NOS)-dependent NO generation, the entero-salivary nitrate-nitrite-NO pathway might serve as a backup system for NO generation by transmitting NO activities in the various molecular forms including NO and protein S-nitrosothiols. Recently accumulated evidence has demonstrated that dietary intake of fruits and vegetables rich in nitrate/nitrite is an inexpensive and easily-practicable way to prevent insulin resistance and vascular endothelial dysfunction by increasing the NO availability; a NO-rich diet may also prevent other lifestyle-related diseases, including osteoporosis, chronic obstructive pulmonary disease (COPD), and cancer. This review provides an overview of our current knowledge of NO generation through the entero-salivary pathway and discusses its safety and preventive effects on lifestyle-related diseases.
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Affiliation(s)
- Jun Kobayashi
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama 350-0295, Japan.
| | - Kazuo Ohtake
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama 350-0295, Japan.
| | - Hiroyuki Uchida
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama 350-0295, Japan.
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59
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Wang H, Wang AX, Aylor K, Barrett EJ. Caveolin-1 phosphorylation regulates vascular endothelial insulin uptake and is impaired by insulin resistance in rats. Diabetologia 2015; 58:1344-53. [PMID: 25748795 PMCID: PMC4417063 DOI: 10.1007/s00125-015-3546-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 02/13/2015] [Indexed: 10/25/2022]
Abstract
AIMS/HYPOTHESIS As insulin entry into muscle interstitium is rate-limiting for its overall peripheral action, defining the route and regulation of its entry is critical. Caveolin-1 is required for caveola formation in vascular endothelial cells (ECs) and for EC insulin uptake. Whether this requirement reflects simply the need for caveola availability or involves a more active role for caveolae/caveolin-1 is not known. Here, we examined the role of insulin-stimulated tyrosine 14 (Tyr(14))-caveolin-1 phosphorylation in mediating EC insulin uptake and the role of cellular Src-kinase (cSrc), TNF-α/IL-6 and high fat diet (HFD) in regulating this process. METHODS Freshly isolated ECs from normal or HFD-fed rats and/or cultured ECs were treated with FITC-labelled or regular insulin with or without a Src or phosphotidylinositol-3-kinase inhibitor, TNF-α or IL-6, or transfecting FLAG-tagged wild-type (WT) or mutant (Y14F) caveolin-1. Tyr(14)-caveolin-1/Tyr(416) cSrc phosphorylation and FITC-insulin uptake were quantified by immunostaining and/or western blots. RESULTS Insulin stimulated Tyr(14)-caveolin-1 phosphorylation during EC insulin uptake. Inhibiting cSrc, but not phosphotidylinositol-3-kinase, reduced insulin-stimulated caveolin-1 phosphorylation. Furthermore, inhibiting cSrc reduced FITC-insulin uptake by ∼50%. Overexpression of caveolin-1Y14F inhibited, while overexpression of WT caveolin-1 increased, FITC-insulin uptake. Exposure of ECs to TNF-α or IL-6, or to 1-week HFD feeding eliminated insulin-stimulated caveolin-1 phosphorylation and inhibited FITC-insulin uptake to a similar extent. CONCLUSIONS/INTERPRETATION Insulin stimulation of its own uptake requires caveolin-1 phosphorylation and Src-kinase activity. HFD in vivo and proinflammatory cytokines in vitro both inhibit this process.
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Affiliation(s)
- Hong Wang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Virginia Health System, 450 Ray C. Hunt Drive, Box 801410, Charlottesville, VA, 22908, USA,
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60
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Tissue inflammation and nitric oxide-mediated alterations in cardiovascular function are major determinants of endotoxin-induced insulin resistance. Cardiovasc Diabetol 2015; 14:56. [PMID: 25986700 PMCID: PMC4484635 DOI: 10.1186/s12933-015-0223-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/05/2015] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Endotoxin (i.e. LPS) administration induces a robust inflammatory response with accompanying cardiovascular dysfunction and insulin resistance. Overabundance of nitric oxide (NO) contributes to the vascular dysfunction. However, inflammation itself also induces insulin resistance in skeletal muscle. We sought to investigate whether the cardiovascular dysfunction induced by increased NO availability without inflammatory stress can promote insulin resistance. Additionally, we examined the role of inducible nitric oxide synthase (iNOS or NOS2), the source of the increase in NO availability, in modulating LPS-induced decrease in insulin-stimulated muscle glucose uptake (MGU). METHODS The impact of NO donor infusion on insulin-stimulated whole-body and muscle glucose uptake (hyperinsulinemic-euglycemic clamps), and the cardiovascular system was assessed in chronically catheterized, conscious mice wild-type (WT) mice. The impact of LPS on insulin action and the cardiovascular system were assessed in WT and global iNOS knockout (KO) mice. Tissue blood flow and cardiac function were assessed using microspheres and echocardiography, respectively. Insulin signaling activity, and gene expression of pro-inflammatory markers were also measured. RESULTS NO donor infusion decreased mean arterial blood pressure, whole-body glucose requirements, and MGU in the absence of changes in skeletal muscle blood flow. LPS lowered mean arterial blood pressure and glucose requirements in WT mice, but not in iNOS KO mice. Lastly, despite an intact inflammatory response, iNOS KO mice were protected from LPS-mediated deficits in cardiac output. LPS impaired MGU in vivo, regardless of the presence of iNOS. However, ex vivo, insulin action in muscle obtained from LPS treated iNOS KO animals was protected. CONCLUSION Nitric oxide excess and LPS impairs glycemic control by diminishing MGU. LPS impairs MGU by both the direct effect of inflammation on the myocyte, as well as by the indirect NO-driven cardiovascular dysfunction.
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Wagenmakers AJM, Strauss JA, Shepherd SO, Keske MA, Cocks M. Increased muscle blood supply and transendothelial nutrient and insulin transport induced by food intake and exercise: effect of obesity and ageing. J Physiol 2015; 594:2207-22. [PMID: 25627798 DOI: 10.1113/jphysiol.2014.284513] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/20/2015] [Indexed: 01/07/2023] Open
Abstract
This review concludes that a sedentary lifestyle, obesity and ageing impair the vasodilator response of the muscle microvasculature to insulin, exercise and VEGF-A and reduce microvascular density. Both impairments contribute to the development of insulin resistance, obesity and chronic age-related diseases. A physically active lifestyle keeps both the vasodilator response and microvascular density high. Intravital microscopy has shown that microvascular units (MVUs) are the smallest functional elements to adjust blood flow in response to physiological signals and metabolic demands on muscle fibres. The luminal diameter of a common terminal arteriole (TA) controls blood flow through up to 20 capillaries belonging to a single MVU. Increases in plasma insulin and exercise/muscle contraction lead to recruitment of additional MVUs. Insulin also increases arteriolar vasomotion. Both mechanisms increase the endothelial surface area and therefore transendothelial transport of glucose, fatty acids (FAs) and insulin by specific transporters, present in high concentrations in the capillary endothelium. Future studies should quantify transporter concentration differences between healthy and at risk populations as they may limit nutrient supply and oxidation in muscle and impair glucose and lipid homeostasis. An important recent discovery is that VEGF-B produced by skeletal muscle controls the expression of FA transporter proteins in the capillary endothelium and thus links endothelial FA uptake to the oxidative capacity of skeletal muscle, potentially preventing lipotoxic FA accumulation, the dominant cause of insulin resistance in muscle fibres.
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Affiliation(s)
- Anton J M Wagenmakers
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Juliette A Strauss
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Sam O Shepherd
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Michelle A Keske
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Matthew Cocks
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
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Nitric oxide-dependent vasodilation and Ca2+signalling induced by erythrodiol in rat aorta. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2015. [DOI: 10.1016/s2222-1808(15)60892-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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63
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Azizi PM, Zyla RE, Guan S, Wang C, Liu J, Bolz SS, Heit B, Klip A, Lee WL. Clathrin-dependent entry and vesicle-mediated exocytosis define insulin transcytosis across microvascular endothelial cells. Mol Biol Cell 2014; 26:740-50. [PMID: 25540431 PMCID: PMC4325843 DOI: 10.1091/mbc.e14-08-1307] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
How insulin traverses the continuous endothelium of the microvasculature has been poorly studied. Development of a novel assay to measure insulin transcytosis reveals an unexpected role for clathrin in insulin transendothelial transport. Insulin transcytosis is dynamin and clathrin dependent but does not require cholesterol or caveolin-1. Transport of insulin across the microvasculature is necessary to reach its target organs (e.g., adipose and muscle tissues) and is rate limiting in insulin action. Morphological evidence suggests that insulin enters endothelial cells of the microvasculature, and studies with large vessel–derived endothelial cells show insulin uptake; however, little is known about the actual transcytosis of insulin and how this occurs in the relevant microvascular endothelial cells. We report an approach to study insulin transcytosis across individual, primary human adipose microvascular endothelial cells (HAMECs), involving insulin uptake followed by vesicle-mediated exocytosis visualized by total internal reflection fluorescence microscopy. In this setting, fluorophore-conjugated insulin exocytosis depended on its initial binding and uptake, which was saturable and much greater than in muscle cells. Unlike its degradation within muscle cells, insulin was stable within HAMECs and escaped lysosomal colocalization. Insulin transcytosis required dynamin but was unaffected by caveolin-1 knockdown or cholesterol depletion. Instead, insulin transcytosis was significantly inhibited by the clathrin-mediated endocytosis inhibitor Pitstop 2 or siRNA-mediated clathrin depletion. Accordingly, insulin internalized for 1 min in HAMECs colocalized with clathrin far more than with caveolin-1. This study constitutes the first evidence of vesicle-mediated insulin transcytosis and highlights that its initial uptake is clathrin dependent and caveolae independent.
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Affiliation(s)
- Paymon M Azizi
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada Keenan Research Centre, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada Programme in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Roman E Zyla
- Keenan Research Centre, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada
| | - Sha Guan
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada Keenan Research Centre, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada Programme in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Changsen Wang
- Keenan Research Centre, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada
| | - Jun Liu
- Programme in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | | | - Bryan Heit
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Amira Klip
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada Programme in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Warren L Lee
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada Keenan Research Centre, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada Interdepartmental Division of Critical Care, Department of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
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64
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Manrique C, Sowers JR. Insulin resistance and skeletal muscle vasculature: significance, assessment and therapeutic modulators. Cardiorenal Med 2014; 4:244-56. [PMID: 25737689 DOI: 10.1159/000368423] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 08/27/2014] [Indexed: 01/02/2023] Open
Abstract
Overnutrition and sedentarism are closely related to the alarming incidence of obesity and type 2 diabetes mellitus (DM2) in the Western world. Resistance to the actions of insulin is a common occurrence in conditions such as obesity, hypertension and DM2. In the skeletal muscle vasculature, insulin promotes vasodilation and its own transport across the vascular wall to reach its target tissue. Furthermore, insulin resistance (IR) in the skeletal muscle vasculature results in impaired skeletal muscle glucose uptake and altered whole-body glucose homeostasis. The development of different invasive and noninvasive techniques has allowed the characterization of the actions of insulin and other vasoactive hormones in the skeletal muscle vasculature in both health and disease. Current treatment strategies for DM2 do not necessarily address the impaired effect of insulin in the vasculature. Understanding the effects of insulin and other metabolically active hormones in the vasculature should facilitate the development of new therapeutic strategies targeted at the modulation of IR and improvement of whole-body glucose tolerance.
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Affiliation(s)
- Camila Manrique
- Division of Endocrinology, Department of Internal Medicine, Columbia, Mo., USA ; Harry S. Truman Memorial Veteran's Hospital, Columbia, Mo., USA
| | - James R Sowers
- Division of Endocrinology, Department of Internal Medicine, Columbia, Mo., USA ; Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Mo., USA ; Harry S. Truman Memorial Veteran's Hospital, Columbia, Mo., USA
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Abstract
We have learned over the last several decades that the brain is an important target for insulin action. Insulin in the central nervous system (CNS) affects feeding behavior and body energy stores, the metabolism of glucose and fats in the liver and adipose, and various aspects of memory and cognition. Insulin may even influence the development or progression of Alzheimer disease. Yet, a number of seemingly simple questions (e.g., What is the pathway for delivery of insulin to the brain? Is insulin's delivery to the brain mediated by the insulin receptor and is it a regulated process? Is brain insulin delivery affected by insulin resistance?) are unanswered. Here we briefly review accumulated findings affirming the importance of insulin as a CNS regulatory peptide, examine the current understanding of how peripheral insulin is delivered to the brain, and identify key gaps in the current understanding of this process.
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Affiliation(s)
- Sarah M Gray
- Division of Endocrinology, Department of Medicine, University of Virginia, School of Medicine, Charlottesville, VA
| | - Rick I Meijer
- Division of Endocrinology, Department of Medicine, University of Virginia, School of Medicine, Charlottesville, VA
| | - Eugene J Barrett
- Division of Endocrinology, Department of Medicine, University of Virginia, School of Medicine, Charlottesville, VA
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66
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Ohtake K, Nakano G, Ehara N, Sonoda K, Ito J, Uchida H, Kobayashi J. Dietary nitrite supplementation improves insulin resistance in type 2 diabetic KKA(y) mice. Nitric Oxide 2014; 44:31-8. [PMID: 25461271 DOI: 10.1016/j.niox.2014.11.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 11/03/2014] [Accepted: 11/11/2014] [Indexed: 01/30/2023]
Abstract
BACKGROUND Because insulin signaling is essential for endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) production, the loss of bioavailable NO might be a common molecular mechanism underlying the development of insulin resistance and endothelial dysfunction. Although dietary nitrite acts as a substrate for systemic NO generation, thereby serving as a physiological alternative source of NO for signaling, it is not precisely known how dietary nitrite affects type 2 diabetes mellitus. Here we report the therapeutic effects of dietary nitrite on the metabolic and histological features of KKA(y) diabetic mice. METHODS KKA(y) mice were divided into three groups (without nitrite, and with 50 mg/L and 150 mg/L nitrite in drinking water), and two groups of C57BL/6J mice served as controls (without nitrite and with 150 mg/L nitrite in drinking water). After 10 weeks, blood samples, visceral adipose tissues, and gastrocnemius muscles were collected after a 16-hour fast to assess the homeostasis model assessment of insulin resistance (HOMA-IR) levels, the histology of the adipose tissue, insulin-stimulated sequential signaling to glucose transporter 4 (GLUT4), and nitrite and nitrate contents in the muscle using an HPLC system. RESULTS KKA(y) mice developed obesity with enhanced fasting plasma levels of glucose and insulin and exhibited increased HOMA-IR scores compared with the C57BL/6J control mice. Dietary nitrite dose-dependently reduced the size of the hypertrophic adipocytes and TNF-α transcription in the adipose tissue of KKA(y) diabetic mice, which also restored the insulin-mediated signal transduction, including p85 and Akt phosphorylation, and subsequently restored the GLUT4 expression in the skeletal muscles. CONCLUSIONS These results suggest that dietary nitrite provides an alternative source of NO, and subsequently improves the insulin-mediated signaling and the metabolic and histological features in KKA(y) diabetic mice.
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Affiliation(s)
- Kazuo Ohtake
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama, Japan
| | - Genya Nakano
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama, Japan
| | - Nobuyuki Ehara
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama, Japan
| | - Kunihiro Sonoda
- Department of Food and Nutritional Environment, College of Human Life and Environment, Kinjo Gakuin University, Nagoya, Japan
| | - Junta Ito
- Division of Oral Anatomy, Department of Human Development and Fostering, Meikai University School of Dentistry, Saitama, Japan
| | - Hiroyuki Uchida
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama, Japan
| | - Jun Kobayashi
- Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Science, Josai University, Saitama, Japan.
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67
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Sansbury BE, Hill BG. Regulation of obesity and insulin resistance by nitric oxide. Free Radic Biol Med 2014; 73:383-99. [PMID: 24878261 PMCID: PMC4112002 DOI: 10.1016/j.freeradbiomed.2014.05.016] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 02/07/2023]
Abstract
Obesity is a risk factor for developing type 2 diabetes and cardiovascular disease and has quickly become a worldwide pandemic with few tangible and safe treatment options. Although it is generally accepted that the primary cause of obesity is energy imbalance, i.e., the calories consumed are greater than are utilized, understanding how caloric balance is regulated has proven a challenge. Many "distal" causes of obesity, such as the structural environment, occupation, and social influences, are exceedingly difficult to change or manipulate. Hence, molecular processes and pathways more proximal to the origins of obesity-those that directly regulate energy metabolism or caloric intake-seem to be more feasible targets for therapy. In particular, nitric oxide (NO) is emerging as a central regulator of energy metabolism and body composition. NO bioavailability is decreased in animal models of diet-induced obesity and in obese and insulin-resistant patients, and increasing NO output has remarkable effects on obesity and insulin resistance. This review discusses the role of NO in regulating adiposity and insulin sensitivity and places its modes of action into context with the known causes and consequences of metabolic disease.
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Affiliation(s)
- Brian E Sansbury
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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68
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Zuniga FA, Ormazabal V, Gutierrez N, Aguilera V, Radojkovic C, Veas C, Escudero C, Lamperti L, Aguayo C. Role of lectin-like oxidized low density lipoprotein-1 in fetoplacental vascular dysfunction in preeclampsia. BIOMED RESEARCH INTERNATIONAL 2014; 2014:353616. [PMID: 25110674 PMCID: PMC4109675 DOI: 10.1155/2014/353616] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 04/24/2014] [Indexed: 11/30/2022]
Abstract
The bioavailability of nitric oxide (NO) represents a key marker in vascular health. A decrease in NO induces a pathological condition denominated endothelial dysfunction, syndrome observed in different pathologies, such as obesity, diabetes, kidney disease, cardiovascular disease, and preeclampsia (PE). PE is one of the major risks for maternal death and fetal loss. Recent studies suggest that the placenta of pregnant women with PE express high levels of lectin-like oxidized LDL receptor-1 (LOX-1), which induces endothelial dysfunction by increasing reactive oxygen species (ROS) and decreasing intracellular NO. Besides LOX-1 activation induces changes in migration and apoptosis of syncytiotrophoblast cells. However, the role of this receptor in placental tissue is still unknown. In this review we will describes the physiological roles of LOX-1 in normal placenta development and the potential involvement of this receptor in the pathophysiology of PE.
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Affiliation(s)
- Felipe A. Zuniga
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Valeska Ormazabal
- Department of Basic Science, Faculty of Medicine, Universidad Católica de la Santísima Concepción, 4090541 Concepcion, Chile
| | - Nicolas Gutierrez
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Valeria Aguilera
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Claudia Radojkovic
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Carlos Veas
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Carlos Escudero
- Vascular Physiology Laboratory, Group of Investigation in Tumor Angiogenesis (GIANT), Group of Research and Innovation in Vascular Health (GRIVAS Health), Department of Basic Sciences, Faculty of Sciences, Universidad del Bío-Bío, 4081112 Chillán, Chile
| | - Liliana Lamperti
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Claudio Aguayo
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
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69
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Henriksen EJ. A radical concept on caveolae and endothelial dysfunction in coronary microvascular disease in diabetes. Diabetes 2014; 63:1200-2. [PMID: 24651806 DOI: 10.2337/db14-0057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Erik J Henriksen
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ
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70
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Song P, Zou MH. Redox regulation of endothelial cell fate. Cell Mol Life Sci 2014; 71:3219-39. [PMID: 24633153 DOI: 10.1007/s00018-014-1598-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/26/2014] [Accepted: 02/27/2014] [Indexed: 12/26/2022]
Abstract
Endothelial cells (ECs) are present throughout blood vessels and have variable roles in both physiological and pathological settings. EC fate is altered and regulated by several key factors in physiological or pathological conditions. Reactive nitrogen species and reactive oxygen species derived from NAD(P)H oxidases, mitochondria, or nitric oxide-producing enzymes are not only cytotoxic but also compose a signaling network in the redox system. The formation, actions, key molecular interactions, and physiological and pathological relevance of redox signals in ECs remain unclear. We review the identities, sources, and biological actions of oxidants and reductants produced during EC function or dysfunction. Further, we discuss how ECs shape key redox sensors and examine the biological functions, transcriptional responses, and post-translational modifications evoked by the redox system in ECs. We summarize recent findings regarding the mechanisms by which redox signals regulate the fate of ECs and address the outcome of altered EC fate in health and disease. Future studies will examine if the redox biology of ECs can be targeted in pathophysiological conditions.
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Affiliation(s)
- Ping Song
- Section of Molecular Medicine, Department of Internal Medicine, University of Oklahoma Health Sciences Center, 941 Stanton L Young Blvd., Oklahoma City, OK, 73104, USA,
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71
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Abstract
The prevalence of obesity has increased remarkably in the past four decades. Because obesity can promote the development of type 2 diabetes and cardiovascular disease, understanding the mechanisms that engender weight gain and discovering safe antiobesity therapies are of critical importance. In particular, the gaseous signaling molecule, nitric oxide (NO), appears to be a central factor regulating adiposity and systemic metabolism. Obese and diabetic states are characterized by a deficit in bioavailable NO, with such decreases commonly attributed to downregulation of endothelial NO synthase (eNOS), loss of eNOS activity, or quenching of NO by its reaction with oxygen radicals. Gain-of-function studies, in which vascular-derived NO has been increased pharmacologically or genetically, reveal remarkable actions of NO on body composition and systemic metabolism. This review addresses the metabolic actions of eNOS and the potential therapeutic utility of harnessing its antiobesogenic effects.
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Affiliation(s)
- Brian E Sansbury
- Diabetes and Obesity Center, Institute of Molecular Cardiology, Louisville, Kentucky, USA; Department of Physiology and Biophysics, Louisville, Kentucky, USA
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, Louisville, Kentucky, USA; Department of Physiology and Biophysics, Louisville, Kentucky, USA; Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, Kentucky, USA.
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72
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Richey JM. The vascular endothelium, a benign restrictive barrier? NO! Role of nitric oxide in regulating insulin action. Diabetes 2013; 62:4006-8. [PMID: 24264403 PMCID: PMC3837049 DOI: 10.2337/db13-1395] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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