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Rodríguez-Rivera NS, Barrera-Oviedo D. Exploring the Pathophysiology of ATP-Dependent Potassium Channels in Insulin Resistance. Int J Mol Sci 2024; 25:4079. [PMID: 38612888 PMCID: PMC11012456 DOI: 10.3390/ijms25074079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/15/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024] Open
Abstract
Ionic channels are present in eucaryotic plasma and intracellular membranes. They coordinate and control several functions. Potassium channels belong to the most diverse family of ionic channels that includes ATP-dependent potassium (KATP) channels in the potassium rectifier channel subfamily. These channels were initially described in heart muscle and then in other tissues such as pancreatic, skeletal muscle, brain, and vascular and non-vascular smooth muscle tissues. In pancreatic beta cells, KATP channels are primarily responsible for maintaining the membrane potential and for depolarization-mediated insulin release, and their decreased density and activity may be related to insulin resistance. KATP channels' relationship with insulin resistance is beginning to be explored in extra-pancreatic beta tissues like the skeletal muscle, where KATP channels are involved in insulin-dependent glucose recapture and their activation may lead to insulin resistance. In adipose tissues, KATP channels containing Kir6.2 protein subunits could be related to the increase in free fatty acids and insulin resistance; therefore, pathological processes that promote prolonged adipocyte KATP channel inhibition might lead to obesity due to insulin resistance. In the central nervous system, KATP channel activation can regulate peripheric glycemia and lead to brain insulin resistance, an early peripheral alteration that can lead to the development of pathologies such as obesity and Type 2 Diabetes Mellitus (T2DM). In this review, we aim to discuss the characteristics of KATP channels, their relationship with clinical disorders, and their mechanisms and potential associations with peripheral and central insulin resistance.
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Affiliation(s)
- Nidia Samara Rodríguez-Rivera
- Laboratorio de Farmacología y Bioquímica Clínica, Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico;
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2
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Russell-Jones D, Bawlchhim Z. Discovery of insulin 100 years on. Postgrad Med J 2023; 99:661-668. [PMID: 37389580 DOI: 10.1136/postgradmedj-2022-141651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/25/2022] [Indexed: 11/04/2022]
Abstract
The discovery of insulin 100 years ago ranks among the greatest medical achievements ever. This sparked a revolution of scientific discovery and therapeutic intervention to treat people suffering with diabetes. A light was shone for other areas of medicine to illuminate what was possible with detailed scientific endeavour. There followed a range of firsts leading to the current time in which we now know more about this peptide hormone than almost any other protein in existence. This has allowed therapeutic advancement from a positon of knowledge leading to stunning innovation. This innovation is likely to lead to more physiological insulin replacement reducing the disease burden to individuals and society as whole.
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Affiliation(s)
- David Russell-Jones
- CEDAR, Royal Surrey County Hospital, Guildford, UK
- Diabetes & Endocrinology, University of Surrey, Guildford, UK
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3
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Molinas AJR, Desmoulins LD, Davis RK, Gao H, Satou R, Derbenev AV, Zsombok A. High-Fat Diet Modulates the Excitability of Neurons within the Brain-Liver Pathway. Cells 2023; 12:1194. [PMID: 37190103 PMCID: PMC10137256 DOI: 10.3390/cells12081194] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/14/2023] [Accepted: 04/16/2023] [Indexed: 05/17/2023] Open
Abstract
Stimulation of hepatic sympathetic nerves increases glucose production and glycogenolysis. Activity of pre-sympathetic neurons in the paraventricular nucleus (PVN) of the hypothalamus and in the ventrolateral and ventromedial medulla (VLM/VMM) largely influence the sympathetic output. Increased activity of the sympathetic nervous system (SNS) plays a role in the development and progression of metabolic diseases; however, despite the importance of the central circuits, the excitability of pre-sympathetic liver-related neurons remains to be determined. Here, we tested the hypothesis that the activity of liver-related neurons in the PVN and VLM/VMM is altered in diet-induced obese mice, as well as their response to insulin. Patch-clamp recordings were conducted from liver-related PVN neurons, VLM-projecting PVN neurons, and pre-sympathetic liver-related neurons in the ventral brainstem. Our data demonstrate that the excitability of liver-related PVN neurons increased in high-fat diet (HFD)-fed mice compared to mice fed with control diet. Insulin receptor expression was detected in a population of liver-related neurons, and insulin suppressed the firing activity of liver-related PVN and pre-sympathetic VLM/VMM neurons in HFD mice; however, it did not affect VLM-projecting liver-related PVN neurons. These findings further suggest that HFD alters the excitability of pre-autonomic neurons as well as their response to insulin.
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Affiliation(s)
- Adrien J. R. Molinas
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA 70130, USA; (A.J.R.M.); (L.D.D.); (R.K.D.); (R.S.); (A.V.D.)
| | - Lucie D. Desmoulins
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA 70130, USA; (A.J.R.M.); (L.D.D.); (R.K.D.); (R.S.); (A.V.D.)
| | - Roslyn K. Davis
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA 70130, USA; (A.J.R.M.); (L.D.D.); (R.K.D.); (R.S.); (A.V.D.)
| | - Hong Gao
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA 70130, USA; (A.J.R.M.); (L.D.D.); (R.K.D.); (R.S.); (A.V.D.)
| | - Ryousuke Satou
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA 70130, USA; (A.J.R.M.); (L.D.D.); (R.K.D.); (R.S.); (A.V.D.)
| | - Andrei V. Derbenev
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA 70130, USA; (A.J.R.M.); (L.D.D.); (R.K.D.); (R.S.); (A.V.D.)
- Tulane Brain Institute, Tulane University, New Orleans, LA 70130, USA
| | - Andrea Zsombok
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA 70130, USA; (A.J.R.M.); (L.D.D.); (R.K.D.); (R.S.); (A.V.D.)
- Tulane Brain Institute, Tulane University, New Orleans, LA 70130, USA
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4
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Pekkarinen L, Kantonen T, Rebelos E, Latva-Rasku A, Dadson P, Karjalainen T, Bucci M, Kalliokoski K, Laitinen K, Houttu N, Kirjavainen AK, Rajander J, Rönnemaa T, Nummenmaa L, Nuutila P. Obesity risk is associated with brain glucose uptake and insulin resistance. Eur J Endocrinol 2022; 187:917-928. [PMID: 36288097 PMCID: PMC9782452 DOI: 10.1530/eje-22-0509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 10/26/2022] [Indexed: 01/09/2023]
Abstract
OBJECTIVE To investigate whether alterations in brain glucose uptake (BGU), insulin action in the brain-liver axis and whole-body insulin sensitivity occur in young adults in pre-obese state. METHODS Healthy males with either high risk (HR; n = 19) or low risk (LR; n = 22) for developing obesity were studied with [18F]fluoro-d-glucose ([18F]FDG)-positron emission tomography during hyperinsulinemic-euglycemic clamp. Obesity risk was assessed according to BMI, physical activity and parental overweight/obesity and type 2 diabetes. Brain, skeletal muscle, brown adipose tissue (BAT), visceral adipose tissue (VAT) and abdominal and femoral s.c. adipose tissue (SAT) glucose uptake (GU) rates were measured. Endogenous glucose production (EGP) was calculated by subtracting the exogenous glucose infusion rate from the rate of disappearance of [18F]FDG. BGU was analyzed using statistical parametric mapping, and peripheral tissue activity was determined using Carimas Software imaging processing platform. RESULTS BGU was higher in the HR vs LR group and correlated inversely with whole-body insulin sensitivity (M value) in the HR group but not in the LR group. Insulin-suppressed EGP did not differ between the groups but correlated positively with BGU in the whole population, and the correlation was driven by the HR group. Skeletal muscle, BAT, VAT, abdominal and femoral SAT GU were lower in the HR group as compared to the LR group. Muscle GU correlated negatively with BGU in the HR group but not in the LR group. CONCLUSION Increased BGU, alterations in insulin action in the brain-liver axis and decreased whole-body insulin sensitivity occur early in pre-obese state.
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Affiliation(s)
- Laura Pekkarinen
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Endocrinology, Turku University Hospital, Turku, Finland
| | - Tatu Kantonen
- Turku PET Centre, University of Turku, Turku, Finland
- Clinical Neurosciences, Turku University Hospital, Turku, Finland
| | - Eleni Rebelos
- Turku PET Centre, University of Turku, Turku, Finland
| | | | - Prince Dadson
- Turku PET Centre, University of Turku, Turku, Finland
| | | | - Marco Bucci
- Turku PET Centre, University of Turku, Turku, Finland
- Turku PET Centre, Åbo Akademi University, Turku, Finland
| | | | - Kirsi Laitinen
- Institute of Biomedicine, Research Centre for Integrative Physiology and Pharmacology, University of Turku, Turku, Finland
| | - Noora Houttu
- Institute of Biomedicine, Research Centre for Integrative Physiology and Pharmacology, University of Turku, Turku, Finland
| | | | - Johan Rajander
- Turku PET Centre, Åbo Akademi University, Turku, Finland
| | - Tapani Rönnemaa
- Department of Endocrinology, Turku University Hospital, Turku, Finland
- Department of Medicine, University of Turku, Turku, Finland
| | - Lauri Nummenmaa
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Psychology, University of Turku, Turku, Finland
| | - Pirjo Nuutila
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Endocrinology, Turku University Hospital, Turku, Finland
- Correspondence should be addressed to P Nuutila;
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Campbell IH, Campbell H, Smith DJ. Insulin signaling as a therapeutic mechanism of lithium in bipolar disorder. Transl Psychiatry 2022; 12:350. [PMID: 36038539 PMCID: PMC9424309 DOI: 10.1038/s41398-022-02122-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/09/2022] [Accepted: 08/16/2022] [Indexed: 11/15/2022] Open
Abstract
In this paper, we propose that lithium may exert its therapeutic effect in bipolar disorder by acting on insulin signaling pathways. Specifically, we assess the importance of the phosphatidylinositol 3-kinase/Protein Kinase B (PI3K/Akt) insulin signaling pathway and we assess how the action of lithium on both glycogen synthase kinase-3 (GSK3) and the phosphatidylinositol cycle may lead to mood stabilization mediated by PI3K/Akt insulin signaling. We also highlight evidence that several other actions of lithium (including effects on Akt, Protein kinase C (PKC), and sodium myo-inositol transporters) are putative mediators of insulin signaling. This novel mode of action of lithium is consistent with an emerging consensus that energy dysregulation represents a core deficit in bipolar disorder. It may also provide context for the significant co-morbidity between bipolar disorder, type 2 diabetes, and other forms of metabolic illness characterized by impaired glucose metabolism. It is suggested that developments in assessing neuronal insulin signaling using extracellular vesicles would allow for this hypothesis to be tested in bipolar disorder patients.
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Affiliation(s)
- Iain H. Campbell
- grid.4305.20000 0004 1936 7988Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Harry Campbell
- grid.4305.20000 0004 1936 7988Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Daniel J. Smith
- grid.4305.20000 0004 1936 7988Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
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Lin KJ, Wang TJ, Chen SD, Lin KL, Liou CW, Lan MY, Chuang YC, Chuang JH, Wang PW, Lee JJ, Wang FS, Lin HY, Lin TK. Two Birds One Stone: The Neuroprotective Effect of Antidiabetic Agents on Parkinson Disease-Focus on Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors. Antioxidants (Basel) 2021; 10:antiox10121935. [PMID: 34943038 PMCID: PMC8750793 DOI: 10.3390/antiox10121935] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 12/13/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease affecting more than 1% of the population over 65 years old. The etiology of the disease is unknown and there are only symptomatic managements available with no known disease-modifying treatment. Aging, genes, and environmental factors contribute to PD development and key players involved in the pathophysiology of the disease include oxidative stress, mitochondrial dysfunction, autophagic-lysosomal imbalance, and neuroinflammation. Recent epidemiology studies have shown that type-2 diabetes (T2DM) not only increased the risk for PD, but also is associated with PD clinical severity. A higher rate of insulin resistance has been reported in PD patients and is suggested to be a pathologic driver in this disease. Oral diabetic drugs including sodium-glucose cotransporter 2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and dipeptidyl peptidase-4 (DPP-4) inhibitors have been shown to provide neuroprotective effects in both PD patients and experimental models; additionally, antidiabetic drugs have been demonstrated to lower incidence rates of PD in DM patients. Among these, the most recently developed drugs, SGLT2 inhibitors may provide neuroprotective effects through improving mitochondrial function and antioxidative effects. In this article, we will discuss the involvement of mitochondrial-related oxidative stress in the development of PD and potential benefits provided by antidiabetic agents especially focusing on sglt2 inhibitors.
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Affiliation(s)
- Kai-Jung Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Family Medicine, National Taiwan University Hospital, Taipei 100225, Taiwan
| | - Tzu-Jou Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Pediatric, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Shang-Der Chen
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Center of Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Kai-Lieh Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Chia-Wei Liou
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Center of Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Min-Yu Lan
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Center of Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Yao-Chung Chuang
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Center of Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Jiin-Haur Chuang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Pediatric Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Pei-Wen Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Metabolism, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Jong-Jer Lee
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Feng-Sheng Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan
| | - Hung-Yu Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Research Assistant Center, Show Chwan Memorial Hospital, Changhua 500, Taiwan
| | - Tsu-Kung Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
- Center of Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
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Abstract
There has been 100 years of research detailing the role of insulin in glucose, protein and free fatty acid metabolism. We explore the learnings though evolution and changes in management with an understanding of how it has impacted the care of people with diabetes. The discrimination endured is described and recent advances to empower and counter this are highlighted.
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Affiliation(s)
- David Russell‐Jones
- Royal Surrey County HospitalGuildfordSurreyUK
- University of SurreyGuildfordSurreyUK
| | - Roselle Herring
- Royal Surrey County HospitalGuildfordSurreyUK
- University of SurreyGuildfordSurreyUK
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8
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Ozgen Saydam B, Yildiz BO. Polycystic Ovary Syndrome and Brain: An Update on Structural and Functional Studies. J Clin Endocrinol Metab 2021; 106:e430-e441. [PMID: 33205212 DOI: 10.1210/clinem/dgaa843] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Indexed: 12/25/2022]
Abstract
CONTEXT Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of women in reproductive age and is associated with reproductive, endocrine, metabolic, cardiovascular, and psychological outcomes. All these disorders are thought to be affected by central mechanisms which could be a major contributor in pathogenesis of PCOS. EVIDENCE ACQUISITION This mini-review discusses the relevance of central nervous system imaging modalities in understanding the neuroendocrine origins of PCOS as well as their relevance to understanding its comorbidities. EVIDENCE SYNTHESIS Current data suggest that central nervous system plays a key role in development of PCOS. Decreased global and regional brain volumes and altered white matter microstructure in women with PCOS is shown by structural imaging modalities. Functional studies show diminished reward response in corticolimbic areas, brain glucose hypometabolism, and greater opioid receptor availability in reward-related regions in insulin-resistant patients with PCOS. These structural and functional disturbances are associated with nonhomeostatic eating, diminished appetitive responses, as well as cognitive dysfunction and mood disorders in women with PCOS. CONCLUSION Structural and functional brain imaging is an emerging modality in understanding pathophysiology of metabolic disorders such as diabetes and obesity as well as PCOS. Neuroimaging can help researchers and clinicians for better understanding the pathophysiology of PCOS and related comorbidities as well as better phenotyping PCOS.
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Affiliation(s)
- Basak Ozgen Saydam
- Division of Endocrinology and Metabolism, Dokuz Eylul University School of Medicine, İzmir, Turkey
| | - Bulent Okan Yildiz
- Division of Endocrinology and Metabolism, Hacettepe University School of Medicine, Ankara, Turkey
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9
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Chowen JA, Frago LM, Fernández-Alfonso MS. Physiological and pathophysiological roles of hypothalamic astrocytes in metabolism. J Neuroendocrinol 2019; 31:e12671. [PMID: 30561077 DOI: 10.1111/jne.12671] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/27/2018] [Accepted: 12/11/2018] [Indexed: 12/26/2022]
Abstract
The role of glial cells, including astrocytes, in metabolic control has received increasing attention in recent years. Although the original interest in these macroglial cells was a result of astrogliosis being observed in the hypothalamus of diet-induced obese subjects, studies have also focused on how they participate in the physiological control of appetite and energy expenditure. Astrocytes express receptors for numerous hormones, growth factors and neuropeptides. Some functions of astrocytes include transport of nutrients and hormones from the circulation to the brain, storage of glycogen, participation in glucose sensing, synaptic plasticity, uptake and metabolism of neurotransmitters, release of substances to modify neurotransmission, and cytokine production, amongst others. In the hypothalamus, these physiological glial functions impact on neuronal circuits that control systemic metabolism to modify their outputs. The initial response of astrocytes to poor dietary habits and obesity involves activation of neuroprotective mechanisms but, with chronic exposure to these situations, hypothalamic astrocytes participate in the development of some of the damaging secondary effects. The present review discusses not only some of the physiological functions of hypothalamic astrocytes in metabolism, but also their role in the secondary complications of obesity, such as insulin resistance and cardiovascular affectations.
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Affiliation(s)
- Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- CIBEROBN (Centro de Investigación Biomédica en Red sobre Fisiopatología de la Obesidad y Nutrición), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- CIBEROBN (Centro de Investigación Biomédica en Red sobre Fisiopatología de la Obesidad y Nutrición), Instituto de Salud Carlos III, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Soledad Fernández-Alfonso
- Instituto Pluridisciplinar UCM y Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
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10
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Honkala SM, Johansson J, Motiani KK, Eskelinen JJ, Virtanen KA, Löyttyniemi E, Knuuti J, Nuutila P, Kalliokoski KK, Hannukainen JC. Short-term interval training alters brain glucose metabolism in subjects with insulin resistance. J Cereb Blood Flow Metab 2018; 38:1828-1838. [PMID: 28959911 PMCID: PMC6168908 DOI: 10.1177/0271678x17734998] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Brain insulin-stimulated glucose uptake (GU) is increased in obese and insulin resistant subjects but normalizes after weight loss along with improved whole-body insulin sensitivity. Our aim was to study whether short-term exercise training (moderate intensity continuous training (MICT) or sprint interval training (SIT)) alters substrates for brain energy metabolism in insulin resistance. Sedentary subjects ( n = 21, BMI 23.7-34.3 kg/m2, age 43-55 y) with insulin resistance were randomized into MICT ( n = 11, intensity≥60% of VO2peak) or SIT ( n = 10, all-out) groups for a two-week training intervention. Brain GU during insulin stimulation and fasting brain free fatty acid uptake (FAU) was measured using PET. At baseline, brain GU was positively associated with the fasting insulin level and negatively with the whole-body insulin sensitivity. The whole-body insulin sensitivity improved with both training modes (20%, p = 0.007), while only SIT led to an increase in aerobic capacity (5%, p = 0.03). SIT also reduced insulin-stimulated brain GU both in global cortical grey matter uptake (12%, p = 0.03) and in specific regions ( p < 0.05, all areas except the occipital cortex), whereas no changes were observed after MICT. Brain FAU remained unchanged after the training in both groups. These findings show that short-term SIT effectively decreases insulin-stimulated brain GU in sedentary subjects with insulin resistance.
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Affiliation(s)
| | | | | | | | | | | | - Juhani Knuuti
- 3 Turku PET Centre, Åbo Akademi University, Turku, Finland.,4 Turku PET Centre, Turku University Hospital, Turku, Finland
| | - Pirjo Nuutila
- 1 Turku PET Centre, University of Turku, Turku, Finland.,4 Turku PET Centre, Turku University Hospital, Turku, Finland
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Grosu C, Oprescu AC, Niţă O, Bild W. Insulin and the Brain. ROMANIAN JOURNAL OF DIABETES NUTRITION AND METABOLIC DISEASES 2017. [DOI: 10.1515/rjdnmd-2017-0044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abstract
The brain represents an important site for the action of insulin. Besides the traditionally known importance in glucoregulation, insulin has significant neurotrophic properties and influences the brain activity: insulin influences eating behavior, regulates the storage of energy and several aspects concerning memory and knowledge. Insulin resistance and hyperinsulinism could be associated with brain aging, vascular and metabolic pathologies. Elucidating the pathways and metabolism of brain insulin could have a major impact on future targeted therapies.
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Affiliation(s)
- Cristina Grosu
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Neurology , Clinical Rehabilitation Hospital Iasi , Romania
| | - Andrei Cătălin Oprescu
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Diabetes, Nutrition and Metabolic Diseases , “Sf Spiridon” Clinical Emergency Hospital Iasi , Romania
| | - Otilia Niţă
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Diabetes, Nutrition and Metabolic Diseases , “Sf Spiridon” Clinical Emergency Hospital Iasi , Romania
| | - Walther Bild
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Normal and Pathologic Physiology
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12
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Romualdi D, Immediata V, De Cicco S, Tagliaferri V, Lanzone A. Neuroendocrine Regulation of Food Intake in Polycystic Ovary Syndrome. Reprod Sci 2017; 25:644-653. [PMID: 28874103 DOI: 10.1177/1933719117728803] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Several peripheral and central signals are involved in the sophisticated regulation of food intake. Women with polycystic ovary syndrome (PCOS) are prone to consume a diet higher in saturated fat and foods with high glycemic index and show impaired appetite regulation and measures of satiety. As a consequence, obesity, mostly of the central type, is prevalent in the syndrome and worsens the endocrine and metabolic profile of the affected patients. This review article briefly analyzes the current knowledge about the neuroendocrine mechanisms underlying the interplay between feeding behavior, obesity, and reproductive abnormalities in PCOS.
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Affiliation(s)
- Daniela Romualdi
- 1 Department of Obstetrics and Gynaecology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Valentina Immediata
- 1 Department of Obstetrics and Gynaecology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Simona De Cicco
- 1 Department of Obstetrics and Gynaecology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Valeria Tagliaferri
- 1 Department of Obstetrics and Gynaecology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Antonio Lanzone
- 1 Department of Obstetrics and Gynaecology, Università Cattolica del Sacro Cuore, Rome, Italy
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Liu L, Xu S, Wang X, Jiao H, Lin H. Peripheral Insulin Doesn't Alter Appetite of Broiler Chicks. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2016; 29:1294-9. [PMID: 26954230 PMCID: PMC5003990 DOI: 10.5713/ajas.15.0674] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 12/20/2015] [Accepted: 12/28/2015] [Indexed: 12/21/2022]
Abstract
An experiment was conducted to investigate the effect of peripheral insulin treatment on appetite in chicks. Six-d-age chicks with ad libitum feeding or fasting for 3 h before injection received a subcutaneous injection of 0, 1, 3, 5, 10, or 20 IU of insulin or vehicle (saline). The results showed peripheral insulin treatment (1 to 20 IU) did not alter significantly the feed intake in chicks under either ad libitum feeding or fasting conditions within 4 h (p>0.05). Compared with the control, plasma glucose concentration was significantly decreased after insulin treatment of 3, 5, 10, and 20 IU for 4 h in chicks with ad libitum feeding (p<0.05). In fasted chicks, 10 and 20 IU insulin treatments significantly decreased the plasma glucose level for 4 h (p<0.05). Peripheral insulin treatment of 10 IU for 2 or 4 h did not significantly affect the hypothalamic genes expression of neuropeptide Y, proopiomelanocortin, corticotropin-releasing factor and insulin receptors (p>0.05). All results suggest peripheral administration of insulin has no effect on appetite in chicks.
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Affiliation(s)
- Lei Liu
- Department of Animal Science, Shandong Agricultural University, Shandong Key Lab for Animal Biotechnology and Disease Control, Taian, Shandong 271018, China
| | - Shaohua Xu
- Department of Animal Science, Shandong Agricultural University, Shandong Key Lab for Animal Biotechnology and Disease Control, Taian, Shandong 271018, China
| | - Xiaojuan Wang
- Department of Animal Science, Shandong Agricultural University, Shandong Key Lab for Animal Biotechnology and Disease Control, Taian, Shandong 271018, China
| | - Hongchao Jiao
- Department of Animal Science, Shandong Agricultural University, Shandong Key Lab for Animal Biotechnology and Disease Control, Taian, Shandong 271018, China
| | - Hai Lin
- Department of Animal Science, Shandong Agricultural University, Shandong Key Lab for Animal Biotechnology and Disease Control, Taian, Shandong 271018, China
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14
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Cornell S. Continual evolution of type 2 diabetes: an update on pathophysiology and emerging treatment options. Ther Clin Risk Manag 2015; 11:621-32. [PMID: 25931824 PMCID: PMC4404882 DOI: 10.2147/tcrm.s67387] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Diabetes is a complex and progressive disease that has a major societal and economic impact. The most common form of diabetes, type 2 diabetes mellitus (T2DM), is a multifactorial disease, the pathophysiology of which involves not only the pancreas but also the liver, skeletal muscle, adipose tissue, gastrointestinal tract, brain, and kidney. Novel therapies with mechanisms of action that are different from most existing drugs are emerging. One such class consists of compounds that inhibit renal sodium-glucose cotransporter 2, which is responsible for the bulk of glucose reabsorption by the kidneys. This new class of compounds improves glycemic control independently of insulin and promotes weight reduction, providing an additional tool to treat patients with T2DM. This review discusses the underlying pathophysiology of T2DM, clinical guidelines, and available and emerging treatment options, with particular emphasis on sodium-glucose cotransporter 2 inhibitors.
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Affiliation(s)
- Susan Cornell
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, USA
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15
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Jastreboff AM, Lacadie C, Seo D, Kubat J, Van Name MA, Giannini C, Savoye M, Constable RT, Sherwin RS, Caprio S, Sinha R. Leptin is associated with exaggerated brain reward and emotion responses to food images in adolescent obesity. Diabetes Care 2014; 37:3061-8. [PMID: 25139883 PMCID: PMC4207200 DOI: 10.2337/dc14-0525] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE In the U.S., an astonishing 12.5 million children and adolescents are now obese, predisposing 17% of our nation's youth to metabolic complications of obesity, such as type 2 diabetes (T2D). Adolescent obesity has tripled over the last three decades in the setting of food advertising directed at children. Obese adults exhibit increased brain responses to food images in motivation-reward pathways. These neural alterations may be attributed to obesity-related metabolic changes, which promote food craving and high-calorie food (HCF) consumption. It is not known whether these metabolic changes affect neural responses in the adolescent brain during a crucial period for establishing healthy eating behaviors. RESEARCH DESIGN AND METHODS Twenty-five obese (BMI 34.4 kg/m2, age 15.7 years) and fifteen lean (BMI 20.96 kg/m2, age 15.5 years) adolescents underwent functional MRI during exposure to HCF, low-calorie food (LCF), and nonfood (NF) visual stimuli 2 h after isocaloric meal consumption. RESULTS Brain responses to HCF relative to NF cues increased in obese versus lean adolescents in striatal-limbic regions (i.e., putamen/caudate, insula, amygdala) (P < 0.05, family-wise error [FWE]), involved in motivation-reward and emotion processing. Higher endogenous leptin levels correlated with increased neural activation to HCF images in all subjects (P < 0.05, FWE). CONCLUSIONS This significant association between higher circulating leptin and hyperresponsiveness of brain motivation-reward regions to HCF images suggests that dysfunctional leptin signaling may contribute to the risk of overconsumption of these foods, thus further predisposing adolescents to the development of obesity and T2D.
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Affiliation(s)
- Ania M Jastreboff
- Division of Endocrinology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Cheryl Lacadie
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT
| | - Dongju Seo
- Department of Psychiatry, Yale University School of Medicine, Yale Stress Center, New Haven, CT
| | - Jessica Kubat
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Michelle A Van Name
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Cosimo Giannini
- Department of Pediatric, University of Chieti, Chieti, Italy
| | - Mary Savoye
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - R Todd Constable
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT
| | - Robert S Sherwin
- Division of Endocrinology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT
| | - Sonia Caprio
- Division of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Rajita Sinha
- Department of Psychiatry, Yale University School of Medicine, Yale Stress Center, New Haven, CT Department of Neurobiology, Yale University School of Medicine, New Haven, CT Child Study Center, Yale University School of Medicine, New Haven, CT
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16
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Feng X, Scott A, Wang Y, Wang L, Zhao Y, Doerner S, Satake M, Croniger CM, Wang Z. PTPRT regulates high-fat diet-induced obesity and insulin resistance. PLoS One 2014; 9:e100783. [PMID: 24949727 PMCID: PMC4065109 DOI: 10.1371/journal.pone.0100783] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/28/2014] [Indexed: 02/03/2023] Open
Abstract
Obesity is a risk factor for many human diseases. However, the underlying molecular causes of obesity are not well understood. Here, we report that protein tyrosine phosphatase receptor T (PTPRT) knockout mice are resistant to high-fat diet-induced obesity. Those mice avoid many deleterious side effects of high-fat diet-induced obesity, displaying improved peripheral insulin sensitivity, lower blood glucose and insulin levels. Compared to wild type littermates, PTPRT knockout mice show reduced food intake. Consistently, STAT3 phosphorylation is up-regulated in the hypothalamus of PTPRT knockout mice. These studies implicate PTPRT-modulated STAT3 signaling in the regulation of high-fat diet-induced obesity.
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Affiliation(s)
- Xiujing Feng
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Anthony Scott
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yong Wang
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Lan Wang
- Department of Nutrition, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yiqing Zhao
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Stephanie Doerner
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Masanobu Satake
- Department of Molecular Immunology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Colleen M. Croniger
- Department of Nutrition, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Zhenghe Wang
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
- Genomic Medicine Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
- * E-mail:
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17
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Depuydt G, Xie F, Petyuk VA, Smolders A, Brewer HM, Camp DG, Smith RD, Braeckman BP. LC-MS proteomics analysis of the insulin/IGF-1-deficient Caenorhabditis elegans daf-2(e1370) mutant reveals extensive restructuring of intermediary metabolism. J Proteome Res 2014; 13:1938-56. [PMID: 24555535 PMCID: PMC3993954 DOI: 10.1021/pr401081b] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Indexed: 12/11/2022]
Abstract
The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity, and metabolism in Caenorhabditis elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including the expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass spectrometry (LC-MS)-based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2);daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the upregulation of many core intermediary metabolic pathways. These include glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complexes I, II, III, and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative of spatiotemporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. This restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves and possibly also shunting metabolites through alternative energy-generating pathways to sustain longevity.
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Affiliation(s)
- Geert Depuydt
- Biology
Department, Ghent University, Proeftuinstraat 86 N1, B-9000 Ghent, Belgium
| | - Fang Xie
- Biological
Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Vladislav A. Petyuk
- Biological
Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Arne Smolders
- Biology
Department, Ghent University, Proeftuinstraat 86 N1, B-9000 Ghent, Belgium
| | - Heather M. Brewer
- Biological
Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - David G. Camp
- Biological
Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Richard D. Smith
- Biological
Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Bart P. Braeckman
- Biology
Department, Ghent University, Proeftuinstraat 86 N1, B-9000 Ghent, Belgium
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18
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Van Vugt DA, Krzemien A, Alsaadi H, Frank TC, Reid RL. Glucose-induced inhibition of the appetitive brain response to visual food cues in polycystic ovary syndrome patients. Brain Res 2014; 1558:44-56. [PMID: 24583185 DOI: 10.1016/j.brainres.2014.02.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/21/2014] [Accepted: 02/19/2014] [Indexed: 11/29/2022]
Abstract
We postulate that insulin regulation of food intake is compromised when insulin resistance is present. In order to investigate the effect of insulin sensitivity on appetitive brain responses, we conducted functional magnetic resonance imaging studies in a group of women diagnosed with polycystic ovary syndrome (PCOS) in which insulin sensitivity ranged from normal to resistant. Subjects (n=19) were imaged while viewing pictures of high calorie (HC) foods and low calorie (LC) foods after ingesting either 75 g glucose or an equivalent volume of water. The insulin sensitive group showed reduced blood oxygen level dependent (BOLD) signal in response to food pictures following glucose ingestion in numerous corticolimbic brain regions, whereas the insulin resistant group did not. There was a significant interaction between insulin sensitivity (sensitive vs resistant) and condition (water vs glucose). The largest clusters identified included the left insula, bilateral limbic/parahippocampal gyrus/culmen/midbrain, bilateral limbic lobe/precuneus, and left superior/mid temporal gyrus/parietal for HC and LC stimuli combined, the left parahippocampal gyrus/fusiform/pulvinar/midbrain for HC pictures, and the left superior/mid temporal gyrus/parietal and middle/inferior frontal gyrus/orbitofrontal cortex for LC pictures. Furthermore, BOLD signal in the anterior cingulate, medial frontal gyrus, posterior cingulate/precuneus, and parietal cortex during a glucose challenge correlated negatively with insulin sensitivity. We conclude the PCOS women with insulin resistance have an impaired brain response to a glucose challenge. The inability of postprandial hyperinsulinemia to inhibit brain responsiveness to food cues in insulin resistant subjects may lead to greater non-homeostatic eating.
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Affiliation(s)
- Dean A Van Vugt
- Department of Obstetrics & Gynaecology, Queen׳s University, Kingston, Canada; Department of Biomedical and Molecular Sciences, Queen׳s University, Kingston, Canada.
| | - Alicja Krzemien
- Department of Obstetrics & Gynaecology, Queen׳s University, Kingston, Canada
| | - Hanin Alsaadi
- Department of Biomedical and Molecular Sciences, Queen׳s University, Kingston, Canada
| | - Tamar C Frank
- Department of Biomedical and Molecular Sciences, Queen׳s University, Kingston, Canada
| | - Robert L Reid
- Department of Obstetrics & Gynaecology, Queen׳s University, Kingston, Canada
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19
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Herring R, Jones RH, Russell-Jones DL. Hepatoselectivity and the evolution of insulin. Diabetes Obes Metab 2014; 16:1-8. [PMID: 23679086 DOI: 10.1111/dom.12117] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 04/09/2013] [Accepted: 04/15/2013] [Indexed: 12/31/2022]
Abstract
In spite of major developments in insulin production, purification, pharmaceutical formulation and methods of delivery, problems remain both in the day to day management of insulin-treated diabetes and with regard to its long-term complications. The risks of hypoglycaemia and weight gain are major concerns particularly for the patient, and the persistence of microvascular and premature macrovascular complications as the main causes of morbidity and mortality in both type 1 and type 2 diabetes is a constant reminder that our therapeutic and management strategies are inadequate. One clear and striking difference between currently available insulin treatments and normal physiology is the relative difference in exposure to insulin of the liver versus peripheral tissues. Hepatoselective insulin analogues have the potential to restore the normal hepatic to peripheral gradient in insulin action. Here, we discuss the possible therapeutic potential that such analogues may have over currently available insulin preparations. These benefits could include a lower risk of hypoglycaemia, less weight gain and a potential reduction in microvascular and macrovascular complications. We explore the evolution of insulin with hepatoselectivity in mind and possible strategies to create hepatoselective insulins.
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Affiliation(s)
- R Herring
- Centre for Endocrinology, Diabetes and Research, Royal Surrey County Hospital, Guildford, UK
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20
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Tuulari JJ, Karlsson HK, Hirvonen J, Hannukainen JC, Bucci M, Helmiö M, Ovaska J, Soinio M, Salminen P, Savisto N, Nummenmaa L, Nuutila P. Weight loss after bariatric surgery reverses insulin-induced increases in brain glucose metabolism of the morbidly obese. Diabetes 2013; 62:2747-51. [PMID: 23493575 PMCID: PMC3717871 DOI: 10.2337/db12-1460] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Obesity and insulin resistance are associated with altered brain glucose metabolism. Here, we studied brain glucose metabolism in 22 morbidly obese patients before and 6 months after bariatric surgery. Seven healthy subjects served as control subjects. Brain glucose metabolism was measured twice per imaging session: with and without insulin stimulation (hyperinsulinemic-euglycemic clamp) using [18F]fluorodeoxyglucose scanning. We found that during fasting, brain glucose metabolism was not different between groups. However, the hyperinsulinemic clamp increased brain glucose metabolism in a widespread manner in the obese but not control subjects, and brain glucose metabolism was significantly higher during clamp in obese than in control subjects. After follow-up, 6 months postoperatively, the increase in glucose metabolism was no longer observed, and this attenuation was coupled with improved peripheral insulin sensitivity after weight loss. We conclude that obesity is associated with increased insulin-stimulated glucose metabolism in the brain and that this abnormality can be reversed by bariatric surgery.
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Affiliation(s)
- Jetro J. Tuulari
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Henry K. Karlsson
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Jussi Hirvonen
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
- Department of Radiology, University of Turku and Turku University Hospital, Turku, Finland
| | - Jarna C. Hannukainen
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Marco Bucci
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Mika Helmiö
- Department of Surgery, University of Turku and Turku University Hospital, Turku, Finland
| | - Jari Ovaska
- Department of Surgery, University of Turku and Turku University Hospital, Turku, Finland
| | - Minna Soinio
- Department of Medicine, Turku University Hospital, Turku, Finland
| | - Paulina Salminen
- Department of Surgery, University of Turku and Turku University Hospital, Turku, Finland
| | - Nina Savisto
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Lauri Nummenmaa
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
- Department of Biomedical Engineering and Computational Science, School of Science, Aalto University, Espoo, Finland
- Brain Research Unit, O.V. Lounasmaa Laboratory, School of Science, Aalto University, Espoo, Finland
| | - Pirjo Nuutila
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
- Department of Medicine, Turku University Hospital, Turku, Finland
- Corresponding author: Pirjo Nuutila,
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21
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Cornell S, Dorsey VJ. Diabetes pharmacotherapy in 2012: considerations in medication selection. Postgrad Med 2012; 124:84-94. [PMID: 22913897 DOI: 10.3810/pgm.2012.07.2571] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Diabetes is one of the most costly and burdensome chronic diseases, and its therapy and management have become increasingly complex. The incidence of type 2 diabetes mellitus (T2DM), a multiorgan disorder, is increasing at an epidemic rate in the United States and worldwide. Despite numerous scientific and medical advances, less than half of the population with T2DM has achieved the American Diabetes Association-recommended glycated hemoglobin level goal of < 7%, which is necessary to optimally manage the disease to prevent and minimize complications. There are many patient- and clinician-determined barriers that hinder patients from achieving target blood glucose levels. Therefore, it is imperative for health care professionals who treat patients with T2DM (and those at risk for developing T2DM) to have an enhanced knowledge base of the current pathophysiology, treatment options, and clinical guidelines for T2DM and its related conditions.
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Affiliation(s)
- Susan Cornell
- Midwestern University Chicago College of Pharmacy, Downers Grove, IL 60515, USA.
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22
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Abstract
Despite the known benefits of a healthy lifestyle, many individuals find it hard to maintain such a lifestyle in our modern world, which facilitates sedentary behavior and overeating. As a consequence, the prevalence of type 2 diabetes mellitus is predicted to increase dramatically over the coming years. Will developments in treatments be able to counteract the resulting impact on morbidity and mortality? The various lines of research can be grouped into three main categories: technological, biological, and pharmacological. Technological solutions are focused on the delivery of insulin and glucagon via an artificial pancreas, and components of the system are already in use, suggesting this option may well be available within the next 10 years. Of the biological solutions, pancreas transplants seem unlikely to be used widely, and islet cell transplants have also been hampered by a lack of appropriate donor tissue and graft survival after transplant. However, significant progress has been made in these areas, and additional research suggests manipulating other cell types to replace beta cells may be a viable option in the longer term. The last category, pharmacological research, appears the most promising for significantly reducing the burden of type 2 diabetes mellitus. In recent years, research has concentrated on reducing blood glucose, and the increasing pace of research has been reflected in a growing number of antidiabetic agents. In the past few years, studies of the complementary approach of protecting cells from the damaging effects of high blood glucose have also been reported, as has research into the control of energy intake and energy expenditure. Evidence from studies of dietary restriction and bariatric surgery suggests it may be possible to reset metabolism to effectively cure diabetes, and research into pharmacological agents that could selectively restore energy balance is currently the most exciting prospect for future treatments for people with type 2 diabetes mellitus.
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Affiliation(s)
- Mansur Shomali
- The Diabetes and Endocrine Center, MedStar Union Memorial Hospital, 201 East University Parkway, 33rd Street Professional Building, Suite 501, Baltimore, MD 21218, USA
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23
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Heni M, Kullmann S, Ketterer C, Guthoff M, Linder K, Wagner R, Stingl KT, Veit R, Staiger H, Häring HU, Preissl H, Fritsche A. Nasal insulin changes peripheral insulin sensitivity simultaneously with altered activity in homeostatic and reward-related human brain regions. Diabetologia 2012; 55:1773-82. [PMID: 22434537 DOI: 10.1007/s00125-012-2528-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 02/15/2012] [Indexed: 12/25/2022]
Abstract
AIMS/HYPOTHESIS Impaired insulin sensitivity is a major factor leading to type 2 diabetes. Animal studies suggest that the brain is involved in the regulation of insulin sensitivity. We investigated whether insulin action in the human brain regulates peripheral insulin sensitivity and examined which brain areas are involved. METHODS Insulin and placebo were given intranasally. Plasma glucose, insulin and C-peptide were measured in 103 participants at 0, 30 and 60 min. A subgroup (n = 12) was also studied with functional MRI, and blood sampling at 0, 30 and 120 min. For each time-point, the HOMA of insulin resistance (HOMA-IR) was calculated as an inverse estimate of peripheral insulin sensitivity. RESULTS Plasma insulin increased and subsequently decreased. This excursion was accompanied by slightly decreased plasma glucose, resulting in an initially increased HOMA-IR. At 1 h after insulin spray, the HOMA-IR subsequently decreased and remained lower up to 120 min. An increase in hypothalamic activity was observed, which correlated with the increased HOMA-IR at 30 min post-spray. Activity in the putamen, right insula and orbitofrontal cortex correlated with the decreased HOMA-IR at 120 min post-spray. CONCLUSIONS/INTERPRETATION Central insulin action in specific brain areas, including the hypothalamus, may time-dependently regulate peripheral insulin sensitivity. This introduces a potential novel mechanism for the regulation of peripheral insulin sensitivity and underlines the importance of cerebral insulin action for the whole organism.
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Affiliation(s)
- M Heni
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, Eberhard Karls University Tübingen, Otfried-Müller-Str 10, 72076 Tübingen, Germany
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24
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The role of the central nervous system in glucose homeostasis. ROMANIAN JOURNAL OF DIABETES NUTRITION AND METABOLIC DISEASES 2012. [DOI: 10.2478/v10255-012-0025-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract Central nervous system, mainly the hypothalamus and the brainstem are importantkeys in glucose homeostasis. Not only do they use glucose as primary fuel for theirfunctioning but they are part of intricate neuronal circuits involved in glucose uptakeand production as was first shown by Claude Bernard. Moreoverelectrophysiological analysis of hypothalamus revealed the existence of glucosensingneurons whose firing rates are controlled by glucose extracellular level. Furtherinformation was obtained regarding the importance of leptin, insulin and free fattyacids as afferent signals received by these neural structures. As for the main efferentpathways, autonomic system is the one connecting CNS with the effector organs (theliver, the pancreas and the adrenal glands).
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25
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Paranjape SA, Chan O, Zhu W, Horblitt AM, Grillo CA, Wilson S, Reagan L, Sherwin RS. Chronic reduction of insulin receptors in the ventromedial hypothalamus produces glucose intolerance and islet dysfunction in the absence of weight gain. Am J Physiol Endocrinol Metab 2011; 301:E978-83. [PMID: 21828334 PMCID: PMC3774165 DOI: 10.1152/ajpendo.00304.2011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Insulin is believed to regulate glucose homeostasis mainly via direct effects on the liver, muscle, and adipose tissues. The contribution of insulin's central nervous system effects to disorders of glucose metabolism has received less attention. To evaluate whether postnatal reduction of insulin receptors (IRs) within the ventromedial hypothalamus (VMH), a brain region critical for glucose sensing, contributes to disorders of peripheral glucose metabolism, we microinjected a lentiviral vector expressing an antisense sequence to knockdown IRs or a control lentiviral vector into the VMH of nonobese nondiabetic rats. After 3-4 mo, we assessed 1) glucose tolerance, 2) hepatic insulin sensitivity, and 3) insulin and glucagon secretion, using the glucose clamp technique. Knockdown of IRs locally in the VMH caused glucose intolerance without altering body weight. Increments of plasma insulin during a euglycemic clamp study failed to suppress endogenous glucose production and produced a paradoxical rise in plasma glucagon in the VMH-IR knockdown rats. Unexpectedly, these animals also displayed a 40% reduction (P < 0.05) in insulin secretion in response to an identical hyperglycemic stimulus (∼220 mg/dl). Our data demonstrate that chronic suppression of VMH-IR gene expression is sufficient to impair glucose metabolism as well as α-cell and β-cell function in nondiabetic, nonobese rats. These data suggest that insulin resistance within the VMH may be a significant contributor to the development of type 2 diabetes.
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Affiliation(s)
- Sachin A Paranjape
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
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Gallagher EJ, Leroith D, Karnieli E. Insulin resistance in obesity as the underlying cause for the metabolic syndrome. ACTA ACUST UNITED AC 2011; 77:511-23. [PMID: 20960553 DOI: 10.1002/msj.20212] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The metabolic syndrome affects more than a third of the US population, predisposing to the development of type 2 diabetes and cardiovascular disease. The 2009 consensus statement from the International Diabetes Federation, American Heart Association, World Heart Federation, International Atherosclerosis Society, International Association for the Study of Obesity, and the National Heart, Lung, and Blood Institute defines the metabolic syndrome as 3 of the following elements: abdominal obesity, elevated blood pressure, elevated triglycerides, low high-density lipoprotein cholesterol, and hyperglycemia. Many factors contribute to this syndrome, including decreased physical activity, genetic predisposition, chronic inflammation, free fatty acids, and mitochondrial dysfunction. Insulin resistance appears to be the common link between these elements, obesity and the metabolic syndrome. In normal circumstances, insulin stimulates glucose uptake into skeletal muscle, inhibits hepatic gluconeogenesis, and decreases adipose-tissue lipolysis and hepatic production of very-low-density lipoproteins. Insulin signaling in the brain decreases appetite and prevents glucose production by the liver through neuronal signals from the hypothalamus. Insulin resistance, in contrast, leads to the release of free fatty acids from adipose tissue, increased hepatic production of very-low-density lipoproteins and decreased high-density lipoproteins. Increased production of free fatty acids, inflammatory cytokines, and adipokines and mitochondrial dysfunction contribute to impaired insulin signaling, decreased skeletal muscle glucose uptake, increased hepatic gluconeogenesis, and β cell dysfunction, leading to hyperglycemia. In addition, insulin resistance leads to the development of hypertension by impairing vasodilation induced by nitric oxide. In this review, we discuss normal insulin signaling and the mechanisms by which insulin resistance contributes to the development of the metabolic syndrome.
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Shiraishi JI, Yanagita K, Fukumori R, Sugino T, Fujita M, Kawakami SI, McMurtry JP, Bungo T. Comparisons of insulin related parameters in commercial-type chicks: Evidence for insulin resistance in broiler chicks. Physiol Behav 2011; 103:233-9. [PMID: 21316379 DOI: 10.1016/j.physbeh.2011.02.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 01/07/2011] [Accepted: 02/04/2011] [Indexed: 11/19/2022]
Abstract
The aim of this study is to elucidate whether insulin acts differentially within the central nervous system (CNS) of two types of commercial chicks to control ingestive behavior. Male layer and broiler chicks (4-day-old) were intracerebroventricularly (ICV) injected with saline or insulin under satiated and starved conditions. Feed intake was measured at 30, 60 and 120 min after treatment. Secondly, blood and hypothalamus were collected from both chick types under ad libitum feeding and fasting for 24 h. Plasma insulin concentration was measured by time-resolved fluoro-immunoassay. Hypothalamic insulin receptor mRNA expression levels were measured by quantitative RT-PCR. The ICV injection of insulin significantly inhibited feed consumption in layer chicks when compared with saline (P<0.05), but not broiler chicks (P>0.1). Plasma insulin concentration of both chick types significantly decreased following 24 h of fasting, while insulin concentrations in the broiler chicks were significantly higher compared to the layers fed under ad libitum conditions. Hypothalamic insulin receptor mRNA expression levels were significantly lower (P<0.05) in broiler chicks than in layer ones under ad libitum feeding. Feed deprivation significantly decreased insulin receptor mRNA levels in layer chicks (P<0.01), but not in broiler chicks (P>0.1). Moreover, plasma insulin concentrations correlated negatively with hypothalamic insulin receptor protein expression in the two types of chicks fed ad libitum (P<0.05). These results suggest that insulin resistance exists in the CNS of broiler chicks, possibly due to persistent hyperinsulinemia, which results in a down-regulation of CNS insulin receptor expression compared to that in layer chicks.
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Affiliation(s)
- Jun-Ichi Shiraishi
- Laboratory of Animal Behavior and Physiology, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
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Hirvonen J, Virtanen KA, Nummenmaa L, Hannukainen JC, Honka MJ, Bucci M, Nesterov SV, Parkkola R, Rinne J, Iozzo P, Nuutila P. Effects of insulin on brain glucose metabolism in impaired glucose tolerance. Diabetes 2011; 60:443-7. [PMID: 21270256 PMCID: PMC3028343 DOI: 10.2337/db10-0940] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Insulin stimulates brain glucose metabolism, but this effect of insulin is already maximal at fasting concentrations in healthy subjects. It is not known whether insulin is able to stimulate glucose metabolism above fasting concentrations in patients with impaired glucose tolerance. RESEARCH DESIGN AND METHODS We studied the effects of insulin on brain glucose metabolism and cerebral blood flow in 13 patients with impaired glucose tolerance and nine healthy subjects using positron emission tomography (PET). All subjects underwent PET with both [(18)F]fluorodeoxyglucose (for brain glucose metabolism) and [(15)O]H(2)O (for cerebral blood flow) in two separate conditions (in the fasting state and during a euglycemic-hyperinsulinemic clamp). Arterial blood samples were acquired during the PET scans to allow fully quantitative modeling. RESULTS The hyperinsulinemic clamp increased brain glucose metabolism only in patients with impaired glucose tolerance (whole brain: +18%, P = 0.001) but not in healthy subjects (whole brain: +3.9%, P = 0.373). The hyperinsulinemic clamp did not alter cerebral blood flow in either group. CONCLUSIONS We found that insulin stimulates brain glucose metabolism at physiological postprandial levels in patients with impaired glucose tolerance but not in healthy subjects. These results suggest that insulin stimulation of brain glucose metabolism is maximal at fasting concentrations in healthy subjects but not in patients with impaired glucose tolerance.
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Affiliation(s)
- Jussi Hirvonen
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
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Halmos T, Suba I. The role of the brain in the regulation of metabolism and energy expenditure: the central role of insulin, the insulin resistance of the brain. Orv Hetil 2011; 152:83-91. [DOI: 10.1556/oh.2011.28981] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Regulatory role of the brain in energy expenditure, appetite, glucose metabolism, and central effects of insulin has been prominently studied. Certain neurons in the hypothalamus increase or decrease appetite via orexigenes and anorexigenes, regulating energy balance and food intake. Hypothalamus is the site of afferent and efferent stimuli between special nuclei and beta- and alpha cells, and it regulates induction/inhibition of glucose output from the liver. Incretines, produced in intestine and in certain brain cells (brain-gut hormones), link to special receptors in the hypothalamus. Central role of insulin has been proved both in animals and in humans. Insulin gets across the blood-brain barrier, links to special hypothalamic receptors, regulating peripheral glucose metabolism. Central glucose sensing, via “glucose-excited” and “glucose-inhibited” cells have outstanding role. Former are active in hyperglycaemia, latter in hypoglycaemia, via influencing beta– and alpha cells, independently of traditional metabolic pathways. Evidence of brain insulin resistance needs centrally acting drugs, paradigm changes in therapy and prevention of metabolic syndrome, diabetes, cardiovascular and oncological diseases. Orv. Hetil., 2011, 152, 83–91.
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Affiliation(s)
- Tamás Halmos
- MAZSIHISZ Szeretet Kórház Metabolikus Ambulancia Budapest Amerikai út 53–55. 1145
| | - Ilona Suba
- Bajcsy-Zsilinszky Kórház-Rendelőintézet Tüdőgondozó Budapest
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