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Wei Y, Shao J, Pang Y, Wen C, Wei K, Peng L, Wang Y, Wei X. Antidiabetic Potential of Tea and Its Active Compounds: From Molecular Mechanism to Clinical Evidence. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:11837-11853. [PMID: 38743877 DOI: 10.1021/acs.jafc.3c08492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic β-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.
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Affiliation(s)
- Yang Wei
- Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P.R. China
| | - Jie Shao
- Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P.R. China
| | - Yuxuan Pang
- Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P.R. China
| | - Caican Wen
- Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P.R. China
| | - Kang Wei
- Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P.R. China
| | - Lanlan Peng
- Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P.R. China
| | - Yuanfeng Wang
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, P.R. China
| | - Xinlin Wei
- Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P.R. China
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Hill TG, Hill DJ. The Importance of Intra-Islet Communication in the Function and Plasticity of the Islets of Langerhans during Health and Diabetes. Int J Mol Sci 2024; 25:4070. [PMID: 38612880 PMCID: PMC11012451 DOI: 10.3390/ijms25074070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Islets of Langerhans are anatomically dispersed within the pancreas and exhibit regulatory coordination between islets in response to nutritional and inflammatory stimuli. However, within individual islets, there is also multi-faceted coordination of function between individual beta-cells, and between beta-cells and other endocrine and vascular cell types. This is mediated partly through circulatory feedback of the major secreted hormones, insulin and glucagon, but also by autocrine and paracrine actions within the islet by a range of other secreted products, including somatostatin, urocortin 3, serotonin, glucagon-like peptide-1, acetylcholine, and ghrelin. Their availability can be modulated within the islet by pericyte-mediated regulation of microvascular blood flow. Within the islet, both endocrine progenitor cells and the ability of endocrine cells to trans-differentiate between phenotypes can alter endocrine cell mass to adapt to changed metabolic circumstances, regulated by the within-islet trophic environment. Optimal islet function is precariously balanced due to the high metabolic rate required by beta-cells to synthesize and secrete insulin, and they are susceptible to oxidative and endoplasmic reticular stress in the face of high metabolic demand. Resulting changes in paracrine dynamics within the islets can contribute to the emergence of Types 1, 2 and gestational diabetes.
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Affiliation(s)
- Thomas G. Hill
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - David J. Hill
- Lawson Health Research Institute, St. Joseph’s Health Care, London, ON N6A 4V2, Canada;
- Departments of Medicine, Physiology and Pharmacology, Western University, London, ON N6A 3K7, Canada
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Altaf N, Rehman NU, Karim N, Khan I, Halim SA, Alotaibi BS, Hamad RS, Batiha GES, Tayyeb JZ, Turkistani A, Khan A, Al-Harrasi A. Attenuation of Streptozotocin-Induced Diabetic Neuropathic Allodynia by Flavone Derivative Through Modulation of GABA-ergic Mechanisms and Endogenous Biomarkers. Neurochem Res 2024; 49:980-997. [PMID: 38170385 DOI: 10.1007/s11064-023-04078-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 11/19/2023] [Accepted: 11/27/2023] [Indexed: 01/05/2024]
Abstract
Diabetic neuropathic pain is one of the most devasting disorders of peripheral nervous system. The loss of GABAergic inhibition is associated with the development of painful diabetic neuropathy. The current study evaluated the potential of 3-Hydroxy-2-methoxy-6-methyl flavone (3-OH-2'MeO6MF), to ameliorate peripheral neuropathic pain using an STZ-induced hyperglycemia rat model. The pain threshold was assessed by tail flick, cold, mechanical allodynia, and formalin test on days 0, 14, 21, and 28 after STZ administration accompanied by evaluation of several biochemical parameters. Administration of 3-OH-2'-MeO6MF (1,10, 30, and 100 mg/kg, i.p) significantly enhanced the tail withdrawal threshold in tail-flick and tail cold allodynia tests. 3-OH-2'-MeO6MF also increased the paw withdrawal threshold in mechanical allodynia and decreased paw licking time in the formalin test. Additionally, 3-OH-2'-MeO6MF also attenuated the increase in concentrations of myeloperoxidase (MPO), thiobarbituric acid reactive substances (TBARS), nitrite, TNF-α, and IL 6 along with increases in glutathione (GSH). Pretreatment of pentylenetetrazole (PTZ) (40 mg/kg, i.p.) abolished the antinociceptive effect of 3-OH-2'-MeO6MF in mechanical allodynia. Besides, the STZ-induced alterations in the GABA concentration and GABA transaminase activity attenuated by 3-OH-2'-MeO6MF treatment suggest GABAergic mechanisms. Molecular docking also authenticates the involvement of α2β2γ2L GABA-A receptors and GABA-T enzyme in the antinociceptive activities of 3-OH-2'-MeO6MF.
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Affiliation(s)
- Nouman Altaf
- Department of Pharmacy, University of Malakand, Chakdara, Lower Dir, KPK, Pakistan
| | - Najeeb Ur Rehman
- Natural and Medical Sciences Research Center, University of Nizwa, Birkat al Mouz, Initial Campus, 616, Nizwa, Sultanate of Oman
| | - Nasiara Karim
- Department of Pharmacy, University of Malakand, Chakdara, Lower Dir, KPK, Pakistan.
- Department of Pharmacy, University of Peshawar, Peshawar, KPK, Pakistan.
| | - Imran Khan
- Department of Pharmacy, University of Swabi, Swabi, KPK, Pakistan
| | - Sobia Ahsan Halim
- Natural and Medical Sciences Research Center, University of Nizwa, Birkat al Mouz, Initial Campus, 616, Nizwa, Sultanate of Oman
| | - Badriyah S Alotaibi
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah bint Abdulrahman University, P.O. Box 84428, 11671, Riyadh, Saudi Arabia
| | - Rabab S Hamad
- Biological Sciences Department, College of Science, King Faisal University, 31982, Al Ahsa, Saudi Arabia
- Central Laboratory, Theodor Bilharz Research Institute, Giza, 12411, Egypt
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, AlBeheira, Egypt
| | - Jehad Zuhair Tayyeb
- Department of Clinical Biochemistry, College of Medicine, University of Jeddah, 23890, Jeddah, Saudi Arabia
| | - Areej Turkistani
- Department of Pharmacology and Toxicology, College of Medicine, Taif University, 21944, Taif, Kingdom of Saudi Arabia
| | - Ajmal Khan
- Natural and Medical Sciences Research Center, University of Nizwa, Birkat al Mouz, Initial Campus, 616, Nizwa, Sultanate of Oman.
| | - Ahmed Al-Harrasi
- Natural and Medical Sciences Research Center, University of Nizwa, Birkat al Mouz, Initial Campus, 616, Nizwa, Sultanate of Oman.
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Aldous N, Moin ASM, Abdelalim EM. Pancreatic β-cell heterogeneity in adult human islets and stem cell-derived islets. Cell Mol Life Sci 2023; 80:176. [PMID: 37270452 DOI: 10.1007/s00018-023-04815-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/27/2023] [Accepted: 05/19/2023] [Indexed: 06/05/2023]
Abstract
Recent studies reported that pancreatic β-cells are heterogeneous in terms of their transcriptional profiles and their abilities for insulin secretion. Sub-populations of pancreatic β-cells have been identified based on the functionality and expression of specific surface markers. Under diabetes condition, β-cell identity is altered leading to different β-cell sub-populations. Furthermore, cell-cell contact between β-cells and other endocrine cells within the islet play an important role in regulating insulin secretion. This highlights the significance of generating a cell product derived from stem cells containing β-cells along with other major islet cells for treating patients with diabetes, instead of transplanting a purified population of β-cells. Another key question is how close in terms of heterogeneity are the islet cells derived from stem cells? In this review, we summarize the heterogeneity in islet cells of the adult pancreas and those generated from stem cells. In addition, we highlight the significance of this heterogeneity in health and disease conditions and how this can be used to design a stem cell-derived product for diabetes cell therapy.
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Affiliation(s)
- Noura Aldous
- College of Health and Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, Doha, Qatar
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, PO Box 34110, Doha, Qatar
| | - Abu Saleh Md Moin
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, PO Box 34110, Doha, Qatar
- Research Department, Royal College of Surgeons in Ireland Bahrain, Adliya, Kingdom of Bahrain
| | - Essam M Abdelalim
- College of Health and Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, Doha, Qatar.
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Education City, PO Box 34110, Doha, Qatar.
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Tseng WEJ, Chang CW, Hwang JS, Ko PC, Liu CJ, Lim SN. Association of Long-term Antiseizure Medication Use and Incident Type 2 Diabetes Mellitus. Neurology 2023; 100:e2071-e2082. [PMID: 36963840 PMCID: PMC10186244 DOI: 10.1212/wnl.0000000000207222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 02/09/2023] [Indexed: 03/26/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Diabetes mellitus (DM) contributes significantly to metabolic syndrome and cardiovascular events, and it may be a comorbidity of epilepsy. The objective of this study was to investigate whether long-term antiseizure medication (ASM) use is associated with the risk of developing type 2 diabetes. METHODS We analyzed data from the Chang Gung Research Database. Patients aged ≥45 years who received ASM treatment from January 2001 to May 2019 were identified. Patients with DM-associated diseases and short-term ASM use were excluded. The patients were classified into nonenzyme interaction, enzyme-inducing, enzyme-inhibiting, and mixed ASM groups. The rate of incident diabetes associated with individual ASM was further analyzed. Propensity score weighting was performed to balance between-group differences. Analyses were conducted with Cox proportional regression models and stabilized inverse probability of treatment weighting (IPTW). Hazard ratios (HRs) were calculated at 3, 4, 6, and 9 years after the index date and the end of follow-up. RESULTS A total of 5,103 patients were analyzed, of whom 474 took nonenzyme interaction ASMs, 1,156 took enzyme-inducing ASMs, 336 took enzyme-inhibiting ASMs, and 3,137 took mixed ASMs. During follow-up (39,248 person-years), 663 patients developed new-onset DM, and the prevalence was 13.0%. The incidence of DM plateaued at 6-9 years after ASM initiation. Enzyme-inhibiting ASMs were significantly associated with a higher HR starting at the third year and then throughout the study period. The HRs were 1.93 (95% CI 1.33-2.80), 1.85 (95% CI 1.24-2.75), and 2.08 (95% CI 1.43-3.03) in unadjusted, adjusted, and stabilized IPTW models, respectively, at the end of follow-up. The dosing of ASM did not increase the risk of DM, and none of the individual ASM analyses reached statistical significance. DISCUSSION The long-term use of enzyme-inhibiting ASMs was associated with an increased risk of incident DM, and the risk increased with the duration of treatment. These findings may guide the choice of drugs in those requiring long-term ASM therapy, particularly in high-risk individuals. CLASSIFICATION OF EVIDENCE This study provides Class IV evidence that enzyme-inhibiting ASMs were associated with an increased risk of developing DM compared with nonenzyme interaction ASMs.
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Affiliation(s)
- Wei-En Johnny Tseng
- From the Section of Epilepsy (W.-E.J.T., C.-W.C., C.-J.L., S.-N.L.), Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center, and Chang Gung University College of Medicine; PhD Program in Biomedical Engineering (W.-E.J.T.), Chang Gung University; Division of Endocrinology and Metabolism (J.-S.H.), Department of Internal Medicine, Linkou Chang Gung Memorial Hospital; and Center for Big Data Analytics and Statistics (P.-C.K.), Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chun-Wei Chang
- From the Section of Epilepsy (W.-E.J.T., C.-W.C., C.-J.L., S.-N.L.), Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center, and Chang Gung University College of Medicine; PhD Program in Biomedical Engineering (W.-E.J.T.), Chang Gung University; Division of Endocrinology and Metabolism (J.-S.H.), Department of Internal Medicine, Linkou Chang Gung Memorial Hospital; and Center for Big Data Analytics and Statistics (P.-C.K.), Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Jawl-Shan Hwang
- From the Section of Epilepsy (W.-E.J.T., C.-W.C., C.-J.L., S.-N.L.), Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center, and Chang Gung University College of Medicine; PhD Program in Biomedical Engineering (W.-E.J.T.), Chang Gung University; Division of Endocrinology and Metabolism (J.-S.H.), Department of Internal Medicine, Linkou Chang Gung Memorial Hospital; and Center for Big Data Analytics and Statistics (P.-C.K.), Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Po-Chuan Ko
- From the Section of Epilepsy (W.-E.J.T., C.-W.C., C.-J.L., S.-N.L.), Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center, and Chang Gung University College of Medicine; PhD Program in Biomedical Engineering (W.-E.J.T.), Chang Gung University; Division of Endocrinology and Metabolism (J.-S.H.), Department of Internal Medicine, Linkou Chang Gung Memorial Hospital; and Center for Big Data Analytics and Statistics (P.-C.K.), Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chun-Jing Liu
- From the Section of Epilepsy (W.-E.J.T., C.-W.C., C.-J.L., S.-N.L.), Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center, and Chang Gung University College of Medicine; PhD Program in Biomedical Engineering (W.-E.J.T.), Chang Gung University; Division of Endocrinology and Metabolism (J.-S.H.), Department of Internal Medicine, Linkou Chang Gung Memorial Hospital; and Center for Big Data Analytics and Statistics (P.-C.K.), Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Siew-Na Lim
- From the Section of Epilepsy (W.-E.J.T., C.-W.C., C.-J.L., S.-N.L.), Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center, and Chang Gung University College of Medicine; PhD Program in Biomedical Engineering (W.-E.J.T.), Chang Gung University; Division of Endocrinology and Metabolism (J.-S.H.), Department of Internal Medicine, Linkou Chang Gung Memorial Hospital; and Center for Big Data Analytics and Statistics (P.-C.K.), Chang Gung Memorial Hospital, Taoyuan, Taiwan.
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Jin Z, Korol SV. GABA signalling in human pancreatic islets. Front Endocrinol (Lausanne) 2023; 14:1059110. [PMID: 36891061 PMCID: PMC9986413 DOI: 10.3389/fendo.2023.1059110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 02/09/2023] [Indexed: 02/22/2023] Open
Abstract
The pancreatic islets are essential microorgans controlling the glucose level in the blood. The islets consist of different cell types which communicate with each other by means of auto- and paracrine interactions. One of the communication molecules produced by and released within the islets is γ-aminobutyric acid (GABA), a well-known inhibitor of neuronal excitability in the mammalian nervous system. Interestingly, GABA is also present in the blood in the nanomolar concentration range. Thus, GABA can affect not only islet function per se (e.g. hormone secretion) but also interactions between immune cells and the pancreatic islet cells in physiological conditions and in pathological states (particularly in type 1 diabetes). In the last decade the interest in GABA signalling in islets has increased. The broad research scope ranges from fundamental physiological studies at the molecular and cellular level to pathological implications and clinical trials. The aim of this mini-review is to outline the current status of the islet GABA field mostly in relation to human islets, to identify the gaps in the current knowledge and what clinical implications GABA signalling may have in islets.
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Zhang H, Feng X, Liu S, Ren F, Wang J. Effects of high hydrostatic pressure on nutritional composition and cooking quality of whole grains and legumes. INNOV FOOD SCI EMERG 2022. [DOI: 10.1016/j.ifset.2022.103239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Hagan DW, Ferreira SM, Santos GJ, Phelps EA. The role of GABA in islet function. Front Endocrinol (Lausanne) 2022; 13:972115. [PMID: 36246925 PMCID: PMC9558271 DOI: 10.3389/fendo.2022.972115] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Gamma aminobutyric acid (GABA) is a non-proteinogenic amino acid and neurotransmitter that is produced in the islet at levels as high as in the brain. GABA is synthesized by the enzyme glutamic acid decarboxylase (GAD), of which the 65 kDa isoform (GAD65) is a major autoantigen in type 1 diabetes. Originally described to be released via synaptic-like microvesicles or from insulin secretory vesicles, beta cells are now understood to release substantial quantities of GABA directly from the cytosol via volume-regulated anion channels (VRAC). Once released, GABA influences the activity of multiple islet cell types through ionotropic GABAA receptors and metabotropic GABAB receptors. GABA also interfaces with cellular metabolism and ATP production via the GABA shunt pathway. Beta cells become depleted of GABA in type 1 diabetes (in remaining beta cells) and type 2 diabetes, suggesting that loss or reduction of islet GABA correlates with diabetes pathogenesis and may contribute to dysfunction of alpha, beta, and delta cells in diabetic individuals. While the function of GABA in the nervous system is well-understood, the description of the islet GABA system is clouded by differing reports describing multiple secretion pathways and effector functions. This review will discuss and attempt to unify the major experimental results from over 40 years of literature characterizing the role of GABA in the islet.
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Affiliation(s)
- D. Walker Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Sandra M. Ferreira
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Gustavo J. Santos
- Islet Biology and Metabolism Lab – I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis, Brazil
| | - Edward A. Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
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Habegger KM. Cross Talk Between Insulin and Glucagon Receptor Signaling in the Hepatocyte. Diabetes 2022; 71:1842-1851. [PMID: 35657690 PMCID: PMC9450567 DOI: 10.2337/dbi22-0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/19/2022] [Indexed: 11/13/2022]
Abstract
While the consumption of external energy (i.e., feeding) is essential to life, this action induces a temporary disturbance of homeostasis in an animal. A primary example of this effect is found in the regulation of glycemia. In the fasted state, stored energy is released to maintain physiological glycemic levels. Liver glycogen is liberated to glucose, glycerol and (glucogenic) amino acids are used to build new glucose molecules (i.e., gluconeogenesis), and fatty acids are oxidized to fuel long-term energetic demands. This regulation is driven primarily by the counterregulatory hormones epinephrine, growth hormone, cortisol, and glucagon. Conversely, feeding induces a rapid influx of diverse nutrients, including glucose, that disrupt homeostasis. Consistently, a host of hormonal and neural systems under the coordination of insulin are engaged in the transition from fasting to prandial states to reduce this disruption. The ultimate action of these systems is to appropriately store the newly acquired energy and to return to the homeostatic norm. Thus, at first glance it is tempting to assume that glucagon is solely antagonistic regarding the anabolic effects of insulin. We have been intrigued by the role of glucagon in the prandial transition and have attempted to delineate its role as beneficial or inhibitory to glycemic control. The following review highlights this long-known yet poorly understood hormone.
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Affiliation(s)
- Kirk M. Habegger
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
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The relationship between GAD65 autoantibody and the risk of T1DM onset. J Diabetes Metab Disord 2022. [PMID: 36404832 PMCID: PMC9672278 DOI: 10.1007/s40200-022-01098-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Objectives Type 1 diabetes mellitus (T1DM) is a well-known autoimmune disease, characterized by β-cell destruction in pancreas islet cells, which results insulin deficiency and subsequent hyperglycemic sequelae. While there is screening for type 2 DM that leads to better glycemic control and outcome, the majority of T1DM patients are diagnosed when much of the pancreatic cells and their function are disturbed. The aim of this article is to present an overview of the effective factors in the positivity of Glutamic acid decarboxylase antibody )GADA( and identifying the high-risk individuals for T1DM. Methods We searched English literature available at National Library of Medicine via PubMed, and Google Scholar through December 2020. Finally, 79 papers have been included in the study. Studies were summarized based on the number of positive autoantibodies and onset of T1DM over time and GADA correlation with different variables. Conclusions GADA is an easy marker to measure that can be detected many months prior to the clinical presentation and remains positive even after early childhood.
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Tu J, Jin Y, Zhuo J, Cao X, Liu G, Du H, Liu L, Wang J, Xiao H. Exogenous GABA improves the antioxidant and anti-aging ability of silkworm (Bombyx mori). Food Chem 2022; 383:132400. [DOI: 10.1016/j.foodchem.2022.132400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/09/2022] [Accepted: 02/07/2022] [Indexed: 11/30/2022]
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Sarnobat D, Charlotte Moffett R, Flatt PR, Irwin N, Tarasov AI. GABA and insulin but not nicotinamide augment α- to β-cell transdifferentiation in insulin-deficient diabetic mice. Biochem Pharmacol 2022; 199:115019. [DOI: 10.1016/j.bcp.2022.115019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/23/2022] [Accepted: 03/23/2022] [Indexed: 12/30/2022]
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Shimizu-Okabe C, Okada S, Okamoto S, Masuzaki H, Takayama C. Specific Expression of KCC2 in the α Cells of Normal and Type 1 Diabetes Model Mouse Pancreatic Islets. Acta Histochem Cytochem 2022; 55:47-56. [PMID: 35444351 PMCID: PMC8913275 DOI: 10.1267/ahc.21-00078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/22/2021] [Indexed: 01/14/2023] Open
Abstract
Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the mature brain; however, it acts excitatory during development. This difference in action depends on the intracellular chloride ion concentration, primarily regulated by potassium chloride co-transporter2 (KCC2). Sufficient KCC2 expression results in its inhibitory action. GABA is also abundant in pancreatic islets, where it acts differentially on the islet cells, and is involved in carbohydrate metabolism. However, the mechanisms underlying the differential action remain unknown. We performed immunohistochemistry for glutamic acid decarboxylase (GAD), a synthetic enzyme for GABA, and KCC2 in normal adult islets. GAD was co-localized with insulin in β cells, whereas KCC2 was expressed in glucagon-positive α cells. These results are in line with previous observations that GABA decreases glucagon release but increases insulin release, and suggest that GABA and insulin may work together in reducing blood glucose levels under hyperglycemia. Next, we examined the streptozotocin-induced type1 diabetes mellitus mouse model. GAD and insulin expression levels were markedly decreased. KCC2 was expressed in glucagon-positive cells, whereas insulin- and somatostatin-positive cells were KCC2-negative. These findings suggest that in diabetes model, reduced GABA release may cause disinhibition of glucagon release, resulting in increased blood sugar levels and the maintenance of hyperglycemic state.
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Affiliation(s)
| | - Shigeki Okada
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus
| | - Shiki Okamoto
- Division of Endocrinology, Diabetes and Metabolism, Hematology, Rheumatology School of Medicine, University of the Ryukyus
| | - Hiroaki Masuzaki
- Division of Endocrinology, Diabetes and Metabolism, Hematology, Rheumatology School of Medicine, University of the Ryukyus
| | - Chitoshi Takayama
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus
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The Case for Clinical Trials with Novel GABAergic Drugs in Diabetes Mellitus and Obesity. Life (Basel) 2022; 12:life12020322. [PMID: 35207609 PMCID: PMC8876029 DOI: 10.3390/life12020322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/09/2022] [Accepted: 02/16/2022] [Indexed: 11/17/2022] Open
Abstract
Obesity and diabetes mellitus have become the surprising menaces of relative economic well-being worldwide. Gamma amino butyric acid (GABA) has a prominent role in the control of blood glucose, energy homeostasis as well as food intake at several levels of regulation. The effects of GABA in the body are exerted through ionotropic GABAA and metabotropic GABAB receptors. This treatise will focus on the pharmacologic targeting of GABAA receptors to reap beneficial therapeutic effects in diabetes mellitus and obesity. A new crop of drugs selectively targeting GABAA receptors has been under investigation for efficacy in stroke recovery and cognitive deficits associated with schizophrenia. Although these trials have produced mixed outcomes the compounds are safe to use in humans. Preclinical evidence is summarized here to support the rationale of testing some of these compounds in diabetic patients receiving insulin in order to achieve better control of blood glucose levels and to combat the decline of cognitive performance. Potential therapeutic benefits could be achieved (i) By resetting the hypoglycemic counter-regulatory response; (ii) Through trophic actions on pancreatic islets, (iii) By the mobilization of antioxidant defence mechanisms in the brain. Furthermore, preclinical proof-of-concept work, as well as clinical trials that apply the novel GABAA compounds in eating disorders, e.g., olanzapine-induced weight-gain, also appear warranted.
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Sohrabipour S, Sharifi MR, Sharifi M, Talebi A, Soltani N. Combination Therapy with GABA and MgSO 4 Improves Insulin Sensitivity in Type 2 Diabetic Rat. Int J Endocrinol 2022; 2022:2144615. [PMID: 35211170 PMCID: PMC8863457 DOI: 10.1155/2022/2144615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Gamma-aminobutyric acid (GABA) and magnesium sulfate (MgSO4) play a crucial role in glycemic control. Therefore, we studied the effect of combination therapy with GABA and MgSO4 to improve insulin sensitivity in diabetes induced by streptozotocin as well as high-fat diet in a diabetic rat model. Design and Methods. Forty randomly selected rats were assigned to four groups: nondiabetic control group was fed the normal diet, insulin-resistant diabetic rat model was induced by streptozotocin and high-fat diet, GABA + MgSO4 group received GABA and MgSO4, and insulin group was treated with insulin. Body weight, abdominal fat, blood glucose, serum insulin, and glucagon concentration were measured. The glucose clamp technique, glucose tolerance test, and insulin tolerance test were performed to study insulin sensitivity. Also, the expressions of glucose 6 phosphatase, glucagon receptor, and phosphoenolpyruvate carboxykinase genes in liver were assessed for the gluconeogenesis pathway. Protein translocation and glucose transporter 4 (Glut4) genes expression in muscle were also assessed. RESULTS Combination of GABA + MgSO4 or insulin therapy enhanced insulin level, glycemic control, glucose and insulin tolerance test, some enzymes expression in the gluconeogenesis pathway, body fat, body weight, and glucagon receptor in diabetic rats. Moreover, an increase was observed in protein and gene expression of Glut4. Insulin sensitivity in combination therapy was more than the insulin group. CONCLUSIONS GABA and MgSO4 enhanced insulin sensitivity via increasing Glut4 and reducing the gluconeogenesis enzyme and glucagon receptor gene expressions.
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Affiliation(s)
- Shahla Sohrabipour
- Endocrinology and Metabolism Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Mohammad Reza Sharifi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammadreza Sharifi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ardeshir Talebi
- Department of Clinical Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nepton Soltani
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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16
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Role of Postbiotics in Diabetes Mellitus: Current Knowledge and Future Perspectives. Foods 2021; 10:foods10071590. [PMID: 34359462 PMCID: PMC8306164 DOI: 10.3390/foods10071590] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/29/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022] Open
Abstract
In the last decade, the gastrointestinal microbiota has been recognised as being essential for health. Indeed, several publications have documented the suitability of probiotics, prebiotics, and symbiotics in the management of different diseases such as diabetes mellitus (DM). Advances in laboratory techniques have allowed the identification and characterisation of new biologically active molecules, referred to as “postbiotics”. Postbiotics are defined as functional bioactive compounds obtained from food-grade microorganisms that confer health benefits when administered in adequate amounts. They include cell structures, secreted molecules or metabolic by-products, and inanimate microorganisms. This heterogeneous group of molecules presents a broad range of mechanisms and may exhibit some advantages over traditional “biotics” such as probiotics and prebiotics. Owing to the growing incidence of DM worldwide and the implications of the microbiota in the disease progression, postbiotics appear to be good candidates as novel therapeutic targets. In the present review, we summarise the current knowledge about postbiotic compounds and their potential application in diabetes management. Additionally, we envision future perspectives on this topic. In summary, the results indicate that postbiotics hold promise as a potential novel therapeutic strategy for DM.
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Ng XW, Chung YH, Piston DW. Intercellular Communication in the Islet of Langerhans in Health and Disease. Compr Physiol 2021; 11:2191-2225. [PMID: 34190340 DOI: 10.1002/cphy.c200026] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Blood glucose homeostasis requires proper function of pancreatic islets, which secrete insulin, glucagon, and somatostatin from the β-, α-, and δ-cells, respectively. Each islet cell type is equipped with intrinsic mechanisms for glucose sensing and secretory actions, but these intrinsic mechanisms alone cannot explain the observed secretory profiles from intact islets. Regulation of secretion involves interconnected mechanisms among and between islet cell types. Islet cells lose their normal functional signatures and secretory behaviors upon dispersal as compared to intact islets and in vivo. In dispersed islet cells, the glucose response of insulin secretion is attenuated from that seen from whole islets, coordinated oscillations in membrane potential and intracellular Ca2+ activity, as well as the two-phase insulin secretion profile, are missing, and glucagon secretion displays higher basal secretion profile and a reverse glucose-dependent response from that of intact islets. These observations highlight the critical roles of intercellular communication within the pancreatic islet, and how these communication pathways are crucial for proper hormonal and nonhormonal secretion and glucose homeostasis. Further, misregulated secretions of islet secretory products that arise from defective intercellular islet communication are implicated in diabetes. Intercellular communication within the islet environment comprises multiple mechanisms, including electrical synapses from gap junctional coupling, paracrine interactions among neighboring cells, and direct cell-to-cell contacts in the form of juxtacrine signaling. In this article, we describe the various mechanisms that contribute to proper islet function for each islet cell type and how intercellular islet communications are coordinated among the same and different islet cell types. © 2021 American Physiological Society. Compr Physiol 11:2191-2225, 2021.
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Affiliation(s)
- Xue W Ng
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
| | - Yong H Chung
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
| | - David W Piston
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
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18
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Zeigerer A, Sekar R, Kleinert M, Nason S, Habegger KM, Müller TD. Glucagon's Metabolic Action in Health and Disease. Compr Physiol 2021; 11:1759-1783. [PMID: 33792899 PMCID: PMC8513137 DOI: 10.1002/cphy.c200013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Discovered almost simultaneously with insulin, glucagon is a pleiotropic hormone with metabolic action that goes far beyond its classical role to increase blood glucose. Albeit best known for its ability to directly act on the liver to increase de novo glucose production and to inhibit glycogen breakdown, glucagon lowers body weight by decreasing food intake and by increasing metabolic rate. Glucagon further promotes lipolysis and lipid oxidation and has positive chronotropic and inotropic effects in the heart. Interestingly, recent decades have witnessed a remarkable renaissance of glucagon's biology with the acknowledgment that glucagon has pharmacological value beyond its classical use as rescue medication to treat severe hypoglycemia. In this article, we summarize the multifaceted nature of glucagon with a special focus on its hepatic action and discuss the pharmacological potential of either agonizing or antagonizing the glucagon receptor for health and disease. © 2021 American Physiological Society. Compr Physiol 11:1759-1783, 2021.
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Affiliation(s)
- Anja Zeigerer
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Revathi Sekar
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Maximilian Kleinert
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Shelly Nason
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kirk M. Habegger
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Timo D. Müller
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, Eberhard Karls University Hospitals and Clinics, Tübingen, Germany
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19
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Al-Kuraishy HM, Hussian NR, Al-Naimi MS, Al-Gareeb AI, Al-Mamorri F, Al-Buhadily AK. The Potential Role of Pancreatic γ-Aminobutyric Acid (GABA) in Diabetes Mellitus: A Critical Reappraisal. Int J Prev Med 2021; 12:19. [PMID: 34084316 PMCID: PMC8106282 DOI: 10.4103/ijpvm.ijpvm_278_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/02/2019] [Indexed: 12/31/2022] Open
Abstract
Background Diabetes mellitus (DM) is an endocrine disorder characterized by hyperglycemia, polyuria, polydipsia, and glucosuria. γ-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the central nervous system (CNS) of humans and other mammals. GABA acts on two different receptors, which are GABA-A and GABA-B. Pancreatic β-cells synthesize GABA from glutamic acid by glutamic acid decarboxylase (GAD). Aim The objective of this study was to explore the potential role of pancreatic GABA on glycemic indices in DM. Methods Evidence from experimental, preclinical, and clinical studies are evaluated for bidirectional relationships between pancreatic GABA and blood glucose disorders. A multiplicity of search strategies took on and assumed included electronic database searches of Medline and Pubmed using MeSH terms, keywords and title words during the search. Results The pancreatic GABA signaling system has a role in the regulation of pancreatic hormone secretions, inhibition of immune response, improve β-cells survival, and change α cell into β-cell. Moreover, a GABA agonist improves the antidiabetic effects of metformin. In addition, benzodiazepine receptor agonists improve pancreatic β-cell functions through GABA dependent pathway or through modulation of pancreatic adenosine and glucagon-like peptide (GLP-1). Conclusions Pancreatic GABA improves islet cell function, glucose homeostasis, and autoimmunity in DM. Orally administered GABA is safe for humans, and acts on peripheral GABA receptors and represents a new therapeutic modality for both T1DM and T2DM. Besides, GABA-A receptor agonist like benzodiazepines improves pancreatic β-cell function and insulin sensitivity through activation of GABA-A receptors.
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Affiliation(s)
- Hayder M Al-Kuraishy
- Department of Pharmacology, Toxicology, and Medicine, College of Medicine Almustansiriya University, P.O. Box 14132, Baghdad, Iraq
| | - Nawar R Hussian
- Department of Pharmacology, Toxicology, and Medicine, College of Medicine Almustansiriya University, P.O. Box 14132, Baghdad, Iraq
| | - Marwa S Al-Naimi
- Department of Pharmacology, Toxicology, and Medicine, College of Medicine Almustansiriya University, P.O. Box 14132, Baghdad, Iraq
| | - Ali I Al-Gareeb
- Department of Pharmacology, Toxicology, and Medicine, College of Medicine Almustansiriya University, P.O. Box 14132, Baghdad, Iraq
| | - Farah Al-Mamorri
- Department of Pharmacology, Toxicology, and Medicine, College of Medicine Almustansiriya University, P.O. Box 14132, Baghdad, Iraq
| | - Ali K Al-Buhadily
- Department of Pharmacology, Toxicology, and Medicine, College of Medicine Almustansiriya University, P.O. Box 14132, Baghdad, Iraq
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20
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GABA B-Receptor Agonist-Based Immunotherapy for Type 1 Diabetes in NOD Mice. Biomedicines 2021; 9:biomedicines9010043. [PMID: 33418884 PMCID: PMC7825043 DOI: 10.3390/biomedicines9010043] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/26/2020] [Accepted: 12/30/2020] [Indexed: 12/17/2022] Open
Abstract
Some immune system cells express type A and/or type B γ-aminobutyric acid receptors (GABAA-Rs and/or GABAB-Rs). Treatment with GABA, which activates both GABAA-Rs and GABAB-Rs), and/or a GABAA-R-specific agonist inhibits disease progression in mouse models of type 1 diabetes (T1D), multiple sclerosis, rheumatoid arthritis, and COVID-19. Little is known about the clinical potential of specifically modulating GABAB-Rs. Here, we tested lesogaberan, a peripherally restricted GABAB-R agonist, as an interventive therapy in diabetic NOD mice. Lesogaberan treatment temporarily restored normoglycemia in most newly diabetic NOD mice. Combined treatment with a suboptimal dose of lesogaberan and proinsulin/alum immunization in newly diabetic NOD mice or a low-dose anti-CD3 in severely hyperglycemic NOD mice greatly increased T1D remission rates relative to each monotherapy. Mice receiving combined lesogaberan and anti-CD3 displayed improved glucose tolerance and, unlike mice that received anti-CD3 alone, had some islets with many insulin+ cells, suggesting that lesogaberan helped to rapidly inhibit β-cell destruction. Hence, GABAB-R-specific agonists may provide adjunct therapies for T1D. Finally, the analysis of microarray and RNA-Seq databases suggested that the expression of GABAB-Rs and GABAA-Rs, as well as GABA production/secretion-related genes, may be a more common feature of immune cells than currently recognized.
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21
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Henquin JC. Paracrine and autocrine control of insulin secretion in human islets: evidence and pending questions. Am J Physiol Endocrinol Metab 2021; 320:E78-E86. [PMID: 33103455 DOI: 10.1152/ajpendo.00485.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin secretion by β-cells is largely controlled by circulating nutrients, hormones, and neurotransmitters. However, recent years have witnessed the multiplication of studies investigating whether local regulation also takes place within pancreatic islets, in which β-cells cohabit with several other cell types. The cell composition and architectural organization of human islets differ from those of rodent islets and are particularly favorable to cellular interactions. An impressive number of hormonal (glucagon, glucagon-like peptide-1, somatostatin, etc.) and nonhormonal products (ATP, acetylcholine, γ-aminobutyric acid, dopamine, etc.) are released by islet cells and have been implicated in a local control of insulin secretion. This review analyzes reports directly testing paracrine and autocrine control of insulin secretion in isolated human islets. Many of these studies were designed on background information collected in rodent islets. However, the perspective of the review is not to highlight species similarities or specificities but to contrast established and speculative mechanisms in human islets. It will be shown that the current evidence is convincing only for a minority of candidates for a paracrine function whereas arguments supporting a physiological role of others do not stand up to scrutiny. Several pending questions await further investigation.
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Affiliation(s)
- Jean-Claude Henquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium
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22
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Li X, Chen L, Zhu X, Lu Z, Lu Y. Effect of γ-aminobutyric acid-rich yogurt on insulin sensitivity in a mouse model of type 2 diabetes mellitus. J Dairy Sci 2020; 103:7719-7729. [PMID: 32684454 DOI: 10.3168/jds.2019-17757] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 03/24/2020] [Indexed: 12/28/2022]
Abstract
This study aimed to investigate the effect of a γ-aminobutyric acid (GABA)-rich yogurt fermented with Streptococcus thermophilus fmb-5 on insulin sensitivity in high-fat and low-dose streptozotocin-induced type 2 diabetes mellitus mice. To study the ability of the yogurt to enhance insulin sensitivity, diabetic mice were treated with 0.5, 1, or 2 g/L of GABA yogurt once a day from wk 1 to 12. Compared with results in untreated diabetic mice, treatment with different dosages of GABA yogurt was associated with increased serum insulin and fat coefficient (fat weight relative to body weight) levels, decreased blood urea nitrogen, kidney coefficient (kidney weight relative to body weight), glucose area under the curve levels, and insulin sensitivity index, but did not alter blood glucose level or body weight. The highest dosage of GABA yogurt had a greater beneficial effect with respect to insulin resistance than the lower dosages. In particular, dietary supplementation of the high dosage of GABA yogurt favorably regulated HOMA-β (homeostasis model assessment of β-cell function), total cholesterol, high-density lipoprotein cholesterol, fat coefficient, and improved islet cells morphology. These results demonstrated that 2 g/L GABA yogurt could ameliorate insulin sensitivity. The GABA-rich yogurts appeared to be responsible for health-beneficial effects in this mouse model of diabetes.
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Affiliation(s)
- Xiangfei Li
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, P. R. China; College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Lin Chen
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Xiaoyu Zhu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Zhaoxin Lu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, P. R. China.
| | - Yingjian Lu
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, P. R. China.
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23
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Chloride transporters and channels in β-cell physiology: revisiting a 40-year-old model. Biochem Soc Trans 2020; 47:1843-1855. [PMID: 31697318 PMCID: PMC6925527 DOI: 10.1042/bst20190513] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 12/13/2022]
Abstract
It is accepted that insulin-secreting β-cells release insulin in response to glucose even in the absence of functional ATP-sensitive K+ (KATP)-channels, which play a central role in a 'consensus model' of secretion broadly accepted and widely reproduced in textbooks. A major shortcoming of this consensus model is that it ignores any and all anionic mechanisms, known for more than 40 years, to modulate β-cell electrical activity and therefore insulin secretion. It is now clear that, in addition to metabolically regulated KATP-channels, β-cells are equipped with volume-regulated anion (Cl-) channels (VRAC) responsive to glucose concentrations in the range known to promote electrical activity and insulin secretion. In this context, the electrogenic efflux of Cl- through VRAC and other Cl- channels known to be expressed in β-cells results in depolarization because of an outwardly directed Cl- gradient established, maintained and regulated by the balance between Cl- transporters and channels. This review will provide a succinct historical perspective on the development of a complex hypothesis: Cl- transporters and channels modulate insulin secretion in response to nutrients.
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24
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Wendt A, Eliasson L. Pancreatic α-cells - The unsung heroes in islet function. Semin Cell Dev Biol 2020; 103:41-50. [PMID: 31983511 DOI: 10.1016/j.semcdb.2020.01.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 01/15/2023]
Abstract
The pancreatic islets of Langerhans consist of several hormone-secreting cell types important for blood glucose control. The insulin secreting β-cells are the best studied of these cell types, but less is known about the glucagon secreting α-cells. The α-cells secrete glucagon as a response to low blood glucose. The major function of glucagon is to release glucose from the glycogen stores in the liver. In both type 1 and type 2 diabetes, glucagon secretion is dysregulated further exaggerating the hyperglycaemia, and in type 1 diabetes α-cells fail to counter regulate hypoglycaemia. Although glucagon has been recognized for almost 100 years, the understanding of how glucagon secretion is regulated and how glucagon act within the islet is far from complete. However, α-cell research has taken off lately which is promising for future knowledge. In this review we aim to highlight α-cell regulation and glucagon secretion with a special focus on recent discoveries from human islets. We will present some novel aspects of glucagon function and effects of selected glucose lowering agents on glucagon secretion.
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Affiliation(s)
- Anna Wendt
- Islet Cell Exocytosis, Lund University Diabetes Centre, Department of Clinical Sciences Malmö, Lund University, Clinical Research Centre, SUS, Malmö, Sweden
| | - Lena Eliasson
- Islet Cell Exocytosis, Lund University Diabetes Centre, Department of Clinical Sciences Malmö, Lund University, Clinical Research Centre, SUS, Malmö, Sweden.
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25
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Korol SV, Jin Z, Birnir B. GABA A Receptor-Mediated Currents and Hormone mRNAs in Cells Expressing More Than One Hormone Transcript in Intact Human Pancreatic Islets. Int J Mol Sci 2020; 21:E600. [PMID: 31963438 PMCID: PMC7013858 DOI: 10.3390/ijms21020600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 11/16/2022] Open
Abstract
In pancreatic islets, the major cell-types are α, β and δ cells. The γ-aminobutyric acid (GABA) signalling system is expressed in human pancreatic islets. In single hormone transcript-expressing cells, we have previously characterized the functional properties of islet GABAA receptors (iGABAARs). Here, we extended these studies to islet cells expressing mRNAs for more than one hormone and sought for correlation between iGABAAR activity level and relative mRNA expression ratio. The single-cell RT-PCR in combination with the patch-clamp current recordings was used to examine functional properties of iGABAARs in the multiple hormone mRNA-expressing cells. We detected cells expressing double (α/β, α/δ, β/δ cell-types) and triple (α/β/δ cell-type) hormone transcripts. The most common mixed-identity cell-type was the α/β group where the cells could be grouped into β- and α-like subgroups. The β-like cells had low GCG/INS expression ratio (<0.6) and significantly higher frequency of iGABAAR single-channel openings than the α-like cells where the GCG/INS expression ratio was high (>1.2). The hormone expression levels and iGABAAR single-channel characteristics varied in the α/β/δ cell-type. Clearly, multiple hormone transcripts can be expressed in islet cells whereas iGABAAR single-channel functional properties appear to be α or β cell specific.
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Affiliation(s)
- Sergiy V. Korol
- Department of Medical Cell Biology, Uppsala University, BMC, Box 593, 75124 Uppsala, Sweden; (Z.J.); (B.B.)
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26
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Yi Z, Waseem Ghani M, Ghani H, Jiang W, Waseem Birmani M, Ye L, Bin L, Cun LG, Lilong A, Mei X. Gimmicks of gamma-aminobutyric acid (GABA) in pancreatic β-cell regeneration through transdifferentiation of pancreatic α- to β-cells. Cell Biol Int 2020; 44:926-936. [PMID: 31903671 DOI: 10.1002/cbin.11302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 01/04/2020] [Indexed: 02/06/2023]
Abstract
In vivo regeneration of lost or dysfunctional islet β cells can fulfill the promise of improved therapy for diabetic patients. To achieve this, many mitogenic factors have been attempted, including gamma-aminobutyric acid (GABA). GABA remarkably affects pancreatic islet cells' (α cells and β cells) function through paracrine and/or autocrine binding to its membrane receptors on these cells. GABA has also been studied for promoting the transformation of α cells to β cells. Nonetheless, the gimmickry of GABA-induced α-cell transformation to β cells has two different perspectives. On the one hand, GABA was found to induce α-cell transformation to β cells in vivo and insulin-secreting β-like cells in vitro. On the other hand, GABA treatment showed that it has no α- to β-cell transformation response. Here, we will summarize the physiological effects of GABA on pancreatic islet β cells with an emphasis on its regenerative effects for transdifferentiation of islet α cells to β cells. We will also critically discuss the controversial results about GABA-mediated transdifferentiation of α cells to β cells.
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Affiliation(s)
- Zhao Yi
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Muhammad Waseem Ghani
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Hammad Ghani
- Nawaz Sharif Medical College, University of Gujrat, Punjab, 50180, Pakistan
| | - Wu Jiang
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Muhammad Waseem Birmani
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Li Ye
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Liu Bin
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Lang Guan Cun
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - An Lilong
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
| | - Xiao Mei
- Department of Animal Science and Medicine, Agricultural College, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.,Department of Animal Breeding, Genetics and Reproduction, Agricultural Collage, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China
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27
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Menegaz D, Hagan DW, Almaça J, Cianciaruso C, Rodriguez-Diaz R, Molina J, Dolan RM, Becker MW, Schwalie PC, Nano R, Lebreton F, Kang C, Sah R, Gaisano HY, Berggren PO, Baekkeskov S, Caicedo A, Phelps EA. Mechanism and effects of pulsatile GABA secretion from cytosolic pools in the human beta cell. Nat Metab 2019; 1:1110-1126. [PMID: 32432213 PMCID: PMC7236889 DOI: 10.1038/s42255-019-0135-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pancreatic beta cells synthesize and secrete the neurotransmitter γ-aminobutyric acid (GABA) as a paracrine and autocrine signal to help regulate hormone secretion and islet homeostasis. Islet GABA release has classically been described as a secretory vesicle-mediated event. Yet, a limitation of the hypothesized vesicular GABA release from islets is the lack of expression of a vesicular GABA transporter in beta cells. Consequentially, GABA accumulates in the cytosol. Here we provide evidence that the human beta cell effluxes GABA from a cytosolic pool in a pulsatile manner, imposing a synchronizing rhythm on pulsatile insulin secretion. The volume regulatory anion channel (VRAC), functionally encoded by LRRC8A or Swell1, is critical for pulsatile GABA secretion. GABA content in beta cells is depleted and secretion is disrupted in islets from type 1 and type 2 diabetic patients, suggesting that loss of GABA as a synchronizing signal for hormone output may correlate with diabetes pathogenesis.
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Affiliation(s)
- Danusa Menegaz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - D Walker Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Joana Almaça
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Chiara Cianciaruso
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Rayner Rodriguez-Diaz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Judith Molina
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Robert M Dolan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Matthew W Becker
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Petra C Schwalie
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Rita Nano
- Pancreatic Islet Processing Facility, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Fanny Lebreton
- Cell Isolation and Transplantation Center, Faculty of Medicine, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Chen Kang
- Center for Cardiovascular Research and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, USA
| | - Rajan Sah
- Center for Cardiovascular Research and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, USA
| | - Herbert Y Gaisano
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Per-Olof Berggren
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- The Rolf Luft Research Center for Diabetes & Endocrinology, Karolinska Institutet, Stockholm, Sweden
- Division of Integrative Biosciences and Biotechnology, WCU Program, University of Science and Technology, Pohang, Korea
| | - Steinunn Baekkeskov
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
- Departments of Medicine and Microbiology/Immunology, Diabetes Center, University of California San Francisco, San Francisco, CA, USA.
| | - Alejandro Caicedo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, USA.
- Program in Neuroscience, Miller School of Medicine, University of Miami, Miami, FL, USA.
| | - Edward A Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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28
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Tian J, Dang H, O'Laco KA, Song M, Tiu BC, Gilles S, Zakarian C, Kaufman DL. Homotaurine Treatment Enhances CD4 + and CD8 + Regulatory T Cell Responses and Synergizes with Low-Dose Anti-CD3 to Enhance Diabetes Remission in Type 1 Diabetic Mice. Immunohorizons 2019; 3:498-510. [PMID: 31636084 PMCID: PMC6823932 DOI: 10.4049/immunohorizons.1900019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 10/02/2019] [Indexed: 12/16/2022] Open
Abstract
Immune cells express γ-aminobutyric acid receptors (GABA-R), and GABA administration can inhibit effector T cell responses in models of autoimmune disease. The pharmacokinetic properties of GABA, however, may be suboptimal for clinical applications. The amino acid homotaurine is a type A GABA-R (GABAA-R) agonist with good pharmacokinetics and appears safe for human consumption. In this study, we show that homotaurine inhibits in vitro T cell proliferation to a similar degree as GABA but at lower concentrations. In vivo, oral homotaurine treatment had a modest ability to reverse hyperglycemia in newly hyperglycemic NOD mice but was ineffective after the onset of severe hyperglycemia. In severely diabetic NOD mice, the combination of homotaurine and low-dose anti-CD3 treatment significantly increased 1) disease remission, 2) the percentages of splenic CD4+ and CD8+ regulatory T cells compared with anti-CD3 alone, and 3) the frequencies of CD4+ and CD8+ regulatory T cells in the pancreatic lymph nodes compared with homotaurine monotherapy. Histological examination of their pancreata provided no evidence of the large-scale GABAA-R agonist–mediated replenishment of islet β-cells that has been reported by others. However, we did observe a few functional islets in mice that received combined therapy. Thus, GABAA-R activation enhanced CD4+ and CD8+ regulatory T cell responses following the depletion of effector T cells, which was associated with the preservation of some functional islets. Finally, we observed that homotaurine treatment enhanced β-cell replication and survival in a human islet xenograft model. Hence, GABAA-R agonists, such as homotaurine, are attractive candidates for testing in combination with other therapeutic agents in type 1 diabetes clinical trials.
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Affiliation(s)
- Jide Tian
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Hoa Dang
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Karen Anne O'Laco
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Min Song
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Bryan-Clement Tiu
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Spencer Gilles
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Christina Zakarian
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Daniel L Kaufman
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
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29
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Wang Q, Ren L, Wan Y, Prud'homme GJ. GABAergic regulation of pancreatic islet cells: Physiology and antidiabetic effects. J Cell Physiol 2019; 234:14432-14444. [PMID: 30693506 DOI: 10.1002/jcp.28214] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/15/2019] [Indexed: 01/24/2023]
Abstract
Diabetes occurs when pancreatic β-cell death exceeds β-cell growth, which leads to loss of β-cell mass. An effective therapy must have two actions: promotion of β-cell replication and suppression of β-cell death. Previous studies have established an important role for γ-aminobutyric acid (GABA) in islet-cell hormone homeostasis, as well as the maintenance of the β-cell mass. GABA exerts paracrine actions on α cells in suppressing glucagon secretion, and it has autocrine actions on β cells that increase insulin secretion. Multiple studies have shown that GABA increases the mitotic rate of β cells. In mice, following β-cell depletion with streptozotocin, GABA therapy can restore the β-cell mass. Enhanced β-cell replication appears to depend on growth and survival pathways involving Akt activation. Some studies have also suggested that it induces transdifferentiation of α cells into β cells, but this has been disputed and requires further investigation. In addition to proliferative effects, GABA protects β cells against injury and markedly reduces their apoptosis under a variety of conditions. The antiapoptotic effects depend at least in part on the enhancement of sirtuin-1 and Klotho activity, which both inhibit activation of the NF-κB inflammatory pathway. Importantly, in xenotransplanted human islets, GABA therapy stimulates β-cell replication and insulin secretion. Thus, the intraislet GABAergic system is a target for the amelioration of diabetes therapy, including β-cell survival and regeneration. GABA (or GABAergic drugs) can be combined with other antidiabetic drugs for greater effect.
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Affiliation(s)
- Qinghua Wang
- Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical School, Fudan University, Shanghai, China.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.,Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Liwei Ren
- Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical School, Fudan University, Shanghai, China
| | - Yun Wan
- Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical School, Fudan University, Shanghai, China
| | - Gerald J Prud'homme
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine, St. Michael's Hospital, Toronto, Ontario, Canada
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30
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Jacobson DA, Shyng SL. Ion Channels of the Islets in Type 2 Diabetes. J Mol Biol 2019; 432:1326-1346. [PMID: 31473158 DOI: 10.1016/j.jmb.2019.08.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023]
Abstract
Ca2+ is an essential signal for pancreatic β-cell function. Ca2+ plays critical roles in numerous β-cell pathways such as insulin secretion, transcription, metabolism, endoplasmic reticulum function, and the stress response. Therefore, β-cell Ca2+ handling is tightly controlled. At the plasma membrane, Ca2+ entry primarily occurs through voltage-dependent Ca2+ channels. Voltage-dependent Ca2+ channel activity is dependent on orchestrated fluctuations in the plasma membrane potential or voltage, which are mediated via the activity of many ion channels. During the pathogenesis of type 2 diabetes the β-cell is exposed to stressful conditions, which result in alterations of Ca2+ handling. Some of the changes in β-cell Ca2+ handling that occur under stress result from perturbations in ion channel activity, expression or localization. Defective Ca2+ signaling in the diabetic β-cell alters function, limits insulin secretion and exacerbates hyperglycemia. In this review, we focus on the β-cell ion channels that control Ca2+ handling and how they impact β-cell dysfunction in type 2 diabetes.
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Affiliation(s)
- David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7415 MRB4 (Langford), 2213 Garland Avenue, Nashville, TN 37232, USA.
| | - Show-Ling Shyng
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, L224, MRB 624, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
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31
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Tu LL, Sun Q, Wei LL, Shi J, Li JP. Upregulation of GABA receptor promotes long-term potentiation and depotentiation in the hippocampal CA1 region of mice with type 2 diabetes mellitus. Exp Ther Med 2019; 18:2429-2436. [PMID: 31555354 PMCID: PMC6755275 DOI: 10.3892/etm.2019.7868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 04/18/2019] [Indexed: 12/13/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a long-term metabolic disorder characterized by high blood sugar levels, insulin resistance and a relative lack of insulin. A previous study has reported that an association exists between γ-aminobutyric acid (GABA) and the hippocampus. The current study therefore aimed to assess the effect of the GABA receptor (GABA-R) on the long-term potentiation (LTP) and depotentiation of the hippocampal CA1 region in mice with T2DM. Mice were divided into four groups: A normal group consisting of healthy mice and a GABA-R, negative control and blank group all comprising T2DM mice. The weight and blood glucose level of all mice were measured and GABA-R mRNA and protein expression were detected. A hydroxyl free radical (OH-) kit was used to determine the hippocampal OH-content. Using an electrophysiological experiment, the population spike (PS) slope was observed every 5 min. The results revealed that as GABA-R levels increased, the weight, blood glucose level and OH− content of the T2DM mice significantly decreased, and the neuron microstructures in the mice hippocampal tissue improved. The PS slope also significantly increased and the level of depotentiation improved. The results of the current study support the theory that the upregulation of GABA-R protects the neuronal ultrastructure and promotes LTP and depotentiation in the hippocampal CA1 region by inhibiting the accumulation of OH− in T2DM mice.
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Affiliation(s)
- Li-Li Tu
- Department of Geratology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, P.R. China
| | - Qin Sun
- Center of Diabetes Mellitus, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610000, P.R. China
| | - Ling-Ling Wei
- Center of Diabetes Mellitus, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610000, P.R. China
| | - Jing Shi
- Center of Diabetes Mellitus, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610000, P.R. China
| | - Jian-Ping Li
- Department of Geratology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, P.R. China
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32
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Thielen JW, Gancheva S, Hong D, Rohani Rankouhi S, Chen B, Apostolopoulou M, Anadol-Schmitz E, Roden M, Norris DG, Tendolkar I. Higher GABA concentration in the medial prefrontal cortex of Type 2 diabetes patients is associated with episodic memory dysfunction. Hum Brain Mapp 2019; 40:4287-4295. [PMID: 31264324 DOI: 10.1002/hbm.24702] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/18/2019] [Accepted: 06/18/2019] [Indexed: 01/05/2023] Open
Abstract
Type 2 diabetes (T2D) is associated with an accelerated episodic memory decline, but the underlying pathophysiological mechanisms are not well understood. Hallmarks of T2D comprise impairment of insulin secretion and insulin sensitivity. Insulin signaling modulates cerebral neurotransmitter activity, including the excitatory glutamate and inhibitory gamma-aminobutyric acid (GABA) systems. Here we tested the hypothesis that the glutamate and GABA systems are altered in T2D patients and this relates to memory decline and insulin resistance. Using 1 H-magnetic resonance spectroscopy (MRS), we examined glutamate and GABA concentrations in episodic memory relevant brain regions (medial prefrontal cortex and precuneus) of T2D patients and matched controls. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamps and memory performance was assessed using a face-profession associations test. T2D patients exhibited peripheral insulin resistance and had a decreased memory for face-profession associations as well as elevated GABA concentration in the medial prefrontal cortex but not precuneus. In addition, medial prefrontal cortex GABA concentration was negatively associated with memory performance suggesting that abnormal GABA levels in the medial prefrontal cortex are linked to the episodic memory decline that occurs in T2D patients.
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Affiliation(s)
- Jan-Willem Thielen
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany.,Donders Institute for Brain Cognition and Behavior, Radboud University and Radboud University Medical Center, Nijmegen, the Netherlands.,Department for Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Sofiya Gancheva
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany.,Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Donghyun Hong
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany
| | | | - Bixia Chen
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany
| | - Maria Apostolopoulou
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Evrim Anadol-Schmitz
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Michael Roden
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany.,Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - David G Norris
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany.,Donders Institute for Brain Cognition and Behavior, Radboud University and Radboud University Medical Center, Nijmegen, the Netherlands.,MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands
| | - Indira Tendolkar
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany.,Donders Institute for Brain Cognition and Behavior, Radboud University and Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Psychiatry, Radboud University Medical Center, Nijmegen, the Netherlands
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33
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Tse LH, Wong YH. GPCRs in Autocrine and Paracrine Regulations. Front Endocrinol (Lausanne) 2019; 10:428. [PMID: 31354618 PMCID: PMC6639758 DOI: 10.3389/fendo.2019.00428] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 06/14/2019] [Indexed: 12/17/2022] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest superfamily of integral membrane protein receptors. As signal detectors, the several 100 known GPCRs are responsible for sensing the plethora of endogenous ligands that are critical for the functioning of our endocrine system. Although GPCRs are typically considered as detectors for first messengers in classical signal transduction pathways, they seldom operate in isolation in complex biological systems. Intercellular communication between identical or different cell types is often mediated by autocrine or paracrine signals that are generated upon activation of specific GPCRs. In the context of energy homeostasis, the distinct complement of GPCRs in each cell type bridges the autocrine and paracrine communication within an organ, and the various downstream signaling mechanisms regulated by GPCRs can be integrated in a cell to produce an ultimate output. GPCRs thus act as gatekeepers that coordinate and fine-tune a response. By examining the role of GPCRs in activating and receiving autocrine and paracrine signals, one may have a better understanding of endocrine diseases that are associated with GPCR mutations, thereby providing new insights for treatment regimes.
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Affiliation(s)
- Lap Hang Tse
- Division of Life Science, Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, Hong Kong
| | - Yung Hou Wong
- Division of Life Science, Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, Hong Kong
- State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Hong Kong University of Science and Technology, Hong Kong, Hong Kong
- *Correspondence: Yung Hou Wong
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34
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Untereiner A, Abdo S, Bhattacharjee A, Gohil H, Pourasgari F, Ibeh N, Lai M, Batchuluun B, Wong A, Khuu N, Liu Y, Al Rijjal D, Winegarden N, Virtanen C, Orser BA, Cabrera O, Varga G, Rocheleau J, Dai FF, Wheeler MB. GABA promotes β-cell proliferation, but does not overcome impaired glucose homeostasis associated with diet-induced obesity. FASEB J 2018; 33:3968-3984. [PMID: 30509117 DOI: 10.1096/fj.201801397r] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
γ-Aminobutyric acid (GABA) administration has been shown to increase β-cell mass, leading to a reversal of type 1 diabetes in mice. Whether GABA has any effect on β cells of healthy and prediabetic/glucose-intolerant obese mice remains unknown. In the present study, we show that oral GABA administration ( ad libitum) to mice indeed increased pancreatic β-cell mass, which led to a modest enhancement in insulin secretion and glucose tolerance. However, GABA treatment did not further increase insulin-positive islet area in high fat diet-fed mice and was unable to prevent or reverse glucose intolerance and insulin resistance. Mechanistically, whether in vivo or in vitro, GABA treatment increased β-cell proliferation. In vitro, the effect was shown to be mediated via the GABAA receptor. Single-cell RNA sequencing analysis revealed that GABA preferentially up-regulated pathways linked to β-cell proliferation and simultaneously down-regulated those networks required for other processes, including insulin biosynthesis and metabolism. Interestingly, single-cell differential expression analysis revealed GABA treatment gave rise to a distinct subpopulation of β cells with a unique transcriptional signature, including urocortin 3 ( ucn3), wnt4, and hepacam2. Taken together, this study provides new mechanistic insight into the proliferative nature of GABA but suggests that β-cell compensation associated with prediabetes overlaps with, and negates, its proliferative effects.-Untereiner, A., Abdo, S., Bhattacharjee, A., Gohil, H., Pourasgari, F., Ibeh, N., Lai, M., Batchuluun, B., Wong, A., Khuu, N., Liu, Y., Al Rijjal, D., Winegarden, N., Virtanen, C., Orser, B. A., Cabrera, O., Varga, G., Rocheleau, J., Dai, F. F., Wheeler, M. B. GABA promotes β-cell proliferation, but does not overcome impaired glucose homeostasis associated with diet-induced obesity.
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Affiliation(s)
- Ashley Untereiner
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Shaaban Abdo
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Alpana Bhattacharjee
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Himaben Gohil
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | | | - Neke Ibeh
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Mi Lai
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | | | - Anthony Wong
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Nicholas Khuu
- Princess Margaret Genomics Centre, University Health Network, Toronto, Ontario, Canada
| | - Ying Liu
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Dana Al Rijjal
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Neil Winegarden
- Princess Margaret Genomics Centre, University Health Network, Toronto, Ontario, Canada
| | - Carl Virtanen
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Beverley A Orser
- Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada
| | - Over Cabrera
- Diabetes and Complications Research, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, USA
| | - Gabor Varga
- Diabetes and Complications Research, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, USA
| | - Jonathan Rocheleau
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Feihan F Dai
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Michael B Wheeler
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
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35
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Regeneration of Pancreatic β-Islet Cells in a Type-II Diabetic. Case Rep Endocrinol 2018; 2018:6147349. [PMID: 30254769 PMCID: PMC6145154 DOI: 10.1155/2018/6147349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/19/2018] [Indexed: 11/25/2022] Open
Abstract
A case report is presented in which a type-II diabetic patient significantly improved his dysfunctional β-islet cells using a combination of a strenuous exercise program, cyclical ketogenic diet, and oral GABA/probiotic supplementation. The patient was diagnosed with type-II diabetes at the age of 41 which then progressed through a typical series of treatment changes over 14 years. Treatment periods consisted of metformin therapy alone for 4 years followed by a metformin/glyburide combination therapy for 6 years, and eventually an insulin/metformin combination therapy for 4 years. One year after the initiation of insulin, the patient increased the level of strenuous physical activity (hiking and weight lifting) and adopted a ketogenic diet. Oral GABA and probiotic supplementation were also initiated at the age of 52.7. By the age of 55, the patient no longer required any insulin and is currently being managed with metformin alone. C-peptide values indicate a functional improvement of the β-islet cells during the time of insulin/GABA/probiotic treatment.
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36
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Tang X, Yu R, Zhou Q, Jiang S, Le G. Protective effects of γ-aminobutyric acid against H 2O 2-induced oxidative stress in RIN-m5F pancreatic cells. Nutr Metab (Lond) 2018; 15:60. [PMID: 30202421 PMCID: PMC6122738 DOI: 10.1186/s12986-018-0299-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/26/2018] [Indexed: 11/30/2022] Open
Abstract
Background γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system and reported to maintain the redox homeostasis and insulin secretion function of pancreatic β cells. This study tested the hypothesis that GABA maintains cellular redox status, and modulates glycogen synthase kinase (GSK)-3β and antioxidant-related nuclear factor erythroid 2-related factor 2 (NRF2) nuclear mass ratio in the H2O2-injured RINm5F cells. Methods RINm5F cells were treated with/without GABA (50, 100 and 200 μmol/L) for 48 h and then exposed to 100 μmol/L H2O2 for 30 min. Viable cells were harvested, and dichloro-dihydro-fluorescein diacetate (DCFH-DA) was used to detect reactive oxygen species (ROS) level; cellular redox status and insulin secretion were measured; cell viability was determined by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay; mitochondrial membrane potential (MMP) was detected by flow cytometry; relative genes levels were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR); western blotting was used to determine protein expression of GSK-3β and p-GSK-3β (Ser9), and nuclear and cytoplasmic NRF2. Results H2O2 increased ROS production, and induced adverse affects in relation to antioxidant defense systems and insulin secretion. These changes were restored by treatment with 100 and 200 μmol/L GABA. In addition, 100 or 200 μmol/L GABA induced membrane depolarization and increased cell viability. These effects were mediated by Caspase-3, Bcl-2 associated X protein (Bax) and B-cell lymphoma-2 (Bcl-2) expression. Western blotting indicated that GABA inhibited GSK-3β by increasing p-GSK-3β (Ser9) level, and directed the transcription factor NRF2 to the nucleus. Conclusion In rat insulin-producing RINm5F cells, GABA exerts its protective effect by regulating GSK-3β and NRF2, which governs redox homeostasis by inhibiting apoptosis and abnormal insulin secretion by exposure to H2O2.
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Affiliation(s)
- Xue Tang
- 1State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China.,3School of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China
| | - Renqiang Yu
- 2The Affiliated Wuxi Maternity and Child Health Care Hospital of Nanjing Medical University, Wuxi, 214002 Jiangsu China
| | - Qin Zhou
- 2The Affiliated Wuxi Maternity and Child Health Care Hospital of Nanjing Medical University, Wuxi, 214002 Jiangsu China
| | - Shanyu Jiang
- 2The Affiliated Wuxi Maternity and Child Health Care Hospital of Nanjing Medical University, Wuxi, 214002 Jiangsu China
| | - Guowei Le
- 1State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China.,3School of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China
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Functional Characterization of Native, High-Affinity GABA A Receptors in Human Pancreatic β Cells. EBioMedicine 2018; 30:273-282. [PMID: 29606630 PMCID: PMC5952339 DOI: 10.1016/j.ebiom.2018.03.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 02/02/2018] [Accepted: 03/12/2018] [Indexed: 01/19/2023] Open
Abstract
In human pancreatic islets, the neurotransmitter γ-aminobutyric acid (GABA) is an extracellular signaling molecule synthesized by and released from the insulin-secreting β cells. The effective, physiological GABA concentration range within human islets is unknown. Here we use native GABAA receptors in human islet β cells as biological sensors and reveal that 100–1000 nM GABA elicit the maximal opening frequency of the single-channels. In saturating GABA, the channels desensitized and stopped working. GABA modulated insulin exocytosis and glucose-stimulated insulin secretion. GABAA receptor currents were enhanced by the benzodiazepine diazepam, the anesthetic propofol and the incretin glucagon-like peptide-1 (GLP-1) but not affected by the hypnotic zolpidem. In type 2 diabetes (T2D) islets, single-channel analysis revealed higher GABA affinity of the receptors. The findings reveal unique GABAA receptors signaling in human islets β cells that is GABA concentration-dependent, differentially regulated by drugs, modulates insulin secretion and is altered in T2D. In human islets GABA (≤μM) activates β cell-specific GABAA receptors that become supersensitive to GABA in type 2 diabetes. GABAA receptors activity in β cells is enhanced by diazepam, anesthetics, the incretin GLP-1 but not the hypnotic zolpidem. GABA modulates rate of insulin granule exocytosis and glucose-stimulated insulin secretion.
GABA is a signal molecule in the brain but is also secreted by the insulin-producing β cells in pancreatic islets. GABA has many roles in human islets that most aim at optimizing function and survival of β cells. In the report by Korol, Jin et al. the authors identify and characterize the molecular unit that GABA binds to in human β cells, the GABAA receptors. These receptors normally sensitive become super-sensitive to GABA in type 2 diabetes. The GABAA receptors regulate insulin secretion and can themselves be regulated by the anxiolytic diazepam, anesthetics, the incretin GLP-1 but not the hypnotic zolpidem. Targeting GABA signaling in human islets in diabetes mellitus is likely to be a part of the solution when curing diabetes.
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Effects of GABAB receptor activation on spatial cognitive function and hippocampal neurones in rat models of type 2 diabetes mellitus. Biosci Rep 2018; 38:BSR20171184. [PMID: 29176000 PMCID: PMC5773821 DOI: 10.1042/bsr20171184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/17/2017] [Accepted: 11/22/2017] [Indexed: 12/13/2022] Open
Abstract
The present study was conducted with the aim being to investigate the effect γ-aminobutyric acid type B (GABAB) receptor activation have on spatial cognitive function and hippocampal neurones found in the rat models of type 2 diabetes mellitus (T2DM). T2DM rat models were then established, randomized, and subsequently assigned into normal control (NC), T2DM, T2DM + chemical grade propylene (CGP), T2DM + baclofen, and T2DM + CGP + baclofen groups. T2DM rats’ weight and blood sugar concentrations were monitored. The DMS-2 Morris water maze testing system was performed in order to figure out the spatial cognitive function of these rats. Reverse-transcription quantitative PCR (RT-qPCR) and Western blotting were also performed in order to detect GABAB mRNA and protein expressions. We used the Nissl staining method in order to detect the number of hippocampal neurones, TUNEL (terminal deoxyribonucleotidy transferase-mediated dUTP nick labeling) staining to detect cell apoptosis, and Western blotting method in order to measure the expressions of the apoptosis-related proteins (Bax, cytochrome c (Cyt-c), Caspase-3, and Bcl-2). In comparison with the T2DM group, the weight decreased, blood sugar concentration increased, and spatial cognitive function as well as hippocampal neurones were both impaired in the T2DM + CGP group, contrary to the rats in the T2DM + baclofen group who showed an opposite trend. The situation in the T2DM + CGP + baclofen group was better than that found in the T2DM + CGP group while proving to be more serious than that of the NC and T2DM + baclofen groups. Conclusively, activating the GABAB receptor improved spatial cognitive function and hippocampal neurones in the T2DM rats.
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Characterization of a Potential Probiotic Lactobacillus brevis RK03 and Efficient Production of γ-Aminobutyric Acid in Batch Fermentation. Int J Mol Sci 2018; 19:ijms19010143. [PMID: 29300336 PMCID: PMC5796092 DOI: 10.3390/ijms19010143] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 12/24/2017] [Accepted: 01/03/2018] [Indexed: 12/26/2022] Open
Abstract
Lactic acid bacteria were isolated from fish and evaluated for their γ-aminobutyric acid (GABA)-producing abilities. Out of thirty-two isolates, Lactobacillus brevis RK03 showed the highest GABA production ability. The effects of various fermentation parameters including initial glutamic acid level, culture temperature, initial pH, and incubation time on GABA production were investigated via a singleparameter optimization strategy. For industrial large-scale production, a low-cost GABA producing medium (GM) broth was developed for fermentation with L. brevis RK03. We found that an optimized GM broth recipe of 1% glucose; 2.5% yeast extract; 2 ppm each of CaCO₃, MnSO₄, and Tween 80; and 10 μM pyridoxal phosphate (PLP) resulted in a maximum GABA yield of 62,523 mg/L after 88 h following the addition of 650 mM monosodium glutamate (MSG), for a conversion rate of 93.28%. Our data provide a practical approach for the highly efficient and economic production of GABA. In addition, L. brevis RK03 is highly resistant to gastric acid and bovine bile salt. Thus, the discovery of Lactobacillus strains with the ability to synthesize GABA may offer new opportunities in the design of improved health-promoting functional foods.
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Rorsman P, Ashcroft FM. Pancreatic β-Cell Electrical Activity and Insulin Secretion: Of Mice and Men. Physiol Rev 2018; 98:117-214. [PMID: 29212789 PMCID: PMC5866358 DOI: 10.1152/physrev.00008.2017] [Citation(s) in RCA: 421] [Impact Index Per Article: 70.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/30/2017] [Accepted: 06/18/2017] [Indexed: 12/14/2022] Open
Abstract
The pancreatic β-cell plays a key role in glucose homeostasis by secreting insulin, the only hormone capable of lowering the blood glucose concentration. Impaired insulin secretion results in the chronic hyperglycemia that characterizes type 2 diabetes (T2DM), which currently afflicts >450 million people worldwide. The healthy β-cell acts as a glucose sensor matching its output to the circulating glucose concentration. It does so via metabolically induced changes in electrical activity, which culminate in an increase in the cytoplasmic Ca2+ concentration and initiation of Ca2+-dependent exocytosis of insulin-containing secretory granules. Here, we review recent advances in our understanding of the β-cell transcriptome, electrical activity, and insulin exocytosis. We highlight salient differences between mouse and human β-cells, provide models of how the different ion channels contribute to their electrical activity and insulin secretion, and conclude by discussing how these processes become perturbed in T2DM.
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Affiliation(s)
- Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Frances M Ashcroft
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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Indrowati M, Pratiwi R, Rumiyati, Astuti P. Levels of Blood Glucose and Insulin Expression of Beta-cells in Streptozotocin-induced Diabetic Rats Treated with Ethanolic Extract of Artocarpus altilis Leaves and GABA. Pak J Biol Sci 2017; 20:28-35. [PMID: 29023012 DOI: 10.3923/pjbs.2017.28.35] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND OBJECTIVE Information about the Artocarpus altilis leaf as an antidiabetic associated with the active compounds Gamma Amino Butyric Acid (GABA) is still limited. This study was conducted to determine the effects of ethanolic extract of A. altilis leaves decoction and GABA on blood glucose levels and insulin expression of beta-cells in streptozotocin-induced diabetic rats. MATERIAL AND METHODS This study was done by using completely randomized design and male Sprague Dewley rats. The rats were devided into normal control group and diabetic rats groups. Levels of bood glucose were measured using strip rapid test. The insulin expression in beta-cells was assessed using immunohistochemistry. Quantitative data were analyzed using ANOVA at 5% confidence level. RESULTS The result indicated that 50 mg k-1 b.wt., GABA, 400 and 800 mg k-1 b.wt., ethanolic extract of A. altilis leaves decreased the level of blood glucose and increased the insulin expression in pancreas beta-cells. CONCLUSION The GABA and ethanolic extract of A. altilis leaves with a minimum dose of 400 mg k-1 b.wt., can be used as an antidiabetic. Pancreas is the target organ was affected by GABA and A. altilis leaves as antidiabetic agents. Results of this study may support the development of research on the potency of GABA in natural materials as antidiabetic particularly type 1 diabetes.
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Affiliation(s)
- Meti Indrowati
- Department of Biological Education, Faculty of Teacher Training and Education, Universitas Sebelas Maret, Jalan Ir. Sutami 36A 57126, Surakarta, Indonesia
| | - Rarastoeti Pratiwi
- Faculty of Biology, Universitas Gadjah Mada, Jalan Te knika Selatan Sekip Utara, 55281 Yogyakarta, Indonesia
| | - Rumiyati
- Faculty of Pharmacy, Universitas Gadj ah Mada, 55281 Yogyakarta, Indonesia
| | - Pudji Astuti
- Faculty of Veterinary Medicine, Universitas Gadjah Mada, Jalan Fauna No. 2, Karangmalang, 55281 Yogyakarta, Indonesia
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Hsueh YH, Liaw WC, Kuo JM, Deng CS, Wu CH. Hydrogel Film-Immobilized Lactobacillus brevis RK03 for γ-Aminobutyric Acid Production. Int J Mol Sci 2017. [PMID: 29099794 DOI: 10.3390/ijms18n2324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
Hydrogels of 2-hydroxyethyl methacrylate/polyethylene glycol diacrylate (HEMA/PEGDA) have been extensively studied for their use in biomedical and pharmaceutical applications owing to their nontoxic and highly hydrophilic characteristics. Recently, cells immobilized by HEMA/PEGDA hydrogels have also been studied for enhanced production in fermentation. Hydrogel films of HEMA/PEGDA copolymer were generated by Ultraviolet (UV)-initiated photopolymerization. The hydrogel films were used to immobilize viable Lactobacillus brevis RK03 cells for the bioconversion of monosodium glutamate (MSG) to γ-aminobutyric acid (GABA). The mechanical properties and fermentation yields of the L. brevis RK03 cells immobilized on polyacrylate hydrogel films with different monomeric formulations were investigated. Fermentation was carried out in 75 mL de Man, Rogosa and Sharpe (MRS) medium containing various concentrations of MSG. We found that HEMA (93%)/PEGDA (3%) hydrogels (sample H) maximized GABA production. The conversion rate of MSG to GABA reached a maximum value of 98.4% after 240 h. Bioconversion activity gradually declined after 420 h to 83.8% after five cycles of semi-continuous fermentation. Our results suggest that HEMA (93%)/PEGDA (3%) hydrogels have great potential for use in GABA production via semi-continuous fermentation.
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Affiliation(s)
- Yi-Huang Hsueh
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan City 32003, Taiwan.
| | - Wen-Chang Liaw
- Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin City 64002, Taiwan.
| | - Jen-Min Kuo
- Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung City 81157, Taiwan.
| | - Chi-Shin Deng
- Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin City 64002, Taiwan.
| | - Chien-Hui Wu
- Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung City 81157, Taiwan.
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Hydrogel Film-Immobilized Lactobacillus brevis RK03 for γ-Aminobutyric Acid Production. Int J Mol Sci 2017; 18:ijms18112324. [PMID: 29099794 PMCID: PMC5713293 DOI: 10.3390/ijms18112324] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 10/26/2017] [Accepted: 10/31/2017] [Indexed: 12/27/2022] Open
Abstract
Hydrogels of 2-hydroxyethyl methacrylate/polyethylene glycol diacrylate (HEMA/PEGDA) have been extensively studied for their use in biomedical and pharmaceutical applications owing to their nontoxic and highly hydrophilic characteristics. Recently, cells immobilized by HEMA/PEGDA hydrogels have also been studied for enhanced production in fermentation. Hydrogel films of HEMA/PEGDA copolymer were generated by Ultraviolet (UV)-initiated photopolymerization. The hydrogel films were used to immobilize viable Lactobacillus brevis RK03 cells for the bioconversion of monosodium glutamate (MSG) to γ-aminobutyric acid (GABA). The mechanical properties and fermentation yields of the L. brevis RK03 cells immobilized on polyacrylate hydrogel films with different monomeric formulations were investigated. Fermentation was carried out in 75 mL de Man, Rogosa and Sharpe (MRS) medium containing various concentrations of MSG. We found that HEMA (93%)/PEGDA (3%) hydrogels (sample H) maximized GABA production. The conversion rate of MSG to GABA reached a maximum value of 98.4% after 240 h. Bioconversion activity gradually declined after 420 h to 83.8% after five cycles of semi-continuous fermentation. Our results suggest that HEMA (93%)/PEGDA (3%) hydrogels have great potential for use in GABA production via semi-continuous fermentation.
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Skelin Klemen M, Dolenšek J, Slak Rupnik M, Stožer A. The triggering pathway to insulin secretion: Functional similarities and differences between the human and the mouse β cells and their translational relevance. Islets 2017; 9:109-139. [PMID: 28662366 PMCID: PMC5710702 DOI: 10.1080/19382014.2017.1342022] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In β cells, stimulation by metabolic, hormonal, neuronal, and pharmacological factors is coupled to secretion of insulin through different intracellular signaling pathways. Our knowledge about the molecular machinery supporting these pathways and the patterns of signals it generates comes mostly from rodent models, especially the laboratory mouse. The increased availability of human islets for research during the last few decades has yielded new insights into the specifics in signaling pathways leading to insulin secretion in humans. In this review, we follow the most central triggering pathway to insulin secretion from its very beginning when glucose enters the β cell to the calcium oscillations it produces to trigger fusion of insulin containing granules with the plasma membrane. Along the way, we describe the crucial building blocks that contribute to the flow of information and focus on their functional role in mice and humans and on their translational implications.
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Affiliation(s)
- Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Institute of Physiology; Center for Physiology and Pharmacology; Medical University of Vienna; Vienna, Austria
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
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Aggarwal S, Ahuja V, Paul J. Attenuated GABAergic Signaling in Intestinal Epithelium Contributes to Pathogenesis of Ulcerative Colitis. Dig Dis Sci 2017; 62:2768-2779. [PMID: 28667430 DOI: 10.1007/s10620-017-4662-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/21/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Neuromediators produced by enteric nervous system regulate inflammatory processes via interacting with enteric immune system. Role of γ-aminobutyric acid (GABA), which is also a neuromediator, has been implicated in autoimmune diseases like multiple sclerosis, type 1 diabetes, and rheumatoid arthritis, where they modulate the immune responses. However, its role in ulcerative colitis (UC) has not been defined. AIMS This study was carried out to investigate the role of GABA and its signaling components in pathogenesis of UC. METHODS Peripheral blood, colon mucosal biopsy, and fecal specimens were collected from UC and control groups. Quantification of GABA was done using ELISA. Expression of GABAergic signal system components was analyzed through RT-PCR analysis. Enumeration of GABA-producing bacteria was done by qPCR analysis. Activity of p38 MAPK and expression of proinflammatory cytokines were determined by immunohistochemistry and RT-PCR analysis, respectively. RESULTS GABA levels were significantly reduced in patients with UC as compared to control group when measured in serum and colon biopsy. Altered expression of GABAergic signal system was observed in UC patients. Reduced abundance of selected GABA-producing bacteria was detected in stool samples of UC patients as compared to control. p38 MAPK activity and expression of its downstream effector cytokines were found to be increased in UC patients as compared to control. CONCLUSIONS Reduced levels of GABA were observed in patients with UC, and this leads to hyperactivation of p38 MAPK and overexpression of downstream effector cytokines suggesting a role of GABA in pathogenesis of UC.
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Affiliation(s)
- Surbhi Aggarwal
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Vineet Ahuja
- Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi, 110067, India
| | - Jaishree Paul
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Insulin, glucagon and somatostatin stores in the pancreas of subjects with type-2 diabetes and their lean and obese non-diabetic controls. Sci Rep 2017; 7:11015. [PMID: 28887444 PMCID: PMC5591190 DOI: 10.1038/s41598-017-10296-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/20/2017] [Indexed: 12/14/2022] Open
Abstract
In type-2 diabetes, both insufficient insulin and excessive glucagon secretion contribute to hyperglycemia. We compared insulin, glucagon and somatostatin stores in pancreas obtained at autopsy of 20 lean and 19 obese non-diabetic (ND), and 18 type-2 diabetic (T2D) subjects. From concentrations and pancreas weight, total content of hormones was calculated. Insulin content was 35% lower in T2D than ND subjects (7.4 versus 11.3 mg), whereas glucagon content was similar (0.76 versus 0.81 mg). The higher ratio of glucagon/insulin contents in T2D was thus explained by the decrease in insulin. With increasing BMI of ND subjects, insulin and glucagon contents respectively tended to increase and decrease, resulting in a lower glucagon/insulin ratio in obesity. With aging, insulin and glucagon contents did not significantly change in ND subjects but declined in T2D subjects, without association with the duration of diabetes or type of treatment. The somatostatin content was lower in T2D than ND subjects (0.027 versus 0.038 mg), but ratios somatostatin/insulin and somatostatin/glucagon were not different. In conclusion, insulin stores are about 1/3 lower in T2D than ND subjects, whereas glucagon stores are unchanged. Abnormal secretion of each hormone in type-2 diabetes cannot be attributed to major alterations in their pancreatic reserves.
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Kursan S, McMillen TS, Beesetty P, Dias-Junior E, Almutairi MM, Sajib AA, Kozak JA, Aguilar-Bryan L, Di Fulvio M. The neuronal K +Cl - co-transporter 2 (Slc12a5) modulates insulin secretion. Sci Rep 2017; 7:1732. [PMID: 28496181 PMCID: PMC5431760 DOI: 10.1038/s41598-017-01814-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 04/03/2017] [Indexed: 11/09/2022] Open
Abstract
Intracellular chloride concentration ([Cl-]i) in pancreatic β-cells is kept above electrochemical equilibrium due to the predominant functional presence of Cl- loaders such as the Na+K+2Cl- co-transporter 1 (Slc12a2) over Cl-extruders of unidentified nature. Using molecular cloning, RT-PCR, Western blotting, immunolocalization and in vitro functional assays, we establish that the "neuron-specific" K+Cl- co-transporter 2 (KCC2, Slc12a5) is expressed in several endocrine cells of the pancreatic islet, including glucagon secreting α-cells, but particularly in insulin-secreting β-cells, where we provide evidence for its role in the insulin secretory response. Three KCC2 splice variants were identified: the formerly described KCC2a and KCC2b along with a novel one lacking exon 25 (KCC2a-S25). This new variant is undetectable in brain or spinal cord, the only and most abundant known sources of KCC2. Inhibition of KCC2 activity in clonal MIN6 β-cells increases basal and glucose-stimulated insulin secretion and Ca2+ uptake in the presence of glibenclamide, an inhibitor of the ATP-dependent potassium (KATP)-channels, thus suggesting a possible mechanism underlying KCC2-dependent insulin release. We propose that the long-time considered "neuron-specific" KCC2 co-transporter is expressed in pancreatic islet β-cells where it modulates Ca2+-dependent insulin secretion.
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Affiliation(s)
- Shams Kursan
- Department of Pharmacology and Toxicology, Wright State University, School of Medicine, Dayton, OH, 45435, USA
| | | | - Pavani Beesetty
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, School of Medicine, Dayton, OH, 45435, USA
| | - Eduardo Dias-Junior
- Department of Pharmacology and Toxicology, Wright State University, School of Medicine, Dayton, OH, 45435, USA
| | - Mohammed M Almutairi
- Department of Pharmacology and Toxicology, Wright State University, School of Medicine, Dayton, OH, 45435, USA
| | - Abu A Sajib
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh
| | - J Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, School of Medicine, Dayton, OH, 45435, USA
| | | | - Mauricio Di Fulvio
- Department of Pharmacology and Toxicology, Wright State University, School of Medicine, Dayton, OH, 45435, USA.
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Bai X, Fu S. GetArtemisininsByAnymeans (GABA): artemisinins path to conquer diabetes go through GABA receptors. Sci Bull (Beijing) 2017; 62:383-385. [PMID: 36659279 DOI: 10.1016/j.scib.2017.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Xiaojie Bai
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Suneng Fu
- School of Life Sciences, Tsinghua University, Beijing 100084, China.
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Tian J, Dang H, Hu A, Xu W, Kaufman DL. Repurposing Lesogaberan to Promote Human Islet Cell Survival and β-Cell Replication. J Diabetes Res 2017; 2017:6403539. [PMID: 29018828 PMCID: PMC5605788 DOI: 10.1155/2017/6403539] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/26/2017] [Indexed: 12/15/2022] Open
Abstract
The activation of β-cell's A- and B-type gamma-aminobutyric acid receptors (GABAA-Rs and GABAB-Rs) can promote their survival and replication, and the activation of α-cell GABAA-Rs promotes their conversion into β-cells. However, GABA and the most clinically applicable GABA-R ligands may be suboptimal for the long-term treatment of diabetes due to their pharmacological properties or potential side-effects on the central nervous system (CNS). Lesogaberan (AZD3355) is a peripherally restricted high-affinity GABAB-R-specific agonist, originally developed for the treatment of gastroesophageal reflux disease (GERD) that appears to be safe for human use. This study tested the hypothesis that lesogaberan could be repurposed to promote human islet cell survival and β-cell replication. Treatment with lesogaberan significantly enhanced replication of human islet cells in vitro, which was abrogated by a GABAB-R antagonist. Immunohistochemical analysis of human islets that were grafted into immune-deficient mice revealed that oral treatment with lesogaberan promoted human β-cell replication and islet cell survival in vivo as effectively as GABA (which activates both GABAA-Rs and GABAB-Rs), perhaps because of its more favorable pharmacokinetics. Lesogaberan may be a promising drug candidate for clinical studies of diabetes intervention and islet transplantation.
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Affiliation(s)
- Jide Tian
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, USA
| | - Hoa Dang
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, USA
| | - Angela Hu
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, USA
| | - Willem Xu
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, USA
| | - Daniel L. Kaufman
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA, USA
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Patterson E, Ryan PM, Cryan JF, Dinan TG, Ross RP, Fitzgerald GF, Stanton C. Gut microbiota, obesity and diabetes. Postgrad Med J 2016; 92:286-300. [PMID: 26912499 DOI: 10.1136/postgradmedj-2015-133285] [Citation(s) in RCA: 302] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/28/2016] [Indexed: 02/06/2023]
Abstract
The central role of the intestinal microbiota in the progression and, equally, prevention of metabolic dysfunction is becoming abundantly apparent. The symbiotic relationship between intestinal microbiota and host ensures appropriate development of the metabolic system in humans. However, disturbances in composition and, in turn, functionality of the intestinal microbiota can disrupt gut barrier function, a trip switch for metabolic endotoxemia. This low-grade chronic inflammation, brought about by the influx of inflammatory bacterial fragments into circulation through a malfunctioning gut barrier, has considerable knock-on effects for host adiposity and insulin resistance. Conversely, recent evidence suggests that there are certain bacterial species that may interact with host metabolism through metabolite-mediated stimulation of enteric hormones and other systems outside of the gastrointestinal tract, such as the endocannabinoid system. When the abundance of these keystone species begins to decline, we see a collapse of the symbiosis, reflected in a deterioration of host metabolic health. This review will investigate the intricate axis between the microbiota and host metabolism, while also addressing the promising and novel field of probiotics as metabolic therapies.
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Affiliation(s)
- Elaine Patterson
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Food Biosciences Department, Teagasc Food Research Centre, Fermoy, Co. Cork, Ireland
| | - Paul M Ryan
- Food Biosciences Department, Teagasc Food Research Centre, Fermoy, Co. Cork, Ireland School of Microbiology, University College Cork, Co. Cork, Ireland
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Department of Anatomy and Neuroscience, University College Cork, Co. Cork, Ireland
| | - Timothy G Dinan
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Department of Psychiatry and Neurobehavioural Science, University College Cork, Co. Cork, Ireland
| | - R Paul Ross
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland College of Science, Engineering and Food Science, University College Cork, Co. Cork, Ireland
| | - Gerald F Fitzgerald
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland School of Microbiology, University College Cork, Co. Cork, Ireland
| | - Catherine Stanton
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Food Biosciences Department, Teagasc Food Research Centre, Fermoy, Co. Cork, Ireland
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