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Kumrungsee T. Is hepatic GABA transaminase a promising target for obesity and epilepsy treatments? Biosci Biotechnol Biochem 2024; 88:839-849. [PMID: 38749549 DOI: 10.1093/bbb/zbae066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 05/05/2024] [Indexed: 07/23/2024]
Abstract
γ-Aminobutyric acid (GABA) transaminase (GABA-T) is a GABA-degrading enzyme that plays an essential role in regulating GABA levels and maintaining supplies of GABA. Although GABA in the mammalian brain was discovered 70 years ago, research on GABA and GABA-T has predominantly focused on the brain. Notwithstanding the high activity and expression of GABA-T in the liver, the exact functions of GABA-T in the liver remain unknown. This article reviews the up-to-date information on GABA-T in the liver. It presents recent findings on the role of liver GABA-T in food intake suppression and appetite regulation. Finally, the potential functions of liver GABA-T in other neurological diseases, natural GABA-T inhibitors, and future perspectives in this research area are discussed.
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Affiliation(s)
- Thanutchaporn Kumrungsee
- Program of Food and AgriLife Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
- Smart Agriculture, Graduate School of Innovation and Practice for Smart Society, Hiroshima University, Hiroshima, Japan
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Orser BA. Discovering the Intriguing Properties of Extrasynaptic γ-Aminobutyric Acid Type A Receptors. Anesthesiology 2024; 140:1192-1200. [PMID: 38624275 DOI: 10.1097/aln.0000000000004949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Tonic inhibition in mouse hippocampal CA1 pyramidal neurons is mediated by α5 subunit-containing γ-aminobutyric acid type A receptors. By Caraiscos VB, Elliott EM, You-Ten KE, Cheng VY, Belelli D, Newell JG, Jackson MF, Lambert JJ, Rosahl TW, Wafford KA, MacDonald JF, Orser BA. Proc Natl Acad Sci U S A 2004; 101:3662-7. Reprinted with permission. In this Classic Paper Revisited, the author recounts the scientific journey leading to a report published in the Proceedings of the National Academy of Sciences (PNAS) and shares several personal stories from her formative years and "research truths" that she has learned along the way. Briefly, the principal inhibitory neurotransmitter in the brain, γ-aminobutyric acid (GABA), was conventionally thought to regulate cognitive processes by activating synaptic GABA type A (GABAA) receptors and generating transient inhibitory synaptic currents. However, the author's laboratory team discovered a novel nonsynaptic form of tonic inhibition in hippocampal pyramidal neurons, mediated by extrasynaptic GABAA receptors that are pharmacologically distinct from synaptic GABAA receptors. This tonic current is highly sensitive to most general anesthetics, including sevoflurane and propofol, and likely contributes to the memory-blocking properties of these drugs. Before the publication in PNAS, the subunit composition of GABAA receptors that generate the tonic current was unknown. The team's research showed that GABAA receptors containing the α5 subunit (α5GABAARs) generated the tonic inhibitory current in hippocampal neurons. α5GABAARs are highly sensitive to GABA, desensitize slowly, and are thus well suited for detecting low, persistent, ambient concentrations of GABA in the extracellular space. Interest in α5GABAARs has surged since the PNAS report, driven by their pivotal roles in cognitive processes and their potential as therapeutic targets for treating various neurologic disorders.
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Affiliation(s)
- Beverley A Orser
- Department of Anesthesiology and Pain Medicine, and Department of Physiology, University of Toronto, Toronto, Canada
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Colucci Cante R, Nigro F, Passannanti F, Lentini G, Gallo M, Nigro R, Budelli AL. Gut health benefits and associated systemic effects provided by functional components from the fermentation of natural matrices. Compr Rev Food Sci Food Saf 2024; 23:e13356. [PMID: 38767859 DOI: 10.1111/1541-4337.13356] [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: 10/09/2023] [Revised: 02/26/2024] [Accepted: 04/06/2024] [Indexed: 05/22/2024]
Abstract
Recently, the role of the gut microbiota in metabolic health, immunity, behavioral balance, longevity, and intestine comfort has been the object of several studies from scientific communities. They were encouraged by a growing interest from food industries and consumers toward novel fermented ingredients and formulations with powerful biological effects, such as pre, pro, and postbiotic products. Depending on the selected strains, the operating conditions, the addition of suitable reagents or enzymes, the equipment, and the reactor configurations, functional compounds with high bioactivity, such as short-chain fatty acids, gamma-aminobutyric acid, bioactive peptides, and serotonin, can be enhanced and/or produced through fermentation of several vegetable matrices. Otherwise, their formation can also be promoted directly in the gut after the dietary intake of fermented foods: In this case, fermentation will aim to increase the content of precursor substances, such as indigestible fibers, polyphenols, some amino acids, and resistant starch, which can be potentially metabolized by endogenous gut microorganisms and converted in healthy molecules. This review provides an overview of the main functional components currently investigated in literature and the associated gut health benefits. The current state of the art about fermentation technology as a promising functionalization tool to promote the direct or indirect formation of gut-health-enhancing components was deepened, highlighting the importance of optimizing microorganism selection, system setups, and process conditions according to the target compound of interest. The collected data suggested the possibility of gaining novel functional food ingredients or products rich in functional molecules through fermentation without performing additional extraction and purification stages, which are needed when conventional culture broths are used.
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Affiliation(s)
- Rosa Colucci Cante
- Department of Chemical Engineering, Materials, and Industrial Production, University of Naples Federico II, Naples, Italy
- Department of Industrial Engineering, University of Niccolò Cusano, Rome, Italy
| | - Federica Nigro
- I. T. P. Innovation and Technology Provider S.r.l., Naples, Italy
| | - Francesca Passannanti
- Department of Chemical Engineering, Materials, and Industrial Production, University of Naples Federico II, Naples, Italy
- I. T. P. Innovation and Technology Provider S.r.l., Naples, Italy
| | - Giulia Lentini
- Department of Chemical Engineering, Materials, and Industrial Production, University of Naples Federico II, Naples, Italy
| | - Marianna Gallo
- Department of Chemical Engineering, Materials, and Industrial Production, University of Naples Federico II, Naples, Italy
- Department of Industrial Engineering, University of Niccolò Cusano, Rome, Italy
- I. T. P. Innovation and Technology Provider S.r.l., Naples, Italy
| | - Roberto Nigro
- Department of Chemical Engineering, Materials, and Industrial Production, University of Naples Federico II, Naples, Italy
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Choi J, Cayabyab F, Perez H, Yoshihara E. Scaling Insulin-Producing Cells by Multiple Strategies. Endocrinol Metab (Seoul) 2024; 39:191-205. [PMID: 38572534 PMCID: PMC11066437 DOI: 10.3803/enm.2023.1910] [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: 12/27/2023] [Revised: 01/20/2024] [Accepted: 01/30/2024] [Indexed: 04/05/2024] Open
Abstract
In the quest to combat insulin-dependent diabetes mellitus (IDDM), allogenic pancreatic islet cell therapy sourced from deceased donors represents a significant therapeutic advance. However, the applicability of this approach is hampered by donor scarcity and the demand for sustained immunosuppression. Human induced pluripotent stem cells are a game-changing resource for generating synthetic functional insulin-producing β cells. In addition, novel methodologies allow the direct expansion of pancreatic progenitors and mature β cells, thereby circumventing prolonged differentiation. Nevertheless, achieving practical reproducibility and scalability presents a substantial challenge for this technology. As these innovative approaches become more prominent, it is crucial to thoroughly evaluate existing expansion techniques with an emphasis on their optimization and scalability. This manuscript delineates these cutting-edge advancements, offers a critical analysis of the prevailing strategies, and underscores pivotal challenges, including cost-efficiency and logistical issues. Our insights provide a roadmap, elucidating both the promises and the imperatives in harnessing the potential of these cellular therapies for IDDM.
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Affiliation(s)
- Jinhyuk Choi
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Fritz Cayabyab
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Harvey Perez
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Eiji Yoshihara
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
- David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
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Ma S, Li J, Ye H, Huang S, Huang Z, Wu D, Ma K, Xie J, Yin Y, Tan C. Effects of dietary supplementation of different levels of gamma-aminobutyric acid on reproductive performance, glucose intolerance, and placental development of gilts. J Anim Sci 2024; 102:skad405. [PMID: 38133610 PMCID: PMC10781436 DOI: 10.1093/jas/skad405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
This study aimed to investigate the effects of dietary gamma-aminobutyric acid (GABA) supplementation on reproductive performance, glucose intolerance, and placental development of gilts during mid-late gestation. Based on the principle of backfat thickness consistency, 124 gilts at 65 d of gestation were assigned to three dietary groups: CON (basic diet, n = 41), LGABA (basic diet supplemented with 0.03% GABA, n = 42), and HGABA (basic diet supplemented with 0.06% GABA, n = 41). The litter performance, glucose tolerance, placental angiogenesis, and nutrients transporters were assessed. The LGABA group improved piglet vitality and placental efficiency and decreased area under the curve of glucose tolerance test compared to the CON group (P < 0.05). Meanwhile, the LGABA group enhanced placental vessel density, platelet endothelial cell adhesion molecule-1 levels and gene expression of fibroblast growth factor 18 (P < 0.05). Furthermore, LGABA showed an uptrend in glucose transporter type 1 mRNA level (P = 0.09). Taken together, this study revealed that the dietary supplementation of 0.03% GABA can improve piglet vitality, glucose intolerance, and placental development of gilts.
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Affiliation(s)
- Shuo Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Jinfeng Li
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Hongxuan Ye
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Shuangbo Huang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Zihao Huang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Deyuan Wu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Kaidi Ma
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Junyan Xie
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Institute of Subtropical Agriculture, Chinese Academy of Science, Research Center for Healthy Breeding of Livestock and Poultry, Changsha, Hunan 410125, China
| | - Yulong Yin
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Institute of Subtropical Agriculture, Chinese Academy of Science, Research Center for Healthy Breeding of Livestock and Poultry, Changsha, Hunan 410125, China
| | - Chengquan Tan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
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Wang S, Dong X, Maazi M, Chen N, Mahil A, Kopp JL. GABA treatment does not induce neogenesis of new endocrine cells from pancreatic ductal cells. Islets 2023; 15:2219477. [PMID: 37258189 DOI: 10.1080/19382014.2023.2219477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/25/2023] [Accepted: 05/25/2023] [Indexed: 06/02/2023] Open
Abstract
Previous studies indicated that ductal cells can contribute to endocrine neogenesis in adult rodents after alpha cells convert into beta cells. This can occur through Pax4 mis-expression in alpha cells or through long-term administration of gamma-aminobutyric acid (GABA) to healthy mice. GABA has also been reported to increase the number of beta cells through direct effects on their proliferation, but only in specific genetic mouse backgrounds. To test whether GABA induces neogenesis of beta cells from ductal cells or affects pancreatic cell proliferation, we administered GABA or saline over 2 or 6 months to Sox9CreER;R26RYFP mice in which 60-80% of large or small ducts were efficiently lineage labeled. We did not observe any increases in islet neogenesis from ductal cells between 1 and 2 months of age in saline treated mice, nor between 2 and 6 months of saline treatment, supporting previous studies indicating that adult ductal cells do not give rise to new endocrine cells during homeostasis. Unlike previous reports, we did not observe an increase in beta cell neogenesis after 2 or 6 months of GABA administration. Nor did we observe a significant increase in the pancreatic islet area, the number of insulin and glucagon double positive cells, or cell proliferation in the pancreas. This indicates that the effect of long term GABA administration on the pancreas is minimal or highly context dependent.
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Affiliation(s)
- Shihao Wang
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Xin Dong
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Mahan Maazi
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Nan Chen
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Amar Mahil
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Janel L Kopp
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
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Function of the GABAergic System in Diabetic Encephalopathy. Cell Mol Neurobiol 2023; 43:605-619. [PMID: 35460435 DOI: 10.1007/s10571-022-01214-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 03/17/2022] [Indexed: 11/03/2022]
Abstract
Diabetes is a common metabolic disease characterized by loss of blood sugar control and a high rate of complications. γ-Aminobutyric acid (GABA) functions as the primary inhibitory neurotransmitter in the adult mammalian brain. The normal function of the GABAergic system is affected in diabetes. Herein, we summarize the role of the GABAergic system in diabetic cognitive dysfunction, diabetic blood sugar control disorders, diabetes-induced peripheral neuropathy, diabetic central nervous system damage, maintaining diabetic brain energy homeostasis, helping central control of blood sugar and attenuating neuronal oxidative stress damage. We show the key regulatory role of the GABAergic system in multiple comorbidities in patients with diabetes and hope that further studies elucidating the role of the GABAergic system will yield benefits for the treatment and prevention of comorbidities in patients with diabetes.
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Harithpriya K, Jayasuriya R, Adhikari T, Rai A, Ramkumar KM. Modulation of transcription factors by small molecules in β-cell development and differentiation. Eur J Pharmacol 2023; 946:175606. [PMID: 36809813 DOI: 10.1016/j.ejphar.2023.175606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/21/2023]
Abstract
Transcription factors regulate gene expression and play crucial roles in development and differentiation of pancreatic β-cell. The expression and/or activities of these transcription factors are reduced when β-cells are chronically exposed to hyperglycemia, which results in loss of β-cell function. Optimal expression of such transcription factors is required to maintain normal pancreatic development and β-cell function. Over many other methods of regenerating β-cells, using small molecules to activate transcription factors has gained insights, resulting in β-cells regeneration and survival. In this review, we discuss the broad spectrum of transcription factors regulating pancreatic β-cell development, differentiation and regulation of these factors in normal and pathological states. Also, we have presented set of potential pharmacological effects of natural and synthetic compounds on activities of transcription factor involved in pancreatic β-cell regeneration and survival. Exploring these compounds and their action on transcription factors responsible for pancreatic β-cell function and survival could be useful in providing new insights for development of small molecule modulators.
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Affiliation(s)
- Kannan Harithpriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Ravichandran Jayasuriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Trishla Adhikari
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Awantika Rai
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Kunka Mohanram Ramkumar
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India.
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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: 4] [Impact Index Per Article: 4.0] [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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Wang Z, Fan L, Ni Y, Wu D, Ma A, Zhao Y, Li J, Cui Q, Zhou Y, Zhang L, Lou YR, Prud'homme GJ, Wang Q. Combined therapy of GABA and sitagliptin prevents high-fat diet impairment of beta-cell function. Mol Cell Endocrinol 2023; 559:111755. [PMID: 36049597 DOI: 10.1016/j.mce.2022.111755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 08/08/2022] [Accepted: 08/15/2022] [Indexed: 02/03/2023]
Abstract
We recently demonstrated that combined therapy of GABA and sitagliptin promoted beta-cell proliferation, and decreased beta-cell apoptosis in a multiple low-dose streptozotocin (STZ)-induced beta-cell injury mouse model. In this study, we examined whether this combined therapy is effective in ameliorating the impairment of beta-cell function caused by high-fat diet (HFD) feeding in mice. Male C57BL/6J mice were fed normal chow diet, HFD, or HFD combined with GABA, sitagliptin, or both drugs. Oral drug daily administration was initiated one week before HFD and maintained for two weeks. After two weeks of intervention, we found that GABA or sitagliptin administration ameliorated the impairment of glucose tolerance induced by HFD. This was associated with improved insulin secretion in vivo. Notably, combined administration of GABA and sitagliptin significantly enhanced these effects as compared to each of the monotherapies. Combined GABA and sitagliptin was superior at increasing beta-cell mass, and associated Ki67+ and PDX-1+ beta-cell counts. In addition, we found that HFD-induced compensatory beta-cell proliferation was associated with increased activation of unfolded protein response (UPR), as indicated by BiP expression. This could be an important mechanism of compensatory beta-cell proliferation, and beta cells treated with GABA and sitagliptin showed greater UPR activation. Our results suggest that the combined use of these agents produces superior therapeutic outcomes.
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Affiliation(s)
- Zhihong Wang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Linling Fan
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Yunzhi Ni
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Di Wu
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Anran Ma
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Ying Zhao
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Jia Li
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Qiaoli Cui
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Yue Zhou
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Li Zhang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Yan-Ru Lou
- Department of Clinical Pharmacy and Drug Administration, School of Pharmacy, Fudan University, Shanghai, China
| | - Gerald J Prud'homme
- Keenan Research Center for Biomedical Science, Division of Endocrinology and Metabolism, Unity Health Toronto (St. Michael's site), Toronto, Ontario, Canada; Department of Laboratory Medicine, Unity Health Toronto. Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada
| | - Qinghua Wang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China.
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Gu L, Cui X, Lin X, Yang J, Wei R, Hong T, Yang K. γ-aminobutyric acid modulates α-cell hyperplasia but not β-cell regeneration induced by glucagon receptor antagonism in type 1 diabetic mice. Acta Diabetol 2023; 60:19-28. [PMID: 36129525 DOI: 10.1007/s00592-022-01970-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/01/2022] [Indexed: 01/07/2023]
Abstract
AIMS To investigate whether treatment with γ-aminobutyric acid (GABA) alone or in combination with glucagon receptor (GCGR) monoclonal antibody (mAb) exerted beneficial effects on β-cell mass and α-cell mass, and to explore the origins of the regenerated β-cells in mice with type 1 diabetes (T1D). METHODS Streptozotocin (STZ)-induced T1D mice were treated with intraperitoneal injection of GABA (250 μg/kg per day) and/or REMD 2.59 (a GCGR mAb, 5 mg/kg per week), or IgG dissolved in PBS for 8 weeks. Plasma hormone levels and islet cell morphology were evaluated by ELISA and immunofluorescence, respectively. The origins of the regenerated β-cells were analyzed by double-immunostaining, α-cell lineage-tracing and BrdU-tracing studies. RESULTS After the 8-week treatment, GABA or GCGR mAb alone or in combination ameliorated hyperglycemia in STZ-induced T1D mice. GCGR mAb upregulated plasma insulin level and increased β-cell mass, and GABA appeared to have similar effects in T1D mice. However, combination treatment did not reveal any additive or synergistic effect. Interestingly, the GCGR mAb-induced increment of plasma glucagon level and α-cell mass was attenuated by the combined treatment of GABA. In addition, duct-derived β-cell neogenesis and α-to-β cell conversion but not β-cell proliferation contributed to the increased β-cell mass in T1D mice. CONCLUSION These results suggested that GABA attenuated α-cell hyperplasia but did not potentiates β-cell regeneration induced by GCGR mAb in T1D mice. Our findings provide novel insights into a combination treatment strategy for β-cell regeneration in T1D.
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Affiliation(s)
- Liangbiao Gu
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, 100191, China
- Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Xiaona Cui
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, 100191, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, 100191, China
| | - Xiafang Lin
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, 100191, China
| | - Jin Yang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, 100191, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, 100191, China
| | - Rui Wei
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, 100191, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, 100191, China
| | - Tianpei Hong
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, 100191, China.
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, 100191, China.
| | - Kun Yang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, 100191, China.
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Loss of Slc12a2 specifically in pancreatic β-cells drives metabolic syndrome in mice. PLoS One 2022; 17:e0279560. [PMID: 36580474 PMCID: PMC9799326 DOI: 10.1371/journal.pone.0279560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 12/11/2022] [Indexed: 12/30/2022] Open
Abstract
The risk of type-2 diabetes and cardiovascular disease is higher in subjects with metabolic syndrome, a cluster of clinical conditions characterized by obesity, impaired glucose metabolism, hyperinsulinemia, hyperlipidemia and hypertension. Diuretics are frequently used to treat hypertension in these patients, however, their use has long been associated with poor metabolic outcomes which cannot be fully explained by their diuretic effects. Here, we show that mice lacking the diuretic-sensitive Na+K+2Cl-cotransporter-1 Nkcc1 (Slc12a2) in insulin-secreting β-cells of the pancreatic islet (Nkcc1βKO) have reduced in vitro insulin responses to glucose. This is associated with islet hypoplasia at the expense of fewer and smaller β-cells. Remarkably, Nkcc1βKO mice excessively gain weight and progressive metabolic syndrome when fed a standard chow diet ad libitum. This is characterized by impaired hepatic insulin receptor activation and altered lipid metabolism. Indeed, overweight Nkcc1βKO but not lean mice had fasting and fed hyperglycemia, hypertriglyceridemia and non-alcoholic steatohepatitis. Notably, fasting hyperinsulinemia was detected earlier than hyperglycemia, insulin resistance, glucose intolerance and increased hepatic de novo gluconeogenesis. Therefore, our data provide evidence supporting the novel hypothesis that primary β-cell defects related to Nkcc1-regulated intracellular Cl-homeostasis and β-cell growth can result in the development of metabolic syndrome shedding light into additional potential mechanisms whereby chronic diuretic use may have adverse effects on metabolic homeostasis in susceptible individuals.
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Zhang H, Wang Y, Gao F, Liu R, Chen W, Zhao X, Sun Q, Sun X, Li J, Liu C, Ma X. GABA increases susceptibility to DSS-induced colitis in mice. J Funct Foods 2022. [DOI: 10.1016/j.jff.2022.105339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Prud’homme GJ, Kurt M, Wang Q. Pathobiology of the Klotho Antiaging Protein and Therapeutic Considerations. FRONTIERS IN AGING 2022; 3:931331. [PMID: 35903083 PMCID: PMC9314780 DOI: 10.3389/fragi.2022.931331] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/06/2022] [Indexed: 12/06/2022]
Abstract
The α-Klotho protein (henceforth denoted Klotho) has antiaging properties, as first observed in mice homozygous for a hypomorphic Klotho gene (kl/kl). These mice have a shortened lifespan, stunted growth, renal disease, hyperphosphatemia, hypercalcemia, vascular calcification, cardiac hypertrophy, hypertension, pulmonary disease, cognitive impairment, multi-organ atrophy and fibrosis. Overexpression of Klotho has opposite effects, extending lifespan. In humans, Klotho levels decline with age, chronic kidney disease, diabetes, Alzheimer’s disease and other conditions. Low Klotho levels correlate with an increase in the death rate from all causes. Klotho acts either as an obligate coreceptor for fibroblast growth factor 23 (FGF23), or as a soluble pleiotropic endocrine hormone (s-Klotho). It is mainly produced in the kidneys, but also in the brain, pancreas and other tissues. On renal tubular-cell membranes, it associates with FGF receptors to bind FGF23. Produced in bones, FGF23 regulates renal excretion of phosphate (phosphaturic effect) and vitamin D metabolism. Lack of Klotho or FGF23 results in hyperphosphatemia and hypervitaminosis D. With age, human renal function often deteriorates, lowering Klotho levels. This appears to promote age-related pathology. Remarkably, Klotho inhibits four pathways that have been linked to aging in various ways: Transforming growth factor β (TGF-β), insulin-like growth factor 1 (IGF-1), Wnt and NF-κB. These can induce cellular senescence, apoptosis, inflammation, immune dysfunction, fibrosis and neoplasia. Furthermore, Klotho increases cell-protective antioxidant enzymes through Nrf2 and FoxO. In accord, preclinical Klotho therapy ameliorated renal, cardiovascular, diabetes-related and neurodegenerative diseases, as well as cancer. s-Klotho protein injection was effective, but requires further investigation. Several drugs enhance circulating Klotho levels, and some cross the blood-brain barrier to potentially act in the brain. In clinical trials, increased Klotho was noted with renin-angiotensin system inhibitors (losartan, valsartan), a statin (fluvastatin), mTOR inhibitors (rapamycin, everolimus), vitamin D and pentoxifylline. In preclinical work, antidiabetic drugs (metformin, GLP-1-based, GABA, PPAR-γ agonists) also enhanced Klotho. Several traditional medicines and/or nutraceuticals increased Klotho in rodents, including astaxanthin, curcumin, ginseng, ligustilide and resveratrol. Notably, exercise and sport activity increased Klotho. This review addresses molecular, physiological and therapeutic aspects of Klotho.
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Affiliation(s)
- Gérald J. Prud’homme
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine, Keenan Research Centre for Biomedical Science, Unity Health Toronto, Toronto, ON, Canada
- *Correspondence: Gérald J. Prud’homme,
| | - Mervé Kurt
- Department of Laboratory Medicine, Keenan Research Centre for Biomedical Science, Unity Health Toronto, Toronto, ON, Canada
| | - Qinghua Wang
- Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical School, Fudan University, Shanghai, China
- Shanghai Yinuo Pharmaceutical Co., Ltd., Shanghai, China
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Yin J, Meng H, Lin J, Ji W, Xu T, Liu H. Pancreatic islet organoids-on-a-chip: how far have we gone? J Nanobiotechnology 2022; 20:308. [PMID: 35764957 PMCID: PMC9238112 DOI: 10.1186/s12951-022-01518-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/20/2022] [Indexed: 01/10/2023] Open
Abstract
Diabetes mellitus (DM) is a disease caused by dysfunction or disruption of pancreatic islets. The advent and development of microfluidic organoids-on-a-chip platforms have facilitated reproduce of complex and dynamic environment for tissue or organ development and complex disease processes. For the research and treatment of DM, the platforms have been widely used to investigate the physiology and pathophysiology of islets. In this review, we first highlight how pancreatic islet organoids-on-a-chip have improved the reproducibility of stem cell differentiation and organoid culture. We further discuss the efficiency of microfluidics in the functional evaluation of pancreatic islet organoids, such as single-islet-sensitivity detection, long-term real-time monitoring, and automatic glucose adjustment to provide relevant stimulation. Then, we present the applications of islet-on-a-chip technology in disease modeling, drug screening and cell replacement therapy. Finally, we summarize the development and challenges of islet-on-a-chip and discuss the prospects of future research.
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Affiliation(s)
- Jiaxiang Yin
- Bioland Laboratory, Guangzhou, Guangdong, China.,Guangzhou Laboratory, Guangzhou, Guangdong, China.,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Hao Meng
- Guangzhou Laboratory, Guangzhou, Guangdong, China
| | | | - Wei Ji
- Bioland Laboratory, Guangzhou, Guangdong, China.,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Tao Xu
- Guangzhou Laboratory, Guangzhou, Guangdong, China. .,School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China.
| | - Huisheng Liu
- Bioland Laboratory, Guangzhou, Guangdong, China. .,Guangzhou Laboratory, Guangzhou, Guangdong, China. .,School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China.
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16
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GABA and Fermented Curcuma longa L. Extract Enriched with GABA Ameliorate Obesity through Nox4-IRE1α Sulfonation-RIDD-SIRT1 Decay Axis in High-Fat Diet-Induced Obese Mice. Nutrients 2022; 14:nu14081680. [PMID: 35458241 PMCID: PMC9031358 DOI: 10.3390/nu14081680] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/12/2022] [Accepted: 04/15/2022] [Indexed: 12/11/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) is a natural amino acid with antioxidant activity and is often considered to have therapeutic potential against obesity. Obesity has long been linked to ROS and ER stress, but the effect of GABA on the ROS-associated ER stress axis has not been thoroughly explored. Thus, in this study, the effect of GABA and fermented Curcuma longa L. extract enriched with GABA (FCLL-GABA) on the ROS-related ER stress axis and inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) sulfonation were examined with the HFD model to determine the underlying anti-obesity mechanism. Here, GABA and FCLL-GABA supplementations significantly inhibited the weight gain in HFD fed mice. The GABA and FCLL-GABA supplementation lowered the expressions of adipogenic transcription factors such as PPAR-γ, C/EBPα, FAS, and SREBP-1c in white adipose tissue (WAT) and liver from HFD-fed mice. The enhanced hyper-nutrient dysmetabolism-based NADPH oxidase (Nox) 4 and the resultant IRE1α sulfonation-RIDD-SIRT1 decay under HFD conditions were controlled with GABA and FCLL-GABA. Notably, GABA and FCLL-GABA administration significantly increased AMPK and sirtuin 1 (SIRT1) levels in WAT of HFD-fed mice. These significant observations indicate that ER-localized Nox4-induced IRE1α sulfonation results in the decay of SIRT1 as a novel mechanism behind the positive implications of GABA on obesity. Moreover, the investigation lays a firm foundation for the development of FCLL-GABA as a functional ingredient.
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Zhang Z, Piro AL, Dai FF, Wheeler MB. Adaptive Changes in Glucose Homeostasis and Islet Function During Pregnancy: A Targeted Metabolomics Study in Mice. Front Endocrinol (Lausanne) 2022; 13:852149. [PMID: 35600586 PMCID: PMC9116578 DOI: 10.3389/fendo.2022.852149] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE Pregnancy is a dynamic state involving multiple metabolic adaptions in various tissues including the endocrine pancreas. However, a detailed characterization of the maternal islet metabolome in relation to islet function and the ambient circulating metabolome during pregnancy has not been established. METHODS A timed-pregnancy mouse model was studied, and age-matched non-pregnant mice were used as controls. Targeted metabolomics was applied to fasting plasma and purified islets during each trimester of pregnancy. Glucose homeostasis and islet function was assessed. Bioinformatic analyses were performed to reveal the metabolic adaptive changes in plasma and islets, and to identify key metabolic pathways associated with pregnancy. RESULTS Fasting glucose and insulin were found to be significantly lower in pregnant mice compared to non-pregnant controls, throughout the gestational period. Additionally, pregnant mice had superior glucose excursions and greater insulin response to an oral glucose tolerance test. Interestingly, both alpha and beta cell proliferation were significantly enhanced in early to mid-pregnancy, leading to significantly increased islet size seen in mid to late gestation. When comparing the plasma metabolome of pregnant and non-pregnant mice, phospholipid and fatty acid metabolism pathways were found to be upregulated throughout pregnancy, whereas amino acid metabolism initially decreased in early through mid pregnancy, but then increased in late pregnancy. Conversely, in islets, amino acid metabolism was consistently enriched throughout pregnancy, with glycerophospholid and fatty acid metabolism was only upregulated in late pregnancy. Specific amino acids (glutamate, valine) and lipids (acyl-alkyl-PC, diacyl-PC, and sphingomyelin) were found to be significantly differentially expressed in islets of the pregnant mice compared to controls, which was possibly linked to enhanced insulin secretion and islet proliferation. CONCLUSION Beta cell proliferation and function are elevated during pregnancy, and this is coupled to the enrichment of islet metabolites and metabolic pathways primarily associated with amino acid and glycerophospholipid metabolism. This study provides insight into metabolic adaptive changes in glucose homeostasis and islet function seen during pregnancy, which will provide a molecular rationale to further explore the regulation of maternal metabolism to avoid the onset of pregnancy disorders, including gestational diabetes.
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Affiliation(s)
- Ziyi Zhang
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China
| | - Anthony L. Piro
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Feihan F. Dai
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- *Correspondence: Feihan F. Dai, ; Michael B. Wheeler,
| | - Michael B. Wheeler
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Metabolism Research Group, Division of Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada
- *Correspondence: Feihan F. Dai, ; Michael B. Wheeler,
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Rezazadeh H, Sharifi MR, Soltani N. Insulin resistance and the role of gamma-aminobutyric acid. JOURNAL OF RESEARCH IN MEDICAL SCIENCES 2021; 26:39. [PMID: 34484371 PMCID: PMC8384006 DOI: 10.4103/jrms.jrms_374_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 12/09/2020] [Accepted: 02/02/2021] [Indexed: 12/17/2022]
Abstract
Insulin resistance (IR) is mentioned to be a disorder in insulin ability in insulin-target tissues. Skeletal muscle (SkM) and liver function are more affected by IR than other insulin target cells. SkM is the main site for the consumption of ingested glucose. An effective treatment for IR has two properties: An inhibition of β-cell death and a promotion of β-cell replication. Gamma-aminobutyric acid (GABA) can improve beta-cell mass and function. Multiple studies have shown that GABA decreases IR probably via increase in glucose transporter 4 (GLUT4) gene expression and prevention of gluconeogenesis pathway in the liver. This review focused on the general aspects of IR in skeletal muscle (SkM), liver; the cellular mechanism(s) lead to the development of IR in these organs, and the role of GABA to reduce insulin resistance.
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Affiliation(s)
- Hossein Rezazadeh
- Department of Physiology, School of Medicine, Isfahan University of Medical Science, Isfahan Iran
| | - Mohammad Reza Sharifi
- Department of Physiology, School of Medicine, Isfahan University of Medical Science, Isfahan Iran
| | - Nepton Soltani
- Department of Physiology, School of Medicine, Isfahan University of Medical Science, Isfahan Iran
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19
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Rice Compounds with Impact on Diabetes Control. Foods 2021; 10:foods10091992. [PMID: 34574099 PMCID: PMC8467539 DOI: 10.3390/foods10091992] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 01/20/2023] Open
Abstract
Rice is one of the most cultivated and consumed cereals worldwide. It is composed of starch, which is an important source of diet energy, hypoallergenic proteins, and other bioactive compounds with known nutritional functionalities. Noteworthy is that the rice bran (outer layer of rice grains), a side-stream product of the rice milling process, has a higher content of bioactive compounds than white rice (polished rice grains). Bran functional ingredients such as γ-oryzanol, phytic acid, ferulic acid, γ-aminobutyric acid, tocopherols, and tocotrienols (vitamin E) have been linked to several health benefits. In this study, we reviewed the effects of rice glycemic index, macronutrients, and bioactive compounds on the pathological mechanisms associated with diabetes, identifying the rice compounds potentially exerting protective activities towards disease control. The effects of starch, proteins, and bran bioactive compounds for diabetic control were reviewed and provide important insights about the nutritional quality of rice-based foods.
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20
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Bastin G, Luu L, Batchuluun B, Mighiu A, Beadman S, Zhang H, He C, Al Rijjal D, Wheeler MB, Heximer SP. RGS4-Deficiency Alters Intracellular Calcium and PKA-Mediated Control of Insulin Secretion in Glucose-Stimulated Beta Islets. Biomedicines 2021; 9:biomedicines9081008. [PMID: 34440212 PMCID: PMC8391461 DOI: 10.3390/biomedicines9081008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022] Open
Abstract
A number of diverse G-protein signaling pathways have been shown to regulate insulin secretion from pancreatic β-cells. Accordingly, regulator of G-protein signaling (RGS) proteins have also been implicated in coordinating this process. One such protein, RGS4, is reported to show both positive and negative effects on insulin secretion from β-cells depending on the physiologic context under which it was studied. We here use an RGS4-deficient mouse model to characterize previously unknown G-protein signaling pathways that are regulated by RGS4 during glucose-stimulated insulin secretion from the pancreatic islets. Our data show that loss of RGS4 results in a marked deficiency in glucose-stimulated insulin secretion during both phase I and phase II of insulin release in intact mice and isolated islets. These deficiencies are associated with lower cAMP/PKA activity and a loss of normal calcium surge (phase I) and oscillatory (phase II) kinetics behavior in the RGS4-deficient β-cells, suggesting RGS4 may be important for regulation of both Gαi and Gαq signaling control during glucose-stimulated insulin secretion. Together, these studies add to the known list of G-protein coupled signaling events that are controlled by RGS4 during glucose-stimulated insulin secretion and highlight the importance of maintaining normal levels of RGS4 function in healthy pancreatic tissues.
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Affiliation(s)
- Guillaume Bastin
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
- Ted Rogers Centre for Heart Research, Translational Biology and Engineering Program, University of Toronto, Toronto, ON M5G 1M1, Canada
- Heart and Stroke/Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON M5S 3H2, Canada
- Correspondence: ; Tel.: +33-658-469-334
| | - Lemieux Luu
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Battsetseg Batchuluun
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Alexandra Mighiu
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Stephanie Beadman
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Hangjung Zhang
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Changhao He
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Dana Al Rijjal
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Michael B. Wheeler
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Scott P. Heximer
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
- Ted Rogers Centre for Heart Research, Translational Biology and Engineering Program, University of Toronto, Toronto, ON M5G 1M1, Canada
- Heart and Stroke/Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON M5S 3H2, Canada
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21
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Dietary GABA and its combination with vigabatrin mimic calorie restriction and induce antiobesity-like effects in lean mice. J Funct Foods 2021. [DOI: 10.1016/j.jff.2021.104367] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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22
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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: 6] [Impact Index Per Article: 2.0] [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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Ling KC, Hagan DW, Santini-González J, Phelps EA. Effects of sustained GABA releasing implants on pancreatic islets in mice. Drug Deliv Transl Res 2021; 11:2198-2208. [PMID: 33454926 DOI: 10.1007/s13346-020-00886-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2020] [Indexed: 11/27/2022]
Abstract
Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter that is strongly and selectively synthesized in and secreted from pancreatic beta cells. Exogenously delivered GABA has been proposed to induce beta cell regeneration in type 1 diabetes, but these results have been difficult to replicate and may depend on the specifics of the animal model and drug delivery method used. Here, we developed a GABA-releasing ethylene-vinyl acetate polymer implant for sustained GABA delivery to the intraperitoneal space as an alternative to injected or oral GABA. We explored the effect of the GABA-releasing polymer implants compared to implanted osmotic pumps loaded with GABA on islet size in non-diabetic, outbred mice. We also attempted to monitor in vivo GABA release using HPLC on blood samples, but these measurements were confounded by high variability within treatment groups and unexpectedly high serum GABA levels in mice receiving GABA-negative implants. The ethylene-vinyl acetate polymer implants became heavily fibrosed with abdominal adhesion tissue, while the osmotic pumps had no macroscopic fibrosis. Histological analysis showed no significant effect of the sustained GABA delivery polymer or osmotic pumps on islet size, alpha cell to beta cell ratio, or the number of Ki67-positive islet cells. The GABA treatment time course was limited to two weeks due to the drug-release window of the polymer, while others reported islet-trophic effects of GABA after 10 to 12 weeks of treatment. In summary, our study is consistent with the concept that exogenous GABA administration does not significantly alter islet cell mass in non-diabetic CD-1 mice in the short-term. However, more data are needed including higher GABA doses and more prolonged treatment regimens for a better comparison with contrasting reports.
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Affiliation(s)
- Kevin C Ling
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - D Walker Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Jorge Santini-González
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Edward A Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
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Untereiner A, Xu J, Bhattacharjee A, Cabrera O, Hu C, Dai FF, Wheeler MB. γ-aminobutyric acid stimulates β-cell proliferation through the mTORC1/p70S6K pathway, an effect amplified by Ly49, a novel γ-aminobutyric acid type A receptor positive allosteric modulator. Diabetes Obes Metab 2020; 22:2021-2031. [PMID: 32558194 DOI: 10.1111/dom.14118] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/11/2020] [Accepted: 06/14/2020] [Indexed: 12/15/2022]
Abstract
AIM To examine the mechanism of action of γ-aminobutyric acid (GABA) on β-cell proliferation and investigate if co-treatment with Ly49, a novel GABA type A receptor positive allosteric modulator (GABAA -R PAM), amplifies this effect. METHODS Human or mouse islets were co-treated for 4-5 days with GABA and selected receptor or cell signalling pathway modulators. Immunofluorescence was used to determine protein co-localization, cell number or proliferation, and islet size. Osmotic minipumps were surgically implanted in mice to assess Ly49 effects on pancreatic β-cells. RESULTS Amplification of GABAA -R signalling enhanced GABA-stimulated β-cell proliferation in cultured mouse islets. Co-treatment of GABA with an inhibitor specific for PI3K, mTORC1/2, or p70S6K, abolished GABA-stimulated β-cell proliferation in mouse and human islets. Nuclear p-AktSer473 and p-p70S6KThr421/Ser424 expression in pancreatic β-cells was increased in GABA-treated mice compared with vehicle-treated mice, an effect augmented with GABA and Ly49 co-treatment. Mice co-treated with GABA and Ly49 exhibited enhanced β-cell area and proliferation compared with GABA-treated mice. Furthermore, S961 injection (an insulin receptor antagonist) resulted in enhanced plasma insulin in GABA and Ly49 co-treated mice compared with GABA-treated mice. Importantly, GABA co-treated with Ly49 increased β-cell proliferation in human islets providing a potential application for human subjects. CONCLUSIONS We show that GABA stimulates β-cell proliferation via the PI3K/mTORC1/p70S6K pathway in both mouse and human islets. Furthermore, we show that Ly49 enhances the β-cell regenerative effects of GABA, showing potential in the intervention of diabetes.
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Affiliation(s)
- Ashley Untereiner
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jie Xu
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Alpana Bhattacharjee
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Over Cabrera
- Diabetes and Complications Research, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana, USA
| | - Cheng Hu
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
- Institute for Metabolic Disease, Fengxian Central Hospital Affiliated to Southern Medical University, Shanghai, China
| | - 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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25
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Marquina-Sanchez B, Fortelny N, Farlik M, Vieira A, Collombat P, Bock C, Kubicek S. Single-cell RNA-seq with spike-in cells enables accurate quantification of cell-specific drug effects in pancreatic islets. Genome Biol 2020; 21:106. [PMID: 32375897 PMCID: PMC7201533 DOI: 10.1186/s13059-020-02006-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 03/27/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Single-cell RNA-seq (scRNA-seq) is emerging as a powerful tool to dissect cell-specific effects of drug treatment in complex tissues. This application requires high levels of precision, robustness, and quantitative accuracy-beyond those achievable with existing methods for mainly qualitative single-cell analysis. Here, we establish the use of standardized reference cells as spike-in controls for accurate and robust dissection of single-cell drug responses. RESULTS We find that contamination by cell-free RNA can constitute up to 20% of reads in human primary tissue samples, and we show that the ensuing biases can be removed effectively using a novel bioinformatics algorithm. Applying our method to both human and mouse pancreatic islets treated ex vivo, we obtain an accurate and quantitative assessment of cell-specific drug effects on the transcriptome. We observe that FOXO inhibition induces dedifferentiation of both alpha and beta cells, while artemether treatment upregulates insulin and other beta cell marker genes in a subset of alpha cells. In beta cells, dedifferentiation and insulin repression upon artemether treatment occurs predominantly in mouse but not in human samples. CONCLUSIONS This new method for quantitative, error-correcting, scRNA-seq data normalization using spike-in reference cells helps clarify complex cell-specific effects of pharmacological perturbations with single-cell resolution and high quantitative accuracy.
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Affiliation(s)
- Brenda Marquina-Sanchez
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Nikolaus Fortelny
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Matthias Farlik
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
- Department of Dermatology, Medical University of Vienna, 1090, Vienna, Austria
| | | | | | - Christoph Bock
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria.
- Department of Laboratory Medicine, Medical University of Vienna, 1090, Vienna, Austria.
| | - Stefan Kubicek
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria.
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26
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Hartig SM, Cox AR. Paracrine signaling in islet function and survival. J Mol Med (Berl) 2020; 98:451-467. [PMID: 32067063 DOI: 10.1007/s00109-020-01887-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 02/06/2023]
Abstract
The pancreatic islet is a dense cellular network comprised of several cell types with endocrine function vital in the control of glucose homeostasis, metabolism, and feeding behavior. Within the islet, endocrine hormones also form an intricate paracrine network with supportive cells (endothelial, neuronal, immune) and secondary signaling molecules regulating cellular function and survival. Modulation of these signals has potential consequences for diabetes development, progression, and therapeutic intervention. Beta cell loss, reduced endogenous insulin secretion, and dysregulated glucagon secretion are hallmark features of both type 1 and 2 diabetes that not only impact systemic regulation of glucose, but also contribute to the function and survival of cells within the islet. Advancing research and technology have revealed new islet biology (cellular identity and transcriptomes) and identified previously unrecognized paracrine signals and mechanisms (somatostatin and ghrelin paracrine actions), while shifting prior views of intraislet communication. This review will summarize the paracrine signals regulating islet endocrine function and survival, the disruption and dysfunction that occur in diabetes, and potential therapeutic targets to preserve beta cell mass and function.
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Affiliation(s)
- Sean M Hartig
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Aaron R Cox
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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27
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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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28
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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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29
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Gilon P. The Role of α-Cells in Islet Function and Glucose Homeostasis in Health and Type 2 Diabetes. J Mol Biol 2020; 432:1367-1394. [PMID: 31954131 DOI: 10.1016/j.jmb.2020.01.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/23/2019] [Accepted: 01/06/2020] [Indexed: 01/09/2023]
Abstract
Pancreatic α-cells are the major source of glucagon, a hormone that counteracts the hypoglycemic action of insulin and strongly contributes to the correction of acute hypoglycemia. The mechanisms by which glucose controls glucagon secretion are hotly debated, and it is still unclear to what extent this control results from a direct action of glucose on α-cells or is indirectly mediated by β- and/or δ-cells. Besides its hyperglycemic action, glucagon has many other effects, in particular on lipid and amino acid metabolism. Counterintuitively, glucagon seems also required for an optimal insulin secretion in response to glucose by acting on its cognate receptor and, even more importantly, on GLP-1 receptors. Patients with diabetes mellitus display two main alterations of glucagon secretion: a relative hyperglucagonemia that aggravates hyperglycemia, and an impaired glucagon response to hypoglycemia. Under metabolic stress states, such as diabetes, pancreatic α-cells also secrete GLP-1, a glucose-lowering hormone, whereas the gut can produce glucagon. The contribution of extrapancreatic glucagon to the abnormal glucose homeostasis is unclear. Here, I review the possible mechanisms of control of glucagon secretion and the role of α-cells on islet function in healthy state. I discuss the possible causes of the abnormal glucagonemia in diabetes, with particular emphasis on type 2 diabetes, and I briefly comment the current antidiabetic therapies affecting α-cells.
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Affiliation(s)
- Patrick Gilon
- Université Catholique de Louvain, Institute of Experimental and Clinical Research, Pole of Endocrinology, Diabetes and Nutrition, Avenue Hippocrate 55 (B1.55.06), Brussels, B-1200, Belgium.
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30
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Kusunoki M, Hayashi M, Shoji T, Uba T, Tanaka H, Sumi C, Matsuo Y, Hirota K. Propofol inhibits stromatoxin-1-sensitive voltage-dependent K + channels in pancreatic β-cells and enhances insulin secretion. PeerJ 2019; 7:e8157. [PMID: 31824770 PMCID: PMC6894434 DOI: 10.7717/peerj.8157] [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: 05/23/2019] [Accepted: 11/04/2019] [Indexed: 12/31/2022] Open
Abstract
Background Proper glycemic control is an important goal of critical care medicine, including perioperative patient care that can influence patients’ prognosis. Insulin secretion from pancreatic β-cells is generally assumed to play a critical role in glycemic control in response to an elevated blood glucose concentration. Many animal and human studies have demonstrated that perioperative drugs, including volatile anesthetics, have an impact on glucose-stimulated insulin secretion (GSIS). However, the effects of the intravenous anesthetic propofol on glucose metabolism and insulin sensitivity are largely unknown at present. Methods The effect of propofol on insulin secretion under low glucose or high glucose was examined in mouse MIN6 cells, rat INS-1 cells, and mouse pancreatic β-cells/islets. Cellular oxygen or energy metabolism was measured by Extracellular Flux Analyzer. Expression of glucose transporter 2 (GLUT2), potassium channels, and insulin mRNA was assessed by qRT-PCR. Protein expression of voltage-dependent potassium channels (Kv2) was also assessed by immunoblot. Propofol’s effects on potassium channels including stromatoxin-1-sensitive Kv channels and cellular oxygen and energy metabolisms were also examined. Results We showed that propofol, at clinically relevant doses, facilitates insulin secretion under low glucose conditions and GSIS in MIN6, INS-1 cells, and pancreatic β-cells/islets. Propofol did not affect intracellular ATP or ADP concentrations and cellular oxygen or energy metabolism. The mRNA expression of GLUT2 and channels including the voltage-dependent calcium channels Cav1.2, Kir6.2, and SUR1 subunit of KATP, and Kv2 were not affected by glucose or propofol. Finally, we demonstrated that propofol specifically blocks Kv currents in β-cells, resulting in insulin secretion in the presence of glucose. Conclusions Our data support the hypothesis that glucose induces membrane depolarization at the distal site, leading to KATP channel closure, and that the closure of Kv channels by propofol depolarization in β-cells enhances Ca2+ entry, leading to insulin secretion. Because its activity is dependent on GSIS, propofol and its derivatives are potential compounds that enhance and initiate β-cell electrical activity.
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Affiliation(s)
- Munenori Kusunoki
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan.,Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Mikio Hayashi
- Department of Cell Physiology, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Tomohiro Shoji
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan.,Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Takeo Uba
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan.,Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Hiromasa Tanaka
- Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Chisato Sumi
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan.,Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Yoshiyuki Matsuo
- Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Kiichi Hirota
- Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
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31
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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] [Received: 05/23/2018] [Accepted: 10/04/2019] [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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32
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Orser BA. Musings from an Unlikely Clinician-Scientist: 2018 American Society of Anesthesiologists Excellence in Research Award. Anesthesiology 2019; 131:795-800. [PMID: 31335546 DOI: 10.1097/aln.0000000000002881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This article, which stems from the 2018 American Society of Anesthesiologists Excellence in Research Award Lecture, aims to encourage young investigators, offer advice, and share several early life experiences that have influenced the author's career as an anesthesiologist and clinician-scientist. The article also describes key discoveries that have increased understanding of the role of γ-aminobutyric acid type A (GABAA) receptors in health and disease. The author's research team identified the unique pharmacologic properties of extrasynaptic GABAA receptors and their role in the anesthetic state. The author's team also showed that extrasynaptic GABAA receptors expressed in neuronal and nonneuronal cells contribute to a variety of disorders and are novel drug targets. The author's overarching message is that young investigators must create their own unique narratives, train hard, be relentless in their studies and-most important-enjoy the journey of discovering new truths that will ultimately benefit patients.
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Affiliation(s)
- Beverley A Orser
- From the Department of Anesthesia and the Department of Physiology, University of Toronto, Toronto, Canada; and the Department of Anesthesia, Sunnybrook Health Sciences Centre, Toronto, Canada
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33
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Glieberman AL, Pope BD, Zimmerman JF, Liu Q, Ferrier JP, Kenty JHR, Schrell AM, Mukhitov N, Shores KL, Tepole AB, Melton DA, Roper MG, Parker KK. Synchronized stimulation and continuous insulin sensing in a microfluidic human Islet on a Chip designed for scalable manufacturing. LAB ON A CHIP 2019; 19:2993-3010. [PMID: 31464325 PMCID: PMC6814249 DOI: 10.1039/c9lc00253g] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Pancreatic β cell function is compromised in diabetes and is typically assessed by measuring insulin secretion during glucose stimulation. Traditionally, measurement of glucose-stimulated insulin secretion involves manual liquid handling, heterogeneous stimulus delivery, and enzyme-linked immunosorbent assays that require large numbers of islets and processing time. Though microfluidic devices have been developed to address some of these limitations, traditional methods for islet testing remain the most common due to the learning curve for adopting microfluidic devices and the incompatibility of most device materials with large-scale manufacturing. We designed and built a thermoplastic, microfluidic-based Islet on a Chip compatible with commercial fabrication methods, that automates islet loading, stimulation, and insulin sensing. Inspired by the perfusion of native islets by designated arterioles and capillaries, the chip delivers synchronized glucose pulses to islets positioned in parallel channels. By flowing suspensions of human cadaveric islets onto the chip, we confirmed automatic capture of islets. Fluorescent glucose tracking demonstrated that stimulus delivery was synchronized within a two-minute window independent of the presence or size of captured islets. Insulin secretion was continuously sensed by an automated, on-chip immunoassay and quantified by fluorescence anisotropy. By integrating scalable manufacturing materials, on-line, continuous insulin measurement, and precise spatiotemporal stimulation into an easy-to-use design, the Islet on a Chip should accelerate efforts to study and develop effective treatments for diabetes.
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Affiliation(s)
- Aaron L Glieberman
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138, USA.
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34
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Abstract
BACKGROUND Current therapeutic strategies for type 1 (T1DM) and type 2 diabetes mellitus (T2DM) rely on increasing or substituting endogenous insulin secretion in combination with lifestyle changes. β-cell regeneration, a process whereby new β-cells arise from progenitors, self-renewal or transdifferentiation, has the potential to become a viable route to insulin self-sufficiency. Current regeneration strategies capture many of the transcriptomic and protein features of native β-cells, generating cells capable of glucose-dependent insulin secretion in vitro and alleviation of hyperglycemia in vivo. However, whether novel β-cells display appreciable heterogeneity remains poorly understood, with potential consequences for long-term functional robustness. SCOPE OF REVIEW The review brings together crucial discoveries in the β-cell regeneration field with state-of-the-art knowledge regarding β-cell heterogeneity. Aspects that might aid production of longer-lasting and more plastic regenerated β-cells are highlighted and discussed. MAJOR CONCLUSIONS Different β-cell regeneration approaches result in a similar outcome: glucose-sensitive, insulin-positive cells that mimic the native β-cell phenotype but which lack normal plasticity. The β-cell subpopulations identified to date expand our understanding of β-cell survival, proliferation and function, signposting the direction for future regeneration strategies. Therefore, regenerated β-cells should exhibit stimulus-dependent differences in gene and protein expression, as well as establish a functional network with different β-cells, all while coexisting with other cell types on a three-dimensional platform.
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Affiliation(s)
- Daniela Nasteska
- Institute of Metabolism and Systems Research (IMSR), Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Katrina Viloria
- Institute of Metabolism and Systems Research (IMSR), Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Lewis Everett
- Institute of Metabolism and Systems Research (IMSR), Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK.
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35
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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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36
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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: 32] [Impact Index Per Article: 6.4] [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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An Updated Review on Pharmaceutical Properties of Gamma-Aminobutyric Acid. Molecules 2019; 24:molecules24152678. [PMID: 31344785 PMCID: PMC6696076 DOI: 10.3390/molecules24152678] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/08/2019] [Accepted: 07/19/2019] [Indexed: 12/19/2022] Open
Abstract
Gamma-aminobutyric acid (Gaba) is a non-proteinogenic amino acid that is widely present in microorganisms, plants, and vertebrates. So far, Gaba is well known as a main inhibitory neurotransmitter in the central nervous system. Its physiological roles are related to the modulation of synaptic transmission, the promotion of neuronal development and relaxation, and the prevention of sleeplessness and depression. Besides, various pharmaceutical properties of Gaba on non-neuronal peripheral tissues and organs were also reported due to anti-hypertension, anti-diabetes, anti-cancer, antioxidant, anti-inflammation, anti-microbial, anti-allergy, hepato-protection, reno-protection, and intestinal protection. Therefore, Gaba may be considered as potential alternative therapeutics for prevention and treatment of various diseases. Accordingly, this updated review was mainly focused to describe the pharmaceutical properties of Gaba as well as emphasize its important role regarding human health.
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