1
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Cervetto C, Pistollato F, Amato S, Mendoza-de Gyves E, Bal-Price A, Maura G, Marcoli M. Assessment of neurotransmitter release in human iPSC-derived neuronal/glial cells: a missing in vitro assay for regulatory developmental neurotoxicity testing. Reprod Toxicol 2023; 117:108358. [PMID: 36863571 PMCID: PMC10112275 DOI: 10.1016/j.reprotox.2023.108358] [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: 11/18/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/04/2023]
Abstract
Human induced pluripotent stem cell (hiPSC)-derived neural stem cells (NSCs) and their differentiated neuronal/glial derivatives have been recently considered suitable to assess in vitro developmental neurotoxicity (DNT) triggered by exposure to environmental chemicals. The use of human-relevant test systems combined with in vitro assays specific for different neurodevelopmental events, enables a mechanistic understanding of the possible impact of environmental chemicals on the developing brain, avoiding extrapolation uncertainties associated with in vivo studies. Currently proposed in vitro battery for regulatory DNT testing accounts for several assays suitable to study key neurodevelopmental processes, including NSC proliferation and apoptosis, differentiation into neurons and glia, neuronal migration, synaptogenesis, and neuronal network formation. However, assays suitable to measure interference of compounds with neurotransmitter release or clearance are at present not included, which represents a clear gap of the biological applicability domain of such a testing battery. Here we applied a HPLC-based methodology to measure the release of neurotransmitters in a previously characterized hiPSC-derived NSC model undergoing differentiation towards neurons and glia. Glutamate release was assessed in control cultures and upon depolarization, as well as in cultures repeatedly exposed to some known neurotoxicants (BDE47 and lead) and chemical mixtures. Obtained data indicate that these cells have the ability to release glutamate in a vesicular manner, and that both glutamate clearance and vesicular release concur in the maintenance of extracellular glutamate levels. In conclusion, analysis of neurotransmitter release is a sensitive readout that should be included in the envisioned battery of in vitro assays for DNT testing.
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Affiliation(s)
- Chiara Cervetto
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy; Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research, Centro 3R, Pisa, Italy.
| | | | - Sarah Amato
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy
| | | | - Anna Bal-Price
- European Commission, Joint Research Centre, JRC, Ispra, Italy.
| | - Guido Maura
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy
| | - Manuela Marcoli
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy; Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research, Centro 3R, Pisa, Italy.
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2
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Hagan DW, Ferreira SM, Santos GJ, Phelps EA. The role of GABA in islet function. Front Endocrinol (Lausanne) 2022; 13:972115. [PMID: 36246925 PMCID: PMC9558271 DOI: 10.3389/fendo.2022.972115] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Gamma aminobutyric acid (GABA) is a non-proteinogenic amino acid and neurotransmitter that is produced in the islet at levels as high as in the brain. GABA is synthesized by the enzyme glutamic acid decarboxylase (GAD), of which the 65 kDa isoform (GAD65) is a major autoantigen in type 1 diabetes. Originally described to be released via synaptic-like microvesicles or from insulin secretory vesicles, beta cells are now understood to release substantial quantities of GABA directly from the cytosol via volume-regulated anion channels (VRAC). Once released, GABA influences the activity of multiple islet cell types through ionotropic GABAA receptors and metabotropic GABAB receptors. GABA also interfaces with cellular metabolism and ATP production via the GABA shunt pathway. Beta cells become depleted of GABA in type 1 diabetes (in remaining beta cells) and type 2 diabetes, suggesting that loss or reduction of islet GABA correlates with diabetes pathogenesis and may contribute to dysfunction of alpha, beta, and delta cells in diabetic individuals. While the function of GABA in the nervous system is well-understood, the description of the islet GABA system is clouded by differing reports describing multiple secretion pathways and effector functions. This review will discuss and attempt to unify the major experimental results from over 40 years of literature characterizing the role of GABA in the islet.
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Affiliation(s)
- D. Walker Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Sandra M. Ferreira
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Gustavo J. Santos
- Islet Biology and Metabolism Lab – I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis, Brazil
| | - Edward A. Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
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3
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Dolan R, Lampejo AO, Santini-González J, Hodges NA, Phelps EA, Murfee WL. A Novel ex vivo Method for Investigating Vascularization of Transplanted Islets. J Vasc Res 2022; 59:229-238. [PMID: 35462373 PMCID: PMC9308658 DOI: 10.1159/000523925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 03/01/2022] [Indexed: 11/19/2022] Open
Abstract
Revascularization of transplanted pancreatic islets is critical for survival and treatment of type 1 diabetes. Questions concerning how islets influence local microvascular networks and how networks form connections with islets remain understudied and motivate the need for new models that mimic the complexity of real tissue. Recently, our laboratory established the rat mesentery culture model as a tool to investigate cell dynamics involved in microvascular growth. An advantage is the ability to observe blood vessels, lymphatics, and immune cells. The objective of this study was to establish the rat mesentery tissue culture model as a useful tool to investigate islet tissue integration. DiI-labeled islets were seeded onto adult rat mesentery tissues and cultured for up to 3 days. Live lectin labeling enabled time-lapse observation of vessel growth. During culture, DiI-positive islets remained intact. Radial lectin-positive capillary sprouts with DiI labeling were observed to form from islets and connect to host networks. Lectin-positive vessels from host networks were also seen growing toward islets. PECAM and NG2 labeling confirmed that vessels sprouting from islets contained endothelial cells and pericytes. Our results introduce the rat mesentery culture model as a platform for investigating dynamics associated with the initial revascularization of transplanted islets.
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Affiliation(s)
- Robert Dolan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Arinola O Lampejo
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Jorge Santini-González
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Nicholas A Hodges
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Edward A Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Walter L Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
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4
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Kamat V, Radtke JR, Hu Q, Wang W, Sweet IR, Hampe CS. Autoantibodies directed against glutamate decarboxylase interfere with glucose-stimulated insulin secretion in dispersed rat islets. Int J Exp Pathol 2022; 103:140-148. [PMID: 35246889 PMCID: PMC9264341 DOI: 10.1111/iep.12437] [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: 08/18/2021] [Revised: 01/17/2022] [Accepted: 02/20/2022] [Indexed: 11/28/2022] Open
Abstract
Islet autoantibodies, including autoantibodies directed against the 65kDa isoform of glutamate decarboxylase (GAD65Ab), are present in the majority of patients with newly diagnosed type 1 diabetes (T1D). Whereas these autoantibodies are historically viewed as an epiphenomenon of the autoimmune response with no significant pathogenic function, we consider in this study the possibility that they impact the major islet function, namely glucose-stimulated insulin secretion. Two human monoclonal GAD65Ab (GAD65 mAb) (b78 and b96.11) were investigated for uptake by live rat beta cells, subcellular localization and their effect on glucose-stimulated insulin secretion. The GAD65 mAbs were internalized by live pancreatic beta cells, where they localized to subcellular structures in an epitope-specific manner. Importantly, GAD65 mAb b78 inhibited, while GAD65 mAb b96.11 enhanced, glucose-stimulated insulin secretion (GSIS). These opposite effects on GSIS rule out non-specific effects of the antibodies and suggest that internalization of the antibody leads to epitope-specific interaction with intracellular machinery regulating insulin granule release. The most likely explanation for the alteration of GSIS by GAD65 Abs is via changes in GABA release due to inhibition or change in GAD65 enzyme activity. This is the first report indicating an active role of GAD65Ab in the pathogenesis of T1D.
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Affiliation(s)
- Varun Kamat
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Jared R Radtke
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Qingxun Hu
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington, USA
| | - Wang Wang
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington, USA
| | - Ian R Sweet
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Christiane S Hampe
- Department of Medicine, University of Washington, Seattle, Washington, USA
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5
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Willis A, Pratt JA, Morris BJ. BDNF and JNK Signaling Modulate Cortical Interneuron and Perineuronal Net Development: Implications for Schizophrenia-Linked 16p11.2 Duplication Syndrome. Schizophr Bull 2020; 47:812-826. [PMID: 33067994 PMCID: PMC8084442 DOI: 10.1093/schbul/sbaa139] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Schizophrenia (SZ) is a neurodevelopmental disorder caused by the interaction of genetic and environmental risk factors. One of the strongest genetic risk variants is duplication (DUP) of chr.16p11.2. SZ is characterized by cortical gamma-amino-butyric acid (GABA)ergic interneuron dysfunction and disruption to surrounding extracellular matrix structures, perineuronal nets (PNNs). Developmental maturation of GABAergic interneurons, and also the resulting closure of the critical period of cortical plasticity, is regulated by brain-derived neurotrophic factor (BDNF), although the mechanisms involved are unknown. Here, we show that BDNF promotes GABAergic interneuron and PNN maturation through JNK signaling. In mice reproducing the 16p11.2 DUP, where the JNK upstream activator Taok2 is overexpressed, we find that JNK is overactive and there are developmental abnormalities in PNNs, which persist into adulthood. Prefrontal cortex parvalbumin (PVB) expression is reduced, while PNN intensity is increased. Additionally, we report a unique role for TAOK2 signaling in the regulation of PVB interneurons. Our work implicates TAOK2-JNK signaling in cortical interneuron and PNN development, and in the responses to BDNF. It also demonstrates that over-activation of this pathway in conditions associated with SZ risk causes long-lasting disruption in cortical interneurons.
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Affiliation(s)
- Ashleigh Willis
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, Scotland, UK
| | - Judith A Pratt
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, UK
| | - Brian J Morris
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, Scotland, UK,To whom correspondence should be addressed; Institute of Neuroscience and Psychology, University of Glasgow, G12 8QQ, Glasgow, Scotland, UK; tel: 0044-141-330-5361, fax: 0044-141-330-5659, e-mail:
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6
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Beik P, Ciesielska M, Kucza M, Kurczewska A, Kuźmińska J, Maćkowiak B, Niechciał E. Prevention of Type 1 Diabetes: Past Experiences and Future Opportunities. J Clin Med 2020; 9:E2805. [PMID: 32872668 PMCID: PMC7563637 DOI: 10.3390/jcm9092805] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/14/2020] [Accepted: 08/28/2020] [Indexed: 12/11/2022] Open
Abstract
Type 1 diabetes (T1D) results from autoimmune destruction of insulin-producing beta-cells in the pancreas, caused by the interplay of genetic and environmental factors. Despite the introduction of advanced technologies for diabetes management, most patients fail to achieve target glycemic control, and T1D still has a high burden of long-term end-organ complications. Over several decades, multiple clinical trials have attempted to find prevention for T1D in at-risk individuals or to stabilize, ultimately reverse, the disease in those with T1D. To date, T1D remains yet incurable condition; however, recently improved understanding of the natural history of the disease may lead to new strategies to preserve or improve beta-cell function in those at increased risk and T1D patients. This publication aims to provide an overview of past experiences and recent findings in the prevention of T1D.
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Affiliation(s)
| | | | | | | | | | | | - Elżbieta Niechciał
- Department of Pediatric Diabetes and Obesity, Poznan University of Medical Sciences, Szpitalna Street 27/33, 60-572 Poznan, Poland; (P.B.); (M.C.); (M.K.); (A.K.); (J.K.); (B.M.)
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7
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Seo JH, Lee YJ, Lee KH, Gireesh E, Skinner H, Westerveld M. Autoimmune encephalitis and epilepsy: evolving definition and clinical spectrum. Clin Exp Pediatr 2020; 63:291-300. [PMID: 31431603 PMCID: PMC7402981 DOI: 10.3345/kjp.2019.00598] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/13/2019] [Indexed: 12/11/2022] Open
Abstract
Advances in autoimmune encephalitis studies in the past 10 years have led to the identification of new syndromes and biomarkers that have transformed the diagnostic approach to the disorder. The disorder or syndrome has been linked to a wide variety of pathologic processes associated with the neuron-specific autoantibodies targeting intracellular and plasma membrane antigens. However, current criteria for autoimmune encephalitis are quite dependent on antibody testing and responses to immunotherapy, which might delay the diagnosis. This form of encephalitis can involve the multifaceted presentation of seizures and unexpected behavioral changes. The spectrum of neuropsychiatric symptoms in children is less definitive than that in adults, and the incorporation of clinical, immunological, electrophysiological, and neuroradiological results is critical to the diagnostic approach. In this review, we document the clinical and immunologic characteristics of autoimmune encephalitis known to date, with the goal of helping clinicians in differential diagnosis and to provide prompt and effective treatment.
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Affiliation(s)
- Joo Hee Seo
- Comprehensive Epilepsy Center, AdventHealth for Children, Orlando, FL, USA
| | - Yun-Jin Lee
- Comprehensive Epilepsy Center, AdventHealth for Children, Orlando, FL, USA.,Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University College of Medicine, Yangsan, Korea
| | - Ki Hyeong Lee
- Comprehensive Epilepsy Center, AdventHealth for Children, Orlando, FL, USA
| | - Elakkat Gireesh
- Comprehensive Epilepsy Center, AdventHealth for Children, Orlando, FL, USA
| | - Holly Skinner
- Comprehensive Epilepsy Center, AdventHealth for Children, Orlando, FL, USA
| | - Michael Westerveld
- Comprehensive Epilepsy Center, AdventHealth for Children, Orlando, FL, USA
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8
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Sieveritz B, Arbuthnott GW. Prelimbic cortical targets of ventromedial thalamic projections include inhibitory interneurons and corticostriatal pyramidal neurons in the rat. Brain Struct Funct 2020; 225:2057-2076. [PMID: 32661702 PMCID: PMC7473973 DOI: 10.1007/s00429-020-02109-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 06/28/2020] [Indexed: 12/24/2022]
Abstract
Ventromedial thalamic axons innervate cortical layer I and make contacts onto the apical dendritic tuft of pyramidal neurons. Optical stimulation of ventromedial thalamic axon terminals in prefrontal cortical areas in mouse brain slices evokes responses in corticocortical, corticothalamic and layer I inhibitory interneurons. Using anterograde tracing techniques and immunohistochemistry in male Sprague–Dawley rats, we provide anatomical evidence that ventromedial thalamic axon terminals in prelimbic cortex make contacts onto pyramidal neurons and, in particular, onto corticostriatal neurons as well as layer I inhibitory interneurons. Using stereology, we made quantitative estimates of contacts in uppermost prelimbic layer I onto dendrites of pyramidal neurons, corticostriatal neurons and layer I inhibitory interneurons. Prefrontal cortex has long been associated with decision making. Specifically, corticostriatal neurons in rat prelimbic cortex play an important role in cost–benefit decision making. Although recent experiments have detailed the physiology of this area in thalamocortical circuits, the extent of the impact of ventromedial thalamic input on corticostriatal neurons or layer I inhibitory interneurons has not been explored. Our quantitative anatomical results provide evidence that most ventromedial thalamic input to pyramidal neurons is provided to corticostriatal neurons and that overall more contacts are made onto the population of excitatory than onto the population of inhibitory neurons.
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Affiliation(s)
- Bianca Sieveritz
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan.
| | - Gordon W Arbuthnott
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
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9
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Oikari LE, Yu C, Okolicsanyi RK, Avgan N, Peall IW, Griffiths LR, Haupt LM. HSPGs glypican‐1 and glypican‐4 are human neuronal proteins characteristic of different neural phenotypes. J Neurosci Res 2020; 98:1619-1645. [DOI: 10.1002/jnr.24666] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/09/2020] [Accepted: 05/14/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Lotta E. Oikari
- Genomics Research Centre Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Kelvin Grove QLD Australia
| | - Chieh Yu
- Genomics Research Centre Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Kelvin Grove QLD Australia
| | - Rachel K. Okolicsanyi
- Genomics Research Centre Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Kelvin Grove QLD Australia
| | - Nesli Avgan
- Genomics Research Centre Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Kelvin Grove QLD Australia
| | - Ian W. Peall
- Genomics Research Centre Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Kelvin Grove QLD Australia
| | - Lyn R. Griffiths
- Genomics Research Centre Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Kelvin Grove QLD Australia
| | - Larisa M. Haupt
- Genomics Research Centre Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Kelvin Grove QLD Australia
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10
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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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11
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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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12
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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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13
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Cho JH, Lee KM, Lee YI, Nam HG, Jeon WB. Glutamate decarboxylase 67 contributes to compensatory insulin secretion in aged pancreatic islets. Islets 2019; 11:33-43. [PMID: 31084527 PMCID: PMC6548491 DOI: 10.1080/19382014.2019.1599708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Pancreatic islets play an essential role in regulating blood glucose levels. Age-dependent development of glucose intolerance and insulin resistance results in hyperglycemia, which in turn stimulates insulin synthesis and secretion from aged islets, to fulfill the increased demand for insulin. However, the mechanism underlying enhanced insulin secretion remains unknown. Glutamic acid decarboxylase 67 (GAD67) catalyzes the conversion of glutamate into γ-aminobutyric acid (GABA) and CO2. Both glutamate and GABA can affect islet function. Here, we investigated the role of GAD67 in insulin secretion in young (3 month old) and aged (24 month old) C57BL/6J male mice. Unlike young mice, aged mice displayed glucose-intolerance and insulin-resistance. However, aged mice secreted more insulin and showed lower fed blood glucose levels than young mice. GAD67 levels in primary islets increased with aging and in response to high glucose levels. Inhibition of GAD67 activity using a potent inhibitor of GAD, 3-mercaptopropionic acid, abrogated glucose-stimulated insulin secretion from a pancreatic β-cell line and from young and aged islets. Collectively, our results suggest that blood glucose levels regulate GAD67 expression, which contributes to β-cell responses to impaired glucose homeostasis caused by advanced aging.
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Affiliation(s)
- Jung Hoon Cho
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang, Korea
- Center for Plant Aging Research, Institute for Basic Science, Daegu, Korea
| | - Kyeong-Min Lee
- Laboratory of Biochemistry and Cellular Engineering, DGIST, Daegu, Korea
| | - Yun-Il Lee
- Well Aging Research Center, DGIST, Daegu, Korea
| | - Hong Gil Nam
- Center for Plant Aging Research, Institute for Basic Science, Daegu, Korea
- Department of New Biology, DGIST, Daegu, Korea
| | - Won Bae Jeon
- Laboratory of Biochemistry and Cellular Engineering, DGIST, Daegu, Korea
- Department of New Biology, DGIST, Daegu, Korea
- CONTACT Won Bae Jeon Laboratory of Biochemistry and Cellular Engineering, DGIST, Daegu 42988, Korea
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14
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Esposito S, Principi N, Calabresi P, Rigante D. An evolving redefinition of autoimmune encephalitis. Autoimmun Rev 2018; 18:155-163. [PMID: 30572142 DOI: 10.1016/j.autrev.2018.08.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 08/18/2018] [Indexed: 12/13/2022]
Abstract
Autoimmune encephalitis encompasses a wide variety of protean pathologic processes associated with the presence of antibodies against neuronal intracellular proteins, synaptic receptors, ion channels and/or neuronal surface proteins. This type of encephalitis can also involve children with complex patterns of seizures and unexpected behavioural changes, which jeopardize their prompt recognition and treatment. Many epidemiological studies have shown that numerous immune-based forms of encephalitis can be encountered, almost surpassing the rate of postinfectious encephalitides. However, the overall exact prevalence of autoimmune encephalopathies remains underestimated, and the definition of diagnostic algorithms results muddled. The spectrum of neuropsychiatric manifestations in the pediatric population with autoimmune encephalitis is less clear than in adults, but the integration of clinical, immunological, electrophysiological and neuroradiological data is essential for a general approach to patients. In this review we report the most relevant data about both immunologic and clinical characteristics of the main autoimmune encephalitides recognized so far, with the aim of assisting clinicians in the differential diagnosis and favouring an early effective treatment. Correlations between phenotype and autoantibodies involved in the neurological damage of autoimmune encephalitis are largely unknown in the first years of life, because of the relatively small number of pediatric patients adequately studied. Future multicenter collaborative studies are needed to improve the diagnostic approach and tailor personalized therapies in the long-term.
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Affiliation(s)
- Susanna Esposito
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Perugia, Italy.
| | | | - Paolo Calabresi
- Neurology Clinic, Department of Medicine, Università degli Studi di Perugia, Perugia, Italy
| | - Donato Rigante
- Institute of Pediatrics, Università Cattolica Sacro Cuore, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
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15
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Magri C, Giacopuzzi E, La Via L, Bonini D, Ravasio V, Elhussiny MEA, Orizio F, Gangemi F, Valsecchi P, Bresciani R, Barbon A, Vita A, Gennarelli M. A novel homozygous mutation in GAD1 gene described in a schizophrenic patient impairs activity and dimerization of GAD67 enzyme. Sci Rep 2018; 8:15470. [PMID: 30341396 PMCID: PMC6195539 DOI: 10.1038/s41598-018-33924-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 10/08/2018] [Indexed: 12/30/2022] Open
Abstract
Recently, by whole exome sequencing of schizophrenia (SCZ) patients, we identified a subject that was homozygous for a novel missense substitution (c.391 A > G) in the glutamate acid decarboxylase 1 (GAD1) gene. GAD1 encodes for GAD67 enzyme, catalyzing the production of gamma-aminobutyric acid (GABA) from L-glutamic acid. Here, we studied the impact of this mutation on GAD67 activity, dimerization and subcellular localization. Biochemical assay revealed that c.391 A > G reduces GAD67 enzymatic activity by ~30%, probably due to the impaired homodimerization of homozygous mutants as highlighted by proximity ligation assays. The mutational screening of 120 genes of the "GABAergic system" in a cohort of 4,225 SCZ cases and 5,834 controls (dbGaP: phs000473.v1.p2), did not identify other cases that were homozygous for ultra-rare variants in GAD1, but highlighted an increased frequency of cases that were homozygous for rare variants in genes of the GABA system (SCZ: 0.14% vs. Controls: 0.00%; p-value = 0.0055). In conclusion, this study demonstrates the functional impact of c.391 A > G variant and its biological effect makes it a good candidate as risk variant for SCZ. This study also supports an involvement of ultra-rare variants in GABAergic genes in the etiopathogenesis of SCZ.
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Affiliation(s)
- Chiara Magri
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
| | - Edoardo Giacopuzzi
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Luca La Via
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Daniela Bonini
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Viola Ravasio
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Mohammed E A Elhussiny
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Flavia Orizio
- Unit of Biotechnology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Fabrizio Gangemi
- Unit of Physics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Paolo Valsecchi
- Neuroscience Section, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Department of Mental Health, Spedali Civili Hospital, Brescia, Italy
| | - Roberto Bresciani
- Unit of Biotechnology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Alessandro Barbon
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Antonio Vita
- Neuroscience Section, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Department of Mental Health, Spedali Civili Hospital, Brescia, Italy
| | - Massimo Gennarelli
- Unit of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
- Genetic Unit, IRCCS Centro S. Giovanni di Dio Fatebenefratelli, Brescia, Italy
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16
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Bhandage AK, Jin Z, Korol SV, Shen Q, Pei Y, Deng Q, Espes D, Carlsson PO, Kamali-Moghaddam M, Birnir B. GABA Regulates Release of Inflammatory Cytokines From Peripheral Blood Mononuclear Cells and CD4 + T Cells and Is Immunosuppressive in Type 1 Diabetes. EBioMedicine 2018; 30:283-294. [PMID: 29627388 PMCID: PMC5952354 DOI: 10.1016/j.ebiom.2018.03.019] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 03/16/2018] [Accepted: 03/16/2018] [Indexed: 12/31/2022] Open
Abstract
The neurotransmitter γ-aminobutyric acid (GABA) is an extracellular signaling molecule in the brain and in pancreatic islets. Here, we demonstrate that GABA regulates cytokine secretion from human peripheral blood mononuclear cells (PBMCs) and CD4+ T cells. In anti-CD3 stimulated PBMCs, GABA (100 nM) inhibited release of 47 cytokines in cells from patients with type 1 diabetes (T1D), but only 16 cytokines in cells from nondiabetic (ND) individuals. CD4+ T cells from ND individuals were grouped into responder or non-responder T cells according to effects of GABA (100 nM, 500 nM) on the cell proliferation. In the responder T cells, GABA decreased proliferation, and inhibited secretion of 37 cytokines in a concentration-dependent manner. In the non-responder T cells, GABA modulated release of 8 cytokines. GABA concentrations in plasma from T1D patients and ND individuals were correlated with 10 cytokines where 7 were increased in plasma of T1D patients. GABA inhibited secretion of 5 of these cytokines from both T1D PBMCs and ND responder T cells. The results identify GABA as a potent regulator of both Th1- and Th2-type cytokine secretion from human PBMCs and CD4+ T cells where GABA generally decreases the secretion. GABA regulates cytokine secretion in anti-CD3-stimulated peripheral blood mononuclear cells (PBMCs) and CD4+ T cells. GABA inhibits secretion of 47 cytokines in PBMCs from type 1 diabetes patients. GABA regulates secretion of pro- and anti-inflammatory cytokines in a concentration-dependent manner.
GABA is a signal molecule in the brain, blood and pancreatic islets where it is secreted by the insulin-producing β cells. GABA has many roles in human islets including optimizing function and survival of β cells. Bhandage et al. now show that GABA is a potent regulator of secretion of both pro- and anti-inflammatory cytokines in stimulated immune cells. In type 1 diabetes the β-cell mass is diminished and thus the protective effect of GABA in the islets although not in blood. Targeting GABA signaling in diabetes mellitus is likely to be a part of the solution when curing diabetes.
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Affiliation(s)
- Amol K Bhandage
- Department of Neuroscience, Uppsala University, 75124 Uppsala, Sweden
| | - Zhe Jin
- Department of Neuroscience, Uppsala University, 75124 Uppsala, Sweden
| | - Sergiy V Korol
- Department of Neuroscience, Uppsala University, 75124 Uppsala, Sweden
| | - Qiujin Shen
- Department of Immunology, Genetics and Pathology, Science for Life laboratory, Uppsala University, 75124 Uppsala, Sweden
| | - Yu Pei
- Department of Cell and Molecular Biology, Karolinska Institute, 17165 Stockholm, Sweden
| | - Qiaolin Deng
- Department of Cell and Molecular Biology, Karolinska Institute, 17165 Stockholm, Sweden
| | - Daniel Espes
- Department of Medical Cell Biology, Uppsala University, 75124 Uppsala, Sweden; Department of Medical Sciences, Uppsala University, 75124 Uppsala, Sweden
| | - Per-Ola Carlsson
- Department of Medical Cell Biology, Uppsala University, 75124 Uppsala, Sweden; Department of Medical Sciences, Uppsala University, 75124 Uppsala, Sweden
| | - Masood Kamali-Moghaddam
- Department of Immunology, Genetics and Pathology, Science for Life laboratory, Uppsala University, 75124 Uppsala, Sweden
| | - Bryndis Birnir
- Department of Neuroscience, Uppsala University, 75124 Uppsala, Sweden.
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17
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Functional Characterization of Native, High-Affinity GABA A Receptors in Human Pancreatic β Cells. EBioMedicine 2018; 30:273-282. [PMID: 29606630 PMCID: PMC5952339 DOI: 10.1016/j.ebiom.2018.03.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 02/02/2018] [Accepted: 03/12/2018] [Indexed: 01/19/2023] Open
Abstract
In human pancreatic islets, the neurotransmitter γ-aminobutyric acid (GABA) is an extracellular signaling molecule synthesized by and released from the insulin-secreting β cells. The effective, physiological GABA concentration range within human islets is unknown. Here we use native GABAA receptors in human islet β cells as biological sensors and reveal that 100–1000 nM GABA elicit the maximal opening frequency of the single-channels. In saturating GABA, the channels desensitized and stopped working. GABA modulated insulin exocytosis and glucose-stimulated insulin secretion. GABAA receptor currents were enhanced by the benzodiazepine diazepam, the anesthetic propofol and the incretin glucagon-like peptide-1 (GLP-1) but not affected by the hypnotic zolpidem. In type 2 diabetes (T2D) islets, single-channel analysis revealed higher GABA affinity of the receptors. The findings reveal unique GABAA receptors signaling in human islets β cells that is GABA concentration-dependent, differentially regulated by drugs, modulates insulin secretion and is altered in T2D. In human islets GABA (≤μM) activates β cell-specific GABAA receptors that become supersensitive to GABA in type 2 diabetes. GABAA receptors activity in β cells is enhanced by diazepam, anesthetics, the incretin GLP-1 but not the hypnotic zolpidem. GABA modulates rate of insulin granule exocytosis and glucose-stimulated insulin secretion.
GABA is a signal molecule in the brain but is also secreted by the insulin-producing β cells in pancreatic islets. GABA has many roles in human islets that most aim at optimizing function and survival of β cells. In the report by Korol, Jin et al. the authors identify and characterize the molecular unit that GABA binds to in human β cells, the GABAA receptors. These receptors normally sensitive become super-sensitive to GABA in type 2 diabetes. The GABAA receptors regulate insulin secretion and can themselves be regulated by the anxiolytic diazepam, anesthetics, the incretin GLP-1 but not the hypnotic zolpidem. Targeting GABA signaling in human islets in diabetes mellitus is likely to be a part of the solution when curing diabetes.
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18
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Hasilo CP, Negi S, Allaeys I, Cloutier N, Rutman AK, Gasparrini M, Bonneil É, Thibault P, Boilard É, Paraskevas S. Presence of diabetes autoantigens in extracellular vesicles derived from human islets. Sci Rep 2017; 7:5000. [PMID: 28694505 PMCID: PMC5504025 DOI: 10.1038/s41598-017-04977-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 05/23/2017] [Indexed: 12/29/2022] Open
Abstract
Beta-cell (β-cell) injury is the hallmark of autoimmune diabetes. However, the mechanisms by which autoreactive responses are generated in susceptible individuals are not well understood. Extracellular vesicles (EV) are produced by mammalian cells under normal and stressed physiological states. They are an important part of cellular communication, and may serve a role in antigen processing and presentation. We hypothesized that isolated human islets in culture produce EV that contain diabetes autoantigens (DAA) from these otherwise normal, non-diabetic donors. Here we report the caspase-independent production of EV by human islets in culture, and the characterization of DAA glutamic acid decarboxylase 65 (GAD65) and zinc transporter 8 (ZnT8), as well as the β-cell resident glucose transporter 2 (Glut2), present within the EV.
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Affiliation(s)
- Craig P Hasilo
- Human Islet Transplant Laboratory, McGill University Health Centre, Montréal, Québec, Canada.,Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Sarita Negi
- Human Islet Transplant Laboratory, McGill University Health Centre, Montréal, Québec, Canada.,Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Isabelle Allaeys
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Québec, Québec, Canada
| | - Nathalie Cloutier
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Québec, Québec, Canada
| | - Alissa K Rutman
- Human Islet Transplant Laboratory, McGill University Health Centre, Montréal, Québec, Canada.,Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Marco Gasparrini
- Human Islet Transplant Laboratory, McGill University Health Centre, Montréal, Québec, Canada.,Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Éric Bonneil
- Institut de Recherche en Immunologie et en Cancérologie, Université de Montréal, Montréal, Québec, Canada
| | - Pierre Thibault
- Institut de Recherche en Immunologie et en Cancérologie, Université de Montréal, Montréal, Québec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Éric Boilard
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Québec, Québec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Steven Paraskevas
- Human Islet Transplant Laboratory, McGill University Health Centre, Montréal, Québec, Canada. .,Research Institute of the McGill University Health Centre, Montréal, Québec, Canada. .,Canadian National Transplant Research Program, Edmonton, Alberta, Canada.
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19
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Phelps EA, Cianciaruso C, Santo-Domingo J, Pasquier M, Galliverti G, Piemonti L, Berishvili E, Burri O, Wiederkehr A, Hubbell JA, Baekkeskov S. Advances in pancreatic islet monolayer culture on glass surfaces enable super-resolution microscopy and insights into beta cell ciliogenesis and proliferation. Sci Rep 2017; 7:45961. [PMID: 28401888 PMCID: PMC5388888 DOI: 10.1038/srep45961] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 03/08/2017] [Indexed: 12/16/2022] Open
Abstract
A robust and reproducible method for culturing monolayers of adherent and well-spread primary islet cells on glass coverslips is required for detailed imaging studies by super-resolution and live-cell microscopy. Guided by an observation that dispersed islet cells spread and adhere well on glass surfaces in neuronal co-culture and form a monolayer of connected cells, we demonstrate that in the absence of neurons, well-defined surface coatings combined with components of neuronal culture media collectively support robust attachment and growth of primary human or rat islet cells as monolayers on glass surfaces. The islet cell monolayer cultures on glass stably maintain distinct mono-hormonal insulin+, glucagon+, somatostatin+ and PP+ cells and glucose-responsive synchronized calcium signaling as well as expression of the transcription factors Pdx-1 and NKX-6.1 in beta cells. This technical advance enabled detailed observation of sub-cellular processes in primary human and rat beta cells by super-resolution microscopy. The protocol is envisaged to have broad applicability to sophisticated analyses of pancreatic islet cells that reveal new biological insights, as demonstrated by the identification of an in vitro protocol that markedly increases proliferation of primary beta cells and is associated with a reduction in ciliated, ostensibly proliferation-suppressed beta cells.
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Affiliation(s)
- Edward A Phelps
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Chiara Cianciaruso
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.,Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Jaime Santo-Domingo
- Nestlé Institute of Health Sciences S.A., EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Miriella Pasquier
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Gabriele Galliverti
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.,Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.,Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Lorenzo Piemonti
- Pancreatic Islet Processing Facility, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Ekaterine Berishvili
- Cell Isolation and Transplantation Center, Faculty of Medicine, Department of Surgery, Geneva University Hospitals and University of Geneva, CH-1211 Geneva, Switzerland
| | - Olivier Burri
- BioImaging and Optics Core Facility, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Andreas Wiederkehr
- Nestlé Institute of Health Sciences S.A., EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Jeffrey A Hubbell
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.,Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.,Institute for Molecular Engineering, University of Chicago, Chicago, IL 60615, USA
| | - Steinunn Baekkeskov
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.,Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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20
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Cianciaruso C, Phelps EA, Pasquier M, Hamelin R, Demurtas D, Alibashe Ahmed M, Piemonti L, Hirosue S, Swartz MA, De Palma M, Hubbell JA, Baekkeskov S. Primary Human and Rat β-Cells Release the Intracellular Autoantigens GAD65, IA-2, and Proinsulin in Exosomes Together With Cytokine-Induced Enhancers of Immunity. Diabetes 2017; 66:460-473. [PMID: 27872147 DOI: 10.2337/db16-0671] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/31/2016] [Indexed: 02/02/2023]
Abstract
The target autoantigens in several organ-specific autoimmune diseases, including type 1 diabetes (T1D), are intracellular membrane proteins, whose initial encounter with the immune system is poorly understood. Here we propose a new model for how these proteins can initiate autoimmunity. We found that rat and human pancreatic islets release the intracellular β-cell autoantigens in human T1D, GAD65, IA-2, and proinsulin in exosomes, which are taken up by and activate dendritic cells. Accordingly, the anchoring of GAD65 to exosome-mimetic liposomes strongly boosted antigen presentation and T-cell activation in the context of the human T1D susceptibility haplotype HLA-DR4. Cytokine-induced endoplasmic reticulum stress enhanced exosome secretion by β-cells; induced exosomal release of the immunostimulatory chaperones calreticulin, Gp96, and ORP150; and increased exosomal stimulation of antigen-presenting cells. We propose that stress-induced exosomal release of intracellular autoantigens and immunostimulatory chaperones may play a role in the initiation of autoimmune responses in T1D.
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Affiliation(s)
- Chiara Cianciaruso
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Edward A Phelps
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Miriella Pasquier
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Romain Hamelin
- Proteomics Core Facility, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Davide Demurtas
- Bio-Electron Microscopy Core Facility, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Mohamed Alibashe Ahmed
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Lorenzo Piemonti
- Diabetes Research Institute, Istituto di Ricovero e Cura a Carattere Scientifico, San Raffaele Scientific Institute, Milan, Italy
| | - Sachiko Hirosue
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Melody A Swartz
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Institute of Molecular Engineering, University of Chicago, Chicago, IL
| | - Michele De Palma
- Swiss Institute for Experimental Cancer Research, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Jeffrey A Hubbell
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Institute of Molecular Engineering, University of Chicago, Chicago, IL
| | - Steinunn Baekkeskov
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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21
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Urrutia M, Fernández S, González M, Vilches R, Rojas P, Vásquez M, Kurte M, Vega-Letter AM, Carrión F, Figueroa F, Rojas P, Irarrázabal C, Fuentealba RA. Overexpression of Glutamate Decarboxylase in Mesenchymal Stem Cells Enhances Their Immunosuppressive Properties and Increases GABA and Nitric Oxide Levels. PLoS One 2016; 11:e0163735. [PMID: 27662193 PMCID: PMC5035029 DOI: 10.1371/journal.pone.0163735] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 09/13/2016] [Indexed: 12/12/2022] Open
Abstract
The neurotransmitter GABA has been recently identified as a potent immunosuppressive agent that targets both innate and adaptive immune systems and prevents disease progression of several autoimmunity models. Mesenchymal stem cells (MSCs) are self-renewing progenitor cells that differentiate into various cell types under specific conditions, including neurons. In addition, MSC possess strong immunosuppressive capabilities. Upon cytokine priming, undifferentiated MSC suppress T-cell proliferation via cell-to-cell contact mechanisms and the secretion of soluble factors like nitric oxide, prostaglandin E2 and IDO. Although MSC and MSC-derived neuron-like cells express some GABAergic markers in vitro, the role for GABAergic signaling in MSC-mediated immunosuppression remains completely unexplored. Here, we demonstrate that pro-inflammatory cytokines selectively regulate GAD-67 expression in murine bone marrow-MSC. However, expression of GAD-65 is required for maximal GABA release by MSC. Gain of function experiments using GAD-67 and GAD-65 co-expression demonstrates that GAD increases immunosuppressive function in the absence of pro-inflammatory licensing. Moreover, GAD expression in MSC evokes an increase in both GABA and NO levels in the supernatants of co-cultured MSC with activated splenocytes. Notably, the increase in NO levels by GAD expression was not observed in cultures of isolated MSC expressing GAD, suggesting crosstalk between these two pathways in the setting of immunosuppression. These results indicate that GAD expression increases MSC-mediated immunosuppression via secretion of immunosuppressive agents. Our findings may help reconsider GABAergic activation in MSC for immunological disorders.
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Affiliation(s)
- Mariana Urrutia
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Sebastián Fernández
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Marisol González
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Rodrigo Vilches
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Pablo Rojas
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Manuel Vásquez
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Mónica Kurte
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Ana María Vega-Letter
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Flavio Carrión
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Fernando Figueroa
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Patricio Rojas
- Departamento de Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Carlos Irarrázabal
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Rodrigo A. Fuentealba
- Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
- * E-mail:
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22
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Phelps EA, Cianciaruso C, Michael IP, Pasquier M, Kanaani J, Nano R, Lavallard V, Billestrup N, Hubbell JA, Baekkeskov S. Aberrant Accumulation of the Diabetes Autoantigen GAD65 in Golgi Membranes in Conditions of ER Stress and Autoimmunity. Diabetes 2016; 65:2686-99. [PMID: 27284108 PMCID: PMC5001175 DOI: 10.2337/db16-0180] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/27/2016] [Indexed: 02/06/2023]
Abstract
Pancreatic islet β-cells are particularly susceptible to endoplasmic reticulum (ER) stress, which is implicated in β-cell dysfunction and loss during the pathogenesis of type 1 diabetes (T1D). The peripheral membrane protein GAD65 is an autoantigen in human T1D. GAD65 synthesizes γ-aminobutyric acid, an important autocrine and paracrine signaling molecule and a survival factor in islets. We show that ER stress in primary β-cells perturbs the palmitoylation cycle controlling GAD65 endomembrane distribution, resulting in aberrant accumulation of the palmitoylated form in trans-Golgi membranes. The palmitoylated form has heightened immunogenicity, exhibiting increased uptake by antigen-presenting cells and T-cell stimulation compared with the nonpalmitoylated form. Similar accumulation of GAD65 in Golgi membranes is observed in human β-cells in pancreatic sections from GAD65 autoantibody-positive individuals who have not yet progressed to clinical onset of T1D and from patients with T1D with residual β-cell mass and ongoing T-cell infiltration of islets. We propose that aberrant accumulation of immunogenic GAD65 in Golgi membranes facilitates inappropriate presentation to the immune system after release from stressed and/or damaged β-cells, triggering autoimmunity.
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Affiliation(s)
- Edward A Phelps
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Chiara Cianciaruso
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Iacovos P Michael
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Miriella Pasquier
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Jamil Kanaani
- Departments of Medicine, Microbiology and Immunology and Diabetes Center, University of California San Francisco, San Francisco, CA
| | - Rita Nano
- Diabetes Research Institute, IRCCS, Pancreatic Islet Processing Facility, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Vanessa Lavallard
- Cell Isolation and Transplantation Center, Faculty of Medicine, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Nils Billestrup
- Section of Cellular and Metabolic Research, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jeffrey A Hubbell
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Institute for Molecular Engineering, University of Chicago, Chicago, IL
| | - Steinunn Baekkeskov
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Graduate Program in Biotechnology and Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Departments of Medicine, Microbiology and Immunology and Diabetes Center, University of California San Francisco, San Francisco, CA
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23
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Abstract
Islet autoantibodies are the main markers of pancreatic autoimmunity in type 1 diabetes (T1D). Islet autoantibodies recognize insulin (IAA), glutamic acid decarboxylase (GADA), protein phosphatase-like IA-2 (IA-2A), and ZnT8 (ZnT8A), all antigens that are found on secretory granules within pancreatic beta cells. Islet antibodies, measured by sensitive and specific liquid phase assays, are the key parameters of the autoimmune response monitored for diagnostics or prognostics in patients with T1D or for disease prediction in at-risk individuals before T1D onset. Islet autoantibodies have been the main tool used to explore the natural history of T1D; this review summarizes the current knowledge about the autoantigens and the phenotype of islets autoantibodies acquired in large prospective studies from birth in children at risk of developing T1D.
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Affiliation(s)
- Vito Lampasona
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy.
- Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy.
| | - Daniela Liberati
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy
- Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy
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24
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Otter S, Lammert E. Exciting Times for Pancreatic Islets: Glutamate Signaling in Endocrine Cells. Trends Endocrinol Metab 2016; 27:177-188. [PMID: 26740469 DOI: 10.1016/j.tem.2015.12.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/11/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023]
Abstract
Glutamate represents a key excitatory neurotransmitter in the central nervous system, and also modulates the function and viability of endocrine cells in pancreatic islets. In insulin-secreting beta cells, glutamate acts as an intracellular messenger, and its transport into secretory granules promotes glucose- and incretin-stimulated insulin secretion. Mitochondrial degradation of glutamate also contributes to insulin release when glutamate dehydrogenase is allosterically activated. It also signals extracellularly via glutamate receptors (AMPA and NMDA receptors) to modulate glucagon, insulin and somatostatin secretion, and islet cell survival. Its degradation products, GABA and γ-hydroxybutyrate, are released and also influence islet cell behavior. Thus, islet glutamate receptors, such as the NMDA receptors, might serve as possible drug targets to develop new medications for adjunct treatment of diabetes.
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Affiliation(s)
- Silke Otter
- Institute of Metabolic Physiology, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; Institute for Beta Cell Biology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research, and German Center for Diabetes Research (DZD e.V.), Düsseldorf, Germany
| | - Eckhard Lammert
- Institute of Metabolic Physiology, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; Institute for Beta Cell Biology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research, and German Center for Diabetes Research (DZD e.V.), Düsseldorf, Germany.
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25
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Kanda H, Kanao M, Liu S, Yi H, Iida T, Levitt RC, Candiotti KA, Lubarsky DA, Hao S. HSV vector-mediated GAD67 suppresses neuropathic pain induced by perineural HIV gp120 in rats through inhibition of ROS and Wnt5a. Gene Ther 2016; 23:340-8. [PMID: 26752351 PMCID: PMC4824655 DOI: 10.1038/gt.2016.3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 11/22/2015] [Accepted: 12/31/2015] [Indexed: 12/19/2022]
Abstract
Human immunodeficiency virus (HIV)-related neuropathic pain is a debilitating chronic condition that is severe and unrelenting. Despite the extensive research, the exact neuropathological mechanisms remain unknown, which hinders our ability to develop effective treatments. Loss of GABAergic tone may play an important role in the neuropathic pain state. Glutamic acid decarboxylase 67 (GAD67) is one of isoforms that catalyze GABA synthesis. Here, we used recombinant herpes simplex virus (HSV-1) vectors that encode gad1 gene to evaluate the therapeutic potential of GAD67 in peripheral HIV gp120-induced neuropathic pain in rats. We found that 1) subcutaneous inoculation of the HSV vectors expressing GAD67 attenuated mechanical allodynia in the model of HIV gp120-induced neuropathic pain, 2) the anti-allodynic effect of GAD67 was reduced by GABA-A and-B receptors antagonists, 3) HSV vectors expressing GAD67 reversed the lowered GABA-IR expression, and 4) the HSV vectors expressing GAD67 suppressed the upregulated mitochondrial superoxide and Wnt5a in the spinal dorsal horn. Taken together, our studies support the concept that recovering GABAergic tone by the HSV vectors may reverse HIV-associated neuropathic pain through suppressing mitochondrial superoxide and Wnt5a. Our studies provide validation of HSV-mediated GAD67 gene therapy in the treatment of HIV-related neuropathic pain.
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Affiliation(s)
- H Kanda
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Anesthesiology, Asahikawa Medical University, Asahikawa, Japan
| | - M Kanao
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Anesthesiology, Asahikawa Medical University, Asahikawa, Japan
| | - S Liu
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - H Yi
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - T Iida
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Anesthesiology, Asahikawa Medical University, Asahikawa, Japan
| | - R C Levitt
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA.,Hussman Institute of Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA.,Veterans Affairs Medical Center, Miami, FL, USA
| | - K A Candiotti
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - D A Lubarsky
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - S Hao
- Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL, USA
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26
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Microtubules Negatively Regulate Insulin Secretion in Pancreatic β Cells. Dev Cell 2016; 34:656-68. [PMID: 26418295 DOI: 10.1016/j.devcel.2015.08.020] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 06/04/2015] [Accepted: 08/26/2015] [Indexed: 01/06/2023]
Abstract
For glucose-stimulated insulin secretion (GSIS), insulin granules have to be localized close to the plasma membrane. The role of microtubule-dependent transport in granule positioning and GSIS has been debated. Here, we report that microtubules, counterintuitively, restrict granule availability for secretion. In β cells, microtubules originate at the Golgi and form a dense non-radial meshwork. Non-directional transport along these microtubules limits granule dwelling at the cell periphery, restricting granule availability for secretion. High glucose destabilizes microtubules, decreasing their density; such local microtubule depolymerization is necessary for GSIS, likely because granule withdrawal from the cell periphery becomes inefficient. Consistently, microtubule depolymerization by nocodazole blocks granule withdrawal, increases their concentration at exocytic sites, and dramatically enhances GSIS in vitro and in mice. Furthermore, glucose-driven MT destabilization is balanced by new microtubule formation, which likely prevents over-secretion. Importantly, microtubule density is greater in dysfunctional β cells of diabetic mice.
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