101
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Affiliation(s)
- Ralf P. Brandes
- From the Institut für Kardiovaskuläre Physiologie, Fachbereich Medizin der Goethe-Universität, Theodor-Stern Kai 7, 60590 Frankfurt, Germany
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102
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Feeding rumen-protected gamma-aminobutyric acid enhances the immune response and antioxidant status of heat-stressed lactating dairy cows. J Therm Biol 2016; 60:103-8. [DOI: 10.1016/j.jtherbio.2016.06.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 06/12/2016] [Accepted: 06/14/2016] [Indexed: 11/19/2022]
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103
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Nantes JC, Zhong J, Holmes SA, Narayanan S, Lapierre Y, Koski L. Cortical Damage and Disability in Multiple Sclerosis: Relation to Intracortical Inhibition and Facilitation. Brain Stimul 2016; 9:566-73. [DOI: 10.1016/j.brs.2016.01.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 12/11/2015] [Accepted: 01/05/2016] [Indexed: 10/22/2022] Open
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104
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Patterson E, Ryan PM, Cryan JF, Dinan TG, Ross RP, Fitzgerald GF, Stanton C. Gut microbiota, obesity and diabetes. Postgrad Med J 2016; 92:286-300. [PMID: 26912499 DOI: 10.1136/postgradmedj-2015-133285] [Citation(s) in RCA: 315] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/28/2016] [Indexed: 02/06/2023]
Abstract
The central role of the intestinal microbiota in the progression and, equally, prevention of metabolic dysfunction is becoming abundantly apparent. The symbiotic relationship between intestinal microbiota and host ensures appropriate development of the metabolic system in humans. However, disturbances in composition and, in turn, functionality of the intestinal microbiota can disrupt gut barrier function, a trip switch for metabolic endotoxemia. This low-grade chronic inflammation, brought about by the influx of inflammatory bacterial fragments into circulation through a malfunctioning gut barrier, has considerable knock-on effects for host adiposity and insulin resistance. Conversely, recent evidence suggests that there are certain bacterial species that may interact with host metabolism through metabolite-mediated stimulation of enteric hormones and other systems outside of the gastrointestinal tract, such as the endocannabinoid system. When the abundance of these keystone species begins to decline, we see a collapse of the symbiosis, reflected in a deterioration of host metabolic health. This review will investigate the intricate axis between the microbiota and host metabolism, while also addressing the promising and novel field of probiotics as metabolic therapies.
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Affiliation(s)
- Elaine Patterson
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Food Biosciences Department, Teagasc Food Research Centre, Fermoy, Co. Cork, Ireland
| | - Paul M Ryan
- Food Biosciences Department, Teagasc Food Research Centre, Fermoy, Co. Cork, Ireland School of Microbiology, University College Cork, Co. Cork, Ireland
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Department of Anatomy and Neuroscience, University College Cork, Co. Cork, Ireland
| | - Timothy G Dinan
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Department of Psychiatry and Neurobehavioural Science, University College Cork, Co. Cork, Ireland
| | - R Paul Ross
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland College of Science, Engineering and Food Science, University College Cork, Co. Cork, Ireland
| | - Gerald F Fitzgerald
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland School of Microbiology, University College Cork, Co. Cork, Ireland
| | - Catherine Stanton
- APC Microbiome Institute, University College Cork, Co. Cork, Ireland Food Biosciences Department, Teagasc Food Research Centre, Fermoy, Co. Cork, Ireland
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105
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Nantes JC, Zhong J, Holmes SA, Whatley B, Narayanan S, Lapierre Y, Arnold DL, Koski L. Intracortical inhibition abnormality during the remission phase of multiple sclerosis is related to upper limb dexterity and lesions. Clin Neurophysiol 2016; 127:1503-1511. [DOI: 10.1016/j.clinph.2015.08.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 07/24/2015] [Accepted: 08/24/2015] [Indexed: 11/24/2022]
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106
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A study on the involvement of GABA-transaminase in MCT induced pulmonary hypertension. Pulm Pharmacol Ther 2016; 36:10-21. [DOI: 10.1016/j.pupt.2015.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 11/04/2015] [Accepted: 11/12/2015] [Indexed: 12/15/2022]
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107
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γ-Aminobutyric acid-rich yogurt fermented by Streptococcus salivarius subsp. thermophiles fmb5 apprars to have anti-diabetic effect on streptozotocin-induced diabetic mice. J Funct Foods 2016. [DOI: 10.1016/j.jff.2015.10.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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108
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Gross AM, Kreisberg JF, Ideker T. Analysis of Matched Tumor and Normal Profiles Reveals Common Transcriptional and Epigenetic Signals Shared across Cancer Types. PLoS One 2015; 10:e0142618. [PMID: 26555223 PMCID: PMC4640835 DOI: 10.1371/journal.pone.0142618] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/23/2015] [Indexed: 12/21/2022] Open
Abstract
To identify the transcriptional regulatory changes that are most widespread in solid tumors, we performed a pan-cancer analysis using over 600 pairs of tumors and adjacent normal tissues profiled in The Cancer Genome Atlas (TCGA). Frequency of upregulation was calculated across mRNA expression levels, microRNA expression levels and CpG methylation sites and is provided here as a resource. Frequent tumor-associated alterations were identified using a simple statistical approach. Many of the identified changes were consistent with the increased rate of cell division in cancer, such as the overexpression of cell cycle genes and hypermethylation of PRC2 binding sites. However, we also identified proliferation-independent alterations, which highlight novel pathways essential to tumor formation. Nearly all of the GABA receptors are frequently downregulated, with the gene encoding the delta subunit (GABRD) strongly upregulated as the notable exception. Metabolic genes are also frequently downregulated, particularly alcohol dehydrogenases and others consistent with the decreased role of oxidative phosphorylation in cancerous cells. Alterations in the composition of GABA receptors and metabolism may play a key role in the differentiation of cancer cells, independent of proliferation.
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Affiliation(s)
- Andrew M. Gross
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, California, United States of America
| | - Jason F. Kreisberg
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Trey Ideker
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, California, United States of America
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
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109
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Li J, Zhang Z, Liu X, Wang Y, Mao F, Mao J, Lu X, Jiang D, Wan Y, Lv JY, Cao G, Zhang J, Zhao N, Atkinson M, Greiner DL, Prud'homme GJ, Jiao Z, Li Y, Wang Q. Study of GABA in Healthy Volunteers: Pharmacokinetics and Pharmacodynamics. Front Pharmacol 2015; 6:260. [PMID: 26617516 PMCID: PMC4639630 DOI: 10.3389/fphar.2015.00260] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 10/20/2015] [Indexed: 01/13/2023] Open
Abstract
Preclinical studies show that GABA exerts anti-diabetic effects in rodent models of type 1 diabetes. Because little is known about its absorption and effects in humans, we investigated the pharmacokinetics and pharmacodynamics of GABA in healthy volunteers. Twelve subjects were subjected to an open-labeled, three-period trial involving sequential oral administration of placebo, 2 g GABA once, and 2 g GABA three times/day for 7 days, with a 7-day washout between each period. GABA was rapidly absorbed (Tmax: 0.5 ~ 1 h) with the half-life (t1/2) of 5 h. No accumulation was observed after repeated oral GABA administration for 7 days. Remarkably, GABA significantly increased circulating insulin levels in the subjects under either fasting (1.6-fold, single dose; 2.0-fold, repeated dose; p < 0.01) or fed conditions (1.4-fold, single dose; 1.6-fold, repeated dose; p < 0.01). GABA also increased glucagon levels only under fasting conditions (1.3-fold, single dose, p < 0.05; 1.5-fold, repeated dose, p < 0.01). However, there were no significant differences in the insulin-to-glucagon ratio and no significant change in glucose levels in these healthy subjects during the study period. Importantly, GABA significantly decreased glycated albumin levels in the repeated dosing period. Subjects with repeated dosing showed an elevated incidence of minor adverse events in comparison to placebo or the single dosing period, most notably transient discomforts such as dizziness and sore throat. However, there were no serious adverse events observed throughout the study. Our data show that GABA is rapidly absorbed and tolerated in human beings; its endocrine effects, exemplified by increasing islet hormonal secretion, suggest potential therapeutic benefits for diabetes.
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Affiliation(s)
- Junfeng Li
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Zhaoyun Zhang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Xiaoxia Liu
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Yi Wang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Fei Mao
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Junjun Mao
- Department of Pharmacy, Huashan Hospital, Fudan University Shanghai, China
| | - Xiaolan Lu
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Dongdong Jiang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Yun Wan
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Jia-Ying Lv
- Department of Biostatistics, School of Public Health, Fudan University Shanghai, China
| | - Guoying Cao
- Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Institute of Antibiotics, Huashan Hospital, Fudan University Shanghai, China
| | - Jing Zhang
- Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Institute of Antibiotics, Huashan Hospital, Fudan University Shanghai, China
| | - Naiqing Zhao
- Department of Biostatistics, School of Public Health, Fudan University Shanghai, China
| | - Mark Atkinson
- Department of Pathology, College of Medicine, University of Florida Gainesville, FL, USA
| | - Dale L Greiner
- Department of Molecular Medicine, University of Massachusetts Medical School Worcester, MA, USA
| | - Gerald J Prud'homme
- Department of Laboratory Medicine and Pathobiology, Keenan Research Centre for Biomedical Science of St. Michael's Hospital, University of Toronto Toronto, ON, Canada
| | - Zheng Jiao
- Department of Pharmacy, Huashan Hospital, Fudan University Shanghai, China
| | - Yiming Li
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China
| | - Qinghua Wang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University Shanghai, China ; Division of Endocrinology and Metabolism, The Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital Toronto, ON, Canada ; Department of Physiology and Medicine, University of Toronto ON, Canada
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110
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Prud'homme GJ, Glinka Y, Wang Q. Immunological GABAergic interactions and therapeutic applications in autoimmune diseases. Autoimmun Rev 2015; 14:1048-56. [DOI: 10.1016/j.autrev.2015.07.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 07/17/2015] [Indexed: 12/20/2022]
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111
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Liu J, Huang D, Xu J, Tong J, Wang Z, Huang L, Yang Y, Bai X, Wang P, Suo H, Ma Y, Yu M, Fei J, Huang F. Tiagabine Protects Dopaminergic Neurons against Neurotoxins by Inhibiting Microglial Activation. Sci Rep 2015; 5:15720. [PMID: 26499517 PMCID: PMC4620555 DOI: 10.1038/srep15720] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 10/02/2015] [Indexed: 01/04/2023] Open
Abstract
Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative disorders such as Parkinson's disease (PD). γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, has recently been shown to play an inhibitory role in the immune system. Tiagabine, a piperidine derivative, enhances GABAergic transmission by inhibiting GABA transporter 1 (GAT 1). In the present study, we found that tiagabine pretreatment attenuated microglial activation, provided partial protection to the nigrostriatal axis and improved motor deficits in a methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. The protective function of tiagabine was abolished in GAT 1 knockout mice that were challenged with MPTP. In an alternative PD model, induced by intranigral infusion of lipopolysaccharide (LPS), microglial suppression and subsequent neuroprotective effects of tiagabine were demonstrated. Furthermore, the LPS-induced inflammatory activation of BV-2 microglial cells and the toxicity of conditioned medium toward SH-SY5Y cells were inhibited by pretreatment with GABAergic drugs. The attenuation of the nuclear translocation of nuclear factor κB (NF-κB) and the inhibition of the generation of inflammatory mediators were the underlying mechanisms. Our results suggest that tiagabine acts as a brake for nigrostriatal microglial activation and that it might be a novel therapeutic approach for PD.
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Affiliation(s)
- Jie Liu
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.,Research Center for Translational Medicine and Institute of Heart Failure, East Hospital, Tongji University, Shanghai 200120, China
| | - Dongping Huang
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Jing Xu
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Jiabin Tong
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Zishan Wang
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Li Huang
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Yufang Yang
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Xiaochen Bai
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Pan Wang
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Haiyun Suo
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Yuanyuan Ma
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Mei Yu
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Jian Fei
- School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China.,Shanghai Research Center for Model Organisms, Pudong, Shanghai 201203, China
| | - Fang Huang
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.,Key Laboratory of Smart Drug Delivery, Fudan University, Ministry of Education, Shanghai 201203, China
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112
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Huang S, Mao J, Wei B, Pei G. The anti-spasticity drug baclofen alleviates collagen-induced arthritis and regulates dendritic cells. J Cell Physiol 2015; 230:1438-47. [PMID: 25556830 DOI: 10.1002/jcp.24884] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/05/2014] [Indexed: 12/27/2022]
Abstract
Baclofen is used clinically as a drug that treats spasticity, which is a syndrome characterized by excessive contraction of the muscles and hyperflexia in the central nervous system (CNS), by activating GABA(B) receptors (GABA(B)Rs). Baclofen was recently reported to desensitize chemokine receptors and to suppress inflammation through the activation of GABA(B)Rs. GABA(B)Rs are expressed in various immune cells, but the functions of these receptors in autoimmune diseases remain largely unknown. In this study, we investigated the effects of baclofen in murine collagen-induced arthritis (CIA). Oral administration of baclofen alleviated the clinical development of CIA, with a reduced number of IL-17-producing T helper 17 (T(H)17) cells. In addition, baclofen treatment suppressed dendritic cell (DC)-primed T(H)17 cell differentiation by reducing the production of IL-6 by DCs in vitro. Furthermore, the pharmacological and genetic blockade of GABA(B)Rs in DCs weakened the effects of baclofen, indicating that GABA(B)Rs are the molecular targets of baclofen on DCs. Thus, our findings revealed a potential role for baclofen in the treatment of CIA, as well as a previously unknown signaling pathway that regulates DC function.
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Affiliation(s)
- Shichao Huang
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, P. R. China
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113
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Abstract
The brain under immunological attack does not surrender quietly. Investigation of brain lesions in multiple sclerosis (MS) reveals a coordinated molecular response involving various proteins and small molecules ranging from heat shock proteins to small lipids, neurotransmitters, and even gases, which provide protection and foster repair. Reduction of inflammation serves as a necessary prerequisite for effective recovery and regeneration. Remarkably, many lesion-resident molecules activate pathways leading to both suppression of inflammation and promotion of repair mechanisms. These guardian molecules and their corresponding physiologic pathways could potentially be exploited to silence inflammation and repair the injured and degenerating brain and spinal cord in both relapsing-remitting and progressive forms of MS and may be beneficial in other neurologic and psychiatric conditions.
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114
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Barragan A, Weidner JM, Jin Z, Korpi ER, Birnir B. GABAergic signalling in the immune system. Acta Physiol (Oxf) 2015; 213:819-27. [PMID: 25677654 DOI: 10.1111/apha.12467] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 12/12/2014] [Accepted: 02/06/2015] [Indexed: 01/12/2023]
Abstract
The GABAergic system is the main inhibitory neurotransmitter system in the central nervous system (CNS) of vertebrates. Signalling of the transmitter γ-aminobutyric acid (GABA) via GABA type A receptor channels or G-protein-coupled type B receptors is implicated in multiple CNS functions. Recent findings have implicated the GABAergic system in immune cell functions, inflammatory conditions and diseases in peripheral tissues. Interestingly, the specific effects may vary between immune cell types, with stage of activation and be altered by infectious agents. GABA/GABA-A receptor-mediated immunomodulatory functions have been unveiled in immune cells, being present in T lymphocytes and regulating the migration of Toxoplasma-infected dendritic cells. The GABAergic system may also play a role in the regulation of brain resident immune cells, the microglial cells. Activation of microglia appears to regulate the function of GABAergic neurotransmission in neighbouring neurones through changes induced by secretion of brain-derived neurotrophic factor. The neurotransmitter-driven immunomodulation is a new but rapidly growing field of science. Herein, we review the present knowledge of the GABA signalling in immune cells of the periphery and the CNS and raise questions for future research.
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Affiliation(s)
- A. Barragan
- Department of Molecular Biosciences; The Wenner-Gren Institute; Stockholm University; Stockholm Sweden
- Department of Medicine; Center for Infectious Medicine; Karolinska Institutet; Stockholm Sweden
| | - J. M. Weidner
- Department of Molecular Biosciences; The Wenner-Gren Institute; Stockholm University; Stockholm Sweden
- Department of Medicine; Center for Infectious Medicine; Karolinska Institutet; Stockholm Sweden
| | - Z. Jin
- Department of Neuroscience; Uppsala University; Uppsala Sweden
| | - E. R. Korpi
- Department of Pharmacology; Faculty of Medicine; University of Helsinki; Helsinki Finland
- Department of Pharmacology; Yong Loo Lin School of Medicine; National University Health System; Neurobiology and Ageing Programme; Life Sciences Institute; National University of Singapore, and SINAPSE, Singapore Institute for Neurotechnology; Singapore
| | - B. Birnir
- Department of Neuroscience; Uppsala University; Uppsala Sweden
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115
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Auteri M, Zizzo MG, Serio R. GABA and GABA receptors in the gastrointestinal tract: from motility to inflammation. Pharmacol Res 2015; 93:11-21. [PMID: 25526825 DOI: 10.1016/j.phrs.2014.12.001] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/28/2014] [Accepted: 12/01/2014] [Indexed: 12/16/2022]
Abstract
Although an extensive body of literature confirmed γ-aminobutyric acid (GABA) as mediator within the enteric nervous system (ENS) controlling gastrointestinal (GI) function, the true significance of GABAergic signalling in the gut is still a matter of debate. GABAergic cells in the bowel include neuronal and endocrine-like cells, suggesting GABA as modulator of both motor and secretory GI activity. GABA effects in the GI tract depend on the activation of ionotropic GABAA and GABAC receptors and metabotropic GABAB receptors, resulting in a potential noteworthy regulation of both the excitatory and inhibitory signalling in the ENS. However, the preservation of GABAergic signalling in the gut could not be limited to the maintenance of physiologic intestinal activity. Indeed, a series of interesting studies have suggested a potential key role of GABA in the promising field of neuroimmune interaction, being involved in the modulation of immune cell activity associated with different systemic and enteric inflammatory conditions. Given the urgency of novel therapeutic strategies against chronic immunity-related pathologies, i.e. multiple sclerosis and Inflammatory Bowel Disease, an in-depth comprehension of the enteric GABAergic system in health and disease could provide the basis for new clinical application of nerve-driven immunity. Hence, in the attempt to drive novel researches addressing both the physiological and pathological importance of the GABAergic signalling in the gut, we summarized current evidence on GABA and GABA receptor function in the different parts of the GI tract, with particular focus on the potential involvement in the modulation of GI motility and inflammation.
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Affiliation(s)
- Michelangelo Auteri
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Università di Palermo, Viale delle Scienze, I-90128 Palermo, Italy
| | - Maria Grazia Zizzo
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Università di Palermo, Viale delle Scienze, I-90128 Palermo, Italy
| | - Rosa Serio
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Università di Palermo, Viale delle Scienze, I-90128 Palermo, Italy.
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116
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Bhandage AK, Hellgren C, Jin Z, Olafsson EB, Sundström-Poromaa I, Birnir B. Expression of GABA receptors subunits in peripheral blood mononuclear cells is gender dependent, altered in pregnancy and modified by mental health. Acta Physiol (Oxf) 2015; 213:575-85. [PMID: 25529063 DOI: 10.1111/apha.12440] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 12/05/2014] [Accepted: 12/15/2014] [Indexed: 12/31/2022]
Abstract
AIM The concept of nerve-driven immunity recognizes a link between the nervous and the immune system. γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain, and receptors activated by GABA can be expressed by immune cells. Here, we examined whether the expression of GABA receptors and chloride transporters in human peripheral blood mononuclear cells (PBMCs) was influenced by gender, pregnancy or mental health. METHODS We used RT-qPCR to determine the mRNA expression level in PBMCs from men (n = 16), non-pregnant women (n = 19), healthy pregnant women (n = 27) and depressed pregnant women (n = 15). RESULTS The ρ2 subunit had the most prominent expression level of the GABA-A receptor subunits in all samples. The δ and ρ2 subunits were up-regulated by pregnancy, whereas the ε subunit was more frequently expressed in healthy pregnant women than non-pregnant women who, in turn, commonly expressed the α6 and the γ2 subunits. The β1 and ε subunits expression was altered by depression in pregnant women. The GABA-B1 receptor was up-regulated by depression in pregnant women, while the transporters NKCC1 and KCC4 were down-regulated by pregnancy. The changes recorded in the mRNA expression levels imply participation of GABA receptors in establishing and maintaining tolerance in pregnancy. Importantly, the correlation of mental health with the expression of specific receptor subunits reveals a connection between the immune cells and the brain. Biomarkers for mental health may be identified in PBMCs. CONCLUSION The results demonstrate the impact gender, pregnancy and mental health have on the expression of GABA receptors and chloride transporters expressed in human PBMCs.
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Affiliation(s)
- A. K. Bhandage
- Department of Neuroscience; Uppsala University; Uppsala Sweden
| | - C. Hellgren
- Department of Women's and Children's Health; Uppsala University; Uppsala Sweden
| | - Z. Jin
- Department of Neuroscience; Uppsala University; Uppsala Sweden
| | - E. B. Olafsson
- Department of Neuroscience; Uppsala University; Uppsala Sweden
- Department of Molecular Biosciences; Stockholm University; Stockholm Sweden
| | | | - B. Birnir
- Department of Neuroscience; Uppsala University; Uppsala Sweden
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117
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A century of pavlovian experiments forming a circuit from the elucidation of neural reflexes to pharmaceuticals and electroceuticals to treat diseases. Brain Behav Immun 2015; 44:17-8. [PMID: 25451616 DOI: 10.1016/j.bbi.2014.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 09/28/2014] [Indexed: 11/21/2022] Open
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118
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Tuntipopipat S, Muangnoi C, Thiyajai P, Srichamnong W, Charoenkiatkul S, Praengam K. A bioaccessible fraction of parboiled germinated brown rice exhibits a higher anti-inflammatory activity than that of brown rice. Food Funct 2015; 6:1480-8. [DOI: 10.1039/c4fo01194e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Parboiled germinated brown rice (PGBR) has been suggested as a functional food because it is relatively rich in a number of nutrients and health promoting compounds.
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Affiliation(s)
| | | | - Parunya Thiyajai
- Institute of Nutrition
- Mahidol University
- Nakhonpathom 73170
- Thailand
| | | | | | - Kemika Praengam
- Institute of Nutrition
- Mahidol University
- Nakhonpathom 73170
- Thailand
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Wan Y, Wang Q, Prud’homme GJ. GABAergic system in the endocrine pancreas: a new target for diabetes treatment. Diabetes Metab Syndr Obes 2015; 8:79-87. [PMID: 25678807 PMCID: PMC4322886 DOI: 10.2147/dmso.s50642] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Excessive loss of functional pancreatic β-cell mass, mainly due to apoptosis, is a major factor in the development of hyperglycemia in both type 1 and type 2 diabetes (T1D and T2D). In T1D, β-cells are destroyed by immunological mechanisms. In T2D, while metabolic factors are known to contribute to β-cell failure and subsequent apoptosis, mounting evidence suggests that islet inflammation also plays an important role in the loss of β-cell mass. Therefore, it is of great importance for clinical intervention to develop new therapies. γ-Aminobutyric acid (GABA), a major neurotransmitter, is also produced by islet β-cells, where it functions as an important intraislet transmitter in regulating islet-cell secretion and function. Importantly, recent studies performed in rodents, including in vivo studies of xenotransplanted human islets, reveal that GABA exerts β-cell regenerative effects. Moreover, it protects β-cells against apoptosis induced by cytokines, drugs, and other stresses, and has anti-inflammatory and immunoregulatory activities. It ameliorates the manifestations of diabetes in preclinical models, suggesting potential applications for the treatment of diabetic patients. This review outlines the actions of GABA relevant to β-cell regeneration, including its signaling mechanisms and potential interactions with other mediators. These studies increase our understanding of the regenerative processes of pancreatic β-cells, and help pave the way for the development of regenerative medicine for diabetes.
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Affiliation(s)
- Yun Wan
- Department of Endocrinology and Metabolism, Huashan Hospital, Medical College, Fudan University, Shanghai, People’s Republic of China
| | - Qinghua Wang
- Department of Endocrinology and Metabolism, Huashan Hospital, Medical College, Fudan University, Shanghai, People’s Republic of China
- Division of Endocrinology and Metabolism, Keenan Research Centre for Biomedical Science of St Michael’s Hospital, Toronto, ON, Canada
- Departments of Physiology and Medicine, Faculty of Medicine, Toronto, ON, Canada
- Correspondence: Qinghua Wang, Division of Endocrinology and Metabolism, St Michael’s Hospital, 30 Bond Street, Toronto, ON M5B 1W8, Canada, Tel +1 416 864 6060 ext 77 610, Fax +1 416 864 5140, Email
| | - Gerald 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, St Michael’s Hospital, Toronto, ON, Canada
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Abstract
Ion channels and transporters mediate the transport of charged ions across hydrophobic lipid membranes. In immune cells, divalent cations such as calcium, magnesium, and zinc have important roles as second messengers to regulate intracellular signaling pathways. By contrast, monovalent cations such as sodium and potassium mainly regulate the membrane potential, which indirectly controls the influx of calcium and immune cell signaling. Studies investigating human patients with mutations in ion channels and transporters, analysis of gene-targeted mice, or pharmacological experiments with ion channel inhibitors have revealed important roles of ionic signals in lymphocyte development and in innate and adaptive immune responses. We here review the mechanisms underlying the function of ion channels and transporters in lymphocytes and innate immune cells and discuss their roles in lymphocyte development, adaptive and innate immune responses, and autoimmunity, as well as recent efforts to develop pharmacological inhibitors of ion channels for immunomodulatory therapy.
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Affiliation(s)
- Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY 10016
| | - Heike Wulff
- Department of Pharmacology, School of Medicine, University of California, Davis, California 95616
| | - Edward Y. Skolnik
- Division of Nephrology, New York University School of Medicine, New York, NY 10016
- Department of Molecular Pathogenesis, New York University School of Medicine, New York, NY 10016
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY 10016
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GABA protects pancreatic beta cells against apoptosis by increasing SIRT1 expression and activity. Biochem Biophys Res Commun 2014; 452:649-54. [PMID: 25193706 DOI: 10.1016/j.bbrc.2014.08.135] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 08/25/2014] [Indexed: 02/08/2023]
Abstract
We have previously shown that GABA protects pancreatic islet cells against apoptosis and exerts anti-inflammatory effects. Notably, GABA inhibited the activation of NF-κB in both islet cells and lymphocytes. NF-κB activation is detrimental to beta cells by promoting apoptosis. However, the mechanisms by which GABA mediates these effects are unknown. Because the above-mentioned effects mimic the activity of sirtuin 1 (SIRT1) in beta cells, we investigated whether it is involved. SIRT1 is an NAD(+)-dependent deacetylase that enhances insulin secretion, and counteracts inflammatory signals in beta cells. We found that the incubation of a clonal beta-cell line (rat INS-1) with GABA increased the expression of SIRT1, as did GABA receptor agonists acting on either type A or B receptors. NAD(+) (an essential cofactor of SIRT1) was also increased. GABA augmented SIRT1 enzymatic activity, which resulted in deacetylation of the p65 component of NF-κB, and this is known to interfere with the activation this pathway. GABA increased insulin production and reduced drug-induced apoptosis, and these actions were reversed by SIRT1 inhibitors. We examined whether SIRT1 is similarly induced in newly isolated human islet cells. Indeed, GABA increased both NAD(+) and SIRT1 (but not sirtuins 2, 3 and 6). It protected human islet cells against spontaneous apoptosis in culture, and this was negated by a SIRT1 inhibitor. Thus, our findings suggest that major beneficial effects of GABA on beta cells are due to increased SIRT1 and NAD(+), and point to a new pathway for diabetes therapy.
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Tian J, Dang H, Nguyen AV, Chen Z, Kaufman DL. Combined therapy with GABA and proinsulin/alum acts synergistically to restore long-term normoglycemia by modulating T-cell autoimmunity and promoting β-cell replication in newly diabetic NOD mice. Diabetes 2014; 63:3128-34. [PMID: 25146474 PMCID: PMC4141368 DOI: 10.2337/db13-1385] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Antigen-based therapies (ABTs) fail to restore normoglycemia in newly diabetic NOD mice, perhaps because too few β-cells remain by the time that ABT-induced regulatory responses arise and spread. We hypothesized that combining a fast-acting anti-inflammatory agent with an ABT could limit pathogenic responses while ABT-induced regulatory responses arose and spread. γ-Aminobutyric acid (GABA) administration can inhibit inflammation, enhance regulatory T-cell (Treg) responses, and promote β-cell replication in mice. We examined the effect of combining a prototypic ABT, proinsulin/alum, with GABA treatment in newly diabetic NOD mice. Proinsulin/alum monotherapy failed to correct hyperglycemia, while GABA monotherapy restored normoglycemia for a short period. Combined treatment restored normoglycemia in the long term with apparent permanent remission in some mice. Proinsulin/alum monotherapy induced interleukin (IL)-4- and IL-10-secreting T-cell responses that spread to other β-cell autoantigens. GABA monotherapy induced moderate IL-10 (but not IL-4) responses to β-cell autoantigens. Combined treatment synergistically reduced spontaneous type 1 T-helper cell responses to autoantigens, ABT-induced IL-4 and humoral responses, and insulitis, but enhanced IL-10 and Treg responses and promoted β-cell replication in the islets. Thus, combining ABT with GABA can inhibit pathogenic T-cell responses, induce Treg responses, promote β-cell replication, and effectively restore normoglycemia in newly diabetic NOD mice. Since these treatments appear safe for humans, they hold promise for type 1 diabetes intervention.
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Affiliation(s)
- Jide Tian
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - Hoa Dang
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - An Viet Nguyen
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - Zheying Chen
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - Daniel L Kaufman
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
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Guyon A. CXCL12 chemokine and GABA neurotransmitter systems crosstalk and their putative roles. Front Cell Neurosci 2014; 5:115. [PMID: 24808825 PMCID: PMC4009426 DOI: 10.3389/fncel.2014.00115] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/08/2014] [Indexed: 11/28/2022] Open
Abstract
Since CXCL12 and its receptors, CXCR4 and CXCR7, have been found in the brain, the role of this chemokine has been expanded from chemoattractant in the immune system to neuromodulatory in the brain. Several pieces of evidence suggest that this chemokine system could crosstalk with the GABAergic system, known to be the main inhibitory neurotransmitter system in the brain. Indeed, GABA and CXCL12 as well as their receptors are colocalized in many cell types including neurons and there are several examples in which these two systems interact. Several mechanisms can be proposed to explain how these systems interact, including receptor–receptor interactions, crosstalk at the level of second messenger cascades, or direct pharmacological interactions, as GABA and GABAB receptor agonists/antagonists have been shown to be allosteric modulators of CXCR4. The interplay between CXCL12/CXCR4-CXCR7 and GABA/GABAA-GABAB receptors systems could have many physiological implications in neurotransmission, cancer and inflammation. In addition, the GABAB agonist baclofen is currently used in medicine to treat spasticity in patients with spinal cord injury, cerebral palsy, traumatic brain injury, multiple sclerosis, and other disorders. More recently it has also been used in the treatment of alcohol dependence and withdrawal. The allosteric effects of this agent on CXCR4 could contribute to these beneficial effects or at the opposite, to its side effects.
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Affiliation(s)
- Alice Guyon
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Université Nice Sophia Antipolis Valbonne, France
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Modulation of cytokine production by drugs with antiepileptic or mood stabilizer properties in anti-CD3- and anti-Cd40-stimulated blood in vitro. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:806162. [PMID: 24757498 PMCID: PMC3976773 DOI: 10.1155/2014/806162] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 02/02/2014] [Accepted: 02/07/2014] [Indexed: 01/12/2023]
Abstract
Increased cytokine production possibly due to oxidative stress has repeatedly been shown to play a pivotal role in the pathophysiology of epilepsy and bipolar disorder. Recent in vitro and animal studies of valproic acid (VPA) report antioxidative and anti-inflammatory properties, and suppression of interleukin (IL)-6 and tumor necrosis factor (TNF)-α. We tested the effect of drugs with antiepileptic or mood stabilizer properties, namely, primidone (PRM), carbamazepine (CBZ), levetiracetam (LEV), lamotrigine (LTG), VPA, oxcarbazepine (OXC), topiramate (TPM), phenobarbital (PB), and lithium on the production of the following cytokines in vitro: interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-17, IL-22, and TNF-α. We performed a whole blood assay with stimulated blood of 14 healthy female subjects. Anti-human CD3 monoclonal antibody OKT3, combined with 5C3 antibody against CD40, was used as stimulant. We found a significant reduction of IL-1 and IL-2 levels with all tested drugs other than lithium in the CD3/5C3-stimulated blood; VPA led to a decrease in IL-1β, IL-2, IL-4, IL-6, IL-17, and TNF-α production, which substantiates and adds knowledge to current hypotheses on VPA's anti-inflammatory properties.
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125
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GABA protects human islet cells against the deleterious effects of immunosuppressive drugs and exerts immunoinhibitory effects alone. Transplantation 2013; 96:616-23. [PMID: 23851932 DOI: 10.1097/tp.0b013e31829c24be] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND We recently found that γ-aminobutyric acid (GABA) protects mouse islet β cells. It prevented autoimmune type 1 diabetes in mice, induced islet β-cell regeneration, and exerted immunoinhibitory effects. However, it is not known whether GABA would be equally active on human islet and immune cells. METHODS In vitro culture of human islets and immune cells with or without GABA and immunosuppressive drugs. In vitro analysis of apoptosis, proliferation, nuclear factor (NF)-κB activation, calcium signaling, and insulin secretion. RESULTS GABA reduced human islet cell apoptosis in culture, such that the yield of live cells was approximately tripled after 1 week, and it stimulated insulin secretion. It protected against the deleterious effects of rapamycin, tacrolimus, and mycophenolate mofetil. In human immune cells, GABA had inhibitory effects similar to mouse cells, such as suppressed anti-CD3-stimulated T-cell proliferation, in a GABA type A receptor-dependent fashion. The immunosuppressive mechanisms have been unclear, but we found that GABA blocked calcium influx, which is a key activation signal. GABA also suppressed NF-κB activation in both human islet cells and immune cells. We found that it could be combined with rapamycin to increase its suppressive effects. CONCLUSIONS GABA improved human islet cell survival and had suppressive effects on human immune cells. It inhibited canonical NF-κB activation in both islet and immune cells. This is important because activation of this pathway is detrimental to islet cells and likely promotes damaging autoimmunity and alloreactivity against transplanted islets. These findings suggest that GABA might find applications in clinical islet transplantation.
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Tian J, Dang H, Chen Z, Guan A, Jin Y, Atkinson MA, Kaufman DL. γ-Aminobutyric acid regulates both the survival and replication of human β-cells. Diabetes 2013; 62:3760-5. [PMID: 23995958 PMCID: PMC3806626 DOI: 10.2337/db13-0931] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
γ-Aminobutyric acid (GABA) has been shown to inhibit apoptosis of rodent β-cells in vitro. In this study, we show that activation of GABAA receptors (GABAA-Rs) or GABAB-Rs significantly inhibits oxidative stress-related β-cell apoptosis and preserves pancreatic β-cells in streptozotocin-rendered hyperglycemic mice. Moreover, treatment with GABA, or a GABAA-R- or GABAB-R-specific agonist, inhibited human β-cell apoptosis following islet transplantation into NOD/scid mice. Accordingly, activation of GABAA-Rs and/or GABAB-Rs may be a useful adjunct therapy for human islet transplantation. GABA-R agonists also promoted β-cell replication in hyperglycemic mice. While a number of agents can promote rodent β-cell replication, most fail to provide similar activities with human β-cells. In this study, we show that GABA administration promotes β-cell replication and functional recovery in human islets following implantation into NOD/scid mice. Human β-cell replication was induced by both GABAA-R and GABAB-R activation. Hence, GABA regulates both the survival and replication of human β-cells. These actions, together with the anti-inflammatory properties of GABA, suggest that modulation of peripheral GABA-Rs may represent a promising new therapeutic strategy for improving β-cell survival following human islet transplantation and increasing β-cells in patients with diabetes.
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Affiliation(s)
- Jide Tian
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California
- Corresponding author: Daniel L. Kaufman, , or Jide Tian,
| | - Hoa Dang
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California
| | - Zheying Chen
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California
| | - Alice Guan
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California
| | - Yingli Jin
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California
| | - Mark A. Atkinson
- Departments of Pathology and Pediatrics, University of Florida, Gainesville, Florida
| | - Daniel L. Kaufman
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California
- Corresponding author: Daniel L. Kaufman, , or Jide Tian,
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127
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Affiliation(s)
- Paolo Fiorina
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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128
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Himmerich H, Bartsch S, Hamer H, Mergl R, Schönherr J, Petersein C, Munzer A, Kirkby KC, Bauer K, Sack U. Impact of mood stabilizers and antiepileptic drugs on cytokine production in-vitro. J Psychiatr Res 2013; 47:1751-9. [PMID: 23978396 DOI: 10.1016/j.jpsychires.2013.07.026] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 06/19/2013] [Accepted: 07/26/2013] [Indexed: 12/18/2022]
Abstract
Changes within the immune system have been reported to contribute to the pathophysiology of bipolar disorder and epilepsy. Interestingly, overlapping results regarding the cytokine system have been found for both diseases, namely alterations of interleukins IL-1β, IL-2, IL-4, IL-6, and tumor necrosis factor-α (TNF-α). However, the effect of mood stabilizers and antiepileptic drugs (AEDs) on these cytokines has not been systematically evaluated, and their effect on IL-17 and IL-22, other immunologically important cytokines, has not been reported. Therefore, we systematically measured levels of IL-1β, IL-2, IL-4, IL-6, IL-17, IL-22 and TNF-α in stimulated blood of 14 healthy female subjects in a whole blood assay using the toxic shock syndrome toxin TSST-1 as stimulant. Blood was supplemented with the mood stabilizers or antiepileptic drugs primidone (PRM), carbamazepine (CBZ), levetiracetam (LEV), lamotrigine (LTG), valproic acid (VPA), oxcarbazepine (OXC), topiramate (TPM), phenobarbital (PB), lithium, or no drug. IL-1β production was significantly decreased by PRM, CBZ, LEV, LTG, OXC, PB and lithium. IL-2 significantly decreased by PRM, CBZ, LEV, LTG, VPA, OXC, TPM and PB. IL-22 significantly increased by PRM, CBZ, LEV, OXC, TPM and lithium and decreased by VPA. TNF-α production significantly decreased under all applied drugs. The mechanism of action and side effects of mood stabilizers and AEDs may involve modulation of IL-1β, IL-2, IL-22 and TNF-α signaling pathways. IL-22 may be a research target for specific therapeutic effects of mood stabilizers and AEDs. These drugs might influence cytokine production by modulating ion channels and γ-aminobutyric acid (GABA) receptors of immune cells.
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Affiliation(s)
- Hubertus Himmerich
- Department of Psychiatry, University of Leipzig, Semmelweisstr. 10, 04103 Leipzig, Germany.
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Baclofen and other GABAB receptor agents are allosteric modulators of the CXCL12 chemokine receptor CXCR4. J Neurosci 2013; 33:11643-54. [PMID: 23843532 DOI: 10.1523/jneurosci.6070-11.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
CXCR4, a receptor for the chemokine CXCL12 (stromal-cell derived factor-1α), is a G-protein-coupled receptor (GPCR), expressed in the immune and CNS and integrally involved in various neurological disorders. The GABAB receptor is also a GPCR that mediates metabotropic action of the inhibitory neurotransmitter GABA and is located on neurons and immune cells as well. Using diverse approaches, we report novel interaction between GABAB receptor agents and CXCR4 and demonstrate allosteric binding of these agents to CXCR4. First, both GABAB antagonists and agonists block CXCL12-elicited chemotaxis in human breast cancer cells. Second, a GABAB antagonist blocks the potentiation by CXCL12 of high-threshold Ca(2+) channels in rat neurons. Third, electrophysiology in Xenopus oocytes and human embryonic kidney cell line 293 cells in which we coexpressed rat CXCR4 and the G-protein inward rectifier K(+) (GIRK) channel showed that GABAB antagonist and agonist modified CXCL12-evoked activation of GIRK channels. To investigate whether GABAB ligands bind to CXCR4, we expressed this receptor in heterologous systems lacking GABAB receptors and performed competition binding experiments. Our fluorescent resonance energy transfer experiments suggest that GABAB ligands do not bind CXCR4 at the CXCL12 binding pocket suggesting allosteric modulation, in accordance with our electrophysiology experiments. Finally, using backscattering interferometry and lipoparticles containing only the CXCR4 receptor, we quantified the binding affinity for the GABAB ligands, confirming a direct interaction with the CXCR4 receptor. The effect of GABAergic agents on CXCR4 suggests new therapeutic potentials for neurological and immune diseases.
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Yang Y, Luo H, Cheng LX, Liu K. Inhibitory role for GABA in atherosclerosis. Med Hypotheses 2013; 81:803-4. [PMID: 24075593 DOI: 10.1016/j.mehy.2013.08.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 08/14/2013] [Accepted: 08/28/2013] [Indexed: 11/17/2022]
Abstract
γ-Aminobutyric acid (GABA), the classical inhibitory neurotransmitter in the nervous system, has a parallel inhibitory role in the immune system. It affects a variety of functional properties of the immune cells like monocyte migration, macrophage cholesterol efflux, regulatory T cell proliferation and inflammatory cytokine secretion. All of these are the main pathologic processes of atherosclerosis, a chronic inflammatory disease involving both innate and adaptive immune responses in the artery wall. Moreover, GABA has neuroprotective effects in brain ischemic injury, which is one of the serious complications of atherosclerosis. Therefore, we hypothesize GABA may be a prospect immune cell targeting therapy in atherosclerosis.
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Affiliation(s)
- Ying Yang
- Department of Cardiology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
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Benzodiazepine augmented γ-amino-butyric acid signaling increases mortality from pneumonia in mice. Crit Care Med 2013; 41:1627-36. [PMID: 23478657 DOI: 10.1097/ccm.0b013e31827c0c8d] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Benzodiazepines are used for treating anxiety, epilepsy, muscle spasm, alcohol withdrawal, palliation, insomnia, and sedation as they allosterically modulate γ-amino-butyric acid type A (GABAA) receptors. Despite widespread use, the importance and mechanism of their immune side-effects are poorly understood. Herein we sought to elucidate the impact and mechanism of benzodiazepine-induced susceptibility to infection at anxiolytic doses in mice. DESIGN Animal randomized controlled trial. SETTING Laboratory. SUBJECTS Adult female C57BL/6 and BALB/c mice. INTERVENTIONS The effect of a subsedative, anxiolytic dose of diazepam (2 mg kg intraperitoneal) was investigated in a murine Streptococcus pneumoniae pneumonia model. MEASUREMENT AND MAIN RESULTS Mortality, bacterial and cytokine load, cell recruitment, and intracellular pH were measured. Diazepam treatment did not affect immune homeostasis in the lung. However, diazepam increased mortality and bacterial load from S. pneumoniae pneumonia. The increases in mortality and bacterial load were reversed by a GABAA antagonist, bicuculline, indicating dependence on GABAA receptor signaling. While cell recruitment was unaltered by diazepam, the cytokine response to infection was affected, suggesting that local responses to the pathogen were perturbed. Macrophage and monocytes expressed benzodiazepine sensitive (α1-γ2) GABAA receptors. Interestingly macrophage GABAA receptor expression was regulated by bacterial toll-like receptor agonists and cytokines indicating an endogenous role in the immune response. Functionally diazepam appeared to counteract the endogenous down-regulation of GABAA signaling during infection. Consistent with augmented GABAA signaling, diazepam provoked intracellular acidosis in macrophage, leading to impaired cytokine production, bacterial phagocytosis and killing. In contrast, selective benzodiazepines that do not target the α1 GABAA subunit did not affect macrophage function ex vivo or increase susceptibility to pneumonia in vivo. CONCLUSIONS Our data highlight the regulation of macrophage function by GABAA receptor signaling and the potential harm of benzodiazepine exposure during pneumonia. Therapeutically, selective drugs may improve the safety profile of benzodiazepines.
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Saligrama N, Case LK, del Rio R, Noubade R, Teuscher C. Systemic lack of canonical histamine receptor signaling results in increased resistance to autoimmune encephalomyelitis. THE JOURNAL OF IMMUNOLOGY 2013; 191:614-22. [PMID: 23772030 DOI: 10.4049/jimmunol.1203137] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Histamine (HA) is a key regulator of experimental allergic encephalomyelitis (EAE), the autoimmune model of multiple sclerosis. HA exerts its effects through four known G-protein-coupled receptors: H1, H2, H3, and H4 (histamine receptors; H(1-4)R). Using HR-deficient mice, our laboratory has demonstrated that H1R, H2R, H3R, and H4R play important roles in EAE pathogenesis, by regulating encephalitogenic T cell responses, cytokine production by APCs, blood-brain barrier permeability, and T regulatory cell activity, respectively. Histidine decarboxylase-deficient mice (HDCKO), which lack systemic HA, exhibit more severe EAE and increased Th1 effector cytokine production by splenocytes in response to myelin oligodendrocyte gp35-55. In an inverse approach, we tested the effect of depleting systemic canonical HA signaling on susceptibility to EAE by generating mice lacking all four known G-protein-coupled-HRs (H(1-4)RKO mice). In this article, we report that in contrast to HDCKO mice, H(1-4)RKO mice develop less severe EAE compared with wild-type animals. Furthermore, splenocytes from immunized H(1-4)RKO mice, compared with wild-type mice, produce a lower amount of Th1/Th17 effector cytokines. The opposing results seen between HDCKO and H1-4RKO mice suggest that HA may signal independently of H1-4R and support the existence of an alternative HAergic pathway in regulating EAE resistance. Understanding and exploiting this pathway has the potential to lead to new disease-modifying therapies in multiple sclerosis and other autoimmune and allergic diseases.
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Affiliation(s)
- Naresha Saligrama
- Department of Medicine, University of Vermont, Burlington, VT 05405, USA
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Systemic treatment with the inhibitory neurotransmitter γ-aminobutyric acid aggravates experimental autoimmune encephalomyelitis by affecting proinflammatory immune responses. J Neuroimmunol 2012. [PMID: 23194644 DOI: 10.1016/j.jneuroim.2012.11.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transcriptomic and proteomic analyses of multiple sclerosis (MS) lesions indicate alterations in the gamma-aminobutyric acid (GABA) inhibitory system, suggesting its involvement in the disease process. To further elucidate the role of GABA in central nervous system (CNS) inflammation in vivo, the chronic myelin oligodendrocyte glycoprotein (MOG)(35-55) experimental autoimmune encephalomyelitis (EAE) model was used. Daily GABA injections (200mg/kg) from day 3 onwards significantly augmented disease severity, which was associated with increased CNS mRNA expression levels of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-6. GABA-treated mice showed enhanced MOG-dependent proliferation and were skewed towards a T helper 1 phenotype. Moreover, in vitro, the lipopolysaccharide (LPS)-induced increase in interleukin (IL)-6 production by macrophages was enhanced at low GABA concentrations (0.03-0.3mM). In sharp contrast to exogenous GABA administration, endogenous GABA increment by systemic treatment with the GABA-transaminase inhibitor vigabatrin (250mg/kg) had prophylactic as well as therapeutic potential in EAE. Together, these results indicate an immune amplifying role of GABA in neuroinflammatory diseases like MS.
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Mendu SK, Bhandage A, Jin Z, Birnir B. Different subtypes of GABA-A receptors are expressed in human, mouse and rat T lymphocytes. PLoS One 2012; 7:e42959. [PMID: 22927941 PMCID: PMC3424250 DOI: 10.1371/journal.pone.0042959] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 07/16/2012] [Indexed: 11/19/2022] Open
Abstract
γ-aminobutyric acid (GABA) is the most prominent neuroinhibitory transmitter in the brain, where it activates neuronal GABA-A receptors (GABA-A channels) located at synapses and outside of synapses. The GABA-A receptors are primary targets of many clinically useful drugs. In recent years, GABA has been shown to act as an immunomodulatory molecule. We have examined in human, mouse and rat CD4+ and CD8+ T cells which subunit isoforms of the GABA-A channels are expressed. The channel physiology and drug specificity is dictated by the GABA-A receptor subtype, which in turn is determined by the subunit isoforms that make the channel. There were 5, 8 and 13 different GABA-A subunit isoforms identified in human, mouse and rat CD4+ and CD8+ T cells, respectively. Importantly, the γ2 subunit that imposes benzodiazepine sensitivity on the GABA-A receptors, was only detected in the mouse T cells. Immunoblots and immunocytochemistry showed abundant GABA-A channel proteins in the T cells from all three species. GABA-activated whole-cell transient and tonic currents were recorded. The currents were inhibited by picrotoxin, SR95531 and bicuculline, antagonists of GABA-A channels. Clearly, in both humans and rodents T cells, functional GABA-A channels are expressed but the subtypes vary. It is important to bear in mind the interspecies difference when selecting the appropriate animal models to study the physiological role and pharmacological properties of GABA-A channels in CD4+ and CD8+ T cells and when selecting drugs aimed at modulating the human T cells function.
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Affiliation(s)
| | | | | | - Bryndis Birnir
- Molecular Physiology and Neuroscience, Department of Neuroscience, Uppsala University, Uppsala, Sweden
- * E-mail:
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135
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Feske S, Skolnik EY, Prakriya M. Ion channels and transporters in lymphocyte function and immunity. Nat Rev Immunol 2012; 12:532-47. [PMID: 22699833 DOI: 10.1038/nri3233] [Citation(s) in RCA: 334] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Lymphocyte function is regulated by a network of ion channels and transporters in the plasma membrane of B and T cells. These proteins modulate the cytoplasmic concentrations of diverse cations, such as calcium, magnesium and zinc ions, which function as second messengers to regulate crucial lymphocyte effector functions, including cytokine production, differentiation and cytotoxicity. The repertoire of ion-conducting proteins includes calcium release-activated calcium (CRAC) channels, P2X receptors, transient receptor potential (TRP) channels, potassium channels, chloride channels and magnesium and zinc transporters. This Review discusses the roles of ion conduction pathways in lymphocyte function and immunity.
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Affiliation(s)
- Stefan Feske
- Department of Pathology, New York University Langone Medical Center, New York, New York 10016, USA.
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136
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Kotani H, Tanabe H, Mizukami H, Amagaya S, Inoue M. A Naturally Occurring Rexinoid, Honokiol, Can Serve as a Regulator of Various Retinoid X Receptor Heterodimers. Biol Pharm Bull 2012; 35:1-9. [DOI: 10.1248/bpb.35.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hitoshi Kotani
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University
- Laboratory of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hiroki Tanabe
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University
| | - Hajime Mizukami
- Laboratory of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Sakae Amagaya
- Department of Kampo Pharmaceutical Sciences, Nihon Pharmaceutical University
| | - Makoto Inoue
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University
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137
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Jin Z, Mendu SK, Birnir B. GABA is an effective immunomodulatory molecule. Amino Acids 2011; 45:87-94. [PMID: 22160261 PMCID: PMC3680704 DOI: 10.1007/s00726-011-1193-7] [Citation(s) in RCA: 182] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 11/30/2011] [Indexed: 12/13/2022]
Abstract
In recent years, it has become clear that there is an extensive cross-talk between the nervous and the immune system. Somewhat surprisingly, the immune cells themselves do express components of the neuronal neurotransmitters systems. What role the neurotransmitters, their ion channels, receptors and transporters have in immune function and regulation is an emerging field of study. Several recent studies have shown that the immune system is capable of synthesizing and releasing the classical neurotransmitter GABA (γ-aminobutyric acid). GABA has a number of effects on the immune cells such as activation or suppression of cytokine secretion, modification of cell proliferation and GABA can even affect migration of the cells. The immune cells encounter GABA when released by the immune cells themselves or when the immune cells enter the brain. In addition, GABA can also be found in tissues like the lymph nodes, the islets of Langerhans and GABA is in high enough concentration in blood to activate, e.g., GABA-A channels. GABA appears to have a role in autoimmune diseases like multiple sclerosis, type 1 diabetes, and rheumatoid arthritis and may modulate the immune response to infections. In the near future, it will be important to work out what specific effects GABA has on the function of the different types of immune cells and determine the underlying mechanisms. In this review, we discuss some of the recent findings revealing the role of GABA as an immunomodulator.
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Affiliation(s)
- Zhe Jin
- Department of Neuroscience, Molecular Physiology and Neuroscience, Uppsala University, BMC, BOX 593, 75124 Uppsala, Sweden
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138
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Bibolini M, Chanaday N, Báez N, Degano A, Monferran C, Roth G. Inhibitory role of diazepam on autoimmune inflammation in rats with experimental autoimmune encephalomyelitis. Neuroscience 2011; 199:421-8. [DOI: 10.1016/j.neuroscience.2011.08.076] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 08/18/2011] [Accepted: 08/31/2011] [Indexed: 11/25/2022]
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139
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Sternberg Z, Cesario A, Rittenhouse-Olson K, Sobel RA, Leung YK, Pankewycz O, Zhu B, Whitcomb T, Sternberg DS, Munschauer FE. Acamprosate modulates experimental autoimmune encephalomyelitis. Inflammopharmacology 2011; 20:39-48. [PMID: 22090150 DOI: 10.1007/s10787-011-0097-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 09/24/2011] [Indexed: 10/15/2022]
Abstract
OBJECTIVE This pilot study aimed to determine the efficacy of acamprosate (N-acetyl homotaurine) in reducing the pathological features of experimental autoimmune encephalomyelitis (EAE) which is an animal model for multiple sclerosis (MS). BACKGROUND The amino acid taurine has multiple biological activities including immunomodulation and neuromodulation. The synthetic acetylated taurine derivative, acamprosate, which crosses the blood-brain barrier more readily compared to taurine, is currently being used for the prevention of alcohol withdrawal symptoms associated with enhanced glutamatergic receptor function and GABA receptor hypofunction. METHODS EAE was induced in C57BL/6 female mice with myelin oligodendrocyte glyocoprotein, amino acid 35-55. Mice were treated with 20, 100 and 500 mg/kg acamprosate for 21 days. RESULTS Neurological scores at disease peak were reduced by 21, 64 and 9% in the 20, 100 and 500 mg/kg groups, respectively. Neurological improvement in the 100 mg/kg group correlated with a reduction in numbers of inflammatory lesions and the extent of CNS demyelination. Blood TNF-α levels were significantly reduced in the 500 mg/kg group. DISCUSSION Acamprosate and other taurine analogs have a potential for future MS therapy.
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Affiliation(s)
- Z Sternberg
- Department of Neurology, Baird MS Center, Jacobs Neurological Institute, 100 High Street, Buffalo, NY 14203, USA.
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140
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Sidorkiewicz M, Brocka M, Bronis M, Grek M, Jozwiak B, Piekarska A, Bartkowiak J. The altered expression of α1 and β3 subunits of the gamma-aminobutyric acid A receptor is related to the hepatitis C virus infection. Eur J Clin Microbiol Infect Dis 2011; 31:1537-42. [PMID: 22080424 PMCID: PMC3364423 DOI: 10.1007/s10096-011-1475-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/20/2011] [Indexed: 01/02/2023]
Abstract
The modulation of the gamma-aminobutyric acid type A (GABA A) receptors activity was observed in several chronic hepatitis failures, including hepatitis C. The expression of GABA A receptor subunits α1 and β3 was detected in peripheral blood mononuclear cells (PBMCs) originated from healthy donors. The aim of the study was to evaluate if GABA A α1 and β3 expression can also be observed in PBMCs from chronic hepatitis C (CHC) patients and to evaluate a possible association between their expression and the course of hepatitis C virus (HCV) infection. GABA A α1- and β3-specific mRNAs presence and a protein expression in PBMCs from healthy donors and CHC patients were screened by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. In patients, HCV RNA was determined in sera and PBMCs. It was shown that GABA A α1 and β3 expression was significantly different in PBMCs from CHC patients and healthy donors. In comparison to healthy donors, CHC patients were found to present an increase in the expression of GABA A α1 subunit and a decrease in the expression of β3 subunit in their PBMCs. The modulation of α1 and β3 GABA A receptors subunits expression in PBMCs may be associated with ongoing or past HCV infection.
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Affiliation(s)
- M Sidorkiewicz
- Department of Medical Biochemistry, Medical University of Łódź, Łódź, Poland.
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141
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Oral treatment with γ-aminobutyric acid improves glucose tolerance and insulin sensitivity by inhibiting inflammation in high fat diet-fed mice. PLoS One 2011; 6:e25338. [PMID: 21966503 PMCID: PMC3178643 DOI: 10.1371/journal.pone.0025338] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 09/01/2011] [Indexed: 01/14/2023] Open
Abstract
Adipocyte and β-cell dysfunction and macrophage-related chronic inflammation are critical for the development of obesity-related insulin resistance and type 2 diabetes mellitus (T2DM), which can be negatively regulated by Tregs. Our previous studies and those of others have shown that activation of γ-aminobutyric acid (GABA) receptors inhibits inflammation in mice. However, whether GABA could modulate high fat diet (HFD)-induced obesity, glucose intolerance and insulin resistance has not been explored. Here, we show that although oral treatment with GABA does not affect water and food consumption it inhibits the HFD-induced gain in body weights in C57BL/6 mice. Furthermore, oral treatment with GABA significantly reduced the concentrations of fasting blood glucose, and improved glucose tolerance and insulin sensitivity in the HFD-fed mice. More importantly, after the onset of obesity and T2DM, oral treatment with GABA inhibited the continual HFD-induced gain in body weights, reduced the concentrations of fasting blood glucose and improved glucose tolerance and insulin sensitivity in mice. In addition, oral treatment with GABA reduced the epididymal fat mass, adipocyte size, and the frequency of macrophage infiltrates in the adipose tissues of HFD-fed mice. Notably, oral treatment with GABA significantly increased the frequency of CD4(+)Foxp3(+) Tregs in mice. Collectively, our data indicated that activation of peripheral GABA receptors inhibited the HFD-induced glucose intolerance, insulin resistance, and obesity by inhibiting obesity-related inflammation and up-regulating Treg responses in vivo. Given that GABA is safe for human consumption, activators of GABA receptors may be valuable for the prevention of obesity and intervention of T2DM in the clinic.
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142
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Tian J, Dang H, Kaufman DL. Combining antigen-based therapy with GABA treatment synergistically prolongs survival of transplanted ß-cells in diabetic NOD mice. PLoS One 2011; 6:e25337. [PMID: 21966502 PMCID: PMC3178649 DOI: 10.1371/journal.pone.0025337] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 09/01/2011] [Indexed: 01/13/2023] Open
Abstract
Antigen-based therapies (ABTs) very effectively prevent the development of type 1 diabetes (T1D) when given to young nonobese diabetic (NOD) mice, however, they have little or no ability to reverse hyperglycemia in newly diabetic NOD mice. More importantly, ABTs have not yet demonstrated an ability to effectively preserve residual ß-cells in individuals newly diagnosed with type 1 diabetes (T1D). Accordingly, there is great interest in identifying new treatments that can be combined with ABTs to safely protect ß-cells in diabetic animals. The activation of γ-aminobutyric acid (GABA) receptors (GABA-Rs) on immune cells has been shown to prevent T1D, experimental autoimmune encephalomyelitis (EAE) and rheumatoid arthritis in mouse models. Based on GABA's ability to inhibit different autoimmune diseases and its safety profile, we tested whether the combination of ABT with GABA treatment could prolong the survival of transplanted ß-cells in newly diabetic NOD mice. Newly diabetic NOD mice were untreated, or given GAD/alum (20 or 100 µg) and placed on plain drinking water, or water containing GABA (2 or 6 mg/ml). Twenty-eight days later, they received syngenic pancreas grafts and were monitored for the recurrence of hyperglycemia. Hyperglycemia reoccurred in the recipients given plain water, GAD monotherapy, GABA monotherapy, GAD (20 µg)+GABA (2 mg/ml), GAD (20 µg)+GABA (6 mg/ml) and GAD (100 µg)+GABA (6 mg/ml) about 1, 2-3, 3, 2-3, 3-8 and 10-11 weeks post-transplantation, respectively. Thus, combined GABA and ABT treatment had a synergistic effect in a dose-dependent fashion. These findings suggest that co-treatment with GABA (or other GABA-R agonists) may provide a new strategy to safely enhance the efficacy of other therapeutics designed to prevent or reverse T1D, as well as other T cell-mediated autoimmune diseases.
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Affiliation(s)
- Jide Tian
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Hoa Dang
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Daniel L. Kaufman
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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143
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GABA exerts protective and regenerative effects on islet beta cells and reverses diabetes. Proc Natl Acad Sci U S A 2011; 108:11692-7. [PMID: 21709230 DOI: 10.1073/pnas.1102715108] [Citation(s) in RCA: 266] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Type 1 diabetes (T1D) is an autoimmune disease characterized by insulitis and islet β-cell loss. Thus, an effective therapy may require β-cell restoration and immune suppression. Currently, there is no treatment that can achieve both goals efficiently. We report here that GABA exerts antidiabetic effects by acting on both the islet β-cells and immune system. Unlike in adult brain or islet α-cells in which GABA exerts hyperpolarizing effects, in islet β-cells, GABA produces membrane depolarization and Ca(2+) influx, leading to the activation of PI3-K/Akt-dependent growth and survival pathways. This provides a potential mechanism underlying our in vivo findings that GABA therapy preserves β-cell mass and prevents the development of T1D. Remarkably, in severely diabetic mice, GABA restores β-cell mass and reverses the disease. Furthermore, GABA suppresses insulitis and systemic inflammatory cytokine production. The β-cell regenerative and immunoinhibitory effects of GABA provide insights into the role of GABA in regulating islet cell function and glucose homeostasis, which may find clinical application.
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144
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Tian J, Yong J, Dang H, Kaufman DL. Oral GABA treatment downregulates inflammatory responses in a mouse model of rheumatoid arthritis. Autoimmunity 2011; 44:465-70. [PMID: 21604972 DOI: 10.3109/08916934.2011.571223] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Current treatments for rheumatoid arthritis (RA) have long-term side effects such that new treatments are needed that can safely help manage the disease. There is a growing appreciation that GABA receptors (GABA-Rs) on immune cells provide new targets that can be used to modulate immune cell activity. Here, we show for the first time that activation of peripheral GABA-Rs can inhibit the development of disease in the collagen-induced arthritis (CIA) mouse model of RA. Mice that received oral GABA had a reduced incidence of CIA, and those mice that did develop CIA had milder symptoms. T cells from GABA-treated mice displayed reduced proliferative responses to collagen and their APC had a reduced ability to promote the proliferation of collagen-reactive T cells. Thus, GABA downregulated both T-cell autoimmunity and APC activity. Collagen-reactive T cells from GABA-treated mice displayed reduced recall responses in the presence of GABA ex vivo, indicating that GABA consumption did not desensitize these cells to GABA. GABA-treated mice had reduced collagen-reactive IgG2a, but not IgG1 antibodies, consistent with reduced Th1 help. The levels of serum anti-collagen IgG2a antibodies were correlated significantly with the CIA disease scores of individual mice. Our results suggest that activation of peripheral GABA-Rs may provide a new modality to modulate T cell, B cell, and APC activity and help ameliorate RA and other inflammatory diseases.
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Affiliation(s)
- Jide Tian
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095-1735, USA
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145
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Wheeler DW, Thompson AJ, Corletto F, Reckless J, Loke JCT, Lapaque N, Grant AJ, Mastroeni P, Grainger DJ, Padgett CL, O'Brien JA, Miller NGA, Trowsdale J, Lummis SCR, Menon DK, Beech JS. Anaesthetic impairment of immune function is mediated via GABA(A) receptors. PLoS One 2011; 6:e17152. [PMID: 21390329 PMCID: PMC3044756 DOI: 10.1371/journal.pone.0017152] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 01/20/2011] [Indexed: 11/19/2022] Open
Abstract
Background GABAA receptors are members of the Cys-loop family of neurotransmitter receptors, proteins which are responsible for fast synaptic transmission, and are the site of action of wide range of drugs [1]. Recent work has shown that Cys-loop receptors are present on immune cells, but their physiological roles and the effects of drugs that modify their function in the innate immune system are currently unclear [2]. We are interested in how and why anaesthetics increase infections in intensive care patients; a serious problem as more than 50% of patients with severe sepsis will die [3]–[6]. As many anaesthetics act via GABAA receptors [7], the aim of this study was to determine if these receptors are present on immune cells, and could play a role in immunocompromising patients. Principal Findings We demonstrate, using RT-PCR, that monocytes express GABAA receptors constructed of α1, α4, β2, γ1 and/or δ subunits. Whole cell patch clamp electrophysiological studies show that GABA can activate these receptors, resulting in the opening of a chloride-selective channel; activation is inhibited by the GABAA receptor antagonists bicuculline and picrotoxin, but not enhanced by the positive modulator diazepam. The anaesthetic drugs propofol and thiopental, which can act via GABAA receptors, impaired monocyte function in classic immunological chemotaxis and phagocytosis assays, an effect reversed by bicuculline and picrotoxin. Significance Our results show that functional GABAA receptors are present on monocytes with properties similar to CNS GABAA receptors. The functional data provide a possible explanation as to why chronic propofol and thiopental administration can increase the risk of infection in critically ill patients: their action on GABAA receptors inhibits normal monocyte behaviour. The data also suggest a potential solution: monocyte GABAA receptors are insensitive to diazepam, thus the use of benzodiazepines as an alternative anesthetising agent may be advantageous where infection is a life threatening problem.
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Affiliation(s)
- Daniel W. Wheeler
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Andrew J. Thompson
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Federico Corletto
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Jill Reckless
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Justin C. T. Loke
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Nicolas Lapaque
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Andrew J. Grant
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Pietro Mastroeni
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - David J. Grainger
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Claire L. Padgett
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - John A. O'Brien
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Nigel G. A. Miller
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - John Trowsdale
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Sarah C. R. Lummis
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
- * E-mail:
| | - David K. Menon
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - John S. Beech
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
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146
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Wheeler DW, Thompson AJ, Corletto F, Reckless J, Loke JCT, Lapaque N, Grant AJ, Mastroeni P, Grainger DJ, Padgett CL, O'Brien JA, Miller NGA, Trowsdale J, Lummis SCR, Menon DK, Beech JS. Anaesthetic impairment of immune function is mediated via GABA(A) receptors. PLoS One 2011. [PMID: 21390329 DOI: 10.1371/journal.pone.0017152.g001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND GABA(A) receptors are members of the Cys-loop family of neurotransmitter receptors, proteins which are responsible for fast synaptic transmission, and are the site of action of wide range of drugs. Recent work has shown that Cys-loop receptors are present on immune cells, but their physiological roles and the effects of drugs that modify their function in the innate immune system are currently unclear. We are interested in how and why anaesthetics increase infections in intensive care patients; a serious problem as more than 50% of patients with severe sepsis will die. As many anaesthetics act via GABA(A) receptors, the aim of this study was to determine if these receptors are present on immune cells, and could play a role in immunocompromising patients. PRINCIPAL FINDINGS We demonstrate, using RT-PCR, that monocytes express GABA(A) receptors constructed of α1, α4, β2, γ1 and/or δ subunits. Whole cell patch clamp electrophysiological studies show that GABA can activate these receptors, resulting in the opening of a chloride-selective channel; activation is inhibited by the GABA(A) receptor antagonists bicuculline and picrotoxin, but not enhanced by the positive modulator diazepam. The anaesthetic drugs propofol and thiopental, which can act via GABA(A) receptors, impaired monocyte function in classic immunological chemotaxis and phagocytosis assays, an effect reversed by bicuculline and picrotoxin. SIGNIFICANCE Our results show that functional GABA(A) receptors are present on monocytes with properties similar to CNS GABA(A) receptors. The functional data provide a possible explanation as to why chronic propofol and thiopental administration can increase the risk of infection in critically ill patients: their action on GABA(A) receptors inhibits normal monocyte behaviour. The data also suggest a potential solution: monocyte GABA(A) receptors are insensitive to diazepam, thus the use of benzodiazepines as an alternative anesthetising agent may be advantageous where infection is a life threatening problem.
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Affiliation(s)
- Daniel W Wheeler
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
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147
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Tian Y, Gunther JR, Liao IH, Liu D, Ander BP, Stamova BS, Lit L, Jickling GC, Xu H, Zhan X, Sharp FR. GABA- and acetylcholine-related gene expression in blood correlate with tic severity and microarray evidence for alternative splicing in Tourette syndrome: a pilot study. Brain Res 2011; 1381:228-36. [PMID: 21241679 DOI: 10.1016/j.brainres.2011.01.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 12/08/2010] [Accepted: 01/10/2011] [Indexed: 10/18/2022]
Abstract
Tourette syndrome (TS) is a complex childhood neurodevelopmental disorder characterized by motor and vocal tics. Recently, altered numbers of GABAergic-parvalbumin (PV) and cholinergic interneurons were observed in the basal ganglia of individuals with TS. Thus, we postulated that gamma-amino butyric acid (GABA)- and acetylcholine (ACh)-related genes might be associated with the pathophysiology of TS. Total RNA isolated from whole blood of 26 un-medicated TS subjects and 23 healthy controls (HC) was processed on Affymetrix Human Exon 1.0 ST arrays. Data were analyzed to identify genes whose expression correlated with tic severity in TS, and to identify genes differentially spliced in TS compared to HC subjects. Many genes (3627) correlated with tic severity in TS (p < 0.05) among which GABA- (p = 2.1 × 10⁻³) and ACh- (p = 4.25 × 10⁻⁸) related genes were significantly over-represented. Moreover, several GABA and ACh-related genes were predicted to be alternatively spliced in TS compared to HC including GABA receptors GABRA4 and GABRG1, the nicotinic ACh receptor CHRNA4 and cholinergic differentiation factor (CDF). This pilot study suggests that at least some of these GABA- and ACh-related genes observed in blood that correlate with tics or are alternatively spliced are involved in the pathophysiology of TS and tics.
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Affiliation(s)
- Yingfang Tian
- University of California at Davis, M.I.N.D., Institute and Department of Neurology, USA
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148
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Tian Y, Liao IH, Zhan X, Gunther JR, Ander BP, Liu D, Lit L, Jickling GC, Corbett BA, Bos-Veneman NGP, Hoekstra PJ, Sharp FR. Exon expression and alternatively spliced genes in Tourette Syndrome. Am J Med Genet B Neuropsychiatr Genet 2011; 156B:72-8. [PMID: 21184586 PMCID: PMC3070201 DOI: 10.1002/ajmg.b.31140] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 10/07/2010] [Indexed: 11/08/2022]
Abstract
Tourette Syndrome (TS) is diagnosed based upon clinical criteria including motor and vocal tics. We hypothesized that differences in exon expression and splicing might be useful for pathophysiology and diagnosis. To demonstrate exon expression and alternatively spliced gene differences in blood of individuals with TS compared to healthy controls (HC), RNA was isolated from the blood of 26 un-medicated TS subjects and 23 HC. Each sample was run on Affymetrix Human Exon 1.0 ST (HuExon) arrays and on 3' biased U133 Plus 2.0 (HuU133) arrays. To investigate the differentially expressed exons and transcripts, analyses of covariance (ANCOVA) were performed, controlling for age, gender, and batch. Differential alternative splicing patterns between TS and HC were identified using analyses of variance (ANOVA) models in Partek. Three hundred and seventy-six exon probe sets were differentially expressed between TS and HC (raw P < 0.005, fold change >|1.2|) that separated TS and HC subjects using hierarchical clustering and Principal Components Analysis. The probe sets predicted TS compared to HC with a >90% sensitivity and specificity using a 10-fold cross-validation. Ninety genes (transcripts) had differential expression of a single exon (raw P < 0.005) and were predicted to be alternatively spliced (raw P < 0.05) in TS compared to HC. These preliminary findings might provide insight into the pathophysiology of TS and potentially provide prognostic and diagnostic biomarkers. However, the findings are tempered by the small sample size and multiple comparisons and require confirmation using PCR or deep RNA sequencing and a much larger patient population.
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Affiliation(s)
- Yingfang Tian
- M.I.N.D. Institute, Department of Neurology, University of California at Davis, Sacramento, 95817, USA.
| | - Isaac H. Liao
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
| | - Xinhua Zhan
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
| | - Joan R. Gunther
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
| | - Bradley P. Ander
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
| | - Dazhi Liu
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
| | - Lisa Lit
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
| | - Glen C. Jickling
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
| | - Blythe A. Corbett
- M.I.N.D. Institute and Department of Psychiatry, University of California at Davis, Sacramento, California. USA
| | - Netty GP. Bos-Veneman
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Netherlands
| | - Pieter J. Hoekstra
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Netherlands
| | - Frank R. Sharp
- M.I.N.D. Institute and Department of Neurology, University of California at Davis, Sacramento, California. USA
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149
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Mendu SK, Akesson L, Jin Z, Edlund A, Cilio C, Lernmark A, Birnir B. Increased GABA(A) channel subunits expression in CD8(+) but not in CD4(+) T cells in BB rats developing diabetes compared to their congenic littermates. Mol Immunol 2010; 48:399-407. [PMID: 21112637 DOI: 10.1016/j.molimm.2010.08.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/04/2010] [Accepted: 08/09/2010] [Indexed: 11/30/2022]
Abstract
GABA (γ-aminobutyric acid), the main inhibitory neurotransmitter in the central nervous system is also present in the pancreatic islet β cells where it may function as a paracrine molecule and perhaps as an immunomodulator of lymphocytes infiltrating the pancreatic islet. We examined CD4(+) and CD8(+) T cells from diabetes prone (DR(lyp/lyp)) or resistant (DR(+/+)) congenic biobreeding (BB) rats for expression of GABA(A) channels. Our results show that BB rat CD4(+) and CD8(+) T cells express α1, α2, α3, α4, α6, β3, γ1, δ, ρ1 and ρ2 GABA(A) channel subunits. In CD8(+) T cells from DR(lyp/lyp) animals the subunits were significantly upregulated relative to expression levels in the CD8(+) T cells from DR(+/+) rats as well as from CD4(+) T cells from both DR(lyp/lyp) and DR(+/+) rats. Functional channels were formed in the T cells and physiological concentrations of GABA (100 nM) decreased T cell proliferation. Our results are consistent with the hypothesis that GABA in the islets of Langerhans may diminish inflammation by inhibition of activated T lymphocytes.
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150
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Dionisio L, José De Rosa M, Bouzat C, Esandi MDC. An intrinsic GABAergic system in human lymphocytes. Neuropharmacology 2010; 60:513-9. [PMID: 21093461 DOI: 10.1016/j.neuropharm.2010.11.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 11/01/2010] [Accepted: 11/10/2010] [Indexed: 10/18/2022]
Abstract
γ-amino butyric acid (GABA) is an ubiquitous neurotransmitter in the central nervous system and it is also present in non-neuronal cells. In this study we investigated the presence of neuronal components of the GABAergic system in lymphocytes and its functional significance. By using RT-PCR we detected mRNA expression of different components of the GABAergic system in resting and mitogen-activated lymphocytes: i) GAD67, an isoform of the enzyme that synthetizes GABA; ii) VIAAT, the vesicular protein involved in GABA storage; iii) GABA transporters (GAT-1 and GAT-2); iv) GABA-T, the enzyme that catabolizes GABA; and v) subunits that conform ionotropic GABA receptors. The presence of VIAAT protein in resting and activated cells was confirmed by immunocytochemistry. The functionality of GABA transporters was evaluated by measuring the uptake of radioactive GABA. The results show that [(3)H]GABA uptake is 5-fold higher in activated than in resting lymphocytes. To determine if GABA subunits assemble into functional channels, we performed whole-cell recordings in activated lymphocytes. GABA and muscimol, a specific agonist of ionotropic GABA receptors, elicit macroscopic currents in about 10-15% of the cells. Finally, by using [(3)H]thymidine incorporation assays, we determined that the presence of agonists of GABA receptor during activation inhibits lymphocyte proliferation. Our results reveal that lymphocytes have a functional GABAergic system, similar to the neuronal one, which may operate as a modulator of T-cell activation. Pharmacological modulation of this system may provide new approaches for regulation of T-cell response.
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Affiliation(s)
- Leonardo Dionisio
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, UNS-CONICET, Camino La, Carrindanga Km 7, B8000FWB Bahía Blanca, Argentina
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