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Chen J, Luo Y, Liang X, Kong X, Xiao Q, Tang J, Qi Y, Tang Y, Xiu Y. Alteration in NMDAR subunits in different brain regions of chronic unpredictable mild stress (CUMS) rat model. Transl Neurosci 2022; 13:379-389. [PMID: 36348956 PMCID: PMC9601380 DOI: 10.1515/tnsci-2022-0255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/08/2022] [Accepted: 10/10/2022] [Indexed: 12/12/2022] Open
Abstract
N-Methyl-d-aspartate receptor (NMDAR) signaling pathway has been implicated in the pathogenesis and treatment of depression. However, the role of NMDAR subunits in depression is still unclear. In this study, alteration in all seven NMDAR subunits in several brain areas of rats exposed to chronic unpredictable mild stress (CUMS), an animal model of depression, was detected. Our findings demonstrated that: (1) CUMS could induce a reduction in sucrose preference, an indicator of typical depression-like behaviors; (2) CUMS significantly reduced the NMDAR subunits of GluN2B and GluN3 in the medial prefrontal cortex (mPFC), but not altered all seven NMDAR subunits in hippocampus and corpus callosum of rats; (3) subunit composition of NMDARs in corpus callosum was different from that in mPFC, PFC and hippocampus; and (4) the mRNA expressions of GluN2B, GluN3A and GluN3B in mPFC as well as mRNA expression of GluN2C in corpus callosum were correlated to sucrose preference in rats. These findings suggested that GluN2B and GluN3 in mPFC may contribute to the pathophysiology of depression.
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Affiliation(s)
- Jing Chen
- Molecular Medicine Diagnostic and Testing Center, Institute of Life Science, Chongqing Medical University, Chongqing, 400016, P. R. China
| | - Yanmin Luo
- Department of Physiology, Chongqing Medical University, Chongqing, 400016, P. R. China
| | - Xin Liang
- Department of Pathophysiology, Chongqing Medical University, Chongqing, 400016, P. R. China
| | - Xiangru Kong
- Department of Pediatric Surgical Oncology, Children’s Hospital of Chongqing Medical University, Chongqing, 400014, P. R. China
| | - Qian Xiao
- Department of Radioactive Medicine, Chongqing Medical University, Chongqing, 400016, P. R. China
| | - Jing Tang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, 400016, P. R. China
| | - Yingqiang Qi
- Molecular Medicine Diagnostic and Testing Center, Institute of Life Science, Chongqing Medical University, Chongqing, 400016, P. R. China
| | - Yong Tang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, 400016, P. R. China
| | - Yun Xiu
- Molecular Medicine Diagnostic and Testing Center, Institute of Life Science, Chongqing Medical University, Chongqing, 400016, P. R. China
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Kuzmina US, Zainullina LF, Vakhitov VA, Bakhtiyarova KZ, Vakhitova YV. The role of glutamate in the pathogenesis of multiple sclerosis. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:160-167. [DOI: 10.17116/jnevro2019119081160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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3
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Luo P, Liu D, Guo L. Protecting Oligodendrocytes by Targeting Non-Glutamate Receptors as a New Therapeutic Strategy for Ischemic Stroke. Pharmacology 2017. [PMID: 28637049 DOI: 10.1159/000477939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ischemic stroke has many devastating effects within the brain. At the cellular level, excitotoxicity has been a popular pharmacological target for therapeutics. To date, many clinical trials have been performed with drugs that target excitatory neurotransmitter receptors, such as NMDA receptor agonists. The results, however, have been lackluster. Most efforts to understand the impacts of excitotoxicity on the brain have focused primarily on neurons, and to a lesser degree, on gliocytes as cellular targets. Recent evidence suggests that oligodendrocytes (OLGs), the myelin-forming cells in the central nervous system, are damaged by ischemia in a manner completely different from that in neurons. Whereas ischemia primarily damages neurons through overactivation of ionotropic glutamate receptors, the ischemia damage in OLGs occurs through overactivation of H+-gated transient receptor potential channels. Given the differential mechanisms of ischemic injury between neurons and OLGs, strategies to target non-glutamate receptors to prevent OLG damage/demyelination deserve greater attention in drug development. Such strategies, combined with neuroprotective measures, could provide an excellent therapeutic avenue for the treatment of ischemic stroke.
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Affiliation(s)
- Pan Luo
- Department of Pharmacy, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Kalani A, Chaturvedi P, Kamat PK, Maldonado C, Bauer P, Joshua IG, Tyagi SC, Tyagi N. Curcumin-loaded embryonic stem cell exosomes restored neurovascular unit following ischemia-reperfusion injury. Int J Biochem Cell Biol 2016; 79:360-369. [PMID: 27594413 PMCID: PMC5067233 DOI: 10.1016/j.biocel.2016.09.002] [Citation(s) in RCA: 175] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/22/2016] [Accepted: 09/01/2016] [Indexed: 12/13/2022]
Abstract
We tested whether the combined nano-formulation, prepared with curcumin (anti-inflammatory and neuroprotective molecule) and embryonic stem cell exosomes (MESC-exocur), restored neurovascular loss following an ischemia reperfusion (IR) injury in mice. IR-injury was created in 8-10 weeks old mice and divided into two groups. Out of two IR-injured groups, one group received intranasal administration of MESC-exocur for 7days. Similarly, two sham groups were made and one group received MESC-exocur treatment. The study determined that MESC-exocur treatment reduced neurological score, infarct volume and edema following IR-injury. As compared to untreated IR group, MESC-exocur treated-IR group showed reduced inflammation and N-methyl-d-aspartate receptor expression. Treatment of MESC-exocur also reduced astrocytic GFAP expression and alleviated the expression of NeuN positive neurons in IR-injured mice. In addition, MESC-exocur treatment restored vascular endothelial tight (claudin-5 and occludin) and adherent (VE-cadherin) junction proteins in IR-injured mice as compared to untreated IR-injured mice. These results suggest that combining the potentials of embryonic stem cell exosomes and curcumin can help neurovascular restoration following ischemia-reperfusion injury in mice.
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Affiliation(s)
- Anuradha Kalani
- Department of Physiology, School of Medicine, University of Louisville, KY, USA.
| | - Pankaj Chaturvedi
- Department of Physiology, School of Medicine, University of Louisville, KY, USA
| | - Pradip K Kamat
- Department of Physiology, School of Medicine, University of Louisville, KY, USA
| | - Claudio Maldonado
- Department of Physiology, School of Medicine, University of Louisville, KY, USA; Department of Surgery, University of Louisville, KY, USA
| | - Philip Bauer
- Department of Surgery, University of Louisville, KY, USA
| | - Irving G Joshua
- Department of Physiology, School of Medicine, University of Louisville, KY, USA
| | - Suresh C Tyagi
- Department of Physiology, School of Medicine, University of Louisville, KY, USA
| | - Neetu Tyagi
- Department of Physiology, School of Medicine, University of Louisville, KY, USA
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5
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Lee S, Shin J, Lee M, Hong Y, Lee SK, Lee Y, Lkhagvasuren T, Kim DW, Yang YA, Chang KT, Hong Y. Melatonin combined with exercise cannot alleviate cerebral injury in a rat model of focal cerebral ischemia/reperfusion injury. Neural Regen Res 2015; 7:993-9. [PMID: 25722687 PMCID: PMC4341280 DOI: 10.3969/j.issn.1673-5374.2012.13.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 03/30/2012] [Indexed: 11/18/2022] Open
Abstract
Previous studies have demonstrated that melatonin combined with exercise can alleviate secondary damage after spinal cord injury in rats. Therefore, it is hypothesized that melatonin combined with exercise can also alleviate ischemic brain damage. In this study, adult rats were subjected to right middle cerebral artery occlusion after receiving 10 mg/kg melatonin or vehicle subcutaneously twice daily for 14 days. Forced exercise using an animal treadmill was performed at 20 m/min for 30 minutes per day for 6 days prior to middle cerebral artery occlusion. After middle cerebral artery occlusion, each rat received melatonin combined with exercise, melatonin or exercise alone equally for 7 days until sacrifice. Interestingly, rats receiving melatonin combined with exercise exhibited more severe neurological deficits than those receiving melatonin or exercise alone. Hypoxia-inducible factor 1α mRNA in the brain tissue was upregulated in rats receiving melatonin combined with exercise. Similarly, microtubule associated protein-2 mRNA expression was significantly upregulated in rats receiving melatonin alone. Chondroitin sulfate proteoglycan 4 (NG2) mRNA expression was significantly decreased in rats receiving melatonin combined with exercise as well as in rats receiving exercise alone. Furthermore, neural cell loss in the primary motor cortex was significantly reduced in rats receiving melatonin or exercise alone, but the change was not observed in rats receiving melatonin combined with exercise. These findings suggest that excessive intervention with melatonin, exercise or their combination may lead to negative effects on ischemia/reperfusion-induced brain damage.
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Affiliation(s)
- Seunghoon Lee
- Department of Rehabilitation Science in Interdisciplinary Ph.D. Program, Inje University, Gimhae 621-749, Republic of Korea
| | - Jinhee Shin
- Cardiovascular & Metabolic Disease Center, College of Biomedical Science & Engineering, Gimhae 621-749, Republic of Korea
| | - Minkyung Lee
- Department of Rehabilitation Science in Interdisciplinary Ph.D. Program, Inje University, Gimhae 621-749, Republic of Korea
| | - Yunkyung Hong
- Department of Rehabilitation Science in Interdisciplinary Ph.D. Program, Inje University, Gimhae 621-749, Republic of Korea
| | - Sang-Kil Lee
- Cardiovascular & Metabolic Disease Center, College of Biomedical Science & Engineering, Gimhae 621-749, Republic of Korea
| | - Youngjeon Lee
- Department of Rehabilitation Science in Interdisciplinary Ph.D. Program, Inje University, Gimhae 621-749, Republic of Korea
| | - Tserentogtokh Lkhagvasuren
- Department of Smart Foods & Drugs, School of Food & Life Sciences, Inje University, Gimhae 621-749, Republic of Korea
| | - Dong-Wook Kim
- Department of Pharmaceutical Engineering, College of Engineering, Inje University, Gimhae 621-749, Republic of Korea
| | - Young-Ae Yang
- Department of Rehabilitation Science in Interdisciplinary Ph.D. Program, Inje University, Gimhae 621-749, Republic of Korea
| | - Kyu-Tae Chang
- National Primate Research Center, Korea Research Institute of Biotechnology, Ochang 363-883, Republic of Korea
| | - Yonggeun Hong
- Department of Rehabilitation Science in Interdisciplinary Ph.D. Program, Inje University, Gimhae 621-749, Republic of Korea ; Cardiovascular & Metabolic Disease Center, College of Biomedical Science & Engineering, Gimhae 621-749, Republic of Korea ; National Primate Research Center, Korea Research Institute of Biotechnology, Ochang 363-883, Republic of Korea
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Dzamba D, Honsa P, Anderova M. NMDA Receptors in Glial Cells: Pending Questions. Curr Neuropharmacol 2013; 11:250-62. [PMID: 24179462 PMCID: PMC3648778 DOI: 10.2174/1570159x11311030002] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/08/2013] [Accepted: 02/02/2013] [Indexed: 01/28/2023] Open
Abstract
Glutamate receptors of the N-methyl-D-aspartate (NMDA) type are involved in many cognitive processes, including behavior, learning and synaptic plasticity. For a long time NMDA receptors were thought to be the privileged domain of neurons; however, discoveries of the last 25 years have demonstrated their active role in glial cells as well. Despite the large number of studies in the field, there are many unresolved questions connected with NMDA receptors in glia that are still a matter of debate. The main objective of this review is to shed light on these controversies by summarizing results from all relevant works concerning astrocytes, oligodendrocytes and polydendrocytes (also known as NG2 glial cells) in experimental animals, further extended by studies performed on human glia. The results are divided according to the study approach to enable a better comparison of how findings obtained at the mRNA level correspond with protein expression or functionality. Furthermore, special attention is focused on the NMDA receptor subunits present in the particular glial cell types, which give them special characteristics different from those of neurons – for example, the absence of Mg2+ block and decreased Ca2+ permeability. Since glial cells are implicated in important physiological and pathophysiological roles in the central nervous system (CNS), the last part of this review provides an overview of glial NMDA receptors with respect to ischemic brain injury.
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Affiliation(s)
- David Dzamba
- Department of Cellular Neurophysiology, Institute of Experimental Medicine AS CR, Prague, Czech Republic and Second Medical Faculty, Charles University, Prague, Czech Republic
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Azami Tameh A, Clarner T, Beyer C, Atlasi MA, Hassanzadeh G, Naderian H. Regional regulation of glutamate signaling during cuprizone-induced demyelination in the brain. Ann Anat 2013; 195:415-23. [PMID: 23711509 DOI: 10.1016/j.aanat.2013.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 02/25/2013] [Accepted: 03/18/2013] [Indexed: 12/14/2022]
Abstract
Glutamate excitotoxicity is associated with a wide range of neurodegenerative disorders and also seems to be involved in the pathology of demyelinating disorders such as multiple sclerosis (MS). Cuprizone-induced toxic demyelination shows clear characteristics of MS such as demyelination and axonal damage without the involvement of the innate immune system. In this study, we have evaluated glutamate signaling during cuprizone-induced demyelination in the white and gray matter of mouse brain by studying the expression of ionotropic and metabotropic glutamate-receptors and -transporters by Affymetrix gene array analysis, followed by real-time PCR and western blot analysis. Cellular localization of glutamate transporters was investigated by fluorescence double-labeling experiments. Comparing white and gray matter areas, the expression of glutamate receptors was region-specific. Among NMDA receptor subunits, NR2A was up-regulated in the demyelinated corpus callosum (CC), whereas the metabotropic glutamate receptor mGluR2 was down-regulated in demyelinated gray matter. Glutamate-aspartate transporter (GLAST) co-localizing with GFAP(+) astrocytes was increased in both demyelinated CC and telencephalic cortex, whereas Slc1a4 transporter was up-regulated only in CC. Our data indicate that cuprizone treatment affects glutamate-receptors and -transporters differently in gray and white matter brain areas revealing particularly regulation of GLAST and Slc1a4 compared with other genes. This might have an important influence on brain-region selective sensitivity to neurotoxic compounds and the progression of demyelination as has been reported for MS and other demyelinating neurological diseases.
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Affiliation(s)
- Abolfazl Azami Tameh
- Anatomical Sciences Research Center, Kashan University of Medical Sciences, Kashan, Iran; Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Aachen, Germany.
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8
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Rai S, Kamat PK, Nath C, Shukla R. A study on neuroinflammation and NMDA receptor function in STZ (ICV) induced memory impaired rats. J Neuroimmunol 2013; 254:1-9. [DOI: 10.1016/j.jneuroim.2012.08.008] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 08/14/2012] [Accepted: 08/17/2012] [Indexed: 11/16/2022]
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9
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Endothelial cells and astrocytes: a concerto en duo in ischemic pathophysiology. Int J Cell Biol 2012; 2012:176287. [PMID: 22778741 PMCID: PMC3388591 DOI: 10.1155/2012/176287] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 04/30/2012] [Indexed: 11/17/2022] Open
Abstract
The neurovascular/gliovascular unit has recently gained increased attention in cerebral ischemic research, especially regarding the cellular and molecular changes that occur in astrocytes and endothelial cells. In this paper we summarize the recent knowledge of these changes in association with edema formation, interactions with the basal lamina, and blood-brain barrier dysfunctions. We also review the involvement of astrocytes and endothelial cells with recombinant tissue plasminogen activator, which is the only FDA-approved thrombolytic drug after stroke. However, it has a narrow therapeutic time window and serious clinical side effects. Lastly, we provide alternative therapeutic targets for future ischemia drug developments such as peroxisome proliferator- activated receptors and inhibitors of the c-Jun N-terminal kinase pathway. Targeting the neurovascular unit to protect the blood-brain barrier instead of a classical neuron-centric approach in the development of neuroprotective drugs may result in improved clinical outcomes after stroke.
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Williams R, Buchheit CL, Berman NEJ, LeVine SM. Pathogenic implications of iron accumulation in multiple sclerosis. J Neurochem 2011; 120:7-25. [PMID: 22004421 DOI: 10.1111/j.1471-4159.2011.07536.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Iron, an essential element used for a multitude of biochemical reactions, abnormally accumulates in the CNS of patients with multiple sclerosis (MS). The mechanisms of abnormal iron deposition in MS are not fully understood, nor do we know whether these deposits have adverse consequences, that is, contribute to pathogenesis. With some exceptions, excess levels of iron are represented concomitantly in multiple deep gray matter structures often with bilateral representation, whereas in white matter, pathological iron deposits are usually located at sites of inflammation that are associated with veins. These distinct spatial patterns suggest disparate mechanisms of iron accumulation between these regions. Iron has been postulated to promote disease activity in MS by various means: (i) iron can amplify the activated state of microglia resulting in the increased production of proinflammatory mediators; (ii) excess intracellular iron deposits could promote mitochondria dysfunction; and (iii) improperly managed iron could catalyze the production of damaging reactive oxygen species (ROS). The pathological consequences of abnormal iron deposits may be dependent on the affected brain region and/or accumulation process. Here, we review putative mechanisms of enhanced iron uptake in MS and address the likely roles of iron in the pathogenesis of this disease.
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Affiliation(s)
- Rachel Williams
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Lee MC, Ting KK, Adams S, Brew BJ, Chung R, Guillemin GJ. Characterisation of the expression of NMDA receptors in human astrocytes. PLoS One 2010; 5:e14123. [PMID: 21152063 PMCID: PMC2994931 DOI: 10.1371/journal.pone.0014123] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 10/26/2010] [Indexed: 12/14/2022] Open
Abstract
Astrocytes have long been perceived only as structural and supporting cells within the central nervous system (CNS). However, the discovery that these glial cells may potentially express receptors capable of responding to endogenous neurotransmitters has resulted in the need to reassess astrocytic physiology. The aim of the current study was to characterise the expression of NMDA receptors (NMDARs) in primary human astrocytes, and investigate their response to physiological and excitotoxic concentrations of the known endogenous NMDAR agonists, glutamate and quinolinic acid (QUIN). Primary cultures of human astrocytes were used to examine expression of these receptors at the mRNA level using RT-PCR and qPCR, and at the protein level using immunocytochemistry. The functionality role of the receptors was assessed using intracellular calcium influx experiments and measuring extracellular lactate dehydrogenase (LDH) activity in primary cultures of human astrocytes treated with glutamate and QUIN. We found that all seven currently known NMDAR subunits (NR1, NR2A, NR2B, NR2C, NR2D, NR3A and NR3B) are expressed in astrocytes, but at different levels. Calcium influx studies revealed that both glutamate and QUIN could activate astrocytic NMDARs, which stimulates Ca2+ influx into the cell and can result in dysfunction and death of astrocytes. Our data also show that the NMDAR ion channel blockers, MK801, and memantine can attenuate glutamate and QUIN mediated cell excitotoxicity. This suggests that the mechanism of glutamate and QUIN gliotoxicity is at least partially mediated by excessive stimulation of NMDARs. The present study is the first to provide definitive evidence for the existence of functional NMDAR expression in human primary astrocytes. This discovery has significant implications for redefining the cellular interaction between glia and neurons in both physiological processes and pathological conditions.
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Affiliation(s)
- Ming-Chak Lee
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Ka Ka Ting
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Seray Adams
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Bruce J. Brew
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
- Departments of Neurology and HIV Medicine, St. Vincent's Hospital, Sydney, Australia
| | - Roger Chung
- NeuroRepair Group, Menzies Research Institute, University of Tasmania, Hobart, Tasmania, Australia
| | - Gilles J. Guillemin
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
- * E-mail:
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Huang C, Hu ZL, Wu WN, Yu DF, Xiong QJ, Song JR, Shu Q, Fu H, Wang F, Chen JG. Existence and distinction of acid-evoked currents in rat astrocytes. Glia 2010; 58:1415-24. [PMID: 20549751 DOI: 10.1002/glia.21017] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astrocytes are vital structures that support and/or protect neighboring neurons from pathology. Although it is generally accepted that glutamate receptors mediate most astrocyte effects, acid-evoked currents have recently attracted attention for their role in this regard. Here, we identified the existence and characteristics of acid-sensing ion channels (ASICs) and the transient receptor potential vanilloid type 1 (TRPV1) in astrocytes. There were two types of currents recorded under the application of acidic solution (pH 6.0) in cultured rat astrocytes. Transient currents were exhibited by 10% of the astrocytes, and sustained currents were exhibited by the other 90%, consistent with the features of ASIC and TRPV1 currents, respectively. Western blotting and immunofluorescence confirmed the expression of ASIC1, ASIC2a, ASIC3, and TRPV1 in cultured and in situ astrocytes. Unlike the ASICs expressed in neurons, which were mainly distributed in the cell membrane/cytoplasm, most of the ASICs in astrocytes were expressed in the nucleus. TRPV1 was more permeable to Na(+) in cultured astrocytes, which differed from the typical neuronal TRPV1 that was mainly permeable to Ca(2+). This study demonstrates that there are two kinds of acid-evoked currents in rat astrocytes, which may provide a new understanding about the functions of ligand-gated ion channels in astrocytes.
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Affiliation(s)
- Chao Huang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Brinkmann BG, Agarwal A, Sereda MW, Garratt AN, Müller T, Wende H, Stassart RM, Nawaz S, Humml C, Velanac V, Radyushkin K, Goebbels S, Fischer TM, Franklin RJ, Lai C, Ehrenreich H, Birchmeier C, Schwab MH, Nave KA. Neuregulin-1/ErbB signaling serves distinct functions in myelination of the peripheral and central nervous system. Neuron 2008; 59:581-95. [PMID: 18760695 DOI: 10.1016/j.neuron.2008.06.028] [Citation(s) in RCA: 248] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 04/18/2008] [Accepted: 06/27/2008] [Indexed: 10/21/2022]
Abstract
Understanding the control of myelin formation by oligodendrocytes is essential for treating demyelinating diseases. Neuregulin-1 (NRG1) type III, an EGF-like growth factor, is essential for myelination in the PNS. It is thus thought that NRG1/ErbB signaling also regulates CNS myelination, a view suggested by in vitro studies and the overexpression of dominant-negative ErbB receptors. To directly test this hypothesis, we generated a series of conditional null mutants that completely lack NRG1 beginning at different stages of neural development. Unexpectedly, these mice assemble normal amounts of myelin. In addition, double mutants lacking oligodendroglial ErbB3 and ErbB4 become myelinated in the absence of any stimulation by neuregulins. In contrast, a significant hypermyelination is achieved by transgenic overexpression of NRG1 type I or NRG1 type III. Thus, NRG1/ErbB signaling is markedly different between Schwann cells and oligodendrocytes that have evolved an NRG/ErbB-independent mechanism of myelination control.
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Affiliation(s)
- Bastian G Brinkmann
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen 37075, Germany
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14
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Dunlop SA. Activity-dependent plasticity: implications for recovery after spinal cord injury. Trends Neurosci 2008; 31:410-8. [DOI: 10.1016/j.tins.2008.05.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 05/27/2008] [Accepted: 05/27/2008] [Indexed: 12/29/2022]
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15
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Sanagi T, Yabe T, Yamada H. Gene transfer of PEDF attenuates ischemic brain damage in the rat middle cerebral artery occlusion model. J Neurochem 2008; 106:1841-54. [DOI: 10.1111/j.1471-4159.2008.05529.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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16
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Besancon E, Guo S, Lok J, Tymianski M, Lo EH. Beyond NMDA and AMPA glutamate receptors: emerging mechanisms for ionic imbalance and cell death in stroke. Trends Pharmacol Sci 2008; 29:268-75. [DOI: 10.1016/j.tips.2008.02.003] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Revised: 02/11/2008] [Accepted: 02/15/2008] [Indexed: 01/25/2023]
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17
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Carter CJ. eIF2B and oligodendrocyte survival: where nature and nurture meet in bipolar disorder and schizophrenia? Schizophr Bull 2007; 33:1343-53. [PMID: 17329232 PMCID: PMC2779884 DOI: 10.1093/schbul/sbm007] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Bipolar disorder and schizophrenia share common chromosomal susceptibility loci and many risk-promoting genes. Oligodendrocyte cell loss and hypomyelination are common to both diseases. A number of environmental risk factors including famine, viral infection, and prenatal or childhood stress may also predispose to schizophrenia or bipolar disorder. In cells, related stressors (starvation, viruses, cytokines, oxidative, and endoplasmic reticulum stress) activate a series of eIF2-alpha kinases, which arrest protein synthesis via the eventual inhibition, by phosphorylated eIF2-alpha, of the translation initiation factor eIF2B. Growth factors increase protein synthesis via eIF2B activation and counterbalance this system. The control of protein synthesis by eIF2-alpha kinases is also engaged by long-term potentiation and repressed by long-term depression, mediated by N-methyl-D-aspartate (NMDA) and metabotropic glutamate receptors. Many genes reportedly associated with both schizophrenia and bipolar disorder code for proteins within or associated with this network. These include NMDA (GRIN1, GRIN2A, GRIN2B) and metabotropic (GRM3, GRM4) glutamate receptors, growth factors (BDNF, NRG1), and many of their downstream signaling components or accomplices (AKT1, DAO, DAOA, DISC1, DTNBP1, DPYSL2, IMPA2, NCAM1, NOS1, NOS1AP, PIK3C3, PIP5K2A, PDLIM5, RGS4, YWHAH). They also include multiple gene products related to the control of the stress-responsive eIF2-alpha kinases (IL1B, IL1RN, MTHFR, TNF, ND4, NDUFV2, XBP1). Oligodendrocytes are particularly sensitive to defects in the eIF2B complex, mutations in which are responsible for vanishing white matter disease. The convergence of natural and genetic risk factors on this area in bipolar disorder and schizophrenia may help to explain the apparent vulnerability of this cell type in these conditions. This convergence may also help to reconcile certain arguments related to the importance of nature and nurture in the etiology of these psychiatric disorders. Both may affect common stress-related signaling pathways that dictate oligodendrocyte viability and synaptic plasticity.
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de Rivero Vaccari JC, Casey GP, Aleem S, Park WM, Corriveau RA. NMDA receptors promote survival in somatosensory relay nuclei by inhibiting Bax-dependent developmental cell death. Proc Natl Acad Sci U S A 2006; 103:16971-6. [PMID: 17077143 PMCID: PMC1636563 DOI: 10.1073/pnas.0608068103] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Naturally occurring cell death is a universal feature of developing nervous systems that plays an essential role in determining adult brain function. Yet little is known about the decisions that select a subset of CNS neurons for survival and cause others to die. We report that postnatal day 0 NMDA receptor subunit 1 (NMDAR1) knockout mice display an approximately 2-fold increase in cell death in the brainstem trigeminal complex (BSTC), including all four nuclei that receive somatosensory inputs from the face (principalis, oralis, interpolaris, and caudalis). Treatment with the NMDA receptor antagonist dizocilpine maleate (MK-801) for 24 h before birth also caused an increase in cell death that reached statistical significance in two of the four nuclei (oralis and interpolaris). The neonatal sensitivity to NMDA receptor hypofunction in the BSTC, and in its main thalamic target, the ventrobasal nucleus (VB), coincides with the peak of naturally occurring cell death and trigeminothalamic synaptogenesis. At embryonic day 17.5, before the onset of these events, NMDAR1 knockout does not affect cell survival in either the BSTC or the VB. Immunostaining for active caspase-3 and the neuronal marker Hu specifically confirms the presence of dying neurons in the BSTC and the VB of NMDAR1 knockout neonates. Finally, genetic deletion of Bax rescues these structures from the requirement for NMDA receptors to limit naturally occurring cell death. Taken together, the results indicate that NMDA receptors play a survival role for somatosensory relay neurons during synaptogenesis by inhibiting Bax-dependent developmental cell death.
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Affiliation(s)
| | - Gregory P. Casey
- *Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Salman Aleem
- *Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Won-Mee Park
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118; and
| | - Roderick A. Corriveau
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH 43614
- To whom correspondence should be sent at the present address:
Coriell Institute for Medical Research, 403 Haddon Avenue, Camden, NJ 08103. E-mail:
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