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Haddow K, Kind PC, Hardingham GE. NMDA Receptor C-Terminal Domain Signalling in Development, Maturity, and Disease. Int J Mol Sci 2022; 23:ijms231911392. [PMID: 36232696 PMCID: PMC9570437 DOI: 10.3390/ijms231911392] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/18/2022] Open
Abstract
The NMDA receptor is a Ca2+-permeant glutamate receptor which plays key roles in health and disease. Canonical NMDARs contain two GluN2 subunits, of which 2A and 2B are predominant in the forebrain. Moreover, the relative contribution of 2A vs. 2B is controlled both developmentally and in an activity-dependent manner. The GluN2 subtype influences the biophysical properties of the receptor through difference in their N-terminal extracellular domain and transmembrane regions, but they also have large cytoplasmic Carboxyl (C)-terminal domains (CTDs) which have diverged substantially during evolution. While the CTD identity does not influence NMDAR subunit specific channel properties, it determines the nature of CTD-associated signalling molecules and has been implicated in mediating the control of subunit composition (2A vs. 2B) at the synapse. Historically, much of the research into the differential function of GluN2 CTDs has been conducted in vitro by over-expressing mutant subunits, but more recently, the generation of knock-in (KI) mouse models have allowed CTD function to be probed in vivo and in ex vivo systems without heterologous expression of GluN2 mutants. In some instances, findings involving KI mice have been in disagreement with models that were proposed based on earlier approaches. This review will examine the current research with the aim of addressing these controversies and how methodology may contribute to differences between studies. We will also discuss the outstanding questions regarding the role of GluN2 CTD sequences in regulating NMDAR subunit composition, as well as their relevance to neurodegenerative disease and neurodevelopmental disorders.
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Affiliation(s)
- Kirsty Haddow
- UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Peter C. Kind
- UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Giles E. Hardingham
- UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
- Correspondence:
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Chen J, Zhuang Y, Zhang Y, Liao H, Liu R, Cheng J, Zhang Z, Sun J, Gao J, Wang X, Chen S, Zhang L, Che F, Wan Q. A synthetic BBB-permeable tripeptide GCF confers neuroprotection by increasing glycine in the ischemic brain. Front Pharmacol 2022; 13:950376. [PMID: 36046828 PMCID: PMC9420865 DOI: 10.3389/fphar.2022.950376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 06/29/2022] [Indexed: 11/20/2022] Open
Abstract
Background: We and others have previously demonstrated that glycine is neuroprotective in cerebral ischemia-reperfusion injury. But glycine has low permeability to the blood–brain barrier (BBB). To deliver glycine into the ischemic brain to confer neuroprotection, we designed a novel glycine-containing and BBB-permeable tripeptide, the H-glycine-cysteine-phenylalanine-OH (GCF). Methods: For the synthesis of GCF, phenylalanine was included to increase the BBB permeability of the tripeptide. Cysteine was conjugated with glycine to enable the release of glycine from GCF. With the use of immunofluorescence labeling and HPLC assays, we measured the distribution and level of GCF. We used TTC labeling, LDH release, and MTT assays to evaluate the neuroprotective effect of GCF. Results: Following intravenous injection in a rat model of cerebral ischemia-reperfusion injury, GCF was intensively distributed in the ischemic neurons. Intravenous injection of GCF, but not the non-cleavable acetyl-GCF, resulted in the elevation of glycine in the ischemic brain. GCF but not acetyl-GC conferred neuroprotection in ischemic stroke animals. Conclusion: GCF protects against cerebral ischemia-reperfusion injury in the rat. In contrast to peptide drugs that exert therapeutic effect by interfering with signaling interaction, GCF acts as a BBB shuttle and prodrug to deliver glycine to confer neuroprotection, representing a novel therapeutic strategy for acute ischemic stroke.
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Affiliation(s)
- Juan Chen
- Department of Neurology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Physiology, School of Medicine, Wuhan University, Wuhan, China
| | - Yang Zhuang
- Department of Physiology, School of Medicine, Wuhan University, Wuhan, China
| | - Ya Zhang
- Department of Physiology, School of Medicine, Wuhan University, Wuhan, China
| | - Huabao Liao
- Department of Physiology, School of Medicine, Wuhan University, Wuhan, China
| | - Rui Liu
- Department of Physiology, School of Medicine, Wuhan University, Wuhan, China
| | - Jing Cheng
- Department of Physiology, School of Medicine, Wuhan University, Wuhan, China
| | - Zhifeng Zhang
- Department of Physiology, School of Medicine, Wuhan University, Wuhan, China
| | - Jiangdong Sun
- Department of Pathophysiology, School of Basic Medicine, Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
| | - Jingchen Gao
- Department of Pathophysiology, School of Basic Medicine, Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
| | - Xiyuran Wang
- Department of Pathophysiology, School of Basic Medicine, Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
| | - Shujun Chen
- Department of Pathophysiology, School of Basic Medicine, Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
| | - Liang Zhang
- Krembil Research Institute, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Fengyuan Che
- Central Laboratory, Department of Neurology, Linyi People’s Hospital, Qingdao University, Linyi, China
- *Correspondence: Qi Wan, ; Fengyuan Che,
| | - Qi Wan
- Department of Pathophysiology, School of Basic Medicine, Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
- Qingdao Gui-Hong Intelligent Medical Technology Co., Ltd., Qingdao, China
- *Correspondence: Qi Wan, ; Fengyuan Che,
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Engin A, Engin AB. N-Methyl-D-Aspartate Receptor Signaling-Protein Kinases Crosstalk in Cerebral Ischemia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:259-283. [PMID: 33539019 DOI: 10.1007/978-3-030-49844-3_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Although stroke is very often the cause of death worldwide, the burden of ischemic and hemorrhagic stroke varies between regions and over time regarding differences in prognosis, prevalence of risk factors, and treatment strategies. Excitotoxicity, oxidative stress, dysfunction of the blood-brain barrier, neuroinflammation, and lysosomal membrane permeabilization, sequentially lead to the progressive death of neurons. In this process, protein kinases-related checkpoints tightly regulate N-methyl-D-aspartate (NMDA) receptor signaling pathways. One of the major hallmarks of cerebral ischemia is excitotoxicity, characterized by overactivation of glutamate receptors leading to intracellular Ca2+ overload and ultimately neuronal death. Thus, reduced expression of postsynaptic density-95 protein and increased protein S-nitrosylation in neurons is responsible for neuronal vulnerability in cerebral ischemia. In this chapter death-associated protein kinases, cyclin-dependent kinase 5, endoplasmic reticulum stress-induced protein kinases, hyperhomocysteinemia-related NMDA receptor overactivation, ephrin-B-dependent amplification of NMDA-evoked neuronal excitotoxicity and lysosomocentric hypothesis have been discussed.Consequently, ample evidences have demonstrated that enhancing extrasynaptic NMDA receptor activity triggers cell death after stroke. In this context, considering the dual roles of NMDA receptors in both promoting neuronal survival and mediating neuronal damage, selective augmentation of NR2A-containing NMDA receptor activation in the presence of NR2B antagonist may constitute a promising therapy for stroke.
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Affiliation(s)
- Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Ayse Basak Engin
- Department of Toxicology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
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Lei Y, Zhang ZF, Lei RX, Wang S, Zhuang Y, Liu AC, Wu Y, Chen J, Tang JC, Pan MX, Liu R, Liao WJ, Feng YG, Wan Q, Zheng M. DJ-1 Suppresses Cytoplasmic TDP-43 Aggregation in Oxidative Stress-Induced Cell Injury. J Alzheimers Dis 2019; 66:1001-1014. [PMID: 30372676 DOI: 10.3233/jad-180460] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
DJ-1 (also called PARK7) is a multifunctional redox-sensitive protein that is protective against oxidative stress-induced cell death. TAR DNA-binding protein 43 (TDP-43) is a major protein component of pathological inclusions in amyotrophic lateral sclerosis and frontotemporal dementia. Reducing aberrant aggregation of TDP-43 is a potential approach to prevent cell death. To investigate whether DJ-1 might inhibit TDP-43 aggregation to exert a protective effect in oxidative stress-induced injury, we tested the protein level and subcellular localization of TDP-43 and DJ-1 in SH-SY5Y cells transfected with wild-type DJ-1, DJ-1 mutant (L166P) cDNA, or DJ-1 siRNA. We show that oxidative stress induced by paraquat leads to the formation of cytosolic TDP-43 aggregation in SH-SY5Y cells. DJ-1 overexpression decreases paraquat-induced cytoplasmic accumulation of TDP-43 in SH-SY5Y cells and protects against paraquat-induced cell death. Transfection of DJ-1 L166P mutant or DJ-1 siRNA leads to increased cytosolic aggregation of TDP-43 in paraquat-treated SH-SY5Y cells and promotes cell death. These data suggest that DJ-1 may protect against oxidative stress-induced cell death through the suppression of cytoplasmic TDP-43 aggregation.
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Affiliation(s)
- Yang Lei
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Zhi-Feng Zhang
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China.,Department of Physiology, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei, China
| | - Rui-Xue Lei
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Shu Wang
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Yang Zhuang
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - An-Chun Liu
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Yan Wu
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Juan Chen
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Jun-Chun Tang
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Meng-Xian Pan
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Rui Liu
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, Wuhan University School of Medicine, Wuhan, China
| | - Wei-Jing Liao
- Center for Brain Clinic, Zhongnan Hospital, Wuhan University School of Medicine, Wuhan, China
| | - Yu-Gong Feng
- Research Institute of Neuroregeneration & Neurorehabilitation, and Department of Neurosurgery, Qingdao University, Qingdao, China
| | - Qi Wan
- Research Institute of Neuroregeneration & Neurorehabilitation, and Department of Neurosurgery, Qingdao University, Qingdao, China
| | - Mei Zheng
- Department of Neurology, Beijing University Third Hospital, Beijing, China
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5
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PINK1 Silencing Modifies Dendritic Spine Dynamics of Mouse Hippocampal Neurons. J Mol Neurosci 2019; 69:570-579. [DOI: 10.1007/s12031-019-01385-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 07/11/2019] [Indexed: 12/11/2022]
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Glycine triggers a non-ionotropic activity of GluN2A-containing NMDA receptors to confer neuroprotection. Sci Rep 2016; 6:34459. [PMID: 27694970 PMCID: PMC5046082 DOI: 10.1038/srep34459] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 09/14/2016] [Indexed: 11/08/2022] Open
Abstract
Ionotropic activation of NMDA receptors (NMDARs) requires agonist glutamate and co-agonist glycine. Here we show that glycine enhances the activation of cell survival-promoting kinase Akt in cultured cortical neurons in which both the channel activity of NMDARs and the glycine receptors are pre-inhibited. The effect of glycine is reduced by shRNA-mediated knockdown of GluN2A subunit-containing NMDARs (GluN2ARs), suggesting that a non-ionotropic activity of GluN2ARs mediates glycine-induced Akt activation. In support of this finding, glycine enhances Akt activation in HEK293 cells over-expressing GluN2ARs. The effect of glycine on Akt activation is sensitive to the antagonist of glycine-GluN1 binding site. As a functional consequence, glycine protects against excitotoxicity-induced neuronal death through the non-ionotropic activity of GluN2ARs and the neuroprotective effect is attenuated by Akt inhibition. Thus, this study reveals an unexpected role of glycine in eliciting a non-ionotropic activity of GluN2ARs to confer neuroprotection via Akt activation.
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Chen J, Zhuang Y, Zhang ZF, Wang S, Jin P, He C, Hu PC, Wang ZF, Li ZQ, Xia GM, Li G, Wang Y, Wan Q. Glycine confers neuroprotection through microRNA-301a/PTEN signaling. Mol Brain 2016; 9:59. [PMID: 27230112 PMCID: PMC4880874 DOI: 10.1186/s13041-016-0241-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 05/17/2016] [Indexed: 12/22/2022] Open
Abstract
Background Glycine is known to protect against neuronal death. However, the underlying mechanism remains to be elucidated. The microRNA-301a is involved in both biological and pathological processes. But it is not known whether microRNA-301a has a neuroprotective property. In this study, we aimed to determine whether glycine-induced neuroprotection requires microRNA-301a-dependent signaling. Results We provided the first evidence that glycine increased the expression of microRNA-301a in cultured rat cortical neurons and protected against cortical neuronal death through up-regulation of microRNA-301a after oxygen-glucose deprivation. MicroRNA-301a directly bound the predicted 3′UTR target sites of PTEN and reduced PTEN expression in cortical neurons. We revealed that PTEN down-regulation by microRNA-301a mediated glycine-induced neuroprotective effect following oxygen-glucose deprivation. Conclusions Our results suggest that 1) microRNA-301a is neuroprotective in oxygen-glucose deprivation-induced neuronal injury; 2) glycine is an upstream regulator of microRNA-301a; 3) glycine confers neuroprotection through microRNA-301a/PTEN signal pathway.
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Affiliation(s)
- Juan Chen
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China.,Department of Neurology, the Central Hospital of Wuhan, Wuhan, 430060, China
| | - Yang Zhuang
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China
| | - Zhi-Feng Zhang
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China
| | - Shu Wang
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China
| | - Ping Jin
- Department of Neurology, the Central Hospital of Wuhan, Wuhan, 430060, China
| | - Chunjiang He
- Department of Genetics, School of Basic Medical Sciences, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China
| | - Peng-Chao Hu
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China
| | - Ze-Fen Wang
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China
| | - Zhi-Qiang Li
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of Medicine, 169 Donghu Street, Wuhan, 430071, China
| | - Guang-Ming Xia
- Department of Neurology, the Central Hospital of Huanggang, Huanggang, 438000, China
| | - Gang Li
- Department of Neurology, the Central Hospital of Huanggang, Huanggang, 438000, China
| | - Yuan Wang
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China
| | - Qi Wan
- Department of Physiology, School of Basic Medical Sciences, Medical Research Institute, Wuhan University School of Medicine, 185 Donghu Street, Wuhan, 430071, China. .,Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of Medicine, 169 Donghu Street, Wuhan, 430071, China.
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8
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Sun Y, Zhang L, Chen Y, Zhan L, Gao Z. Therapeutic Targets for Cerebral Ischemia Based on the Signaling Pathways of the GluN2B C Terminus. Stroke 2015; 46:2347-53. [DOI: 10.1161/strokeaha.115.009314] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 06/09/2015] [Indexed: 12/18/2022]
Affiliation(s)
- Yongjun Sun
- From the Department of Pharmacy (Y.S., Y.C., L. Zhan, Z.G.), Hebei Research Center of Pharmaceutical and Chemical Engineering (Y.S., Z.G.), and State Key Laboratory Breeding Base—Hebei Province Key Laboratory of Molecular Chemistry for Drug (Z.G.), Hebei University of Science and Technology, Shijiazhuang, China; and Department of Pathophysiology, Hebei Medical University, Shijiazhuang, China (L. Zhang)
| | - Linan Zhang
- From the Department of Pharmacy (Y.S., Y.C., L. Zhan, Z.G.), Hebei Research Center of Pharmaceutical and Chemical Engineering (Y.S., Z.G.), and State Key Laboratory Breeding Base—Hebei Province Key Laboratory of Molecular Chemistry for Drug (Z.G.), Hebei University of Science and Technology, Shijiazhuang, China; and Department of Pathophysiology, Hebei Medical University, Shijiazhuang, China (L. Zhang)
| | - You Chen
- From the Department of Pharmacy (Y.S., Y.C., L. Zhan, Z.G.), Hebei Research Center of Pharmaceutical and Chemical Engineering (Y.S., Z.G.), and State Key Laboratory Breeding Base—Hebei Province Key Laboratory of Molecular Chemistry for Drug (Z.G.), Hebei University of Science and Technology, Shijiazhuang, China; and Department of Pathophysiology, Hebei Medical University, Shijiazhuang, China (L. Zhang)
| | - Liying Zhan
- From the Department of Pharmacy (Y.S., Y.C., L. Zhan, Z.G.), Hebei Research Center of Pharmaceutical and Chemical Engineering (Y.S., Z.G.), and State Key Laboratory Breeding Base—Hebei Province Key Laboratory of Molecular Chemistry for Drug (Z.G.), Hebei University of Science and Technology, Shijiazhuang, China; and Department of Pathophysiology, Hebei Medical University, Shijiazhuang, China (L. Zhang)
| | - Zibin Gao
- From the Department of Pharmacy (Y.S., Y.C., L. Zhan, Z.G.), Hebei Research Center of Pharmaceutical and Chemical Engineering (Y.S., Z.G.), and State Key Laboratory Breeding Base—Hebei Province Key Laboratory of Molecular Chemistry for Drug (Z.G.), Hebei University of Science and Technology, Shijiazhuang, China; and Department of Pathophysiology, Hebei Medical University, Shijiazhuang, China (L. Zhang)
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9
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Synaptojanin 1 mutation in Parkinson's disease brings further insight into the neuropathological mechanisms. BIOMED RESEARCH INTERNATIONAL 2014; 2014:289728. [PMID: 25302295 PMCID: PMC4181773 DOI: 10.1155/2014/289728] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 08/26/2014] [Indexed: 12/13/2022]
Abstract
Synaptojanin 1 (SYNJ1) is a phosphoinositide phosphatase highly expressed in nerve terminals. Its two phosphatase domains dephosphorylate phosphoinositides present in membranes, while its proline-rich domain directs protein-protein interactions with synaptic components, leading to efficient recycling of synaptic vesicles in neurons. Triplication of SYNJ1 in Down's syndrome is responsible for higher level of phosphoinositides, enlarged endosomes, and learning deficits. SYNJ1 downregulation in Alzheimer's disease models is protective towards amyloid-beta peptide (Aβ) toxicity. One missense mutation in one of SYNJ1 functional domains was recently incriminated in an autosomal recessive form of early-onset Parkinson's disease (PD). In the third decade of life, these patients develop progressive Parkinsonism with bradykinesia, dystonia, and variable atypical symptoms such as cognitive decline, seizures, and eyelid apraxia. The identification of this new gene, together with the fact that most of the known PD proteins play a role in synaptic vesicle recycling and lipid metabolism, points out that synaptic maintenance is a key player in PD pathological mechanisms. Studying PD genes as a network regulating synaptic activity could bring insight into understanding the neuropathological processes of PD and help identify new genes at fault in this devastating disorder.
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10
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Zheng M, Shi Y, Fan D. Nuclear TAR DNA-binding protein 43: A new target for amyotrophic lateral sclerosis treatment. Neural Regen Res 2014; 8:3284-95. [PMID: 25206650 PMCID: PMC4145946 DOI: 10.3969/j.issn.1673-5374.2013.35.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Abnormal TAR DNA-binding protein 43 (TDP-43) inclusion bodies can be detected in the degenerative neurons of amyotrophic lateral sclerosis. In this study, we induced chronic oxidative stress injury by applying malonate to cultured mouse cortical motor neurons. In the later stages of the malonate insult, TDP-43 expression reduced in the nuclei and transferred to the cytoplasm. This was accompanied by neuronal death, mimicking the pathological changes in TDP-43 that are seen in patients with amyotrophic lateral sclerosis. Interestingly, in the early stages of the response to malonate treatment, nuclear TDP-43 expression increased, and neurons remained relatively intact, without inclusion bodies or fragmentation. Therefore, we hypothesized that the increase of nuclear TDP-43 expression might be a pro-survival factor against oxidative stress injury. This hypothesis was confirmed by an in vitro transgenic experiment, in which overexpression of wild type mouse TDP-43 in cultured cortical motor neurons significantly reduced malonate-induced neuronal death. Our findings suggest that the loss of function of TDP-43 is an important cause of neuronal degeneration, and upregulation of nuclear TDP-43 expression might be neuroprotective in amyotrophic lateral sclerosis.
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Affiliation(s)
- Mei Zheng
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
| | - Yujie Shi
- School of Pharmaceutical Sciences, Peking University, Beijing 100083, China
| | - Dongsheng Fan
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
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11
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Lai TW, Zhang S, Wang YT. Excitotoxicity and stroke: identifying novel targets for neuroprotection. Prog Neurobiol 2013; 115:157-88. [PMID: 24361499 DOI: 10.1016/j.pneurobio.2013.11.006] [Citation(s) in RCA: 775] [Impact Index Per Article: 70.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/28/2013] [Accepted: 11/29/2013] [Indexed: 01/22/2023]
Abstract
Excitotoxicity, the specific type of neurotoxicity mediated by glutamate, may be the missing link between ischemia and neuronal death, and intervening the mechanistic steps that lead to excitotoxicity can prevent stroke damage. Interest in excitotoxicity began fifty years ago when monosodium glutamate was found to be neurotoxic. Evidence soon demonstrated that glutamate is not only the primary excitatory neurotransmitter in the adult brain, but also a critical transmitter for signaling neurons to degenerate following stroke. The finding led to a number of clinical trials that tested inhibitors of excitotoxicity in stroke patients. Glutamate exerts its function in large by activating the calcium-permeable ionotropic NMDA receptor (NMDAR), and different subpopulations of the NMDAR may generate different functional outputs, depending on the signaling proteins directly bound or indirectly coupled to its large cytoplasmic tail. Synaptic activity activates the GluN2A subunit-containing NMDAR, leading to activation of the pro-survival signaling proteins Akt, ERK, and CREB. During a brief episode of ischemia, the extracellular glutamate concentration rises abruptly, and stimulation of the GluN2B-containing NMDAR in the extrasynaptic sites triggers excitotoxic neuronal death via PTEN, cdk5, and DAPK1, which are directly bound to the NMDAR, nNOS, which is indirectly coupled to the NMDAR via PSD95, and calpain, p25, STEP, p38, JNK, and SREBP1, which are further downstream. This review aims to provide a comprehensive summary of the literature on excitotoxicity and our perspectives on how the new generation of excitotoxicity inhibitors may succeed despite the failure of the previous generation of drugs.
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Affiliation(s)
- Ted Weita Lai
- Graduate Institute of Clinical Medical Science, China Medical University, 91 Hsueh-Shih Road, 40402 Taichung, Taiwan; Translational Medicine Research Center, China Medical University Hospital, 2 Yu-De Road, 40447 Taichung, Taiwan.
| | - Shu Zhang
- Translational Medicine Research Center, China Medical University Hospital, 2 Yu-De Road, 40447 Taichung, Taiwan; Brain Research Center, University of British Columbia, 2211 Wesbrook Mall, V6T 2B5 Vancouver, Canada
| | - Yu Tian Wang
- Brain Research Center, University of British Columbia, 2211 Wesbrook Mall, V6T 2B5 Vancouver, Canada.
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12
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Dagda RK, Pien I, Wang R, Zhu J, Wang KZQ, Callio J, Banerjee TD, Dagda RY, Chu CT. Beyond the mitochondrion: cytosolic PINK1 remodels dendrites through protein kinase A. J Neurochem 2013; 128:864-77. [PMID: 24151868 DOI: 10.1111/jnc.12494] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 10/01/2013] [Accepted: 10/04/2013] [Indexed: 11/27/2022]
Abstract
The subcellular compartmentalization of kinase activity allows for regulation of distinct cellular processes involved in cell differentiation or survival. The PTEN-induced kinase 1 (PINK1), which is linked to Parkinson's disease, is a neuroprotective kinase localized to cytosolic and mitochondrial compartments. While mitochondrial targeting of PINK1 is important for its activities regulating mitochondrial homeostasis, the physiological role of the cytosolic pool of PINK1 remains unknown. Here, we demonstrate a novel role for cytosolic PINK1 in neuronal differentiation/neurite maintenance. Over-expression of wild-type PINK1, but not a catalytically inactive form of PINK1(K219M), promoted neurite outgrowth in SH-SY5Y cells and increased dendritic lengths in primary cortical and midbrain dopaminergic neurons. To identify the subcellular pools of PINK1 involved in promoting neurite outgrowth, we transiently transfected cells with PINK1 constructs designed to target PINK1 to the outer mitochondrial membrane (OMM-PINK1) or restrict PINK1 to the cytosol (ΔN111-PINK1). Both constructs blocked cell death associated with loss of endogenous PINK1. However, transient expression of ΔN111-PINK1, but not of OMM-PINK1 or ΔN111-PINK1(K219M), promoted dendrite outgrowth in primary neurons, and rescued the decreased dendritic arborization of PINK1-deficient neurons. Mechanistically, the cytosolic pool of PINK1 regulated neurite morphology through enhanced anterograde transport of dendritic mitochondria and amplification of protein kinase A-related signaling pathways. Our data support a novel role for PINK1 in regulating dendritic morphogenesis.
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Affiliation(s)
- Ruben K Dagda
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
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Evidence of oxidative stress in young and aged DJ-1-deficient mice. FEBS Lett 2013; 587:1562-70. [PMID: 23587484 DOI: 10.1016/j.febslet.2013.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 03/28/2013] [Accepted: 04/03/2013] [Indexed: 02/02/2023]
Abstract
Loss of DJ-1 function contributes to pathogenesis in Parkinson's disease. Here, we investigate the impact of aging and DJ-1 deficiency in transgenic mice. Ventral midbrain from young DJ-1-deficient mice revealed no change in 4-hydroxy-2-nonenal (4-HNE), but HSP60, HSP40 and striatal dopamine turnover were significantly elevated compared to wildtype. In aged mice, the chaperone response observed in wildtype animals was absent from DJ-1-deficient transgenics, and nigral 4-HNE immunoreactivity was enhanced. These changes were concomitant with increased striatal dopamine levels and uptake. Thus, increased oxidants and diminished protein quality control may contribute to nigral oxidative damage with aging in the model.
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Vaz AR, Silva SL, Barateiro A, Falcão AS, Fernandes A, Brito MA, Brites D. Selective vulnerability of rat brain regions to unconjugated bilirubin. Mol Cell Neurosci 2011; 48:82-93. [PMID: 21708263 DOI: 10.1016/j.mcn.2011.06.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 06/06/2011] [Accepted: 06/10/2011] [Indexed: 12/22/2022] Open
Abstract
Hippocampus is one of the brain regions most vulnerable to unconjugated bilirubin (UCB) encephalopathy, although cerebellum also shows selective yellow staining in kernicterus. We previously demonstrated that UCB induces oxidative stress in cortical neurons, disruption of neuronal network dynamics, either in developing cortical or hippocampal neurons, and that immature cortical neurons are more prone to UCB-induced injury. Here, we studied if immature rat neurons isolated from cortex, cerebellum and hippocampus present distinct features of oxidative stress and cell dysfunction upon UCB exposure. We also explored whether oxidative damage and its regulation contribute to neuronal dysfunction induced by hyperbilirubinemia, considering neurite extension and ramification, as well as cell death. Our results show that UCB induces nitric oxide synthase expression, as well as production of nitrites and cyclic guanosine monophosphate in immature neurons, mainly in those from hippocampus. After exposure to UCB, hippocampal neurons presented the highest content of reactive oxygen species, disruption of glutathione redox status and cell death, when compared to neurons from cortex or cerebellum. In particular, the results indicate that cells exposed to UCB undertake an adaptive response that involves DJ-1, a multifunctional neuroprotective protein implicated in the maintenance of cellular oxidation status. However, longer neuronal exposure to UCB caused down-regulation of DJ-1 expression, especially in hippocampal neurons. In addition, a greater impairment in neurite outgrowth and branching following UCB treatment was also noticed in immature neurons from hippocampus. Interestingly, pre-incubation with N-acetylcysteine, a precursor of glutathione synthesis, protected neurons from UCB-induced oxidative stress and necrotic cell death, preventing DJ-1 down-regulation and neuritic impairment. Taken together, these data point to oxidative injury and disruption of neuritic network as hallmarks in hippocampal susceptibility to UCB. Most importantly, they also suggest that local differences in glutathione content may account to the different susceptibility between brain regions exposed to UCB.
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Affiliation(s)
- Ana Rita Vaz
- Research Institute for Medicines and Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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