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Nishimura Y, Masaki K, Matsuse D, Yamaguchi H, Tanaka T, Matsuo E, Hayashida S, Watanabe M, Matsushita T, Sadashima S, Sasagasako N, Yamasaki R, Isobe N, Iwaki T, Kira J. Early and extensive alterations of glial connexins, distal oligodendrogliopathy type demyelination, and nodal/paranodal pathology are characteristic of multiple system atrophy. Brain Pathol 2022; 33:e13131. [PMID: 36368713 PMCID: PMC10154368 DOI: 10.1111/bpa.13131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022] Open
Abstract
The pathological hallmark of multiple system atrophy (MSA) is aberrant accumulation of phosphorylated α-synuclein in oligodendrocytes, forming glial cytoplasmic inclusions (GCIs). Extensive demyelination occurs particularly in the olivopontocerebellar and striatonigral pathways, but its precise mechanism remains elusive. Glial connexins (Cxs), which form gap junction channels between astrocytes and oligodendrocytes, play critical roles in myelin maintenance, and have not been studied in MSA. Therefore, we immunohistochemically investigated glial Cx changes in the cerebellar afferent fibers in 15 autopsied patients with MSA. We classified demyelinating lesions into three stages based on Klüver-Barrera staining: early (Stage I), intermediate (Stage II), and late (Stage III) stages showing subtle, moderate, and severe myelin reduction, respectively. Myelin-associated glycoprotein, but not myelin oligodendrocyte glycoprotein, was preferentially decreased in Stage I, suggesting distal oligodendrogliopathy type demyelination. Accumulation of phosphorylated α-synuclein in oligodendrocytes was frequently seen in Stage I but less frequently observed in Stages II and III. Tubulin polymerization-promoting protein (TPPP/p25α)-positive oligodendrocytes were preserved in Stage I but successively decreased in Stages II and III. Even at Stage I, Cx32 was nearly absent from myelin, despite the relative preservation of other nodal proteins, such as neurofascin, claudin-11/oligodendrocyte-specific protein, and contactin-associated protein 1, which successively decreased in the later stages. Cx32 was re-distributed in the oligodendrocyte cytoplasm and co-localized with GCIs. Cx47 gradually decreased at the oligodendrocyte surface in a stage-dependent manner but was not co-localized with GCIs. Astrocytic Cx43 was down-regulated in Stage I but up-regulated in Stages II and III, reflecting astrogliosis. Cx43/Cx47 gap junctions significantly decreased from Stage I to III. Activated microglia/macrophages and T cells infiltrated in Stage I rather than Stages II and III. Therefore, early and extensive alterations of glial Cxs, particularly Cx32 loss, occur in MSA and may accelerate distal oligodendrogliopathy type demyelination and nodal/paranodal dysfunction through disruption of inter-glial communication.
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Affiliation(s)
- Yuji Nishimura
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Katsuhisa Masaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Dai Matsuse
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Hiroo Yamaguchi
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Tatsunori Tanaka
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
- Sumitomo Pharma Osaka Japan
| | - Eriko Matsuo
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Shotaro Hayashida
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Mitsuru Watanabe
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Takuya Matsushita
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Shoko Sadashima
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
- Department of Neuropathology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Naokazu Sasagasako
- Department of Neurology, Neuro‐Muscular Center National Omuta Hospital Fukuoka Japan
| | - Ryo Yamasaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Noriko Isobe
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Toru Iwaki
- Department of Neuropathology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Jun‐ichi Kira
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
- Translational Neuroscience Center, Graduate School of Medicine, and School of Pharmacy at Fukuoka International University of Health and Welfare Ookawa Japan
- Department of Neurology, Brain and Nerve Center Fukuoka Central Hospital Fukuoka Japan
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Khan A, Kuriachan G, Mahalakshmi R. Cellular Interactome of Mitochondrial Voltage-Dependent Anion Channels: Oligomerization and Channel (Mis)Regulation. ACS Chem Neurosci 2021; 12:3497-3515. [PMID: 34503333 DOI: 10.1021/acschemneuro.1c00429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Voltage-dependent anion channels (VDACs) of the outer mitochondrial membrane are known conventionally as metabolite flux proteins. However, research findings in the past decade have revealed the multifaceted regulatory roles of VDACs, from governing cellular physiology and mitochondria-mediated apoptosis to directly regulating debilitating cancers and neurodegenerative diseases. VDACs achieve these diverse functions by establishing isoform-dependent stereospecific interactomes in the cell with the cytosolic constituents and endoplasmic reticulum complexes, and the machinery of the mitochondrial compartments. VDACs are now increasingly recognized as regulatory hubs of the cell. Not surprisingly, even the transient misregulation of VDACs results directly in mitochondrial dysfunction. Additionally, human VDACs are now implicated in interaction with aggregation-prone cytosolic proteins, including Aβ, tau, and α-synuclein, contributing directly to the onset of Alzheimer's and Parkinson's diseases. Deducing the interaction dynamics and mechanisms can lead to VDAC-targeted peptide-based therapeutics that can alleviate neurodegenerative states. This review succinctly presents the latest findings of the VDAC interactome, and the mode(s) of VDAC-dependent regulation of biochemical physiology. We also discuss the relevance of VDACs in pathophysiological states and aggregation-associated diseases and address how VDACs will facilitate the development of next-generation precision medicines.
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Affiliation(s)
- Altmash Khan
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462066, India
| | - Gifty Kuriachan
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462066, India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462066, India
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Reyes JF, Ekmark-Léwen S, Perdiki M, Klingstedt T, Hoffmann A, Wiechec E, Nilsson P, Nilsson KPR, Alafuzoff I, Ingelsson M, Hallbeck M. Accumulation of alpha-synuclein within the liver, potential role in the clearance of brain pathology associated with Parkinson's disease. Acta Neuropathol Commun 2021; 9:46. [PMID: 33743820 PMCID: PMC7980682 DOI: 10.1186/s40478-021-01136-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 02/21/2021] [Indexed: 11/16/2022] Open
Abstract
Alpha-synuclein (α-syn) aggregation is the hallmark pathological lesion in brains of patients with Parkinson's disease (PD) and related neurological disorders characterized as synucleinopathies. Accumulating evidence now indicates that α-syn deposition is also present within the gut and other peripheral organs outside the central nervous system (CNS). In the current study, we demonstrate for the first time that α-syn pathology also accumulates within the liver, the main organ responsible for substance clearance and detoxification. We further demonstrate that cultured human hepatocytes readily internalize oligomeric α-syn assemblies mediated, at least in part, by the gap junction protein connexin-32 (Cx32). Moreover, we identified a time-dependent accumulation of α-syn within the liver of three different transgenic (tg) mouse models expressing human α-syn under CNS-specific promoters, despite the lack of α-syn mRNA expression within the liver. Such a brain-to-liver transmission route could be further corroborated by detection of α-syn pathology within the liver of wild type mice one month after a single striatal α-syn injection. In contrast to the synucleinopathy models, aged mice modeling AD rarely show any amyloid-beta (Aß) deposition within the liver. In human post-mortem liver tissue, we identified cases with neuropathologically confirmed α-syn pathology containing α-syn within hepatocellular structures to a higher degree (75%) than control subjects without α-syn accumulation in the brain (57%). Our results reveal that α-syn accumulates within the liver and may be derived from the brain or other peripheral sources. Collectively, our findings indicate that the liver may play a role in the clearance and detoxification of pathological proteins in PD and related synucleinopathies.
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Affiliation(s)
- Juan F Reyes
- Department of Biomedical and Clinical Sciences (BKV), Linköping University, 581 85, Linköping, Sweden.
- Department of Clinical Pathology, Linköping University, 581 85, Linköping, Sweden.
| | - Sara Ekmark-Léwen
- Department of Public Health and Caring Sciences, Section of Geriatrics, Uppsala University, Uppsala, Sweden
| | - Marina Perdiki
- Department of Biomedical and Clinical Sciences (BKV), Linköping University, 581 85, Linköping, Sweden
- Department of Clinical Pathology, Linköping University, 581 85, Linköping, Sweden
| | - Therése Klingstedt
- Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - Alana Hoffmann
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Emilia Wiechec
- Department of Biomedical and Clinical Sciences (BKV), Linköping University, 581 85, Linköping, Sweden
- Department of Otorhinolaryngology, Anesthetics, Operations and Special Surgery Center, Linköping University, 581 85, Linköping, Sweden
| | - Per Nilsson
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, 171 64, Solna, Sweden
| | - K Peter R Nilsson
- Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - Irina Alafuzoff
- Department of Pathology, Uppsala University Hospital, Uppsala, Sweden
| | - Martin Ingelsson
- Department of Public Health and Caring Sciences, Section of Geriatrics, Uppsala University, Uppsala, Sweden
| | - Martin Hallbeck
- Department of Biomedical and Clinical Sciences (BKV), Linköping University, 581 85, Linköping, Sweden
- Department of Clinical Pathology, Linköping University, 581 85, Linköping, Sweden
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4
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Li M, Hu J, Yuan X, Shen L, Zhu L, Luo Q. Hepcidin Decreases Rotenone-Induced α-Synuclein Accumulation via Autophagy in SH-SY5Y Cells. Front Mol Neurosci 2020; 13:560891. [PMID: 33177988 PMCID: PMC7596286 DOI: 10.3389/fnmol.2020.560891] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 09/11/2020] [Indexed: 12/11/2022] Open
Abstract
Parkinson’s disease (PD) is a neurodegenerative disorder, and the hallmarks of this disease include iron deposition and α-synuclein (α-syn) aggregation. Hepcidin could reduce iron in the central and peripheral nervous systems. Here, we hypothesized that hepcidin could further decrease α-syn accumulation via reducing iron. Therefore, rotenone or α-syn was introduced into human neuroblastoma SH-SY5Y cells to imitate the pathological progress of PD in vitro. This study investigated the clearance effects of hepcidin on α-syn induced by a relatively low concentration of rotenone exposure or α-syn overexpression to elucidate the potential clearance pathway involved in this process. We demonstrated that SH-SY5Y cell viability was impaired after rotenone treatment in a dose-dependent manner. α-syn expression and iron content increased under a low concentration rotenone (25 nM for 3 days) treatment in SH-SY5Y cells. Pre-treatment with hepcidin peptide suppressed the abovementioned effects of rotenone. However, hepcidin did not affect treatment with rotenone under high iron conditions. Hepcidin also played a role in reducing α-syn accumulation in rotenone and α-syn overexpression conditions. We identified that the probable clearance effect of hepcidin on α-syn was mediated by the autophagy pathway using pretreatment with autophagy inhibitors (3-MA and CQ) and detection of autophagy protein markers (LC3II/I and p62). In conclusion, hepcidin eliminated α-syn expression via the autophagy pathway in rotenone-treated and α-syn overexpression SH-SY5Y cells. This study highlights that hepcidin may offer a potential therapeutic perspective in α-syn accumulation diseases.
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Affiliation(s)
- Meiqi Li
- Department of Physiology and Hypoxic Biomedicine, Institute of Special Environmental Medicine and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jianan Hu
- Department of Physiology and Hypoxic Biomedicine, Institute of Special Environmental Medicine and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xiaoyu Yuan
- Department of Emergency, Affiliated Hospital of Nantong University, Nantong, China
| | - Lihua Shen
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, China
| | - Li Zhu
- Department of Physiology and Hypoxic Biomedicine, Institute of Special Environmental Medicine and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Qianqian Luo
- Department of Physiology and Hypoxic Biomedicine, Institute of Special Environmental Medicine and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
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5
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Maldifassi MC, Momboisse F, Guerra MJ, Vielma AH, Maripillán J, Báez-Matus X, Flores-Muñoz C, Cádiz B, Schmachtenberg O, Martínez AD, Cárdenas AM. The interplay between α7 nicotinic acetylcholine receptors, pannexin-1 channels and P2X7 receptors elicit exocytosis in chromaffin cells. J Neurochem 2020; 157:1789-1808. [PMID: 32931038 DOI: 10.1111/jnc.15186] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 08/18/2020] [Accepted: 09/04/2020] [Indexed: 12/20/2022]
Abstract
Pannexin-1 (Panx1) forms plasma membrane channels that allow the exchange of small molecules between the intracellular and extracellular compartments, and are involved in diverse physiological and pathological responses in the nervous system. However, the signaling mechanisms that induce their opening still remain elusive. Here, we propose a new mechanism for Panx1 channel activation through a functional crosstalk with the highly Ca2+ permeable α7 nicotinic acetylcholine receptor (nAChR). Consistent with this hypothesis, we found that activation of α7 nAChRs induces Panx1-mediated dye uptake and ATP release in the neuroblastoma cell line SH-SY5Y-α7. Using membrane permeant Ca2+ chelators, total internal reflection fluorescence microscopy in SH-SY5Y-α7 cells expressing a membrane-tethered GCAMP3, and Src kinase inhibitors, we further demonstrated that Panx1 channel opening depends on Ca2+ signals localized in submembrane areas, as well as on Src kinases. In turn, Panx1 channels amplify cytosolic Ca2+ signals induced by the activation of α7 nAChRs, by a mechanism that seems to involve ATP release and P2X7 receptor activation, as hydrolysis of extracellular ATP with apyrase or blockage of P2X7 receptors with oxidized ATP significantly reduces the α7 nAChR-Ca2+ signal. The physiological relevance of this crosstalk was also demonstrated in neuroendocrine chromaffin cells, wherein Panx1 channels and P2X7 receptors contribute to the exocytotic release of catecholamines triggered by α7 nAChRs, as measured by amperometry. Together these findings point to a functional coupling between α7 nAChRs, Panx1 channels and P2X7 receptors with physiological relevance in neurosecretion.
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Affiliation(s)
- María C Maldifassi
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | | | - María J Guerra
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Alex H Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Jaime Maripillán
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ximena Báez-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Doctorado en Ciencias, Universidad de Valparaíso, Chile
| | - Bárbara Cádiz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Magister en Ciencias Biológicas, Universidad de Valparaíso, Chile
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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Prommahom A, Dharmasaroja P. Effects of eEF1A2 knockdown on autophagy in an MPP +-induced cellular model of Parkinson's disease. Neurosci Res 2020; 164:55-69. [PMID: 32275913 DOI: 10.1016/j.neures.2020.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/16/2020] [Accepted: 03/30/2020] [Indexed: 11/17/2022]
Abstract
1-Methyl-4-phenylpyridinium ion (MPP+) is widely used to induce a cellular model of Parkinson's disease (PD) in dopaminergic cell lines. Downregulation of the protein translation elongation factor 1 alpha (eEF1A) has been reported in the brain tissue of PD patients. eEF1A2, an isoform of eEF1A, is associated with lysosome biogenesis that involves the autophagy process. However, the role of eEF1A2 on autophagic activity in PD has not been elucidated. In this work, we investigated the role of eEF1A2 on autophagy using eEF1A2 siRNA knockdown in differentiated SH-SY5Y neuronal cells treated with MPP+. We found that eEF1A2 was upregulated in differentiated cells, which could be silenced by eEF1A2 siRNA. Significantly, cells treated with MPP+ after eEF1A2 knockdown showed a decreased number of LC3 puncta, decreased LC3-II/LC3-I ratio, and decreased phospho-Beclin-1, compared to the MPP+ alone group. These cells showed extensive areas of mitochondria damage, with a reduction of mitochondrial membrane potential, but reduced mitophagy as indicated by the reduced colocalization of LC3 puncta with damaged mitochondria. Cells with eEF1A2 siRNA plus MPP+ treatment aggravated α-synuclein accumulation but reduced colocalization with LC3. As a result, eEF1A2 knockdown decreased viability, increased apoptotic nuclei, increased caspase-3/7 activation and increased cleaved caspase-3 when cells were treated with MPP+. These results suggest that eEF1A2 is essential for dopaminergic neuron survival against MPP+, in part through autophagy regulation.
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Affiliation(s)
- Athinan Prommahom
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Permphan Dharmasaroja
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
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7
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He JT, LI XY, Yang L, Zhao X. Astroglial connexins and cognition: memory formation or deterioration? Biosci Rep 2020; 40:BSR20193510. [PMID: 31868207 PMCID: PMC6954363 DOI: 10.1042/bsr20193510] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 01/20/2023] Open
Abstract
Connexins are the membrane proteins that form high-conductance plasma membrane channels and are the important constituents of gap junctions and hemichannels. Among different types of connexins, connexin 43 is the most widely expressed and studied gap junction proteins in astrocytes. Due to the key involvement of astrocytes in memory impairment and abundant expression of connexins in astrocytes, astroglial connexins have been projected as key therapeutic targets for Alzheimer's disease. On the other hand, the role of connexin gap junctions and hemichannels in memory formation and consolidation has also been reported. Moreover, deletion of these proteins and loss of gap junction communication result in loss of short-term spatial memory. Accordingly, both memory formation and memory deteriorating functions of astrocytes-located connexins have been documented. Physiologically expressed connexins may be involved in the memory formation, while pathologically increased expression of connexins with consequent excessive activation of astrocytes may induce neuronal injury and cognitive decline. The present review describes the memory formation as well as memory deteriorating functions of astroglial connexins in memory disorders of different etiology with possible mechanisms.
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Affiliation(s)
- Jin-Ting He
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, 130033, Jilin Province, China
| | - Xiao-Yan LI
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, 130033, Jilin Province, China
| | - Le Yang
- Department of Endocrinology, The People’s Hospital of Jilin Province, Changchun 130031, China
| | - Xin Zhao
- Department of Paediatrics, The First Hospital of Jilin University, Changchun, Jilin 130021, China
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8
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Reyes JF, Sackmann C, Hoffmann A, Svenningsson P, Winkler J, Ingelsson M, Hallbeck M. Binding of α-synuclein oligomers to Cx32 facilitates protein uptake and transfer in neurons and oligodendrocytes. Acta Neuropathol 2019; 138:23-47. [PMID: 30976973 PMCID: PMC6570706 DOI: 10.1007/s00401-019-02007-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 04/03/2019] [Accepted: 04/03/2019] [Indexed: 12/11/2022]
Abstract
The intercellular transfer of alpha-synuclein (α-syn) has been implicated in the progression of Parkinson's disease (PD) and multiple system atrophy (MSA). The cellular mechanisms underlying this process are now beginning to be elucidated. In this study, we demonstrate that the gap junction protein connexin-32 (Cx32) is centrally involved in the preferential uptake of α-syn oligomeric assemblies (oα-syn) in neurons and oligodendrocytes. In vitro, we demonstrate a clear correlation between Cx32 expression and oα-syn uptake. Pharmacological and genetic strategies targeting Cx32 successfully blocked oα-syn uptake. In cellular and transgenic mice modeling PD and MSA, we observed significant upregulation of Cx32 which correlates with α-syn accumulation. Notably, we could also demonstrate a direct interaction between α-syn and Cx32 in two out of four human PD cases that was absent in all four age-matched controls. These data are suggestive of a link between Cx32 and PD pathophysiology. Collectively, our results provide compelling evidence for Cx32 as a novel target for therapeutic intervention in PD and related α-synucleinopathies.
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Affiliation(s)
- Juan F Reyes
- Department of Clinical Pathology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
| | - Christopher Sackmann
- Department of Clinical Pathology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Alana Hoffmann
- Department of Molecular Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Per Svenningsson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Jürgen Winkler
- Department of Molecular Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Martin Ingelsson
- Section of Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Martin Hallbeck
- Department of Clinical Pathology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
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Ahmadian E, Eftekhari A, Samiei M, Maleki Dizaj S, Vinken M. The role and therapeutic potential of connexins, pannexins and their channels in Parkinson's disease. Cell Signal 2019; 58:111-118. [DOI: 10.1016/j.cellsig.2019.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/10/2019] [Accepted: 03/10/2019] [Indexed: 02/07/2023]
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10
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Marvian AT, Koss DJ, Aliakbari F, Morshedi D, Outeiro TF. In vitro models of synucleinopathies: informing on molecular mechanisms and protective strategies. J Neurochem 2019; 150:535-565. [PMID: 31004503 DOI: 10.1111/jnc.14707] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 02/06/2023]
Abstract
Alpha-synuclein (α-Syn) is a central player in Parkinson's disease (PD) and in a spectrum of neurodegenerative diseases collectively known as synucleinopathies. The protein was first associated with PD just over 20 years ago, when it was found to (i) be a major component of Lewy bodies and (ii) to be also associated with familial forms of PD. The characterization of α-Syn pathology has been achieved through postmortem studies of human brains. However, the identification of toxic mechanisms associated with α-Syn was only achieved through the use of experimental models. In vitro models are highly accessible, enable relatively rapid studies, and have been extensively employed to address α-Syn-associated neurodegeneration. Given the diversity of models used and the outcomes of the studies, a cumulative and comprehensive perspective emerges as indispensable to pave the way for further investigations. Here, we subdivided in vitro models of α-Syn pathology into three major types: (i) models simulating α-Syn fibrillization and the formation of different aggregated structures in vitro, (ii) models based on the intracellular expression of α-Syn, reporting on pathogenic conditions and cellular dysfunctions induced, and (iii) models using extracellular treatment with α-Syn aggregated species, reporting on sites of interaction and their downstream consequences. In summary, we review the underlying molecular mechanisms discovered and categorize protective strategies, in order to pave the way for future studies and the identification of effective therapeutic strategies. This article is part of the Special Issue "Synuclein".
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Affiliation(s)
- Amir Tayaranian Marvian
- Department of Neurology, School of Medicine, Technical University of Munich, Munich, Germany.,Department of Translational Neurodegeneration, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - David J Koss
- Institute of Neuroscience, The Medical School, Newcastle University, Newcastle Upon Tyne, UK
| | - Farhang Aliakbari
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.,Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Dina Morshedi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Tiago Fleming Outeiro
- Institute of Neuroscience, The Medical School, Newcastle University, Newcastle Upon Tyne, UK.,Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,University Medical Center Göttingen, Göttingen, Germany.,Max Planck Institute for Experimental Medicine, Göttingen, Germany
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11
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Mayorquin LC, Rodriguez AV, Sutachan JJ, Albarracín SL. Connexin-Mediated Functional and Metabolic Coupling Between Astrocytes and Neurons. Front Mol Neurosci 2018; 11:118. [PMID: 29695954 PMCID: PMC5905222 DOI: 10.3389/fnmol.2018.00118] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/27/2018] [Indexed: 01/24/2023] Open
Abstract
The central nervous system (CNS) requires sophisticated regulation of neuronal activity. This modulation is partly accomplished by non-neuronal cells, characterized by the presence of transmembrane gap junctions (GJs) and hemichannels (HCs). This allows small molecule diffusion to guarantee neuronal synaptic activity and plasticity. Astrocytes are metabolically and functionally coupled to neurons by the uptake, binding and recycling of neurotransmitters. In addition, astrocytes release metabolites, such as glutamate, glutamine, D-serine, adenosine triphosphate (ATP) and lactate, regulating synaptic activity and plasticity by pre- and postsynaptic mechanisms. Uncoupling neuroglial communication leads to alterations in synaptic transmission that can be detrimental to neuronal circuit function and behavior. Therefore, understanding the pathways and mechanisms involved in this intercellular communication is fundamental for the search of new targets that can be used for several neurological disease treatments. This review will focus on molecular mechanisms mediating physiological and pathological coupling between astrocytes and neurons through GJs and HCs.
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Affiliation(s)
- Lady C Mayorquin
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Andrea V Rodriguez
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Jhon-Jairo Sutachan
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Sonia L Albarracín
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
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Barreca D, Currò M, Bellocco E, Ficarra S, Laganà G, Tellone E, Laura Giunta M, Visalli G, Caccamo D, Galtieri A, Ientile R. Neuroprotective effects of phloretin and its glycosylated derivative on rotenone-induced toxicity in human SH-SY5Y neuronal-like cells. Biofactors 2017; 43:549-557. [PMID: 28401997 DOI: 10.1002/biof.1358] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/08/2017] [Accepted: 02/19/2017] [Indexed: 12/31/2022]
Abstract
Phloretin and phlorizin are the two strong natural antioxidants whose biological and pharmacological applications are rapidly growing in different human pathological conditions. The neuroprotective activity of the two flavonoids has been analyzed on cell culture of neuroblastoma cells. The neuroprotective activity of the two flavonoids has been analyzed on cell culture of neuroblastoma cells and evaluated by testing cell vitality, mitochondrial transmembrane potential and ROS production, antioxidant enzymes detection, activation of caspase 3, DNA damage, protein carbonylation, lipid peroxidation, and superoxide anion scavenging activity. Incubation of cells with rotenone caused cell death and significant increase in intracellular reactive oxygen species, activation of caspase 3, and variation in mitochondrial transmembrane potential. Although, rotenone exposure caused a significant increase of antioxidant enzymes, high levels of lipid peroxidation were also observed. Phloretin or phlorizin, at micromolar concentration, reduced rotenone-induced cell death by scavenging ability against superoxide anion radical, one of the main effectors of rotenone toxicity at level of mitochondrial respiratory chain complex I. Under our experimental conditions, a reduction of the intracellular ROS levels with consequent normalization of the aforementioned antioxidant enzymes occurred. Concomitantly, we observed the inhibition of caspase 3 activity and DNA damage. This study shows the promising neuroprotective ability of the two dihydrochalcones able to protect human differentiated neuroblastoma cells (commonly used as model of Parkinson's disease) from injury induced by rotenone, actively scavenging ROS, normalizing mitochondrial transmembrane potential and consequently avoiding energy depletion. © 2017 BioFactors, 43(4):549-557, 2017.
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Affiliation(s)
- Davide Barreca
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Monica Currò
- Department of Biomedical Sciences, Dental Sciences and Morpho-functional Imaging, Polyclinic Hospital University, Via C. Valeria, Messina, Italy
| | - Ersilia Bellocco
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Silvana Ficarra
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Giuseppina Laganà
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Ester Tellone
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Maria Laura Giunta
- Department of Biomedical Sciences, Dental Sciences and Morpho-functional Imaging, Polyclinic Hospital University, Via C. Valeria, Messina, Italy
| | - Giuseppa Visalli
- Department of Biomedical Sciences, Dental Sciences and Morpho-functional Imaging, Polyclinic Hospital University, Via C. Valeria, Messina, Italy
| | - Daniela Caccamo
- Department of Biomedical Sciences, Dental Sciences and Morpho-functional Imaging, Polyclinic Hospital University, Via C. Valeria, Messina, Italy
| | - Antonio Galtieri
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Riccardo Ientile
- Department of Biomedical Sciences, Dental Sciences and Morpho-functional Imaging, Polyclinic Hospital University, Via C. Valeria, Messina, Italy
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Hu Y, Deng L, Zhang J, Fang X, Mei P, Cao X, Lin J, Wei Y, Zhang X, Xu R. A Pooling Genome-Wide Association Study Combining a Pathway Analysis for Typical Sporadic Parkinson's Disease in the Han Population of Chinese Mainland. Mol Neurobiol 2015; 53:4302-18. [PMID: 26227905 DOI: 10.1007/s12035-015-9331-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 07/01/2015] [Indexed: 01/23/2023]
Abstract
Genome-wide association studies (GWAS) on sporadic Parkinson's disease (sPD) are mainly conducted in European and American populations at present, and the Han populations of Chinese mainland (HPCM) almost have not been studied yet. Here, we conducted a pooling GWAS combining a pathway analysis with 862,198 autosomal single nucleotide polymorphisms of IlluminaHumanOmniZhongHua-8 in 250 sPD and 250 controls from HPCM precluded toxicant exposure, age, and heavy coffee drinking habit interference. We revealed that among the 22 potential loci implicated, PRDM2/KIAA1026 (kgp8090149), TSG1/MANEA (kgp154172), PDE10A (kgp8130520), MDGA2 (rs9323124), ATPBD4/LOC100288892 (kgp11333367), ZFP64/TSHZ2 (kgp4156164), PAQR3/ARD1B (kgp9482779), FLJ23172/FNDC3B (kgp760898), C18orf1 (kgp348599), FLJ43860/NCRNA00051 (kgp4105983), CYP1B1/C2orf58 (kgp11353523), WNT9A/LOC728728 (rs849898), ANXA1/LOC100130911 (rs10746953), FLJ35379/LOC100132423 (kgp9550589), PLEKHN1 (kgp7172368), DMRT2/SMARCA2 (kgp10769919), ZNF396/INO80C (rs1362858), C3orf67/LOC339902 (rs6783485), LOC285194/IGSF11 (rs1879553), FGF10/MRPS30 (rs13153459), BARX1/PTPDC1 (kgp6542803), and COL5 A2 (rs11186), the peak significance was at the kgp4105983 of FLJ43860 gene in chromosome 8, the first top strongest associated locus with sPD was PRDM2 (kgp8090149) in chromosome 1, and the 24 pathways including 100 significantly associated genes were strongly associated with sPD from HPCM. The 40 genes were shared by at least two pathways. The most possible associated pathways with sPD were axon guidance, ECM-receptor interaction, neuroactive ligand-receptor interaction, tight junction, focal adhesion, gap junction, long-term depression, drug metabolism-cytochrome P450, adherens junction, endocytosis, and protein digestion and absorption. Our results indicated that these loci, pathways, and their related genes might be involved in the pathogenesis of sPD from HPCM and provided some novel evidences for further searching the genetic pathogenesis of sPD.
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Affiliation(s)
- Yakun Hu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Libing Deng
- Institute of Translational Medicine, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Jie Zhang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Science, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Xin Fang
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Puming Mei
- Institute of Translational Medicine, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Xuebing Cao
- Department of Neurology, The Affiliated Union Hospital of Huazhong Technological University, Wuhan, 430006, Hubei, China
| | - Jiari Lin
- Institute of Translational Medicine, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Yi Wei
- Institute of Translational Medicine, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Xiong Zhang
- Department of Neurology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangdong Neuroscience Institute, Guangzhou, 510080, Guangdong, China.
| | - Renshi Xu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China.
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Schwab BC, Heida T, Zhao Y, van Gils SA, van Wezel RJA. Pallidal gap junctions-triggers of synchrony in Parkinson's disease? Mov Disord 2014; 29:1486-94. [PMID: 25124148 PMCID: PMC4307646 DOI: 10.1002/mds.25987] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 06/30/2014] [Accepted: 07/11/2014] [Indexed: 12/27/2022] Open
Abstract
Although increased synchrony of the neural activity in the basal ganglia may underlie the motor deficiencies exhibited in Parkinson's disease (PD), how this synchrony arises, propagates through the basal ganglia, and changes under dopamine replacement remains unknown. Gap junctions could play a major role in modifying this synchrony, because they show functional plasticity under the influence of dopamine and after neural injury. In this study, confocal imaging was used to detect connexin-36, the major neural gap junction protein, in postmortem tissues of PD patients and control subjects in the putamen, subthalamic nucleus (STN), and external and internal globus pallidus (GPe and GPi, respectively). Moreover, we quantified how gap junctions affect synchrony in an existing computational model of the basal ganglia. We detected connexin-36 in the human putamen, GPe, and GPi, but not in the STN. Furthermore, we found that the number of connexin-36 spots in PD tissues increased by 50% in the putamen, 43% in the GPe, and 109% in the GPi compared with controls. In the computational model, gap junctions in the GPe and GPi strongly influenced synchrony. The basal ganglia became especially susceptible to synchronize with input from the cortex when gap junctions were numerous and high in conductance. In conclusion, connexin-36 expression in the human GPe and GPi suggests that gap junctional coupling exists within these nuclei. In PD, neural injury and dopamine depletion could increase this coupling. Therefore, we propose that gap junctions act as a powerful modulator of synchrony in the basal ganglia.
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Affiliation(s)
- Bettina C Schwab
- Applied Analysis, MIRA Institute of Technical Medicine and Biomedical Technology, University of TwenteEnschede, The Netherlands
- Biomedical Signals and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of TwenteEnschede, The Netherlands
| | - Tjitske Heida
- Biomedical Signals and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of TwenteEnschede, The Netherlands
| | - Yan Zhao
- Biomedical Signals and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of TwenteEnschede, The Netherlands
| | - Stephan A van Gils
- Applied Analysis, MIRA Institute of Technical Medicine and Biomedical Technology, University of TwenteEnschede, The Netherlands
| | - Richard J A van Wezel
- Biomedical Signals and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of TwenteEnschede, The Netherlands
- Biophysics, Donders Institute for Brain, Cognition and Behavior, Radboud UniversityNijmegen, The Netherlands
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15
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Takeuchi H, Suzumura A. Gap junctions and hemichannels composed of connexins: potential therapeutic targets for neurodegenerative diseases. Front Cell Neurosci 2014; 8:189. [PMID: 25228858 PMCID: PMC4151093 DOI: 10.3389/fncel.2014.00189] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/19/2014] [Indexed: 12/03/2022] Open
Abstract
Microglia are macrophage-like resident immune cells that contribute to the maintenance of homeostasis in the central nervous system (CNS). Abnormal activation of microglia can cause damage in the CNS, and accumulation of activated microglia is a characteristic pathological observation in neurologic conditions such as trauma, stroke, inflammation, epilepsy, and neurodegenerative diseases. Activated microglia secrete high levels of glutamate, which damages CNS cells and has been implicated as a major cause of neurodegeneration in these conditions. Glutamate-receptor blockers and microglia inhibitors (e.g., minocycline) have been examined as therapeutic candidates for several neurodegenerative diseases; however, these compounds exerted little therapeutic benefit because they either perturbed physiological glutamate signals or suppressed the actions of protective microglia. The ideal therapeutic approach would hamper the deleterious roles of activated microglia without diminishing their protective effects. We recently found that abnormally activated microglia secrete glutamate via gap-junction hemichannels on the cell surface. Moreover, administration of gap-junction inhibitors significantly suppressed excessive microglial glutamate release and improved disease symptoms in animal models of neurologic conditions such as stroke, multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer's disease. Recent evidence also suggests that neuronal and glial communication via gap junctions amplifies neuroinflammation and neurodegeneration. Elucidation of the precise pathologic roles of gap junctions and hemichannels may lead to a novel therapeutic strategies that can slow and halt the progression of neurodegenerative diseases.
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Affiliation(s)
- Hideyuki Takeuchi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University Nagoya, Japan
| | - Akio Suzumura
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University Nagoya, Japan
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16
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Intracellular processing of disease-associated α-synuclein in the human brain suggests prion-like cell-to-cell spread. Neurobiol Dis 2014; 69:76-92. [DOI: 10.1016/j.nbd.2014.05.020] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/29/2014] [Accepted: 05/17/2014] [Indexed: 01/13/2023] Open
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17
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Affiliation(s)
- Hideyuki Takeuchi
- Department of Neuroimmunology; Research Institute of Environmental Medicine; Nagoya University; Nagoya Japan
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18
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Condello S, Currò M, Ferlazzo N, Costa G, Visalli G, Caccamo D, Pisani LR, Costa C, Calabresi P, Ientile R, Pisani F. Protective effects of zonisamide against rotenone-induced neurotoxicity. Neurochem Res 2013; 38:2631-9. [PMID: 24142350 DOI: 10.1007/s11064-013-1181-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 10/03/2013] [Accepted: 10/14/2013] [Indexed: 02/08/2023]
Abstract
Zonisamide (ZNS), an antiepileptic drug having beneficial effects also against Parkinson's disease symptoms, has proven to display an antioxidant effects in different experimental models. In the present study, the effects of ZNS on rotenone-induced cell injury were investigated in human neuroblastoma SH-SY5Y cells differentiated towards a neuronal phenotype. Cell cultures were exposed for 24 h to 500 nM rotenone with or without pre-treatment with 10-100 μM ZNS. Then, the following parameters were analyzed: (a) cell viability; (b) intracellular reactive oxygen species production; (c) mitochondrial transmembrane potential; (d) cell necrosis and apoptosis; (e) caspase-3 activity. ZNS dose-dependently suppressed rotenone-induced cell damage through a decrease in intracellular ROS production, and restoring mitochondrial membrane potential. Similarly to ZNS effects, the treatment with N-acetyl-cysteine (100 μM) displayed significant protective effects against rotenone-induced ROS production and Δψm at 4 and 12 h respectively, reaching the maximal extent at 24 h. Additionally, ZNS displayed antiapoptotic effects, as demonstrated by flow cytometric analysis of annexin V/propidium iodide double staining, and significant attenuated rotenone-increased caspase 3 activity. On the whole, these findings suggest that ZNS preserves mitochondrial functions and counteracts apoptotic signalling mechanisms mainly by an antioxidant action. Thus, ZNS might have beneficial effect against neuronal cell degeneration in different experimental models involving mitochondrial dysfunction.
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Affiliation(s)
- Salvatore Condello
- Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, AOU Policlinico "G. Martino", Via C. Valeria, 98125, Messina, Italy
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19
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Lu L, Zhang C, Cai Q, Lu Q, Duan C, Zhu Y, Yang H. Voltage-dependent anion channel involved in the α-synuclein-induced dopaminergic neuron toxicity in rats. Acta Biochim Biophys Sin (Shanghai) 2013; 45:170-8. [PMID: 23291291 DOI: 10.1093/abbs/gms114] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Inclusion bodies containing the neural protein α-synuclein (α-syn) are observed in several neurodegenerative diseases, including Parkinson's disease (PD). Furthermore, over-expression of α-syn in rat brain partly mimics the neuropathological and behavioral features of PD by triggering the degeneration of dopaminergic neurons in the substantia nigra (SN). Mitochondrial dysfunction is also central to PD pathogenesis, and α-syn is found in the mitochondria. However, the precise mechanisms of α-syn-induced neurotoxicity remain elusive. To examine the potential mechanisms of α-syn-induced neurodegeneration, we over-expressed α-syn in the SN of rats using a recombinant adeno-associated viral vector (rAAV-syn). Immunohistochemical and immunogold labeling results indicated that α-syn was successfully over-expressed in the SN and striatum after vector injection. The number of tyrosine hydroxylase-positive (dopaminergic) neurons was significantly reduced in rats injected with rAAV-syn when compared with control rats. Compared with control rats, the density of α-syn-conjugated gold particles was greater in the axons, cytoplasm, nuclei, and notably also in the mitochondria of SN neurons in rAAV-syn-injected rats. In addition, SN neurons transfected with rAAV-syn exhibited swollen mitochondria with discontinuous outer membranes and internal vacuole-like structures, strongly suggesting α-syn-induced mitochondrial dysfunction. Mitochondria in rAAV-syn-injected rats were also observed in autophagosomes. α-Syn co-immunoprecipitated with voltage-dependent anion channel 1 (VDAC1), a component of the mitochondrial permeability transition pore (mPTP) that induces mitochondrial uncoupling and apoptosis. Over-expression of α-syn may cause the degeneration of dopaminergic neurons through an interaction with mitochondrial VDAC1, which leads to mPTP activation, mitochondrial uncoupling, and cell death.
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Affiliation(s)
- Lingling Lu
- Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100069, China
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20
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Dual effects of α-synuclein on neurotoxicity induced by low dosage of rotenone are dependent on exposure time in dopaminergic neuroblastoma cells. SCIENCE CHINA-LIFE SCIENCES 2010; 53:590-7. [DOI: 10.1007/s11427-010-0104-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Accepted: 06/16/2009] [Indexed: 11/30/2022]
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21
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Orellana JA, Sáez PJ, Shoji KF, Schalper KA, Palacios-Prado N, Velarde V, Giaume C, Bennett MVL, Sáez JC. Modulation of brain hemichannels and gap junction channels by pro-inflammatory agents and their possible role in neurodegeneration. Antioxid Redox Signal 2009; 11:369-99. [PMID: 18816186 PMCID: PMC2713807 DOI: 10.1089/ars.2008.2130] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In normal brain, neurons, astrocytes, and oligodendrocytes, the most abundant and active cells express pannexins and connexins, protein subunits of two families forming membrane channels. Most available evidence indicates that in mammals endogenously expressed pannexins form only hemichannels and connexins form both gap junction channels and hemichannels. Whereas gap junction channels connect the cytoplasm of contacting cells and coordinate electric and metabolic activity, hemichannels communicate the intra- and extracellular compartments and serve as a diffusional pathway for ions and small molecules. A subthreshold stimulation by acute pathological threatening conditions (e.g., global ischemia subthreshold for cell death) enhances neuronal Cx36 and glial Cx43 hemichannel activity, favoring ATP release and generation of preconditioning. If the stimulus is sufficiently deleterious, microglia become overactivated and release bioactive molecules that increase the activity of hemichannels and reduce gap junctional communication in astroglial networks, depriving neurons of astrocytic protective functions, and further reducing neuronal viability. Continuous glial activation triggered by low levels of anomalous proteins expressed in several neurodegenerative diseases induce glial hemichannel and gap junction channel disorders similar to those of acute inflammatory responses triggered by ischemia or infectious diseases. These changes are likely to occur in diverse cell types of the CNS and contribute to neurodegeneration during inflammatory process.
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Affiliation(s)
- Juan A Orellana
- Departamento de Ciencias Fisiológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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22
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Dinh K, Poindexter BJ, Barnes JL, Schiess MC, Bick RJ. Fluorescence microscopy and 3D image reconstruction of cytokine initiated disruption of the Parkinson disease associated proteins alpha-synuclein, tau and ubiquitin in cultured glial cells. Cytokine 2009; 45:179-83. [PMID: 19157893 DOI: 10.1016/j.cyto.2008.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 08/28/2008] [Accepted: 12/11/2008] [Indexed: 01/01/2023]
Abstract
Human derived glioblastoma cells were cultured and treated with cytokines interleukin-6 (IL6), tumor necrosis factor alpha (TNF) and interferon-gamma (IFN) and imaged by fluorescence deconvolution microscopy to localize alpha-synuclein, tau and ubiquitin. Exposures were for short (2 h) and prolonged times (up to 96 h), with doses at both low (10 ng/ml), and high (100 ng/ml) concentrations. Further experiments used additive doses up to 200 ng/ml (2 x 100 ng), mimicking a super-infection state. Single, low doses of the cytokines initiated changes in levels of intracellular proteins, but these changes, be they increases or decreases, were not sustained, so we added higher doses of cytokine to the culture medium or fresh aliquots of cytokines over time. Finally, we treated cells with high, single doses of cytokine (200 ng/ml), to try to sustain perturbations of the proteins with cytokines. IFN caused a disruption and reduction of peripheral synuclein, TNF treatment resulted in increased levels of ubiquitin and IL6 disrupted and appeared to fragment tau. Of note, each of the proteins was found in a specific locale, tau being perinuclear, ubiquitin residing in the cytoplasm, and alpha-synuclein occupying the tips of cellular processes, exhibiting the characteristics of an adhesion protein/molecule [Word count=198].
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Affiliation(s)
- Kha Dinh
- Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, 6431 Fannin Street, MSB 2.288, Houston, TX 77030, USA.
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23
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Cheung YT, Lau WKW, Yu MS, Lai CSW, Yeung SC, So KF, Chang RCC. Effects of all-trans-retinoic acid on human SH-SY5Y neuroblastoma as in vitro model in neurotoxicity research. Neurotoxicology 2009; 30:127-35. [DOI: 10.1016/j.neuro.2008.11.001] [Citation(s) in RCA: 375] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 11/03/2008] [Accepted: 11/03/2008] [Indexed: 11/24/2022]
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Riveles K, Huang LZ, Quik M. Cigarette smoke, nicotine and cotinine protect against 6-hydroxydopamine-induced toxicity in SH-SY5Y cells. Neurotoxicology 2008; 29:421-7. [PMID: 18359086 PMCID: PMC2486261 DOI: 10.1016/j.neuro.2008.02.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 01/23/2008] [Accepted: 02/05/2008] [Indexed: 11/22/2022]
Abstract
Epidemiological studies consistently demonstrate a reduced incidence of Parkinson's disease in smokers. As an approach to evaluate whether nicotine in tobacco may be involved in this apparent protective effect, we compared the effect of mainstream 1R4F cigarette smoke solutions, which contain chemicals inhaled by active smokers, and nicotine against 6-hydroxydopamine (6-OHDA)-induced toxicity in an in vitro cell culture system. For this purpose we used terminally differentiated SH-SY5Y neuroblastoma cells that exhibit a catecholaminergic phenotype and express nicotinic receptors. Cells were pre-incubated for 24 h in mainstream-cigarette smoke solutions (0.06, 0.2, or 0.6 cigarette puffs/ml) made from University of Kentucky 1R4F research brand cigarettes, followed by the addition of 6-OHDA for another 24-48 h. The 0.2, but not 0.06, puffs/ml dose, significantly protected against 6-OHDA-induced toxicity in SH-SY5Y cells. This dose yielded final nicotine concentrations of approximately 5 x 10(-7) M, which is similar to plasma smoking levels. Although the 0.6 puffs/ml dose caused significant toxicity on its own, it also appeared to protect against 6-OHDA-induced damage. We next tested the effect of nicotine, as well as its metabolite cotinine. These agents protected against the toxic effects of 6-OHDA in SH-SY5Y cells at concentrations ranging from 10(-7) to 10(-5) M. These combined results support the idea that nicotine is one of the components in cigarette smoke that has a protective effect against neurotoxic insults. These data suggest that nicotine may be of potential therapeutic value for Parkinson's disease.
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Affiliation(s)
| | | | - Maryka Quik
- The Parkinson’s Institute, Sunnyvale, CA 94085
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25
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Battisti C, Formichi P, Radi E, Federico A. Oxidative-stress-induced apoptosis in PBLs of two patients with Parkinson disease secondary to alpha-synuclein mutation. J Neurol Sci 2008; 267:120-4. [DOI: 10.1016/j.jns.2007.10.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 09/26/2007] [Accepted: 10/04/2007] [Indexed: 01/01/2023]
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26
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Di Napoli M, Shah IM, Stewart DA. Molecular pathways and genetic aspects of Parkinson's disease: from bench to bedside. Expert Rev Neurother 2008; 7:1693-729. [PMID: 18052765 DOI: 10.1586/14737175.7.12.1693] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Idiopathic Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by dopaminergic neuronal loss within the substantia nigra. The incidence and prevalence of PD is rising with an increasing aging population. PD is a slowly progressive condition and patients can develop debilitating motor and functional impairment. Current research has implicated oxidative stress, alpha-synucleinopathy and dysfunction of the ubiquitin-proteasome system in the pathogenesis of PD. A number of gene mutations have also been linked to the development of PD. The elucidation of these new molecular pathways has increased our knowledge of PD pathophysiology. This article reviews important molecular mechanisms and genetic causes implicated in the pathogenesis of PD, which has led to new areas of therapeutic drug research.
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Affiliation(s)
- Mario Di Napoli
- Neurological Service, San Camillo de'Lellis General Hospital, I-2100 Rieti, Italy.
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