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Maran JJ, Adesina MM, Green CR, Kwakowsky A, Mugisho OO. The central role of the NLRP3 inflammasome pathway in the pathogenesis of age-related diseases in the eye and the brain. Ageing Res Rev 2023; 88:101954. [PMID: 37187367 DOI: 10.1016/j.arr.2023.101954] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/08/2023] [Accepted: 05/12/2023] [Indexed: 05/17/2023]
Abstract
With increasing age, structural changes occur in the eye and brain. Neuronal death, inflammation, vascular disruption, and microglial activation are among many of the pathological changes that can occur during ageing. Furthermore, ageing individuals are at increased risk of developing neurodegenerative diseases in these organs, including Alzheimer's disease (AD), Parkinson's disease (PD), glaucoma and age-related macular degeneration (AMD). Although these diseases pose a significant global public health burden, current treatment options focus on slowing disease progression and symptomatic control rather than targeting underlying causes. Interestingly, recent investigations have proposed an analogous aetiology between age-related diseases in the eye and brain, where a process of chronic low-grade inflammation is implicated. Studies have suggested that patients with AD or PD are also associated with an increased risk of AMD, glaucoma, and cataracts. Moreover, pathognomonic amyloid-β and α-synuclein aggregates, which accumulate in AD and PD, respectively, can be found in ocular parenchyma. In terms of a common molecular pathway that underpins these diseases, the nucleotide-binding domain, leucine-rich-containing family, and pyrin domain-containing-3 (NLRP3) inflammasome is thought to play a vital role in the manifestation of all these diseases. This review summarises the current evidence regarding cellular and molecular changes in the brain and eye with age, similarities between ocular and cerebral age-related diseases, and the role of the NLRP3 inflammasome as a critical mediator of disease propagation in the eye and the brain during ageing.
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Affiliation(s)
- Jack J Maran
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Moradeke M Adesina
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology and the New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Andrea Kwakowsky
- Pharmacology and Therapeutics, School of Medicine, Galway Neuroscience Centre, University of Galway, Galway, Ireland
| | - Odunayo O Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand.
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Voronkov DN, Stavrovskaya AV, Potapov IA, Guschina AS, Olshanskiy AS. Glial Reaction in a Neuroinflammatory Model of Parkinson's Disease. Bull Exp Biol Med 2023; 174:693-698. [PMID: 37043065 DOI: 10.1007/s10517-023-05772-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Indexed: 04/13/2023]
Abstract
Sixty and 90 days after unilateral intranigral injection of LPS to Wistar rats (10 μg), activation of microglia, neuronal death, and formation of synuclein-positive inclusions were observed in the substantia nigra, but not in dopaminergic neurons. Astrocytes were characterized by increased expression of gliofibrillary protein GFAP, vimentin, complement protein C3, aquaporin-4, and connexin-43. At later stages, GFAP expression decreased, but the distribution of aquaporin-4 and connexin-43 remained disordered, and neuronal degeneration deteriorated. Thus, reactive changes in astrocytes after LPS administration can cause long-term disturbances of the neurogliovascular coupling. The observed functional and morphological alterations in the astroglia can be the cause of progressive disturbances in the substantia nigra.
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Affiliation(s)
| | | | - I A Potapov
- Research Center of Neurology, Moscow, Russia
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Prunell G, Olivera-Bravo S. A Focus on Astrocyte Contribution to Parkinson's Disease Etiology. Biomolecules 2022; 12:biom12121745. [PMID: 36551173 PMCID: PMC9775515 DOI: 10.3390/biom12121745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/17/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Parkinson's disease (PD) is an incurable neurodegenerative disease of high prevalence, characterized by the prominent death of dopaminergic neurons in the substantia nigra pars compacta, which produces dopamine deficiency, leading to classic motor symptoms. Although PD has traditionally been considered as a neuronal cell autonomous pathology, in which the damage of vulnerable neurons is responsible for the disease, growing evidence strongly suggests that astrocytes might have an active role in the neurodegeneration observed. In the present review, we discuss several studies evidencing astrocyte implications in PD, highlighting the consequences of both the loss of normal homeostatic functions and the gain in toxic functions for the wellbeing of dopaminergic neurons. The revised information provides significant evidence that allows astrocytes to be positioned as crucial players in PD etiology, a factor that needs to be taken into account when considering therapeutic targets for the treatment of the disease.
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Affiliation(s)
- Giselle Prunell
- Laboratorio de Neurodegeneración y Neuroprotección, Departamento de Neuroquímica, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, Montevideo 11600, Uruguay
- Correspondence: (G.P.); (S.O.-B.); Tel.: +598-24871616 (ext. 121 or 123 or 171) (G.P. & S.O.-B.)
| | - Silvia Olivera-Bravo
- Laboratorio de Neurobiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, Montevideo 11600, Uruguay
- Correspondence: (G.P.); (S.O.-B.); Tel.: +598-24871616 (ext. 121 or 123 or 171) (G.P. & S.O.-B.)
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权 会, 徐 卫, 祁 宇, 李 清, 周 辉, 黄 婧. [Inhibition connexin 43 by mimetic peptide Gap27 mediates protective effects on 6-hydroxydopamine induced Parkinson's disease mouse model]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2022; 54:421-426. [PMID: 35701117 PMCID: PMC9197703 DOI: 10.19723/j.issn.1671-167x.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To explore whether the using of mimetic peptide Gap27, a selective inhibitor of connexin 43 (Cx43), could block the death of dopamine neurons and influence the expression of Cx43 in 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease mouse models. METHODS Eighteen C57BL/6 mice were randomly divided into control group, 6-OHDA group and 6-OHDA+Gap27 group, with 6 mice in each group. Bilateral substantia nigra stereotactic injection was performed. The control group was injected with ascorbate solution, 6-OHDA group was injected with 6-OHDA solution, and 6-OHDA+Gap27 group was injected with 6-OHDA and Gap27 mixed solution. Immuno-histochemical staining was used to detect the number of dopamine neurons, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of Cx43 messenger ribonucleic acid (mRNA), immuno-fluorescence staining was used to detect the distribution of Cx43 protein, the contents of Cx43 protein and Cx43 phosphorylation at serine 368 (Cx43-ps368) in mouse midbrain were detected by Western blot. RESULTS After injection of 6-OHDA, numerous dopamine neurons in substantia nigra died as Cx43 content increased, Cx43-ps368 content decreased. Mixing Gap27 while injecting 6-OHDA could reduce the number of death dopamine neurons and weaken the changes of Cx43 and Cx43-ps368 content caused by 6-OHDA. The number of tyrosine hydroxylase (TH) immunoreactive positive neurons in 6-OHDA group decreased to 27.7% ± 0.02% of the control group (P < 0.01); The number of TH immunoreactive positive neurons in 6-OHDA+Gap27 group was (1.64±0.16) times higher than that in 6-OHDA group (P < 0.05); The content of total Cx43 protein in 6-OHDA group was (1.44±0.07) times higher than that in 6-OHDA+Gap27 group (P < 0.05) while (1.68±0.07) times higher than that in control group (P < 0.01). In 6-OHDA group, the content of Cx43-ps368 protein and its proportion in total Cx43 protein were significantly lower than that in 6-OHDA+Gap27 group (P < 0.05). CONCLUSION In 6-OHDA mouse models, mimetic peptide Gap27 played a protective role in reducing the damage to substantia nigra dopamine neurons, which was induced by 6-OHDA. The overexpression of Cx43 protein might have neurotoxicity to dopamine neuron. Meanwhile, decreasing Cx43 protein level and keeping Cx43-ps368 protein level may be the protective mechanisms of Gap27.
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Affiliation(s)
- 会会 权
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 卫星 徐
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 宇泽 祁
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 清如 李
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 辉 周
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 婧 黄
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
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Tokunaga N, Takimoto T, Nakamura Y, Hisaoka-Nakashima K, Morioka N. Downregulation of connexin 43 potentiates amitriptyline-induced brain-derived neurotrophic factor expression in primary astrocytes through lysophosphatidic acid receptor 1/3, Src, and extracellular signal-regulated kinase. Eur J Pharmacol 2022; 925:174986. [PMID: 35490723 DOI: 10.1016/j.ejphar.2022.174986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 01/07/2023]
Abstract
Connexin 43 (Cx43) expression is decreased in the prefrontal cortex of patients with depression, but its significance is still unknown. Neurotrophic factors, such as brain-derived neurotrophic factor (BDNF), are involved in the effects of antidepressant. However, the relationship between Cx43 expression and induction of brain-derived neurotrophic factor production by antidepressants is unknown. On the basis of our previous study, which showed that adrenergic receptors stimulation results in potentiation of BDNF expression in astrocytes with downregulated Cx43 expression, we investigated the induction of BDNF expression by amitriptyline, a tricyclic antidepressant, in Cx43-knockdown astrocytes. Amitriptyline treatment potentiated BDNF expression in Cx43-knockdown astrocytes compared with those treated with non-targeting small interfering RNA (siRNA). Using a pharmacological approach, we revealed that the potentiating effect of amitriptyline on BDNF expression was mediated by lysophosphatidic acid (LPA) receptor1/3 (LPA1/3) stimulation and subsequent activation of Src-extracellular signal-regulated kinase (ERK) signaling. These findings suggest that downregulation of Cx43 in patients with depression might contribute to the therapeutic efficacy of antidepressants rather than the pathogenesis of depression.
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Affiliation(s)
- Nozomi Tokunaga
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima, 734-8553, Japan
| | - Tomoyo Takimoto
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima, 734-8553, Japan
| | - Yoki Nakamura
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima, 734-8553, Japan
| | - Kazue Hisaoka-Nakashima
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima, 734-8553, Japan
| | - Norimitsu Morioka
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima, 734-8553, Japan.
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Satarker S, Bojja SL, Gurram PC, Mudgal J, Arora D, Nampoothiri M. Astrocytic Glutamatergic Transmission and Its Implications in Neurodegenerative Disorders. Cells 2022; 11:cells11071139. [PMID: 35406702 PMCID: PMC8997779 DOI: 10.3390/cells11071139] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/12/2022] [Accepted: 03/13/2022] [Indexed: 12/11/2022] Open
Abstract
Several neurodegenerative disorders involve impaired neurotransmission, and glutamatergic neurotransmission sets a prototypical example. Glutamate is a predominant excitatory neurotransmitter where the astrocytes play a pivotal role in maintaining the extracellular levels through release and uptake mechanisms. Astrocytes modulate calcium-mediated excitability and release several neurotransmitters and neuromodulators, including glutamate, and significantly modulate neurotransmission. Accumulating evidence supports the concept of excitotoxicity caused by astrocytic glutamatergic release in pathological conditions. Thus, the current review highlights different vesicular and non-vesicular mechanisms of astrocytic glutamate release and their implication in neurodegenerative diseases. As in presynaptic neurons, the vesicular release of astrocytic glutamate is also primarily meditated by calcium-mediated exocytosis. V-ATPase is crucial in the acidification and maintenance of the gradient that facilitates the vesicular storage of glutamate. Along with these, several other components, such as cystine/glutamate antiporter, hemichannels, BEST-1, TREK-1, purinergic receptors and so forth, also contribute to glutamate release under physiological and pathological conditions. Events of hampered glutamate uptake could promote inflamed astrocytes to trigger repetitive release of glutamate. This could be favorable towards the development and worsening of neurodegenerative diseases. Therefore, across neurodegenerative diseases, we review the relations between defective glutamatergic signaling and astrocytic vesicular and non-vesicular events in glutamate homeostasis. The optimum regulation of astrocytic glutamatergic transmission could pave the way for the management of these diseases and add to their therapeutic value.
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Affiliation(s)
- Sairaj Satarker
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India; (S.S.); (S.L.B.); (P.C.G.); (J.M.)
| | - Sree Lalitha Bojja
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India; (S.S.); (S.L.B.); (P.C.G.); (J.M.)
| | - Prasada Chowdari Gurram
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India; (S.S.); (S.L.B.); (P.C.G.); (J.M.)
| | - Jayesh Mudgal
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India; (S.S.); (S.L.B.); (P.C.G.); (J.M.)
| | - Devinder Arora
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India; (S.S.); (S.L.B.); (P.C.G.); (J.M.)
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, QLD 4222, Australia;
| | - Madhavan Nampoothiri
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, India; (S.S.); (S.L.B.); (P.C.G.); (J.M.)
- Correspondence:
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7
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Yu W, Jin H, Sun W, Nan D, Deng J, Jia J, Yu Z, Huang Y. Connexin43 promotes angiogenesis through activating the HIF-1α/VEGF signaling pathway under chronic cerebral hypoperfusion. J Cereb Blood Flow Metab 2021; 41:2656-2675. [PMID: 33899559 PMCID: PMC8504949 DOI: 10.1177/0271678x211010354] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Chronic cerebral hypoperfusion, a major vascular contributor to vascular cognitive impairment and dementia, can exacerbate small vessel pathology. Connexin43, the most abundant gap junction protein in brain tissue, has been found to be critically involved in the pathological changes of vascular cognitive impairment and dementia caused by chronic cerebral hypoperfusion. However, the precise mechanisms underpinning its role are unclear. We established a mouse model via bilateral common carotid arteries stenosis on connexin43 heterozygous male mice and demonstrated that connexin43 improves brain blood flow recovery by mediating reparative angiogenesis under chronic cerebral hypoperfusion, which subsequently reduces the characteristic pathologies of vascular cognitive impairment and dementia including white matter lesions and irreversible neuronal injury. We additionally found that connexin43 mediates hypoxia inducible factor-1α expression and then activates the PKA signaling pathway to regulate vascular endothelial growth factor-induced angiogenesis. All the above findings were replicated in bEnd.3 cells treated with 375 µM CoCl2in vitro. These results suggest that connexin 43 could be instrumental in developing potential therapies for vascular cognitive impairment and dementia caused by chronic cerebral hypoperfusion.
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Affiliation(s)
- Weiwei Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Haiqiang Jin
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Wei Sun
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Ding Nan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Jianwen Deng
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Jingjing Jia
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zemou Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yining Huang
- Department of Neurology, Peking University First Hospital, Beijing, China
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Ling ZM, Wang Q, Ma Y, Xue P, Gu Y, Cao MH, Wei ZY. Astrocyte Pannexin 1 Suppresses LPS-Induced Inflammatory Responses to Protect Neuronal SH-SY5Y Cells. Front Cell Neurosci 2021; 15:710820. [PMID: 34475813 PMCID: PMC8406772 DOI: 10.3389/fncel.2021.710820] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/16/2021] [Indexed: 01/05/2023] Open
Abstract
Reactive astrogliosis is a key hallmark of inflammatory responses in the pathogenesis of brain injury, including Parkinson’s disease (PD), but its role and regulatory mechanisms are not fully understood. Pannexin 1 (Panx 1) is a membrane channel that mediates substance release in many neurodegenerative diseases. However, the role of astrocyte Panx 1 in the regulation of PD-like neuroinflammation remains elusive. Here, we characterized the expression of Panx 1 in isolated primary astrocytes and a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model. The functions of Panx 1 in inflammatory cytokines expression and the viability of neuronal SH-SY5Y cells were examined in cultured cells treated with lipopolysaccharide (LPS) and 1-methyl-4-phenylpyridinium (MPP+). We found that Panx 1 expression was significantly increased under both LPS- and MPP+-treated conditions. Panx 1 downregulation suppressed LPS-induced pro-inflammatory cytokine expression but did not significantly affect MPP+-induced astrocyte apoptosis or inflammatory cytokine expression through treatment with the Panx 1 inhibitor carbenoxolone (CBX) and Panx 1 siRNA. Moreover, silencing Panx 1 in reactive astrocytes had a potentially protective effect on the viability of neuronal SH-SY5Y cells. Therefore, we propose that Panx 1 may serve as a key regulator in reactive astrocytes to intervene in the inflammatory response and maintain neuronal viability in the context of PD-like conditions.
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Affiliation(s)
- Zhuo-Min Ling
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Medical School of Nantong University, Nantong, China
| | - Qian Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yu Ma
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Peng Xue
- Medical School of Nantong University, Nantong, China
| | - Yun Gu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Mao-Hong Cao
- Medical School of Nantong University, Nantong, China.,Department of Neurology, Affiliated Hospital of Nantong University, Nantong, China
| | - Zhong-Ya Wei
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
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Novel Approaches Used to Examine and Control Neurogenesis in Parkinson's Disease. Int J Mol Sci 2021; 22:ijms22179608. [PMID: 34502516 PMCID: PMC8431772 DOI: 10.3390/ijms22179608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 12/16/2022] Open
Abstract
Neurogenesis is a key mechanism of brain development and plasticity, which is impaired in chronic neurodegeneration, including Parkinson’s disease. The accumulation of aberrant α-synuclein is one of the features of PD. Being secreted, this protein produces a prominent neurotoxic effect, alters synaptic plasticity, deregulates intercellular communication, and supports the development of neuroinflammation, thereby providing propagation of pathological events leading to the establishment of a PD-specific phenotype. Multidirectional and ambiguous effects of α-synuclein on adult neurogenesis suggest that impaired neurogenesis should be considered as a target for the prevention of cell loss and restoration of neurological functions. Thus, stimulation of endogenous neurogenesis or cell-replacement therapy with stem cell-derived differentiated neurons raises new hopes for the development of effective and safe technologies for treating PD neurodegeneration. Given the rapid development of optogenetics, it is not surprising that this method has already been repeatedly tested in manipulating neurogenesis in vivo and in vitro via targeting stem or progenitor cells. However, niche astrocytes could also serve as promising candidates for controlling neuronal differentiation and improving the functional integration of newly formed neurons within the brain tissue. In this review, we mainly focus on current approaches to assess neurogenesis and prospects in the application of optogenetic protocols to restore the neurogenesis in Parkinson’s disease.
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Huang X, Su Y, Wang N, Li H, Li Z, Yin G, Chen H, Niu J, Yi C. Astroglial Connexins in Neurodegenerative Diseases. Front Mol Neurosci 2021; 14:657514. [PMID: 34122008 PMCID: PMC8192976 DOI: 10.3389/fnmol.2021.657514] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 05/05/2021] [Indexed: 12/16/2022] Open
Abstract
Astrocytes play a crucial role in the maintenance of the normal functions of the Central Nervous System (CNS). During the pathogenesis of neurodegenerative diseases, astrocytes undergo morphological and functional remodeling, a process called reactive astrogliosis, in response to the insults to the CNS. One of the key aspects of the reactive astrocytes is the change in the expression and function of connexins. Connexins are channel proteins that highly expressed in astrocytes, forming gap junction channels and hemichannels, allowing diffusional trafficking of small molecules. Alterations of astrocytic connexin expression and function found in neurodegenerative diseases have been shown to affect the disease progression by changing neuronal function and survival. In this review, we will summarize the role of astroglial connexins in neurodegenerative diseases including Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Also, we will discuss why targeting connexins can be a plausible therapeutic strategy to manage these neurodegenerative diseases.
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Affiliation(s)
- Xiaomin Huang
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Yixun Su
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Nan Wang
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Hui Li
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Zhigang Li
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Guowei Yin
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Hui Chen
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Jianqin Niu
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Chenju Yi
- Research Centre, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
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Charvériat M, Mouthon F, Rein W, Verkhratsky A. Connexins as therapeutic targets in neurological and neuropsychiatric disorders. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166098. [PMID: 33545299 DOI: 10.1016/j.bbadis.2021.166098] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/06/2021] [Accepted: 01/19/2021] [Indexed: 12/16/2022]
Abstract
Astrocytes represent the reticular part of the central nervous system; gap junctions formed by connexins Cx43, Cx30- and Cx26 provide for homocellular astrocyte-astrocyte coupling, whereas connexins Cx30, Cx32, Cx43, and Cx47 connect astrocytes and oligodendrocytes. Astroglial networks are anatomically and functionally segregated being homologous to neuronal ensembles. Connexons, gap junctions and hemichannels (unpaired connexons) are affected in various neuropathologies from neuropsychiatric to neurodegenerative diseases. Manipulation of astrocytic connexins modulates the size and outreach of astroglial syncytia thus affecting astroglial homeostatic support. Modulation of astrocytic connexin significantly modifies pharmacological profile of many CNS drugs, which represents an innovative therapeutic approach for CNS disorders; this approach is now actively tested in pre-clinical and clinical studies. Wide combination of connexin modulators with CNS drugs open new promising perspectives for fundamental studies and therapeutic strategies.
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Affiliation(s)
| | | | | | - A Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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Mesnil M, Defamie N, Naus C, Sarrouilhe D. Brain Disorders and Chemical Pollutants: A Gap Junction Link? Biomolecules 2020; 11:biom11010051. [PMID: 33396565 PMCID: PMC7824109 DOI: 10.3390/biom11010051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.
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Affiliation(s)
- Marc Mesnil
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Norah Defamie
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Christian Naus
- Faculty of Medicine, Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
| | - Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculté de Médecine et Pharmacie, 6 rue de La Milétrie, bât D1, TSA 51115, 86073 Poitiers, France
- Correspondence: ; Tel.: +33-5-49-45-43-58
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13
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Giaume C, Naus CC, Sáez JC, Leybaert L. Glial Connexins and Pannexins in the Healthy and Diseased Brain. Physiol Rev 2020; 101:93-145. [PMID: 32326824 DOI: 10.1152/physrev.00043.2018] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Over the past several decades a large amount of data have established that glial cells, the main cell population in the brain, dynamically interact with neurons and thus impact their activity and survival. One typical feature of glia is their marked expression of several connexins, the membrane proteins forming intercellular gap junction channels and hemichannels. Pannexins, which have a tetraspan membrane topology as connexins, are also detected in glial cells. Here, we review the evidence that connexin and pannexin channels are actively involved in dynamic and metabolic neuroglial interactions in physiological as well as in pathological situations. These features of neuroglial interactions open the way to identify novel non-neuronal aspects that allow for a better understanding of behavior and information processing performed by neurons. This will also complement the "neurocentric" view by facilitating the development of glia-targeted therapeutic strategies in brain disease.
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Affiliation(s)
- Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Christian C Naus
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Juan C Sáez
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Luc Leybaert
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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Sánchez OF, Rodríguez AV, Velasco-España JM, Murillo LC, Sutachan JJ, Albarracin SL. Role of Connexins 30, 36, and 43 in Brain Tumors, Neurodegenerative Diseases, and Neuroprotection. Cells 2020; 9:E846. [PMID: 32244528 PMCID: PMC7226843 DOI: 10.3390/cells9040846] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/15/2020] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
Gap junction (GJ) channels and their connexins (Cxs) are complex proteins that have essential functions in cell communication processes in the central nervous system (CNS). Neurons, astrocytes, oligodendrocytes, and microglial cells express an extraordinary repertory of Cxs that are important for cell to cell communication and diffusion of metabolites, ions, neurotransmitters, and gliotransmitters. GJs and Cxs not only contribute to the normal function of the CNS but also the pathological progress of several diseases, such as cancer and neurodegenerative diseases. Besides, they have important roles in mediating neuroprotection by internal or external molecules. However, regulation of Cx expression by epigenetic mechanisms has not been fully elucidated. In this review, we provide an overview of the known mechanisms that regulate the expression of the most abundant Cxs in the central nervous system, Cx30, Cx36, and Cx43, and their role in brain cancer, CNS disorders, and neuroprotection. Initially, we focus on describing the Cx gene structure and how this is regulated by epigenetic mechanisms. Then, the posttranslational modifications that mediate the activity and stability of Cxs are reviewed. Finally, the role of GJs and Cxs in glioblastoma, Alzheimer's, Parkinson's, and Huntington's diseases, and neuroprotection are analyzed with the aim of shedding light in the possibility of using Cx regulators as potential therapeutic molecules.
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Affiliation(s)
- Oscar F. Sánchez
- Department of Nutrition and Biochemistry, Pontificia Universidad Javeriana, 110911 Bogota, Colombia; (A.V.R.); (J.M.V.-E.); (L.C.M.); (J.-J.S.)
| | | | | | | | | | - Sonia-Luz Albarracin
- Department of Nutrition and Biochemistry, Pontificia Universidad Javeriana, 110911 Bogota, Colombia; (A.V.R.); (J.M.V.-E.); (L.C.M.); (J.-J.S.)
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15
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Kim HJ, Kim MJ, Mostafa MN, Park JH, Choi HS, Kim YS, Choi EK. RhoA/ROCK Regulates Prion Pathogenesis by Controlling Connexin 43 Activity. Int J Mol Sci 2020; 21:ijms21041255. [PMID: 32070020 PMCID: PMC7072953 DOI: 10.3390/ijms21041255] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 11/16/2022] Open
Abstract
Scrapie infection, which converts cellular prion protein (PrPC) into the pathological and infectious isoform (PrPSc), leads to neuronal cell death, glial cell activation and PrPSc accumulation. Previous studies reported that PrPC regulates RhoA/Rho-associated kinase (ROCK) signaling and that connexin 43 (Cx43) expression is upregulated in in vitro and in vivo prion-infected models. However, whether there is a link between RhoA/ROCK and Cx43 in prion disease pathogenesis is uncertain. Here, we investigated the role of RhoA/ROCK signaling and Cx43 in prion diseases using in vitro and in vivo models. Scrapie infection induced RhoA activation, accompanied by increased phosphorylation of LIM kinase 1/2 (LIMK1/2) at Thr508/Thr505 and cofilin at Ser3 and reduced phosphorylation of RhoA at Ser188 in hippocampal neuronal cells and brains of mice. Scrapie infection-induced RhoA activation also resulted in PrPSc accumulation followed by a reduction in the interaction between RhoA and p190RhoGAP (a GTPase-activating protein). Interestingly, scrapie infection significantly enhanced the interaction between RhoA and Cx43. Moreover, RhoA and Cx43 colocalization was more visible in both the membrane and cytoplasm of scrapie-infected hippocampal neuronal cells than in controls. Finally, RhoA and ROCK inhibition reduced PrPSc accumulation and the RhoA/Cx43 interaction, leading to decreased Cx43 hemichannel activity in scrapie-infected hippocampal neuronal cells. These findings suggest that RhoA/ROCK regulates Cx43 activity, which may have an important role in the pathogenesis of prion disease.
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Affiliation(s)
- Hee-Jun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do 14066, Korea; (H.-J.K.); (M.-J.K.); (M.N.M.); (J.-H.P.); (H.-S.C.); (Y.-S.K.)
| | - Mo-Jong Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do 14066, Korea; (H.-J.K.); (M.-J.K.); (M.N.M.); (J.-H.P.); (H.-S.C.); (Y.-S.K.)
- Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do 24252, Korea
| | - Mohd Najib Mostafa
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do 14066, Korea; (H.-J.K.); (M.-J.K.); (M.N.M.); (J.-H.P.); (H.-S.C.); (Y.-S.K.)
- Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do 24252, Korea
| | - Jeong-Ho Park
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do 14066, Korea; (H.-J.K.); (M.-J.K.); (M.N.M.); (J.-H.P.); (H.-S.C.); (Y.-S.K.)
| | - Hong-Seok Choi
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do 14066, Korea; (H.-J.K.); (M.-J.K.); (M.N.M.); (J.-H.P.); (H.-S.C.); (Y.-S.K.)
| | - Yong-Sun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do 14066, Korea; (H.-J.K.); (M.-J.K.); (M.N.M.); (J.-H.P.); (H.-S.C.); (Y.-S.K.)
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Gangwon-do 24252, Korea
| | - Eun-Kyoung Choi
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do 14066, Korea; (H.-J.K.); (M.-J.K.); (M.N.M.); (J.-H.P.); (H.-S.C.); (Y.-S.K.)
- Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do 24252, Korea
- Correspondence: ; Tel.: +82-31-380-1893; Fax: +82-31-388-3427
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16
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Eftekhari A, Vahed SZ, Kavetskyy T, Rameshrad M, Jafari S, Chodari L, Hosseiniyan SM, Derakhshankhah H, Ahmadian E, Ardalan M. Cell junction proteins: Crossing the glomerular filtration barrier in diabetic nephropathy. Int J Biol Macromol 2020; 148:475-482. [PMID: 31962072 DOI: 10.1016/j.ijbiomac.2020.01.168] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/17/2020] [Accepted: 01/17/2020] [Indexed: 12/20/2022]
Abstract
Diabetic nephropathy as a deleterious complication of diabetes mellitus and an important cause of end-stage renal failure is characterized by changes in the molecular and cellular levels. Cell-cell communication via the gap and tight junctions are involved in the pathogenesis of diseases such as diabetes and kidney failure. Studying cell junctions including gap junctions, tight junctions, and anchoring junctions within the nephron can be used as an early sign of diabetic nephropathy. Furthermore, cell junctions may be an upcoming target by pharmacological methods to improve treatments of diabetic nephropathy and pave the way to introduce promising therapeutic strategies based on cell-cell communications effects and its translation into clinical studies for the treatment of diabetic nephropathy.
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Affiliation(s)
- Aziz Eftekhari
- Pharmacology and Toxicology Department, Maragheh University of Medical Sciences, Maragheh, Iran
| | | | - Taras Kavetskyy
- Drohobych Ivan Franko State Pedagogical University, Drohobych, Ukraine; The John Paul II Catholic University of Lublin, Lublin, Poland
| | - Maryam Rameshrad
- Natural Products and Medicinal Plants Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Samira Jafari
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Leila Chodari
- Physiology Department, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | | | - Hossein Derakhshankhah
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Elham Ahmadian
- Kidney Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Students Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
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17
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Glia-neuron interactions underlie state transitions to generalized seizures. Nat Commun 2019; 10:3830. [PMID: 31444362 PMCID: PMC6707163 DOI: 10.1038/s41467-019-11739-z] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 07/31/2019] [Indexed: 11/08/2022] Open
Abstract
Brain activity and connectivity alter drastically during epileptic seizures. The brain networks shift from a balanced resting state to a hyperactive and hypersynchronous state. It is, however, less clear which mechanisms underlie the state transitions. By studying neural and glial activity in zebrafish models of epileptic seizures, we observe striking differences between these networks. During the preictal period, neurons display a small increase in synchronous activity only locally, while the gap-junction-coupled glial network was highly active and strongly synchronized across large distances. The transition from a preictal state to a generalized seizure leads to an abrupt increase in neural activity and connectivity, which is accompanied by a strong alteration in glia-neuron interactions and a massive increase in extracellular glutamate. Optogenetic activation of glia excites nearby neurons through the action of glutamate and gap junctions, emphasizing a potential role for glia-glia and glia-neuron connections in the generation of epileptic seizures. During epileptic seizures, neural activity across the brain switches into a hyperactive and hypersynchronized state. Here, the authors report on the role of glia-glia and glia-neuron interactions in mediating the changes that result in the ictal state in a zebrafish model of epilepsy.
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18
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Xie Z, Yang Q, Song D, Quan Z, Qing H. Optogenetic manipulation of astrocytes from synapses to neuronal networks: A potential therapeutic strategy for neurodegenerative diseases. Glia 2019; 68:215-226. [PMID: 31400164 DOI: 10.1002/glia.23693] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 02/06/2023]
Abstract
Astrocytes are the most widespread and heterogeneous glial cells in the central nervous system and key regulators for brain development. They are capable of receiving neurotransmitters produced by synaptic activities and regulating synaptic functions by releasing gliotransmitters as part of the tripartite synapse. In addition to communicating with neurons at synaptic levels, astrocytes can integrate into inhibitory neural networks to interact with neurons in neuronal circuits. Astrocytes are closely related to the pathogenesis and pathological processes of neurodegenerative diseases (NDs). Recently, optogenetics has now been applied to reveal the function of astrocytes in physiology and pathology. Herein, we discuss the possibility whether optogenetics could be used to control the release of gliotransmitters and regulate astrocytic membrane channels. Thus, the capability of modulating the bidirectional interactions between astrocytes and neurons in both synaptic and neuronal networks via optogenetics is evaluated. Furthermore, we discuss that manipulating astrocytes via optogenetics might be an effective way to investigate the potential therapeutic strategy for NDs.
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Affiliation(s)
- Zhen Xie
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - Qinghu Yang
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Sciences, Beijing Institute of Technology, Beijing, China.,College of Life Sciences & Research Center for Resource Peptide Drugs, Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, Yanan University, Yanan, China
| | - Da Song
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Sciences, Beijing Institute of Technology, Beijing, China
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19
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Halpern M, Brennand KJ, Gregory J. Examining the relationship between astrocyte dysfunction and neurodegeneration in ALS using hiPSCs. Neurobiol Dis 2019; 132:104562. [PMID: 31381978 DOI: 10.1016/j.nbd.2019.104562] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 06/28/2019] [Accepted: 07/31/2019] [Indexed: 02/07/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a complex and fatal neurodegenerative disease for which the causes of disease onset and progression remain unclear. Recent advances in human induced pluripotent stem cell (hiPSC)-based models permit the study of the genetic factors associated with ALS in patient-derived neural cell types, including motor neurons and glia. While astrocyte dysfunction has traditionally been thought to exacerbate disease progression, astrocytic dysfunction may play a more direct role in disease initiation and progression. Such non-cell autonomous mechanisms expand the potential targets of therapeutic intervention, but only a handful of ALS risk-associated genes have been examined for their impact on astrocyte dysfunction and neurodegeneration. This review summarizes what is currently known about astrocyte function in ALS and suggests ways in which hiPSC-based models can be used to more effectively study the role of astrocytes in neurodegenerative disease.
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Affiliation(s)
- Madeline Halpern
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America
| | - Kristen J Brennand
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America.
| | - James Gregory
- Center for Genomics of Neurodegenerative Disease, New York Genome Center, New York, NY 10013, United States of America.
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20
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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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Mattii L, Pardini C, Ippolito C, Bianchi F, Sabbatini ARM, Vaglini F. Rho-inhibition and neuroprotective effect on rotenone-treated dopaminergic neurons in vitro. Neurotoxicology 2019; 72:51-60. [PMID: 30769001 DOI: 10.1016/j.neuro.2019.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 10/27/2022]
Abstract
Mesencephalic cell cultures are a good model to study the vulnerability of dopaminergic neurons and reproduce, in vitro, experimental models of Parkinson's disease. Rotenone associated as an environmental neurotoxin related to PD, is able to provoke dopaminergic neuron degeneration by inhibiting complex I of the mitochondrial respiratory chain and by inducing accumulation of α-synuclein. Recently, rotenone has been described to activate RhoA, a GTPase protein. In the present study we evaluated a possible neuroprotective effect of Rho-inhibitor molecules on rotenone-damaged dopaminergic (DA) neurons obtained from mouse primary mesencephalic cell culture. Our results showed that Clostridium Botulinum C3 toxin (C3) and simvastatin, as RhoA inhibitors, were able to protect DA neurons from rotenone damages. In fact, pretreatment with C3 or simvastatin significantly prevented the reduction of [3H]dopamine uptake, neurites injury and the expression patterns of proteins like α-syn, actin and connexin 43.
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Affiliation(s)
- Letizia Mattii
- Department of Clinical and Experimental Medicine, Unit of Histology, via Roma 55, University of Pisa, 56126 Pisa, Italy; Interdepartmental Research Center Nutraceuticals and Food for Health, University of Pisa, 56124 Pisa, Italy
| | - Carla Pardini
- Department of Translational Research and of New Surgical and Medical Technologies, via Roma 55, University of Pisa, 56126 Pisa, Italy
| | - Chiara Ippolito
- Department of Clinical and Experimental Medicine, Unit of Histology, via Roma 55, University of Pisa, 56126 Pisa, Italy
| | - Francesco Bianchi
- Department of Clinical and Experimental Medicine, Unit of Histology, via Roma 55, University of Pisa, 56126 Pisa, Italy
| | | | - Francesca Vaglini
- Department of Translational Research and of New Surgical and Medical Technologies, via Roma 55, University of Pisa, 56126 Pisa, Italy.
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22
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Wong J, Chopra J, Chiang LLW, Liu T, Ho J, Wu WKK, Tse G, Wong SH. The Role of Connexins in Gastrointestinal Diseases. J Mol Biol 2019; 431:643-652. [PMID: 30639409 DOI: 10.1016/j.jmb.2019.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/03/2018] [Accepted: 01/04/2019] [Indexed: 12/13/2022]
Abstract
Gap junctions are hexagonal arrays of protein molecules in the plasma membrane and were first described in Mauthner cell synapses of goldfish. They form pathways for coupling between cells, allowing passive, electrotonic spread of ions and also passage of larger molecules such as amino acids and nucleotides. They are expressed in both excitable and non-excitable tissues. Each gap junction is made of two connexons, which are hexameric proteins of the connexin subunit. In this review, the roles that connexins play in gastrointestinal motility, the mechanisms of altered connexin expression leading to inflammatory bowel disease, gastrointestinal infections, and gastrointestinal symptoms in autistic spectrum disorder are discussed in detail.
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Affiliation(s)
- Jeremy Wong
- Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, PR China
| | - Jasmine Chopra
- Faculty of Arts and Science, University of Toronto, Toronto, Canada
| | | | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, PR China
| | - Jeffery Ho
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, PR China; Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, PR China
| | - William K K Wu
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, PR China; Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, PR China
| | - Gary Tse
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, PR China; Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, PR China.
| | - Sunny Hei Wong
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, PR China; Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, PR China.
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23
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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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Ren Q, Wang ZZ, Chu SF, Xia CY, Chen NH. Gap junction channels as potential targets for the treatment of major depressive disorder. Psychopharmacology (Berl) 2018; 235:1-12. [PMID: 29178009 DOI: 10.1007/s00213-017-4782-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 11/05/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND Major depressive disorder (MDD) remains a major public health problem worldwide. The association between MDD and the dysfunction of gap junction channels (GJCs) in glial cells, especially astrocytes, is still controversial. OBJECTIVE This review provides an overview of the role of astrocyte GJCs in LMDD. RESULTS Exposure to chronic unpredictable stress caused a reduction in connexin expression in the rat prefrontal cortex, a result that is consistent with clinical findings reported in postmortem studies of brains from MDD patients. Chronic antidepressant treatment in these rats increased the expression of connexins. However, pharmacological GJC blockade in normal rodents decreased connexin expression and caused depressive-like behaviors. Furthermore, GJC dysfunction affects electrical conductance, metabolic coupling and secondary messengers, and inflammatory responses, which are consistent with current hypotheses on MDD. All these results provide a comprehensive overview of the neurobiology of MDD. CONCLUSION This review supports the hypothesis that the regulation of GJCs between astrocytes could be an underlying mechanism for the therapeutic effect of antidepressants.
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Affiliation(s)
- Qian Ren
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Shi-Feng Chu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Cong-Yuan Xia
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China. .,College of Pharmacy, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.
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25
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Gangoso E, Talaverón R, Jaraíz-Rodríguez M, Domínguez-Prieto M, Ezan P, Koulakoff A, Medina JM, Giaume C, Tabernero A. A c-Src Inhibitor Peptide Based on Connexin43 Exerts Neuroprotective Effects through the Inhibition of Glial Hemichannel Activity. Front Mol Neurosci 2017; 10:418. [PMID: 29326548 PMCID: PMC5737028 DOI: 10.3389/fnmol.2017.00418] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 12/01/2017] [Indexed: 12/29/2022] Open
Abstract
The non-receptor tyrosine kinase c-Src is an important mediator in several signaling pathways related to neuroinflammation. Our previous study showed that cortical injection of kainic acid (KA) promoted a transient increase in c-Src activity in reactive astrocytes surrounding the neuronal lesion. As a cell-penetrating peptide based on connexin43 (Cx43), specifically TAT-Cx43266–283, inhibits Src activity, we investigated the effect of TAT-Cx43266–283 on neuronal death promoted by cortical KA injections in adult mice. As expected, KA promoted neuronal death, estimated by the reduction in NeuN-positive cells and reactive gliosis, characterized by the increase in glial fibrillary acidic protein (GFAP) expression. Interestingly, TAT-Cx43266–283 injected with KA diminished neuronal death and reactive gliosis compared to KA or KA+TAT injections. In order to gain insight into the neuroprotective mechanism, we used in vitro models. In primary cultured neurons, TAT-Cx43266–283 did not prevent neuronal death promoted by KA, but when neurons were grown on top of astrocytes, TAT-Cx43266–283 prevented neuronal death promoted by KA. These observations demonstrate the participation of astrocytes in the neuroprotective effect of TAT-Cx43266–283. Furthermore, the neuroprotective effect was also present in non-contact co-cultures, suggesting the contribution of soluble factors released by astrocytes. As glial hemichannel activity is associated with the release of several factors, such as ATP and glutamate, that cause neuronal death, we explored the participation of these channels on the neuroprotective effect of TAT-Cx43266–283. Our results confirmed that inhibitors of ATP and NMDA receptors prevented neuronal death in co-cultures treated with KA, suggesting the participation of astrocyte hemichannels in neurotoxicity. Furthermore, TAT-Cx43266–283 reduced hemichannel activity promoted by KA in neuron-astrocyte co-cultures as assessed by ethidium bromide (EtBr) uptake assay. In fact, TAT-Cx43266–283 and dasatinib, a potent c-Src inhibitor, strongly reduced the activation of astrocyte hemichannels. In conclusion, our results suggest that TAT-Cx43266–283 exerts a neuroprotective effect through the reduction of hemichannel activity likely mediated by c-Src in astrocytes. These data unveil a new role of c-Src in the regulation of Cx43-hemichannel activity that could be part of the mechanism by which astroglial c-Src participates in neuroinflammation.
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Affiliation(s)
- Ester Gangoso
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Rocío Talaverón
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Myriam Jaraíz-Rodríguez
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Marta Domínguez-Prieto
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Pascal Ezan
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Annette Koulakoff
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - José M Medina
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Christian Giaume
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Arantxa Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
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Ginsenoside Rg1-induced antidepressant effects involve the protection of astrocyte gap junctions within the prefrontal cortex. Prog Neuropsychopharmacol Biol Psychiatry 2017; 75:183-191. [PMID: 27876669 DOI: 10.1016/j.pnpbp.2016.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/18/2016] [Accepted: 09/18/2016] [Indexed: 12/15/2022]
Abstract
Ginsenoside Rg1 (Rg1) exhibits antidepressant-like activity by increasing neurogenesis and dendritic spine density without discernible side effects. However, the molecular mechanisms underlying Rg1 antidepressant activity remain poorly understood. As the dysfunction of gap junctions between astrocytes in the prefrontal cortex (PFC) is implicated in major depression disorder, the aim of this study was to investigate the effects of Rg1 on astrocyte gap junctions in the PFC. Rats exposed to chronic unpredictable stress (CUS) were administered Rg1 (5, 10, and 20mg/kg) for 28days and analyzed for depressive symptoms using the sucrose preference and forced swimming tests. Functional and morphological changes of gap junction channels in the PFC were evaluated using dye transfer and electron microscopy, respectively. The expression of connexin 43 (Cx43) was analyzed by western blotting. Rg1 markedly alleviated depression-like behavior in rats. Long-term Rg1 treatment of CUS-exposed rats also significantly prevented the decrease in dye diffusion and improved the ultrastructure of astrocyte gap junctions in the PFC, indicating beneficial effects on the functional activity of gap junction channels in the brain. In addition, Rg1 upregulated Cx43 expression in the PFC reduced by CUS exposure, which significantly correlated with its antidepressant-like effects. The results demonstrate that Rg1-induced antidepressant effects are might be mediated, in part, by protecting astrocyte gap junctions within the prefrontal cortex.
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27
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Schwab BC, van Wezel RJA, van Gils SA. Sparse pallidal connections shape synchrony in a network model of the basal ganglia. Eur J Neurosci 2016; 45:1000-1012. [PMID: 27350120 DOI: 10.1111/ejn.13324] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 01/15/2023]
Abstract
Neural synchrony in the basal ganglia, especially in the beta frequency band (13-30 Hz), is a hallmark of Parkinson's disease and considered as antikinetic. In contrast, the healthy basal ganglia show low levels of synchrony. It is currently unknown where synchrony and oscillations arise in the parkinsonian brain and how they are transmitted through the basal ganglia, as well as what makes them dependent on dopamine. The external part of the globus pallidus has recently been identified as a hub nucleus in the basal ganglia, possessing intrinsic inhibitory connections and possibly also gap junctions. In this study, we show that in a conductance-based network model of the basal ganglia, the combination of sparse, high-conductance inhibitory synapses and sparse, low-conductance gap junctions in the external part of the globus pallidus could effectively desynchronize the whole network. However, when gap junction coupling became strong enough, the effect was impeded and activity synchronized. In particular, sustained periods of beta coherence occurred between some neuron pairs. As gap junctions can change their conductance with the dopamine level, we suggest pallidal gap junction coupling as a mechanism contributing to the development of beta synchrony in the parkinsonian basal ganglia.
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Affiliation(s)
- Bettina C Schwab
- Applied Analysis, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, 7500 AE, Enschede, The Netherlands.,Biomedical Signals and and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, Enschede, The Netherlands
| | - Richard J A van Wezel
- Biomedical Signals and and Systems, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, Enschede, The Netherlands.,Biophysics, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Stephan A van Gils
- Applied Analysis, MIRA Institute of Technical Medicine and Biomedical Technology, University of Twente, 7500 AE, Enschede, The Netherlands
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28
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Abstract
Astrocytes are the most explored non-neuronal cells in the brain under neurophysiological and neurodegenerative conditions. Extensive research has been done to understand their specific role during neuropathological conditions but still the existing findings could not conclude their mechanism of action and their specific role in neurodegenerative conditions. This review discusses their physiological and pathological roles, their activation, morphological alterations and their probable use in search of new therapeutic targets for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Sarika Singh
- a 1 Toxicology Division, CSIR-CDRI , Lucknow , India.,b 2 Department of Biochemistry and Biophysics , University of California , San Francisco, San Francisco , CA , USA
| | - Neeraj Joshi
- a 1 Toxicology Division, CSIR-CDRI , Lucknow , India.,b 2 Department of Biochemistry and Biophysics , University of California , San Francisco, San Francisco , CA , USA
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29
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Jeanson T, Pondaven A, Ezan P, Mouthon F, Charvériat M, Giaume C. Antidepressants Impact Connexin 43 Channel Functions in Astrocytes. Front Cell Neurosci 2016; 9:495. [PMID: 26778961 PMCID: PMC4703821 DOI: 10.3389/fncel.2015.00495] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/09/2015] [Indexed: 12/20/2022] Open
Abstract
Glial cells, and in particular astrocytes, are crucial to maintain neuronal microenvironment by regulating energy metabolism, neurotransmitter uptake, gliotransmission, and synaptic development. Moreover, a typical feature of astrocytes is their high expression level of connexins, a family of membrane proteins that form gap junction channels allowing intercellular exchanges and hemichannels that provide release and uptake pathways for neuroactive molecules. Interestingly, several studies have revealed unexpected changes in astrocytes from depressive patients and rodent models of depressive-like behavior. Moreover, changes in the expression level of the astroglial connexin 43 (Cx43) have been reported in a depressive context. On the other hand, antidepressive drugs have also been shown to impact the expression of this connexin in astrocytes. However, so far there is little information concerning the functional consequence of these changes, i.e., the status of gap junctional communication and hemichannel activity in astrocytes exposed to antidepressants. In the present work we focused our attention on the action of seven antidepressants from four different therapeutic classes and tested their effects on Cx43 expression and on the two connexin-based channels functions studied in cultured astrocytes. We here report that when used at non-toxic and clinically relevant concentrations they have no effects on Cx43 expression but differential effects on Cx43 gap junction channels. Moreover, all tested antidepressants inhibit Cx43 hemichannel with different efficiency depending on their therapeutic classe. By studying the impact of antidepressants on the functional status of astroglial connexin channels, contributing to dynamic neuroglial interactions, our observations should help to better understand the mechanism by which these drugs provide their effect in the brain.
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Affiliation(s)
- Tiffany Jeanson
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France; TheranexusLyon, France
| | - Audrey Pondaven
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| | - Pascal Ezan
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| | | | | | - Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
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30
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Retamal MA, Reyes EP, García IE, Pinto B, Martínez AD, González C. Diseases associated with leaky hemichannels. Front Cell Neurosci 2015; 9:267. [PMID: 26283912 PMCID: PMC4515567 DOI: 10.3389/fncel.2015.00267] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 06/29/2015] [Indexed: 01/10/2023] Open
Abstract
Hemichannels (HCs) and gap junction channels (GJCs) formed by protein subunits called connexins (Cxs) are major pathways for intercellular communication. While HCs connect the intracellular compartment with the extracellular milieu, GJCs allow the interchange of molecules between cytoplasm of two contacting cells. Under physiological conditions, HCs are mostly closed, but they can open under certain stimuli allowing the release of autocrine and paracrine molecules. Moreover, some pathological conditions, like ischemia or other inflammation conditions, significantly increase HCs activity. In addition, some mutations in Cx genes associated with human diseases, such as deafness or cataracts, lead to the formation of more active HCs or “leaky HCs.” In this article we will revise cellular and molecular mechanisms underlying the appearance of leaky HCs, and the consequences of their expression in different cellular systems and animal models, in seeking a common pattern or pathological mechanism of disease.
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Affiliation(s)
- Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Edison P Reyes
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo Santiago, Chile ; Centro de Investigación Biomédica, Universidad Autónoma de Chile Santiago, Chile
| | - Isaac E García
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso Valparaíso, Chile
| | - Bernardo Pinto
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso Valparaíso, Chile
| | - Carlos González
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso Valparaíso, Chile
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31
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Xie HY, Cui Y, Deng F, Feng JC. Connexin: a potential novel target for protecting the central nervous system? Neural Regen Res 2015; 10:659-66. [PMID: 26170830 PMCID: PMC4424762 DOI: 10.4103/1673-5374.155444] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2014] [Indexed: 01/11/2023] Open
Abstract
Connexin subunits are proteins that form gap junction channels, and play an important role in communication between adjacent cells. This review article discusses the function of connexins/hemichannels/gap junctions under physiological conditions, and summarizes the findings regarding the role of connexins/hemichannels/gap junctions in the physiological and pathological mechanisms underlying central nervous system diseases such as brain ischemia, traumatic brain and spinal cord injury, epilepsy, brain and spinal cord tumor, migraine, neuroautoimmune disease, Alzheimer's disease, Parkinson's disease, X-linked Charcot-Marie-Tooth disease, Pelizaeus-Merzbacher-like disease, spastic paraplegia and maxillofacial dysplasia. Connexins are considered to be a potential novel target for protecting the central nervous system.
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Affiliation(s)
- Hong-Yan Xie
- Departmet of Neurology, the First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Yu Cui
- Department of Neurosurgery, the First People's Hospital of Xianyang, Xianyang, Shaanxi Province, China
| | - Fang Deng
- Departmet of Neurology, the First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Jia-Chun Feng
- Departmet of Neurology, the First Hospital of Jilin University, Changchun, Jilin Province, China
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32
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Freitas-Andrade M, Naus CC. Astrocytes in neuroprotection and neurodegeneration: The role of connexin43 and pannexin1. Neuroscience 2015; 323:207-21. [PMID: 25913636 DOI: 10.1016/j.neuroscience.2015.04.035] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 12/26/2022]
Abstract
The World Health Organization has predicted that by 2040 neurodegenerative diseases will overtake cancer to become the world's second leading cause of death after cardiovascular disease. This has sparked the development of several European and American brain research initiatives focusing on elucidating the underlying cellular and molecular mechanisms of neurodegenerative diseases. Connexin (Cx) and pannexin (Panx) membrane channel proteins are conduits through which neuronal, glial, and vascular tissues interact. In the brain, this interaction is highly critical for homeostasis and brain repair after injury. Understanding the molecular mechanisms by which these membrane channels function, in health and disease, might be particularly influential in establishing conceptual frameworks to develop new therapeutics against Cx and Panx channels. This review focuses on current insights and emerging concepts, particularly the impact of connexin43 and pannexin1, under neuroprotective and neurodegenerative conditions within the context of astrocytes.
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Affiliation(s)
- M Freitas-Andrade
- Department of Cellular and Physiological Sciences, The Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - C C Naus
- Department of Cellular and Physiological Sciences, The Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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33
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Phookan S, Sutton AC, Walling I, Smith A, O'Connor KA, Campbell JC, Calos M, Yu W, Pilitsis JG, Brotchie JM, Shin DS. Gap junction blockers attenuate beta oscillations and improve forelimb function in hemiparkinsonian rats. Exp Neurol 2015; 265:160-70. [PMID: 25622779 DOI: 10.1016/j.expneurol.2015.01.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 01/14/2015] [Indexed: 11/25/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative disease characterized by akinesia, bradykinesia, resting tremors and postural instability. Although various models have been developed to explain basal ganglia (BG) pathophysiology in PD, the recent reports that dominant beta (β) oscillations (12-30Hz) in BG nuclei of PD patients and parkinsonian animals coincide with motor dysfunction has led to an emerging idea that these oscillations may be a characteristic of PD. Due to the recent realization of these oscillations, the cellular and network mechanism(s) that underlie this process remain ill-defined. Here, we postulate that gap junctions (GJs) can contribute to β oscillations in the BG of hemiparkinsonian rats and inhibiting their activity will disrupt neuronal synchrony, diminish these oscillations and improve motor function. To test this, we injected the GJ blockers carbenoxolone (CBX) or octanol in the right globus pallidus externa (GPe) of anesthetized hemiparkinsonian rats and noted whether subsequent changes in β oscillatory activity occurred using in vivo electrophysiology. We found that systemic treatment of 200mg/kg CBX attenuated normalized GPe β oscillatory activity from 6.10±1.29 arbitrary units (A.U.) (pre-CBX) to 2.48±0.87 A.U. (post-CBX) with maximal attenuation occurring 90.0±20.5min after injection. The systemic treatment of octanol (350mg/kg) also decreased β oscillatory activity in a similar manner to CBX treatment with β oscillatory activity decreasing from 3.58±0.89 (pre-octanol) to 2.57±1.08 after octanol injection. Next, 1μl CBX (200mg/kg) was directly injected into the GPe of anesthetized hemiparkinsonian rats; 59.2±19.0min after injection, β oscillations in this BG nucleus decreased from 3.62±1.17 A.U. to 1.67±0.62 A.U. Interestingly, we were able to elicit β oscillations in the GPe of naive non-parkinsonian rats by increasing GJ activity with 1μl trimethylamine (TMA, 500nM). Finally, we systemically injected CBX (200mg/kg) into hemiparkinsonian rats which attenuated dominant β oscillations in the right GPe and also improved left forepaw akinesia in the step test. Conversely, direct injection of TMA into the right GPe of naive rats induced contralateral left forelimb akinesia. Overall, our results suggest that GJs contribute to β oscillations in the GPe of hemiparkinsonian rats.
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Affiliation(s)
- Sujoy Phookan
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Alexander C Sutton
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Ian Walling
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Autumn Smith
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Katherine A O'Connor
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Joannalee C Campbell
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Megan Calos
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Wilson Yu
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA
| | - Julie G Pilitsis
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA; Division of Neurosurgery, Albany Medical Center, Albany, NY USA
| | - Jonathan M Brotchie
- Division of Brain Imaging and Behavioral Neuroscience Systems, Toronto Western Research Institute, Toronto Western Hospital, Toronto, ON, Canada
| | - Damian S Shin
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY USA.
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Morioka N, Suekama K, Zhang FF, Kajitani N, Hisaoka-Nakashima K, Takebayashi M, Nakata Y. Amitriptyline up-regulates connexin43-gap junction in rat cultured cortical astrocytes via activation of the p38 and c-Fos/AP-1 signalling pathway. Br J Pharmacol 2014; 171:2854-67. [PMID: 24641259 DOI: 10.1111/bph.12614] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 01/09/2014] [Accepted: 01/25/2014] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Intercellular communication via gap junctions, comprised of connexin (Cx) proteins, allow for communication between astrocytes, which in turn is crucial for maintaining CNS homeostasis. The expression of Cx43 is decreased in post-mortem brains from patients with major depression. A potentially novel mechanism of tricyclic antidepressants is to increase the expression and functioning of gap junctions in astrocytes. EXPERIMENTAL APPROACH The effect of amitriptyline on the expression of Cx43 and gap junction intercellular communication (GJIC) in rat primary cultured cortical astrocytes was investigated. We also investigated the role of p38 MAPK intracellular signalling pathway in the amitriptyline-induced expression of Cx43 and GJIC. KEY RESULTS Treatment with amitriptyline for 48 h significantly up-regulated Cx43 mRNA, protein and GJIC. The up-regulation of Cx43 was not monoamine-related since noradrenaline, 5-HT and dopamine did not induce Cx43 expression and pretreatment with α- and β-adrenoceptor antagonists had no effect. Intracellular signalling involved p38 MAPK, as amitriptyline significantly increased p38 MAPK phosphorylation and Cx43 expression and GJIC were significantly blocked by the p38 inhibitor SB 202190. Furthermore, amitriptyline-induced Cx43 expression and GJIC were markedly reduced by transcription factor AP-1 inhibitors (curcumin and tanshinone IIA). The translocation of c-Fos from the cytosol and the nucleus of cortical astrocytes was increased by amitriptyline, and this response was dependent on p38 activity. CONCLUSION AND IMPLICATION These findings indicate a novel mechanism of action of amitriptyline through cortical astrocytes, and further suggest that targeting this mechanism could lead to the development of a new class of antidepressants.
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Affiliation(s)
- N Morioka
- Department of Pharmacology, Hiroshima University Graduate School of Biomedical & Health Sciences, Minami-ku, Hiroshima, Japan
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Bosson A, Boisseau S, Buisson A, Savasta M, Albrieux M. Disruption of dopaminergic transmission remodels tripartite synapse morphology and astrocytic calcium activity within substantia nigra pars reticulata. Glia 2014; 63:673-83. [PMID: 25511180 DOI: 10.1002/glia.22777] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 12/01/2014] [Indexed: 11/09/2022]
Abstract
The substantia nigra pars reticulata (SNr) is a major output nucleus of the basal ganglia circuitry particularly sensitive to pathological dopamine depletion. Indeed, hyperactivity of SNr neurons is known to be responsible for some motor disorders characteristic of Parkinson's disease. The neuronal processing of basal ganglia dysfunction is well understood but, paradoxically, the role of astrocytes in the regulation of SNr activity has rarely been considered. We thus investigated the influence of the disruption of dopaminergic transmission on plastic changes at tripartite glutamatergic synapses in the rat SNr and on astrocyte calcium activity. In 6-hydroxydopamine-lesioned rats, we observed structural plastic changes of tripartite glutamatergic synapses and perisynaptic astrocytic processes. These findings suggest that subthalamonigral synapses undergo morphological changes that accompany the pathophysiological processes of Parkinson's disease. The pharmacological blockade of dopaminergic transmission (with sulpiride and SCH-23390) increased astrocyte calcium excitability, synchrony and gap junction coupling within the SNr, suggesting a functional adaptation of astrocytes to dopamine transmission disruption in this output nucleus. This hyperactivity is partly reversed by subthalamic nucleus high-frequency stimulation which has emerged as an efficient symptomatic treatment for Parkinson's disease. Therefore, our results demonstrate structural and functional reshaping of neuronal and glial elements highlighting a functional plasticity of neuroglial interactions when dopamine transmission is disrupted.
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Affiliation(s)
- Anthony Bosson
- Inserm, U836, 38000, Grenoble, France; Univ. Grenoble Alpes, Grenoble Institut des Neurosciences, 38000, Grenoble, France
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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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Inhibition of neuroinflammation and mitochondrial dysfunctions by carbenoxolone in the rotenone model of Parkinson's disease. Mol Neurobiol 2014; 51:209-19. [PMID: 24946750 DOI: 10.1007/s12035-014-8769-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 06/01/2014] [Indexed: 12/21/2022]
Abstract
α-Synuclein aggregation contributes to the Parkinson's disease (PD) pathology in multiple ways-the two most important being the activation of neuroinflammation and mitochondrial dysfunction. Our recent studies have shown the beneficial effects of a heat shock protein (HSP) inducer, carbenoxolone (Cbx), in reducing the aggregation of α-synuclein in a rotenone-based rat model of PD. The present study was designed to explore its ability to attenuate the α-synuclein-mediated alterations in neuroinflammation and mitochondrial functions. The PD model was generated by the rotenone administration (2 mg/kg b.wt.) to the male SD rats for a period of 5 weeks. Cbx (20 mg/kg b.wt.) co-administration was seen to reduce the activation of astrocytes incited by rotenone. Subsequently, the release of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β was inhibited. Further, the expression level of various inflammatory mediators such as COX-2, iNOS, and NF-κB was also reduced following Cbx co-treatment. Cbx was also shown to reduce the rotenone-induced decline in activity of mitochondrial complexes-I, -II, and -IV. Protection of mitochondrial functions and reduction in neuroinflammation lead to the lesser production of ROS and subsequently reduced oxidative stress. This was reflected by the increase in both the cytosolic and mitochondrial GSH levels as well as SOD activity during Cbx co-treatment. Thus, Cbx reduces the inflammatory response and improves the mitochondrial dysfunctions by reducing α-synuclein aggregation. In addition, it also reduces the associated oxidative stress. Due to its ability to target the multiple pathways implicated in the PD, Cbx can serve as a highly beneficial prophylactic agent.
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Affiliation(s)
- Hideyuki Takeuchi
- Department of Neuroimmunology; Research Institute of Environmental Medicine; Nagoya University; Nagoya Japan
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Gao L, Gao H, Zhou H, Xu Y. Gene expression profiling analysis of the putamen for the investigation of compensatory mechanisms in Parkinson's disease. BMC Neurol 2013; 13:181. [PMID: 24256571 PMCID: PMC4225573 DOI: 10.1186/1471-2377-13-181] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/28/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Parkinson's disease (PD) is affecting 5 million people worldwide, but the response mechanisms of the striatum are still unclear. Therefore, identification of gene expression alterations in the striatum will greatly assist the development of novel therapy strategies. METHODS We performed a comprehensive gene expression analysis in 15 PD patients and 15 normal controls to identify differentially expressed genes (DEGs) using the expression profile GSE20291 from Gene Expression Omnibus (GEO). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment analysis were used to define functions and pathways altered in PD. Protein-protein interaction network was constructed to find out the modules with close interactions. RESULTS Total715 DEGs including 268 up-regulated and 447 down-regulated genes were obtained. GO functional enrichment analysis indicated that the genes related with neurons function and cell morphogenesis might be changed upon PD. KEGG pathway enrichment analysis showed that most of the genes were enriched in the nodes of Gap junction, calcium signaling pathway, phosphatidylinositol signaling system, long-term potentiation, Alzheimer's disease and GnRH signaling pathway. Protein-protein interaction network and module analysis suggested that some apoptosis related genes, such as PRKCA, CDC42 and BCL2 may play critical roles in striatal neurons growth. CONCLUSION Intrinsic striatal tyrosine hydroxylase interneurons growth may be promoted by changes in several genes expression and thus reduce the functional excitatory synapses.
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Affiliation(s)
- Lianbo Gao
- Department of Neurology, the Fourth Affiliated Hospital of China Medical University, NO,4 chongshan Road, huanggu Area, Shenyang 110032, Liaoning, China.
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Wang Y, Wu Z, Liu X, Fu Q. Gastrodin ameliorates Parkinson's disease by downregulating connexin 43. Mol Med Rep 2013; 8:585-90. [PMID: 23783886 DOI: 10.3892/mmr.2013.1535] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 06/13/2013] [Indexed: 11/06/2022] Open
Abstract
Gastrodin, the predominant constituent of a Chinese herbal medicine, has been utilized in the prevention of Parkinson's disease (PD); however, its mechanism of action remains unknown. Astrocytes are involved in PD and are proposed to be coupled with gap junction connexin 43 (Cx43). To evaluate the effects of gastrodin on PD, the effect of gastrodin on Cx43 in astrocytes and in a PD model were observed. Different doses of gastrodin were added to the astrocyte culture medium or injected into the rotenone model of PD. The relative expression of Cx43 was determined by qPCR and western blot analysis, while gap junctional intercellular communication (GJIC) was quantified using fluorescence recovery after photobleaching (FRAP). The phosphorylated Cx43 was significantly inhibited by gastrodin and the quantity of GJIC was significantly downregulated compared with that of the control cells (P<0.05). In addition, in the rat model of PD induced by rotenone, phosphorylated Cx43 was selectively enhanced in the striatal and hippocampal regions. The enhanced activity was inhibited significantly by gastrodin treatment (P<0.01). Gastrodin results in the prevention of PD by reducing the expression of Cx43 and inhibiting the phosphorylation of Cx43; therefore, it may offer a potential therapeutic alternative for patients with PD.
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Affiliation(s)
- Yu Wang
- Department of Neurology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
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Zhang FF, Morioka N, Nakashima-Hisaoka K, Nakata Y. Spinal astrocytes stimulated by tumor necrosis factor-α and/or interferon-γ attenuate connexin 43-gap junction via c-jun terminal kinase activity. J Neurosci Res 2013; 91:745-56. [DOI: 10.1002/jnr.23213] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 12/27/2012] [Accepted: 01/13/2013] [Indexed: 12/27/2022]
Affiliation(s)
- Fang Fang Zhang
- Department of Pharmacology; Graduate School of Biomedical and Health Sciences; Hiroshima University; Hiroshima; Japan
| | - Norimitsu Morioka
- Department of Pharmacology; Graduate School of Biomedical and Health Sciences; Hiroshima University; Hiroshima; Japan
| | - Kazue Nakashima-Hisaoka
- Department of Pharmacology; Graduate School of Biomedical and Health Sciences; Hiroshima University; Hiroshima; Japan
| | - Yoshihiro Nakata
- Department of Pharmacology; Graduate School of Biomedical and Health Sciences; Hiroshima University; Hiroshima; Japan
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Eugenin EA, Basilio D, Sáez JC, Orellana JA, Raine CS, Bukauskas F, Bennett MVL, Berman JW. The role of gap junction channels during physiologic and pathologic conditions of the human central nervous system. J Neuroimmune Pharmacol 2012; 7:499-518. [PMID: 22438035 PMCID: PMC3638201 DOI: 10.1007/s11481-012-9352-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 02/28/2012] [Indexed: 12/15/2022]
Abstract
Gap junctions (GJs) are expressed in most cell types of the nervous system, including neuronal stem cells, neurons, astrocytes, oligodendrocytes, cells of the blood brain barrier (endothelial cells and astrocytes) and under inflammatory conditions in microglia/macrophages. GJs connect cells by the docking of two hemichannels, one from each cell with each hemichannel being formed by 6 proteins named connexins (Cx). Unapposed hemichannels (uHC) also can be open on the surface of the cells allowing the release of different intracellular factors to the extracellular space. GJs provide a mechanism of cell-to-cell communication between adjacent cells that enables the direct exchange of intracellular messengers, such as calcium, nucleotides, IP(3), and diverse metabolites, as well as electrical signals that ultimately coordinate tissue homeostasis, proliferation, differentiation, metabolism, cell survival and death. Despite their essential functions in physiological conditions, relatively little is known about the role of GJs and uHC in human diseases, especially within the nervous system. The focus of this review is to summarize recent findings related to the role of GJs and uHC in physiologic and pathologic conditions of the central nervous system.
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Affiliation(s)
- Eliseo A Eugenin
- Department of Pathology, F727, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA.
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Cabezas R, El-Bachá RS, González J, Barreto GE. Mitochondrial functions in astrocytes: neuroprotective implications from oxidative damage by rotenone. Neurosci Res 2012; 74:80-90. [PMID: 22902554 DOI: 10.1016/j.neures.2012.07.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 07/25/2012] [Accepted: 07/26/2012] [Indexed: 12/21/2022]
Abstract
Mitochondria are critical for cell survival and normal development, as they provide energy to the cell, buffer intracellular calcium, and regulate apoptosis. They are also major targets of oxidative stress, which causes bioenergetics failure in astrocytes through the activation of different mechanisms and production of oxidative molecules. This review provides an insightful overview of the recent discoveries and strategies for mitochondrial protection in astrocytes. We also discuss the importance of rotenone as an experimental approach for assessing oxidative stress in the brain and delineate some molecular strategies that enhance mitochondrial function in astrocytes as a promising strategy against brain damage.
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Affiliation(s)
- Ricardo Cabezas
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, DC, Colombia
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Glial connexin expression and function in the context of Alzheimer's disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:2048-57. [PMID: 22008509 DOI: 10.1016/j.bbamem.2011.10.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 09/20/2011] [Accepted: 10/03/2011] [Indexed: 01/26/2023]
Abstract
A hallmark of neurodegenerative diseases is the reactive gliosis characterized by a phenotypic change in astrocytes and microglia. This glial response is associated with modifications in the expression and function of connexins (Cxs), the proteins forming gap junction channels and hemichannels. Increased Cx expression is detected in most reactive astrocytes located at amyloid plaques, the histopathological lesions typically present in the brain of Alzheimer's patients and animal models of the disease. The activity of Cx channels analyzed in vivo as well as in vitro after treatment with the amyloid β peptide is also modified and, in particular, hemichannel activation may contribute to neuronal damage. In this review, we summarize and discuss recent data that suggest glial Cx channels participate in the neurodegenerative process of Alzheimer's disease. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Zhang S, Liang R, Zhou F, Huang X, Ding JH, Hu G. Reversal of rotenone-induced dysfunction of astrocytic connexin43 by opening mitochondrial ATP-sensitive potassium channels. Cell Mol Neurobiol 2010; 31:111-7. [PMID: 20824494 DOI: 10.1007/s10571-010-9560-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 08/25/2010] [Indexed: 12/21/2022]
Abstract
Growing evidence suggests that the astrocytic gap junctions (GJs), mainly formed by connexin 43 (Cx43), play an important role in physiological maintenance and various central nervous system (CNS) pathological conditions. However, little is known about the role of Cx43 in Parkinson's disease (PD). In this article, we report that rotenone, a classic neurotoxin for PD, could inhibit expression of astrocytic Cx43 and gap junction permeability. ATP-sensitive potassium (K(ATP)) channel openers, iptakalim (IPT) and diazoxide (DZ), exerted protective effect on rotenone-induced dysfunction of Cx43 and astrocyte apoptosis, which was reversed by selective mitochondrial K(ATP) (mitoK(ATP)) channel blocker 5-hydroxydecanoate (5-HD). Taken together, our findings reveal that rotenone-induced dysfunction of astrocytic Cx43 may be involved in the pathology of PD. Moreover, opening mitoK(ATP) channels in astrocytes can reverse rotenone-induced dysfunction of astrocytic Cx43 and therefore protect against toxicity of rotenone on astrocytes.
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Affiliation(s)
- Shu Zhang
- Department of Pharmacology, Nanjing Medical University, Jiangsu, People's Republic of China
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Li DQ. Wuling Capsule promotes hippocampal neurogenesis by improving expression of connexin 43 in rats exposed to chronic unpredictable mild stress. ACTA ACUST UNITED AC 2010; 8:662-9. [DOI: 10.3736/jcim20100710] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Majoul IV, Onichtchouk D, Butkevich E, Wenzel D, Chailakhyan LM, Duden R. Limiting transport steps and novel interactions of Connexin-43 along the secretory pathway. Histochem Cell Biol 2009; 132:263-80. [PMID: 19626334 PMCID: PMC2756399 DOI: 10.1007/s00418-009-0617-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2009] [Indexed: 12/25/2022]
Abstract
Connexins are four-transmembrane-domain proteins expressed in all vertebrates which form permeable gap junction channels that connect cells. Here, we analysed Connexin-43 (Cx43) transport to the plasma membrane and studied the effects of small GTPases acting along the secretory pathway. We show that both GTP- and GDP-restricted Sar1 prevents exit of Cx43 from the endoplasmic reticulum (ER), but only GTP-restricted Sar1 arrests Cx43 in COP II-coated ER exit sites and accumulates 14-3-3 proteins in the ER fraction. FRET-FLIM data confirm that already in ER exit sites Cx43 exists in oligomeric form, suggesting an in vivo role for 14-3-3 in Cx43 oligomerization. Exit of Cx43 from the ER can be blocked by other factors—such as expression of the β subunit of the COP I coat or p50/dynamitin that acts on the microtubule-based dynein motor complex. GTP-restricted Arf1 blocks Cx43 in the Golgi. Lastly, we show that GTP-restricted Arf6 removes Cx43 gap junction plaques from the cell–cell interface and targets them to degradation. These data provide a molecular explanation of how small GTPases act to regulate Cx43 transport through the secretory pathway, facilitating or abolishing cell–cell communication through gap junctions.
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Affiliation(s)
- Irina V. Majoul
- Institute of Biology, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Daria Onichtchouk
- Developmental Biology Unit, Department of Biology I, University of Freiburg, Freiburg, Germany
| | - Eugenia Butkevich
- Department of Neurophysiology, University of Göttingen, Göttingen, Germany
| | - Dirk Wenzel
- Department of Neurobiology, Max-Planck-Institute of Biophysical Chemistry, Göttingen, Germany
| | - Levon M. Chailakhyan
- Department of Cellular Biophysics and Intercellular Communications, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290 Moscow, Russia
| | - Rainer Duden
- Institute of Biology, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
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