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Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
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Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
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Yu Y, Liang Q, Du L, Jiang H, Gu J, Hu H, Tu Z. Synthesis and Characterization of a Specific Iodine-125-Labeled TRPC5 Radioligand. ChemMedChem 2020; 15:1854-1860. [PMID: 32717096 PMCID: PMC8544919 DOI: 10.1002/cmdc.202000339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Indexed: 11/11/2022]
Abstract
The nonselective Ca2+ -permeable transient receptor potential channel subfamily member 5 (TRPC5) belongs to the transient receptor potential canonical (TRPC) superfamily and is widely expressed in the brain. Compelling evidence reveals that TRPC5 plays crucial roles in depression and other psychiatric disorders. To develop a TRPC5 radioligand, following up on our previous effort, we synthesized the iodine compound TZ66127 and its iodine-125-labeled counterpart [125 I]TZ66127. The synthesis of TZ66127 was achieved by replacing chloride with iodide in the structure of HC608, and the [125 I]TZ66127 was radiosynthesized using its corresponding tributylstannylated precursor. We established a stable human TRPC5-overexpressed HEK293-hTRPC5 cell line and performed Ca2+ imaging and a cell-binding assay study of TZ66127; these indicated that TZ66127 had good inhibition activity for TRPC5, and the inhibitory efficiency of TZ66127 toward TRPC5 presented in a dose-dependent manner. An in vitro autoradiography and immunohistochemistry study of rat brain sections suggested that [125 I]TZ66127 had binding specificity toward TRPC5. Altogether, [125 I]TZ66127 has high potential to serve as a radioligand for screening the binding activity of other new compounds toward TRPC5. The availability of [125 I]TZ66127 might facilitate the development of therapeutic drugs and PET imaging agents that target TRPC5.
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Affiliation(s)
- Yanbo Yu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Qianwa Liang
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Lixia Du
- Department of Anesthesiology, Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hao Jiang
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jiwei Gu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hongzhen Hu
- Department of Anesthesiology, Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Maria-Ferreira D, de Oliveira NMT, da Silva LCM, Fernandes ES. Evidence of a Role for the TRPC Subfamily in Mediating Oxidative Stress in Parkinson's Disease. Front Physiol 2020; 11:332. [PMID: 32457638 PMCID: PMC7225354 DOI: 10.3389/fphys.2020.00332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/23/2020] [Indexed: 12/20/2022] Open
Abstract
Parkinson's disease (PD) represents one of the most common multifactorial neurodegenerative disorders affecting the elderly population. It is associated with the aggregation of α-synuclein protein and the loss of dopaminergic neurons in the substantia nigra pars compacta of the brain. The disease is mainly represented by motor symptoms, such as resting tremors, postural instability, rigidity, and bradykinesia, that develop slowly over time. Parkinson's disease can also manifest as disturbances in non-motor functions. Although the pathology of PD has not yet been fully understood, it has been suggested that the disruption of the cellular redox status may contribute to cellular oxidative stress and, thus, to cell death. The generation of reactive oxygen species and reactive nitrogen intermediates, as well as the dysfunction of dopamine metabolism, play important roles in the degeneration of dopaminergic neurons. In this context, the transient receptor potential channel canonical (TRPC) sub-family plays an important role in neuronal degeneration. Additionally, PD gene products, including DJ-1, SNCA, UCH-L1, PINK-1, and Parkin, also interfere with mitochondrial function leading to reactive oxygen species production and dopaminergic neuronal vulnerability to oxidative stress. Herein, we discuss the interplay between these various biochemical and molecular events that ultimately lead to dopaminergic signaling disruption, highlighting the recently identified roles of TRPC in PD.
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Affiliation(s)
- Daniele Maria-Ferreira
- Faculdades Pequeno Príncipe, Programa de Pós-graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente, Curitiba, Brazil
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil
| | - Natalia Mulinari Turin de Oliveira
- Faculdades Pequeno Príncipe, Programa de Pós-graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente, Curitiba, Brazil
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil
| | - Liziane Cristine Malaquias da Silva
- Faculdades Pequeno Príncipe, Programa de Pós-graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente, Curitiba, Brazil
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil
| | - Elizabeth Soares Fernandes
- Faculdades Pequeno Príncipe, Programa de Pós-graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente, Curitiba, Brazil
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil
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Park SE, Song JH, Hong C, Kim DE, Sul JW, Kim TY, Seo BR, So I, Kim SY, Bae DJ, Park MH, Lim HM, Baek IJ, Riccio A, Lee JY, Shim WH, Park B, Koh JY, Hwang JJ. Contribution of Zinc-Dependent Delayed Calcium Influx via TRPC5 in Oxidative Neuronal Death and its Prevention by Novel TRPC Antagonist. Mol Neurobiol 2018; 56:2822-2835. [PMID: 30062674 PMCID: PMC6459797 DOI: 10.1007/s12035-018-1258-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/17/2018] [Indexed: 11/29/2022]
Abstract
Oxidative stress is a key mediator of neuronal death in acute brain injuries, such as epilepsy, trauma, and stroke. Although it is accompanied by diverse cellular changes, increases in levels of intracellular zinc ion (Zn2+) and calcium ion (Ca2+) may play a critical causative role in oxidative neuronal death. However, the mechanistic link between Zn2+ and Ca2+ dyshomeostasis in neurons during oxidative stress is not well-understood. Here, we show that the exposure of cortical neurons to H2O2 led to a zinc-triggered calcium influx, which resulted in neuronal death. The cyclin-dependent kinase inhibitor, NU6027, inhibited H2O2-induced Ca2+ increases and subsequent cell death in cortical neurons, without affecting the early increase in Zn2+. Therefore, we attempted to identify the zinc-regulated Ca2+ pathway that was inhibited by NU6027. The expression profile in cortical neurons identified transient receptor potential cation channel 5 (TRPC5) as a candidate that is known to involve in the generation of epileptiform burst firing and epileptic neuronal death (Phelan KD et al. 2012a; Phelan KD et al. 2013b). NU6027 inhibited basal and zinc-augmented TRPC5 currents in TRPC5-overexpressing HEK293 cells. Consistently, cortical neurons from TRPC5 knockout mice were highly resistant to H2O2-induced death. Moreover, NU6027 is neuroprotective in kainate-treated epileptic rats. Our results demonstrate that TRPC5 is a novel therapeutic target against oxidative neuronal injury in prolonged seizures and that NU6027 is a potent inhibitor of TRPC5.
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Affiliation(s)
- Sang Eun Park
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - Ji Hoon Song
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - Chansik Hong
- Department of Physiology, Chosun University School of Medicine, Kwangju, 61452, South Korea
| | - Dong Eun Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - Jee-Won Sul
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - Tae-Youn Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea.,Neural Injury Research Lab, University of Ulsan College of Medicine, Seoul, 05505, South Korea
| | - Bo-Ra Seo
- Neural Injury Research Lab, University of Ulsan College of Medicine, Seoul, 05505, South Korea
| | - Insuk So
- Department of Physiology and Institute of Dermatological Science, Seoul National University College of Medicine, Seoul, 110-799, South Korea
| | - Sang-Yeob Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-Gu, Seoul, 05505, South Korea
| | - Dong-Jun Bae
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - Mi-Ha Park
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - Hye Min Lim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - In-Jeoung Baek
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-Gu, Seoul, 05505, South Korea
| | - Antonio Riccio
- Department of Cardiology, Boston Children's Hospital, Boston, MA, USA.,Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Joo-Yong Lee
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-Gu, Seoul, 05505, South Korea
| | - Woo Hyun Shim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-Gu, Seoul, 05505, South Korea
| | - Bumwoo Park
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea.,Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea
| | - Jae-Young Koh
- Neural Injury Research Lab, University of Ulsan College of Medicine, Seoul, 05505, South Korea. .,Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-Gu, Seoul, 05505, South Korea.
| | - Jung Jin Hwang
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea. .,Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-Gu, Seoul, 05505, South Korea.
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Iffland PH, Crino PB. Focal Cortical Dysplasia: Gene Mutations, Cell Signaling, and Therapeutic Implications. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2017; 12:547-571. [PMID: 28135561 DOI: 10.1146/annurev-pathol-052016-100138] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Focal cortical dysplasias (FCDs) are malformations of cortical development (MCDs) that are highly associated with medication-resistant epilepsy and are the most common cause of neocortical epilepsy in children. FCDs are a heterogeneous group of developmental disorders caused by germline or somatic mutations that occur in genes regulating the PI3K/Akt/mTOR pathway-a key pathway in neuronal growth and migration. Accordingly, FCDs are characterized by abnormal cortical lamination, cell morphology (e.g., cytomegaly), and cellular polarity. In some FCD subtypes, balloon cells express proteins typically seen in neuroglial progenitor cells. Because recurrent intractable seizures are a common feature of FCDs, epileptogenic electrophysiological properties are also observed in addition to local inflammation. Here, we will summarize the current literature regarding FCDs, addressing the current classification system, histopathology, molecular genetics, electrophysiology, and transcriptome and cell signaling changes.
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Affiliation(s)
- Philip H Iffland
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania 19140;
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland 21201;
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