101
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Kumar H, Lim CS, Choi H, Joshi HP, Kim KT, Kim YH, Park CK, Kim HM, Han IB. Elevated TRPV4 Levels Contribute to Endothelial Damage and Scarring in Experimental Spinal Cord Injury. J Neurosci 2020; 40:1943-1955. [PMID: 31974206 PMCID: PMC7046444 DOI: 10.1523/jneurosci.2035-19.2020] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 12/10/2019] [Accepted: 01/04/2020] [Indexed: 11/21/2022] Open
Abstract
Currently, the role of transient receptor potential vanilloid type 4 (TRPV4), a nonselective cation channel in the pathology of spinal cord injury (SCI), is not recognized. Herein, we report the expression and contribution of TRPV4 in the pathology of scarring and endothelial and secondary damage after SCI. TRPV4 expression increased during the inflammatory phase in female rats after SCI and was expressed primarily by cells at endothelial-microglial junctions. Two-photon microscopy of intracellular-free Ca2+ levels revealed a biphasic increase at similar time points after SCI. Expression of TRPV4 at the injury epicenter, but not intracellular-free Ca2+, progressively increases with the severity of the injury. Activation of TRPV4 with specific agonist altered the organization of endothelial cells, affected tight junctions in the hCMEC/D3 BBB cell line in vitro, and increases the scarring in rat spinal cord as well as induced endothelial damage. By contrast, suppression of TRPV4 with a specific antagonist or in female Trpv4 KO mouse attenuated inflammatory cytokines and chemokines, prevented the degradation of tight junction proteins, and preserve blood-spinal cord barrier integrity, thereby attenuate the scarring after SCI. Likewise, secondary damage was reduced, and behavioral outcomes were improved in Trpv4 KO mice after SCI. These results suggest that increased TRPV4 expression disrupts endothelial cell organization during the early inflammatory phase of SCI, resulting in tissue damage, vascular destabilization, blood-spinal cord barrier breakdown, and scarring. Thus, TRPV4 inhibition/knockdown represents a promising therapeutic strategy to stabilize/protect endothelial cells, attenuate nociception and secondary damage, and reduce scarring after SCI.SIGNIFICANCE STATEMENT TRPV4, a calcium-permeable nonselective cation channel, is widely expressed in both excitable and nonexcitable cells. Spinal cord injury (SCI) majorly caused by trauma/accidents is associated with changes in osmolarity, mechanical injury, and shear stress. After SCI, TRPV4 was increased and were found to be linked with the severity of injury at the epicenter at the time points that were reported to be critical for repair/treatment. Activation of TRPV4 was damaging to endothelial cells that form the blood-spinal cord barrier and thus contributes to scarring (glial and fibrotic). Importantly, inhibition/knockdown of TRPV4 prevented these effects. Thus, the manipulation of TRPV4 signaling might lead to new therapeutic strategies or combinatorial therapies to protect endothelial cells and enhance repair after SCI.
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Affiliation(s)
- Hemant Kumar
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488
| | - Chang Su Lim
- Department of Energy System Research and Department of Chemistry, Ajou University, Suwon, Gyeonggi-do, Republic of Korea, 16499
| | - Hyemin Choi
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488
| | - Hari Prasad Joshi
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488
| | - Kyoung-Tae Kim
- Department of Neurosurgery, School of Medicine, Kyungpook National University, Daegu, Republic of Korea, 41944
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Republic of Korea, 41944, and
| | - Yong Ho Kim
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon, Republic of Korea, 13120
| | - Chul-Kyu Park
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon, Republic of Korea, 13120
| | - Hwan Myung Kim
- Department of Energy System Research and Department of Chemistry, Ajou University, Suwon, Gyeonggi-do, Republic of Korea, 16499
| | - In-Bo Han
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488,
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102
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Wypych D, Pomorski P. Calcium Signaling in Glioma Cells: The Role of Nucleotide Receptors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1202:67-86. [PMID: 32034709 DOI: 10.1007/978-3-030-30651-9_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Calcium signaling is probably one of the evolutionary oldest and the most common way by which the signal can be transmitted from the cell environment to the cytoplasmic calcium binding effectors. Calcium signal is fast and due to diversity of calcium binding proteins it may have a very broad effect on cell behavior. Being a crucial player in neuronal transmission it is also very important for glia physiology. It is responsible for the cross-talk between neurons and astrocytes, for microglia activation and motility. Changes in calcium signaling are also crucial for the behavior of transformed glioma cells. The present chapter summarizes molecular mechanisms of calcium signal formation present in glial cells with a strong emphasis on extracellular nucleotide-evoked signaling pathways. Some aspects of glioma C6 signaling such as the cross-talk between P2Y1 and P2Y12 nucleotide receptors in calcium signal generation will be discussed in-depth, to show complexity of machinery engaged in formation of this signal. Moreover, possible mechanisms of modulation of the calcium signal in diverse environments there will be presented herein. Finally, the possible role of calcium signal in glioma motility is also discussed. This is a very important issue, since glioma cells, contrary to the vast majority of neoplastic cells, cannot spread in the body with the bloodstream and, at least in early stages of tumor development, may expand only by means of sheer motility.
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Affiliation(s)
- Dorota Wypych
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Paweł Pomorski
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
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103
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Lee SY, Lee HJ, Kim YK. Comparative transcriptome profiling of selected osmotic regulatory proteins in the gill during seawater acclimation of chum salmon (Oncorhynchus keta) fry. Sci Rep 2020; 10:1987. [PMID: 32029805 PMCID: PMC7005315 DOI: 10.1038/s41598-020-58915-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 01/22/2020] [Indexed: 02/06/2023] Open
Abstract
Salmonid fishes, chum salmon (Oncorhynchus keta) have the developed adaptive strategy to withstand wide salinity changes from the early life stage. This study investigated gene expression patterns of cell membrane proteins in the gill of chum salmon fry on the transcriptome level by tracking the salinity acclimation of the fish in changing environments ranging from freshwater (0 ppt) to brackish water (17.5 ppt) to seawater (35 ppt). Using GO analysis of DEGs, the known osmoregulatory genes and their functional groups such as ion transport, transmembrane transporter activity and metal ion binding were identified. The expression patterns of membrane protein genes, including pump-mediated protein (NKA, CFTR), carrier-mediated protein (NKCC, NHE3) and channel-mediated protein (AQP) were similar to those of other salmonid fishes in the smolt or adult stages. Based on the protein-protein interaction analysis between transmembrane proteins and other related genes, we identified osmotic-related genes expressed with salinity changes and analyzed their expression patterns. The findings of this study may facilitate the disentangling of the genetic basis of chum salmon and better able an understanding of the osmophysiology of the species.
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Affiliation(s)
- Sang Yoon Lee
- The East Coast Research Institute of Life Science, Gangneung-Wonju National University, Gangneung, 25457, South Korea
| | - Hwa Jin Lee
- Department of Marine Biotechnology, Gangneung-Wonju National University, Gangneung, 25457, South Korea
| | - Yi Kyung Kim
- The East Coast Research Institute of Life Science, Gangneung-Wonju National University, Gangneung, 25457, South Korea.
- Department of Marine Biotechnology, Gangneung-Wonju National University, Gangneung, 25457, South Korea.
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104
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The Regulation of Uterine Function During Parturition: an Update and Recent Advances. Reprod Sci 2020; 27:3-28. [DOI: 10.1007/s43032-019-00001-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/19/2019] [Indexed: 12/13/2022]
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105
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Ciura S, Prager-Khoutorsky M, Thirouin ZS, Wyrosdic JC, Olson JE, Liedtke W, Bourque CW. Trpv4 Mediates Hypotonic Inhibition of Central Osmosensory Neurons via Taurine Gliotransmission. Cell Rep 2019; 23:2245-2253. [PMID: 29791836 DOI: 10.1016/j.celrep.2018.04.090] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 01/15/2018] [Accepted: 04/19/2018] [Indexed: 12/21/2022] Open
Abstract
The maintenance of hydromineral homeostasis requires bidirectional detection of changes in extracellular fluid osmolality by primary osmosensory neurons (ONs) in the organum vasculosum laminae terminalis (OVLT). Hypertonicity excites ONs in part through the mechanical activation of a variant transient receptor potential vanilloid-1 channel (dn-Trpv1). However, the mechanism by which local hypotonicity inhibits ONs in the OVLT remains unknown. Here, we show that hypotonicity can reduce the basal activity of dn-Trpv1 channels and hyperpolarize acutely isolated ONs. Surprisingly, we found that mice lacking dn-Trpv1 maintain normal inhibitory responses to hypotonicity when tested in situ. In the intact setting, hypotonicity inhibits ONs through a non-cell-autonomous mechanism that involves glial release of the glycine receptor agonist taurine through hypotonicity activated anion channels (HAAC) that are activated subsequent to Ca2+ influx through Trpv4 channels. Our study clarifies how Trpv4 channels contribute to the inhibition of OVLT ONs during hypotonicity in situ.
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Affiliation(s)
- Sorana Ciura
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC H3G1A4, Canada.
| | - Masha Prager-Khoutorsky
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC H3G1A4, Canada
| | - Zahra S Thirouin
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC H3G1A4, Canada
| | - Joshua C Wyrosdic
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC H3G1A4, Canada
| | - James E Olson
- Department of Emergency Medicine/Department of Neuroscience, Cell Biology and Physiology, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA
| | - Wolfgang Liedtke
- Centre for Translational Neuroscience, 201G Bryan Research Bldg. Box 2900, Duke University Medical Centre, Durham, NC 27710, USA
| | - Charles W Bourque
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC H3G1A4, Canada.
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106
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Tsushima H, Mori-Kawabe M. Central Transient Receptor Potential Vanilloid 4 Contributes to Systemic Water Homeostasis through Urinary Excretion. Biol Pharm Bull 2019; 42:1877-1882. [DOI: 10.1248/bpb.b19-00409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hiromi Tsushima
- Laboratory of Pharmacology, College of Pharmacy, Kinjo Gakuin University
| | - Mayumi Mori-Kawabe
- Department of Cellular and Molecular Pharmacology, Nagoya City University Graduate School of Medical Sciences
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107
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Pairet N, Mang S, Kiechle T, Laufhäger N, Dietl P, Lamb DJ. Differential modulation of transendothelial electrical resistance by TRPV4 agonists is mediated by apoptosis and/or necrosis. Biochem Biophys Rep 2019; 20:100672. [PMID: 31650038 PMCID: PMC6804647 DOI: 10.1016/j.bbrep.2019.100672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 02/15/2019] [Accepted: 07/30/2019] [Indexed: 12/12/2022] Open
Abstract
Transient receptor potential vanilloid 4 (TRPV4) has been implicated in many disease conditions also in the lung. Its activation leads to an increase endothelial permeability in an intracellular calcium-influx dependent manner. We investigated its function in vitro on primary human endothelial cells using two TRPV4 agonists, GSK1016790A and 4α-Phorbol 12,13-didecanoate (4α-PDD) and a selective TRPV4 blocker GSK2193874. Both TRPV4 agonists leaded to a reduction in transendothelial electrical resistance (TER) which was mediated however by differential cytotoxic effects. 4α-PDD induced apoptosis that could not be blocked by TRPV4 inhibition in HUVECs, whereas GSK1016790A selectively activated TRPV4 and reduced TER as a consequence of cellular necrosis. TRPV4 mediated cytotoxicity is poorly described and may provide significant context to the role of TRPV4 in barrier-function. TRPV4 agonism is widely associated with barrier-dysfunction. We show TRPV4 mediated increased membrane permeability is caused by cytotoxicity. The TRPV4 agonist GSK1016790A mediates barrier dysfunction via necrosis. The TRPV4 agonist 4α-PDD mediates barrier dysfunction via apoptosis.
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Affiliation(s)
- N Pairet
- Institute of General Physiology, University of Ulm, Ulm, Germany.,Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, D-88397, Biberach an der Riß, Germany
| | - S Mang
- Immunology & Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, D-88397, Biberach an der Riß, Germany.,Institute of Immunology, Hannover Medical School, D-30625, Hannover, Germany
| | - T Kiechle
- Immunology & Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, D-88397, Biberach an der Riß, Germany
| | - N Laufhäger
- Immunology & Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, D-88397, Biberach an der Riß, Germany
| | - P Dietl
- Institute of General Physiology, University of Ulm, Ulm, Germany
| | - D J Lamb
- Immunology & Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, D-88397, Biberach an der Riß, Germany
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108
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Ducza E, Csányi A, Szőke É, Pohóczky K, Hajagos-Tóth J, Kothencz A, Tiszai Z, Gáspár R. Significance of transient receptor potential vanilloid 4 and aquaporin 5 co-expression in the rat uterus at term. Heliyon 2019; 5:e02697. [PMID: 31687520 PMCID: PMC6820280 DOI: 10.1016/j.heliyon.2019.e02697] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 09/13/2019] [Accepted: 10/16/2019] [Indexed: 12/15/2022] Open
Abstract
Aims Aquaporins (AQPs) are channel proteins that facilitate the rapid passive movement of water. In our studies it was proved that the decreased AQP5 expression is followed by the increase of uterine contractility. The transient receptor potential vanilloid 4 (TRPV4) is a calcium channel, which is activated in response to osmotic changes. Our aim was to determine the possible role of AQP5 in this osmotic regulation of TRPV4, thus in pregnant uterine contraction. Main methods We used RT-PCR and Western blot techniques for the detection of the TRPV4 expression during pregnancy in rat uterus. The localization of AQP5 and TRPV4 was determined by immunohistochemical studies. The role of TRPV4 in uterus contraction was investigated in an isolated organ bath system. In vitro uterus contractions were stimulated with KCl and its effect was investigated with the selective TRPV4 agonist (RN1747) and antagonist (RN1734). Key findings The TRPV4 expression continuously increased from day 18 to the last day of pregnancy. The co-expression of TRPV4 and AQP5 in the myometrium and endometrium was determined in the late pregnant uterus. The TRPV4 antagonist and agonist significantly decreased and increased uterine contraction, respectively, especially on the last day of pregnancy. Significance We presume the decreased AQP5 expression triggers hypertonic stress, which activates TRPV4 and increases uterus contraction on the day of labor. Based on these findings, we suppose the TRPV4 effect on uterus contraction is AQP5 control, which could be a new target in preterm birth therapy.
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Affiliation(s)
- Eszter Ducza
- Department of Pharmacodynamics and Biopharmacy, University of Szeged, Hungary
- Corresponding author.
| | - Adrienn Csányi
- Department of Pharmacodynamics and Biopharmacy, University of Szeged, Hungary
| | - Éva Szőke
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center & Centre for Neuroscience, University of Pécs, Hungary
| | - Krisztina Pohóczky
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center & Centre for Neuroscience, University of Pécs, Hungary
- Department of Pharmacology, Faculty of Pharmacy, University of Pécs, Pécs, Hungary
| | - Judit Hajagos-Tóth
- Department of Pharmacodynamics and Biopharmacy, University of Szeged, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Hungary
| | - Anna Kothencz
- Department of Pharmacodynamics and Biopharmacy, University of Szeged, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Hungary
| | - Zita Tiszai
- Department of Pharmacodynamics and Biopharmacy, University of Szeged, Hungary
| | - Róbert Gáspár
- Department of Pharmacodynamics and Biopharmacy, University of Szeged, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Hungary
- Corresponding author.
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109
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Toft-Bertelsen TL, Yarishkin O, Redmon S, Phuong TTT, Križaj D, MacAulay N. Volume sensing in the transient receptor potential vanilloid 4 ion channel is cell type-specific and mediated by an N-terminal volume-sensing domain. J Biol Chem 2019; 294:18421-18434. [PMID: 31619514 DOI: 10.1074/jbc.ra119.011187] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/11/2019] [Indexed: 12/29/2022] Open
Abstract
Many retinal diseases are associated with pathological cell swelling, but the underlying etiology remains to be established. A key component of the volume-sensitive machinery, the transient receptor potential vanilloid 4 (TRPV4) ion channel, may represent a sensor and transducer of cell swelling, but the molecular link between the swelling and TRPV4 activation is unresolved. Here, our results from experiments using electrophysiology, cell volumetric measurements, and fluorescence imaging conducted in murine retinal cells and Xenopus oocytes indicated that cell swelling in the physiological range activated TRPV4 in Müller glia and Xenopus oocytes, but required phospholipase A2 (PLA2) activity exclusively in Müller cells. Volume-dependent TRPV4 gating was independent of cytoskeletal rearrangements and phosphorylation. Our findings also revealed that TRPV4-mediated transduction of volume changes is dependent by its N terminus, more specifically by its distal-most part. We conclude that the volume sensitivity and function of TRPV4 in situ depend critically on its functional and cell type-specific interactions.
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Affiliation(s)
- Trine L Toft-Bertelsen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, Bldg. 24.6, 2200 Copenhagen N, Denmark
| | - Oleg Yarishkin
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Sarah Redmon
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Tam T T Phuong
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - David Križaj
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, Utah 84132.
| | - Nanna MacAulay
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, Bldg. 24.6, 2200 Copenhagen N, Denmark.
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110
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Toft-Bertelsen TL, Larsen BR, MacAulay N. Sensing and regulation of cell volume - we know so much and yet understand so little: TRPV4 as a sensor of volume changes but possibly without a volume-regulatory role? Channels (Austin) 2019; 12:100-108. [PMID: 29424275 PMCID: PMC5972811 DOI: 10.1080/19336950.2018.1438009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Cellular volume changes lead to initiation of cell volume regulatory events, the molecular identity of which remains unresolved. We here discuss experimental challenges associated with investigation of volume regulation during application of large, non-physiological osmotic gradients. The TRPV4 ion channel responds to volume increase irrespectively of the molecular mechanism underlying cell swelling, and is thus considered a sensor of volume changes. Evidence pointing towards the involvement of TRPV4 in subsequent volume regulatory mechanisms is intriguing, yet far from conclusive. We here present an experimental setting with astrocytic cell swelling in the absence of externally applied osmotic gradients, and the lack of evidence for involvement of TRPV4 in this regulatory volume response. Our aim with these new data and the preceding discussion is to stimulate further experimental effort in this area of research to clarify the role of TRPV4 and other channels and transporters in regulatory volume responses.
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Affiliation(s)
| | - Brian R Larsen
- a Department of Neuroscience , University of Copenhagen , Copenhagen , Denmark
| | - Nanna MacAulay
- a Department of Neuroscience , University of Copenhagen , Copenhagen , Denmark
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111
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Eilert-Olsen M, Hjukse JB, Thoren AE, Tang W, Enger R, Jensen V, Pettersen KH, Nagelhus EA. Astroglial endfeet exhibit distinct Ca 2+ signals during hypoosmotic conditions. Glia 2019; 67:2399-2409. [PMID: 31350866 DOI: 10.1002/glia.23692] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 11/09/2022]
Abstract
Astrocytic endfeet cover the brain surface and form a sheath around the cerebral vasculature. An emerging concept is that endfeet control blood-brain water transport and drainage of interstitial fluid and waste along paravascular pathways. Little is known about the signaling mechanisms that regulate endfoot volume and hence the width of these drainage pathways. Here, we used the genetically encoded fluorescent Ca2+ indicator GCaMP6f to study Ca2+ signaling within astrocytic somata, processes, and endfeet in response to an osmotic challenge known to induce cell swelling. Acute cortical slices were subjected to artificial cerebrospinal fluid with 20% reduction in osmolarity while GCaMP6f fluorescence was imaged with two-photon microscopy. Ca2+ signals induced by hypoosmotic conditions were observed in all astrocytic compartments except the soma. The Ca2+ response was most prominent in subpial and perivascular endfeet and included spikes with single peaks, plateau-type elevations, and rapid oscillations, the latter restricted to subpial endfeet. Genetic removal of the type 2 inositol 1,4,5-triphosphate receptor (IP3R2) severely suppressed the Ca2+ responses in endfeet but failed to affect brain water accumulation in vivo after water intoxication. Furthermore, the increase in endfoot Ca2+ spike rate during hypoosmotic conditions was attenuated in mutant mice lacking the aquaporin-4 anchoring molecule dystrophin and after blockage of transient receptor potential vanilloid 4 channels. We conclude that the characteristics and underpinning of Ca2+ responses to hypoosmotic stress differ within the astrocytic territory and that IP3R2 is essential for the Ca2+ signals only in subpial and perivascular endfeet.
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Affiliation(s)
- Martine Eilert-Olsen
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Jarand B Hjukse
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Anna E Thoren
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Wannan Tang
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Rune Enger
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Vidar Jensen
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Klas H Pettersen
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Erlend A Nagelhus
- Division of Physiology, Department of Molecular Medicine, GliaLab and Letten Centre, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
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112
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Morishita K, Watanabe K, Ichijo H. Cell volume regulation in cancer cell migration driven by osmotic water flow. Cancer Sci 2019; 110:2337-2347. [PMID: 31120184 PMCID: PMC6676112 DOI: 10.1111/cas.14079] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 12/12/2022] Open
Abstract
Cancer metastasis is the most frequent cause of death for patients with cancer. The main current treatment for cancer metastasis is chemotherapy targeting cancer cells’ ability to proliferate. However, some types of cancer cells show resistance to chemotherapy. Recently, cancer cell migration has become the subject of interest as a novel target of cancer therapy. Cell migration requires many factors, such as the cytoskeleton, cell‐matrix adhesion and cell volume regulation. Here, we focus on cell volume regulation and the role of ion/water transport systems in cell migration. Transport proteins, such as ion channels, ion carriers, and aquaporins, are indispensable for cell volume regulation under steady‐state conditions and during exposure to osmotic stress. Studies from the last ~25 years have revealed that cell volume regulation also plays an important role in the process of cell migration. Water flow in accordance with localized osmotic gradients generated by ion transport contributes to the driving force for cell migration. Moreover, it has been reported that metastatic cancer cells have higher expression of these transport proteins than nonmetastatic cancer cells. Thus, ion/water transport proteins involved in cell volume regulation and cell migration could be novel therapeutic targets for cancer metastasis. In this review, after presenting the importance of ion/water transport systems in cell volume regulation, we discuss the roles of transport proteins in a pathophysiological context, especially in the context of cancer cell migration.
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Affiliation(s)
- Kazuhiro Morishita
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kengo Watanabe
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Hidenori Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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113
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Yu S, Huang S, Ding Y, Wang W, Wang A, Lu Y. Transient receptor potential ion-channel subfamily V member 4: a potential target for cancer treatment. Cell Death Dis 2019; 10:497. [PMID: 31235786 PMCID: PMC6591233 DOI: 10.1038/s41419-019-1708-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 05/13/2019] [Accepted: 05/28/2019] [Indexed: 12/29/2022]
Abstract
The transient receptor potential ion-channel superfamily consists of nonselective cation channels located mostly on the plasma membranes of numerous animal cell types, which are closely related to sensory information transmission (e.g., vision, pain, and temperature perception), as well as regulation of intracellular Ca2+ balance and physiological activities of growth and development. Transient receptor potential ion channel subfamily V (TRPV) is one of the largest and most diverse subfamilies, including TRPV1-TRPV6 involved in the regulation of a variety of cellular functions. TRPV4 can be activated by various physical and chemical stimuli, such as heat, mechanical force, and phorbol ester derivatives participating in the maintenance of normal cellular functions. In recent years, the roles of TRPV4 in cell proliferation, differentiation, apoptosis, and migration have been extensively studied. Its abnormal expression has also been closely related to the onset and progression of multiple tumors, so TRPV4 may be a target for cancer diagnosis and treatment. In this review, we focused on the latest studies concerning the role of TRPV4 in tumorigenesis and the therapeutic potential. As evidenced by the effects on cancerogenesis, TRPV4 is a potential target for anticancer therapy.
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Affiliation(s)
- Suyun Yu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, P. R. China
| | - Shuai Huang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, P. R. China
| | - Yushi Ding
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, P. R. China
| | - Wei Wang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, P. R. China
| | - Aiyun Wang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, P. R. China
- Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine Prevention and Treatment of Tumor, Nanjing University of Chinese Medicine, Nanjing, P. R. China
| | - Yin Lu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, P. R. China.
- Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine Prevention and Treatment of Tumor, Nanjing University of Chinese Medicine, Nanjing, P. R. China.
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114
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Huang Y, Li SN, Zhou XY, Zhang LX, Chen GX, Wang TH, Xia QJ, Liang N, Zhang X. The Dual Role of AQP4 in Cytotoxic and Vasogenic Edema Following Spinal Cord Contusion and Its Possible Association With Energy Metabolism via COX5A. Front Neurosci 2019; 13:584. [PMID: 31258460 PMCID: PMC6587679 DOI: 10.3389/fnins.2019.00584] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 05/23/2019] [Indexed: 02/05/2023] Open
Abstract
Spinal cord edema, mainly including vasogenic and cytotoxic edema, influences neurological outcome after spinal cord contusion (SCC). Aquaporin 4 (AQP4) is the most ubiquitous water channel in the central nervous system (CNS), which is a rate-limiting factor in vasogenic edema expressing in brain injury, and it contributes to the formation of cytotoxic edema locating in astrocytes. However, little is known about the regulatory mechanism of AQP4 within vasogenic and cytotoxic edema in SCC, and whether the regulation mechanism of AQP4 is related to Cytochrome coxidase (COX5A) affecting energy metabolism. Therefore, the SCC model is established by Allen’s method, and the degree of edema and neuronal area is measured. The motor function of rats is evaluated by the Basso, Beattie, and Bresnahan (BBB) scoring system. Meanwhile, AQP4 and COX5A are detected by real-time quantitative PCR (qRT-PCR) and western blot (WB). The localization of targeted protein is exhibited by immunohistochemical staining (IHC) and immunofluorescence (IF). Additionally, the methodology of AQP4 lentivirus-mediated RNA interference (AQP4-RNAi) is used to reveal the effect on edema of SCC and the regulating molecular mechanism. Firstly, we observe that the tissue water content increases after SCC and decreases after the peak value of tissue water content at 3 days (P < 0.05) with abundant expression of AQP4 protein locating around vascular endothelial cells (VECs), which suggests that the increasing AQP4 promotes water reabsorption and improves vasogenic edema in the early stage of SCC. However, the neuronal area is larger than in the sham group in the 7 days (P < 0.05) with the total water content of spinal cord decrease. Meanwhile, AQP4 migrates from VECs to neuronal cytomembrane, which indicates that AQP4 plays a crucial role in aggravating the formation and development of cytotoxic edema in the middle stages of SCC. Secondly, AQP4-RNAi is used to elucidate the mechanism of AQP4 to edema of SCC. The neuronal area shrinks and the area of cytotoxic edema reduces after AQP4 downregulation. The BBB scores are significantly higher than in the vector group after AQP4-RNAi at 5, 7, and 14 (P < 0.05). There is a relationship between AQP4 and COX5A shown by bioinformatics analysis. After AQP4 inhibition, the expression of COX5A is significantly upregulated in the swelling astrocytes. Therefore, the inhibition of AQP4 expression reduces cytotoxic edema in SCC and improves motor function, which may be associated with upregulation of COX5A via affecting energy metabolism. Moreover, it is not clear how the inhibition of AQP4 directly causes the upregulation of COX5A.
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Affiliation(s)
- Yuan Huang
- Clinical Laboratory Medicine, Chengdu Medical College, Chengdu, China
| | - Sheng-Nan Li
- Center for Experimental Technology of Preclinical Medicine, Chengdu Medical College, Chengdu, China
| | - Xiu-Ya Zhou
- Center for Experimental Technology of Preclinical Medicine, Chengdu Medical College, Chengdu, China
| | | | - Gang-Xian Chen
- Center for Experimental Technology of Preclinical Medicine, Chengdu Medical College, Chengdu, China
| | - Ting-Hua Wang
- Institute of Neuroscience, Kunming Medical University, Kunming, China.,Institute of Neurological Diseases, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| | - Qing-Jie Xia
- Institute of Neurological Diseases, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| | - Nan Liang
- Center for Experimental Technology of Preclinical Medicine, Chengdu Medical College, Chengdu, China
| | - Xiao Zhang
- Center for Experimental Technology of Preclinical Medicine, Chengdu Medical College, Chengdu, China
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115
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Rosic B, Dukefoss DB, Åbjørsbråten KS, Tang W, Jensen V, Ottersen OP, Enger R, Nagelhus EA. Aquaporin-4-independent volume dynamics of astroglial endfeet during cortical spreading depression. Glia 2019; 67:1113-1121. [PMID: 30791140 PMCID: PMC6594042 DOI: 10.1002/glia.23604] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 01/02/2019] [Accepted: 02/04/2019] [Indexed: 12/13/2022]
Abstract
Cortical spreading depression (CSD) is a slowly propagating wave of depolarization of gray matter. This phenomenon is believed to underlie the migraine aura and similar waves of depolarization may exacerbate injury in a number of neurological disease states. CSD is characterized by massive ion dyshomeostasis, cell swelling, and multiphasic blood flow changes. Recently, it was shown that CSD is associated with a closure of the paravascular space (PVS), a proposed exit route for brain interstitial fluid and solutes, including excitatory and inflammatory substances that increase in the wake of CSD. The PVS closure was hypothesized to rely on swelling of astrocytic endfeet due to their high expression of aquaporin-4 (AQP4) water channels. We investigated whether CSD is associated with swelling of endfeet around penetrating arterioles in the cortex of living mice. Endfoot cross-sectional area was assessed by two-photon microscopy of mice expressing enhanced green fluorescent protein in astrocytes and related to the degree of arteriolar constriction. In anesthetized mice CSD triggered pronounced endfoot swelling that was short-lasting and coincided with the initial arteriolar constriction. Mice lacking AQP4 displayed volume changes of similar magnitude. CSD-induced endfoot swelling and arteriolar constriction also occurred in awake mice, albeit with faster kinetics than in anesthetized mice. We conclude that swelling of astrocytic endfeet is a robust event in CSD. The early onset and magnitude of the endfoot swelling is such that it may significantly delay perivascular drainage of interstitial solutes in neurological conditions where CSD plays a pathophysiological role.
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Affiliation(s)
- Brana Rosic
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
| | - Didrik B. Dukefoss
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
| | - Knut Sindre Åbjørsbråten
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
| | - Wannan Tang
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
| | - Vidar Jensen
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
| | - Ole Petter Ottersen
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
- Office of the PresidentKarolinska InstitutetStockholmSweden
| | - Rune Enger
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
- Department of NeurologyOslo University HospitalOsloNorway
| | - Erlend A. Nagelhus
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular MedicineInstitute of Basic Medical Sciences, University of OsloOsloNorway
- Department of NeurologyOslo University HospitalOsloNorway
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116
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Tamtaji OR, Behnam M, Pourattar MA, Jafarpour H, Asemi Z. Aquaporin 4: A key player in Parkinson's disease. J Cell Physiol 2019; 234:21471-21478. [PMID: 31127615 DOI: 10.1002/jcp.28871] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 05/09/2019] [Accepted: 05/09/2019] [Indexed: 02/07/2023]
Abstract
Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases which occur in aged people worldwide. Given that a sequence of cellular and molecular mechanisms, including oxidative stresses, apoptosis, inflammatory pathways, microglia, astrocyte activation, and aquaporin 4 (AQP4) are associated with initiation and the progression of PD. AQP4 may affect various pathways (i.e., α-synuclein, inflammatory pathways, and microglia and astrocyte activation). Few reports have evaluated the relationship between AQP4 and PD-related cellular and molecular pathways. Here, for the first time, we highlighted the relationship between AQP4 and molecular mechanisms involved in PD pathogenesis.
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Affiliation(s)
- Omid Reza Tamtaji
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
| | | | | | - Hamed Jafarpour
- Student Research Committee, Mazandaran University of Medical Science, Sari, Iran
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
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117
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Smith AJ, Duan T, Verkman AS. Aquaporin-4 reduces neuropathology in a mouse model of Alzheimer's disease by remodeling peri-plaque astrocyte structure. Acta Neuropathol Commun 2019; 7:74. [PMID: 31068220 PMCID: PMC6506955 DOI: 10.1186/s40478-019-0728-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 04/23/2019] [Indexed: 01/01/2023] Open
Abstract
Redistribution of the water channel aquaporin-4 (AQP4) away from astrocyte endfeet and into parenchymal processes is a striking histological feature in mouse models of Alzheimer’s disease (AD) and other neurological conditions with prominent astrogliosis. AQP4 redistribution has been proposed to impair bulk Aβ clearance in AD, resulting in increased amyloid deposition in the brain; however, this finding is controversial. Here, we provide evidence in support of a different and novel role of AQP4 in AD. We found that Aqp4 deletion significantly increased amyloid deposition in cerebral cortex of 5xFAD mice, with an increase in the relative number of fibrillar vs. dense core plaques. AQP4 deficient 5xFAD mice also showed a significant reduction in the density of GFAP labeled peri-plaque astrocyte processes. Microglial plaque coverage was also significantly reduced, suggesting astrocyte involvement in organizing the peri-plaque glial response. The alterations in peri-plaque glial structure were accompanied by increased neuronal uptake of Aβ and an increase in the number of dystrophic neurites surrounding plaques. On the basis of these findings, we propose that redistribution of AQP4 into the parenchymal processes facilitates astrocyte structural plasticity and the formation of a reactive glial net around plaques that protects neurons from the deleterious effects of Aβ aggregates. AQP4 redistribution may thus facilitate plaque containment and reduce neuropathology in AD.
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118
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Snuggs JW, Day RE, Bach FC, Conner MT, Bunning RAD, Tryfonidou MA, Le Maitre CL. Aquaporin expression in the human and canine intervertebral disc during maturation and degeneration. JOR Spine 2019; 2:e1049. [PMID: 31463463 PMCID: PMC6686802 DOI: 10.1002/jsp2.1049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 12/13/2022] Open
Abstract
The intervertebral disc (IVD) is a highly hydrated tissue, the rich proteoglycan matrix imbibes water, enabling the disc to withstand compressive loads. During aging and degeneration increased matrix degradation leads to dehydration and loss of function. Aquaporins (AQP) are a family of transmembrane channel proteins that selectively allow the passage of water in and out of cells and are responsible for maintaining water homeostasis in many tissues. Here, the expression of all 13 AQPs at gene and protein level was investigated in human and canine nondegenerate and degenerate IVDs to develop an understanding of the role of AQPs during degeneration. Furthermore, in order to explore the transition of notochordal cells (NCs) towards nucleus pulposus (NP) cells, AQP expression was investigated in canine IVDs enriched in NCs to understand the role of AQPs in IVD maturation. AQP0, 1, 2, 3, 4, 5, 6, 7, and 9 were expressed at gene and protein level in both nondegenerate and degenerate human NP tissue. AQP2 and 7 immunopositivity increased with degeneration in human NP tissue, whereas AQP4 expression decreased with degeneration in a similar way to AQP1 and 5 shown previously. All AQP proteins that were identified in human NP tissue were also expressed in canine NP tissue. AQP2, 5, 6, and 9 were found to localize to vacuole-like membranes and cell membranes in NC cells. In conclusion, AQPs were abundantly expressed in human and canine IVDs. The expression of many AQP isotypes potentially alludes to multifaceted functions related to adaption of NP cells to the conditions they encounter within their microenvironment in health and degeneration. The presence of AQPs within the IVD may suggest an adaptive role for these water channels during the development and maintenance of the healthy, mature IVD.
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Affiliation(s)
- Joseph W. Snuggs
- Biomolecular Sciences Research CentreSheffield Hallam UniversitySheffieldUK
| | - Rebecca E. Day
- Biomolecular Sciences Research CentreSheffield Hallam UniversitySheffieldUK
| | - Frances C. Bach
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
| | - Matthew T. Conner
- Faculty of Science and EngineeringUniversity of WolverhamptonWolverhamptonUK
| | | | - Marianna A. Tryfonidou
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
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119
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Chmelova M, Sucha P, Bochin M, Vorisek I, Pivonkova H, Hermanova Z, Anderova M, Vargova L. The role of aquaporin-4 and transient receptor potential vaniloid isoform 4 channels in the development of cytotoxic edema and associated extracellular diffusion parameter changes. Eur J Neurosci 2019; 50:1685-1699. [PMID: 30633415 DOI: 10.1111/ejn.14338] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/27/2018] [Accepted: 01/04/2019] [Indexed: 11/30/2022]
Abstract
The proper function of the nervous system is dependent on the balance of ions and water between the intracellular and extracellular space (ECS). It has been suggested that the interaction of aquaporin-4 (AQP4) and the transient receptor potential vaniloid isoform 4 (TRPV4) channels play a role in water balance and cell volume regulation, and indirectly, of the ECS volume. Using the real-time iontophoretic method, we studied the changes of the ECS diffusion parameters: ECS volume fraction α (α = ECS volume fraction/total tissue volume) and tortuosity λ (λ2 = free/apparent diffusion coefficient) in mice with a genetic deficiency of AQP4 or TRPV4 channels, and in control animals. The used models of cytotoxic edema included: mild and severe hypotonic stress or oxygen-glucose deprivation (OGD) in situ and terminal ischemia/anoxia in vivo. This study shows that an AQP4 or TRPV4 deficit slows down the ECS volume shrinkage during severe ischemia in vivo. We further demonstrate that a TRPV4 deficit slows down the velocity and attenuates an extent of the ECS volume decrease during OGD treatment in situ. However, in any of the cytotoxic edema models in situ (OGD, mild or severe hypotonic stress), we did not detect any alterations in the cell swelling or volume regulation caused by AQP4 deficiency. Overall, our results indicate that the AQP4 and TRPV4 channels may play a crucial role in severe pathological states associated with their overexpression and enhanced cell swelling. However, detailed interplay between AQP4 and TRPV4 channels requires further studies and additional research.
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Affiliation(s)
- Martina Chmelova
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic.,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - Petra Sucha
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic.,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - Marcel Bochin
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic.,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - Ivan Vorisek
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - Helena Pivonkova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - Zuzana Hermanova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - Miroslava Anderova
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic.,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - Lydia Vargova
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic.,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czech Republic
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120
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Borrachero‐Conejo AI, Saracino E, Natali M, Prescimone F, Karges S, Bonetti S, Nicchia GP, Formaggio F, Caprini M, Zamboni R, Mercuri F, Toffanin S, Muccini M, Benfenati V. Electrical Stimulation by an Organic Transistor Architecture Induces Calcium Signaling in Nonexcitable Brain Cells. Adv Healthc Mater 2019; 8:e1801139. [PMID: 30565894 DOI: 10.1002/adhm.201801139] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/15/2018] [Indexed: 12/31/2022]
Abstract
Organic bioelectronics have a huge potential to generate interfaces and devices for the study of brain functions and for the therapy of brain pathologies. In this context, increasing efforts are needed to develop technologies for monitoring and stimulation of nonexcitable brain cells, called astrocytes. Astroglial calcium signaling plays, indeed, a pivotal role in the physiology and pathophysiology of the brain. Here, the use of transparent organic cell stimulating and sensing transistor (O-CST) architecture, fabricated with N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13), to elicit and monitor intracellular calcium concentration ([Ca2+ ]i ) in primary rat neocortical astrocytes is demonstrated. The transparency of O-CST allows performing calcium imaging experiments, showing that extracellular electrical stimulation of astrocytes induces a drastic increase in [Ca2+ ]i . Pharmacological studies indicate that transient receptor potential (TRP) superfamily are critical mediators of the [Ca2+ ]i increase. Experimental and computational analyses show that [Ca2+ ]i response is enabled by the O-CST device architecture. Noteworthy, the extracellular field application induces a slight but significant increase in the cell volume. Collectively, it is shown that the O-CST is capable of selectively evoking astrocytes [Ca2+ ]i , paving the way to the development of organic bioelectronic devices as glial interfaces to excite and control physiology of non-neuronal brain cells.
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Affiliation(s)
- Ana Isabel Borrachero‐Conejo
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Emanuela Saracino
- Consiglio Nazionale delle Ricerche (CNR) Istituto per la Sintesi Organica e la Fotoreattività (ISOF) Via Gobetti 101 40129 Bologna Italy
| | - Marco Natali
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Federico Prescimone
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Saskia Karges
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Simone Bonetti
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Grazia Paola Nicchia
- Prof. G. P. Nicchia Biotecnologie e Biofarmaceutica University of Bari Aldo Moro Via Orabona 4 70125 Bari Italy
| | - Francesco Formaggio
- Dipartimento di Farmacia e Biotecnologie (FaBit) University of Bologna Via San Donato 15 Bologna 40129 Italy
| | - Marco Caprini
- Dipartimento di Farmacia e Biotecnologie (FaBit) University of Bologna Via San Donato 15 Bologna 40129 Italy
| | - Roberto Zamboni
- Consiglio Nazionale delle Ricerche (CNR) Istituto per la Sintesi Organica e la Fotoreattività (ISOF) Via Gobetti 101 40129 Bologna Italy
| | - Francesco Mercuri
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Stefano Toffanin
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Michele Muccini
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Valentina Benfenati
- Consiglio Nazionale delle Ricerche (CNR) Istituto per la Sintesi Organica e la Fotoreattività (ISOF) Via Gobetti 101 40129 Bologna Italy
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121
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Min R, van der Knaap MS. Genetic defects disrupting glial ion and water homeostasis in the brain. Brain Pathol 2019; 28:372-387. [PMID: 29740942 PMCID: PMC8028498 DOI: 10.1111/bpa.12602] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/02/2018] [Indexed: 12/23/2022] Open
Abstract
Electrical activity of neurons in the brain, caused by the movement of ions between intracellular and extracellular compartments, is the basis of all our thoughts and actions. Maintaining the correct ionic concentration gradients is therefore crucial for brain functioning. Ion fluxes are accompanied by the displacement of osmotically obliged water. Since even minor brain swelling leads to severe brain damage and even death, brain ion and water movement has to be tightly regulated. Glial cells, in particular astrocytes, play a key role in ion and water homeostasis. They are endowed with specific channels, pumps and carriers to regulate ion and water flow. Glial cells form a large panglial syncytium to aid the uptake and dispersal of ions and water, and make extensive contacts with brain fluid barriers for disposal of excess ions and water. Genetic defects in glial proteins involved in ion and water homeostasis disrupt brain functioning, thereby leading to neurological diseases. Since white matter edema is often a hallmark disease feature, many of these diseases are characterized as leukodystrophies. In this review we summarize our current understanding of inherited glial diseases characterized by disturbed brain ion and water homeostasis by integrating findings from MRI, genetics, neuropathology and animal models for disease. We discuss how mutations in different glial proteins lead to disease, and highlight the similarities and differences between these diseases. To come to effective therapies for this group of diseases, a better mechanistic understanding of how glial cells shape ion and water movement in the brain is crucial.
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Affiliation(s)
- Rogier Min
- Department of Child Neurology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.,Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - Marjo S van der Knaap
- Department of Child Neurology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
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122
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Bursting at the Seams: Molecular Mechanisms Mediating Astrocyte Swelling. Int J Mol Sci 2019; 20:ijms20020330. [PMID: 30650535 PMCID: PMC6359623 DOI: 10.3390/ijms20020330] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/10/2019] [Accepted: 01/11/2019] [Indexed: 01/31/2023] Open
Abstract
Brain swelling is one of the most robust predictors of outcome following brain injury, including ischemic, traumatic, hemorrhagic, metabolic or other injury. Depending on the specific type of insult, brain swelling can arise from the combined space-occupying effects of extravasated blood, extracellular edema fluid, cellular swelling, vascular engorgement and hydrocephalus. Of these, arguably the least well appreciated is cellular swelling. Here, we explore current knowledge regarding swelling of astrocytes, the most abundant cell type in the brain, and the one most likely to contribute to pathological brain swelling. We review the major molecular mechanisms identified to date that contribute to or mitigate astrocyte swelling via ion transport, and we touch upon the implications of astrocyte swelling in health and disease.
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123
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Morrison HW, Filosa JA. Stroke and the neurovascular unit: glial cells, sex differences, and hypertension. Am J Physiol Cell Physiol 2019; 316:C325-C339. [PMID: 30601672 DOI: 10.1152/ajpcell.00333.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A functional neurovascular unit (NVU) is central to meeting the brain's dynamic metabolic needs. Poststroke damage to the NVU within the ipsilateral hemisphere ranges from cell dysfunction to complete cell loss. Thus, understanding poststroke cell-cell communication within the NVU is of critical importance. Loss of coordinated NVU function exacerbates ischemic injury. However, particular cells of the NVU (e.g., astrocytes) and those with ancillary roles (e.g., microglia) also contribute to repair mechanisms. Epidemiological studies support the notion that infarct size and recovery outcomes are heterogeneous and greatly influenced by modifiable and nonmodifiable factors such as sex and the co-morbid condition common to stroke: hypertension. The mechanisms whereby sex and hypertension modulate NVU function are explored, to some extent, in preclinical laboratory studies. We present a review of the NVU in the context of ischemic stroke with a focus on glial contributions to NVU function and dysfunction. We explore the impact of sex and hypertension as modifiable and nonmodifiable risk factors and the underlying cellular mechanisms that may underlie heterogeneous stroke outcomes. Most of the preclinical investigative studies of poststroke NVU dysfunction are carried out primarily in male stroke models lacking underlying co-morbid conditions, which is very different from the human condition. As such, the evolution of translational medicine to target the NVU for improved stroke outcomes remains elusive; however, it is attainable with further research.
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Roles of volume-regulatory anion channels, VSOR and Maxi-Cl, in apoptosis, cisplatin resistance, necrosis, ischemic cell death, stroke and myocardial infarction. CURRENT TOPICS IN MEMBRANES 2019; 83:205-283. [DOI: 10.1016/bs.ctm.2019.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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125
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Diaz JR, Kim KJ, Brands MW, Filosa JA. Augmented astrocyte microdomain Ca 2+ dynamics and parenchymal arteriole tone in angiotensin II-infused hypertensive mice. Glia 2018; 67:551-565. [PMID: 30506941 DOI: 10.1002/glia.23564] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 10/22/2018] [Accepted: 10/22/2018] [Indexed: 11/09/2022]
Abstract
Hypertension is an important contributor to cognitive decline but the underlying mechanisms are unknown. Although much focus has been placed on the effect of hypertension on vascular function, less is understood of its effects on nonvascular cells. Because astrocytes and parenchymal arterioles (PA) form a functional unit (neurovascular unit), we tested the hypothesis that hypertension-induced changes in PA tone concomitantly increases astrocyte Ca2+ . We used cortical brain slices from 8-week-old mice to measure myogenic responses from pressurized and perfused PA. Chronic hypertension was induced in mice by 28-day angiotensin II (Ang II) infusion; PA resting tone and myogenic responses increased significantly. In addition, chronic hypertension significantly increased spontaneous Ca2+ events within astrocyte microdomains (MD). Similarly, a significant increase in astrocyte Ca2+ was observed during PA myogenic responses supporting enhanced vessel-to-astrocyte signaling. The transient potential receptor vanilloid 4 (TRPV4) channel, expressed in astrocyte processes in contact with blood vessels, namely endfeet, respond to hemodynamic stimuli such as increased pressure/flow. Supporting a role for TRPV4 channels in aberrant astrocyte Ca2+ dynamics in hypertension, cortical astrocytes from hypertensive mice showed augmented TRPV4 channel expression, currents and Ca2+ responses to the selective channel agonist GSK1016790A. In addition, pharmacological TRPV4 channel blockade or genetic deletion abrogated enhanced hypertension-induced increases in PA tone. Together, these data suggest chronic hypertension increases PA tone and Ca2+ events within astrocytes MD. We conclude that aberrant Ca2+ events in astrocyte constitute an early event toward the progression of cognitive decline.
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Affiliation(s)
| | - Ki Jung Kim
- Department of Physiology, Augusta University, Augusta, Georgia
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126
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Prevarskaya N, Skryma R, Shuba Y. Ion Channels in Cancer: Are Cancer Hallmarks Oncochannelopathies? Physiol Rev 2018; 98:559-621. [PMID: 29412049 DOI: 10.1152/physrev.00044.2016] [Citation(s) in RCA: 277] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Genomic instability is a primary cause and fundamental feature of human cancer. However, all cancer cell genotypes generally translate into several common pathophysiological features, often referred to as cancer hallmarks. Although nowadays the catalog of cancer hallmarks is quite broad, the most common and obvious of them are 1) uncontrolled proliferation, 2) resistance to programmed cell death (apoptosis), 3) tissue invasion and metastasis, and 4) sustained angiogenesis. Among the genes affected by cancer, those encoding ion channels are present. Membrane proteins responsible for signaling within cell and among cells, for coupling of extracellular events with intracellular responses, and for maintaining intracellular ionic homeostasis ion channels contribute to various extents to pathophysiological features of each cancer hallmark. Moreover, tight association of these hallmarks with ion channel dysfunction gives a good reason to classify them as special type of channelopathies, namely oncochannelopathies. Although the relation of cancer hallmarks to ion channel dysfunction differs from classical definition of channelopathies, as disease states causally linked with inherited mutations of ion channel genes that alter channel's biophysical properties, in a broader context of the disease state, to which pathogenesis ion channels essentially contribute, such classification seems absolutely appropriate. In this review the authors provide arguments to substantiate such point of view.
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Affiliation(s)
- Natalia Prevarskaya
- INSERM U-1003, Equipe Labellisée par la Ligue Nationale contre le Cancer et LABEX, Université Lille1 , Villeneuve d'Ascq , France ; Bogomoletz Institute of Physiology and International Center of Molecular Physiology, NASU, Kyiv-24, Ukraine
| | - Roman Skryma
- INSERM U-1003, Equipe Labellisée par la Ligue Nationale contre le Cancer et LABEX, Université Lille1 , Villeneuve d'Ascq , France ; Bogomoletz Institute of Physiology and International Center of Molecular Physiology, NASU, Kyiv-24, Ukraine
| | - Yaroslav Shuba
- INSERM U-1003, Equipe Labellisée par la Ligue Nationale contre le Cancer et LABEX, Université Lille1 , Villeneuve d'Ascq , France ; Bogomoletz Institute of Physiology and International Center of Molecular Physiology, NASU, Kyiv-24, Ukraine
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127
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Pivonkova H, Hermanova Z, Kirdajova D, Awadova T, Malinsky J, Valihrach L, Zucha D, Kubista M, Galisova A, Jirak D, Anderova M. The Contribution of TRPV4 Channels to Astrocyte Volume Regulation and Brain Edema Formation. Neuroscience 2018; 394:127-143. [PMID: 30367945 DOI: 10.1016/j.neuroscience.2018.10.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 10/12/2018] [Accepted: 10/15/2018] [Indexed: 12/01/2022]
Abstract
Transient receptor potential vanilloid type 4 (TRPV4) channels are involved in astrocyte volume regulation; however, only limited data exist about its mechanism in astrocytes in situ. We performed middle cerebral artery occlusion in adult mice, where we found twice larger edema 1 day after the insult in trpv4-/- mice compared to the controls, which was quantified using magnetic resonance imaging. This result suggests disrupted volume regulation in the brain cells in trpv4-/- mice leading to increased edema formation. The aim of our study was to elucidate whether TRPV4 channel-based volume regulation occurs in astrocytes in situ and whether the disrupted volume regulation in trpv4-/- mice might lead to higher edema formation after brain ischemia. For our experiments, we used trpv4-/- mice crossed with transgenic mice expressing enhanced green fluorescent protein (EGFP) under the control of the glial fibrillary acidic protein promoter, which leads to astrocyte visualization by EGFP expression. For quantification of astrocyte volume changes, we used two-dimensional (2D) and three-dimensional (3D) morphometrical approaches and a quantification algorithm based on fluorescence intensity changes during volume alterations induced by hypotonicity or by oxygen-glucose deprivation. In contrast to in vitro experiments, we found little evidence of the contribution of TRPV4 channels to volume regulation in astrocytes in situ in adult mice. Moreover, we only found a rare expression of TRPV4 channels in adult mouse astrocytes. Our data suggest that TRPV4 channels are not involved in astrocyte volume regulation in situ; however, they play a protective role during the ischemia-induced brain edema formation.
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Affiliation(s)
- Helena Pivonkova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Hermanova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic
| | - Denisa Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic
| | - Thuraya Awadova
- Department of Microscopy, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Malinsky
- Department of Microscopy, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic
| | - Lukas Valihrach
- Laboratory of Gene Expression, Institute of Biotechnology, Czech Academy of Sciences, Prague, Czech Republic
| | - Daniel Zucha
- Laboratory of Gene Expression, Institute of Biotechnology, Czech Academy of Sciences, Prague, Czech Republic
| | - Mikael Kubista
- Laboratory of Gene Expression, Institute of Biotechnology, Czech Academy of Sciences, Prague, Czech Republic; TATAA Biocenter AB, Gothenburg 411 03, Sweden
| | - Andrea Galisova
- Department of Radiodiagnostic and Interventional Radiology, Institute of Clinical and Experimental Medicine, Prague, Czech Republic
| | - Daniel Jirak
- Department of Radiodiagnostic and Interventional Radiology, Institute of Clinical and Experimental Medicine, Prague, Czech Republic; Institute of Biophysics and Informatics, 1st Medicine Faculty, Charles University, Prague, Czech Republic
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic; Department of Neuroscience, 2nd Medical Faculty, Charles University, Prague, Czech Republic.
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128
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Cornillot M, Giacco V, Hamilton NB. The role of TRP channels in white matter function and ischaemia. Neurosci Lett 2018; 690:202-209. [PMID: 30366011 DOI: 10.1016/j.neulet.2018.10.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/09/2018] [Accepted: 10/18/2018] [Indexed: 01/15/2023]
Abstract
Transient receptor potential (TRP) proteins are a large family of tetrameric non-selective cation channels that are widely expressed in the grey and white matter of the CNS, and are increasingly considered as potential therapeutic targets in brain disorders. Here we briefly review the evidence for TRP channel expression in glial cells and their possible role in both glial cell physiology and stroke. Despite their contribution to important functions, our understanding of the roles of TRP channels in glia is still in its infancy. The evidence reviewed here indicates that further investigation is needed to determine whether TRP channel inhibition can decrease damage or increase repair in stroke and other diseases affecting the white matter.
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Affiliation(s)
- Marion Cornillot
- Wolfson Centre for Age Related Disease, King's College London, Guy's Campus, London, SE1 1UL, United Kingdom
| | - Vincenzo Giacco
- Wolfson Centre for Age Related Disease, King's College London, Guy's Campus, London, SE1 1UL, United Kingdom
| | - Nicola B Hamilton
- Wolfson Centre for Age Related Disease, King's College London, Guy's Campus, London, SE1 1UL, United Kingdom.
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129
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Halsey AM, Conner AC, Bill RM, Logan A, Ahmed Z. Aquaporins and Their Regulation after Spinal Cord Injury. Cells 2018; 7:E174. [PMID: 30340399 PMCID: PMC6210264 DOI: 10.3390/cells7100174] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/13/2018] [Accepted: 10/15/2018] [Indexed: 11/16/2022] Open
Abstract
After injury to the spinal cord, edema contributes to the underlying detrimental pathophysiological outcomes that lead to worsening of function. Several related membrane proteins called aquaporins (AQPs) regulate water movement in fluid transporting tissues including the spinal cord. Within the cord, AQP1, 4 and 9 contribute to spinal cord injury (SCI)-induced edema. AQP1, 4 and 9 are expressed in a variety of cells including astrocytes, neurons, ependymal cells, and endothelial cells. This review discusses some of the recent findings of the involvement of AQP in SCI and highlights the need for further study of these proteins to develop effective therapies to counteract the negative effects of SCI-induced edema.
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Affiliation(s)
- Andrea M Halsey
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Alex C Conner
- Institute of Clinical Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Roslyn M Bill
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK.
| | - Ann Logan
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Zubair Ahmed
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, B15 2TT, UK.
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130
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Sanglard LP, Nascimento M, Moriel P, Sommer J, Ashwell M, Poore MH, Duarte MDS, Serão NVL. Impact of energy restriction during late gestation on the muscle and blood transcriptome of beef calves after preconditioning. BMC Genomics 2018; 19:702. [PMID: 30253751 PMCID: PMC6156876 DOI: 10.1186/s12864-018-5089-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 09/19/2018] [Indexed: 02/03/2023] Open
Abstract
Background Maternal nutrition has been highlighted as one of the main factors affecting intra-uterine environment. The increase in nutritional requirements by beef cows during late gestation can cause nutritional deficiency in the fetus and impact the fetal regulation of genes associated with myogenesis and immune response. Methods Forty days before the expected calving date, cows were assigned to one of two diets: 100% (control) or 70% (restricted group) of the daily energy requirement. Muscle samples were collected from 12 heifers and 12 steers, and blood samples were collected from 12 steers. The objective of this work was to identify and to assess the biological relevance of differentially expressed genes (DEG) in the skeletal muscle and blood of beef calves born from cows that experienced [or not] a 30% energy restriction during the last 40 days of gestation. Results A total of 160, 164, and 346 DEG (q-value< 0.05) were identified in the skeletal muscle for the effects of diet, sex, and diet-by-sex interaction, respectively. For blood, 452, 1392, and 155 DEG were identified for the effects of diet, time, and diet-by-time interaction, respectively. For skeletal muscle, results based on diet identified genes involved in muscle metabolism. In muscle, from the 10 most DEG down-regulated in the energy-restricted group (REST), we identified 5 genes associated with muscle metabolism and development: SLCO3A1, ATP6V0D1, SLC2A1, GPC4, and RASD2. In blood, among the 10 most DEG, we found genes related to response to stress up-regulated in the REST after weaning, such as SOD3 and INO80D, and to immune response down-regulated in the REST after vaccination, such as OASL, KLRF1, and LOC104968634. Conclusion In conclusion, maternal energy restriction during late gestation may limit the expression of genes in the muscle and increase expression in the blood of calves. In addition, enrichment analysis showed that a short-term maternal energy restriction during pregnancy affects the expression of genes related to energy metabolism and muscle contraction, and immunity and stress response in the blood. Therefore, alterations in the intra-uterine environment can modify prenatal development with lasting consequences to adult life. Electronic supplementary material The online version of this article (10.1186/s12864-018-5089-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Leticia P Sanglard
- Department of Animal Science, Iowa State University, Ames, 50011, USA.,Department of Animal Science, North Carolina State University, Raleigh, 27695, USA
| | - Moysés Nascimento
- Department of Animal Science, North Carolina State University, Raleigh, 27695, USA.,Department of Statistics, Universidade Federal de Viçosa, Viçosa, 36570-000, Brazil
| | - Philipe Moriel
- Range Cattle Research and Education Center, University of Florida, Ona, Florida, 33865, USA
| | - Jeffrey Sommer
- Department of Animal Science, North Carolina State University, Raleigh, 27695, USA
| | - Melissa Ashwell
- Department of Animal Science, North Carolina State University, Raleigh, 27695, USA
| | - Matthew H Poore
- Department of Animal Science, North Carolina State University, Raleigh, 27695, USA
| | - Márcio de S Duarte
- Department of Animal Science, Universidade Federal de Viçosa, Viçosa, 36570-000, Brazil.,Instituto Nacional de Ciência e Tecnologia - Ciência Animal, Viçosa, 36570-000, Brazil
| | - Nick V L Serão
- Department of Animal Science, Iowa State University, Ames, 50011, USA. .,Department of Animal Science, North Carolina State University, Raleigh, 27695, USA.
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131
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Wilson CS, Mongin AA. Cell Volume Control in Healthy Brain and Neuropathologies. CURRENT TOPICS IN MEMBRANES 2018; 81:385-455. [PMID: 30243438 DOI: 10.1016/bs.ctm.2018.07.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Regulation of cellular volume is a critical homeostatic process that is intimately linked to ionic and osmotic balance in the brain tissue. Because the brain is encased in the rigid skull and has a very complex cellular architecture, even minute changes in the volume of extracellular and intracellular compartments have a very strong impact on tissue excitability and function. The failure of cell volume control is a major feature of several neuropathologies, such as hyponatremia, stroke, epilepsy, hyperammonemia, and others. There is strong evidence that such dysregulation, especially uncontrolled cell swelling, plays a major role in adverse pathological outcomes. To protect themselves, brain cells utilize a variety of mechanisms to maintain their optimal volume, primarily by releasing or taking in ions and small organic molecules through diverse volume-sensitive ion channels and transporters. In principle, the mechanisms of cell volume regulation are not unique to the brain and share many commonalities with other tissues. However, because ions and some organic osmolytes (e.g., major amino acid neurotransmitters) have a strong impact on neuronal excitability, cell volume regulation in the brain is a surprisingly treacherous process, which may cause more harm than good. This topical review covers the established and emerging information in this rapidly developing area of physiology.
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Affiliation(s)
- Corinne S Wilson
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
| | - Alexander A Mongin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States; Department of Biophysics and Functional Diagnostics, Siberian State Medical University, Tomsk, Russian Federation
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132
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Jin S, Long Z, Wang W, Jiang B. Hyponatremia in neuromyelitis optica spectrum disorders: Literature review. Acta Neurol Scand 2018; 138:4-11. [PMID: 29654708 DOI: 10.1111/ane.12938] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2018] [Indexed: 02/03/2023]
Abstract
Hyponatremia is a potentially serious electrolyte abnormality observed in neuromyelitis optica spectrum disorders (NMOSDs), and its most common cause is syndrome of inappropriate antidiuretic hormone secretion (SIADH). Another potential cause of hyponatremia is cerebral salt-wasting syndrome (CSWS), although CSWS has not previously been reported in NMOSDs. Accurate and early differentiation between SIADH and CSWS is difficult. However, the two conditions have important implications for the selection of therapy. Here, we describe two patients with aquaporin-4 antibody (AQP4-Ab)-positive NMOSDs who developed hyponatremia as a result of CSWS and SIADH, respectively. Additionally, we review all previously reported studies of hyponatremia in patients with NMOSDs and propose several potential pathophysiological mechanisms of hyponatremia. In conclusion, NMOSDs accompanied by hyponatremia are not actually rare, but have previously been given little attention. Furthermore, SIADH should not be the only consideration, before the exclusion of rare but significant CSWS.
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Affiliation(s)
- S. Jin
- Department of Neurology; The Second Xiangya Hospital; Central South University; Changsha China
| | - Z. Long
- Department of Neurology; The Second Xiangya Hospital; Central South University; Changsha China
| | - W. Wang
- Department of Neurology; The Second Xiangya Hospital; Central South University; Changsha China
| | - B. Jiang
- Department of Neurology; The Second Xiangya Hospital; Central South University; Changsha China
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Formaggio F, Saracino E, Mola MG, Rao SB, Amiry-Moghaddam M, Muccini M, Zamboni R, Nicchia GP, Caprini M, Benfenati V. LRRC8A is essential for swelling-activated chloride current and for regulatory volume decrease in astrocytes. FASEB J 2018; 33:101-113. [PMID: 29957062 DOI: 10.1096/fj.201701397rr] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Consolidated evidence indicates that astroglial cells are critical in the homeostatic regulation of cellular volume by means of ion channels and aquaporin-4. Volume-regulated anion channel (VRAC) is the chloride channel that is activated upon cell swelling and critically contributes to cell volume regulation in astrocytes. The molecular identity of VRAC has been recently defined, revealing that it belongs to the leucine-rich repeat-containing 8 (LRRC8) protein family. However, there is a lack of evidence demonstrating that LRRC8A underpins VRAC currents in astrocyte. Nonetheless, direct evidence of the role of LRRC8A in astrocytic regulatory volume decrease remains to be proved. Here, we aim to bridge this gap in knowledge by combining RNA interference specific for LRRC8A with patch-clamp analyses and a water-permeability assay. We demonstrated that LRRC8A molecular expression is essential for swelling-activated chloride current via VRAC in primary-cultured cortical astrocytes. The knockdown of LRRC8A with a specific short interference RNA abolished the recovery of the cell volume after swelling induced by hypotonic challenge. In addition, immunoblotting, immunofluorescence, confocal imaging, and immunogold electron microscopy demonstrated that LRRC8A is expressed in the plasma membrane of primary cortical astrocytes and in situ in astrocytes at the perivascular interface with endothelial cells. Collectively, our results suggest that LRRC8A is an essential subunit of VRAC and a key factor for astroglial volume homeostasis.-Formaggio, F., Saracino, E., Mola, M. G., Rao, S. B., Amiry-Moghaddam, M., Muccini, M., Zamboni, R., Nicchia, G. P., Caprini, M., Benfenati, V. LRRC8A is essential for swelling-activated chloride current and for regulatory volume decrease in astrocytes.
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Affiliation(s)
- Francesco Formaggio
- Laboratory of Human and General Physiology, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.,Institute for the Study of Nanostructured Materials, National Research Council of Italy, Bologna, Italy
| | - Emanuela Saracino
- Institute for the Organic Synthesis and Photoreactivity, National Research Council of Italy, Bologna, Italy
| | - Maria Grazia Mola
- Department of Bioscience, Biotechnologies, and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari Aldo Moro, Bari, Italy
| | - Shreyas Balachandra Rao
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Mahmood Amiry-Moghaddam
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Michele Muccini
- Institute for the Study of Nanostructured Materials, National Research Council of Italy, Bologna, Italy
| | - Roberto Zamboni
- Institute for the Organic Synthesis and Photoreactivity, National Research Council of Italy, Bologna, Italy
| | - Grazia Paola Nicchia
- Department of Bioscience, Biotechnologies, and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari Aldo Moro, Bari, Italy.,Department of Neuroscience, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York, USA
| | - Marco Caprini
- Laboratory of Human and General Physiology, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.,Institute for the Study of Nanostructured Materials, National Research Council of Italy, Bologna, Italy
| | - Valentina Benfenati
- Institute for the Study of Nanostructured Materials, National Research Council of Italy, Bologna, Italy.,Institute for the Organic Synthesis and Photoreactivity, National Research Council of Italy, Bologna, Italy
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Ischemic Brain Injury Leads to Brain Edema via Hyperthermia-Induced TRPV4 Activation. J Neurosci 2018; 38:5700-5709. [PMID: 29793978 DOI: 10.1523/jneurosci.2888-17.2018] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 04/26/2018] [Accepted: 05/03/2018] [Indexed: 01/27/2023] Open
Abstract
Brain edema is characterized by an increase in net brain water content, which results in an increase in brain volume. Although brain edema is associated with a high fatality rate, the cellular and molecular processes of edema remain largely unclear. Here, we developed an in vitro model of ischemic stroke-induced edema in which male mouse brain slices were treated with oxygen-glucose deprivation (OGD) to mimic ischemia. We continuously measured the cross-sectional area of the brain slice for 150 min under macroscopic microscopy, finding that OGD induces swelling of brain slices. OGD-induced swelling was prevented by pharmacologically blocking or genetically knocking out the transient receptor potential vanilloid 4 (TRPV4), a member of the thermosensitive TRP channel family. Because TRPV4 is activated at around body temperature and its activation is enhanced by heating, we next elevated the temperature of the perfusate in the recording chamber, finding that hyperthermia induces swelling via TRPV4 activation. Furthermore, using the temperature-dependent fluorescence lifetime of a fluorescent-thermosensitive probe, we confirmed that OGD treatment increases the temperature of brain slices through the activation of glutamate receptors. Finally, we found that brain edema following traumatic brain injury was suppressed in TRPV4-deficient male mice in vivo Thus, our study proposes a novel mechanism: hyperthermia activates TRPV4 and induces brain edema after ischemia.SIGNIFICANCE STATEMENT Brain edema is characterized by an increase in net brain water content, which results in an increase in brain volume. Although brain edema is associated with a high fatality rate, the cellular and molecular processes of edema remain unclear. Here, we developed an in vitro model of ischemic stroke-induced edema in which mouse brain slices were treated with oxygen-glucose deprivation. Using this system, we showed that the increase in brain temperature and the following activation of the thermosensitive cation channel TRPV4 (transient receptor potential vanilloid 4) are involved in the pathology of edema. Finally, we confirmed that TRPV4 is involved in brain edema in vivo using TRPV4-deficient mice, concluding that hyperthermia activates TRPV4 and induces brain edema after ischemia.
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135
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Preston D, Simpson S, Halm D, Hochstetler A, Schwerk C, Schroten H, Blazer-Yost BL. Activation of TRPV4 stimulates transepithelial ion flux in a porcine choroid plexus cell line. Am J Physiol Cell Physiol 2018; 315:C357-C366. [PMID: 29791207 DOI: 10.1152/ajpcell.00312.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The choroid plexus (CP) epithelium plays a major role in the production of cerebrospinal fluid (CSF). A polarized cell line, the porcine CP-Riems (PCP-R) line, which exhibits many of the characteristics of the native epithelium, was used to study the effect of activation of the transient receptor potential vanilloid 4 (TRPV4) cation channel found in the PCP-R cells as well as in the native epithelium. Ussing-style electrophysiological experiments showed that activation of TRPV4 with a specific agonist, GSK1016790A, resulted in an immediate increase in both transepithelial ion flux and conductance. These changes were inhibited by either of two distinct antagonists, HC067047 or RN1734. The change in conductance was reversible and did not involve disruption of epithelial junctional complexes. Activation of TRPV4 results in Ca2+ influx, therefore, we examined whether the electrophysiological changes were the result of secondary activation of Ca2+-sensitive channels. PCP-R cells contain two Ca2+-activated K+ channels, the small conductance 2 (SK2) and the intermediate conductance (IK) channels. Based on inhibitor studies, the former is not involved in the TRPV4-mediated electrophysiological changes whereas one of the three isoforms of the IK channel (KCNN4c) may play a role in the apical secretion of K+. Blocking the activity of this IK isoform with TRAM34 inhibited the TRPV4-mediated change in net transepithelial ion flux and the increased conductance. These studies implicate TRPV4 as a hub protein in the control of CSF production through stimulation by multiple effectors resulting in transepithelial ion and subsequent water movement.
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Affiliation(s)
- Daniel Preston
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
| | - Stefanie Simpson
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
| | - Dan Halm
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University , Dayton, Ohio
| | - Alexandra Hochstetler
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
| | - Christian Schwerk
- Mannheim Medical Faculty, University of Heidelberg, Children's Hospital , Mannheim , Germany
| | - Horst Schroten
- Mannheim Medical Faculty, University of Heidelberg, Children's Hospital , Mannheim , Germany
| | - Bonnie L Blazer-Yost
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
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136
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Agbani EO, Williams CM, Li Y, van den Bosch MT, Moore SF, Mauroux A, Hodgson L, Verkman AS, Hers I, Poole AW. Aquaporin-1 regulates platelet procoagulant membrane dynamics and in vivo thrombosis. JCI Insight 2018; 3:99062. [PMID: 29769447 PMCID: PMC6012506 DOI: 10.1172/jci.insight.99062] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 04/12/2018] [Indexed: 01/02/2023] Open
Abstract
In response to collagen stimulation, platelets use a coordinated system of fluid entry to undergo membrane ballooning, procoagulant spreading, and microvesiculation. We hypothesized that water entry was mediated by the water channel aquaporin-1 (AQP1) and aimed to determine its role in the platelet procoagulant response and thrombosis. We established that human and mouse platelets express AQP1 and localize to internal tubular membrane structures. However, deletion of AQP1 had minimal effects on collagen-induced platelet granule secretion, aggregation, or membrane ballooning. Conversely, procoagulant spreading, microvesiculation, phosphatidylserine exposure, and clot formation time were significantly diminished. Furthermore, in vivo thrombus formation after FeCl3 injury to carotid arteries was also markedly suppressed in AQP1-null mice, but hemostasis after tail bleeding remained normal. The mechanism involves an AQP1-mediated rapid membrane stretching during procoagulant spreading but not ballooning, leading to calcium entry through mechanosensitive cation channels and a full procoagulant response. We conclude that AQP1 is a major regulator of the platelet procoagulant response, able to modulate coagulation after injury or pathologic stimuli without affecting other platelet functional responses or normal hemostasis. Clinically effective AQP1 inhibitors may therefore represent a novel class of antiprocoagulant antithrombotics. AQP1 controls platelet procoagulant response and modulates coagulation after injury or pathologic stimuli without affecting other platelet functional responses or normal hemostasis.
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Affiliation(s)
- Ejaife O Agbani
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Christopher M Williams
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Yong Li
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Marion Tj van den Bosch
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Samantha F Moore
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Adele Mauroux
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Lorna Hodgson
- Wolfson Bioimaging Facility, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Alan S Verkman
- Departments of Medicine and Physiology, University of California San Francisco, San Francisco, California, USA
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
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137
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Kumar H, Lee SH, Kim KT, Zeng X, Han I. TRPV4: a Sensor for Homeostasis and Pathological Events in the CNS. Mol Neurobiol 2018; 55:8695-8708. [PMID: 29582401 DOI: 10.1007/s12035-018-0998-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 03/07/2018] [Indexed: 01/22/2023]
Abstract
Transient receptor potential vanilloid type 4 (TRPV4) was originally described as a calcium-permeable nonselective cation channel. TRPV4 is now recognized as a polymodal ionotropic receptor: it is a broadly expressed, nonselective cation channel (permeable to calcium, potassium, magnesium, and sodium) that plays an important role in a multitude of physiological processes. TRPV4 is involved in maintaining homeostasis, serves as an osmosensor and thermosensor, can be activated directly by endogenous or exogenous chemical stimuli, and can be activated or sensitized indirectly via intracellular signaling pathways. Additionally, TRPV4 is upregulated in a variety of pathological conditions. In this review, we focus on the role of TRPV4 in mediating homeostasis and pathological events in the central nervous system (CNS). This review is composed of three parts. Section 1 describes the role of TRPV4 in maintaining homeostatic processes, including the volume of body water, ionic concentrations, volume, and the temperature. Section 2 describes the effects of activation and inhibition of TRPV4 in the CNS. Section 3 focuses on the role of TRPV4 during pathological events in CNS.
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Affiliation(s)
- Hemant Kumar
- Department of Neurosurgery, CHA University, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, 13496, Republic of Korea
| | - Soo-Hong Lee
- Department of Biomedical Science, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Kyoung-Tae Kim
- Department of Neurosurgery, Kyungpook National University Hospital, 130, Dongdeok-ro, Jung-gu, Daegu, 41944, Republic of Korea
| | - Xiang Zeng
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China.
| | - Inbo Han
- Department of Neurosurgery, CHA University, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, 13496, Republic of Korea.
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138
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Zhang Y, Guan Y, Zhang T, Yuan C, Liu Y, Wang Z. Adult exposure to bisphenol A in rare minnow Gobiocypris rarus reduces sperm quality with disruption of testicular aquaporins. CHEMOSPHERE 2018; 193:365-375. [PMID: 29149713 DOI: 10.1016/j.chemosphere.2017.11.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 11/07/2017] [Accepted: 11/07/2017] [Indexed: 06/07/2023]
Abstract
Bisphenol A (BPA) is an endocrine disrupter which has adverse effects on male reproduction. Aquaporins (AQPs), well known water-selective channels, play important roles in spermatogenesis and sperm functions. However, whether AQPs participate in the process that BPA induces abnormal sperms has not been investigated to date. In the present study, adult male rare minnows Gobiocypris rarus were exposed to environmentally relevant concentrations BPA (15 and 225 μg/L) for 1, 2 and 3 weeks. Results showed that BPA exposure disrupted sperm motility, increased the percentage of abnormal sperm cells, and decreased sperm tolerance to hypotonic solution and sperm fertilization capacity. Meanwhile, protein levels of AQPs were up-regulated, and their distribution in the testis was abnormal following BPA exposure. The following chromatin immune coprecipitation showed that BPA could regulate aqp3 and 8 expression through the ERE in their 5'-flanking region. The present study demonstrated that BPA could decrease the sperm quality in rare minnow, and AQP3 and 8 might play significant roles in this process.
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Affiliation(s)
- Yingying Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China; College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Yongjing Guan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ting Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Cong Yuan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yan Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Zaizhao Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China.
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139
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Pizzoni A, López González M, Di Giusto G, Rivarola V, Capurro C, Ford P. AQP2 can modulate the pattern of Ca
2+
transients induced by store‐operated Ca
2+
entry under TRPV4 activation. J Cell Biochem 2018; 119:4120-4133. [DOI: 10.1002/jcb.26612] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 12/07/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Alejandro Pizzoni
- Laboratorio de Biomembranas, Facultad de Medicina, Departamento de Ciencias FisiológicasUniversidad de Buenos AiresBuenos AiresArgentina
- CONICET‐Universidad de Buenos AiresInstituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO)Buenos AiresArgentina
| | - Macarena López González
- Laboratorio de Biomembranas, Facultad de Medicina, Departamento de Ciencias FisiológicasUniversidad de Buenos AiresBuenos AiresArgentina
| | - Gisela Di Giusto
- Laboratorio de Biomembranas, Facultad de Medicina, Departamento de Ciencias FisiológicasUniversidad de Buenos AiresBuenos AiresArgentina
- CONICET‐Universidad de Buenos AiresInstituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO)Buenos AiresArgentina
| | - Valeria Rivarola
- Laboratorio de Biomembranas, Facultad de Medicina, Departamento de Ciencias FisiológicasUniversidad de Buenos AiresBuenos AiresArgentina
- CONICET‐Universidad de Buenos AiresInstituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO)Buenos AiresArgentina
| | - Claudia Capurro
- Laboratorio de Biomembranas, Facultad de Medicina, Departamento de Ciencias FisiológicasUniversidad de Buenos AiresBuenos AiresArgentina
- CONICET‐Universidad de Buenos AiresInstituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO)Buenos AiresArgentina
| | - Paula Ford
- Laboratorio de Biomembranas, Facultad de Medicina, Departamento de Ciencias FisiológicasUniversidad de Buenos AiresBuenos AiresArgentina
- CONICET‐Universidad de Buenos AiresInstituto de Fisiología y Biofísica “Bernardo Houssay” (IFIBIO)Buenos AiresArgentina
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140
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Hayao K, Tamaki H, Nakagawa K, Tamakoshi K, Takahashi H, Yotani K, Ogita F, Yamamoto N, Onishi H. Effects of Streptomycin Administration on Increases in Skeletal Muscle Fiber Permeability and Size Following Eccentric Muscle Contractions. Anat Rec (Hoboken) 2018; 301:1096-1102. [PMID: 29314717 DOI: 10.1002/ar.23770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/17/2017] [Accepted: 10/24/2017] [Indexed: 01/01/2023]
Abstract
The purpose of this study was to investigate the preventive effect of streptomycin (Str) administration on changes in membrane permeability and the histomorphological characteristics of damaged muscle fibers following eccentric contraction (ECC ). Eighteen 7-week-old male Fischer 344 rats were randomly assigned to three groups: control (Cont), ECC, and ECC with Str (ECC + Str). The tibialis anterior (TA) muscles in both ECC groups were stimulated electrically and exhibited ECC. Evans blue dye (EBD), a marker of muscle fiber damage associated with increased membrane permeability, was injected 24 hr before TA muscle sampling. The number of EBD-positive fibers, muscle fiber cross-sectional area (CSA), and roundness were determined via histomorphological analysis. The ECC intervention resulted in an increased fraction of EBD-positive fibers, a larger CSA, and decreased roundness. The fraction of EBD-positive fibers was 79% lower in the ECC + Str group than in the ECC group. However, there was no difference in the CSA and roundness of the EBD-positive fibers between the two ECC groups. These results suggest that Str administration can reduce the number of myofibers that increase membrane permeability following ECC, but does not ameliorate the extent of fiber swelling in extant EBD-positive fibers. Anat Rec, 301:1096-1102, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Keishi Hayao
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Hiroyuki Tamaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Kouki Nakagawa
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Keigo Tamakoshi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Hideaki Takahashi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Kengo Yotani
- National Institute of Fitness and Sports in Kanoya, Kanoya, Kagoshima, Japan
| | - Futoshi Ogita
- National Institute of Fitness and Sports in Kanoya, Kanoya, Kagoshima, Japan
| | - Noriaki Yamamoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.,Niigata Rehabilitation Hospital, Niigata, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
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141
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Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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142
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Verkhratsky A, Nedergaard M. Physiology of Astroglia. Physiol Rev 2018; 98:239-389. [PMID: 29351512 PMCID: PMC6050349 DOI: 10.1152/physrev.00042.2016] [Citation(s) in RCA: 942] [Impact Index Per Article: 157.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/22/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023] Open
Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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143
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Forecki J, Van Antwerp DJ, Lujan SM, Merzdorf CS. Roles for Xenopus aquaporin-3b (aqp3.L) during gastrulation: Fibrillar fibronectin and tissue boundary establishment in the dorsal margin. Dev Biol 2018; 433:3-16. [PMID: 29113748 DOI: 10.1016/j.ydbio.2017.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 11/02/2017] [Accepted: 11/02/2017] [Indexed: 01/02/2023]
Abstract
Aquaporins and aquaglyceroporins are a large family of membrane channel proteins that allow rapid movement of water and small, uncharged solutes into and out of cells along concentration gradients. Recently, aquaporins have been gaining recognition for more complex biological roles than the regulation of cellular osmotic homeostasis. We have identified a specific expression pattern for Xenopus aqp3b (also called aqp3.L) during gastrulation, where it is localized to the sensorial (deep) layer of the blastocoel roof and dorsal margin. Interference with aqp3b expression resulted in loss of fibrillar fibronectin matrix in Brachet's cleft at the dorsal marginal zone, but not on the free surface of the blastocoel. Detailed observation showed that the absence of fibronectin matrix correlated with compromised border integrities between involuted mesendoderm and noninvoluted ectoderm in the marginal zone. Knockdown of aqp3b also led to delayed closure of the blastopore, suggesting defects in gastrulation movements. Radial intercalation was not affected in aqp3b morphants, while the data presented are consistent with impeded convergent extension movements of the dorsal mesoderm in response to loss of aqp3b. Our emerging model suggests that aqp3b is part of a mechanism that promotes proper interaction between cells and the extracellular matrix, thereby playing a critical role in gastrulation.
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Affiliation(s)
- Jennifer Forecki
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.
| | - Daniel J Van Antwerp
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.
| | - Sean M Lujan
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.
| | - Christa S Merzdorf
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.
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144
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Verkman AS, Smith AJ, Phuan PW, Tradtrantip L, Anderson MO. The aquaporin-4 water channel as a potential drug target in neurological disorders. Expert Opin Ther Targets 2017; 21:1161-1170. [PMID: 29072508 DOI: 10.1080/14728222.2017.1398236] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Aquaporin-4 (AQP4) is a water transporting protein expressed at the plasma membrane of astrocytes throughout the central nervous system (CNS). Analysis of AQP4 knockout mice has suggested its broad involvement in brain water balance, neuroexcitation, glial scarring, neuroinflammation, and even neurodegenerative and neuropsychiatric disorders. Broad clinical utility of AQP4 modulators has been speculated. Area covered: This review covers the biology of AQP4, evidence for its roles in normal CNS function and neurological disorders, and progress in AQP4 drug discovery. Expert opinion: Critical examination of available data reduces the lengthy potential applications list to AQP4 inhibitors for early therapy of ischemic stroke and perhaps for reduction of glial scarring following CNS injury. Major challenges in identification and clinical development of AQP4 inhibitors include the apparent poor druggability of AQPs, the many homologous AQP isoforms with broad tissue distribution and functions, technical issues with water transport assays, predicted undesired CNS and non-CNS actions, and the need for high blood-brain barrier permeation. To date, despite considerable effort, validated small-molecule AQP4 inhibitors have not been advanced. However, a biologic ('aquaporumab') is in development for neuromyelitis optica, an autoimmune inflammatory demyelinating disease where CNS pathology is initiated by binding of anti-AQP4 autoantibodies to astrocyte AQP4.
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Affiliation(s)
- Alan S Verkman
- a Departments of Medicine and Physiology , University of California , San Francisco , CA , USA
| | - Alex J Smith
- a Departments of Medicine and Physiology , University of California , San Francisco , CA , USA
| | - Puay-Wah Phuan
- a Departments of Medicine and Physiology , University of California , San Francisco , CA , USA
| | - Lukmanee Tradtrantip
- a Departments of Medicine and Physiology , University of California , San Francisco , CA , USA
| | - Marc O Anderson
- a Departments of Medicine and Physiology , University of California , San Francisco , CA , USA.,b Department of Chemistry and Biochemistry , San Francisco State University , San Francisco , CA , USA
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145
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Yi M, Wei T, Wang Y, Lu Q, Chen G, Gao X, Geller HM, Chen H, Yu Z. The potassium channel KCa3.1 constitutes a pharmacological target for astrogliosis associated with ischemia stroke. J Neuroinflammation 2017; 14:203. [PMID: 29037241 PMCID: PMC5644250 DOI: 10.1186/s12974-017-0973-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/27/2017] [Indexed: 12/11/2022] Open
Abstract
Background Reactive astrogliosis is one of the significantly pathological features in ischemic stroke accompanied with changes in gene expression, morphology, and proliferation. KCa3.1 was involved in TGF-β-induced astrogliosis in vitro and also contributed to astrogliosis-mediated neuroinflammation in neurodegeneration disease. Methods Wild type mice and KCa3.1−/− mice were subjected to permanent middle cerebral artery occlusion (pMCAO) to evaluate the infarct areas by 2,3,5-triphenyltetrazolium hydrochloride staining and neurological deficit. KCa3.1 channels expression and cell localization in the brain of pMCAO mice model were measured by immunoblotting and immunostaining. Glia activation and neuron loss was measured by immunostaining. DiBAC4 (3) and Fluo-4AM were used to measure membrane potential and cytosolic Ca2+ level in oxygen-glucose deprivation induced reactive astrocytes in vitro. Results Immunohistochemistry on pMCAO mice infarcts showed strong upregulation of KCa3.1 immunoreactivity in reactive astrogliosis. KCa3.1−/− mice exhibited significantly smaller infarct areas on pMCAO and improved neurological deficit. Both activated gliosis and neuronal loss were attenuated in KCa3.1−/− pMCAO mice. In the primary cultured astrocytes, the expressions of KCa3.1 and TRPV4 were increased associated with upregulation of astrogliosis marker GFAP induced by oxygen-glucose deprivation. The activation of KCa3.1 hyperpolarized membrane potential and, by promoting the driving force for calcium, induced calcium entry through TRPV4, a cation channel of the transient receptor potential family. Double-labeled staining showed that KCa3.1 and TRPV4 channels co-localized in astrocytes. Blockade of KCa3.1 or TRPV4 inhibited the phenotype switch of reactive astrogliosis. Conclusions Our data suggested that KCa3.1 inhibition might represent a promising therapeutic strategy for ischemia stroke. Electronic supplementary material The online version of this article (10.1186/s12974-017-0973-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mengni Yi
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Tianjiao Wei
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yanxia Wang
- Experimental Teaching Center of Basic Medicine, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Qin Lu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Gaoxian Chen
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xiaoling Gao
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Herbert M Geller
- Developmental Neurobiology Section, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Hongzhuan Chen
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Zhihua Yu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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146
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Salman MM, Kitchen P, Woodroofe MN, Brown JE, Bill RM, Conner AC, Conner MT. Hypothermia increases aquaporin 4 (AQP4) plasma membrane abundance in human primary cortical astrocytes via a calcium/transient receptor potential vanilloid 4 (TRPV4)- and calmodulin-mediated mechanism. Eur J Neurosci 2017; 46:2542-2547. [PMID: 28925524 PMCID: PMC5765450 DOI: 10.1111/ejn.13723] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 09/14/2017] [Accepted: 09/15/2017] [Indexed: 02/03/2023]
Abstract
Human aquaporin 4 (AQP4) is the primary water channel protein in brain astrocytes. Hypothermia is known to cause astrocyte swelling in culture, but the precise role of AQP4 in this process is unknown. Primary human cortical astrocytes were cultured under hypothermic (32 °C) or normothermic (37 °C) conditions. AQP4 transcript, total protein and surface‐localized protein were quantified using RT‐qPCR, sandwich ELISA with whole cell lysates or cell surface biotinylation, followed by ELISA analysis of the surface‐localized protein, respectively. Four‐hour mild hypothermic treatment increased the surface localization of AQP4 in human astrocytes to 155 ± 4% of normothermic controls, despite no change in total protein expression levels. The hypothermia‐mediated increase in AQP4 surface abundance on human astrocytes was blocked using either calmodulin antagonist (trifluoperazine, TFP); TRPV4 antagonist, HC‐067047 or calcium chelation using EGTA‐AM. The TRPV4 agonist (GSK1016790A) mimicked the effect of hypothermia compared with untreated normothermic astrocytes. Hypothermia led to an increase in surface localization of AQP4 in human astrocytes through a mechanism likely dependent on the TRPV4 calcium channel and calmodulin activation. Understanding the effects of hypothermia on astrocytic AQP4 cell surface expression may help develop new treatments for brain swelling based on an in‐depth mechanistic understanding of AQP4 translocation.
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Affiliation(s)
- Mootaz M Salman
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, UK
| | - Philip Kitchen
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - M Nicola Woodroofe
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, UK
| | - James E Brown
- School of Life & Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Roslyn M Bill
- School of Life & Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Alex C Conner
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Matthew T Conner
- Research Institute of Health Sciences, Wolverhampton School of Sciences, University of Wolverhampton, Wulfruna St, Wolverhampton, WV1 1LY, UK
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147
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AQP4e-Based Orthogonal Arrays Regulate Rapid Cell Volume Changes in Astrocytes. J Neurosci 2017; 37:10748-10756. [PMID: 28978666 DOI: 10.1523/jneurosci.0776-17.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/31/2017] [Accepted: 09/23/2017] [Indexed: 01/28/2023] Open
Abstract
Water channel aquaporin 4 (AQP4) plays a key role in the regulation of water homeostasis in the brain. It is predominantly expressed in astrocytes at the blood-brain and blood-liquor interfaces. Although several AQP4 isoforms have been identified in the mammalian brain, two, AQP4a (M1) and AQP4c (M23), have been confirmed to cluster into plasma membrane supramolecular structures, termed orthogonal arrays of particles (OAPs) and to enhance water transport through the plasma membrane. However, the role of the newly described water-conductive mammalian isoform AQP4e is unknown. Here, the dynamics of AQP4e aggregation into OAPs and its role in the regulation of astrocyte water homeostasis have been studied. Using super-resolution structured illumination, atomic force, and confocal microscopies, the results revealed that, in female rat astrocytes, AQP4e isoform colocalizes with OAPs, affecting its structural dynamics. In hypoosmotic conditions, which elicit cell edema, OAP formation was considerably enhanced by overexpressed AQP4e. Moreover, the kinetics of the cell swelling and of the regulatory volume decrease was faster in astrocytes overexpressing AQP4e compared with untransfected controls. Furthermore, the increase in maximal cell volume elicited by hypoosmotic stimulation was significantly smaller in AQP4e-overexpressing astrocytes. For the first time, this study demonstrates an active role of AQP4e in the regulation of OAP structural dynamics and in water homeostasis.SIGNIFICANCE STATEMENT Water channel aquaporin 4 (AQP4) plays a key role in the regulation of water homeostasis in the brain. To date, only AQP4a and AQP4c isoforms have been confirmed to enhance water transport through plasmalemma and to cluster into orthogonal arrays of particles (OAPs). We here studied the dynamics, aggregation, and role in the regulation of astrocyte water homeostasis of the newly described water-conductive mammalian isoform AQP4e. Our main findings are as follows: brain edema mimicking hypoosmotic conditions stimulates the formation of new OAPs with larger diameters, due to the incorporation of additional cytoplasmic AQP4 channels and the redistribution of AQP4 channels of the existing OAPs; and AQP4e affects the dynamics of cell swelling and regulatory volume decrease in astrocytes exposed to hypoosmotic conditions.
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148
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Friscourt F, Badaut J. Aquaporins through the brain in health and disease: From water to gas movements. J Neurosci Res 2017; 96:177-179. [PMID: 28960397 DOI: 10.1002/jnr.24155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 08/22/2017] [Accepted: 08/22/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Frédéric Friscourt
- CNRS UMR 5287, INCIA, University of Bordeaux, Bordeaux, France.,Institut Européen de Chimie et Biologie, University of Bordeaux, Pessac, France
| | - Jerome Badaut
- CNRS UMR 5287, INCIA, University of Bordeaux, Bordeaux, France.,Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
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149
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Murphy TR, Davila D, Cuvelier N, Young LR, Lauderdale K, Binder DK, Fiacco TA. Hippocampal and Cortical Pyramidal Neurons Swell in Parallel with Astrocytes during Acute Hypoosmolar Stress. Front Cell Neurosci 2017; 11:275. [PMID: 28979186 PMCID: PMC5611379 DOI: 10.3389/fncel.2017.00275] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/28/2017] [Indexed: 01/08/2023] Open
Abstract
Normal nervous system function is critically dependent on the balance of water and ions in the extracellular space (ECS). Pathological reduction in brain interstitial osmolarity results in osmotically-driven flux of water into cells, causing cellular edema which reduces the ECS and increases neuronal excitability and risk of seizures. Astrocytes are widely considered to be particularly susceptible to cellular edema due to selective expression of the water channel aquaporin-4 (AQP4). The apparent resistance of pyramidal neurons to osmotic swelling has been attributed to lack of functional water channels. In this study we report rapid volume changes in CA1 pyramidal cells in hypoosmolar ACSF (hACSF) that are equivalent to volume changes in astrocytes across a variety of conditions. Astrocyte and neuronal swelling was significant within 1 min of exposure to 17 or 40% hACSF, was rapidly reversible upon return to normosmolar ACSF, and repeatable upon re-exposure to hACSF. Neuronal swelling was not an artifact of patch clamp, occurred deep in tissue, was similar at physiological vs. room temperature, and occurred in both juvenile and adult hippocampal slices. Neuronal swelling was neither inhibited by TTX, nor by antagonists of NMDA or AMPA receptors, suggesting that it was not occurring as a result of excitotoxicity. Surprisingly, genetic deletion of AQP4 did not inhibit, but rather augmented, astrocyte swelling in severe hypoosmolar conditions. Taken together, our results indicate that neurons are not osmoresistant as previously reported, and that osmotic swelling is driven by an AQP4-independent mechanism.
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Affiliation(s)
- Thomas R. Murphy
- Division of Biomedical Sciences, School of Medicine, University of California, RiversideRiverside, CA, United States
- Center for Glial-Neuronal Interactions, University of California, RiversideRiverside, CA, United States
| | - David Davila
- Center for Glial-Neuronal Interactions, University of California, RiversideRiverside, CA, United States
- Department of Cell Biology and Neuroscience, University of California, RiversideRiverside, CA, United States
| | - Nicholas Cuvelier
- Center for Glial-Neuronal Interactions, University of California, RiversideRiverside, CA, United States
- Department of Cell Biology and Neuroscience, University of California, RiversideRiverside, CA, United States
| | - Leslie R. Young
- Center for Glial-Neuronal Interactions, University of California, RiversideRiverside, CA, United States
- Department of Cell Biology and Neuroscience, University of California, RiversideRiverside, CA, United States
| | - Kelli Lauderdale
- Division of Biomedical Sciences, School of Medicine, University of California, RiversideRiverside, CA, United States
- Center for Glial-Neuronal Interactions, University of California, RiversideRiverside, CA, United States
| | - Devin K. Binder
- Division of Biomedical Sciences, School of Medicine, University of California, RiversideRiverside, CA, United States
- Center for Glial-Neuronal Interactions, University of California, RiversideRiverside, CA, United States
| | - Todd A. Fiacco
- Center for Glial-Neuronal Interactions, University of California, RiversideRiverside, CA, United States
- Department of Cell Biology and Neuroscience, University of California, RiversideRiverside, CA, United States
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150
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Bedini A, Baiula M, Vincelli G, Formaggio F, Lombardi S, Caprini M, Spampinato S. Nociceptin/orphanin FQ antagonizes lipopolysaccharide-stimulated proliferation, migration and inflammatory signaling in human glioblastoma U87 cells. Biochem Pharmacol 2017; 140:89-104. [PMID: 28583844 DOI: 10.1016/j.bcp.2017.05.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/31/2017] [Indexed: 01/01/2023]
Abstract
Glioblastoma is among the most aggressive brain tumors and has an exceedingly poor prognosis. Recently, the importance of the tumor microenvironment in glioblastoma cell growth and progression has been emphasized. Toll-like receptor 4 (TLR4) recognizes bacterial lipopolysaccharide (LPS) and endogenous ligands originating from dying cells or the extracellular matrix involved in host defense and in inflammation. G-protein coupled receptors (GPCRs) have gained interest in anti-tumor drug discovery due to the role that they directly or indirectly play by transactivating other receptors, causing cell migration and proliferation. A proteomic analysis showed that the nociceptin receptor (NOPr) is among the GPCRs significantly expressed in glioblastoma cells, including U87 cells. We describe a novel role of the peptide nociceptin (N/OFQ), the endogenous ligand of the NOPr that counteracts cell migration, proliferation and increase in IL-1β mRNA elicited by LPS via TLR4 in U87 glioblastoma cells. Signaling pathways through which N/OFQ inhibits LPS-mediated cell migration and elevation of [Ca2+]i require β-arrestin 2 and are sensitive to TNFR-associated factor 6, c-Src and protein kinase C (PKC). LPS-induced cell proliferation and increase in IL-1β mRNA are counteracted by N/OFQ via β-arrestin 2, PKC and extracellular signal-regulated kinase 1/2; furthermore, the contributions of the transcription factors NF-kB and AP-1 were investigated. Independent of LPS, N/OFQ induces a significant increase in cell apoptosis. Contrary to what was observed in other cell models, a prolonged exposure to this endotoxin did not promote any tolerance of the cellular effects above described, including NOPr down-regulation while N/OFQ loses its inhibitory role.
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Affiliation(s)
- Andrea Bedini
- Department of Pharmacy and Biotechnology, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Monica Baiula
- Department of Pharmacy and Biotechnology, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Gabriele Vincelli
- Department of Pharmacy and Biotechnology, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Francesco Formaggio
- Department of Pharmacy and Biotechnology, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Sara Lombardi
- Department of Pharmacy and Biotechnology, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Marco Caprini
- Department of Pharmacy and Biotechnology, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Santi Spampinato
- Department of Pharmacy and Biotechnology, University of Bologna, Irnerio 48, 40126 Bologna, Italy.
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