1
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Tang Y, Zhou Y, Ren J, Wang Y, Li X, Qi M, Yang Y, Zhu C, Wang C, Ma Y, Tang Z, Yu G. TRPV4-β-catenin axis is a novel therapeutic target for dry skin-induced chronic itch. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167491. [PMID: 39218273 DOI: 10.1016/j.bbadis.2024.167491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 08/13/2024] [Accepted: 08/22/2024] [Indexed: 09/04/2024]
Abstract
Dry skin induced chronic pruritus is an increasingly common and debilitating problem, especially in the elderly. Although keratinocytes play important roles in innate and adaptive immunity and keratinocyte proliferation is a key feature of dry skin induced chronic pruritus, the exact contribution of keratinocytes to the pathogenesis of dry skin induced chronic pruritus is poorly understood. In this study, we generated the acetone-ether-water induced dry skin model in mice and found that epidermal hyperplasia induced by this model is partly dependent on the β-catenin signaling pathway. XAV939, an antagonist of β-catenin signaling pathway, inhibited epidermal hyperplasia in dry skin model mice. Importantly, dry skin induced chronic pruritus also dramatically reduced in XAV939 treated mice. Moreover, acetone-ether-water treatment-induced epidermal hyperplasia and chronic itch were decreased in Trpv4-/- mice. In vitro, XAV939 inhibited hypo-osmotic stress induced proliferation of HaCaT cells, and hypo-osmotic stress induced proliferation of in HaCaT cells and primary cultured keratinocytes were also significantly reduced by blocking TRPV4 function. Finally, thymic stromal lymphopoietin release was examined both in vivo and in vitro, which was significantly inhibited by XAV939 treatment and Trpv4 deficiency, and anti-TSLP antibody treatment significantly decreased AEW-induced scratching behavior. Overall, our study revealed a unique ability of TRPV4 expressing keratinocytes in the skin, which critically mediated dry skin induced epidermal hyperplasia and chronic pruritus, thus provided novel insights into the development of therapies for chronic pruritus in the elderly.
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Affiliation(s)
- Ye Tang
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, China; Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Yuan Zhou
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Jiahui Ren
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Yin Wang
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Xue Li
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Mingxin Qi
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Yan Yang
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Chan Zhu
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Changming Wang
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Yuxiang Ma
- School of Life Science, China Pharmaceutical University, Nanjing, Jiangsu 210009, China.
| | - Zongxiang Tang
- Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China.
| | - Guang Yu
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, China; Key Laboratory for Chinese Medicine of Prevention and Treatment in Neurological Diseases, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China.
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2
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Michelucci A, Catacuzzeno L. Piezo1, the new actor in cell volume regulation. Pflugers Arch 2024; 476:1023-1039. [PMID: 38581527 PMCID: PMC11166825 DOI: 10.1007/s00424-024-02951-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/29/2024] [Accepted: 03/20/2024] [Indexed: 04/08/2024]
Abstract
All animal cells control their volume through a complex set of mechanisms, both to counteract osmotic perturbations of the environment and to enable numerous vital biological processes, such as proliferation, apoptosis, and migration. The ability of cells to adjust their volume depends on the activity of ion channels and transporters which, by moving K+, Na+, and Cl- ions across the plasma membrane, generate the osmotic gradient that drives water in and out of the cell. In 2010, Patapoutian's group identified a small family of evolutionarily conserved, Ca2+-permeable mechanosensitive channels, Piezo1 and Piezo2, as essential components of the mechanically activated current that mediates mechanotransduction in vertebrates. Piezo1 is expressed in several tissues and its opening is promoted by a wide range of mechanical stimuli, including membrane stretch/deformation and osmotic stress. Piezo1-mediated Ca2+ influx is used by the cell to convert mechanical forces into cytosolic Ca2+ signals that control diverse cellular functions such as migration and cell death, both dependent on changes in cell volume and shape. The crucial role of Piezo1 in the regulation of cell volume was first demonstrated in erythrocytes, which need to reduce their volume to pass through narrow capillaries. In HEK293 cells, increased expression of Piezo1 was found to enhance the regulatory volume decrease (RVD), the process whereby the cell re-establishes its original volume after osmotic shock-induced swelling, and it does so through Ca2+-dependent modulation of the volume-regulated anion channels. More recently we reported that Piezo1 controls the RVD in glioblastoma cells via the modulation of Ca2+-activated K+ channels. To date, however, the mechanisms through which this mechanosensitive channel controls cell volume and maintains its homeostasis have been poorly investigated and are still far from being understood. The present review aims to provide a broad overview of the literature discussing the recent advances on this topic.
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Affiliation(s)
- A Michelucci
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123, Perugia, Italy.
| | - L Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123, Perugia, Italy.
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3
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Matsumoto T, Taguchi K, Kobayashi T. Role of TRPV4 on vascular tone regulation in pathophysiological states. Eur J Pharmacol 2023; 959:176104. [PMID: 37802278 DOI: 10.1016/j.ejphar.2023.176104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/20/2023] [Accepted: 10/04/2023] [Indexed: 10/08/2023]
Abstract
Vascular tone regulation is a key event in controlling blood flow in the body. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) help regulate the vascular tone. Abnormal vascular responsiveness to various stimuli, including constrictors and dilators, has been observed in pathophysiological states although EC and VSMC coordinate to maintain the exquisite balance between contraction and relaxation in vasculatures. Thus, investigating the mechanisms underlying vascular tone abnormality is very important in maintaining vascular health and treating vasculopathy. Increased intracellular free Ca2+ concentration ([Ca2+]i) is one of the major triggers initiating each EC and VSMC response. Transient receptor potential vanilloid family member 4 (TRPV4) is a Ca2+-permeable non-selective ion channel, which is activated by several stimuli, and is presented in both ECs and VSMCs. Therefore, TRPV4 plays an important role in vascular responses. Emerging evidence indicates the role of TRPV4 on the functions of ECs and VSMCs in various pathophysiological states, including hypertension, diabetes, and obesity. This review focused on the link between TRPV4 and the functions of ECs/VSMCs, particularly its role in vascular tone and responsiveness to vasoactive substances.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Pharmaceutical Education and Research, Pharmaceutical Education and Research Center, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan.
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan
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4
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Michelucci A, Sforna L, Di Battista A, Franciolini F, Catacuzzeno L. Ca 2+ -activated K + channels regulate cell volume in human glioblastoma cells. J Cell Physiol 2023; 238:2120-2134. [PMID: 37431808 DOI: 10.1002/jcp.31072] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/10/2023] [Accepted: 06/20/2023] [Indexed: 07/12/2023]
Abstract
Glioblastoma (GBM), the most lethal form of brain tumors, bases its malignancy on the strong ability of its cells to migrate and invade the narrow spaces of healthy brain parenchyma. Cell migration and invasion are both critically dependent on changes in cell volume and shape driven by the transmembrane transport of osmotically important ions such as K+ and Cl- . However, while the Cl- channels participating in cell volume regulation have been clearly identified, the precise nature of the K+ channels involved is still uncertain. Using a combination of electrophysiological and imaging approaches in GBM U87-MG cells, we found that hypotonic-induced cell swelling triggered the opening of Ca2+ -activated K+ (KCa ) channels of large and intermediate conductance (BKCa and IKCa , respectively), both highly expressed in GBM cells. The influx of Ca2+ mediated by the hypotonic-induced activation of mechanosensitive channels was found to be a key step for opening both the BKCa and the IKCa channels. Finally, the activation of both KCa channels mediated by mechanosensitive channels was found to be essential for the development of the regulatory volume decrease following hypotonic shock. Taken together, these data indicate that KCa channels are the main K+ channels responsible for the volume regulation in U87-MG cells.
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Affiliation(s)
- Antonio Michelucci
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, Perugia, Italy
| | - Luigi Sforna
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, Perugia, Italy
| | - Angela Di Battista
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, Perugia, Italy
| | - Fabio Franciolini
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, Perugia, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, Perugia, Italy
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5
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Zholos AV, Dryn DO, Melnyk MI. General anaesthesia-related complications of gut motility with a focus on cholinergic mechanisms, TRP channels and visceral pain. Front Physiol 2023; 14:1174655. [PMID: 37275228 PMCID: PMC10232893 DOI: 10.3389/fphys.2023.1174655] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/09/2023] [Indexed: 06/07/2023] Open
Abstract
General anesthesia produces multiple side effects. Notably, it temporarily impairs gastrointestinal motility following surgery and causes the so-called postoperative ileus (POI), a multifactorial and complex condition that develops secondary to neuromuscular failure and mainly affects the small intestine. There are currently limited medication options for POI, reflecting a lack of comprehensive understanding of the mechanisms involved in this complex condition. Notably, although acetylcholine is one of the major neurotransmitters initiating excitation-contraction coupling in the gut, cholinergic stimulation by prokinetic drugs is not very efficient in case of POI. Acetylcholine when released from excitatory motoneurones of the enteric nervous system binds to and activates M2 and M3 types of muscarinic receptors in smooth muscle myocytes. Downstream of these G protein-coupled receptors, muscarinic cation TRPC4 channels act as the major focal point of receptor-mediated signal integration, causing membrane depolarisation accompanied by action potential discharge and calcium influx via L-type Ca2+ channels for myocyte contraction. We have recently found that both inhalation (isoflurane) and intravenous (ketamine) anesthetics significantly inhibit this muscarinic cation current (termed mI CAT) in ileal myocytes, even when G proteins are activated directly by intracellular GTPγS, i.e., bypassing muscarinic receptors. Here we aim to summarize Transient Receptor Potential channels and calcium signalling-related aspects of the cholinergic mechanisms in the gut and visceral pain, discuss exactly how these may be negatively impacted by general anaesthetics, while proposing the receptor-operated TRPC4 channel as a novel molecular target for the treatment of POI.
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Affiliation(s)
- Alexander V. Zholos
- ESC “Institute of Biology and Medicine”, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Dariia O. Dryn
- O.O. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Mariia I. Melnyk
- ESC “Institute of Biology and Medicine”, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
- O.O. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
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6
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Miyano T, Suzuki A, Sakamoto N. Calcium influx through TRPV4 channels involve in hyperosmotic stress-induced epithelial-mesenchymal transition in tubular epithelial cells. Biochem Biophys Res Commun 2022; 617:48-54. [PMID: 35689842 DOI: 10.1016/j.bbrc.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/01/2022] [Indexed: 11/24/2022]
Abstract
The epithelial-mesenchymal transition (EMT) is a biological process that occurs in the pathogenesis of kidney diseases in which injured tubular epithelial cells transform into myofibroblasts. We previously showed that mannitol-mediated hyperosmotic stress induces EMT of tubular epithelial cells. Although Ca2+ signaling is essential for the induction of EMT in tubular epithelial cells, the role of specific calcium channels is unknown. In this study, we assessed the transient receptor potential vanilloid 4 (TRPV4)-mediated Ca2+ influx in the hyperosmolarity-induced EMT. The Fluo-4 assay was used to examine the effect of hyperosmotic stress on the intracellular Ca2+ level of normal rat kidney (NRK)-52E cells. Expression of a mesenchymal marker α-smooth muscle actin (α-SMA) and an epithelial marker E-cadherin was also observed by fluorescence microscopy. The hyperosmotic stress caused a transient increase in intracellular Ca2+ concentration as well as a decrease in E-cadherin and an increase in α-SMA expressions in tubular epithelial cells, indicating the induction of EMT. A TRPV4 channel antagonist inhibited hyperosmotic stress-induced Ca2+ influx and the EMT, whereas, a TRPV4 channel agonist increased Ca2+ influx and EMT induction in tubular epithelial cells without the hyperosmotic stress. These findings suggest that Ca2+ influx through TRPV4 channels contributes to the hyperosmotic stress-induced EMT of tubular epithelial cells.
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Affiliation(s)
- Takashi Miyano
- Department of Mechanical Systems Engineering, Graduate School of Systems Design, Tokyo Metropolitan University, Tokyo, Japan.
| | - Atsushi Suzuki
- Department of Mechanical Systems Engineering, Graduate School of Systems Design, Tokyo Metropolitan University, Tokyo, Japan
| | - Naoya Sakamoto
- Department of Mechanical Systems Engineering, Graduate School of Systems Design, Tokyo Metropolitan University, Tokyo, Japan.
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Bagnell AM, Sumner CJ, McCray BA. TRPV4: A trigger of pathological RhoA activation in neurological disease. Bioessays 2022; 44:e2100288. [PMID: 35297520 PMCID: PMC9295809 DOI: 10.1002/bies.202100288] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/03/2022] [Accepted: 03/07/2022] [Indexed: 12/14/2022]
Abstract
Transient receptor potential vanilloid 4 (TRPV4), a member of the TRP superfamily, is a broadly expressed, cell surface-localized cation channel that is activated by a variety of environmental stimuli. Importantly, TRPV4 has been increasingly implicated in the regulation of cellular morphology. Here we propose that TRPV4 and the cytoskeletal remodeling small GTPase RhoA together constitute an environmentally sensitive signaling complex that contributes to pathological cell cytoskeletal alterations during neurological injury and disease. Supporting this hypothesis is our recent work demonstrating direct physical and bidirectional functional interactions of TRPV4 with RhoA, which can lead to activation of RhoA and reorganization of the actin cytoskeleton. Furthermore, a confluence of evidence implicates TRPV4 and/or RhoA in pathological responses triggered by a range of acute neurological insults ranging from stroke to traumatic injury. While initiated by a variety of insults, TRPV4-RhoA signaling may represent a common pathway that disrupts axonal regeneration and blood-brain barrier integrity. These insights also suggest that TRPV4 inhibition may represent a safe, feasible, and precise therapeutic strategy for limiting pathological TRPV4-RhoA activation in a range of neurological diseases.
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Affiliation(s)
- Anna M. Bagnell
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Charlotte J. Sumner
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Brett A. McCray
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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8
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Desplat A, Penalba V, Gros E, Parpaite T, Coste B, Delmas P. Piezo1-Pannexin1 complex couples force detection to ATP secretion in cholangiocytes. J Gen Physiol 2021; 153:212722. [PMID: 34694360 PMCID: PMC8548913 DOI: 10.1085/jgp.202112871] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 08/17/2021] [Indexed: 01/07/2023] Open
Abstract
Cholangiocytes actively contribute to the final composition of secreted bile. These cells are exposed to abnormal mechanical stimuli during obstructive cholestasis, which has a deep impact on their function. However, the effects of mechanical insults on cholangiocyte function are not understood. Combining gene silencing and pharmacological assays with live calcium imaging, we probed molecular candidates essential for coupling mechanical force to ATP secretion in mouse cholangiocytes. We show that Piezo1 and Pannexin1 are necessary for eliciting the downstream effects of mechanical stress. By mediating a rise in intracellular Ca2+, Piezo1 acts as a mechanosensor responsible for translating cell swelling into activation of Panx1, which triggers ATP release and subsequent signal amplification through P2X4R. Co-immunoprecipitation and pull-down assays indicated physical interaction between Piezo1 and Panx1, which leads to stable plasma membrane complexes. Piezo1–Panx1–P2X4R ATP release pathway could be reconstituted in HEK Piezo1 KO cells. Thus, our data suggest that Piezo1 and Panx1 can form a functional signaling complex that controls force-induced ATP secretion in cholangiocytes. These findings may foster the development of novel therapeutic strategies for biliary diseases.
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Affiliation(s)
- Angélique Desplat
- Aix-Marseille-Université, Centre National de la Recherche Scientifique, Laboratoire de Neurosciences Cognitives, UMR 7291, CS80011, Marseille, France
| | - Virginie Penalba
- Aix-Marseille-Université, Centre National de la Recherche Scientifique, Laboratoire de Neurosciences Cognitives, UMR 7291, CS80011, Marseille, France
| | - Emeline Gros
- Aix-Marseille-Université, Centre National de la Recherche Scientifique, Laboratoire de Neurosciences Cognitives, UMR 7291, CS80011, Marseille, France
| | - Thibaud Parpaite
- Aix-Marseille-Université, Centre National de la Recherche Scientifique, Laboratoire de Neurosciences Cognitives, UMR 7291, CS80011, Marseille, France
| | - Bertrand Coste
- Aix-Marseille-Université, Centre National de la Recherche Scientifique, Laboratoire de Neurosciences Cognitives, UMR 7291, CS80011, Marseille, France
| | - Patrick Delmas
- Aix-Marseille-Université, Centre National de la Recherche Scientifique, Laboratoire de Neurosciences Cognitives, UMR 7291, CS80011, Marseille, France
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9
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Shibata M, Tang C. Implications of Transient Receptor Potential Cation Channels in Migraine Pathophysiology. Neurosci Bull 2021; 37:103-116. [PMID: 32870468 PMCID: PMC7811976 DOI: 10.1007/s12264-020-00569-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/11/2020] [Indexed: 12/19/2022] Open
Abstract
Migraine is a common and debilitating headache disorder. Although its pathogenesis remains elusive, abnormal trigeminal and central nervous system activity is likely to play an important role. Transient receptor potential (TRP) channels, which transduce noxious stimuli into pain signals, are expressed in trigeminal ganglion neurons and brain regions closely associated with the pathophysiology of migraine. In the trigeminal ganglion, TRP channels co-localize with calcitonin gene-related peptide, a neuropeptide crucially implicated in migraine pathophysiology. Many preclinical and clinical data support the roles of TRP channels in migraine. In particular, activation of TRP cation channel V1 has been shown to regulate calcitonin gene-related peptide release from trigeminal nerves. Intriguingly, several effective anti-migraine therapies, including botulinum neurotoxin type A, affect the functions of TRP cation channels. Here, we discuss currently available data regarding the roles of major TRP cation channels in the pathophysiology of migraine and the therapeutic applicability thereof.
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Affiliation(s)
- Mamoru Shibata
- Department of Neurology, Keio University School of Medicine, Tokyo, 160-8582, Japan.
- Department of Neurology, Tokyo Dental College Ichikawa General Hospital, Chiba, 272-8513, Japan.
| | - Chunhua Tang
- Department of Neurology, Keio University School of Medicine, Tokyo, 160-8582, Japan
- Department of Neurology and Center for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
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10
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Sadowska A, Altinay B, Hitzl W, Ferguson SJ, Wuertz-Kozak K. Hypo-Osmotic Loading Induces Expression of IL-6 in Nucleus Pulposus Cells of the Intervertebral Disc Independent of TRPV4 and TRPM7. Front Pharmacol 2020; 11:952. [PMID: 32714187 PMCID: PMC7341822 DOI: 10.3389/fphar.2020.00952] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/11/2020] [Indexed: 12/19/2022] Open
Abstract
Painful intervertebral disc (IVD) degeneration is an age-related process characterized by reduced tissue osmolarity, increased catabolism of the extracellular matrix, and elevated levels of pro-inflammatory molecules. With the aging population and constantly rising treatment costs, it is of utmost importance to identify potential therapeutic targets and new pharmacological treatment strategies for low back pain. Transient receptor potential (TRP) channels are a family of Ca2+ permeable cell membrane receptors, which can be activated by multitude of stimuli and have recently emerged as contributors to joint disease, but were not investigated closer in the IVD. Based on the gene array screening, TRPC1, TRPM7, and TRPV4 were overall the most highly expressed TRP channels in bovine IVD cells. We demonstrated that TRPV4 gene expression was down-regulated in hypo-osmotic condition, whereas its Ca2+ flux increased. No significant differences in Ca2+ flux and gene expression were observed for TRPM7 between hypo- and iso-osmotic groups. Upon hypo-osmotic stimulation, we overall identified via RNA sequencing over 3,000 up- or down-regulated targets, from which we selected aggrecan, ADAMTS9, and IL-6 and investigated whether their altered gene expression is mediated through either the TRPV4 or TRPM7 channel, using specific activators and inhibitors (GSK1016790A/GSK2193874 for TRPV4 and Naltriben/NS8593 for TRPM7). GSK1016790A induced the expression of IL-6 under iso-osmotic condition, alike to hypo-osmotic stimulation alone, indicating that this effect might be TRPV4-mediated. However, using the TRPV4 blocker GSK2193874 failed to prevent the increase of IL-6 under hypo-osmotic condition. A treatment with TRPM7-activator did not cause significant changes in the gene expression of tested targets. In conclusion, while TRPV4 and TRPM7 are likely involved in osmosensing in the IVD, neither of them mediates hypo-osmotically-induced gene expression changes of aggrecan, ADAMTS9, and IL-6.
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Affiliation(s)
| | - Birsen Altinay
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Wolfgang Hitzl
- Research Office (Biostatistics), Paracelsus Medical University, Salzburg, Austria.,Department of Ophthalmology and Optometry, Paracelsus Medical University Salzburg, Salzburg, Austria.,Research Program Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University, Salzburg, Austria
| | | | - Karin Wuertz-Kozak
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.,Tissue Regeneration & Mechanobiology Lab, Department of Biomedical Engineering, Rochester Institute of Technology (RIT), Rochester, NY, United States.,Spine Center, Schön Clinic Munich Harlaching, Academic Teaching Hospital and Spine Research Institute of the Salzburg Paracelsus Medical University, Munich, Germany
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11
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Li J, Wen AM, Potla R, Benshirim E, Seebarran A, Benz MA, Henry OYF, Matthews BD, Prantil-Baun R, Gilpin SE, Levy O, Ingber DE. AAV-mediated gene therapy targeting TRPV4 mechanotransduction for inhibition of pulmonary vascular leakage. APL Bioeng 2019; 3:046103. [PMID: 31803860 PMCID: PMC6887658 DOI: 10.1063/1.5122967] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/28/2019] [Indexed: 12/11/2022] Open
Abstract
Enhanced vascular permeability in the lungs can lead to pulmonary edema, impaired gas exchange, and ultimately respiratory failure. While oxygen delivery, mechanical ventilation, and pressure-reducing medications help alleviate these symptoms, they do not treat the underlying disease. Mechanical activation of transient receptor potential vanilloid 4 (TRPV4) ion channels contributes to the development of pulmonary vascular disease, and overexpression of the high homology (HH) domain of the TRPV4-associated transmembrane protein CD98 has been shown to inhibit this pathway. Here, we describe the development of an adeno-associated virus (AAV) vector encoding the CD98 HH domain in which the AAV serotypes and promoters have been optimized for efficient and specific delivery to pulmonary cells. AAV-mediated gene delivery of the CD98 HH domain inhibited TRPV4 mechanotransduction in a specific manner and protected against pulmonary vascular leakage in a human lung Alveolus-on-a-Chip model. As AAV has been used clinically to deliver other gene therapies, these data raise the possibility of using this type of targeted approach to develop mechanotherapeutics that target the TRPV4 pathway for treatment of pulmonary edema in the future.
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Affiliation(s)
- Juan Li
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, USA
| | - Amy M Wen
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, USA
| | | | | | | | - Maximilian A Benz
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, USA
| | - Olivier Y F Henry
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, USA
| | | | - Rachelle Prantil-Baun
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, USA
| | - Sarah E Gilpin
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, USA
| | - Oren Levy
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, USA
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12
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Toft-Bertelsen TL, Križaj D, MacAulay N. When size matters: transient receptor potential vanilloid 4 channel as a volume-sensor rather than an osmo-sensor. J Physiol 2017; 595:3287-3302. [PMID: 28295351 DOI: 10.1113/jp274135] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS Mammalian cells are frequently exposed to stressors causing volume changes. The transient receptor potential vanilloid 4 (TRPV4) channel translates osmotic stress into ion flux. The molecular mechanism coupling osmolarity to TRPV4 activation remains elusive. TRPV4 responds to isosmolar cell swelling and osmolarity translated via different aquaporins. TRPV4 functions as a volume-sensing ion channel irrespective of the origin of the cell swelling. ABSTRACT Transient receptor potential channel 4 of the vanilloid subfamily (TRPV4) is activated by a diverse range of molecular cues, such as heat, lipid metabolites and synthetic agonists, in addition to hyposmotic challenges. As a non-selective cation channel permeable to Ca2+ , it transduces physical stress in the form of osmotic cell swelling into intracellular Ca2+ -dependent signalling events. Its contribution to cell volume regulation might include interactions with aquaporin (AQP) water channel isoforms, although the proposed requirement for a TRPV4-AQP4 macromolecular complex remains to be resolved. To characterize the elusive mechanics of TRPV4 volume-sensing, we expressed the channel in Xenopus laevis oocytes together with AQP4. Co-expression with AQP4 facilitated the cell swelling induced by osmotic challenges and thereby activated TRPV4-mediated transmembrane currents. Similar TRPV4 activation was induced by co-expression of a cognate channel, AQP1. The level of osmotically-induced TRPV4 activation, although proportional to the degree of cell swelling, was dependent on the rate of volume changes. Importantly, isosmotic cell swelling obtained by parallel activation of the co-expressed water-translocating Na+ /K+ /2Cl- cotransporter promoted TRPV4 activation despite the absence of the substantial osmotic gradients frequently employed for activation. Upon simultaneous application of an osmotic gradient and the selective TRPV4 agonist GSK1016790A, enhanced TRPV4 activation was observed only with subsaturating stimuli, indicating that the agonist promotes channel opening similar to that of volume-dependent activation. We propose that, contrary to the established paradigm, TRPV4 is activated by increased cell volume irrespective of the molecular mechanism underlying cell swelling. Thus, the channel functions as a volume-sensor, rather than as an osmo-sensor.
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Affiliation(s)
- Trine L Toft-Bertelsen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Nanna MacAulay
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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Reinach PS, Mergler S, Okada Y, Saika S. Ocular transient receptor potential channel function in health and disease. BMC Ophthalmol 2015; 15 Suppl 1:153. [PMID: 26818117 PMCID: PMC4895786 DOI: 10.1186/s12886-015-0135-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Transient receptor potential (TRP) channels sense and transduce environmental stimuli into Ca(2+) transients that in turn induce responses essential for cell function and adaptation. These non-selective channels with variable Ca(2+) selectivity are grouped into seven different subfamilies containing 28 subtypes based on differences in amino acid sequence homology. Many of these subtypes are expressed in the eye on both neuronal and non-neuronal cells where they affect a host of stress-induced regulatory responses essential for normal vision maintenance. This article reviews our current knowledge about the expression, function and regulation of TRPs in different eye tissues. We also describe how under certain conditions TRP activation can induce responses that are maladaptive to ocular function. Furthermore, the possibility of an association between TRP mutations and disease is considered. These findings contribute to evidence suggesting that drug targeting TRP channels may be of therapeutic benefit in a clinical setting. We point out issues that must be more extensively addressed before it will be possible to decide with certainty that this is a realistic endeavor. Another possible upshot of future studies is that disease process progression can be better evaluated by profiling changes in tissue specific functional TRP subtype activity as well as their gene and protein expression.
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Affiliation(s)
- Peter S Reinach
- Department of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xuejuan Road, Wenzhou, Zhejiang, 325027, P. R. China.
| | - Stefan Mergler
- Department of Ophthalmology, Charité-University Medicine Berlin, Campus Virchow-Clinic, Augustenburger Platz 1, 13353, Berlin, Germany.
| | - Yuka Okada
- Department of Ophthalmology, Wakayama Medical University School of Medicine, Wakayama, Japan.
| | - Shizuya Saika
- Department of Ophthalmology, Wakayama Medical University School of Medicine, Wakayama, Japan.
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Shahidullah M, Mandal A, Delamere NA. Damage to lens fiber cells causes TRPV4-dependent Src family kinase activation in the epithelium. Exp Eye Res 2015; 140:85-93. [PMID: 26318609 DOI: 10.1016/j.exer.2015.08.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/08/2015] [Accepted: 08/17/2015] [Indexed: 11/25/2022]
Abstract
The bulk of the lens consists of tightly packed fiber cells. Because mature lens fibers lack mitochondria and other organelles, lens homeostasis relies on a monolayer of epithelial cells at the anterior surface. The detection of various signaling pathways in lens epithelial cells suggests they respond to stimuli that influence lens function. Focusing on Src Family Kinases (SFKs) and Transient Receptor Potential Vanilloid 4 (TRPV4), we tested whether the epithelium can sense and respond to an event that occurs in fiber mass. The pig lens was subjected to localized freeze-thaw (FT) damage to fibers at posterior pole then the lens was incubated for 1-10 min in Krebs solution at 37 °C. Transient SFK activation in the epithelium was detectable at 1 min. Using a western blot approach, the ion channel TRPV4 was detected in the epithelium but was sparse or absent in fiber cells. Even though TRPV4 expression appears low at the actual site of FT damage to the fibers, SFK activation in the epithelium was suppressed in lenses subjected to FT damage then incubated with the TRPV4 antagonist HC067047 (10 μM). Na,K-ATPase activity was examined because previous studies report changes of Na,K-ATPase activity associated with SFK activation. Na,K-ATPase activity doubled in the epithelium removed from FT-damaged lenses and the response was prevented by HC067047 or the SFK inhibitor PP2 (10 μM). Similar changes were observed in response to fiber damage caused by injection of 5 μl hyperosmotic NaCl or mannitol solution beneath the surface of the posterior pole. The findings point to a TRPV4-dependent mechanism that enables the epithelial cells to detect remote damage in the fiber mass and respond within minutes by activating SFK and increasing Na,K-ATPase activity. Because TRPV4 channels are mechanosensitive, we speculate they may be stimulated by swelling of the lens structure caused by damage to the fibers. Increased Na,K-ATPase activity gives the lens greater capacity to control ion concentrations in the fiber mass and the Na,K-ATPase response may reflect the critical contribution of the epithelium to lens ion homeostasis.
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Affiliation(s)
- M Shahidullah
- Dept. of Physiology, University of Arizona, 1501 N Campbell Avenue, Tucson, AZ, 85724, USA.
| | - A Mandal
- Dept. of Physiology, University of Arizona, 1501 N Campbell Avenue, Tucson, AZ, 85724, USA
| | - N A Delamere
- Dept. of Physiology, University of Arizona, 1501 N Campbell Avenue, Tucson, AZ, 85724, USA
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Vizin RCL, Scarpellini CDS, Ishikawa DT, Correa GM, de Souza CO, Gargaglioni LH, Carrettiero DC, Bícego KC, Almeida MC. TRPV4 activates autonomic and behavioural warmth-defence responses in Wistar rats. Acta Physiol (Oxf) 2015; 214:275-89. [PMID: 25739906 DOI: 10.1111/apha.12477] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 02/10/2015] [Accepted: 02/26/2015] [Indexed: 11/28/2022]
Abstract
AIM In this study, we aimed at investigating the involvement of the warmth-sensitive channel - TRPV4 (in vitro sensitive to temperatures in the range of approx. 24-34 °C) - on the thermoregulatory mechanisms in rats. METHODS We treated rats with a chemical selective agonist (RN-1747) and two antagonists (RN-1734 and HC-067047) of the TRPV4 channel and measured core body temperature, metabolism, heat loss index and preferred ambient temperature. RESULTS Our data revealed that chemical activation of TRPV4 channels by topical application of RN-1747 on the skin leads to hypothermia and this effect was blocked by the pre-treatment with the selective antagonist of this channel. Intracerebroventricular treatment with RN-1747 did not cause hypothermia, indicating that the observed response was indeed due to activation of TRPV4 channels in the periphery. Intravenous blockade of this channel with HC-067047 caused an increase in core body temperature at ambient temperature of 26 and 30 °C, but not at 22 and 32 °C. At 26 °C, HC-067047-induced hyperthermia was accompanied by increase in oxygen consumption (an index of thermogenesis), while chemical stimulation of TRPV4 increased tail heat loss, indicating that these two autonomic thermoeffectors in the rat are modulated through TRPV4 channels. Furthermore, rats chemically stimulated with TRPV4 agonist choose colder ambient temperatures and cold-seeking behaviour after thermal stimulation (28-31 °C) was inhibited by TRPV4 antagonist. CONCLUSION Our results suggest, for the first time, that TRPV4 channel is involved in the recruitment of behavioural and autonomic warmth-defence responses to regulate core body temperature.
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Affiliation(s)
- R. C. L. Vizin
- Graduate Program on Neuroscience and Cognition; Universidade Federal do ABC (UFABC); São Bernardo do Campo SP Brazil
| | - C. da S. Scarpellini
- Department of Animal Morphology and Physiology; College of Agricultural and Veterinary Sciences; São Paulo State University; Jaboticabal SP Brazil
- Joint UFSCar-UNESP Graduate Program of Physiological Sciences; Sao Carlos SP Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT - Fisiologia Comparada); Jaboticabal SP Brazil
| | - D. T. Ishikawa
- Graduate Program on Neuroscience and Cognition; Universidade Federal do ABC (UFABC); São Bernardo do Campo SP Brazil
| | - G. M. Correa
- Department of Animal Morphology and Physiology; College of Agricultural and Veterinary Sciences; São Paulo State University; Jaboticabal SP Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT - Fisiologia Comparada); Jaboticabal SP Brazil
| | - C. O. de Souza
- Graduate Program on Neuroscience and Cognition; Universidade Federal do ABC (UFABC); São Bernardo do Campo SP Brazil
| | - L. H. Gargaglioni
- Department of Animal Morphology and Physiology; College of Agricultural and Veterinary Sciences; São Paulo State University; Jaboticabal SP Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT - Fisiologia Comparada); Jaboticabal SP Brazil
| | - D. C. Carrettiero
- Graduate Program on Neuroscience and Cognition; Universidade Federal do ABC (UFABC); São Bernardo do Campo SP Brazil
- Natural and Humanities Science Center; Universidade Federal do ABC (UFABC); São Bernardo do Campo SP Brazil
| | - K. C. Bícego
- Department of Animal Morphology and Physiology; College of Agricultural and Veterinary Sciences; São Paulo State University; Jaboticabal SP Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT - Fisiologia Comparada); Jaboticabal SP Brazil
| | - M. C. Almeida
- Graduate Program on Neuroscience and Cognition; Universidade Federal do ABC (UFABC); São Bernardo do Campo SP Brazil
- Natural and Humanities Science Center; Universidade Federal do ABC (UFABC); São Bernardo do Campo SP Brazil
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Sostegni S, Diakov A, McIntyre P, Bunnett N, Korbmacher C, Haerteis S. Sensitisation of TRPV4 by PAR2 is independent of intracellular calcium signalling and can be mediated by the biased agonist neutrophil elastase. Pflugers Arch 2015; 467:687-701. [PMID: 24906497 PMCID: PMC11450633 DOI: 10.1007/s00424-014-1539-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 05/14/2014] [Accepted: 05/15/2014] [Indexed: 12/21/2022]
Abstract
Proteolytic activation of protease-activated receptor 2 (PAR2) may represent a major mechanism of regulating the transient receptor potential vanilloid 4 (TRPV4) non-selective cation channel in pathophysiological conditions associated with protease activation (e.g. during inflammation). To provide electrophysiological evidence for PAR2-mediated TRPV4 regulation, we characterised the properties of human TRPV4 heterologously expressed in Xenopus laevis oocytes in the presence and absence of co-expressed human PAR2. In outside-out patches from TRPV4 expressing oocytes, we detected single-channel activity typical for TRPV4 with a single-channel conductance of about 100 pS for outward and 55 pS for inward currents. The synthetic TRPV4 activator GSK1016790A stimulated TRPV4 mainly by converting previously silent channels into active channels with an open probability of nearly one. In oocytes co-expressing TRPV4 and PAR2, PAR2 activation by trypsin or by specific PAR2 agonist SLIGRL-NH2 potentiated the GSK1016790A-stimulated TRPV4 whole-cell currents several fold, indicative of channel sensitisation. Pre-incubation of oocytes with the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA)-AM did not reduce the stimulatory effect of PAR2 activation on TRPV4, which indicates that the effect is independent of intracellular calcium signalling. Neutrophil elastase, a biased agonist of PAR2 that does not induce intracellular calcium signalling, also caused a PAR2-dependent sensitisation of TRPV4. The Rho-kinase inhibitor Y27362 abolished elastase-stimulated sensitisation of TRPV4, which indicates that Rho-kinase signalling plays a critical role in PAR2-mediated TRPV4 sensitisation by the biased agonist neutrophil elastase. During acute inflammation, neutrophil elastase may sensitise TRPV4 by a mechanism involving biased agonism of PAR2 and activation of Rho-kinase.
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Affiliation(s)
- Silvia Sostegni
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstr. 6, 91054, Erlangen, Germany
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Rowe I, Anishkin A, Kamaraju K, Yoshimura K, Sukharev S. The cytoplasmic cage domain of the mechanosensitive channel MscS is a sensor of macromolecular crowding. ACTA ACUST UNITED AC 2014; 143:543-57. [PMID: 24778428 PMCID: PMC4003192 DOI: 10.1085/jgp.201311114] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The cytoplasmic “cage” domain of the bacterial MscS channel senses macromolecular crowding to promote channel inactivation and prevent excessive loss of small osmolytes. Cells actively regulate the macromolecular excluded volume of the cytoplasm to maintain the reciprocal fraction of free aqueous solution that is optimal for intracellular processes. However, the mechanisms whereby cells sense this critical parameter remain unclear. The mechanosensitive channel of small conductance (MscS channel), which is the major regulator of turgor in bacteria, mediates efflux of small osmolytes in response to increased membrane tension. At moderate sustained tensions produced by a decrease in external osmolarity, MscS undergoes slow adaptive inactivation; however, it inactivates abruptly in the presence of cytoplasmic crowding agents. To understand the mechanism underlying this rapid inactivation, we combined extrapolated and equilibrium molecular dynamics simulations with electrophysiological analyses of MscS mutants to explore possible transitions of MscS and generated models of the resting and inactivated states. Our models suggest that the coupling of the gate formed by TM3 helices to the peripheral TM1–TM2 pairs depends on the axial position of the core TM3 barrel relative to the TM1–TM2 shaft and the state of the associated hollow cytoplasmic domain (“cage”). They also indicate that the tension-driven inactivation transition separates the gate from the peripheral helices and promotes kinks in TM3s at G113 and that this conformation is stabilized by association of the TM3b segment with the β domain of the cage. We found that mutations destabilizing the TM3b–β interactions preclude inactivation and make the channel insensitive to crowding agents and voltage; mutations that strengthen this association result in a stable closed state and silent inactivation. Steered simulations showed that pressure exerted on the cage bottom in the inactivated state reduces the volume of the cage in the cytoplasm and at the same time increases the footprint of the transmembrane domain in the membrane, implying coupled sensitivity to both membrane tension and crowding pressure. The cage, therefore, provides feedback on the increasing crowding that disengages the gate and prevents excessive draining and condensation of the cytoplasm. We discuss the structural mechanics of cells surrounded by an elastic cell wall where this MscS-specific feedback mechanism may be necessary.
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Affiliation(s)
- Ian Rowe
- Department of Biology, 2 Department of Chemistry and Biochemistry, and 3 Maryland Biophysics Program, University of Maryland, College Park, MD 20742
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18
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Hdud IM, Mobasheri A, Loughna PT. Effect of osmotic stress on the expression of TRPV4 and BKCa channels and possible interaction with ERK1/2 and p38 in cultured equine chondrocytes. Am J Physiol Cell Physiol 2014; 306:C1050-7. [DOI: 10.1152/ajpcell.00287.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The metabolic activity of articular chondrocytes is influenced by osmotic alterations that occur in articular cartilage secondary to mechanical load. The mechanisms that sense and transduce mechanical signals from cell swelling and initiate volume regulation are poorly understood. The purpose of this study was to investigate how the expression of two putative osmolyte channels [transient receptor potential vanilloid 4 (TRPV4) and large-conductance Ca2+-activated K+ (BKCa)] in chondrocytes is modulated in different osmotic conditions and to examine a potential role for MAPKs in this process. Isolated equine articular chondrocytes were subjected to anisosmotic conditions, and TRPV4 and BKCa channel expression and ERK1/2 and p38 MAPK protein phosphorylation were investigated using Western blotting. Results indicate that the TRPV4 channel contributes to the early stages of hypo-osmotic stress, while the BKCa channel is involved in responding to elevated intracellular Ca2+ and mediating regulatory volume decrease. ERK1/2 is phosphorylated by hypo-osmotic stress ( P < 0.001), and p38 MAPK is phosphorylated by hyperosmotic stress ( P < 0.001). In addition, this study demonstrates the importance of endogenous ERK1/2 phosphorylation in TRPV4 channel expression, where blocking ERK1/2 by a specific inhibitor (PD98059) prevented increased levels of the TRPV4 channel in cells exposed to hypo-osmotic stress and decreased TRPV4 channel expression to below control levels in iso-osmotic conditions ( P < 0.001).
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Affiliation(s)
- Ismail M. Hdud
- School of Veterinary Medicine and Science, Faculty of Medicine and Health Sciences, The University of Nottingham, Sutton Bonington Campus, Leicestershire, United Kingdom
| | - Ali Mobasheri
- School of Veterinary Medicine and Science, Faculty of Medicine and Health Sciences, The University of Nottingham, Sutton Bonington Campus, Leicestershire, United Kingdom
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Nottingham, United Kingdom
- Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, Arthritis Research UK Pain Centre, Queen's Medical Centre, Nottingham, United Kingdom; and
- Center of Excellence in Genomic Medicine Research (CEGMR), King Fahd Medical Research Center (KFMRC), King AbdulAziz University, Jeddah, Kingdom of Saudi Arabia
| | - Paul T. Loughna
- School of Veterinary Medicine and Science, Faculty of Medicine and Health Sciences, The University of Nottingham, Sutton Bonington Campus, Leicestershire, United Kingdom
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Nottingham, United Kingdom
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Abstract
TRP channels constitute a large superfamily of cation channel forming proteins, all related to the gene product of the transient receptor potential (trp) locus in Drosophila. In mammals, 28 different TRP channel genes have been identified, which exhibit a large variety of functional properties and play diverse cellular and physiological roles. In this article, we provide a brief and systematic summary of expression, function, and (patho)physiological role of the mammalian TRP channels.
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Affiliation(s)
- Maarten Gees
- Laboratory Ion Channel Research and TRP Research Platform Leuven (TRPLe), KU Leuven, Campus Gasthuisberg, Leuven, Belgium
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Abstract
The urothelium, which lines the inner surface of the renal pelvis, the ureters, and the urinary bladder, not only forms a high-resistance barrier to ion, solute and water flux, and pathogens, but also functions as an integral part of a sensory web which receives, amplifies, and transmits information about its external milieu. Urothelial cells have the ability to sense changes in their extracellular environment, and respond to chemical, mechanical and thermal stimuli by releasing various factors such as ATP, nitric oxide, and acetylcholine. They express a variety of receptors and ion channels, including P2X3 purinergic receptors, nicotinic and muscarinic receptors, and TRP channels, which all have been implicated in urothelial-neuronal interactions, and involved in signals that via components in the underlying lamina propria, such as interstitial cells, can be amplified and conveyed to nerves, detrusor muscle cells, and ultimately the central nervous system. The specialized anatomy of the urothelium and underlying structures, and the possible communication mechanisms from urothelial cells to various cell types within the bladder wall are described. Changes in the urothelium/lamina propria ("mucosa") produced by different bladder disorders are discussed, as well as the mucosa as a target for therapeutic interventions.
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Affiliation(s)
- Lori Birder
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
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Inada H, Procko E, Sotomayor M, Gaudet R. Structural and biochemical consequences of disease-causing mutations in the ankyrin repeat domain of the human TRPV4 channel. Biochemistry 2012; 51:6195-206. [PMID: 22702953 PMCID: PMC3413242 DOI: 10.1021/bi300279b] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The TRPV4 calcium-permeable cation channel plays important
physiological
roles in osmosensation, mechanosensation, cell barrier formation,
and bone homeostasis. Recent studies reported that mutations in TRPV4,
including some in its ankyrin repeat domain (ARD), are associated
with human inherited diseases, including neuropathies and skeletal
dysplasias, probably because of the increased constitutive activity
of the channel. TRPV4 activity is regulated by the binding of calmodulin
and small molecules such as ATP to the ARD at its cytoplasmic N-terminus.
We determined structures of ATP-free and -bound forms of human TRPV4-ARD
and compared them with available TRPV-ARD structures. The third inter-repeat
loop region (Finger 3 loop) is flexible and may act as a switch to
regulate channel activity. Comparisons of TRPV-ARD structures also
suggest an evolutionary link between ARD structure and ATP binding
ability. Thermal stability analyses and molecular dynamics simulations
suggest that ATP increases stability in TRPV-ARDs that can bind ATP.
Biochemical analyses of a large panel of TRPV4-ARD mutations associated
with human inherited diseases showed that some impaired thermal stability
while others weakened ATP binding ability, suggesting molecular mechanisms
for the diseases.
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Affiliation(s)
- Hitoshi Inada
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA
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Mergler S, Garreis F, Sahlmüller M, Lyras EM, Reinach PS, Dwarakanath A, Paulsen F, Pleyer U. Calcium regulation by thermo- and osmosensing transient receptor potential vanilloid channels (TRPVs) in human conjunctival epithelial cells. Histochem Cell Biol 2012; 137:743-61. [PMID: 22327830 DOI: 10.1007/s00418-012-0924-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2012] [Indexed: 11/28/2022]
Abstract
Transient receptor potential vanilloid (TRPV) channels respond to polymodal stresses to induce pain, inflammation and tissue fibrosis. In this study, we probed for their functional expression in human conjunctival epithelial (HCjE) cells and ex vivo human conjunctivas. Notably, patients suffering from dry eye syndrome experience the same type of symptomology induced by TRPV channel activation in other ocular tissues. TRPV gene and protein expression were determined by RT-PCR and immunohistochemistry in HCjE cells and human conjunctivas (body donors). The planar patch-clamp technique was used to record nonselective cation channel currents. Ca(2+) transients were monitored in fura-2 loaded cells. Cultivated HCjE cells and human conjunctiva express TRPV1, TRPV2, and TRPV4 mRNA. TRPV1 and TRPV4 localization was identified in human conjunctiva. Whereas the TRPV1 agonist capsaicin (CAP) (5-20 μM) -induced Ca(2+) transients were blocked by capsazepine (CPZ) (10 μM), the TRPV4 activator 4α-PDD (10 μM) -induced Ca(2+) increases were reduced by ruthenium-red (RuR) (20 μM). Different heating (<40°C or >43°C) led to Ca(2+) increases, which were also reduced by RuR. Hypotonic challenges of either 25 or 50% induced Ca(2+) transients and nonselective cation channel currents. In conclusion, conjunctiva express TRPV1, TRPV2, and TRPV4 channels which may provide novel drug targets for dry eye therapeutics. Their usage may have fewer side effects than those currently encountered with less selective drugs.
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Affiliation(s)
- Stefan Mergler
- Department of Ophthalmology, Campus Virchow-Clinic, Charité, Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
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Mergler S, Valtink M, Taetz K, Sahlmüller M, Fels G, Reinach PS, Engelmann K, Pleyer U. Characterization of transient receptor potential vanilloid channel 4 (TRPV4) in human corneal endothelial cells. Exp Eye Res 2011; 93:710-9. [DOI: 10.1016/j.exer.2011.09.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 08/29/2011] [Accepted: 09/07/2011] [Indexed: 11/26/2022]
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Abstract
The urinary bladder "mucosa" or innermost portion of the bladder is composed of transitional epithelium, basement membrane, and the lamina propria. This chapter reviews the specialized anatomy of the bladder epithelium (urothelium) and speculates on possible communication mechanisms from urothelial cells to various cell types within the bladder wall. For example, beyond serving as a simple barrier, there is growing evidence that the urinary bladder urothelium exhibits specialized sensory properties and plays a key role in the detection and transmission of both physiological and nociceptive stimuli. Findings from a number of studies suggest that the urothelium exhibits both "sensor" (expressing receptors/ion channels capable of responding to thermal, mechanical, and chemical stimuli) and "transducer" (ability to release chemicals) properties. Thus, urothelial cells exhibit the ability to sense changes in their extracellular environment including the ability to respond to chemical, mechanical, and thermal stimuli that may communicate the state of the urothelial environment to the underlying nervous and muscular systems.
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Affiliation(s)
- Lori A Birder
- Department of Medicine and Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
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Clark AL, Votta BJ, Kumar S, Liedtke W, Guilak F. Chondroprotective role of the osmotically sensitive ion channel transient receptor potential vanilloid 4: age- and sex-dependent progression of osteoarthritis in Trpv4-deficient mice. ACTA ACUST UNITED AC 2010; 62:2973-83. [PMID: 20583100 DOI: 10.1002/art.27624] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Mechanical loading significantly influences the physiology and pathology of articular cartilage, although the mechanisms of mechanical signal transduction are not fully understood. Transient receptor potential vanilloid 4 (TRPV4) is a Ca(++)-permeable ion channel that is highly expressed by articular chondrocytes and can be gated by osmotic and mechanical stimuli. The goal of this study was to determine the role of Trpv4 in the structure of the mouse knee joint and to determine whether Trpv4(-/-) mice exhibit altered Ca(++) signaling in response to osmotic challenge. METHODS Knee joints of Trpv4(-/-) mice were examined histologically and by microfocal computed tomography for osteoarthritic changes and bone structure at ages 4, 6, 9, and 12 months. Fluorescence imaging was used to quantify chondrocytic Ca(++) signaling within intact femoral cartilage in response to osmotic stimuli. RESULTS Deletion of Trpv4 resulted in severe osteoarthritic changes, including cartilage fibrillation, eburnation, and loss of proteoglycans, that were dependent on age and male sex. Subchondral bone volume and calcified meniscal volume were greatly increased, again in male mice. Chondrocytes from Trpv4(+/+) mice demonstrated significant Ca(++) responses to hypo-osmotic stress but not to hyperosmotic stress. The response to hypo-osmotic stress or to the TRPV4 agonist 4α-phorbol 12,13-didecanoate was eliminated in Trpv4(-/-) mice. CONCLUSION Deletion of Trpv4 leads to a lack of osmotically induced Ca(++) signaling in articular chondrocytes, accompanied by progressive, sex-dependent increases in bone density and osteoarthritic joint degeneration. These findings suggest a critical role for TRPV4-mediated Ca(++) signaling in the maintenance of joint health and normal skeletal structure.
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Aure MH, Røed A, Galtung HK. Intracellular Ca2+ responses and cell volume regulation upon cholinergic and purinergic stimulation in an immortalized salivary cell line. Eur J Oral Sci 2010; 118:237-44. [PMID: 20572856 DOI: 10.1111/j.1600-0722.2010.00738.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The water channel aquaporin 5 (AQP5) seems to play a key role in salivary fluid secretion and appears to be critical in the cell volume regulation of acinar cells. Recently, the cation channel transient potential vanilloid receptor 4 (TRPV4) was shown to be functionally connected to AQP5 and also to cell volume regulation in salivary glands. We used the Simian virus 40 (SV40) immortalized cell line SMG C10 from the rat submandibular salivary gland to investigate the effect of ATP and the neurotransmitter analogue carbachol on Ca(2+) signalling and cell volume regulation, as well as the involvement of TRPV4 in the responses. We used fura-2-AM imaging, cell volume measurements, and western blotting. Both carbachol and ATP increased the concentration of intracellular Ca(2+), but no volume changes could be measured. Inhibition of TRPV4 with ruthenium red impaired both ATP- and carbachol-stimulated Ca(2+) signals. Peak Ca(2+) signalling during hyposmotic exposure was significantly decreased following inhibition of TRPV4, while the cells' ability to volume regulate appeared to be unaffected. These results show that in the SMG C10 cells, simulation of nervous stimulation did not induce cell swelling, although the cells had intact volume regulatory mechanisms. Furthermore, even though Ca(2+) signals were not needed for this volume regulation, TRPV4 seems to play a role during ATP and carbachol stimulation.
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Affiliation(s)
- Marit H Aure
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Blindern, Oslo, Norway
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Identifying the Ion Channels Responsible for Signaling Gastro-Intestinal Based Pain. Pharmaceuticals (Basel) 2010; 3:2768-2798. [PMID: 27713376 PMCID: PMC4034097 DOI: 10.3390/ph3092768] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 08/05/2010] [Accepted: 08/20/2010] [Indexed: 12/20/2022] Open
Abstract
We are normally unaware of the complex signalling events which continuously occur within our internal organs. Most of us only become cognisant when sensations of hunger, fullness, urgency or gas arise. However, for patients with organic and functional bowel disorders pain is an unpleasant and often debilitating reminder. Furthermore, chronic pain still represents a large unmet need for clinical treatment. Consequently, chronic pain has a considerable economic impact on health care systems and the afflicted individuals. In order to address this need we must understand how symptoms are generated within the gut, the molecular pathways responsible for generating these signals and how this process changes in disease states.
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Everaerts W, Nilius B, Owsianik G. The vanilloid transient receptor potential channel TRPV4: from structure to disease. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2009; 103:2-17. [PMID: 19835908 DOI: 10.1016/j.pbiomolbio.2009.10.002] [Citation(s) in RCA: 214] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 10/07/2009] [Indexed: 12/19/2022]
Abstract
The Transient Receptor Potential Vanilloid 4 channel, TRPV4, is a Ca(2+) and Mg(2+) permeable non-selective cation channel involved in many different cellular functions. It is activated by a variety of physical and chemical stimuli, including heat, mechano-stimuli, endogenous substances such as arachidonic acid and its cytochrome P450-derived metabolites (epoxyeicosatrienoic acids), endocannabinoids (anandamide and 2-arachidonoylglycerol), as well as synthetic alpha-phorbol derivatives. Recently, TRPV4 has been characterized as an important player modulating osteoclast differentiation in bone remodelling and as a urothelial mechanosensor that controls normal voiding. Several TRPV4 gain-of-function mutations are shown to cause autosomal-dominant bone dysplasias such as brachyolmia and Koszlowski disease. In this review we comprehensively describe the structural, biophysical and (patho)physiological properties of the TRPV4 channel and we summarize the current knowledge about the role of TRPV4 in the pathogenesis of several diseases.
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Affiliation(s)
- Wouter Everaerts
- Department of Molecular Cell Biology, Laboratory Ion Channel Research, Campus Gasthuisberg, KULeuven, Herestraat 49, bus 802, B-3000 Leuven, Belgium
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Abstract
Beyond serving as a simple barrier, there is growing evidence that the urinary bladder urothelium exhibits specialized sensory properties and play a key role in the detection and transmission of both physiological and nociceptive stimuli. These urothelial cells exhibit the ability to sense changes in their extracellular environment including the ability to respond to chemical, mechanical and thermal stimuli that may communicate the state of the urothelial environment to the underlying nervous and muscular systems. Here, we review the specialized anatomy of the urothelium and speculate on possible communication mechanisms from urothelial cells to various cell types within the bladder wall.
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Affiliation(s)
- Lori A Birder
- University of Pittsburgh School of Medicine, A 1207 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261, USA.
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Colsoul B, Nilius B, Vennekens R. On the putative role of transient receptor potential cation channels in asthma. Clin Exp Allergy 2009; 39:1456-66. [PMID: 19624522 DOI: 10.1111/j.1365-2222.2009.03315.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The mammalian transient receptor potential (TRP) superfamily consists of 28 mammalian TRP cation channels, which can be subdivided into six main subfamilies: the TRPC ('Canonical'), TRPV ('Vanilloid'), TRPM ('Melastatin'), TRPP ('Polycystin'), TRPML ('Mucolipin') and the TRPA ('Ankyrin') groups. Increasing evidence has accumulated during the previous few years that links TRP channels to the cause of several diseases or to critically influence and/or determine their progress. This review focuses on the possible role of TRP channels in the aetiology of asthmatic lung disease.
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Affiliation(s)
- B Colsoul
- Laboratory Ion Channel Research, Department of Molecular Cell Biology, KU Leuven, Leuven, Belgium
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Hasler U. Controlled aquaporin-2 expression in the hypertonic environment. Am J Physiol Cell Physiol 2009; 296:C641-53. [PMID: 19211910 DOI: 10.1152/ajpcell.00655.2008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The corticomedullary osmolality gradient is the driving force for water reabsorption occurring in the kidney. In the collecting duct, this gradient allows luminal water to move across aquaporin (AQP) water channels, thereby increasing urine concentration. However, this same gradient exposes renal cells to great osmotic challenges. These cells must constantly adapt to fluctuations of environmental osmolality that challenge cell volume and incite functional change. This implies profound alterations of cell phenotype regarding water permeability. AQP2 is an essential component of the urine concentration mechanism whose controlled expression dictates apical water permeability of collecting duct principal cells. This review focuses on changes of AQP2 abundance and trafficking in hypertonicity-challenged cells. Intracellular mechanisms governing these events are discussed and the biological relevance of altered AQP2 expression by hypertonicity is outlined.
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Affiliation(s)
- Udo Hasler
- Service de Néphrologie, Fondation pour Recherches Médicales, 64 Ave. de la Roseraie, CH-1211, Geneva 4, Switzerland.
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Carreño FR, Ji LL, Cunningham JT. Altered central TRPV4 expression and lipid raft association related to inappropriate vasopressin secretion in cirrhotic rats. Am J Physiol Regul Integr Comp Physiol 2008; 296:R454-66. [PMID: 19091909 DOI: 10.1152/ajpregu.90460.2008] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Inappropriate vasopressin (AVP) release causes dilutional hyponatremia in many pathophysiological states such as cirrhosis. The central molecular mechanisms that mediate inappropriate AVP release are unknown. We tested the hypothesis that changes in the expression or trafficking of TRPV4 in the central nervous system may contribute to inappropriate AVP release in the bile duct ligation (BDL) model of cirrhosis in the rat. Four weeks after surgery, BDL rats demonstrated significantly increased plasma vasopressin and plasma renin activity (PRA), hypervolemia, and decreased plasma osmolality. These effects were blocked by providing BDL rats with 2% saline to drink for 15 days. TRPV4 protein expression was significantly increased in brain punches from BDL rats containing the supraoptic nucleus (SON) of the hypothalamus (100% +/- 11 to 157% +/- 4.8), and this effect was blocked in BDL rats given saline. Immunohistochemistry demonstrated a significant increase in TRPV4-positive cells and the percentage of AVP neurons that also were TRPV4-positive in the SON of BDL rats. In the hypothalamus of BDL rats, TRPV4 lipid raft association increased compared with sham (from 100% +/- 2.1 to 326.1% +/- 16). This effect was significantly attenuated in BDL rats given 2% saline to drink (174% +/- 11). In the brain stem, TRPV4 lipid raft association was reduced by BDL and inversely related to plasma AVP and PRA. We speculate that changes in TRPV4 expression and compartmentalization within lipid rafts could contribute to a feed-forward mechanism related to AVP release in cirrhosis.
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Affiliation(s)
- Flávia Regina Carreño
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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Transient receptor potential vanilloid channels in hypertension, inflammation, and end organ damage: an imminent target of therapy for cardiovascular disease? Curr Opin Cardiol 2008; 23:356-63. [PMID: 18520720 DOI: 10.1097/hco.0b013e32830460ad] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE OF REVIEW The possible role of several neurohormonal factors in pathogenesis of hypertension has been studied extensively both in humans and in experimental animal models. However, controversial data from some previous studies are indecisive and call for reassessment and development of new targets. This mini-review presents some of the most recent findings about the role of transient receptor potential vanilloid type 1 channels in the development of hypertension and its pathology. RECENT FINDINGS The transient receptor potential vanilloid type 1, channel activated by novel endovanilloids or altered pH, temperature, and/or local hemodynamics, may serve as a distinct molecular sensor detecting sodium and water balance and may play a role in preventing salt-induced hypertension and tissue damage. Impairment of the function of the transient receptor potential vanilloid type 1 channels may contribute to increased salt sensitivity, inflammation, and end organ damage. SUMMARY Emerging evidence indicates that the transient receptor potential vanilloid type 1 channel plays a key role in cardiovascular health and disease by acting as a sensor and regulator of cardiovascular homeostasis and a protector against cardiovascular injury. Given the huge population who suffers from cardiovascular disease, the study of the transient receptor potential vanilloid channels may improve our understanding of pathogenesis of several common cardiovascular disorders and may lead to the development of therapy for hypertension, inflammation, and organ damage.
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Kakigi A, Nishimura M, Takeda T, Taguchi D, Nishioka R. Expression of aquaporin1, 3, and 4, NKCC1, and NKCC2 in the human endolymphatic sac. Auris Nasus Larynx 2008; 36:135-9. [PMID: 18606512 DOI: 10.1016/j.anl.2008.04.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 03/21/2008] [Accepted: 04/13/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To locate aquaporin (AQP) 1, 3, and 4, Na-K-2Cl cotransporter (NKCC) 1 and 2 in the human endolymphatic sac (ES). METHODS A sample of human ES was harvested during the removal of vestibular schwannoma via the translabyrinthine approach. The sample was immediately fixed in 4% paraformaldehyde and embedded in OCT compound. Immunohistochemistry was performed with AQP1, 3, and 4, NKCC1, and NKCC2 polyclonal antibodies. RESULTS AQP1, AQP3, and NKCC2 were strongly expressed in the epithelial layer of the ES. AQP4 and NKCC1 were weakly expressed in the epithelial layer of the ES. CONCLUSIONS As it is impossible to perform quantitative analysis based on the fluorescence intensity of each immunoreactivity, we have presented the existence of AQP1, 3, and 4, NKCC1, and NKCC2 in the ES. The expression of NKCC1 and 2 indicated that the ES may have both secretory and adsorptive functions to maintain the homeostasis of endolymph.
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Affiliation(s)
- Akinobu Kakigi
- Department of Otolaryngology, Kochi Medical School, Nankoku, Japan.
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Marshall W, Katoh F, Main H, Sers N, Cozzi R. Focal adhesion kinase and β1 integrin regulation of Na+, K+, 2Cl− cotransporter in osmosensing ion transporting cells of killifish, Fundulus heteroclitus. Comp Biochem Physiol A Mol Integr Physiol 2008; 150:288-300. [DOI: 10.1016/j.cbpa.2008.03.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 03/13/2008] [Accepted: 03/17/2008] [Indexed: 12/31/2022]
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Abstract
This article discusses three largely unrecognized aspects related to fluid movement in ocular tissues; namely, (a) the dynamic changes in water permeability observed in corneal and conjunctival epithelia under anisotonic conditions, (b) the indications that the fluid transport rate exhibited by the ciliary epithelium is insufficient to explain aqueous humor production, and (c) the evidence for fluid movement into and out of the lens during accommodation. We have studied each of these subjects in recent years and present an evaluation of our data within the context of the results of others who have also worked on electrolyte and fluid transport in ocular tissues. We propose that (1) the corneal and conjunctival epithelia, with apical aspects naturally exposed to variable tonicities, are capable of regulating their water permeabilities as part of the cell-volume regulatory process, (2) fluid may directly enter the anterior chamber of the eye across the anterior surface of the iris, thereby representing an additional entry pathway for aqueous humor production, and (3) changes in lens volume occur during accommodation, and such changes are best explained by a net influx and efflux of fluid.
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Affiliation(s)
- Oscar A Candia
- Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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Raoux M, Rodat-Despoix L, Azorin N, Giamarchi A, Hao J, Maingret F, Crest M, Coste B, Delmas P. Mechanosensor Channels in Mammalian Somatosensory Neurons. SENSORS 2007; 7:1667-1682. [PMID: 28903189 PMCID: PMC3841838 DOI: 10.3390/s7091667] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 08/31/2007] [Indexed: 12/11/2022]
Abstract
Mechanoreceptive sensory neurons innervating the skin, skeletal muscles and viscera signal both innocuous and noxious information necessary for proprioception, touch and pain. These neurons are responsible for the transduction of mechanical stimuli into action potentials that propagate to the central nervous system. The ability of these cells to detect mechanical stimuli impinging on them relies on the presence of mechanosensitive channels that transduce the external mechanical forces into electrical and chemical signals. Although a great deal of information regarding the molecular and biophysical properties of mechanosensitive channels in prokaryotes has been accumulated over the past two decades, less is known about the mechanosensitive channels necessary for proprioception and the senses of touch and pain. This review summarizes the most pertinent data on mechanosensitive channels of mammalian somatosensory neurons, focusing on their properties, pharmacology and putative identity.
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Affiliation(s)
- Matthieu Raoux
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - Lise Rodat-Despoix
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - Nathalie Azorin
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - Aurélie Giamarchi
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - Jizhe Hao
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - François Maingret
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - Marcel Crest
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - Bertrand Coste
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
| | - Patrick Delmas
- Laboratoire de Neurophysiologie Cellulaire, Centre National de la Recherche Scientifique UMR 6150, Université de la Méditerranée, Marseille, France.
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Birder LA. TRPs in bladder diseases. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1772:879-84. [PMID: 17560087 PMCID: PMC3713460 DOI: 10.1016/j.bbadis.2007.04.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 04/11/2007] [Accepted: 04/12/2007] [Indexed: 11/27/2022]
Abstract
This review attempts to provide an overview of the current knowledge of TRP proteins and their possible role in bladder function and disease. At present, there are 28 transient receptor potential (TRP) channels (subdivided into 7 categories or families) which are involved in a number of functions [G.A. Hicks, TRP channels as therapeutic targets: hot property, or time to cool down? Neurogastroenterology and Motility 18, (2006) 590-594., J.D. Levine, N. Alessandri-Haber, TRP channels: targets for the relief of pain, Biochimica et Biophysica Acta 1772, (2007) 989-1003.]. Of those belonging to the group 1 subfamily, a number of TRPV, TRPM and TRPA proteins associated with osmoregulation, thermal, chemical and mechanical signaling mechanisms have been shown to be expressed within the lower urinary tract. Though the biological role of many of these channels in urinary bladder function still remains elusive, TRPV1 is by far the best characterized and is thought to be involved in a number of bladder disorders [A. Szallasi, P.M. Blumberg, Vanilloid (Capsaicin) Receptors and Mechanisms, Pharmacological Reviews 51, (1999) 150-221., I. Nagy, P. Santha, G. Jansco, L. Urban, The role of the vanilloid (capsaicin) receptor (TRPV1) in physiology and pathology, European Journal of Pharmacology 500, (2004) 351-369.].
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Affiliation(s)
- Lori A Birder
- University of Pittsburgh School of Medicine, Department of Medicine and Pharmacology, A 1207 Scaife Hall, Pittsburgh, PA 15261, USA.
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Taguchi D, Takeda T, Kakigi A, Takumida M, Nishioka R, Kitano H. Expressions of Aquaporin-2, Vasopressin Type 2 Receptor, Transient Receptor Potential Channel Vanilloid (TRPV)1, and TRPV4 in the Human Endolymphatic Sac. Laryngoscope 2007; 117:695-8. [PMID: 17415141 DOI: 10.1097/mlg.0b013e318031c802] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To localize aquaporin (AQP)2, vasopressin type 2 receptor (V2-R), and transient receptor potential channel vanilloid subfamily 1, 4 (TRPV1, TRPV4) in the human endolymphatic sac (ES). METHODS Three samples of human ES were sampled during the removal of vestibular schwannoma by way of the translabyrinthine approach. The samples were immediately fixed in 4% paraformaldehyde and embedded in OCT compound; immunohistochemistry was performed with AQP2, V2-R, TRPV1, and TRPV4 polyclonal antibodies. RESULTS AQP2, V2-R, TRPV1, and TRPV4 proteins were detected in the epithelial layer of the ES but were not observed in connective tissue around the ES. TRPV1 was also expressed in blood vascular endothelial cells of the connective tissue of ES. CONCLUSIONS AQP2, V2-R, and TRPV4 were expressed in the luminal epithelium of human ES. The same characteristic distribution of water and ion channels is seen in the kidney, where a significant amount of fluid is filtrated and resorbed. ES probably plays an active role in the homeostasis of the endolymph.
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Affiliation(s)
- Daizo Taguchi
- Department of Otolaryngology, Kochi Medical School, Nankoku, Kochi, Japan.
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Nilius B, Owsianik G, Voets T, Peters JA. Transient receptor potential cation channels in disease. Physiol Rev 2007; 87:165-217. [PMID: 17237345 DOI: 10.1152/physrev.00021.2006] [Citation(s) in RCA: 1041] [Impact Index Per Article: 61.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The transient receptor potential (TRP) superfamily consists of a large number of cation channels that are mostly permeable to both monovalent and divalent cations. The 28 mammalian TRP channels can be subdivided into six main subfamilies: the TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin), TRPML (mucolipin), and the TRPA (ankyrin) groups. TRP channels are expressed in almost every tissue and cell type and play an important role in the regulation of various cell functions. Currently, significant scientific effort is being devoted to understanding the physiology of TRP channels and their relationship to human diseases. At this point, only a few channelopathies in which defects in TRP genes are the direct cause of cellular dysfunction have been identified. In addition, mapping of TRP genes to susceptible chromosome regions (e.g., translocations, breakpoint intervals, increased frequency of polymorphisms) has been considered suggestive of the involvement of these channels in hereditary diseases. Moreover, strong indications of the involvement of TRP channels in several diseases come from correlations between levels of channel expression and disease symptoms. Finally, TRP channels are involved in some systemic diseases due to their role as targets for irritants, inflammation products, and xenobiotic toxins. The analysis of transgenic models allows further extrapolations of TRP channel deficiency to human physiology and disease. In this review, we provide an overview of the impact of TRP channels on the pathogenesis of several diseases and identify several TRPs for which a causal pathogenic role might be anticipated.
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Affiliation(s)
- Bernd Nilius
- Department of Physiology, Campus Gasthuisberg, KULeuven, Leuven, Belgium.
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Abstract
Sensory neurons innervating the skin encode the familiar sensations of temperature, touch and pain. An explosion of progress has revealed unanticipated cellular and molecular complexity in these senses. It is now clear that perception of a single stimulus, such as heat, requires several transduction mechanisms. Conversely, a given protein may contribute to multiple senses, such as heat and touch. Recent studies have also led to the surprising insight that skin cells might transduce temperature and touch. To break the code underlying somatosensation, we must therefore understand how the skin's sensory functions are divided among signalling molecules and cell types.
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Affiliation(s)
- Ellen A Lumpkin
- Departments of Neuroscience, Molecular Physiology & Biophysics and Molecular & Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
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Nilius B. TRP channels in disease. Biochim Biophys Acta Mol Basis Dis 2007; 1772:805-12. [PMID: 17368864 DOI: 10.1016/j.bbadis.2007.02.002] [Citation(s) in RCA: 218] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Accepted: 02/01/2007] [Indexed: 11/22/2022]
Abstract
"Transient receptor potential" cation channels (TRP channels) play a unique role as cell sensors, are involved in a plethora of Ca(2+)-mediated cell functions, and play a role as "gate-keepers" in many homeostatic processes such as Ca(2+) and Mg(2+) reabsorption. The variety of functions to which TRP channels contribute and the polymodal character of their activation predict that failures in correct channel gating or permeation will likely contribute to complex pathophysiological mechanisms. Dysfunctions of TRPs cause human diseases but are also involved in a complex manner to contribute and determine the progress of several diseases. Contributions to this special issue discuss channelopathias for which mutations in TRP channels that induce "loss-" or "gain-of-function" of the channel and can be considered "disease-causing" have been identified. The role of TRPs will be further elucidated in complex diseases of the intestinal, renal, urogenital, respiratory, and cardiovascular systems. Finally, the role of TRPs will be discussed in neuronal diseases and neurodegenerative disorders.
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Affiliation(s)
- Bernd Nilius
- KU Leuven, Department of Molecular Cell Biology, Division of Physiology, Laboratory of Ion Channel Research, Campus Gasthuisberg, Herestraat 49, bus 802, B-3000 Leuven, Belgium.
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Pedersen SF, Nilius B. Transient Receptor Potential Channels in Mechanosensing and Cell Volume Regulation. Methods Enzymol 2007; 428:183-207. [PMID: 17875418 DOI: 10.1016/s0076-6879(07)28010-3] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Transient receptor potential (TRP) channels are unique cellular sensors responding to a wide variety of extra- and intracellular signals, including mechanical and osmotic stress. In recent years, TRP channels from multiple subfamilies have been added to the list of mechano- and/or osmosensitive channels, and it is becoming increasingly apparent that Ca(2+) influx via TRP channels plays a crucial role in the response to mechanical and osmotic perturbations in a wide range of cell types. Although the events translating mechanical and osmotic stimuli into regulation of TRP channels are still incompletely understood, the specific mechanisms employed vary between different TRP isoforms, and probably include changes in the tension and/or curvature of the lipid bilayer, changes in the cortical cytoskeleton, and signaling events such as lipid metabolism and protein phosphorylation/dephosphorylation. This chapter describes candidate mechanosensitive channels from mammalian TRP subfamilies, discusses inherent and technical issues potentially confounding evaluation of mechano- and/or osmosensitivity, and presents methods relevant to the study of TRP channel regulation by mechanical and osmotic stimuli and involvement in cell volume regulation.
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45
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Schwab A, Nechyporuk-Zloy V, Fabian A, Stock C. Cells move when ions and water flow. Pflugers Arch 2006; 453:421-32. [PMID: 17021798 DOI: 10.1007/s00424-006-0138-6] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Accepted: 07/09/2006] [Indexed: 12/22/2022]
Abstract
Cell migration is a process that plays an important role throughout the entire life span. It starts early on during embryogenesis and contributes to shaping our body. Migrating cells are involved in maintaining the integrity of our body, for instance, by defending it against invading pathogens. On the other side, migration of tumor cells may have lethal consequences when tumors spread metastatically. Thus, there is a strong interest in unraveling the cellular mechanisms underlying cell migration. The purpose of this review is to illustrate the functional importance of ion and water channels as part of the cellular migration machinery. Ion and water flow is required for optimal migration, and the inhibition or genetic ablation of channels leads to a marked impairment of migration. We briefly touch cytoskeletal mechanisms of migration as well as cell-matrix interactions. We then present some general principles by which channels can affect cell migration before we discuss each channel group separately.
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Affiliation(s)
- Albrecht Schwab
- Institut für Physiologie II, Universität Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany.
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Avelino A, Cruz F. TRPV1 (vanilloid receptor) in the urinary tract: expression, function and clinical applications. Naunyn Schmiedebergs Arch Pharmacol 2006; 373:287-99. [PMID: 16721555 DOI: 10.1007/s00210-006-0073-2] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Accepted: 04/10/2006] [Indexed: 01/08/2023]
Abstract
The transient receptor potential vanilloid subfamily 1 (TRPV1) is an ion channel activated by capsaicin, heat, protons and endogenous ligands such as anandamide. It is largely expressed in the urinary tract of mammals. Structures in which the receptor expression is firmly established include sensory fibers and urothelial cells, although the presence of TRPV1 in other cell types has been reported. As in other systems, pain perception was the first role attributed to TRPV1 in the urinary tract. However, it is now increasingly clear that TRPV1 also regulates the frequency of bladder reflex contractions, either through direct excitation of sensory fibers or through urothelial-sensory fiber cross talk involving the release of neuromediators from the epithelial cells. In addition, the recent identification of the receptor in urothelial and prostatic cancer cells raise the exciting hypothesis that TRPV1 is involved in cell differentiation. Desensitization of the receptor by capsaicin and resiniferatoxin has been investigated for therapeutic purposes. For the moment, lower urinary tract dysfunctions in which some benefit was obtained include painful bladder syndrome and overactive bladder of neurogenic and non-neurogenic origin. However, desensitization may become obsolete when non-toxic, potent TRPV1 antagonists become available.
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Affiliation(s)
- António Avelino
- Institute of Histology and Embryology, Faculty of Medicine of Porto, Alameda Hernani Monteiro, 4200-319 Porto, Portugal
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