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Li M, Xu J, Li L, Zhang L, Zuo Z, Feng Y, He X, Hu X. Voluntary wheel exercise improves glymphatic clearance and ameliorates colitis-associated cognitive impairment in aged mice by inhibiting TRPV4-induced astrocytic calcium activity. Exp Neurol 2024; 376:114770. [PMID: 38580155 DOI: 10.1016/j.expneurol.2024.114770] [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: 01/15/2024] [Revised: 03/08/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024]
Abstract
BACKGROUND AND OBJECTIVES Chronic colitis exacerbates neuroinflammation, contributing to cognitive impairment during aging, but the mechanism remains unclear. The polarity distribution of astrocytic aquaporin 4 (AQP4) is crucial for the glymphatic system, which is responsible for metabolite clearance in the brain. Physical exercise (PE) improves cognition in the aged. This study aims to investigate the protective mechanism of exercise in colitis-associated cognitive impairment. METHODS To establish a chronic colitis model, 18-month-old C57BL/6 J female mice received periodic oral administration of 1% wt/vol dextran sodium sulfate (DSS) in drinking water. The mice in the exercise group received four weeks of voluntary wheel exercise. High-throughput sequencing was conducted to screen for differentially expressed genes. Two-photon imaging was performed to investigate the function of the astrocytic calcium activity and in vivo intervention with TRPV4 inhibitor HC-067047. Further, GSK1016790A (GSK1), a TRPV4 agonist, was daily intraperitoneally injected during the exercise period to study the involvement of TRPV4 in PE protection. Colitis pathology was confirmed by histopathology. The novel object recognition (NOR) test, Morris water maze test (MWM), and open field test were performed to measure colitis-induced cognition and anxiety-like behavior. In vivo two-photon imaging and ex vivo imaging of fluorescent CSF tracers to evaluate the function of the glymphatic system. Immunofluorescence staining was used to detect the Aβ deposition, polarity distribution of astrocytic AQP4, and astrocytic phenotype. Serum and brain levels of the inflammatory cytokines were tested by Enzyme-linked immunosorbent assay (ELISA). The brain TUNEL assay was used to assess DNA damage. Expression of critical molecules was detected using Western blotting. RESULTS Voluntary exercise alleviates cognitive impairment and anxiety-like behavior in aged mice with chronic colitis, providing neuroprotection against neuronal damage and apoptosis. Additionally, voluntary exercise promotes the brain clearance of Aβ via increased glymphatic clearance. Mechanistically, exercise-induced beneficial effects may be attributed, in part, to the inhibition of TRPV4 expression and TRPV4-related calcium hyperactivity, subsequent promotion of AQP4 polarization, and modulation of astrocyte phenotype. CONCLUSION The present study reveals a novel role of voluntary exercise in alleviating colitis-related cognitive impairment and anxiety disorder, which is mediated by the promotion of AQP4 polarization and glymphatic clearance of Aβ via inhibition of TRPV4-induced astrocytic calcium hyperactivity.
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Affiliation(s)
- Mingyue Li
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jinghui Xu
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Lili Li
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Liying Zhang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Zejie Zuo
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Yifeng Feng
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Xiaofei He
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
| | - Xiquan Hu
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
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Gou R, Liu Y, Gou L, Mi S, Li X, Yang Y, Cheng X, Zhang Y. Transient Receptor Potential Channels in Sensory Mechanisms of the Lower Urinary Tract. Urol Int 2024:1-13. [PMID: 38657590 DOI: 10.1159/000538855] [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: 10/10/2023] [Accepted: 04/03/2024] [Indexed: 04/26/2024]
Abstract
BACKGROUND Urine storage and excretion require a network of interactions in the urinary tract and the central nervous system, which is mediated by a reservoir of water in the bladder and the outlet to the bladder neck, urethra, and external urethral sphincter. Through communicating and coordinating each other, micturition system eventually showed a switch-like activity pattern. SUMMARY At cervicothoracic and lumbosacral spine, the spinal reflex pathway of the lower urinary tract (LUT) received mechanosensory input from the urothelium to regulate the bladder contraction activity, thereby controlled urination voluntarily. Impairment of above-mentioned any level could result in lower urinary tract dysfunction, placed a huge burden on patients and society. Specific expression of purinergic receptors and transient receptor potential (TRP) channels are thought to play an important role in urinary excretion in the LUT. KEY MESSAGES This article reviewed the knowledge about the voiding reflex and described the role and function of TRP channels during voiding.
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Affiliation(s)
- Ruiqiang Gou
- The First Clinical Medical College, Lanzhou University, Lanzhou, China,
| | - Yuanyuan Liu
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
| | - Li Gou
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
| | - Shengyan Mi
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
| | - Xiaonan Li
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
| | - Yichen Yang
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
| | - Xiaorong Cheng
- The Second Hospital and Clinical Medical School, Lanzhou University, Lanzhou, China
| | - Yibao Zhang
- The Second Hospital and Clinical Medical School, Lanzhou University, Lanzhou, China
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Rezzani R, Favero G, Gianò M, Pinto D, Labanca M, van Noorden CJ, Rinaldi F. Transient Receptor Potential Channels in the Healthy and Diseased Blood-Brain Barrier. J Histochem Cytochem 2024; 72:199-231. [PMID: 38590114 PMCID: PMC11020746 DOI: 10.1369/00221554241246032] [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: 09/19/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
The large family of transient receptor potential (TRP) channels are integral membrane proteins that function as environmental sensors and act as ion channels after activation by mechanical (touch), physical (heat, pain), and chemical stimuli (pungent compounds such as capsaicin). Most TRP channels are localized in the plasma membrane of cells but some of them are localized in membranes of organelles and function as intracellular Ca2+-ion channels. TRP channels are involved in neurological disorders but their precise role(s) and relevance in these disorders are not clear. Endothelial cells of the blood-brain barrier (BBB) express TRP channels such as TRP vanilloid 1-4 and are involved in thermal detection by regulating BBB permeability. In neurological disorders, TRP channels in the BBB are responsible for edema formation in the brain. Therefore, drug design to modulate locally activity of TRP channels in the BBB is a hot topic. Today, the application of TRP channel antagonists against neurological disorders is still limited.
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Affiliation(s)
- Rita Rezzani
- Division of Anatomy and Physiopathology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Interdipartimental University Center of Research Adaption and Regeneration of Tissues and Organs - ARTO, University of Brescia, Brescia, Italy
- Italian Society for the Study of Orofacial Pain (Società Italiana Studio Dolore Orofacciale - SISDO), Brescia, Italy
| | - Gaia Favero
- Division of Anatomy and Physiopathology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Interdipartimental University Center of Research Adaption and Regeneration of Tissues and Organs - ARTO, University of Brescia, Brescia, Italy
| | - Marzia Gianò
- Division of Anatomy and Physiopathology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Daniela Pinto
- Human Microbiome Advanced Project Institute, Milan, Italy
| | - Mauro Labanca
- Division of Anatomy and Physiopathology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Italian Society for the Study of Orofacial Pain (Società Italiana Studio Dolore Orofacciale - SISDO), Brescia, Italy
| | - Cornelis J.F. van Noorden
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Fabio Rinaldi
- Human Microbiome Advanced Project Institute, Milan, Italy
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4
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Zhang X, Zhang Y, Su Q, Liu Y, Li Z, Yong VW, Xue M. Ion Channel Dysregulation Following Intracerebral Hemorrhage. Neurosci Bull 2024; 40:401-414. [PMID: 37755675 PMCID: PMC10912428 DOI: 10.1007/s12264-023-01118-6] [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: 01/27/2023] [Accepted: 06/14/2023] [Indexed: 09/28/2023] Open
Abstract
Injury to the brain after intracerebral hemorrhage (ICH) results from numerous complex cellular mechanisms. At present, effective therapy for ICH is limited and a better understanding of the mechanisms of brain injury is necessary to improve prognosis. There is increasing evidence that ion channel dysregulation occurs at multiple stages in primary and secondary brain injury following ICH. Ion channels such as TWIK-related K+ channel 1, sulfonylurea 1 transient receptor potential melastatin 4 and glutamate-gated channels affect ion homeostasis in ICH. They in turn participate in the formation of brain edema, disruption of the blood-brain barrier, and the generation of neurotoxicity. In this review, we summarize the interaction between ions and ion channels, the effects of ion channel dysregulation, and we discuss some therapeutics based on ion-channel modulation following ICH.
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Affiliation(s)
- Xiangyu Zhang
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, 450000, China
| | - Yan Zhang
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, 450000, China
| | - Qiuyang Su
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, 450000, China
| | - Yang Liu
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, 450000, China
| | - Zhe Li
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, 450000, China
| | - V Wee Yong
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, University of Calgary, Calgary, AB, T2N 1N4, Canada.
| | - Mengzhou Xue
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China.
- Academy of Medical Science, Zhengzhou University, Zhengzhou, 450000, China.
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5
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Kwon DH, Zhang F, McCray BA, Feng S, Kumar M, Sullivan JM, Im W, Sumner CJ, Lee SY. TRPV4-Rho GTPase complex structures reveal mechanisms of gating and disease. Nat Commun 2023; 14:3732. [PMID: 37353484 PMCID: PMC10290081 DOI: 10.1038/s41467-023-39345-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 06/08/2023] [Indexed: 06/25/2023] Open
Abstract
Crosstalk between ion channels and small GTPases is critical during homeostasis and disease, but little is known about the structural underpinnings of these interactions. TRPV4 is a polymodal, calcium-permeable cation channel that has emerged as a potential therapeutic target in multiple conditions. Gain-of-function mutations also cause hereditary neuromuscular disease. Here, we present cryo-EM structures of human TRPV4 in complex with RhoA in the ligand-free, antagonist-bound closed, and agonist-bound open states. These structures reveal the mechanism of ligand-dependent TRPV4 gating. Channel activation is associated with rigid-body rotation of the intracellular ankyrin repeat domain, but state-dependent interaction with membrane-anchored RhoA constrains this movement. Notably, many residues at the TRPV4-RhoA interface are mutated in disease and perturbing this interface by introducing mutations into either TRPV4 or RhoA increases TRPV4 channel activity. Together, these results suggest that RhoA serves as an auxiliary subunit for TRPV4, regulating TRPV4-mediated calcium homeostasis and disruption of TRPV4-RhoA interactions can lead to TRPV4-related neuromuscular disease. These insights will help facilitate TRPV4 therapeutics development.
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Affiliation(s)
- Do Hoon Kwon
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Feng Zhang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Brett A McCray
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Shasha Feng
- Departments of Biological Sciences, Chemistry, and Bioengineering, Lehigh University, Bethlehem, PA, 18015, USA
| | - Meha Kumar
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Jeremy M Sullivan
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Wonpil Im
- Departments of Biological Sciences, Chemistry, and Bioengineering, Lehigh University, Bethlehem, PA, 18015, USA
| | - Charlotte J Sumner
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA.
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Blazer-Yost BL. Consideration of Kinase Inhibitors for the Treatment of Hydrocephalus. Int J Mol Sci 2023; 24:ijms24076673. [PMID: 37047646 PMCID: PMC10094860 DOI: 10.3390/ijms24076673] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 04/07/2023] Open
Abstract
Hydrocephalus is a devastating condition characterized by excess cerebrospinal fluid (CSF) in the brain. Currently, the only effective treatment is surgical intervention, usually involving shunt placement, a procedure prone to malfunction, blockage, and infection that requires additional, often repetitive, surgeries. There are no long-term pharmaceutical treatments for hydrocephalus. To initiate an intelligent drug design, it is necessary to understand the biochemical changes underlying the pathology of this chronic condition. One potential commonality in the various forms of hydrocephalus is an imbalance in fluid–electrolyte homeostasis. The choroid plexus, a complex tissue found in the brain ventricles, is one of the most secretory tissues in the body, producing approximately 500 mL of CSF per day in an adult human. In this manuscript, two key transport proteins of the choroid plexus epithelial cells, transient receptor potential vanilloid 4 and sodium, potassium, 2 chloride co-transporter 1, will be considered. Both appear to play key roles in CSF production, and their inhibition or genetic manipulation has been shown to affect CSF volume. As with most transporters, these proteins are regulated by kinases. Therefore, specific kinase inhibitors are also potential targets for the development of pharmaceuticals to treat hydrocephalus.
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Affiliation(s)
- Bonnie L. Blazer-Yost
- Biology Department, Indiana University—Purdue University, 723 West Michigan Street, Indianapolis, IN 46202, USA
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7
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Zeng ML, Kong S, Chen TX, Peng BW. Transient Receptor Potential Vanilloid 4: a Double-Edged Sword in the Central Nervous System. Mol Neurobiol 2023; 60:1232-1249. [PMID: 36434370 DOI: 10.1007/s12035-022-03141-6] [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: 08/09/2022] [Accepted: 11/17/2022] [Indexed: 11/26/2022]
Abstract
Transient receptor potential vanilloid 4 (TRPV4) is a nonselective cation channel that can be activated by diverse stimuli, such as heat, mechanical force, hypo-osmolarity, and arachidonic acid metabolites. TRPV4 is widely expressed in the central nervous system (CNS) and participates in many significant physiological processes. However, accumulative evidence has suggested that deficiency, abnormal expression or distribution, and overactivation of TRPV4 are involved in pathological processes of multiple neurological diseases. Here, we review the latest studies concerning the known features of this channel, including its expression, structure, and its physiological and pathological roles in the CNS, proposing an emerging therapeutic strategy for CNS diseases.
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Affiliation(s)
- Meng-Liu Zeng
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Taikang Medical School (School of Basic Medical Sciences), Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China.,Medical Science Research Center, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Shuo Kong
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Taikang Medical School (School of Basic Medical Sciences), Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China
| | - Tao-Xiang Chen
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Taikang Medical School (School of Basic Medical Sciences), Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China
| | - Bi-Wen Peng
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Taikang Medical School (School of Basic Medical Sciences), Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China.
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8
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Hulme L, Hochstetler A, Schwerk C, Schroten H, Ishikawa H, Tung CY, Perrin B, Blazer-Yost B. Characterization of TRPV4-mediated signaling pathways in an optimized human choroid plexus epithelial cell line. Am J Physiol Cell Physiol 2022; 323:C1823-C1842. [PMID: 35938676 PMCID: PMC9744646 DOI: 10.1152/ajpcell.00193.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 12/14/2022]
Abstract
The objectives of these studies were twofold: 1) to characterize the human choroid plexus papilloma (HIBCPP) cell line as a model of the blood-cerebrospinal fluid barrier (BCSFB) via morphology, tightness, and polarization of transporters in choroid plexus epithelia (CPe), and 2) to utilize Ussing-style electrophysiology to elucidate signaling pathways associated with the activation of the transient receptor potential vanilloid 4 (TRPV4) channel involved in cerebrospinal fluid (CSF) secretion. RT-PCR was implemented to determine gene expression of cell fate markers, junctional complex proteins, and transporters of interest. Scanning electron microscopy and confocal three-dimensional renderings of cultures grown on permeable supports were utilized to delineate the morphology of the brush border, junctional complexes, and polarization of key transporters. Electrophysiology was used to understand and explore TRPV4-mediated signaling in the HIBCPP cell line, considering both short-circuit current (Isc) and conductance responses. HIBCPP cells grown under optimized culture conditions exhibited minimal multilayering, developed an intermediate resistance monolayer, retained differentiation properties, and expressed, and correctly localized, junctional proteins and native transporters. We found that activation of TRPV4 resulted in a robust, multiphasic change in electrogenic ion flux and increase in conductance accompanied by substantial fluid secretion. This response appears to be modulated by a number of different effectors, implicating phospholipase C (PLC), protein kinase C (PKC), and phosphoinositide 3-kinase (PI3K) in TRPV4-mediated ion flux. The HIBCPP cell line is a representative model of the human BCSFB, which can be utilized for studies of transporter function, intracellular signaling, and regulation of CSF production.
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Affiliation(s)
- Louise Hulme
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana
| | - Alexandra Hochstetler
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana
| | - Christian Schwerk
- Department of Pediatrics, Pediatric Infectious Diseases, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Horst Schroten
- Department of Pediatrics, Pediatric Infectious Diseases, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Hiroshi Ishikawa
- Department of Neurosurgery, Laboratory of Clinical Regenerative Medicine, University of Tsukuba, Ibaraki, Japan
| | - Chun-Yu Tung
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana
| | - Benjamin Perrin
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana
| | - Bonnie Blazer-Yost
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana
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9
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Blazer-Yost BL. Following Ussing's legacy: from amphibian models to mammalian kidney and brain. Am J Physiol Cell Physiol 2022; 323:C1061-C1069. [PMID: 36036449 PMCID: PMC9529261 DOI: 10.1152/ajpcell.00303.2022] [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: 07/12/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/22/2022]
Abstract
Professor Hans H. Ussing (1911-2000) was one of the founding members of the field of epithelial cell biology. He is most famous for the electrophysiological technique that he developed to measure electrogenic ion flux across epithelial tissues. Ussing-style electrophysiology has been applied to multiple tissues and has informed fields as diverse as amphibian biology and medicine. In the latter, this technique has contributed to a basic understanding of maladies such as hypertension, polycystic kidney disease, cystic fibrosis, and diarrheal diseases to mention but a few. In addition to this valuable contribution to biological methods, Prof. Ussing also provided strong evidence for the concept of active transport several years before the elucidation of Na+K+ATPase. In addition, he provided cell biologists with the important concept of polarized epithelia with specific and different transporters found in the apical and basolateral membranes, thus providing these cells with the ability to conduct directional, active and passive transepithelial transport. My studies have used Ussing chamber electrophysiology to study the toad urinary bladder, an amphibian cell line, renal cell lines, and, most recently, choroid plexus cell lines. This technique has formed the basis of our in vitro mechanistic studies that are used in an iterative manner with animal models to better understand disease progress and treatment. I was honored to be invited to deliver the 2022 Hans Ussing Lecture sponsored by the Epithelial Transport Group of the American Physiological Society. This manuscript is a version of the material presented in that lecture.
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Affiliation(s)
- Bonnie L Blazer-Yost
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana
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10
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Dabbagh F, Schroten H, Schwerk C. In Vitro Models of the Blood–Cerebrospinal Fluid Barrier and Their Applications in the Development and Research of (Neuro)Pharmaceuticals. Pharmaceutics 2022; 14:pharmaceutics14081729. [PMID: 36015358 PMCID: PMC9412499 DOI: 10.3390/pharmaceutics14081729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/11/2022] [Accepted: 08/16/2022] [Indexed: 11/30/2022] Open
Abstract
The pharmaceutical research sector has been facing the challenge of neurotherapeutics development and its inherited high-risk and high-failure-rate nature for decades. This hurdle is partly attributable to the presence of brain barriers, considered both as obstacles and opportunities for the entry of drug substances. The blood–cerebrospinal fluid (CSF) barrier (BCSFB), an under-studied brain barrier site compared to the blood–brain barrier (BBB), can be considered a potential therapeutic target to improve the delivery of CNS therapeutics and provide brain protection measures. Therefore, leveraging robust and authentic in vitro models of the BCSFB can diminish the time and effort spent on unproductive or redundant development activities by a preliminary assessment of the desired physiochemical behavior of an agent toward this barrier. To this end, the current review summarizes the efforts and progresses made to this research area with a notable focus on the attribution of these models and applied techniques to the pharmaceutical sector and the development of neuropharmacological therapeutics and diagnostics. A survey of available in vitro models, with their advantages and limitations and cell lines in hand will be provided, followed by highlighting the potential applications of such models in the (neuro)therapeutics discovery and development pipelines.
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11
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Natur S, Damri O, Agam G. The Effect of Global Warming on Complex Disorders (Mental Disorders, Primary Hypertension, and Type 2 Diabetes). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159398. [PMID: 35954764 PMCID: PMC9368177 DOI: 10.3390/ijerph19159398] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 01/09/2023]
Abstract
Multiple studies imply a strong relationship between global warming (GW) and complex disorders. This review summarizes such reports concentrating on three disorders-mental disorders (MD), primary hypertension, and type 2 diabetes (T2D). We also attempt to point at potential mechanisms mediating the effect of GW on these disorders. Concerning mental disorders, immediate candidates are brain levels of heat-shock proteins (HSPs). In addition, given that heat stress increases reactive oxygen species (ROS) levels which may lead to blood-brain barrier (BBB) breakdown and, hence, enhanced protein extravasation in the brain, this might finally cause, or exacerbate mental health. As for hypertension, since its causes are incompletely understood, the mechanism(s) by which heat exposure affects blood pressure (BP) is an open question. Since the kidneys participate in regulating blood volume and BP they are considered as a site of heat-associated disease, hence, we discuss hyperosmolarity as a potential mediator. In addition, we relate to autoimmunity, inflammation, sodium excretion, and HSP70 as risk factors that might play a role in the effect of heat on hypertension. In the case of T2D, we raise two potential mediators of the effect of exposure to ambient hot environment on the disease's incidence-brown adipose tissue metabolism and HSPs.
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12
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Ma L, Liu X, Liu Q, Jin S, Chang H, Liu H. The Roles of Transient Receptor Potential Ion Channels in Pathologies of Glaucoma. Front Physiol 2022; 13:806786. [PMID: 35185615 PMCID: PMC8850928 DOI: 10.3389/fphys.2022.806786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022] Open
Abstract
Transient receptor ion potential (TRP) channels are a cluster of non-selective cation channels present on cell membranes. They are important mediators of sensory signals to regulate cellular functions and signaling pathways. Alterations and dysfunction of these channels could disrupt physiological processes, thus leading to a broad array of disorders, such as cardiovascular, renal and nervous system diseases. These effects position them as potential targets for drug design and treatment. Because TRP channels can mediate processes such as mechanical conduction, osmotic pressure, and oxidative stress, they have been studied in the context of glaucoma. Glaucoma is an irreversible blinding eye disease caused by an intermittent or sustained increase in intraocular pressure (IOP), which results in the apoptosis of retinal ganglion cells (RGCs), optic nerve atrophy and eventually visual field defects. An increasing number of studies have documented that various TRP subfamilies are abundantly expressed in ocular structures, including the cornea, lens, ciliary body (CB), trabecular meshwork (TM) and retina. In alignment with these findings, there is also mounting evidence supporting the potential role of the TRP family in glaucoma progression. Therefore, it is of great interest and clinical significance to gain an increased understanding of these channels, which in turn could shed more light on the identification of new therapeutic targets for glaucoma. Moreover, this role is not understood completely to date, and whether the activation of TRP channels contributes to glaucoma, or instead aggravates progression, needs to be explored. In this manuscript, we aim to provide a comprehensive overview of recent research on TRP channels in glaucoma and to suggest novel targets for future therapeutic interventions in glaucoma.
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Affiliation(s)
- Lin Ma
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xin Liu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Liu
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, The Brain Cognition and Brain Disease Institute, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Sen Jin
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, The Brain Cognition and Brain Disease Institute, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Heng Chang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haixia Liu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Haixia Liu,
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13
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Bothwell SW, Omileke D, Patabendige A, Spratt NJ. CSF Secretion Is Not Altered by NKCC1 Nor TRPV4 Antagonism in Healthy Rats. Brain Sci 2021; 11:brainsci11091117. [PMID: 34573139 PMCID: PMC8471756 DOI: 10.3390/brainsci11091117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/20/2021] [Accepted: 08/22/2021] [Indexed: 11/16/2022] Open
Abstract
Background: Cerebrospinal fluid (CSF) secretion can be targeted to reduce elevated intracranial pressure (ICP). Sodium-potassium-chloride cotransporter 1 (NKCC1) antagonism is used clinically. However, supporting evidence is limited. The transient receptor potential vanilloid-4 (TRPV4) channel may also regulate CSF secretion and ICP elevation. We investigated whether antagonism of these proteins reduces CSF secretion. Methods: We quantified CSF secretion rates in male Wistar rats. The cerebral aqueduct was blocked with viscous mineral oil, and a lateral ventricle was cannulated. Secretion rate was measured at baseline and after antagonist administration. Acetazolamide was administered as a positive control to confirm changes in CSF secretion rates. Results: Neither NKCC1, nor TRPV4 antagonism altered CSF secretion rate from baseline, n = 3, t(2) = 1.14, p = 0.37, and n = 4, t(3) = 0.58, p = 0.6, respectively. Acetazolamide reduced CSF secretion by ~50% across all groups, n = 7, t(6) = 4.294, p = 0.005. Conclusions: Acute antagonism of NKCC1 and TRPV4 proteins at the choroid plexus does not reduce CSF secretion in healthy rats. Further investigation of protein changes and antagonism should be explored in neurological disease where increased CSF secretion and ICP are observed before discounting the therapeutic potential of protein antagonism at these sites.
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Affiliation(s)
- Steven W. Bothwell
- The School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW 2308, Australia; (S.W.B.); (D.O.)
- Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
| | - Daniel Omileke
- The School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW 2308, Australia; (S.W.B.); (D.O.)
- Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
| | - Adjanie Patabendige
- The School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW 2308, Australia; (S.W.B.); (D.O.)
- Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Wirral CH64 7TE, UK
- Correspondence: (A.P.); (N.J.S.)
| | - Neil J. Spratt
- The School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW 2308, Australia; (S.W.B.); (D.O.)
- Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
- Hunter New England Local Health District, New Lambton Heights, NSW 2305, Australia
- Correspondence: (A.P.); (N.J.S.)
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14
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Hochstetler AE, Smith HM, Preston DC, Reed MM, Territo PR, Shim JW, Fulkerson D, Blazer-Yost BL. TRPV4 antagonists ameliorate ventriculomegaly in a rat model of hydrocephalus. JCI Insight 2020; 5:137646. [PMID: 32938829 PMCID: PMC7526552 DOI: 10.1172/jci.insight.137646] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/19/2020] [Indexed: 11/27/2022] Open
Abstract
Hydrocephalus is a serious condition that impacts patients of all ages. The standards of care are surgical options to divert, or inhibit production of, cerebrospinal fluid; to date, there are no effective pharmaceutical treatments, to our knowledge. The causes vary widely, but one commonality of this condition is aberrations in salt and fluid balance. We have used a genetic model of hydrocephalus to show that ventriculomegaly can be alleviated by inhibition of the transient receptor potential vanilloid 4, a channel that is activated by changes in osmotic balance, temperature, pressure and inflammatory mediators. The TRPV4 antagonists do not appear to have adverse effects on the overall health of the WT or hydrocephalic animals. Two distinct TRPV4 antagonists ameliorate ventriculomegaly in a genetic rat model of severe postnatal hydrocephalus, with no apparent adverse effects on animals.
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Affiliation(s)
| | - Hillary M Smith
- Department of Biology, Indiana University, Purdue University, Indianapolis, Indiana, USA
| | - Daniel C Preston
- Department of Biology, Indiana University, Purdue University, Indianapolis, Indiana, USA
| | - Makenna M Reed
- Department of Biology, Indiana University, Purdue University, Indianapolis, Indiana, USA
| | - Paul R Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Joon W Shim
- Department of Biology, Indiana University, Purdue University, Indianapolis, Indiana, USA
| | | | - Bonnie L Blazer-Yost
- Department of Biology, Indiana University, Purdue University, Indianapolis, Indiana, USA
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15
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Rosenkranz SC, Shaposhnykov A, Schnapauff O, Epping L, Vieira V, Heidermann K, Schattling B, Tsvilovskyy V, Liedtke W, Meuth SG, Freichel M, Gelderblom M, Friese MA. TRPV4-Mediated Regulation of the Blood Brain Barrier Is Abolished During Inflammation. Front Cell Dev Biol 2020; 8:849. [PMID: 32974355 PMCID: PMC7481434 DOI: 10.3389/fcell.2020.00849] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 08/07/2020] [Indexed: 12/18/2022] Open
Abstract
Blood-brain barrier (BBB) dysfunction is critically involved in determining the extent of several central nervous systems (CNS) pathologies and here in particular neuroinflammatory conditions. Inhibiting BBB breakdown could reduce the level of vasogenic edema and the number of immune cells invading the CNS, thereby counteracting neuronal injury. Transient receptor potential (TRP) channels have an important role as environmental sensors and constitute attractive therapeutic targets that are involved in calcium homeostasis during pathologies of the CNS. Transient receptor potential vanilloid 4 (TRPV4) is a calcium permeable, non-selective cation channel highly expressed in endothelial cells. As it is involved in the regulation of the blood brain barrier permeability and consequently cerebral edema formation, we anticipated a regulatory role of TRPV4 in CNS inflammation and subsequent neuronal damage. Here, we detected an increase in transendothelial resistance in mouse brain microvascular endothelial cells (MbMECs) after treatment with a selective TRPV4 inhibitor. However, this effect was abolished after the addition of IFNγ and TNFα indicating that inflammatory conditions override TRPV4-mediated permeability. Accordingly, we did not observe a protection of Trpv4-deficient mice when compared to wildtype controls in a preclinical model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), and no differences in infarct sizes following transient middle cerebral artery occlusion (tMCAO), the experimental stroke model, which leads to an acute postischemic inflammatory response. Furthermore, Evans Blue injections did not show differences in alterations of the blood brain barrier (BBB) permeability between genotypes in both animal models. Together, TRPV4 does not regulate brain microvascular endothelial permeability under inflammation.
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Affiliation(s)
- Sina C Rosenkranz
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Artem Shaposhnykov
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Schnapauff
- Klinik und Poliklinik für Neurologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Lisa Epping
- Klinik für Neurologie mit Institut für Translationale Neurologie, Universität Münster, Münster, Germany
| | - Vanessa Vieira
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Karsten Heidermann
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Benjamin Schattling
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | | | - Wolfgang Liedtke
- Departments of Neurology, Anesthesiology and Neurobiology, Duke University Medical Center, Durham, NC, United States
| | - Sven G Meuth
- Klinik für Neurologie mit Institut für Translationale Neurologie, Universität Münster, Münster, Germany
| | - Marc Freichel
- Pharmakologisches Institut, Universität Heidelberg, Heidelberg, Germany
| | - Mathias Gelderblom
- Klinik und Poliklinik für Neurologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Manuel A Friese
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
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16
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Ma X, Liu W. Calcium signaling in brain microvascular endothelial cells and its roles in the function of the blood-brain barrier. Neuroreport 2020; 30:1271-1277. [PMID: 31688421 DOI: 10.1097/wnr.0000000000001357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The blood-brain barrier (BBB) plays critical roles in maintaining the stability of the brain's internal milieu, providing nutrients for the brain, and preventing toxic materials from the blood from entering the brain. The cellular structure of the BBB is mainly composed of brain microvascular endothelial cells (BMVECs), which are surrounded by astrocytic endfeet that are connected by tight junction proteins, pericytes and astrocytes. Recently, several studies have shown that aberrant increase in intracellular calcium levels in BMVECs lead to cellular metabolic disturbances and subsequent impairment of BBB integrity. Although multiple stresses can lead to intracellular calcium accumulation, inherent protective mechanisms in affected cells are subsequently activated to maintain calcium homeostasis. However, once the increase in intracellular calcium goes beyond a certain threshold, disturbances in cellular structures, protein expression, and the BBB permeability are inevitable. Here, we review recent research on the different factors regulating intracellular calcium concentrations and the mechanisms related to how calcium signaling cascades protect the BMVECs from outside injury. We also consider the potential of calcium signaling regulators as therapeutic targets for modulating intracellular calcium homeostasis and ameliorating BBB disruption in patients with calcium-related pathologies.
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Affiliation(s)
- Xingjie Ma
- Department of Intensive Care, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
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17
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TRPV4 promotes acoustic wave-mediated BBB opening via Ca 2+/PKC-δ pathway. J Adv Res 2020; 26:15-28. [PMID: 33133680 PMCID: PMC7584681 DOI: 10.1016/j.jare.2020.06.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 05/14/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023] Open
Abstract
Introduction Numerous studies have shown the ability of low-energy acoustic waves such as focused ultrasound or shockwave to transiently open blood-brain barrier (BBB) and facilitate drug delivery to the brain. Preclinical and clinical evidences have well demonstrated the efficacy and safety in treating various brain disorders. However, the molecular mechanisms of acoustic waves on the BBB are still not fully understood. Objectives The present study aimed at exploring the possible molecular mechanisms of acoustic wave stimulation on brains. Methods: Briefly describe the experimental design The left hemisphere of the rat‘s brain was treated with pulsed ultrasound from a commercial focused shockwave or a planar ultrasound device, and the right hemisphere served as a control. One hour after the mechanical wave stimulation or overnight, the rats were sacrificed and the brains were harvested for protein or histological analysis. Agonists and antagonists related to the signal transduction pathways of tight junction proteins were used to investigate the possible intracellular mechanisms. Results Intracellular signal transduction analysis shows calcium influx through transient receptor potential vanilloid 4 (TRPV4) channels, and the activation of PKC-δ pathway to mediate dissociation of ZO-1 and occludin after acoustic wave stimulation. The activation of TRPV4 or PKC-δ signaling further increased the expression level of TRPV4, suggesting a feedback loop to regulate BBB permeability. Moreover, the tight junction proteins dissociation can be reversed by administration of PKC-δ inhibitor and TRPV4 antagonist. Conclusion The present study shows the crucial role of TRPV4 in acoustic wave-mediated BBB permeability, specifically its effect on compromising tight junction proteins, ZO-1 and occludin. Our findings provide a new molecular perspective to explain acoustic wave-mediated BBB opening. Moreover, activation of TRPV4 by agonists may reduce the threshold intensity level of acoustic waves for BBB opening, which may prevent undesirable mechanical damages while maintaining efficient BBB opening.
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18
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Michalick L, Kuebler WM. TRPV4-A Missing Link Between Mechanosensation and Immunity. Front Immunol 2020; 11:413. [PMID: 32210976 PMCID: PMC7076180 DOI: 10.3389/fimmu.2020.00413] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 02/21/2020] [Indexed: 12/21/2022] Open
Abstract
Transient receptor potential vanilloid-type 4 (TRPV4) cation channel is widely expressed in all tissues as well as in immune cells and its function as mechanosensitive Ca2+ channel seems to be conserved throughout all mammalian species. Of late, emerging evidence has implicated TRPV4 in the activation and differentiation of innate immune cells, especially in neutrophils, monocytes, and macrophages. As such, TRPV4 has been shown to mediate neutrophil adhesion and chemotaxis, as well as production of reactive oxygen species in response to pro-inflammatory stimuli. In macrophages, TRPV4 mediates formation of both reactive oxygen and nitrogen species, and regulates phagocytosis, thus facilitating bacterial clearance and resolution of infection. Importantly, TRPV4 may present a missing link between mechanical forces and immune responses. This connection has been exemplary highlighted by the demonstrated role of TRPV4 in macrophage activation and subsequent induction of lung injury following mechanical overventilation. Mechanosensation via TRPV4 is also expected to activate innate immune cells and establish a pro-inflammatory loop in fibrotic diseases with increased deposition of extracellular matrix (ECM) and substrate stiffness. Likewise, TRPV4 may be activated by cell migration through the endothelium or the extracellular matrix, or even by circulating immune cells squeezing through the narrow passages of the pulmonary or systemic capillary bed, a process that has recently been linked to neutrophil priming and depriming. Here, we provide an overview over the emerging role of TRPV4 in innate immune responses and highlight two distinct modes for the activation of TRPV4 by either mechanical forces ("mechanoTRPV4") or by pathogens ("immunoTRPV4").
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Affiliation(s)
- Laura Michalick
- Institute of Physiology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Physiology, Berlin Institute of Health, Berlin, Germany
| | - Wolfgang M. Kuebler
- Institute of Physiology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Physiology, Berlin Institute of Health, Berlin, Germany
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19
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Kumar H, Lim CS, Choi H, Joshi HP, Kim KT, Kim YH, Park CK, Kim HM, Han IB. Elevated TRPV4 Levels Contribute to Endothelial Damage and Scarring in Experimental Spinal Cord Injury. J Neurosci 2020; 40:1943-1955. [PMID: 31974206 PMCID: PMC7046444 DOI: 10.1523/jneurosci.2035-19.2020] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 12/10/2019] [Accepted: 01/04/2020] [Indexed: 11/21/2022] Open
Abstract
Currently, the role of transient receptor potential vanilloid type 4 (TRPV4), a nonselective cation channel in the pathology of spinal cord injury (SCI), is not recognized. Herein, we report the expression and contribution of TRPV4 in the pathology of scarring and endothelial and secondary damage after SCI. TRPV4 expression increased during the inflammatory phase in female rats after SCI and was expressed primarily by cells at endothelial-microglial junctions. Two-photon microscopy of intracellular-free Ca2+ levels revealed a biphasic increase at similar time points after SCI. Expression of TRPV4 at the injury epicenter, but not intracellular-free Ca2+, progressively increases with the severity of the injury. Activation of TRPV4 with specific agonist altered the organization of endothelial cells, affected tight junctions in the hCMEC/D3 BBB cell line in vitro, and increases the scarring in rat spinal cord as well as induced endothelial damage. By contrast, suppression of TRPV4 with a specific antagonist or in female Trpv4 KO mouse attenuated inflammatory cytokines and chemokines, prevented the degradation of tight junction proteins, and preserve blood-spinal cord barrier integrity, thereby attenuate the scarring after SCI. Likewise, secondary damage was reduced, and behavioral outcomes were improved in Trpv4 KO mice after SCI. These results suggest that increased TRPV4 expression disrupts endothelial cell organization during the early inflammatory phase of SCI, resulting in tissue damage, vascular destabilization, blood-spinal cord barrier breakdown, and scarring. Thus, TRPV4 inhibition/knockdown represents a promising therapeutic strategy to stabilize/protect endothelial cells, attenuate nociception and secondary damage, and reduce scarring after SCI.SIGNIFICANCE STATEMENT TRPV4, a calcium-permeable nonselective cation channel, is widely expressed in both excitable and nonexcitable cells. Spinal cord injury (SCI) majorly caused by trauma/accidents is associated with changes in osmolarity, mechanical injury, and shear stress. After SCI, TRPV4 was increased and were found to be linked with the severity of injury at the epicenter at the time points that were reported to be critical for repair/treatment. Activation of TRPV4 was damaging to endothelial cells that form the blood-spinal cord barrier and thus contributes to scarring (glial and fibrotic). Importantly, inhibition/knockdown of TRPV4 prevented these effects. Thus, the manipulation of TRPV4 signaling might lead to new therapeutic strategies or combinatorial therapies to protect endothelial cells and enhance repair after SCI.
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Affiliation(s)
- Hemant Kumar
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488
| | - Chang Su Lim
- Department of Energy System Research and Department of Chemistry, Ajou University, Suwon, Gyeonggi-do, Republic of Korea, 16499
| | - Hyemin Choi
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488
| | - Hari Prasad Joshi
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488
| | - Kyoung-Tae Kim
- Department of Neurosurgery, School of Medicine, Kyungpook National University, Daegu, Republic of Korea, 41944
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Republic of Korea, 41944, and
| | - Yong Ho Kim
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon, Republic of Korea, 13120
| | - Chul-Kyu Park
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon, Republic of Korea, 13120
| | - Hwan Myung Kim
- Department of Energy System Research and Department of Chemistry, Ajou University, Suwon, Gyeonggi-do, Republic of Korea, 16499
| | - In-Bo Han
- Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, Republic of Korea, 13488,
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20
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TRPV4 activation by thermal and mechanical stimuli in disease progression. J Transl Med 2020; 100:218-223. [PMID: 31896814 DOI: 10.1038/s41374-019-0362-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/04/2019] [Accepted: 12/15/2019] [Indexed: 12/17/2022] Open
Abstract
Body temperature is an important determinant in regulating the activities of animals. In humans, a mild 0.5 °C hyperthermia can cause headaches, demonstrating that the maintenance of normal body temperature is a key for our health. In a more extreme example, accidental acute hypothermia can lead to severe shivering, loss of consciousness, or death, although the details of these mechanisms are poorly understood. We previously found that the TRPV4 ion channel is constitutively activated by normal body temperature. The activation threshold of TRPV4 is >34 °C in the brain, which enables TRPV4 to convert thermal information into cellular signaling. Here we review the data which describe how the deletion of TRPV4 evokes abnormal behavior in mice. These studies demonstrate that the maintenance of body temperature and the sensory system for detecting body temperature, such as via TRPV4, are critical components for normal cellular function. Moreover, abnormal TRPV4 activation exacerbates cell death, epilepsy, stroke, brain edema, or cardiac fibroblast activity. In this review, we also summarize the findings related to TRPV4 and disease.
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21
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TRPV4 channels stimulate Ca 2+-induced Ca 2+ release in mouse neurons and trigger endoplasmic reticulum stress after intracerebral hemorrhage. Brain Res Bull 2018; 146:143-152. [PMID: 30508606 DOI: 10.1016/j.brainresbull.2018.11.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 10/24/2018] [Accepted: 11/29/2018] [Indexed: 01/30/2023]
Abstract
Individuals with intracerebral hemorrhage (ICH) suffer varying degrees of neurological dysfunction as a result of neuronal apoptosis, and thus, maintenance of neuronal survival may be crucial to prevent ICH brain injury. Here, we report that the expression of transient receptor potential vanilloid 4 (TRPV4) was upregulated in mouse neurons after ICH. The selective TRPV4 agonist GSK1016790 A aggravated neuronal death whereas the TRPV4 antagonist HC-067047 promoted neuronal survival after ICH. We found that GSK1016790 A triggered Ca2+ signals that were amplified and propagated by Ca2+-induced Ca2+ release (CICR) from the endoplasmic reticulum (ER) in the neurons. ICH recruited inositol triphosphate receptors (IP3Rs) into the TRPV4 protein complex, which positively regulated the activity of TRPV4 channels. Excessive activation of TRPV4 channels destroyed Ca2+ homeostasis and induced ER unfolded protein response (UPR). Blocking TRPV4 receptors decreased UPR, inhibited the PERK-CHOP-Bcl-2 signaling pathway and increased neuron survival. Overall, these results suggested that overactivation of TRPV4 channels after ICH ledto the destruction of Ca2+ homeostasis, which in turn caused UPR and neural apoptosis. Inhibition of TRPV4 channels is a promising therapy to promote neurons recover, and to ameliorate disability after ICH.
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22
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CFAP70 Is a Novel Axoneme-Binding Protein That Localizes at the Base of the Outer Dynein Arm and Regulates Ciliary Motility. Cells 2018; 7:cells7090124. [PMID: 30158508 PMCID: PMC6162463 DOI: 10.3390/cells7090124] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 08/24/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022] Open
Abstract
In the present study, we characterized CFAP70, a candidate of cilia-related protein in mice. As this protein has a cluster of tetratricopeptide repeat (TPR) domains like many components of the intraflagellar transport (IFT) complex, we investigated the domain functions of particular interest in ciliary targeting and/or localization. RT-PCR and immunohistochemistry of various mouse tissues demonstrated the association of CFAP70 with motile cilia and flagella. A stepwise extraction of proteins from swine tracheal cilia showed that CFAP70 bound tightly to the ciliary axoneme. Fluorescence microscopy of the cultured ependyma expressing fragments of CFAP70 demonstrated that the N-terminus rather than the C-terminus with the TPR domains was more important for the ciliary localization. When CFAP70 was knocked down in cultured mouse ependyma, reductions in cilia beating frequency were observed. Consistent with these observations, a Chlamydomonas mutant lacking the CFAP70 homolog, FAP70, showed defects in outer dynein arm (ODA) activity and a reduction in flagellar motility. Cryo-electron tomography revealed that the N-terminus of FAP70 resided stably at the base of the ODA. These results demonstrated that CFAP70 is a novel regulatory component of the ODA in motile cilia and flagella, and that the N-terminus is important for its ciliary localization.
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23
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Preston D, Simpson S, Halm D, Hochstetler A, Schwerk C, Schroten H, Blazer-Yost BL. Activation of TRPV4 stimulates transepithelial ion flux in a porcine choroid plexus cell line. Am J Physiol Cell Physiol 2018; 315:C357-C366. [PMID: 29791207 DOI: 10.1152/ajpcell.00312.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The choroid plexus (CP) epithelium plays a major role in the production of cerebrospinal fluid (CSF). A polarized cell line, the porcine CP-Riems (PCP-R) line, which exhibits many of the characteristics of the native epithelium, was used to study the effect of activation of the transient receptor potential vanilloid 4 (TRPV4) cation channel found in the PCP-R cells as well as in the native epithelium. Ussing-style electrophysiological experiments showed that activation of TRPV4 with a specific agonist, GSK1016790A, resulted in an immediate increase in both transepithelial ion flux and conductance. These changes were inhibited by either of two distinct antagonists, HC067047 or RN1734. The change in conductance was reversible and did not involve disruption of epithelial junctional complexes. Activation of TRPV4 results in Ca2+ influx, therefore, we examined whether the electrophysiological changes were the result of secondary activation of Ca2+-sensitive channels. PCP-R cells contain two Ca2+-activated K+ channels, the small conductance 2 (SK2) and the intermediate conductance (IK) channels. Based on inhibitor studies, the former is not involved in the TRPV4-mediated electrophysiological changes whereas one of the three isoforms of the IK channel (KCNN4c) may play a role in the apical secretion of K+. Blocking the activity of this IK isoform with TRAM34 inhibited the TRPV4-mediated change in net transepithelial ion flux and the increased conductance. These studies implicate TRPV4 as a hub protein in the control of CSF production through stimulation by multiple effectors resulting in transepithelial ion and subsequent water movement.
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Affiliation(s)
- Daniel Preston
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
| | - Stefanie Simpson
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
| | - Dan Halm
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University , Dayton, Ohio
| | - Alexandra Hochstetler
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
| | - Christian Schwerk
- Mannheim Medical Faculty, University of Heidelberg, Children's Hospital , Mannheim , Germany
| | - Horst Schroten
- Mannheim Medical Faculty, University of Heidelberg, Children's Hospital , Mannheim , Germany
| | - Bonnie L Blazer-Yost
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana
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24
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Choi G, Yang TJ, Yoo S, Choi SI, Lim JY, Cho PS, Hwang SW. TRPV4-Mediated Anti-nociceptive Effect of Suberanilohydroxamic Acid on Mechanical Pain. Mol Neurobiol 2018; 56:444-453. [PMID: 29707744 DOI: 10.1007/s12035-018-1093-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/19/2018] [Indexed: 11/29/2022]
Abstract
Biological effects of suberanilohydroxamic acid (SAHA) have mainly been observed in the context of tumor suppression via epigenetic mechanisms, but other potential outcomes from its use have also been proposed in different fields such as pain modulation. Here, we tried to understand whether SAHA modulates specific pain modalities by a non-epigenetic unknown mechanism. From 24 h Complete Freund's Adjuvant (CFA)-inflamed hind paws of mice, mechanical and thermal inflammatory pain indices were collected with or without immediate intraplantar injection of SAHA. To examine the action of SAHA on sensory receptor-specific pain, transient receptor potential (TRP) ion channel-mediated pain indices were collected in the same manner of intraplantar treatment. Activities of primarily cultured sensory neurons and heterologous cells transfected with TRP channels were monitored to determine the molecular mechanism underlying the pain-modulating effect of SAHA. As a result, immediate and localized pretreatment with SAHA, avoiding an epigenetic intervention, acutely attenuated mechanical inflammatory pain and receptor-specific pain evoked by injection of a TRP channel agonist in animal models. We show that a component of the mechanisms involves TRPV4 inhibition based on in vitro intracellular Ca2+ imaging and electrophysiological assessments with heterologous expression systems and cultured sensory neurons. Taken together, the present study provides evidence of a novel off-target action and its mechanism of SAHA in its modality-specific anti-nociceptive effect and suggests the utility of this compound for pharmacological modulation of pain.
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Affiliation(s)
- Geunyeol Choi
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, South Korea
| | - Tae-Jin Yang
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, South Korea
| | - Sungjae Yoo
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, South Korea
| | - Seung-In Choi
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, South Korea
| | - Ji Yeon Lim
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, South Korea
| | - Pyung Sun Cho
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, South Korea
| | - Sun Wook Hwang
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, South Korea. .,Department of Physiology, Korea University College of Medicine, Seoul, 02841, South Korea.
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Zhao H, Zhang K, Tang R, Meng H, Zou Y, Wu P, Hu R, Liu X, Feng H, Chen Y. TRPV4 Blockade Preserves the Blood-Brain Barrier by Inhibiting Stress Fiber Formation in a Rat Model of Intracerebral Hemorrhage. Front Mol Neurosci 2018; 11:97. [PMID: 29636662 PMCID: PMC5880899 DOI: 10.3389/fnmol.2018.00097] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 03/12/2018] [Indexed: 12/25/2022] Open
Abstract
Blood–brain barrier (BBB) disruption and subsequent brain edema play important roles in the secondary neuronal death and neurological dysfunction that are observed following intracerebral hemorrhage (ICH). In previous studies, transient receptor potential vanilloid 4 (TRPV4), a calcium-permeable mechanosensitive channel, was shown to induce cytotoxicity in many types of cells and to play a role in orchestrating barrier functions. In the present study, we explored the role of TRPV4 in ICH-induced brain injury, specifically investigating its effect on BBB disruption. Autologous arterial blood was injected into the basal ganglia of rats to mimic ICH. Adult male Sprague Dawley rats were randomly assigned to sham and experimental groups for studies on the time course of TRPV4 expression after ICH. The selective TRPV4 antagonist HC-067047 and TRPV4 siRNA were administered to evaluate the effects of TRPV4 inhibition. GSK1016790A, a TRPV4 agonist, was administered to naive rats to verify the involvement of TRPV4-induced BBB disruption. A PKC inhibitor, dihydrochloride (H7), and a selective RhoA inhibitor, C3 transferase, were administered to clarify the involvement of the PKCα/RhoA/MLC2 pathway following ICH. Post-ICH assessments including functional tests, brain edema measurements, Evans blue extravasation, western blotting and immunohistochemical assays were performed. TRPV4 inhibition remarkably ameliorated neurological symptoms, brain edema, and neuronal death, as well as BBB disruption, 24–72 h following ICH. Meanwhile, TRPV4 blockade preserved the expression of adherens and tight junction proteins, as well as BBB integrity, by inhibiting stress fiber formation, which might be correlated with the regulation of components of the PKCα/RhoA/MLC2 pathway. Furthermore, adherens and tight junction protein degradation induced by GSK1016790A treatment in naive rats was also related to PKCα/RhoA/MLC2-pathway-mediated stress fiber formation. Based on these findings, therapeutic interventions targeting TRPV4 may represent a novel approach to ameliorate secondary brain injury following ICH.
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Affiliation(s)
- Hengli Zhao
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Kaiyuan Zhang
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Rongrui Tang
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Hui Meng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yongjie Zou
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Pengfei Wu
- Department of Neurosurgery, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Rong Hu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Xin Liu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yujie Chen
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
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26
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Kumar H, Lee SH, Kim KT, Zeng X, Han I. TRPV4: a Sensor for Homeostasis and Pathological Events in the CNS. Mol Neurobiol 2018; 55:8695-8708. [PMID: 29582401 DOI: 10.1007/s12035-018-0998-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 03/07/2018] [Indexed: 01/22/2023]
Abstract
Transient receptor potential vanilloid type 4 (TRPV4) was originally described as a calcium-permeable nonselective cation channel. TRPV4 is now recognized as a polymodal ionotropic receptor: it is a broadly expressed, nonselective cation channel (permeable to calcium, potassium, magnesium, and sodium) that plays an important role in a multitude of physiological processes. TRPV4 is involved in maintaining homeostasis, serves as an osmosensor and thermosensor, can be activated directly by endogenous or exogenous chemical stimuli, and can be activated or sensitized indirectly via intracellular signaling pathways. Additionally, TRPV4 is upregulated in a variety of pathological conditions. In this review, we focus on the role of TRPV4 in mediating homeostasis and pathological events in the central nervous system (CNS). This review is composed of three parts. Section 1 describes the role of TRPV4 in maintaining homeostatic processes, including the volume of body water, ionic concentrations, volume, and the temperature. Section 2 describes the effects of activation and inhibition of TRPV4 in the CNS. Section 3 focuses on the role of TRPV4 during pathological events in CNS.
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Affiliation(s)
- Hemant Kumar
- Department of Neurosurgery, CHA University, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, 13496, Republic of Korea
| | - Soo-Hong Lee
- Department of Biomedical Science, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Kyoung-Tae Kim
- Department of Neurosurgery, Kyungpook National University Hospital, 130, Dongdeok-ro, Jung-gu, Daegu, 41944, Republic of Korea
| | - Xiang Zeng
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China.
| | - Inbo Han
- Department of Neurosurgery, CHA University, CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do, 13496, Republic of Korea.
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27
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Ishii T, Uchida K, Hata S, Hatta M, Kita T, Miyake Y, Okamura K, Tamaoki S, Ishikawa H, Yamazaki J. TRPV2 channel inhibitors attenuate fibroblast differentiation and contraction mediated by keratinocyte-derived TGF-β1 in an in vitro wound healing model of rats. J Dermatol Sci 2018; 90:332-342. [PMID: 29610016 DOI: 10.1016/j.jdermsci.2018.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND Keratinocytes release several factors that are involved in wound contracture and scar formation. We previously reported that a three-dimensional reconstruction model derived from rat skin represents a good wound healing model. OBJECTIVE We characterized the role of transient receptor potential (TRP) channels in the release of transforming growth factor (TGF)-β1 from keratinocytes and the differentiation of fibroblasts to identify possible promising pharmacological approaches to prevent scar formation and contractures. METHODS The three-dimensional culture model was made from rat keratinocytes seeded on a collagen gel in which dermal fibroblasts had been embedded. RESULTS Among the TRP channel inhibitors tested, the TRPV2 inhibitors SKF96365 and tranilast attenuated most potently keratinocyte-dependent and - independent collagen gel contraction due to TGF-β signaling as well as TGF-β1 release from keratinocytes and α-smooth muscle actin production in myofibroblasts. Besides the low amounts detected in normal dermis, TRPV2 mRNA and protein levels were increased after fibroblasts were embedded in the gel. TRPV2 was also expressed in the epidermis and keratinocyte layers of the model. Both inhibitors and TRPV2 siRNA attenuated the intracellular increase of Ca2+ induced by the TRPV agonist 2-aminoethoxydiphenyl borate in TGF-β1-pretreated fibroblasts. CONCLUSION This is the first study to show that compounds targeting TRPV2 channels ameliorate wound contraction through the inhibition of TGF-β1 release and the differentiation of dermal fibroblasts in a culture model.
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Affiliation(s)
- Taro Ishii
- Department of Oral Growth & Development, Fukuoka 814-0193, Japan
| | - Kunitoshi Uchida
- Department of Physiological Science & Molecular Biology, Fukuoka 814-0193, Japan
| | - Shozaburo Hata
- Department of Oral Growth & Development, Fukuoka 814-0193, Japan
| | - Mitsutoki Hatta
- Department of Physiological Science & Molecular Biology, Fukuoka 814-0193, Japan
| | - Tomo Kita
- Department of Physiological Science & Molecular Biology, Fukuoka 814-0193, Japan
| | - Yuki Miyake
- Department of Oral Growth & Development, Fukuoka 814-0193, Japan
| | - Kazuhiko Okamura
- Department of Morphological Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan
| | - Sachio Tamaoki
- Department of Oral Growth & Development, Fukuoka 814-0193, Japan
| | | | - Jun Yamazaki
- Department of Physiological Science & Molecular Biology, Fukuoka 814-0193, Japan.
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28
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Phuong TTT, Redmon SN, Yarishkin O, Winter JM, Li DY, Križaj D. Calcium influx through TRPV4 channels modulates the adherens contacts between retinal microvascular endothelial cells. J Physiol 2017; 595:6869-6885. [PMID: 28949006 DOI: 10.1113/jp275052] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/18/2017] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS Endothelial cells employ transient receptor potential isoform 4 (TRPV4) channels to sense ambient mechanical and chemical stimuli. In retinal microvascular endothelial cells, TRPV4 channels regulate calcium homeostasis, cytoskeletal signalling and the organization of adherens junctional contacts. Intracellular calcium increases induced by TRPV4 agonists include a significant contribution from calcium release from internal stores. Activation of TRPV4 channels regulates retinal endothelial barriers in vitro and in vivo. TRPV4 sensing may provide a feedback mechanism between sensing shear flow and eicosanoid modulators, vascular permeability and contractility at the inner retinal endothelial barrier. ABSTRACT The identity of microvascular endothelial (MVE) mechanosensors that sense blood flow in response to mechanical and chemical stimuli and regulate vascular permeability in the retina is unknown. Using immunohistochemistry, calcium imaging, electrophysiology, impedance measurements and vascular permeability assays, we show that the transient receptor potential isoform 4 (TRPV4) plays a major role in Ca2+ /cation signalling, cytoskeletal remodelling and barrier function in retinal microvasculature in vitro and in vivo. Human retinal MVE cells (HrMVECs) predominantly expressed Trpv1 and Trpv4 transcripts, and TRPV4 was broadly localized to the plasma membrane of cultured cells and intact blood vessels in the inner retina. Treatment with the selective TRPV4 agonist GSK1016790A (GSK101) activated a nonselective cation current, robustly elevated [Ca2+ ]i and reversibly increased the permeability of MVEC monolayers. This was associated with disrupted organization of endothelial F-actin, downregulated expression of occludin and remodelling of adherens contacts consisting of vascular endothelial cadherin (VE-cadherin) and β-catenin. In vivo, GSK101 increased the permeability of retinal blood vessels in wild type but not in TRPV4 knockout mice. Agonist-evoked effects on barrier permeability and cytoskeletal reorganization were antagonized by the selective TRPV4 blocker HC 067047. Human choroidal endothelial cells expressed lower TRPV4 mRNA/protein levels and showed less pronounced agonist-evoked calcium signals compared to MVECs. These findings indicate a major role for TRPV4 in Ca2+ homeostasis and barrier function in human retinal capillaries and suggest that TRPV4 may differentially contribute to the inner vs. outer blood-retinal barrier function.
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Affiliation(s)
- Tam T T Phuong
- Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Sarah N Redmon
- Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Oleg Yarishkin
- Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jacob M Winter
- Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Dean Y Li
- Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA.,Department of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, UT, USA.,Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, UT, USA
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29
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Transient Receptor Potential Vanilloid 4 and Serum Glucocorticoid-regulated Kinase 1 Are Critical Mediators of Lung Injury in Overventilated Mice In Vivo. Anesthesiology 2017; 126:300-311. [PMID: 27861175 DOI: 10.1097/aln.0000000000001443] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mechanical ventilation can cause lung endothelial barrier failure and inflammation cumulating in ventilator-induced lung injury. Yet, underlying mechanotransduction mechanisms remain unclear. Here, the authors tested the hypothesis that activation of the mechanosensitive Ca channel transient receptor potential vanilloid (TRPV4) by serum glucocorticoid-regulated kinase (SGK) 1 may drive the development of ventilator-induced lung injury. METHODS Mice (total n = 54) were ventilated for 2 h with low (7 ml/kg) or high (20 ml/kg) tidal volumes and assessed for signs of ventilator-induced lung injury. Isolated-perfused lungs were inflated with continuous positive airway pressures of 5 or 15 cm H2O (n = 7 each), and endothelial calcium concentration was quantified by real-time imaging. RESULTS Genetic deficiency or pharmacologic inhibition of TRPV4 or SGK1 protected mice from overventilation-induced vascular leakage (reduction in alveolar protein concentration from 0.84 ± 0.18 [mean ± SD] to 0.46 ± 0.16 mg/ml by TRPV4 antagonization), reduced lung inflammation (macrophage inflammatory protein 2 levels of 193 ± 163 in Trpv4 vs. 544 ± 358 pmol/ml in wild-type mice), and attenuated endothelial calcium responses to lung overdistension. Functional coupling of TRPV4 and SGK1 in lung endothelial mechanotransduction was confirmed by proximity ligation assay demonstrating enhanced TRPV4 phosphorylation at serine 824 at 18% as compared to 5% cyclic stretch, which was prevented by SGK1 inhibition. CONCLUSIONS Lung overventilation promotes endothelial calcium influx and barrier failure through a mechanism that involves activation of TRPV4, presumably due to phosphorylation at its serine 824 residue by SGK1. TRPV4 and SGK1 may present promising new targets for prevention or treatment of ventilator-induced lung injury.
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30
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Disrupting sensitization of TRPV4. Neuroscience 2017; 352:1-8. [DOI: 10.1016/j.neuroscience.2017.03.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/23/2017] [Accepted: 03/23/2017] [Indexed: 12/29/2022]
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31
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Ryskamp DA, Frye AM, Phuong TTT, Yarishkin O, Jo AO, Xu Y, Lakk M, Iuso A, Redmon SN, Ambati B, Hageman G, Prestwich GD, Torrejon KY, Križaj D. TRPV4 regulates calcium homeostasis, cytoskeletal remodeling, conventional outflow and intraocular pressure in the mammalian eye. Sci Rep 2016; 6:30583. [PMID: 27510430 PMCID: PMC4980693 DOI: 10.1038/srep30583] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/04/2016] [Indexed: 01/20/2023] Open
Abstract
An intractable challenge in glaucoma treatment has been to identify druggable targets within the conventional aqueous humor outflow pathway, which is thought to be regulated/dysregulated by elusive mechanosensitive protein(s). Here, biochemical and functional analyses localized the putative mechanosensitive cation channel TRPV4 to the plasma membrane of primary and immortalized human TM (hTM) cells, and to human and mouse TM tissue. Selective TRPV4 agonists and substrate stretch evoked TRPV4-dependent cation/Ca2+ influx, thickening of F-actin stress fibers and reinforcement of focal adhesion contacts. TRPV4 inhibition enhanced the outflow facility and lowered perfusate pressure in biomimetic TM scaffolds populated with primary hTM cells. Systemic delivery, intraocular injection or topical application of putative TRPV4 antagonist prodrug analogs lowered IOP in glaucomatous mouse eyes and protected retinal neurons from IOP-induced death. Together, these findings indicate that TRPV4 channels function as a critical component of mechanosensitive, Ca2+-signaling machinery within the TM, and that TRPV4-dependent cytoskeletal remodeling regulates TM stiffness and outflow. Thus, TRPV4 is a potential IOP sensor within the conventional outflow pathway and a novel target for treating ocular hypertension.
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Affiliation(s)
- Daniel A Ryskamp
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Interdepartmental Program in Neuroscience, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Amber M Frye
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Tam T T Phuong
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Oleg Yarishkin
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Andrew O Jo
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Yong Xu
- Department of Medicinal Chemistry, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Monika Lakk
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Interdepartmental Program in Neuroscience, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Anthony Iuso
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Interdepartmental Program in Neuroscience, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Sarah N Redmon
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Interdepartmental Program in Neuroscience, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Balamurali Ambati
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Gregory Hageman
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Center for Translational Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Glenn D Prestwich
- Department of Medicinal Chemistry, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | | | - David Križaj
- Department of Ophthalmology &Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Interdepartmental Program in Neuroscience, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Center for Translational Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Department of Neurobiology &Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.,Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA
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Abstract
This review provides a summary of the physiological significance of the TRPV4 ion channel. Although TRPV4 was initially characterized as an osmosensor, we found that TRPV4 can also act as a thermosensor or a mechanosensor in brain neurons or epithelial cells in the urinary bladder. Here, we summarize the newly characterized functions of TRPV4, including the research progress that has been made toward our understanding of TRPV4 physiology, and discuss other recent data pertaining to TRPV4. It is thought that TRPV4 may be an important drug target based on its broad expression patterns and important physiological functions. Possible associations between diseases and TRPV4 are also discussed.
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Affiliation(s)
- Koji Shibasaki
- Department of Molecular and Cellular Neurobiology, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan.
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33
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Differential volume regulation and calcium signaling in two ciliary body cell types is subserved by TRPV4 channels. Proc Natl Acad Sci U S A 2016; 113:3885-90. [PMID: 27006502 DOI: 10.1073/pnas.1515895113] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Fluid secretion by the ciliary body plays a critical and irreplaceable function in vertebrate vision by providing nutritive support to the cornea and lens, and by maintaining intraocular pressure. Here, we identify TRPV4 (transient receptor potential vanilloid isoform 4) channels as key osmosensors in nonpigmented epithelial (NPE) cells of the mouse ciliary body. Hypotonic swelling and the selective agonist GSK1016790A (EC50 ∼33 nM) induced sustained transmembrane cation currents and cytosolic [Formula: see text] elevations in dissociated and intact NPE cells. Swelling had no effect on [Formula: see text] levels in pigment epithelial (PE) cells, whereas depolarization evoked [Formula: see text] elevations in both NPE and PE cells. Swelling-evoked [Formula: see text] signals were inhibited by the TRPV4 antagonist HC067047 (IC50 ∼0.9 μM) and were absent in Trpv4(-/-) NPE. In NPE, but not PE, swelling-induced [Formula: see text] signals required phospholipase A2 activation. TRPV4 localization to NPE was confirmed with immunolocalization and excitation mapping approaches, whereas in vivo MRI analysis confirmed TRPV4-mediated signals in the intact mouse ciliary body. Trpv2 and Trpv4 were the most abundant vanilloid transcripts in CB. Overall, our results support a model whereby TRPV4 differentially regulates cell volume, lipid, and calcium signals in NPE and PE cell types and therefore represents a potential target for antiglaucoma medications.
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34
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Del Bigio MR, Di Curzio DL. Nonsurgical therapy for hydrocephalus: a comprehensive and critical review. Fluids Barriers CNS 2016; 13:3. [PMID: 26846184 PMCID: PMC4743412 DOI: 10.1186/s12987-016-0025-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/15/2016] [Indexed: 12/13/2022] Open
Abstract
Pharmacological interventions have been tested experimentally and clinically to prevent hydrocephalus and avoid the need for shunting beginning in the 1950s. Clinical trials of varied quality have not demonstrated lasting and convincing protective effects through manipulation of cerebrospinal fluid production, diuresis, blood clot fibrinolysis, or manipulation of fibrosis in the subarachnoid compartment, although there remains some promise in the latter areas. Acetazolamide bolus seems to be useful for predicting shunt response in adults with hydrocephalus. Neuroprotection in the situation of established hydrocephalus has been tested experimentally beginning more recently. Therapies designed to modify blood flow or pulsation, reduce inflammation, reduce oxidative damage, or protect neurons are so far of limited success; more experimental work is needed in these areas. As has been recommended for preclinical studies in stroke and brain trauma, stringent conditions should be met for preclinical studies in hydrocephalus.
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Affiliation(s)
- Marc R Del Bigio
- Department of Pathology, University of Manitoba; Children's Hospital Research Institute of Manitoba, Diagnostic Services Manitoba, 401 Brodie Centre, 715 McDermot Avenue, Winnipeg, MB, R3E 3P5, Canada.
| | - Domenico L Di Curzio
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada.
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35
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TRPV4 activation triggers the release of melatonin from human non-pigmented ciliary epithelial cells. Exp Eye Res 2015; 136:34-7. [DOI: 10.1016/j.exer.2015.04.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/10/2015] [Accepted: 04/27/2015] [Indexed: 11/20/2022]
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