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Zeng J, Lu Y, Chu H, Lu L, Chen Y, Ji K, Lin Y, Li J, Wang S. Research trends and frontier hotspots of TRPV1 based on bibliometric and visualization analyses. Heliyon 2024; 10:e24153. [PMID: 38293347 PMCID: PMC10827456 DOI: 10.1016/j.heliyon.2024.e24153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 11/30/2023] [Accepted: 01/04/2024] [Indexed: 02/01/2024] Open
Abstract
Background Transient receptor potential vanilloid type1 (TRPV1) is a non-selective cation channel with multiple activation mechanisms, which has received increasing attention since it was first cloned in 1997. Methods We used bibliometric and visualization analyses to evaluate the theme trends and knowledge structure of TRPV1 research-papers on TRPV1 from 2002 to 2022 obtained from the Web of Science Core Collection. VOSviewer and CiteSpace were used to analyze authors, institutions, countries, co-cited references, and keywords. Results A total of 7413 papers were included. The main research area of TRPV1 was neuroscience; the most published country was the United States, and the University of California, San Francisco, had the highest centrality. Two major collaborative sub-networks were formed between the authors. The distribution of keywords shows that TRPV1 was initially studied extensively, and the recent studies focused on TRPV1 structure and diseases. "Oxidative stress," "TRPV1 structure," "cancer," and "model" have been the research hotspots in recent years. Conclusions This research provides valuable information for the study of TRPV1. Disease research was focused on pain, cancer, and neurodegenerative diseases. Both agonists and antagonists of TRPV1 are gradually being used in clinical practice, and acupuncture was effective in treating TRPV1-mediated inflammatory pain. TRPV1 is involved in classical endogenous cannabis system signaling, and new signaling pathways continue to be revealed.
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Affiliation(s)
- Jingchun Zeng
- Rehabilitation Center, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Yiqian Lu
- The First Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Hui Chu
- The First Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Liming Lu
- Clinical Research and Data Center, South China Research Center for Acupuncture and Moxibustion, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Yuexuan Chen
- The First Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Kaisong Ji
- The First Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Yeze Lin
- Rehabilitation Center, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Jingjing Li
- Bao'an Traditional Chinese Medicine Hospital//Seventh Clinical Medical College of Guangzhou University of Traditional Chinese Medicine, Shenzhen, Guangdong, China
| | - Shuxin Wang
- Rehabilitation Center, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
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Minke B, Pak WL. The light-activated TRP channel: the founding member of the TRP channel superfamily. J Neurogenet 2022; 36:55-64. [PMID: 36217603 DOI: 10.1080/01677063.2022.2121824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The Drosophila light-activated Transient Receptor Potential (TRP) channel is the founding member of a large and diverse family of channel proteins. The Drosophila TRP (dTRP) channel, which generates the electrical response to light has been investigated in a great detail two decades before the first mammalian TRP channel was discovered. Thus, dTRP is unique among members of the TRP channel superfamily because its physiological role and the enzymatic cascade underlying its activation are established. In this article we outline the research leading to elucidation of dTRP as the light activated channel and focus on a major physiological property of the dTRP channel, which is indirect activation via a cascade of enzymatic reactions. These detailed pioneering studies, based on the genetic dissection approach, revealed that light activation of the Drosophila TRP channel is mediated by G-Protein-Coupled Receptor (GPCR)-dependent enzymatic cascade, in which phospholipase C β (PLC) is a crucial component. This physiological mechanism of Drosophila TRP channel activation was later found in mammalian TRPC channels. However, the initial studies on the mammalian TRPV1 channel indicated that it is activated directly by capsaicin, low pH and hot temperature (>42 °C). This mechanism of activation was apparently at odds with the activation mechanism of the TRPC channels in general and the Drosophila light activated TRP/TRPL channels in particular, which are target of a GPCR-activated PLC cascade. Subsequent studies have indicated that under physiological conditions TRPV1 is also target of a GPCR-activated PLC cascade in the generation of inflammatory pain. The Drosophila light-activated TRP channel is still a useful experimental paradigm because its physiological function as the light-activated channel is known, powerful genetic techniques can be applied to its further analysis, and signaling molecules involved in the activation of these channels are available.
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Affiliation(s)
- Baruch Minke
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada (IMRIC), Edmond and Lily Safra Center for Brain Sciences (ELSC), Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - William L Pak
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
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Abstract
Pertussis, also known as whooping cough, is a contagious respiratory disease caused by the Gram-negative bacterium Bordetella pertussis. This disease is characterized by severe and uncontrollable coughing, which imposes a significant burden on patients. However, its etiological agent and the mechanism are totally unknown because of a lack of versatile animal models that reproduce the cough. Here, we present a mouse model that reproduces coughing after intranasal inoculation with the bacterium or its components and demonstrate that lipooligosaccharide (LOS), pertussis toxin (PTx), and Vag8 of the bacterium cooperatively function to cause coughing. Bradykinin induced by LOS sensitized a transient receptor potential ion channel, TRPV1, which acts as a sensor to evoke the cough reflex. Vag8 further increased bradykinin levels by inhibiting the C1 esterase inhibitor, the major downregulator of the contact system, which generates bradykinin. PTx inhibits intrinsic negative regulation systems for TRPV1 through the inactivation of Gi GTPases. Our findings provide a basis to answer long-standing questions on the pathophysiology of pertussis cough.
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Gladkikh IN, Sintsova OV, Leychenko EV, Kozlov SA. TRPV1 Ion Channel: Structural Features, Activity Modulators, and Therapeutic Potential. BIOCHEMISTRY (MOSCOW) 2021; 86:S50-S70. [PMID: 33827400 DOI: 10.1134/s0006297921140054] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Although TRPV1 ion channel has been attracting researchers' attention for many years, its functions in animal organisms, the principles of regulation, and the involvement in pathological processes have not yet been fully clarified. Mutagenesis experiments and structural studies have identified the structural features of the channel and binding sites for its numerous ligands; however, these studies are far from conclusion. This review summarizes recent achievements in the TRPV1 research with special focus on structural and functional studies of the channel and on its ligands, which are extremely diverse in their nature and interaction specificity to TRPV1. Particular attention was given to the effects of numerous endogenous agonists and antagonists that can fine-tune the channel sensitivity to its usual activators, such as capsaicin, heat, acids, or their combination. In addition to the pain sensing not covered in this review, the TRPV1 channel was found to be involved in the regulation of many important physiological and pathological processes and, therefore, can be considered as a promising therapeutic target in the treatment of various diseases, such as pneumonia, ischemia, diabetes, epilepsy, schizophrenia, psoriasis, etc.
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Affiliation(s)
- Irina N Gladkikh
- Elyakov Pacific Institute of Bioorganic Chemistry, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia
| | - Oksana V Sintsova
- Elyakov Pacific Institute of Bioorganic Chemistry, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia
| | - Elena V Leychenko
- Elyakov Pacific Institute of Bioorganic Chemistry, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia
| | - Sergey A Kozlov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
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Jacob RS, Eichmann C, Dema A, Mercadante D, Selenko P. α-Synuclein plasma membrane localization correlates with cellular phosphatidylinositol polyphosphate levels. eLife 2021; 10:61951. [PMID: 33587036 PMCID: PMC7929559 DOI: 10.7554/elife.61951] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/12/2021] [Indexed: 12/11/2022] Open
Abstract
The Parkinson's disease protein α-synuclein (αSyn) promotes membrane fusion and fission by interacting with various negatively charged phospholipids. Despite postulated roles in endocytosis and exocytosis, plasma membrane (PM) interactions of αSyn are poorly understood. Here, we show that phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3), two highly acidic components of inner PM leaflets, mediate PM localization of endogenous pools of αSyn in A2780, HeLa, SK-MEL-2, and differentiated and undifferentiated neuronal SH-SY5Y cells. We demonstrate that αSyn binds to reconstituted PIP2 membranes in a helical conformation in vitro and that PIP2 synthesizing kinases and hydrolyzing phosphatases reversibly redistribute αSyn in cells. We further delineate that αSyn-PM targeting follows phosphoinositide-3 kinase (PI3K)-dependent changes of cellular PIP2 and PIP3 levels, which collectively suggests that phosphatidylinositol polyphosphates contribute to αSyn's function(s) at the plasma membrane.
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Affiliation(s)
- Reeba Susan Jacob
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Cédric Eichmann
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Alessandro Dema
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Davide Mercadante
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Philipp Selenko
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
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6
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Hu B, Boyle CA, Lei S. Activation of Oxytocin Receptors Excites Subicular Neurons by Multiple Signaling and Ionic Mechanisms. Cereb Cortex 2020; 31:2402-2415. [PMID: 33341872 DOI: 10.1093/cercor/bhaa363] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/01/2020] [Accepted: 11/02/2020] [Indexed: 12/14/2022] Open
Abstract
Oxytocin (OXT) is a nonapeptide that serves as a neuromodulator in the brain and a hormone participating in parturition and lactation in the periphery. The subiculum is the major output region of the hippocampus and an integral component in the networks that process sensory and motor cues to form a cognitive map encoding spatial, contextual, and emotional information. Whilst the subiculum expresses the highest OXT-binding sites and is the first brain region to be activated by peripheral application of OXT, the precise actions of OXT in the subiculum have not been determined. Our results demonstrate that application of the selective OXT receptor (OXTR) agonist, [Thr4,Gly7]-oxytocin (TGOT), excited subicular neurons via activation of TRPV1 channels, and depression of K+ channels. The OXTR-mediated excitation of subicular neurons required the functions of phospholipase Cβ, protein kinase C, and degradation of phosphatidylinositol 4,5-bisphosphate (PIP2). OXTR-elicited excitation of subicular neurons enhanced long-term potentiation via activation of TRPV1 channels. Our results provide a cellular and molecular mechanism to explain the physiological functions of OXT in the brain.
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Affiliation(s)
- Binqi Hu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Cody A Boyle
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Saobo Lei
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
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Rodrigues K, Batista-Silva H, Sousa de Moura KR, Van Der Kraak G, Mena Barreto Silva FR. Dibutyl phthalate rapidly alters calcium homeostasis in the gills of Danio rerio. CHEMOSPHERE 2020; 258:127408. [PMID: 32782161 DOI: 10.1016/j.chemosphere.2020.127408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/11/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
This study investigates the impacts of exposure to an environment Ca2+ challenge and the mechanism of action of dibutyl phthalate (DBP) on Ca2+ influx in the gills of Danio rerio. In vitro profile of 45Ca2+ influx in gills was verified through the basal time-course. Fish were exposed to low, normal and high Ca2+ concentrations (0.02, 0.7 and 2 mM) for 12 h. So, gills were morphologically analysed and ex vivo45Ca2+ influx at 30 and 60 min was determined. For the in vitro studies, gills were treated for 60 min with DBP (1 pM, 1 nM and 1 μM) with/without blockers/activators of ionic channels, Ca2+ chelator, inhibitors of ATPases, ionic exchangers and protein kinase C to study the mechanism of DBP-induced 45Ca2+ influx. Exposure to high environmental Ca2+ augmented 45Ca2+ influx when compared to fish exposed to normal and low Ca2+ concentrations. Additionally, histopathological changes were observed in the gills of fish maintained for 12 h in low and high Ca2+. In vitro exposure of gills to DBP (1 pM) disturbed Ca2+ homeostasis. DBP stimulated 45Ca2+ influx in gills through the transitory receptor potential vanilloid 1 (TRPV1), and reverse-mode Na+/Ca2+ exchanger (NCX) activation, protein kinase C and K+ channels and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA). These data suggest that in vivo short-term exposure of gills to low and high Ca2+ leads to 45Ca2+ influx and histopathological changes. Additionally, the DBP-induced rapid 45Ca2+ influx is mediated by TRPV1, NCX activation with the involvement of PKC, K+-channels and SERCA, thereby altering Ca2+ homeostasis.
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Affiliation(s)
- Keyla Rodrigues
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, CEP: 88040-900, Florianópolis, Santa Catarina, Brazil
| | - Hemily Batista-Silva
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, CEP: 88040-900, Florianópolis, Santa Catarina, Brazil
| | | | - Glen Van Der Kraak
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Fátima Regina Mena Barreto Silva
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, CEP: 88040-900, Florianópolis, Santa Catarina, Brazil.
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8
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Kumar R, Geron M, Hazan A, Priel A. Endogenous and Exogenous Vanilloids Evoke Disparate TRPV1 Activation to Produce Distinct Neuronal Responses. Front Pharmacol 2020; 11:903. [PMID: 32595512 PMCID: PMC7303340 DOI: 10.3389/fphar.2020.00903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 06/02/2020] [Indexed: 12/19/2022] Open
Abstract
Neuronal signals are processed along the nociceptive pathway to convey discriminative information, which would manifest in the produced pain sensation. The transient receptor potential vanilloid 1 (TRPV1), an important signaling complex in nociceptors termini, is activated by different noxious stimuli that underlie distinct pain sensations. For example, while endovanilloids are associated with inflammatory pain and hypersensitivity through TRPV1 activation, the exovanilloid toxin, capsaicin, evokes an acute pain by activating this channel. Differences in the TRPV1 activation profile evoked by exogenous and endogenous vanilloids were suggested to underlie this disparity in pain sensations. However, the cellular processes that lead to these differences in pain sensation mediated by the same channel are not fully understood. Here, we sought to describe the neuronal response of TRPV1-expressing nociceptors to exo-and endovanilloids. To this end, we performed current-clamp recordings in rat trigeminal neurons exposed to either capsaicin or intracellular endovanilloids produced downstream of the bradykinin receptor BK2. Our results show that lipoxygenase metabolites generate persistent TRPV1-dependent action potential firing while capsaicin evokes robust depolarization and high-frequency firing that is quickly terminated by depolarization block. Additionally, we found that a weak TRPV1 activation prolongs action potential firing. Overall, our results indicate different firing patterns evoked by inflammatory mediators and capsaicin via TRPV1 that correlate with the respective subsequent pain sensation. These findings also suggest that differences in neuronal activation stem from the variable degree of TRPV1 activation they produce.
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Affiliation(s)
- Rakesh Kumar
- Institute for Drug Research (IDR), School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Matan Geron
- Institute for Drug Research (IDR), School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adina Hazan
- Institute for Drug Research (IDR), School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Avi Priel
- Institute for Drug Research (IDR), School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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9
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Cohen E, Kumar R, Zinger T, Priel A, Treinin M. GTL-1, a Calcium Activated TRPM Channel, Enhances Nociception. Front Pharmacol 2020; 10:1567. [PMID: 32009965 PMCID: PMC6978279 DOI: 10.3389/fphar.2019.01567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 12/03/2019] [Indexed: 12/23/2022] Open
Abstract
C. elegans PVD neurons are conserved for morphology, function and molecular determinants with mammalian polymodal nociceptors. Functions of polymodal nociceptors require activities of multiple ion channels and receptors including members of the TRP family. GTL-1, a member of the TRPM subclass of TRP channels, was previously shown to amplify PVD-mediated responses to optogenetic stimuli. Here we characterize effects of GTL-1 on PVD-mediated behavioral responses to noxious stimuli. We show that GTL-1 is required within PVD for the immediate and enduring response to thermal (cold) stimuli. But, find no significant reduction in percent animals responding to single or to repeated noxious mechanical stimuli. Nevertheless, PVD specific knockdown of gtl-1expression reduces the magnitude of responses to noxious mechanical stimuli. To understand GTL-1's mechanism of action we expressed it in HEK293 cells. Our results show GTL-1-dependent currents induced by activation of a Gαq-coupled Designer Receptor Exclusively Activated by Designer Drugs (DREADD). In addition, using excised patches we show that GTL-1 can be activated by internal calcium. Our results are consistent with indirect, calcium dependent, activation of GTL-1 by noxious stimuli. This mechanism explains the GTL-1-dependent amplification of responses to multiple stimuli optogenetic and sensory in PVD.
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Affiliation(s)
- Emiliano Cohen
- Department of Medical Neurobiology, Hadassah-Medical School, Jerusalem, Israel
| | - Rakesh Kumar
- Faculty of Medicine, School of Pharmacy, The Institute for Drug Research, Hebrew University, Jerusalem, Israel
| | - Tal Zinger
- Department of Medical Neurobiology, Hadassah-Medical School, Jerusalem, Israel
| | - Avi Priel
- Faculty of Medicine, School of Pharmacy, The Institute for Drug Research, Hebrew University, Jerusalem, Israel
| | - Millet Treinin
- Department of Medical Neurobiology, Hadassah-Medical School, Jerusalem, Israel
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10
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Sun H, Meeker S, Undem BJ. Role of TRP channels in G q-coupled protease-activated receptor 1-mediated activation of mouse nodose pulmonary C-fibers. Am J Physiol Lung Cell Mol Physiol 2019; 318:L192-L199. [PMID: 31664854 DOI: 10.1152/ajplung.00301.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We evaluated the mechanisms underlying protease-activated receptor 1 (PAR1)-mediated activation of nodose C-fibers in mouse lungs. The PAR1-induced action potential discharge at the terminals was strongly inhibited in phospholipase C-β3 (PLCβ3)-deficient animals. At the level of the cell soma, PAR1 activation led to an increase in cytosolic calcium that was largely inhibited by transient receptor potential (TRP) A1 antagonism. Patch-clamp recordings, however, revealed that neither TRPA1 nor TRPV1 or any other ruthenium red-sensitive ion channels are required for the PAR1-mediated inward current or membrane depolarization in isolated nodose neurons. Consistent with these findings, PAR1-mediated action potential discharge in mouse lung nodose C-fiber terminals was unaltered in Trpa1/Trpv1 double-knockout animals and Trpc3/Trpc6 double-knockout animals. The activation of the C-fibers was also not inhibited by ruthenium red at concentrations that blocked TRPV1- and TRPA1-dependent responses. The biophysical data show that PAR1/Gq-mediated activation of nodose C-fibers may involve multiple ion channels downstream from PLCβ3 activation. TRPA1 is an ion channel that participates in PAR1/Gq-mediated elevation in intracellular calcium. There is little evidence, however, that TRPA1, TRPV1, TRPC3, TRPC6, or other ruthenium red-sensitive TRP channels are required for PAR1/Gq-PLCβ3-mediated membrane depolarization and action potential discharge in bronchopulmonary nodose C-fibers in the mouse.
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Affiliation(s)
- Hui Sun
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sonya Meeker
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Bradley J Undem
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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11
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Goto T, Nakagami G, Minematsu T, Tomida S, Shinoda M, Iwata K, Sanada H. Topically injected adrenocorticotropic hormone induces mechanical hypersensitivity on a full‐thickness cutaneous wound model in rats. Exp Dermatol 2019; 28:1010-1016. [DOI: 10.1111/exd.13994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 05/01/2019] [Accepted: 06/19/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Taichi Goto
- Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine The University of Tokyo Bunkyo‐ku Tokyo Japan
- Global Leadership Initiative for an Age‐Friendly Society The University of Tokyo Bunkyo‐ku Tokyo Japan
| | - Gojiro Nakagami
- Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine The University of Tokyo Bunkyo‐ku Tokyo Japan
- Division of Care Innovation, Global Nursing Research Center, Graduate School of Medicine The University of Tokyo Bunkyo‐ku Tokyo Japan
| | - Takeo Minematsu
- Division of Care Innovation, Global Nursing Research Center, Graduate School of Medicine The University of Tokyo Bunkyo‐ku Tokyo Japan
- Department of Skincare Science, Graduate School of Medicine The University of Tokyo, Bunkyo‐ku Tokyo Japan
| | - Sanai Tomida
- Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine The University of Tokyo Bunkyo‐ku Tokyo Japan
| | - Masamichi Shinoda
- Department of Physiology Nihon University School of Dentistry Chiyoda‐ku Tokyo Japan
| | - Koichi Iwata
- Department of Physiology Nihon University School of Dentistry Chiyoda‐ku Tokyo Japan
| | - Hiromi Sanada
- Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine The University of Tokyo Bunkyo‐ku Tokyo Japan
- Division of Care Innovation, Global Nursing Research Center, Graduate School of Medicine The University of Tokyo Bunkyo‐ku Tokyo Japan
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12
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Dong H, Tang B, Jiang Y, Mittal RK. Na + /Ca 2+ exchanger 1 is a key mechanosensitive molecule of the esophageal myenteric neurons. Acta Physiol (Oxf) 2019; 225:e13223. [PMID: 30466198 DOI: 10.1111/apha.13223] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 11/14/2018] [Accepted: 11/17/2018] [Indexed: 12/12/2022]
Abstract
AIM Our earlier studies showed that mechanical stretch activates inhibitory motor neurons of the oesophagus; however, the underlying molecular mechanisms are unclear. Here, we sought to examine if Na+ /Ca2+ exchanger 1 (NCX1) is responsible for the mechanosensitivity in the esophageal myenteric neurons (EMN) of rats and humans. METHODS The function of NCX1 in primary culture of neurons was determined using calcium imaging, and mechanosensitivity was tested using osmotic stretch and direct mechanical stretch. Axial stretch-induced relaxation of the lower esophageal sphincter (LES) was also studied in vivo in rats. RESULTS The expression and co-localization of NCX1 with nNOS were identified in the EMN from both rats and humans. The extracellular Ca2+ entry caused by ATP through purinergic signalling in the rat EMN was significantly inhibited by selective NCX blockers. Removal of extracellular Na+ to activate the Ca2+ entry mode of NCX1 induced an increase in the cytoplasmic calcium ([Ca2+ ]cyt ), which was attenuated by NCX blockers. Osmotic stretch and mechanical stretch-induced [Ca2+ ]cyt signalling in the rat and human EMN were attenuated by NCX blockers as well as specific NCX1 knockdown. Osmotic stretch and mechanical stretch also induced [Ca2+ ]cyt signalling in the Chinese hamster ovary (CHO) cells with NCX1 over-expression, which was attenuated by NCX blockers. Finally, NCX blockade inhibited axial stretch-activated LES relaxation in vivo experiments in the rats. CONCLUSIONS We demonstrate a novel NCX1/Ca2+ pathway in the mechanosensitive neurons of rat and human oesophagus, which may provide a potential therapeutic target for the treatment of oesophageal motility disorders.
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Affiliation(s)
- Hui Dong
- Department of Gastroenterology, Xinqiao Hospital Third Military Meical University Chongqing China
- Department of Medicine University of California San Diego California
- San Diego VA Healthcare System San Diego California
| | - Bo Tang
- Department of Gastroenterology, Xinqiao Hospital Third Military Meical University Chongqing China
- Department of Medicine University of California San Diego California
- San Diego VA Healthcare System San Diego California
| | - Yanfen Jiang
- Department of Medicine University of California San Diego California
- San Diego VA Healthcare System San Diego California
| | - Ravinder K. Mittal
- Department of Medicine University of California San Diego California
- San Diego VA Healthcare System San Diego California
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13
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Maatuf Y, Geron M, Priel A. The Role of Toxins in the Pursuit for Novel Analgesics. Toxins (Basel) 2019; 11:toxins11020131. [PMID: 30813430 PMCID: PMC6409898 DOI: 10.3390/toxins11020131] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/17/2019] [Accepted: 02/20/2019] [Indexed: 12/19/2022] Open
Abstract
Chronic pain is a major medical issue which reduces the quality of life of millions and inflicts a significant burden on health authorities worldwide. Currently, management of chronic pain includes first-line pharmacological therapies that are inadequately effective, as in just a portion of patients pain relief is obtained. Furthermore, most analgesics in use produce severe or intolerable adverse effects that impose dose restrictions and reduce compliance. As the majority of analgesic agents act on the central nervous system (CNS), it is possible that blocking pain at its source by targeting nociceptors would prove more efficient with minimal CNS-related side effects. The development of such analgesics requires the identification of appropriate molecular targets and thorough understanding of their structural and functional features. To this end, plant and animal toxins can be employed as they affect ion channels with high potency and selectivity. Moreover, elucidation of the toxin-bound ion channel structure could generate pharmacophores for rational drug design while favorable safety and analgesic profiles could highlight toxins as leads or even as valuable therapeutic compounds themselves. Here, we discuss the use of plant and animal toxins in the characterization of peripherally expressed ion channels which are implicated in pain.
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Affiliation(s)
- Yossi Maatuf
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Matan Geron
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Avi Priel
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
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Abstract
Many neurotoxins inflict pain by targeting receptors expressed on nociceptors, such as the polymodal cationic channel TRPV1. The tarantula double-knot toxin (DkTx) is a peptide with an atypical bivalent structure, providing it with the unique capability to lock TRPV1 in its open state and evoke an irreversible channel activation. Here, we describe a distinct gating mechanism of DkTx-evoked TRPV1 activation. Interestingly, DkTx evokes significantly smaller TRPV1 macroscopic currents than capsaicin, with a significantly lower unitary conductance. Accordingly, while capsaicin evokes aversive behaviors in TRPV1-transgenic Caenorhabditis elegans, DkTx fails to evoke such response at physiological concentrations. To determine the structural feature(s) responsible for this phenomenon, we engineered and evaluated a series of mutated toxins and TRPV1 channels. We found that elongating the DkTx linker, which connects its two knots, increases channel conductance compared with currents elicited by the native toxin. Importantly, deletion of the TRPV1 pore turret, a stretch of amino acids protruding out of the channel's outer pore region, is sufficient to produce both full conductance and aversive behaviors in response to DkTx. Interestingly, this deletion decreases the capsaicin-evoked channel activation. Taken together with structure modeling analysis, our results demonstrate that the TRPV1 pore turret restricts DkTx-mediated pore opening, probably through steric hindrance, limiting the current size and mitigating the evoked downstream physiological response. Overall, our findings reveal that DkTx and capsaicin elicit distinct TRPV1 gating mechanisms and subsequent pain responses. Our results also indicate that the TRPV1 pore turret regulates the mechanisms of channel gating and permeation.
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15
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Carrasco C, Naziroǧlu M, Rodríguez AB, Pariente JA. Neuropathic Pain: Delving into the Oxidative Origin and the Possible Implication of Transient Receptor Potential Channels. Front Physiol 2018; 9:95. [PMID: 29491840 PMCID: PMC5817076 DOI: 10.3389/fphys.2018.00095] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/29/2018] [Indexed: 12/25/2022] Open
Abstract
Currently, neuropathic pain is an underestimated socioeconomic health problem affecting millions of people worldwide, which incidence may increase in the next years due to chronification of several diseases, such as cancer and diabetes. Growing evidence links neuropathic pain present in several disorders [i.e., spinal cord injury (SCI), cancer, diabetes and alcoholism] to central sensitization, as a global result of mitochondrial dysfunction induced by oxidative and nitrosative stress. Additionally, inflammatory signals and the overload in intracellular calcium ion could be also implicated in this complex network that has not yet been elucidated. Recently, calcium channels namely transient receptor potential (TRP) superfamily, including members of the subfamilies A (TRAP1), M (TRPM2 and 7), and V (TRPV1 and 4), have demonstrated to play a role in the nociception mediated by sensory neurons. Therefore, as neuropathic pain could be a consequence of the imbalance between reactive oxygen species and endogen antioxidants, antioxidant supplementation may be a treatment option. This kind of therapy would exert its beneficial action through antioxidant and immunoregulatory functions, optimizing mitochondrial function and even increasing the biogenesis of this vital organelle; on balance, antioxidant supplementation would improve the patient's quality of life. This review seeks to deepen on current knowledge about neuropathic pain, summarizing clinical conditions and probable causes, the relationship existing between oxidative stress, mitochondrial dysfunction and TRP channels activation, and scientific evidence related to antioxidant supplementation.
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Affiliation(s)
- Cristina Carrasco
- Department of Physiology, Faculty of Sciences, University of Extremadura, Badajoz, Spain
| | - Mustafa Naziroǧlu
- Neuroscience Research Center, Suleyman Demirel University, Isparta, Turkey
| | - Ana B Rodríguez
- Department of Physiology, Faculty of Sciences, University of Extremadura, Badajoz, Spain
| | - José A Pariente
- Department of Physiology, Faculty of Sciences, University of Extremadura, Badajoz, Spain
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16
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Geron M, Hazan A, Priel A. Animal Toxins Providing Insights into TRPV1 Activation Mechanism. Toxins (Basel) 2017; 9:toxins9100326. [PMID: 29035314 PMCID: PMC5666373 DOI: 10.3390/toxins9100326] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/13/2017] [Accepted: 10/13/2017] [Indexed: 02/06/2023] Open
Abstract
Beyond providing evolutionary advantages, venoms offer unique research tools, as they were developed to target functionally important proteins and pathways. As a key pain receptor in the nociceptive pathway, transient receptor potential vanilloid 1 (TRPV1) of the TRP superfamily has been shown to be a target for several toxins, as a way of producing pain to deter predators. Importantly, TRPV1 is involved in thermoregulation, inflammation, and acute nociception. As such, toxins provide tools to understand TRPV1 activation and modulation, a critical step in advancing pain research and the development of novel analgesics. Indeed, the phytotoxin capsaicin, which is the spicy chemical in chili peppers, was invaluable in the original cloning and characterization of TRPV1. The unique properties of each subsequently characterized toxin have continued to advance our understanding of functional, structural, and biophysical characteristics of TRPV1. By building on previous reviews, this work aims to provide a comprehensive summary of the advancements made in TRPV1 research in recent years by employing animal toxins, in particular DkTx, RhTx, BmP01, Echis coloratus toxins, APHCs and HCRG21. We examine each toxin’s functional aspects, behavioral effects, and structural features, all of which have contributed to our current knowledge of TRPV1. We additionally discuss the key features of TRPV1’s outer pore domain, which proves to be the target of the currently discussed toxins.
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Affiliation(s)
- Matan Geron
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Adina Hazan
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Avi Priel
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
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Randhawa PK, Jaggi AS. A Review on Potential Involvement of TRPV1 Channels in Ischemia–Reperfusion Injury. J Cardiovasc Pharmacol Ther 2017; 23:38-45. [DOI: 10.1177/1074248417707050] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Besides functioning as thermosensors, transient receptor potential vanilloid 1 (TRPV1) channels play a pivotal role in ischemia–reperfusion injury. Transient receptor potential vanilloid 1 channel activation attenuates ischemia–reperfusion-induced injury in various organs including the heart, lungs, kidneys, and the brain. Transient receptor potential vanilloid 1 channels are expressed on the sensory neurons innervating the myocardium, ventricles of the heart, epicardial surface of the heart, endothelial cells, and the vascular smooth muscle cells. During ischemic conditions, activation of TRPV1 channels on the perivascular nerves stimulates the release of calcitonin gene-related peptide and substance P to produce cardioprotection. Furthermore, TRPV1 channel activation reduces the generation of free radicals and inflammatory cytokines, inhibits neutrophil infiltration, and enhances the production of anti-inflammatory cytokines to reduce ischemia–reperfusion-induced tissue injury. The present review describes the potential involvement of TRPV1 channels and the signaling cascade in attenuating ischemia–reperfusion injury in various organs.
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Affiliation(s)
- Puneet Kaur Randhawa
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University Patiala, Patiala, Punjab, India
| | - Amteshwar Singh Jaggi
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University Patiala, Patiala, Punjab, India
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18
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The Phosphorylation State of the Drosophila TRP Channel Modulates the Frequency Response to Oscillating Light In Vivo. J Neurosci 2017; 37:4213-4224. [PMID: 28314815 DOI: 10.1523/jneurosci.3670-16.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/13/2017] [Accepted: 02/28/2017] [Indexed: 11/21/2022] Open
Abstract
Drosophila photoreceptors respond to oscillating light of high frequency (∼100 Hz), while the detected maximal frequency is modulated by the light rearing conditions, thus enabling high sensitivity to light and high temporal resolution. However, the molecular basis for this adaptive process is unclear. Here, we report that dephosphorylation of the light-activated transient receptor potential (TRP) ion channel at S936 is a fast, graded, light-dependent, and Ca2+-dependent process that is partially modulated by the rhodopsin phosphatase retinal degeneration C (RDGC). Electroretinogram measurements of the frequency response to oscillating lights in vivo revealed that dark-reared flies expressing wild-type TRP exhibited a detection limit of oscillating light at relatively low frequencies, which was shifted to higher frequencies upon light adaptation. Strikingly, preventing phosphorylation of the S936-TRP site by alanine substitution in transgenic Drosophila (trpS936A ) abolished the difference in frequency response between dark-adapted and light-adapted flies, resulting in high-frequency response also in dark-adapted flies. In contrast, inserting a phosphomimetic mutation by substituting the S936-TRP site to aspartic acid (trpS936D ) set the frequency response of light-adapted flies to low frequencies typical of dark-adapted flies. Light-adapted rdgC mutant flies showed relatively high S936-TRP phosphorylation levels and light-dark phosphorylation dynamics. These findings suggest that RDGC is one but not the only phosphatase involved in pS936-TRP dephosphorylation. Together, this study indicates that TRP channel dephosphorylation is a regulatory process that affects the detection limit of oscillating light according to the light rearing condition, thus adjusting dynamic processing of visual information under varying light conditions.SIGNIFICANCE STATEMENTDrosophila photoreceptors exhibit high temporal resolution as manifested in frequency response to oscillating light of high frequency (≤∼100 Hz). Light rearing conditions modulate the maximal frequency detected by photoreceptors, thus enabling them to maintain high sensitivity to light and high temporal resolution. However, the precise mechanisms for this process are not fully understood. Here, we show by combination of biochemistry and in vivo electrophysiology that transient receptor potential (TRP) channel dephosphorylation at a specific site is a fast, light-activated and Ca2+-dependent regulatory process. TRP dephosphorylation affects the detection limit of oscillating light according to the adaptation state of the photoreceptor cells by shifting the detection limit to higher frequencies upon light adaptation. This novel mechanism thus adjusts dynamic processing of visual information under varying light conditions.
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