1
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Li S, Zheng J. How much does TRPV1 deviate from an ideal MWC-type protein? Biophys J 2024; 123:2136-2144. [PMID: 38582967 PMCID: PMC11309965 DOI: 10.1016/j.bpj.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/06/2023] [Accepted: 04/03/2024] [Indexed: 04/08/2024] Open
Abstract
Many ion channels are known to behave as an allosteric protein, coupling environmental stimuli captured by specialized sensing domains to the opening of a central pore. The classic Monod-Wyman-Changeux (MWC) model, originally proposed to describe binding of gas molecules to hemoglobin, has been widely used as a framework for analyzing ion channel gating. Here, we address the issue of how accurately the MWC model predicts activation of the capsaicin receptor TRPV1 by vanilloids. Taking advantage of a concatemeric design that makes it possible to lock TRPV1 in states with zero to four bound vanilloid molecules, we showed quantitatively that the overall gating behavior is satisfactorily predicted by the MWC model. There is, however, a small yet detectable subunit position effect: ligand binding to two kitty-corner subunits is 0.3-0.4 kcal/mol more effective in inducing opening than binding to two neighbor subunits. This difference-less than 10% of the overall energetic contribution from ligand binding-might be due to the restriction on subunit arrangement imposed by the planar membrane; if this is the case, then the position effect is not expected in hemoglobin, in which each subunit is related equivalently to all the other subunits.
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Affiliation(s)
- Shisheng Li
- Department of Physiology and Membrane Biology, University of California at Davis, School of Medicine, Davis, California
| | - Jie Zheng
- Department of Physiology and Membrane Biology, University of California at Davis, School of Medicine, Davis, California.
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2
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Dewaker V, Sharma AR, Debnath U, Park ST, Kim HS. Insights from molecular dynamics simulations of TRPV1 channel modulators in pain. Drug Discov Today 2023; 28:103798. [PMID: 37838068 DOI: 10.1016/j.drudis.2023.103798] [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: 07/28/2023] [Revised: 09/28/2023] [Accepted: 10/09/2023] [Indexed: 10/16/2023]
Abstract
TRPV1 is a nonselective cation channel vital for detecting noxious stimuli (heat, acid, capsaicin). Its role in pain makes it a potential drug target for chronic pain management, migraines, and related disorders. This review updates molecular dynamics (MD) simulation studies on the TRPV1 channel, focusing on its gating mechanism, ligand-binding sites, and implications for drug design. The article also explores challenges in developing modulators, SAR optimization, and clinical trial studies. Efforts have been undertaken to concisely present MD simulation findings, with a focus on their relevance to drug discovery.
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Affiliation(s)
- Varun Dewaker
- Institute of New Frontier Research Team, Hallym University, Chuncheon-si 24252, Gangwon-do, Republic of Korea
| | - Ashish R Sharma
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon-si 24252, Gangwon-do, Republic of Korea
| | - Utsab Debnath
- School of Health Sciences & Technology, UPES, Dehradun, Uttarakhand 248007, India
| | - Sung Taek Park
- Institute of New Frontier Research Team, Hallym University, Chuncheon-si 24252, Gangwon-do, Republic of Korea; Department of Obstetrics and Gynecology, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07441, Republic of Korea; EIONCELL Inc., Chuncheon 24252, Republic of Korea
| | - Hyeong Su Kim
- Institute of New Frontier Research Team, Hallym University, Chuncheon-si 24252, Gangwon-do, Republic of Korea; Division of Hemato-Oncology, Department of Internal Medicine, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07441, Republic of Korea; EIONCELL Inc., Chuncheon 24252, Republic of Korea.
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3
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Li S, Zheng J. The capsaicin binding affinity of wildtype and mutant TRPV1 ion channels. J Biol Chem 2023; 299:105268. [PMID: 37734552 PMCID: PMC10616419 DOI: 10.1016/j.jbc.2023.105268] [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: 07/12/2023] [Revised: 09/03/2023] [Accepted: 09/12/2023] [Indexed: 09/23/2023] Open
Abstract
Vanilloids such as capsaicin and resiniferatoxin are highly selective and potent activators for transient receptor potential vanilloid subfamily, member 1, a nociceptor for heat and pain perception. However, the intrinsic vanilloid binding affinity, key for understanding transient receptor potential vanilloid subfamily, member 1 function, remains unknown despite intensive investigations by electrophysiological, structural, and computational methods. In this study, we determined capsaicin binding affinity under physiological conditions by isolating individual binding steps to each subunit with concatemers. We estimated the capsaicin association constant of a wildtype subunit to be in the order of 106 M-1 and that of the Y511A mutant subunit to be a hundred times lower, in the order of 104 M-1. The Y511A mutation, located at the entrance of the vanilloid binding pocket, reduces binding affinity without a noticeable effect on activation gating. We further affirmed that there is little cooperativity between vanilloid binding steps. Models based on independent binding and equally cooperative subunit gating can accurately describe capsaicin activation.
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Affiliation(s)
- Shisheng Li
- Department of Physiology and Membrane Biology, University of California at Davis, School of Medicine, Davis California, USA
| | - Jie Zheng
- Department of Physiology and Membrane Biology, University of California at Davis, School of Medicine, Davis California, USA.
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4
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Li S, Nguyen PT, Vu S, Yarov-Yarovoy V, Zheng J. Opening of capsaicin receptor TRPV1 is stabilized equally by its four subunits. J Biol Chem 2023; 299:104828. [PMID: 37196769 PMCID: PMC10318505 DOI: 10.1016/j.jbc.2023.104828] [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: 02/25/2023] [Revised: 05/04/2023] [Accepted: 05/10/2023] [Indexed: 05/19/2023] Open
Abstract
Capsaicin receptor TRPV1 is a nociceptor for vanilloid molecules, such as capsaicin and resiniferatoxin (RTX). Even though cryo-EM structures of TRPV1 in complex with these molecules are available, how their binding energetically favors the open conformation is not known. Here, we report an approach to control the number of bound RTX molecules (0-4) in functional rat TRPV1. The approach allowed direct measurements of each of the intermediate open states under equilibrium conditions at both macroscopic and single-molecule levels. We found that RTX binding to each of the four subunits contributes virtually the same activation energy, which we estimated to be 1.70 to 1.86 kcal/mol and found to arise predominately from destabilizing the closed conformation. We further showed that sequential bindings of RTX increase open probability without altering single-channel conductance, confirming that there is likely a single open-pore conformation for TRPV1 activated by RTX.
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Affiliation(s)
- Shisheng Li
- Department of Physiology and Membrane Biology, School of Medicine, University of California at Davis, Davis, California, USA
| | - Phuong T Nguyen
- Department of Physiology and Membrane Biology, School of Medicine, University of California at Davis, Davis, California, USA
| | - Simon Vu
- Department of Physiology and Membrane Biology, School of Medicine, University of California at Davis, Davis, California, USA
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, School of Medicine, University of California at Davis, Davis, California, USA
| | - Jie Zheng
- Department of Physiology and Membrane Biology, School of Medicine, University of California at Davis, Davis, California, USA.
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5
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Fiszman S, Laguna L. Food design for safer swallowing: focusing on texture-modified diets and sensory stimulation of swallowing via TRP activation. Curr Opin Food Sci 2023. [DOI: 10.1016/j.cofs.2023.101000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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6
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Roles of Ca2+, Mg2+, and Ba2+ Cations in the Regulation of TRPV1 Channels in Rat DRG Neurons. NEUROPHYSIOLOGY+ 2021. [DOI: 10.1007/s11062-021-09899-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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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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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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Yin Y, Dong Y, Vu S, Yang F, Yarov‐Yarovoy V, Tian Y, Zheng J. Structural mechanisms underlying activation of TRPV1 channels by pungent compounds in gingers. Br J Pharmacol 2019; 176:3364-3377. [PMID: 31207668 PMCID: PMC6692589 DOI: 10.1111/bph.14766] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/21/2019] [Accepted: 05/29/2019] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE Like chili peppers, gingers produce pungent stimuli by a group of vanilloid compounds that activate the nociceptive transient receptor potential vanilloid 1 (TRPV1) ion channel. How these compounds interact with TRPV1 remains unclear. EXPERIMENTAL APPROACH We used computational structural modelling, functional tests (electrophysiology and calcium imaging), and mutagenesis to investigate the structural mechanisms underlying ligand-channel interactions. KEY RESULTS The potency of three principal pungent compounds from ginger -shogaol, gingerol, and zingerone-depends on the same two residues in the TRPV1 channel that form a hydrogen bond with the chili pepper pungent compound, capsaicin. Computational modelling revealed binding poses of these ginger compounds similar to those of capsaicin, including a "head-down tail-up" orientation, two specific hydrogen bonds, and important contributions of van der Waals interactions by the aliphatic tail. Our study also identified a novel horizontal binding pose of zingerone that allows it to directly interact with the channel pore when bound inside the ligand-binding pocket. These observations offer a molecular level explanation for how unique structures in the ginger compounds affect their channel activation potency. CONCLUSIONS AND IMPLICATIONS Mechanistic insights into the interactions of ginger compounds and the TRPV1 cation channel should help guide drug discovery efforts to modulate nociception.
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Affiliation(s)
- Yue Yin
- Department of PharmacologyQingdao University School of PharmacyQingdaoShandongChina
| | - Yawen Dong
- Department of PharmacologyQingdao University School of PharmacyQingdaoShandongChina
| | - Simon Vu
- Department of Physiology and Membrane BiologyUC Davis School of MedicineDavisCAUSA
| | - Fan Yang
- Department of Biophysics and Kidney Disease Center, First Affiliated Hospital, Institute of Neuroscience, National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical NeurobiologyZhejiang University School of MedicineHangzhouZhejiangChina
| | | | - Yuhua Tian
- Department of PharmacologyQingdao University School of PharmacyQingdaoShandongChina
| | - Jie Zheng
- Department of Physiology and Membrane BiologyUC Davis School of MedicineDavisCAUSA
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10
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Upadhyay E, Mohammad AlMass AA, Dasgupta N, Rahman S, Kim J, Datta M. Assessment of Occupational Health Hazards Due to Particulate Matter Originated from Spices. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16091519. [PMID: 31035724 PMCID: PMC6538991 DOI: 10.3390/ijerph16091519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/18/2019] [Accepted: 04/23/2019] [Indexed: 11/16/2022]
Abstract
Spices have been known for their various health activities; however, they also possess the allergic potential for the respiratory system and the skin as they are fine particulate matter. Persons involved in spice agriculture and food industries are at greater risk since they are exposed to a considerable amount of combustible dust, which may be the cause of fire and explosion and adversely affect the health. These workers may experience allergy, long-term and short-term respiratory issues including occupational asthma, dermatitis, etc. Some spices induce T cell-based inflammatory reaction upon contact recognition of the antigen. Antigen Presenting Cells (APC) on binding to the causative metabolite results in activation of macrophages by allergen cytokine interleukin (IL)-12 and tumor necrosis factor-beta (TNF). Cross-reactivity for protein allergens is another factor which seems to be a significant trigger for the stimulation of allergic reactions. Thus, it was imperative to perform a systematic review along with bioinformatics based representation of some evident allergens has been done to identify the overall conservation of epitopes. In the present manuscript, we have covered a multifold approach, i.e., to categorize the spice particles based on a clear understanding about nature, origin, mechanisms; to assess metabolic reactions of the particles after exposure as well as knowledge on the conditions of exposure along with associated potential health effects. Another aim of this study is to provide some suggestions to prevent and to control the exposure up to some extent.
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Affiliation(s)
- Era Upadhyay
- Amity institute of Biotechnology, Amity University Rajasthan, Jaipur, Rajasthan 302 002, India.
| | - Afnan Ahmad Mohammad AlMass
- Emergency Medicine Department, King Saud University Medical City, King Saud University, Riyadh 11321, Saudi Arabia.
| | - Nandita Dasgupta
- Department of Biotechnology, Institute of Engineering and Technology, Dr. APJ Abdul Kalam Technical University, Lucknow, Uttar Pradesh 226031, India.
| | - Safikur Rahman
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 712-749, Korea.
| | - Jihoe Kim
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 712-749, Korea.
| | - Manali Datta
- Amity institute of Biotechnology, Amity University Rajasthan, Jaipur, Rajasthan 302 002, India.
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11
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Panchal SK, Bliss E, Brown L. Capsaicin in Metabolic Syndrome. Nutrients 2018; 10:E630. [PMID: 29772784 PMCID: PMC5986509 DOI: 10.3390/nu10050630] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/07/2018] [Accepted: 05/14/2018] [Indexed: 12/21/2022] Open
Abstract
Capsaicin, the major active constituent of chilli, is an agonist on transient receptor potential vanilloid channel 1 (TRPV1). TRPV1 is present on many metabolically active tissues, making it a potentially relevant target for metabolic interventions. Insulin resistance and obesity, being the major components of metabolic syndrome, increase the risk for the development of cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. In vitro and pre-clinical studies have established the effectiveness of low-dose dietary capsaicin in attenuating metabolic disorders. These responses of capsaicin are mediated through activation of TRPV1, which can then modulate processes such as browning of adipocytes, and activation of metabolic modulators including AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α (PPARα), uncoupling protein 1 (UCP1), and glucagon-like peptide 1 (GLP-1). Modulation of these pathways by capsaicin can increase fat oxidation, improve insulin sensitivity, decrease body fat, and improve heart and liver function. Identifying suitable ways of administering capsaicin at an effective dose would warrant its clinical use through the activation of TRPV1. This review highlights the mechanistic options to improve metabolic syndrome with capsaicin.
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Affiliation(s)
- Sunil K Panchal
- Functional Foods Research Group, University of Southern Queensland, Toowoomba QLD 4350, Australia.
| | - Edward Bliss
- Functional Foods Research Group, University of Southern Queensland, Toowoomba QLD 4350, Australia.
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba QLD 4350, Australia.
| | - Lindsay Brown
- Functional Foods Research Group, University of Southern Queensland, Toowoomba QLD 4350, Australia.
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba QLD 4350, Australia.
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12
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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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13
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Mostinski Y, Noy G, Kumar R, Tsvelikhovsky D, Priel A. Tricyclic Spirolactones as Modular TRPV1 Synthetic Agonists. ACS Chem Neurosci 2017; 8:1688-1696. [PMID: 28520395 DOI: 10.1021/acschemneuro.7b00127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
TRPV1 is a prominent signal integrator of the pain system, known to be activated by vanilloids, a family of endogenous and exogenous pain-evoking molecules, through the vanilloid-binding site (VBS). The extensive preclinical profiling of small molecule inhibitors provides intriguing evidence that TRPV1 inhibition can be a useful therapeutic approach. However, the dissimilarity of chemical species that activate TRPV1 creates a major obstacle to understanding the molecular mechanism of pain induction, which is viewed as a pivotal trait of the somatosensory system. Here, we establish the existence of a unique family of synthetic agonists that interface with TRPV1 through the VBS, containing none of the molecular domains previously believed to be required for this interaction. The overarching value obtained from our inquiry is the novel advancement of the existing TRPV1 activation model. These findings uncover new potential in the area of pain treatment, providing a novel synthetic platform.
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Affiliation(s)
- Yelena Mostinski
- The
Institute for Drug Research, Division of Medicinal Chemistry, School
of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Gilad Noy
- The
Institute for Drug Research, Division of Pharmacology, School of Pharmacy,
Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Rakesh Kumar
- The
Institute for Drug Research, Division of Pharmacology, School of Pharmacy,
Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Dmitry Tsvelikhovsky
- The
Institute for Drug Research, Division of Medicinal Chemistry, School
of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Avi Priel
- The
Institute for Drug Research, Division of Pharmacology, School of Pharmacy,
Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
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14
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Geron M, Hazan A, Priel A. Controllable Ion Channel Expression through Inducible Transient Transfection. J Vis Exp 2017. [PMID: 28287552 DOI: 10.3791/55370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Transfection, the delivery of foreign nucleic acids into a cell, is a powerful tool in protein research. Through this method, ion channels can be investigated through electrophysiological analysis, biochemical characterization, mutational studies, and their effects on cellular processes. Transient transfections offer a simple protocol in which the protein becomes available for analysis within a few hours to days. Although this method presents a relatively straightforward and time efficient protocol, one of the critical components is calibrating the expression of the gene of interest to physiological relevant levels or levels that are suitable for analysis. To this end, many different approaches that offer the ability to control the expression of the gene of interest have emerged. Several stable cell transfection protocols provide a way to permanently introduce a gene of interest into the cellular genome under the regulation of a tetracycline-controlled transcriptional activation. While this technique produces reliable expression levels, each gene of interest requires a few weeks of skilled work including calibration of a killing curve, selection of cell colonies, and overall more resources. Here we present a protocol that uses transient transfection of the Transient Receptor Potential cation channel subfamily V member 1 (TRPV1) gene in an inducible system as an efficient way to express a protein in a controlled manner which is essential in ion channel analysis. We demonstrate that using this technique, we are able to perform calcium imaging, whole cell, and single channel analysis with controlled channel levels required for each type of data collection with a single transfection. Overall, this provides a replicable technique that can be used to study ion channels structure and function.
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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 (HUJI)
| | - Adina Hazan
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem (HUJI)
| | - Avi Priel
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem (HUJI);
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15
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Geron M, Kumar R, Matzner H, Lahiani A, Gincberg G, Cohen G, Lazarovici P, Priel A. Protein toxins of the Echis coloratus viper venom directly activate TRPV1. Biochim Biophys Acta Gen Subj 2017; 1861:615-623. [PMID: 28063984 DOI: 10.1016/j.bbagen.2017.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 12/13/2016] [Accepted: 01/03/2017] [Indexed: 12/23/2022]
Abstract
BACKGROUND Peptide and protein toxins are essential tools to dissect and probe the biology of their target receptors. Venoms target vital physiological processes to evoke pain. Snake venoms contain various factors with the ability to evoke, enhance and sustain pain sensation. While a number of venom-derived toxins were shown to directly target TRPV1 channels expressed on somatosensory nerve terminals to evoke pain response, such toxins were yet to be identified in snake venoms. METHODS We screened Echis coloratus saw-scaled viper venom's protein fractions isolated by reversed phase HPLC for their ability to activate TRPV1 channels. To this end, we employed heterologous systems to analyze TRPV1 and NGF pathways by imaging and electrophysiology, combined with molecular biology, biochemical, and pharmacological tools. RESULTS We identified TRPV1 activating proteins in the venom of Echis coloratus that produce a channel-dependent increase in intracellular calcium and outwardly rectifying currents in neurons and heterologous systems. Interestingly, channel activation was not mediated by any of its known toxin binding sites. Moreover, although NGF neurotropic activity was detected in this venom, TRPV1 activation was independent of NGF receptors. CONCLUSIONS Echis coloratus venom contains proteins with the ability to directly activate TRPV1. This activity is independent of the NGF pathway and is not mediated by known TRPV1 toxins' binding sites. GENERAL SIGNIFICANCE Our results could facilitate the discovery of new toxins targeting TRPV1 to enhance current understanding of this receptor activation mechanism. Furthermore, the findings of this study provide insight into the mechanism through which snakes' venom elicit pain.
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Affiliation(s)
- Matan Geron
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Rakesh Kumar
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Henry Matzner
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Adi Lahiani
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Galit Gincberg
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Gadi Cohen
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Philip Lazarovici
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Avi Priel
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel.
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16
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Kumar R, Hazan A, Geron M, Steinberg R, Livni L, Matzner H, Priel A. Activation of transient receptor potential vanilloid 1 by lipoxygenase metabolites depends on PKC phosphorylation. FASEB J 2016; 31:1238-1247. [PMID: 27986808 DOI: 10.1096/fj.201601132r] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 12/06/2016] [Indexed: 11/11/2022]
Abstract
Peripheral neuronal activation by inflammatory mediators is a multifaceted physiological response that involves a multitude of regulated cellular functions. One key pathway that has been shown to be involved in inflammatory pain is Gq/GPCR, whose activation by inflammatory mediators is followed by the regulated response of the cation channel transient receptor potential vanilloid 1 (TRPV1). However, the mechanism that underlies TRPV1 activation downstream of the Gq/GPCR pathway has yet to be fully defined. In this study, we employ pharmacological and molecular biology tools to dissect this activation mechanism via perforated-patch recordings and calcium imaging of both neurons and a heterologous system. We showed that TRPV1 activity downstream of Gq/GPCR activation only produced a subdued current, which was noticeably different from the robust current that is typical of TRPV1 activation by exogenous stimuli. Moreover, we specifically demonstrated that 2 pathways downstream of Gq/GPCR signaling, namely endovanilloid production by lipoxygenases and channel phosphorylation by PKC, converge on TRPV1 to evoke a tightly regulated response. Of importance, we show that only when both pathways are acting on TRPV1 is the inflammatory-mediated response achieved. We propose that the requirement of multiple signaling events allows subdued TRPV1 activation to evoke regulated neuronal response during inflammation.-Kumar R., Hazan, A., Geron, M., Steinberg, R., Livni, L., Matzner, H., Priel, A. Activation of transient receptor potential vanilloid 1 by lipoxygenase metabolites depends on PKC phosphorylation.
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Affiliation(s)
- Rakesh Kumar
- Institute for Drug Research, School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adina Hazan
- Institute for Drug Research, School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Matan Geron
- Institute for Drug Research, School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rebbeca Steinberg
- Institute for Drug Research, School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lital Livni
- Institute for Drug Research, School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Henry Matzner
- Institute for Drug Research, School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Avi Priel
- Institute for Drug Research, School of Pharmacy, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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Aghazadeh Tabrizi M, Baraldi PG, Baraldi S, Gessi S, Merighi S, Borea PA. Medicinal Chemistry, Pharmacology, and Clinical Implications of TRPV1 Receptor Antagonists. Med Res Rev 2016; 37:936-983. [PMID: 27976413 DOI: 10.1002/med.21427] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/24/2016] [Accepted: 11/01/2016] [Indexed: 12/28/2022]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is an ion channel expressed on sensory neurons triggering an influx of cations. TRPV1 receptors function as homotetramers responsive to heat, proinflammatory substances, lipoxygenase products, resiniferatoxin, endocannabinoids, protons, and peptide toxins. Its phosphorylation increases sensitivity to both chemical and thermal stimuli, while desensitization involves a calcium-dependent mechanism resulting in receptor dephosphorylation. TRPV1 functions as a sensor of noxious stimuli and may represent a target to avoid pain and injury. TRPV1 activation has been associated to chronic inflammatory pain and peripheral neuropathy. Its expression is also detected in nonneuronal areas such as bladder, lungs, and cochlea where TRPV1 activation is responsible for pathology development of cystitis, asthma, and hearing loss. This review offers a comprehensive overview about TRPV1 receptor in the pathophysiology of chronic pain, epilepsy, cough, bladder disorders, diabetes, obesity, and hearing loss, highlighting how drug development targeting this channel could have a clinical therapeutic potential. Furthermore, it summarizes the advances of medicinal chemistry research leading to the identification of highly selective TRPV1 antagonists and their analysis of structure-activity relationships (SARs) focusing on new strategies to target this channel.
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Affiliation(s)
- Mojgan Aghazadeh Tabrizi
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Pier Giovanni Baraldi
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Stefania Baraldi
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Stefania Gessi
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Stefania Merighi
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Pier Andrea Borea
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara, 44121, Ferrara, Italy
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