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Gualdani R, Barbeau S, Yuan JH, Jacobs DS, Gailly P, Dib-Hajj SD, Waxman SG. TRPV1 corneal neuralgia mutation: Enhanced pH response, bradykinin sensitization, and capsaicin desensitization. Proc Natl Acad Sci U S A 2024; 121:e2406186121. [PMID: 39226353 DOI: 10.1073/pnas.2406186121] [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: 03/26/2024] [Accepted: 07/30/2024] [Indexed: 09/05/2024] Open
Abstract
The factors that contribute to pain after nerve injury remain incompletely understood. Laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) are common surgical techniques to correct refractive errors. After LASIK or PRK, a subset of patients suffers intense and persistent pain, of unknown origin, described by patients as feeling like shards of glass in their eye. Here, we evaluated a TRPV1 variant, p.V527M, found in a 49-y-old woman who developed corneal pain after LASIK and subsequent PRK enhancement, reporting an Ocular Surface Disease Index score of 100. Using patch-clamp and Ca2+ imaging, we found that the V527M mutation enhances the response to acidic pH. Increasing proton concentration induced a stronger leftward shift in the activation curve of V527M compared to WT, resulting in channel activity of the mutant in acidic pH at more physiological membrane potentials. Finally, comparing the responses to consecutive applications of different agonists, we found in V527M channels a reduced capsaicin-induced desensitization and increased sensitization by the arachidonic acid metabolite 12-hydroxyeicosatetraenoic acid (12-HETE). We hypothesize that the increased response in V527M channels to protons and enhanced sensitization by 12-HETE, two inflammatory mediators released in the cornea after tissue damage, may contribute to the pathogenesis of corneal neuralgia after refractive surgery.
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Affiliation(s)
- Roberta Gualdani
- Laboratory of Cell Physiology, Institute of Neuroscience, Université catholique de Louvain, Brussels B-1200, Belgium
| | - Solène Barbeau
- Laboratory of Cell Physiology, Institute of Neuroscience, Université catholique de Louvain, Brussels B-1200, Belgium
| | - Jun-Hui Yuan
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520
- Center for Neuroscience and Regeneration Research, Yale School of Medicine, New Haven, CT 06520
- Neurorehabilitation Research Center, Veterans Affairs Medical Center, West Haven, CT 06516
| | - Deborah S Jacobs
- Department of Ophthalmology, Massachusetts Eye and Ear, Boston, MA 02114
| | - Philippe Gailly
- Laboratory of Cell Physiology, Institute of Neuroscience, Université catholique de Louvain, Brussels B-1200, Belgium
| | - Sulayman D Dib-Hajj
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520
- Center for Neuroscience and Regeneration Research, Yale School of Medicine, New Haven, CT 06520
- Neurorehabilitation Research Center, Veterans Affairs Medical Center, West Haven, CT 06516
| | - Stephen G Waxman
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520
- Center for Neuroscience and Regeneration Research, Yale School of Medicine, New Haven, CT 06520
- Neurorehabilitation Research Center, Veterans Affairs Medical Center, West Haven, CT 06516
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Barr J, Walz A, Restaino AC, Amit M, Barclay SM, Vichaya EG, Spanos WC, Dantzer R, Talbot S, Vermeer PD. Tumor-infiltrating nerves functionally alter brain circuits and modulate behavior in a male mouse model of head-and-neck cancer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.18.562990. [PMID: 37905135 PMCID: PMC10614955 DOI: 10.1101/2023.10.18.562990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Cancer patients often experience changes in mental health, prompting an exploration into whether nerves infiltrating tumors contribute to these alterations by impacting brain functions. Using a male mouse model for head and neck cancer, we utilized neuronal tracing techniques and show that tumor-infiltrating nerves indeed connect to distinct brain areas via the ipsilateral trigeminal ganglion. The activation of this neuronal circuitry led to behavioral alterations represented by decreased nest-building, increased latency to eat a cookie, and reduced wheel running. Tumor-infiltrating nociceptor neurons exhibited heightened activity, as indicated by increased calcium mobilization. Correspondingly, the specific brain regions receiving these neural projections showed elevated cFos and delta FosB expression in tumor-bearing mice, alongside markedly intensified calcium responses compared to non-tumor-bearing counterparts. The genetic elimination of nociceptor neurons in tumor-bearing mice led to decreased brain Fos expression and mitigated the behavioral alterations induced by the presence of the tumor. While analgesic treatment successfully restored behaviors involving oral movements to normalcy in tumor-bearing mice, it did not have a similar therapeutic effect on voluntary wheel running. This discrepancy points towards an intricate relationship, where pain is not the exclusive driver of such behavioral shifts. Unraveling the interaction between the tumor, infiltrating nerves, and the brain is pivotal to developing targeted interventions to alleviate the mental health burdens associated with cancer.
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Maximiano TKE, Carneiro JA, Fattori V, Verri WA. TRPV1: Receptor structure, activation, modulation and role in neuro-immune interactions and pain. Cell Calcium 2024; 119:102870. [PMID: 38531262 DOI: 10.1016/j.ceca.2024.102870] [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: 11/30/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 03/28/2024]
Abstract
In the 1990s, the identification of a non-selective ion channel, especially responsive to capsaicin, revolutionized the studies of somatosensation and pain that were to follow. The TRPV1 channel is expressed mainly in neuronal cells, more specifically, in sensory neurons responsible for the perception of noxious stimuli. However, its presence has also been detected in other non-neuronal cells, such as immune cells, β- pancreatic cells, muscle cells and adipocytes. Activation of the channel occurs in response to a wide range of stimuli, such as noxious heat, low pH, gasses, toxins, endocannabinoids, lipid-derived endovanilloid, and chemical agents, such as capsaicin and resiniferatoxin. This activation results in an influx of cations through the channel pore, especially calcium. Intracellular calcium triggers different responses in sensory neurons. Dephosphorylation of the TRPV1 channel leads to its desensitization, which disrupts its function, while its phosphorylation increases the channel's sensitization and contributes to the channel's rehabilitation after desensitization. Kinases, phosphoinositides, and calmodulin are the main signaling pathways responsible for the channel's regulation. Thus, in this review we provide an overview of TRPV1 discovery, its tissue expression as well as on the mechanisms by which TRPV1 activation (directly or indirectly) induces pain in different disease models.
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Affiliation(s)
- Thaila Kawane Euflazio Maximiano
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil
| | - Jessica Aparecida Carneiro
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil
| | - Victor Fattori
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital-Harvard Medical School, Karp Research Building, 300 Longwood Ave, 02115, Boston, Massachusetts, United States.
| | - Waldiceu A Verri
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil.
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Rohacs T. Phosphoinositide Regulation of TRP Channels: A Functional Overview in the Structural Era. Annu Rev Physiol 2024; 86:329-355. [PMID: 37871124 DOI: 10.1146/annurev-physiol-042022-013956] [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] [Indexed: 10/25/2023]
Abstract
Transient receptor potential (TRP) ion channels have diverse activation mechanisms including physical stimuli, such as high or low temperatures, and a variety of intracellular signaling molecules. Regulation by phosphoinositides and their derivatives is their only known common regulatory feature. For most TRP channels, phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] serves as a cofactor required for activity. Such dependence on PI(4,5)P2 has been demonstrated for members of the TRPM subfamily and for the epithelial TRPV5 and TRPV6 channels. Intracellular TRPML channels show specific activation by PI(3,5)P2. Structural studies uncovered the PI(4,5)P2 and PI(3,5)P2 binding sites for these channels and shed light on the mechanism of channel opening. PI(4,5)P2 regulation of TRPV1-4 as well as some TRPC channels is more complex, involving both positive and negative effects. This review discusses the functional roles of phosphoinositides in TRP channel regulation and molecular insights gained from recent cryo-electron microscopy structures.
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Affiliation(s)
- Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey;
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Amaya-Rodriguez CA, Carvajal-Zamorano K, Bustos D, Alegría-Arcos M, Castillo K. A journey from molecule to physiology and in silico tools for drug discovery targeting the transient receptor potential vanilloid type 1 (TRPV1) channel. Front Pharmacol 2024; 14:1251061. [PMID: 38328578 PMCID: PMC10847257 DOI: 10.3389/fphar.2023.1251061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 12/14/2023] [Indexed: 02/09/2024] Open
Abstract
The heat and capsaicin receptor TRPV1 channel is widely expressed in nerve terminals of dorsal root ganglia (DRGs) and trigeminal ganglia innervating the body and face, respectively, as well as in other tissues and organs including central nervous system. The TRPV1 channel is a versatile receptor that detects harmful heat, pain, and various internal and external ligands. Hence, it operates as a polymodal sensory channel. Many pathological conditions including neuroinflammation, cancer, psychiatric disorders, and pathological pain, are linked to the abnormal functioning of the TRPV1 in peripheral tissues. Intense biomedical research is underway to discover compounds that can modulate the channel and provide pain relief. The molecular mechanisms underlying temperature sensing remain largely unknown, although they are closely linked to pain transduction. Prolonged exposure to capsaicin generates analgesia, hence numerous capsaicin analogs have been developed to discover efficient analgesics for pain relief. The emergence of in silico tools offered significant techniques for molecular modeling and machine learning algorithms to indentify druggable sites in the channel and for repositioning of current drugs aimed at TRPV1. Here we recapitulate the physiological and pathophysiological functions of the TRPV1 channel, including structural models obtained through cryo-EM, pharmacological compounds tested on TRPV1, and the in silico tools for drug discovery and repositioning.
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Affiliation(s)
- Cesar A. Amaya-Rodriguez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Departamento de Fisiología y Comportamiento Animal, Facultad de Ciencias Naturales, Exactas y Tecnología, Universidad de Panamá, Ciudad de Panamá, Panamá
| | - Karina Carvajal-Zamorano
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado Universidad Católica del Maule, Talca, Chile
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca, Chile
| | - Melissa Alegría-Arcos
- Núcleo de Investigación en Data Science, Facultad de Ingeniería y Negocios, Universidad de las Américas, Santiago, Chile
| | - Karen Castillo
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado Universidad Católica del Maule, Talca, Chile
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Birkic N, Visentin D, Svedružić Ž, Reynolds CA. Binding interactions of fatty acyl lipid mediators within the vanilloid pocket of TRPV1: A molecular dynamics study. Prostaglandins Other Lipid Mediat 2023; 169:106771. [PMID: 37657597 PMCID: PMC10841302 DOI: 10.1016/j.prostaglandins.2023.106771] [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: 02/28/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/03/2023]
Abstract
The transient receptor potential vanilloid 1 (TRPV1) channel is a ligand-gated, nonselective cation channel expressed in primary sensory neurons, which has a role in nociception. The channel is activated by noxious heat, pH, capsaicin and other endogenous vanilloids, including lipid mediators (LMs) enzymatically derived from polyunsaturated fatty acids (PUFA). Although capsaicin binding to TRPV1 has been well characterized, the molecular mechanism by which endogenous LM ligands bind the channel is not well understood. In this study, we characterized the binding interactions for 13 endogenous LM ligands, within the vanilloid pocket of TRPV1 using a molecular dynamics (MD) approach. We observed that LM ligands can be grouped based on their structure and affinity for the vanilloid pocket. Furthermore, the position as well as the number of the polar groups on the LM ligand directly impact binding stability through various polar interactions with the protein. As an additional control we performed docking experiments of the PUFA precursor molecules linoleic acid and arachidonic acid which failed to form stable interactions within the vanilloid pocket. While LM ligands with similar structures displayed similar binding interactions, there were notable exceptions in the case of 20-HETE, 9-HODE, and 9,10-DiHOME. Our study offers new insights into the mechanisms involved in TRPV1 activation by endogenous LM ligands. The observed binding interactions may assist in the interpretation of in vivo and in vitro pharmacodynamics studies.
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Affiliation(s)
- Nada Birkic
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
| | - David Visentin
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
| | - Željko Svedružić
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
| | - Christian A Reynolds
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia; Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, MI, USA.
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Petrushenko OA, Stratiievska AO, Petrushenko MO, Lukyanetz EA. Resensitization of TRPV1 channels after the P2 receptor activation in sensory neurons of spinal ganglia in rats. Front Cell Neurosci 2023; 17:1192780. [PMID: 37323583 PMCID: PMC10267357 DOI: 10.3389/fncel.2023.1192780] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
Introduction TRPV1 channels are responsible for detecting noxious stimuli such as heat (>43°C), acid, and capsaicin. P2 receptors are involved in numerous functions of the nervous system, including its modulation and specific response to the application of ATP. In our experiments, we investigated the dynamics of calcium transients in DRG neurons associated with TRPV1 channel desensitization and the effect of activation of P2 receptors on this process. Methods We used DRG neurons from rats P7-8 after 1-2 days of culture to measure calcium transients by microfluorescence calcimetry using the fluorescent dye Fura-2 AM. Results We have shown that DRG neurons of small (d < 22 μm) and medium (d = 24-35 μm) sizes differ in TRPV1 expression. Thus, TRPV1 channels are mainly present in small nociceptive neurons (59% of the studied neurons). Short-term sequential application of the TRPV1 channel agonist capsaicin (100nM) leads to the desensitization of TRPV1 channels by the type of tachyphylaxis. We identified three types of sensory neurons based on responses to capsaicin: (1) desensitized 37.5%, (2) non-desensitized 34.4%, and (3) insensitive 23.4% to capsaicin. It has also been shown that P2 receptors are present in all types of neurons according to their size. So, the responses to ATP were different in different-sized neurons. Applying ATP (0.1 mM) to the intact cell membrane after the onset of tachyphylaxis caused recovery of calcium transients in response to the addition of capsaicin in these neurons. The amplitude of the capsaicin response after reconstitution with ATP was 161% of the previous minimal calcium transient in response to capsaicin. Discussion Significantly, the restoration of the amplitude of calcium transients under the ATP application is not associated with changes in the cytoplasmic pool of ATP because this molecule does not cross the intact cell membrane, thus, our results show the interaction between TRPV1 channels and P2 receptors. It is important to note that the restoration of the amplitude of calcium transients through TRPV1 channels after application of ATP was observed mainly in cells of 1-2 days of cultivation. Thus, the resensitization of capsaicin transients following P2 receptor activation may be associated with the regulation of the sensitivity of sensory neurons.
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Lu C, Liu Q, Deng M, Liao H, Yang X, Ma P. Interaction of high temperature and NO 2 exposure on asthma risk: In vivo experimental evidence of inflammation and oxidative stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161760. [PMID: 36702287 DOI: 10.1016/j.scitotenv.2023.161760] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Allergic asthma is a complicated respiratory disease with many concerns. Mounting epidemiological evidence linked temperature (T) and NO2 with allergic asthma, yet toxicological studies remain scarce. We conducted an in vivo study to explore toxicological evidence in T-NO2 interaction on allergic asthma, to investigate underlying toxicological mechanisms. 90 male Balb/c mice were randomly and equally divided into 6 groups including saline control, ovalbumin (OVA)-sensitized, OVA + 35 °C, OVA + NO2, OVA + 35 °C + NO2, and OVA + 35 °C + NO2 + capsazepine (CZP), adopting treatment for 38 days. We measured pulmonary functions of inspiratory resistance (Ri), expiratory resistance (Re) and airway compliance (Cldyn), serum protein biomarkers, indexes of pulmonary inflammation, histopathological changes and protective effects of CZP. Airway hyperresponsiveness (AHR) was aggravated by high T (35 °C) and NO2 (5 ppm) co-exposure with a series of aggravating asthmatic symptoms including airway wall thickening, lumen stenosis, goblet cell proliferation, mucus hypersecretion, and subepithelial fibrotic hyperplasia, providing evidence in the toxicological impact of high T-NO2 interaction. The biomarkers of serum immune functions (Total-IgE, OVA-sIgE and IL-4), pro-inflammation (IL-6 and TNF-α), oxidative stress cytokines (8-OHdG, ROS and MDA), airway resistance (Ri and Re), and TRPV1 expression significantly increased, while IFN-γ, GSH and airway compliance (Cldyn) significantly decreased with co-exposure to high T and NO2. We observed that CZP addition significantly ameliorated these toxicological effects and biomarker levels induced by heat-NO2 interaction. Our results suggest a toxicity of heat-NO2 interaction on asthma with clear mechanisms, which can be ameliorated by CZP, indicating that both oxidative stress and TRPV1 expression may be primarily responsible for asthma of heat-NO2-induced toxicity.
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Affiliation(s)
- Chan Lu
- XiangYa School of Public Health, Central South University, Changsha 410078, China.
| | - Qin Liu
- XiangYa School of Public Health, Central South University, Changsha 410078, China
| | - Miaomiao Deng
- XiangYa School of Public Health, Central South University, Changsha 410078, China
| | - Hongsen Liao
- XiangYa School of Public Health, Central South University, Changsha 410078, China
| | - Xu Yang
- School of Public Health, Hubei University of Science and Technology, Xianning 437100, China
| | - Ping Ma
- School of Public Health, Hubei University of Science and Technology, Xianning 437100, China
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Chen X, Lu W, Lu C, Zhang L, Xu F, Dong H. The CaSR/TRPV4 coupling mediates pro-inflammatory macrophage function. Acta Physiol (Oxf) 2023; 237:e13926. [PMID: 36606511 DOI: 10.1111/apha.13926] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 12/29/2022] [Accepted: 01/02/2023] [Indexed: 01/07/2023]
Abstract
AIM Although calcium-sensing receptor (CaSR) and transient receptor potential vanilloid 4 (TRPV4) channels are functionally expressed on macrophages, it is unclear if they work coordinately to mediate macrophage function. The present study investigates whether CaSR couples to TRPV4 channels and mediates macrophage polarization via Ca2+ signaling. METHODS The role of CaSR/TRPV4/Ca2+ signaling was assessed in lipopolysaccharide (LPS)-treated peritoneal macrophages (PMs) from wild-type (WT) and TRPV4 knockout (TRPV4 KO) mice. The expression and function of CaSR and TRPV4 in PMs were analyzed by immunofluorescence and digital Ca2+ imaging. The correlation factors of M1 polarization, CCR7, IL-1β, and TNFα were detected using q-PCR, western blot, and ELISA. RESULTS We found that PMs expressed CaSR and TRPV4, and CaSR activation-induced marked Ca2+ signaling predominately through extracellular Ca2+ entry, which was inhibited by selective pharmacological blockers of CaSR and TRPV4 channels. The CaSR activation-induced Ca2+ signaling was significantly attenuated in PMs from TRPV4 KO mice compared to those from WT mice. Moreover, the CaSR activation-induced Ca2+ entry via TRPV4 channels was inhibited by blocking phospholipases A2 (PLA2)/cytochromeP450 (CYP450) and phospholipase C (PLC)/Protein kinase C (PKC) pathways. Finally, CaSR activation promoted the expression and release of M1-associated cytokines IL-1β and TNFɑ, which were attenuated in PMs from TRPV4 KO mice. CONCLUSION We reveal a novel coupling of the CaSR and TRPV4 channels via PLA2/CYP450 and PLC/PKC pathways, promoting a Ca2+ -dependent M1 macrophage polarization. Modulation of this coupling and downstream pathways may become a potential strategy for the prevention/treatment of immune-related disease.
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Affiliation(s)
- Xiongying Chen
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Wei Lu
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China
| | - Cheng Lu
- Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Luyun Zhang
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Feng Xu
- Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Hui Dong
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China
- Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
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TRPV1 is involved in abdominal hyperalgesia in a mouse model of lipopolysaccharide-induced peritonitis and influences the immune response via peripheral noradrenergic neurons. Life Sci 2023; 317:121472. [PMID: 36750138 DOI: 10.1016/j.lfs.2023.121472] [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: 08/28/2022] [Revised: 01/12/2023] [Accepted: 01/30/2023] [Indexed: 02/07/2023]
Abstract
AIMS The transient receptor potential vanilloid subfamily 1 (TRPV1) not only plays a role as a nociceptor but also has some regulatory effects on the immune system. We investigated the effects of TRPV1 on abdominal pain and the immune system in lipopolysaccharide (LPS)-induced peritonitis and the association between TRPV1 and peripheral noradrenergic neurons. MAIN METHODS Experiments were performed in 8- to 14-week-old male wild-type (WT) and TRPV1 knockout (KO) mice. The mice were intraperitoneally injected with a non-lethal dose of LPS. Pain assessment and investigation of changes in the immune system were performed. Denervation of sympathetic nerves and the noradrenergic splenic nerve was induced by intraperitoneal administration of 6-hydroxydopamine. KEY FINDINGS The levels of serum cytokines were not significantly different in WT mice and TRPV1 KO mice. Abdominal mechanical hyperalgesia was greater in WT mice than in TRPV1 KO mice from 6 h to 3 days. The numbers of macrophages, neutrophils, dendritic cells, and CD4 T cells in the spleens of TRPV1 KO mice were significantly increased compared to those in WT mice 4 days after LPS administration. By noradrenergic denervation, the numbers of those cells in WT mice increased to levels comparable to those in TRPV1 KO mice. SIGNIFICANCE In LPS-induced peritonitis, abdominal inflammatory pain was transmitted via TRPV1. In addition, TRPV1 had an anti-inflammatory effect on the spleen in the late phase of peritonitis. This anti-inflammatory effect was thought to be mediated by activation of the sympathetic nervous system and/or noradrenergic splenic nerve induced by TRPV1 activation.
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11
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Millet A, Jendzjowsky N. Pathogen recognition by sensory neurons: hypotheses on the specificity of sensory neuron signaling. Front Immunol 2023; 14:1184000. [PMID: 37207232 PMCID: PMC10189129 DOI: 10.3389/fimmu.2023.1184000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 04/19/2023] [Indexed: 05/21/2023] Open
Abstract
Sensory neurons cooperate with barrier tissues and resident immune cells to form a significant aspect of defensive strategies in concert with the immune system. This assembly of neuroimmune cellular units is exemplified across evolution from early metazoans to mammalian life. As such, sensory neurons possess the capability to detect pathogenic infiltrates at barrier surfaces. This capacity relies on mechanisms that unleash specific cell signaling, trafficking and defensive reflexes. These pathways exploit mechanisms to amplify and enhance the alerting response should pathogenic infiltration seep into other tissue compartments and/or systemic circulation. Here we explore two hypotheses: 1) that sensory neurons' potential cellular signaling pathways require the interaction of pathogen recognition receptors and ion channels specific to sensory neurons and; 2) mechanisms which amplify these sensing pathways require activation of multiple sensory neuron sites. Where possible, we provide references to other apt reviews which provide the reader more detail on specific aspects of the perspectives provided here.
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Affiliation(s)
- Antoine Millet
- Respiratory & Exercise Physiology, The Lundquist Institute for Biomedical Innovation at Harbor University of California Los Angeles (UCLA) Medical Center, Torrance, CA, United States
| | - Nicholas Jendzjowsky
- Respiratory & Exercise Physiology, The Lundquist Institute for Biomedical Innovation at Harbor University of California Los Angeles (UCLA) Medical Center, Torrance, CA, United States
- Division of Respiratory and Critical Care Medicine and Physiology, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States
- *Correspondence: Nicholas Jendzjowsky,
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Spekker E, Körtési T, Vécsei L. TRP Channels: Recent Development in Translational Research and Potential Therapeutic Targets in Migraine. Int J Mol Sci 2022; 24:ijms24010700. [PMID: 36614146 PMCID: PMC9820749 DOI: 10.3390/ijms24010700] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/22/2022] [Accepted: 12/29/2022] [Indexed: 01/03/2023] Open
Abstract
Migraine is a chronic neurological disorder that affects approximately 12% of the population. The cause of migraine headaches is not yet known, however, when the trigeminal system is activated, neuropeptides such as calcitonin gene-related peptide (CGRP) and substance P (SP) are released, which cause neurogenic inflammation and sensitization. Advances in the understanding of migraine pathophysiology have identified new potential pharmacological targets. In recent years, transient receptor potential (TRP) channels have been the focus of attention in the pathophysiology of various pain disorders, including primary headaches. Genetic and pharmacological data suggest the role of TRP channels in pain sensation and the activation and sensitization of dural afferents. In addition, TRP channels are widely expressed in the trigeminal system and brain regions which are associated with the pathophysiology of migraine and furthermore, co-localize several neuropeptides that are implicated in the development of migraine attacks. Moreover, there are several migraine trigger agents known to activate TRP channels. Based on these, TRP channels have an essential role in migraine pain and associated symptoms, such as hyperalgesia and allodynia. In this review, we discuss the role of the certain TRP channels in migraine pathophysiology and their therapeutic applicability.
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Affiliation(s)
- Eleonóra Spekker
- ELKH-SZTE Neuroscience Research Group, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
| | - Tamás Körtési
- ELKH-SZTE Neuroscience Research Group, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
- Faculty of Health Sciences and Social Studies, University of Szeged, Temesvári krt. 31, H-6726 Szeged, Hungary
| | - László Vécsei
- ELKH-SZTE Neuroscience Research Group, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
- Correspondence: ; Tel.: +36-62-545351; Fax: +36-62-545597
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13
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Robilotto GL, Mohapatra DP, Shepherd AJ, Mickle AD. Role of Src kinase in regulating protein kinase C mediated phosphorylation of TRPV1. Eur J Pain 2022; 26:1967-1978. [PMID: 35900227 PMCID: PMC9483845 DOI: 10.1002/ejp.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 06/19/2022] [Accepted: 07/23/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Transient receptor potential vanilloid-1 (TRPV1), activated by heat, acidic pH, endogenous vanilloids and capsaicin, is essential for thermal hyperalgesia. Under inflammatory conditions, phosphorylation of TRPV1 by protein kinase C (PKC) can sensitize the channel and decrease the activation threshold. Src kinase also phosphorylates TRPV1, promoting channel trafficking to the plasma membrane. These post-translational modifications are important for several chronic pain conditions. This study presents a previously undescribed relationship between Src and PKC phosphorylation of TRPV1, influencing the thermal hypersensitivity associated with TRPV1 activation. METHODS We assessed TRPV1 channel activity using intracellular calcium imaging and patch-clamp electrophysiology in mouse dorsal root ganglion cultures. Additionally, we used behavioural experiments to evaluate plantar thermal sensitivity following intraplantar injections of activators of known modulators of TRPV1 with and without an Src antagonist. RESULTS Using calcium imaging and patch-clamp techniques, we demonstrated that pharmacological inhibition of Src kinase or mutation of the Src phosphorylation site on TRPV1 prevented PKC but not PKA-mediated sensitization of TRPV1 in vitro. We found that intraplantar injection of the PKC activator phorbol 12-myristate 13-acetate (PMA) or bradykinin produces thermal hypersensitivity that can be attenuated by pharmacological inhibition of Src. Additionally, complete Freund's Adjuvant (CFA)-induced inflammatory hypersensitivity could also be attenuated by local Src kinase inhibition. CONCLUSIONS Our data demonstrate that Src phosphorylation is critical for PKC-mediated sensitization of TRPV1. Further, in a model of inflammatory pain, CFA, Src kinase inhibition could reduce thermal hypersensitivity. Targeting of Src kinase may have analgesic benefits in inflammatory pain conditions. SIGNIFICANCE Src kinase-mediated phosphorylation of TRPV1 is a critical regulator of the PKC-induced sensitization induced by multiple inflammatory mediators. This suggest a new regulatory mechanism governing TRPV1 function and a potential therapeutic target for inflammatory type pain, including cancer pain where Src antagonists are currently utilized.
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Affiliation(s)
- Gabriella L. Robilotto
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida
| | - Durga P. Mohapatra
- Department of Pharmacology, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, 52242
- Anesthesia, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, 52242
| | - Andrew J. Shepherd
- Department of Pharmacology, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, 52242
- Department of Symptom Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030
| | - Aaron D. Mickle
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida
- Department of Pharmacology, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, 52242
- J. Crayton Pruitt Family Department of Biomedical Engineering, College of Engineering, University of Florida
- Department of Neuroscience, College of Medicine, University of Florida
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14
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Kashio M, Masubuchi S, Tominaga M. Protein kinase C-mediated phosphorylation of transient receptor potential melastatin type 2 Thr738 counteracts the effect of cytosolic Ca 2+ and elevates the temperature threshold. J Physiol 2022; 600:4287-4302. [PMID: 36042566 PMCID: PMC9826287 DOI: 10.1113/jp283350] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/26/2022] [Indexed: 01/11/2023] Open
Abstract
The transient receptor potential melastatin type 2 (TRPM2) channel is a non-selective cation channel that has high Ca2+ permeability. TRPM2 is sensitive to warm temperatures and is expressed in cells and tissues that are maintained at core body temperature. TRPM2 activity is also regulated by endogenous factors including redox signalling, cytosolic Ca2+ and adenosine diphosphate ribose. As a result of its wide expression and function at core body temperature, these endogenous factors could regulate TRPM2 activity at body temperature under physiological and pathophysiological conditions. We previously reported that cellular redox signalling can lower TRPM2 temperature thresholds, although the mechanism that regulates these thresholds is unclear. Here, we used biochemical and electrophysiological techniques to explore another regulatory mechanism for TRPM2 temperature thresholds that is mediated by TRPM2 phosphorylation. Our results show that: (1) the temperature threshold for TRPM2 activation is lowered by cytosolic Ca2+ ; (2) protein kinase C-mediated phosphorylation of TRPM2 counteracts the effect of cytosolic Ca2+ ; and (3) Thr738 in mouse TRPM2 that lies near the Ca2+ binding site in the cytosolic cleft of the transmembrane domain is a potential phosphorylation site that may be involved in phosphorylation-mediated elevation of TRPM2 thresholds. These findings provide structure-based evidence to understand how temperature thresholds of thermo-sensitive TRP channels (thermo-TRPs) are determined and regulated. KEY POINTS: The transient receptor potential melastatin type 2 (TRPM2) ion channel is temperature-sensitive and Ca2+ -permeable. Endogenous factors and pathways such as redox signalling can regulate TRPM2 activity at body temperature under physiological and pathophysiological conditions. In the present study, we report the novel finding that cytosolic Ca2+ lowers the temperature threshold for TRPM2 activation in a concentration-dependent manner. Protein kinase C-mediated phosphorylation of TRPM2 at amino acid Thr782 elevates the temperature threshold for activation by counteracting the effects of cytosolic Ca2+ . These findings provide structure-based evidence to understand how temperature thresholds of thermo-sensitive TRP channels are determined and regulated.
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Affiliation(s)
- Makiko Kashio
- Division of Cell SignalingNational Institute for Physiological SciencesNational Institutes for Natural SciencesOkazakiAichiJapan
| | - Satoru Masubuchi
- Department of PhysiologyAichi Medical UniversityNagakuteAichiJapan
| | - Makoto Tominaga
- Division of Cell SignalingNational Institute for Physiological SciencesNational Institutes for Natural SciencesOkazakiAichiJapan,Thermal Biology GroupExploratory Research Center on Life and Living Systems (ExCELLS)National Institutes of Natural SciencesOkazakiAichiJapan
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15
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Asiedu K. Role of ocular surface neurobiology in neuronal-mediated inflammation in dry eye disease. Neuropeptides 2022; 95:102266. [PMID: 35728484 DOI: 10.1016/j.npep.2022.102266] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 01/18/2023]
Abstract
Inflammation is the consequence of dry eye disease regardless of its etiology. Several injurious or harmless processes to the ocular surface neurons promote ocular surface neurogenic inflammation, leading to the vicious cycle of dry eye disease. These processes include the regular release of neuromediators during the conduction of ocular surface sensations, hyperosmolarity-induced ocular surface neuronal damage, neuro-regenerative activities, and neuronal-mediated dendritic cell activities. Neurogenic inflammation appears to be the main culprit, instigating the self-perpetuating inflammation observed in patients with dry eye disease.
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Affiliation(s)
- Kofi Asiedu
- School of Optometry & Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, Australia.
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16
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Jennings EM, Sullivan LC, Jamshidi RJ, LoCoco PM, Smith HR, Chavera TS, Berg KA, Clarke WP. Age-related changes in peripheral nociceptor function. Neuropharmacology 2022; 216:109187. [PMID: 35835212 DOI: 10.1016/j.neuropharm.2022.109187] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 06/21/2022] [Accepted: 07/03/2022] [Indexed: 01/05/2023]
Abstract
Pain and pain management in the elderly population is a significant social and medical problem. Pain sensation is a complex phenomenon that typically involves activation of peripheral pain-sensing neurons (nociceptors) which send signals to the spinal cord and brain that are interpreted as pain, an unpleasant sensory experience. In this work, young (4-5 months) and aged (26-27 months) Fischer 344 x Brown Norway (F344xBN) rats were examined for nociceptor sensitivity to activation by thermal (cold and heat) and mechanical stimulation following treatment with inflammatory mediators and activators of transient receptor potential (TRP) channels. Unlike other senses that decrease in sensitivity with age, sensitivity of hindpaw nociceptors to thermal and mechanical stimulation was not different between young and aged F344xBN rats. Intraplantar injection of bradykinin (BK) produced greater thermal and mechanical allodynia in aged versus young rats, whereas only mechanical allodynia was greater in aged rats following injection of prostaglandin E2 (PGE2). Intraplantar injection of TRP channel activators, capsaicin (TRPV1), mustard oil (TRPA1) and menthol (TRPM8) each resulted in greater mechanical allodynia in aged versus young rats and capsaicin-induced heat allodynia was also greater in aged rats. A treatment-induced allodynia that was greater in young rats was never observed. The anti-allodynic effects of intraplantar injection of kappa and delta opioid receptor agonists, salvinorin-A and D-Pen2,D-Pen5]enkephalin (DPDPE), respectively, were greater in aged than young rats, whereas mu opioid receptor agonists, [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) and morphine, were not effective in aged rats. Consistent with these observations, in primary cultures of peripheral sensory neurons, inhibition of cAMP signaling in response to delta and kappa receptor agonists was greater in cultures derived from aged rats. By contrast, mu receptor agonists did not inhibit cAMP signaling in aged rats. Thus, age-related changes in nociceptors generally favor increased pain signaling in aged versus young rats, suggesting that changes in nociceptor sensitivity may play a role in the increased incidence of pain in the elderly population. These results also suggest that development of peripherally-restricted kappa or delta opioid receptor agonists may provide safer and effective pain relief for the elderly.
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Affiliation(s)
- Elaine M Jennings
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Laura C Sullivan
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Raehannah J Jamshidi
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Peter M LoCoco
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Hudson R Smith
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Teresa S Chavera
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Kelly A Berg
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - William P Clarke
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA.
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17
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Kazandzhieva K, Mammadova-Bach E, Dietrich A, Gudermann T, Braun A. TRP channel function in platelets and megakaryocytes: basic mechanisms and pathophysiological impact. Pharmacol Ther 2022; 237:108164. [PMID: 35247518 DOI: 10.1016/j.pharmthera.2022.108164] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/29/2022] [Accepted: 02/28/2022] [Indexed: 12/30/2022]
Abstract
Transient receptor potential (TRP) proteins form a superfamily of cation channels that are expressed in a wide range of tissues and cell types. During the last years, great progress has been made in understanding the molecular complexity and the functions of TRP channels in diverse cellular processes, including cell proliferation, migration, adhesion and activation. The diversity of functions depends on multiple regulatory mechanisms by which TRP channels regulate Ca2+ entry mechanisms and intracellular Ca2+ dynamics, either through membrane depolarization involving cation influx or store- and receptor-operated mechanisms. Abnormal function or expression of TRP channels results in vascular pathologies, including hypertension, ischemic stroke and inflammatory disorders through effects on vascular cells, including the components of blood vessels and platelets. Moreover, some TRP family members also regulate megakaryopoiesis and platelet production, indicating a complex role of TRP channels in pathophysiological conditions. In this review, we describe potential roles of TRP channels in megakaryocytes and platelets, as well as their contribution to diseases such as thrombocytopenia, thrombosis and stroke. We also critically discuss the potential of TRP channels as possible targets for disease prevention and treatment.
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Affiliation(s)
- Kalina Kazandzhieva
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Elmina Mammadova-Bach
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany; Division of Nephrology, Department of Medicine IV, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Alexander Dietrich
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany; German Center for Lung Research (DZL), Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany; German Center for Lung Research (DZL), Munich, Germany.
| | - Attila Braun
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany.
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18
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PKC regulation of ion channels: The involvement of PIP 2. J Biol Chem 2022; 298:102035. [PMID: 35588786 PMCID: PMC9198471 DOI: 10.1016/j.jbc.2022.102035] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 11/24/2022] Open
Abstract
Ion channels are integral membrane proteins whose gating has been increasingly shown to depend on the presence of the low-abundance membrane phospholipid, phosphatidylinositol (4,5) bisphosphate. The expression and function of ion channels is tightly regulated via protein phosphorylation by specific kinases, including various PKC isoforms. Several channels have further been shown to be regulated by PKC through altered surface expression, probability of channel opening, shifts in voltage dependence of their activation, or changes in inactivation or desensitization. In this review, we survey the impact of phosphorylation of various ion channels by PKC isoforms and examine the dependence of phosphorylated ion channels on phosphatidylinositol (4,5) bisphosphate as a mechanistic endpoint to control channel gating.
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19
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Saha S, Mohanta S, Das R, Dalai R, Divyanshi, Tiwari N, Tiwari A, Kumar A, Goswami C. Ratio of Hydrophobic-Hydrophilic and Positive-Negative Residues at Lipid-Water-Interface Influences Surface Expression and Channel Gating of TRPV1. J Membr Biol 2022; 255:319-339. [PMID: 35608627 DOI: 10.1007/s00232-022-00243-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/03/2022] [Indexed: 12/19/2022]
Abstract
During evolution, TRPV1 has lost, retained or selected certain residues at Lipid-Water-Interface (LWI) and formed specific patterns there. The ratio of "hydrophobic-hydrophilic" and "positive-negative-charged" residues at the inner LWI remains conserved throughout vertebrate evolution and plays important role in regulating TRPV1 trafficking and localization. Arg575 is an important residue as Arg575Asp mutant has reduced surface expression, co-localization with lipid raft markers, cell area and increased cell lethality. This lethality is most likely due to the disruption of the ratio between positive-negative charges caused by the mutation. Such lethality can be rescued by either using TRPV1-specfic inhibitor 5'-IRTX or by restoring the positive-negative charge ratio at that position, i.e. by introducing Asp576Arg mutation in Arg575Asp backbone. We propose that Arg575Asp mutation confers TRPV1 in a "constitutive-open-like" condition. These findings have broader implication in understanding the molecular evolution of thermo-sensitive ion channels and the micro-environments involved in processes that goes erratic in different diseases. The segment of TRPV1 that is present at the inner lipid-water-interface (LWI) has a specific pattern of amino acid combinations. The overall ratio of +ve charge /-ve charge and the ratio of hydrophobicity/hydrophilicity remain constant throughout the vertebrate evolution (ca 450 million years). This specific pattern is not observed in the outer LWI region of TRPV1.
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Affiliation(s)
- Somdatta Saha
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Sushama Mohanta
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Rashmita Das
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Ritesh Dalai
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Divyanshi
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Nikhil Tiwari
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Ankit Tiwari
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India
| | - Abhishek Kumar
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India
| | - Chandan Goswami
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India. .,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India.
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20
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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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21
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Reyes-García J, Carbajal-García A, Montaño LM. Transient receptor potential cation channel subfamily V (TRPV) and its importance in asthma. Eur J Pharmacol 2022; 915:174692. [PMID: 34890545 DOI: 10.1016/j.ejphar.2021.174692] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 12/18/2022]
Abstract
Transient receptor potential (TRP) ion channels play critical roles in physiological and pathological conditions. Increasing evidence has unveiled the contribution of TRP vanilloid (TRPV) family in the development of asthma. The TRPV family is a group (TRPV1-TRPV6) of polymodal channels capable of sensing thermal, acidic, mechanical stress, and osmotic stimuli. TRPVs can be activated by endogenous ligands including, arachidonic acid derivatives or endocannabinoids. While TRPV1-TRPV4 are non-selective cation channels showing a predominance for Ca2+ over Na + influx, TRPV5 and TRPV6 are only Ca2+ permeable selective channels. Asthma is a chronic inflammatory bronchopulmonary disorder involving airway hyperresponsiveness (AHR) and airway remodeling. Patients suffering from allergic asthma display an inflammatory pattern driven by cytokines produced in type-2 helper T cells (Th2) and type 2 innate lymphoid cells (ILC2s). Ion channels are essential regulators in airway smooth muscle (ASM) and immune cells physiology. In this review, we summarize the contribution of TRPV1, TRPV2, and TRPV4 to the pathogenesis of asthma. TRPV1 is associated with hypersensitivity to environmental pollutants and chronic cough, inflammation, AHR, and remodeling. TRPV2 is increased in peripheral lymphocytes of asthmatic patients. TRPV4 contributes to ASM cells proliferation, and its blockade leads to a reduced eosinophilia, neutrophilia, as well as an abolished AHR. In conclusion, TRPV2 may represent a novel biomarker for asthma in children; meanwhile, TRPV1 and TRPV4 seem to be essential contributors to the development and exacerbations of asthma. Moreover, these channels may serve as novel therapeutic targets for this ailment.
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Affiliation(s)
- Jorge Reyes-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, México.
| | - Abril Carbajal-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, México.
| | - Luis M Montaño
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, México.
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22
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Phan TX, Ton HT, Gulyás H, Pórszász R, Tóth A, Russo R, Kay MW, Sahibzada N, Ahern GP. TRPV1 in arteries enables a rapid myogenic tone. J Physiol 2022; 600:1651-1666. [PMID: 35020949 PMCID: PMC8976781 DOI: 10.1113/jp281873] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/11/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We explored the physiological role of TRPV1 in vascular smooth muscle. TRPV1 antagonists dilated skeletal muscle arterioles both ex vivo and in vivo, increased coronary perfusion and decreased systemic blood pressure. Stretch of arteriolar myocytes and increases in intraluminal pressure in arteries triggered rapid Ca2+ signaling and vasoconstriction respectively. Pharmacologic and/or genetic disruption of TRPV1 significantly inhibited the magnitude and rate of these responses. Furthermore, disrupting TRPV1 blunted the rapid vasodilation evoked by arterial constriction. Pharmacological experiments identified key roles for phospholipase C and protein kinase C, combined with temperature, in TRPV1-dependent arterial tone. These results show that TRPV1 in arteriolar myocytes dynamically regulates myogenic tone and blood flow in the heart and skeletal muscle. ABSTRACT Arterioles maintain blow flow by adjusting their diameter in response to changes in local blood pressure. In this process called the myogenic response, a vascular smooth muscle mechanosensor controls tone predominantly through altering the membrane potential. In general, myogenic responses occur slowly (minutes). In the heart and skeletal muscle, however, tone is activated rapidly (tens of seconds) and terminated by brief (100 ms) arterial constrictions. Previously, we identified extensive expression of TRPV1 in the smooth muscle of arterioles supplying skeletal muscle, heart and fat. Here we reveal a critical role for TRPV1 in the rapid myogenic tone of these tissues. TRPV1 antagonists dilated skeletal muscle arterioles in vitro and in vivo, increased coronary flow in isolated hearts, and transiently decreased blood pressure. All of these pharmacologic effects were abolished by genetic disruption of TRPV1. Stretch of isolated vascular smooth muscle cells or raised intravascular pressure in arteries triggered Ca2+ signaling and vasoconstriction. The majority of these stretch-responses were TRPV1-mediated, with the remaining tone being inhibited by the TRPM4 antagonist, 9-phenantrol. Notably, tone developed more quickly in arteries from wild-type compared with TRPV1-null mice. Furthermore, the immediate vasodilation following brief constriction of arterioles depended on TRPV1, consistent with a rapid deactivation of TRPV1. Pharmacologic experiments revealed that membrane stretch activates phospholipase C/protein kinase C signaling combined with heat to activate TRPV1, and in turn, L-type Ca2+ channels. These results suggest a critical role, for TRPV1 in the dynamic regulation of myogenic tone and blood flow in the heart and skeletal muscle. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Thieu X Phan
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, USA.,Department of Biology, Vinh University, Vinh City, Vietnam
| | - Hoai T Ton
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, USA.,Department of Biology, Vinh University, Vinh City, Vietnam
| | - Hajnalka Gulyás
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Doctoral School of Pharmaceutical Sciences, Debrecen, Hungary
| | - Róbert Pórszász
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Doctoral School of Pharmaceutical Sciences, Debrecen, Hungary
| | - Attila Tóth
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Rebekah Russo
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Matthew W Kay
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Niaz Sahibzada
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, USA
| | - Gerard P Ahern
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, USA
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23
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Duitama M, Moreno Y, Santander SP, Casas Z, Sutachan JJ, Torres YP, Albarracín SL. TRP Channels as Molecular Targets to Relieve Cancer Pain. Biomolecules 2021; 12:1. [PMID: 35053150 PMCID: PMC8774023 DOI: 10.3390/biom12010001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/17/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022] Open
Abstract
Transient receptor potential (TRP) channels are critical receptors in the transduction of nociceptive stimuli. The microenvironment of diverse types of cancer releases substances, including growth factors, neurotransmitters, and inflammatory mediators, which modulate the activity of TRPs through the regulation of intracellular signaling pathways. The modulation of TRP channels is associated with the peripheral sensitization observed in patients with cancer, which results in mild noxious sensory stimuli being perceived as hyperalgesia and allodynia. Secondary metabolites derived from plant extracts can induce the activation, blocking, and desensitization of TRP channels. Thus, these compounds could act as potential therapeutic agents, as their antinociceptive properties could be beneficial in relieving cancer-derived pain. In this review, we will summarize the role of TRPV1 and TRPA1 in pain associated with cancer and discuss molecules that have been reported to modulate these channels, focusing particularly on the mechanisms of channel activation associated with molecules released in the tumor microenvironment.
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Affiliation(s)
- Milena Duitama
- Departamento de Nutrición y Bioquímica, Pontificia Universidad Javeriana, Bogotá 110231, Colombia; (M.D.); (Z.C.); (J.J.S.)
| | - Yurany Moreno
- Department of Lymphoma & Myeloma, MD Anderson Cancer Center, The University of Texas, Houston, TX 77030, USA;
| | - Sandra Paola Santander
- Phytoimmunomodulation Research Group, Juan N. Corpas University Foundation, Bogotá 111111, Colombia;
| | - Zulma Casas
- Departamento de Nutrición y Bioquímica, Pontificia Universidad Javeriana, Bogotá 110231, Colombia; (M.D.); (Z.C.); (J.J.S.)
| | - Jhon Jairo Sutachan
- Departamento de Nutrición y Bioquímica, Pontificia Universidad Javeriana, Bogotá 110231, Colombia; (M.D.); (Z.C.); (J.J.S.)
| | - Yolima P. Torres
- Departamento de Nutrición y Bioquímica, Pontificia Universidad Javeriana, Bogotá 110231, Colombia; (M.D.); (Z.C.); (J.J.S.)
| | - Sonia L. Albarracín
- Departamento de Nutrición y Bioquímica, Pontificia Universidad Javeriana, Bogotá 110231, Colombia; (M.D.); (Z.C.); (J.J.S.)
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Long W, Johnson J, Kalyaanamoorthy S, Light P. TRPV1 channels as a newly identified target for vitamin D. Channels (Austin) 2021; 15:360-374. [PMID: 33825665 PMCID: PMC8032246 DOI: 10.1080/19336950.2021.1905248] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/15/2021] [Accepted: 03/15/2021] [Indexed: 11/23/2022] Open
Abstract
Vitamin D is known to elicit many biological effects in diverse tissue types and is thought to act almost exclusively upon its canonical receptor within the nucleus, leading to gene transcriptional changes and the subsequent cellular response. However, not all the observed effects of vitamin D can be attributed to this sole mechanism, and other cellular targets likely exist but remain to be identified. Our recent discovery that vitamin D is a partial agonist of the Transient Receptor Potential Vanilloid family 1 (TRPV1) channel may provide new insights as to how this important vitamin exerts its biological effects either independently or in addition to the nuclear vitamin D receptor. In this review, we discuss the literature surrounding this apparent discrepancy in vitamin D signaling and compare vitamin D with known TRPV1 ligands with respect to their binding to TRPV1. Furthermore, we provide evidence supporting the notion that this novel vitamin D/TRPV1 axis may explain some of the beneficial actions of this vitamin in disease states where TRPV1 expression and vitamin D deficiency are known to overlap. Finally, we discuss whether vitamin D may also act on other members of the TRP family of ion channels.
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Affiliation(s)
- Wentong Long
- Department of Pharmacology and the Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Janyne Johnson
- Department of Pharmacology and the Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | | | - Peter Light
- Department of Pharmacology and the Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
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25
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Activation of PKCε-ALDH2 Axis Prevents 4-HNE-Induced Pain in Mice. Biomolecules 2021; 11:biom11121798. [PMID: 34944441 PMCID: PMC8698646 DOI: 10.3390/biom11121798] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 01/28/2023] Open
Abstract
Protein kinase Cε (PKCε) is highly expressed in nociceptor neurons and its activation has been reported as pro-nociceptive. Intriguingly, we previously demonstrated that activation of the mitochondrial PKCε substrate aldehyde dehydrogenase-2 (ALDH2) results in anti-nociceptive effects. ALDH2 is a major enzyme responsible for the clearance of 4-hydroxy-2-nonenal (4-HNE), an oxidative stress byproduct accumulated in inflammatory conditions and sufficient to induce pain hypersensitivity in rodents. Here we determined the contribution of the PKCε-ALDH2 axis during 4-HNE-induced mechanical hypersensitivity. Using knockout mice, we demonstrated that PKCε is essential for the nociception recovery during 4-HNE-induced hypersensitivity. We also found that ALDH2 deficient knockin mice display increased 4-HNE-induced nociceptive behavior. As proof of concept, the use of a selective peptide activator of PKCε (ΨεHSP90), which favors PKCε translocation to mitochondria and activation of PKCε-ALDH2 axis, was sufficient to block 4-HNE-induced hypersensitivity in WT, but not in ALDH2-deficient mice. Similarly, ΨεHSP90 administration prevented mechanical hypersensitivity induced by endogenous production of 4-HNE after carrageenan injection. These findings provide evidence that selective activation of mitochondrial PKCε-ALDH2 axis is important to mitigate aldehyde-mediated pain in rodents, suggesting that ΨεHSP90 and small molecules that mimic it may be a potential treatment for patients with pain.
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Go EJ, Ji J, Kim YH, Berta T, Park CK. Transient Receptor Potential Channels and Botulinum Neurotoxins in Chronic Pain. Front Mol Neurosci 2021; 14:772719. [PMID: 34776867 PMCID: PMC8586451 DOI: 10.3389/fnmol.2021.772719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/11/2021] [Indexed: 12/30/2022] Open
Abstract
Pain afflicts more than 1.5 billion people worldwide, with hundreds of millions suffering from unrelieved chronic pain. Despite widespread recognition of the importance of developing better interventions for the relief of chronic pain, little is known about the mechanisms underlying this condition. However, transient receptor potential (TRP) ion channels in nociceptors have been shown to be essential players in the generation and progression of pain and have attracted the attention of several pharmaceutical companies as therapeutic targets. Unfortunately, TRP channel inhibitors have failed in clinical trials, at least in part due to their thermoregulatory function. Botulinum neurotoxins (BoNTs) have emerged as novel and safe pain therapeutics because of their regulation of exocytosis and pro-nociceptive neurotransmitters. However, it is becoming evident that BoNTs also regulate the expression and function of TRP channels, which may explain their analgesic effects. Here, we summarize the roles of TRP channels in pain, with a particular focus on TRPV1 and TRPA1, their regulation by BoNTs, and briefly discuss the use of BoNTs for the treatment of chronic pain.
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Affiliation(s)
- Eun Jin Go
- Department of Physiology, Gachon Pain Center, Gachon University College of Medicine, Incheon, South Korea
| | - Jeongkyu Ji
- Gachon University College of Medicine, Incheon, South Korea
| | - Yong Ho Kim
- Department of Physiology, Gachon Pain Center, Gachon University College of Medicine, Incheon, South Korea
| | - Temugin Berta
- Department of Anesthesiology, Pain Research Center, University of Cincinnati Medical Center, Cincinnati, OH, United States
| | - Chul-Kyu Park
- Department of Physiology, Gachon Pain Center, Gachon University College of Medicine, Incheon, South Korea
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27
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Hamers A, Primus CP, Whitear C, Kumar NA, Masucci M, Montalvo Moreira SA, Rathod K, Chen J, Bubb K, Colas R, Khambata RS, Dalli J, Ahluwalia A. 20-HETE is a pivotal endogenous ligand for TRPV1-mediated neurogenic inflammation in the skin. Br J Pharmacol 2021; 179:1450-1469. [PMID: 34755897 DOI: 10.1111/bph.15726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 10/11/2021] [Accepted: 10/26/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Transient receptor potential cation channel subfamily V member 1 (TRPV1) is localised to sensory C-fibres and its opening leads to membrane depolarization, resulting in neuropeptide release and neurogenic inflammation. However, the identity of the endogenous activator of TRPV1 in this setting is unknown. The arachidonic acid (AA) metabolites 12-hydroperoxyeicosatetraenoyl acid (12-HpETE) and 20-hydroxyeicosatetraenoic acid (20-HETE) have emerged as potential endogenous activators of TRPV1 however, whether these lipids underlie TRPV1-mediated neurogenic inflammation remains unknown. EXPERIMENTAL APPROACH we analysed human cantharidin-induced blister samples and inflammatory responses in TRPV1 transgenic mice. KEY RESULTS In a human cantharidin-blister model the potent TRPV1 activators 20-HETE but not 12-HETE (stable metabolite of 12-HpETE) correlated with AA levels. Similarly, in mice levels of 20-HETE (but not 12-HETE) and AA were strongly positively correlated within the inflammatory milieu. Furthermore, LPS-induced oedema formation and neutrophil recruitment were substantially and significantly attenuated by pharmacological block or genetic deletion of TRPV1 channels, inhibition of 20-HETE formation or SP receptor neurokinin 1 (NK1 ) blockade. LPS treatment also increased cytochrome-P450 ώ-hydroxylase gene expression, the enzyme responsible for 20-HETE production. CONCLUSIONS AND IMPLICATIONS Taken together, our findings suggest that endogenously generated 20-HETE activates TRPV1 causing C-fibre activation and consequent oedema formation. These findings identify a novel pathway that may be useful in the therapeutics of diseases/conditions characterized by a prominent neurogenic inflammation, as in several skin diseases.
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Affiliation(s)
- Alexander Hamers
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Christopher P Primus
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Charlotte Whitear
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Nitin Ajit Kumar
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Michael Masucci
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Shanik A Montalvo Moreira
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Krishnaraj Rathod
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Jianmin Chen
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Kristen Bubb
- Monash Cardiovascular Research Centre, Monash University, Melbourne, Australia
| | - Romain Colas
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Rayomand S Khambata
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Jesmond Dalli
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
| | - Amrita Ahluwalia
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London
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Kuwashima Y, Yanagawa M, Abe M, Hiroshima M, Ueda M, Arita M, Sako Y. Comparative Analysis of Single-Molecule Dynamics of TRPV1 and TRPV4 Channels in Living Cells. Int J Mol Sci 2021; 22:ijms22168473. [PMID: 34445178 PMCID: PMC8395219 DOI: 10.3390/ijms22168473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/28/2021] [Accepted: 08/03/2021] [Indexed: 12/27/2022] Open
Abstract
TRPV1 and TRPV4, members of the transient receptor potential vanilloid family, are multimodal ion channels activated by various stimuli, including temperature and chemicals. It has been demonstrated that TRPV channels function as tetramers; however, the dynamics of the diffusion, oligomerization, and endocytosis of these channels in living cells are unclear. Here we undertook single-molecule time-lapse imaging of TRPV1 and TRPV4 in HEK 293 cells. Differences were observed between TRPV1 and TRPV4 before and after agonist stimulation. In the resting state, TRPV4 was more likely to form higher-order oligomers within immobile membrane domains than TRPV1. TRPV1 became immobile after capsaicin stimulation, followed by its gradual endocytosis. In contrast, TRPV4 was rapidly internalized upon stimulation with GSK1016790A. The selective loss of immobile higher-order oligomers from the cell surface through endocytosis increased the proportion of the fast-diffusing state for both subtypes. With the increase in the fast state, the association rate constants of TRPV1 and TRPV4 increased, regenerating the higher-order oligomers. Our results provide a possible mechanism for the different rates of endocytosis of TRPV1 and TRPV4 based on the spatial organization of the higher-order structures of the two TRPV channels.
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Affiliation(s)
- Yutaro Kuwashima
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Saitama, Japan; (Y.K.); (M.A.); (M.H.)
- Division of Physiological Chemistry and Metabolism, Keio University Faculty of Pharmacy, Tokyo 105-0011, Japan;
| | - Masataka Yanagawa
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Saitama, Japan; (Y.K.); (M.A.); (M.H.)
- Japan Science and Technology Agency (JST), PRESTO, 4-1-8, Honcho, Kawaguchi 332-0012, Saitama, Japan
- Correspondence: (M.Y.); (Y.S.)
| | - Mitsuhiro Abe
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Saitama, Japan; (Y.K.); (M.A.); (M.H.)
| | - Michio Hiroshima
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Saitama, Japan; (Y.K.); (M.A.); (M.H.)
- Laboratory for Cell Signaling Dynamics, RIKEN Center for Biosystems Dynamics Research (BDR), 6-2-3, Furuedai, Suita 565-0874, Osaka, Japan;
| | - Masahiro Ueda
- Laboratory for Cell Signaling Dynamics, RIKEN Center for Biosystems Dynamics Research (BDR), 6-2-3, Furuedai, Suita 565-0874, Osaka, Japan;
- Laboratory of Single Molecule Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita 565-0871, Osaka, Japan
| | - Makoto Arita
- Division of Physiological Chemistry and Metabolism, Keio University Faculty of Pharmacy, Tokyo 105-0011, Japan;
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama 230-0045, Kanagawa, Japan
- Cellular and Molecular Epigenetics Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Kanagawa, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Saitama, Japan; (Y.K.); (M.A.); (M.H.)
- Correspondence: (M.Y.); (Y.S.)
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Corydalis saxicola Bunting total alkaloids attenuate paclitaxel-induced peripheral neuropathy through PKCε/p38 MAPK/TRPV1 signaling pathway. Chin Med 2021; 16:58. [PMID: 34281577 PMCID: PMC8287815 DOI: 10.1186/s13020-021-00468-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/11/2021] [Indexed: 11/18/2022] Open
Abstract
Background Corydalis saxicola Bunting, affiliated with the Papaveraceae Juss., has been proven to work well in anti-inflammation, hemostasis, and analgesia. This study was designed to observe the effect and potential mechanism of Corydalis saxicola Bunting total alkaloids (CSBTA) on paclitaxel-induced peripheral neuropathy (PIPN). Materials and methods Rats were injected 2 mg/kg paclitaxel 4 times and administrated with 30 or 120 mg/kg CSBTA. Mechanical and thermal allodynia and hyperalgesia were tested. After 40 days, serum was collected to detect PGE2, TNF-α, and IL-1β by ELISA. The L4-L6 segment spinal cord, DRG, and plantar skin were harvested, and Western-blot or RT-qPCR analyzed protein and gene levels of pro-inflammatory cytokines, p38 MAPK, PKCε, and TRPV1. The PIPN cell model was established with paclitaxel (300 nM, 5 d) in primary DRG neurons. We examined the effect of CSBTA (25 μg/ml or 50 μg/ml) by measuring the mRNA levels in PGE2, TNF-α and CGRP, and the protein expression on the PKCε/p38 MAPK/TRPV1 signaling pathway in the PIPN cell model. Results The results showed that CSBTA effectively ameliorated allodynia and hyperalgesia, and regulated cytokines' contents (PGE2, TNF-α, and IL-1β) and neuropeptides (CGRP and SP) in different tissues in vivo. In addition, CSBTA significantly decreased cytokine gene levels of DRG neurons (PGE2, TNF-α, and CGRP) and the protein expressions of PKCε/p38 MAPK/TRPV1 signaling pathway in vivo and in vitro. Conclusion Therefore, CSBTA has a perspective therapeutic effect on the treatment of paclitaxel-induced peripheral neuropathy.
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30
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Biringer RG. A review of non-prostanoid, eicosanoid receptors: expression, characterization, regulation, and mechanism of action. J Cell Commun Signal 2021; 16:5-46. [PMID: 34173964 DOI: 10.1007/s12079-021-00630-6] [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: 05/21/2021] [Accepted: 06/07/2021] [Indexed: 11/29/2022] Open
Abstract
Eicosanoid signaling controls a wide range of biological processes from blood pressure homeostasis to inflammation and resolution thereof to the perception of pain and to cell survival itself. Disruption of normal eicosanoid signaling is implicated in numerous disease states. Eicosanoid signaling is facilitated by G-protein-coupled, eicosanoid-specific receptors and the array of associated G-proteins. This review focuses on the expression, characterization, regulation, and mechanism of action of non-prostanoid, eicosanoid receptors.
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Affiliation(s)
- Roger G Biringer
- College of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine, 5000 Lakewood Ranch Blvd, Bradenton, FL, 34211, USA.
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31
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Bagood MD, Isseroff RR. TRPV1: Role in Skin and Skin Diseases and Potential Target for Improving Wound Healing. Int J Mol Sci 2021; 22:ijms22116135. [PMID: 34200205 PMCID: PMC8201146 DOI: 10.3390/ijms22116135] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 12/14/2022] Open
Abstract
Skin is innervated by a multitude of sensory nerves that are important to the function of this barrier tissue in homeostasis and injury. The role of innervation and neuromediators has been previously reviewed so here we focus on the role of the transient receptor potential cation channel, subfamily V member 1 (TRPV1) in wound healing, with the intent of targeting it in treatment of non-healing wounds. TRPV1 structure and function as well as the outcomes of TRPV1-targeted therapies utilized in several diseases and tissues are summarized. In skin, keratinocytes, sebocytes, nociceptors, and several immune cells express TRPV1, making it an attractive focus area for treating wounds. Many intrinsic and extrinsic factors confound the function and targeting of TRPV1 and may lead to adverse or off-target effects. Therefore, a better understanding of what is known about the role of TRPV1 in skin and wound healing will inform future therapies to treat impaired and chronic wounds to improve healing.
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Affiliation(s)
- Michelle D. Bagood
- Department of Dermatology, School of Medicine, UC Davis, Sacramento, CA 95816, USA;
| | - R. Rivkah Isseroff
- Department of Dermatology, School of Medicine, UC Davis, Sacramento, CA 95816, USA;
- Dermatology Section, VA Northern California Health Care System, Mather, CA 95655, USA
- Correspondence: ; Tel.: +1-(916)-551-2606
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32
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Cao E. Structural mechanisms of transient receptor potential ion channels. J Gen Physiol 2021; 152:133640. [PMID: 31972006 PMCID: PMC7054860 DOI: 10.1085/jgp.201811998] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 01/03/2020] [Indexed: 12/26/2022] Open
Abstract
Transient receptor potential (TRP) ion channels are evolutionarily ancient sensory proteins that detect and integrate a wide range of physical and chemical stimuli. TRP channels are fundamental for numerous biological processes and are therefore associated with a multitude of inherited and acquired human disorders. In contrast to many other major ion channel families, high-resolution structures of TRP channels were not available before 2013. Remarkably, however, the subsequent “resolution revolution” in cryo-EM has led to an explosion of TRP structures in the last few years. These structures have confirmed that TRP channels assemble as tetramers and resemble voltage-gated ion channels in their overall architecture. But beyond the relatively conserved transmembrane core embedded within the lipid bilayer, each TRP subtype appears to be endowed with a unique set of soluble domains that may confer diverse regulatory mechanisms. Importantly, TRP channel structures have revealed sites and mechanisms of action of numerous synthetic and natural compounds, as well as those for endogenous ligands such as lipids, Ca2+, and calmodulin. Here, I discuss these recent findings with a particular focus on the conserved transmembrane region and how these structures may help to rationally target this important class of ion channels for the treatment of numerous human conditions.
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Affiliation(s)
- Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT
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Ottolini M, Sonkusare SK. The Calcium Signaling Mechanisms in Arterial Smooth Muscle and Endothelial Cells. Compr Physiol 2021; 11:1831-1869. [PMID: 33792900 PMCID: PMC10388069 DOI: 10.1002/cphy.c200030] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The contractile state of resistance arteries and arterioles is a crucial determinant of blood pressure and blood flow. Physiological regulation of arterial contractility requires constant communication between endothelial and smooth muscle cells. Various Ca2+ signals and Ca2+ -sensitive targets ensure dynamic control of intercellular communications in the vascular wall. The functional effect of a Ca2+ signal on arterial contractility depends on the type of Ca2+ -sensitive target engaged by that signal. Recent studies using advanced imaging methods have identified the spatiotemporal signatures of individual Ca2+ signals that control arterial and arteriolar contractility. Broadly speaking, intracellular Ca2+ is increased by ion channels and transporters on the plasma membrane and endoplasmic reticular membrane. Physiological roles for many vascular Ca2+ signals have already been confirmed, while further investigation is needed for other Ca2+ signals. This article focuses on endothelial and smooth muscle Ca2+ signaling mechanisms in resistance arteries and arterioles. We discuss the Ca2+ entry pathways at the plasma membrane, Ca2+ release signals from the intracellular stores, the functional and physiological relevance of Ca2+ signals, and their regulatory mechanisms. Finally, we describe the contribution of abnormal endothelial and smooth muscle Ca2+ signals to the pathogenesis of vascular disorders. © 2021 American Physiological Society. Compr Physiol 11:1831-1869, 2021.
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Affiliation(s)
- Matteo Ottolini
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Swapnil K Sonkusare
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.,Department of Molecular Physiology & Biological Physics, University of Virginia, Charlottesville, Virginia, USA.,Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
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34
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Neurogenic substance P-influences on action potential production in afferent neurons of the kidney? Pflugers Arch 2021; 473:633-646. [PMID: 33786667 PMCID: PMC8049925 DOI: 10.1007/s00424-021-02552-z] [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: 12/16/2020] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 12/23/2022]
Abstract
We recently showed that a substance P (SP)–dependent sympatho-inhibitory mechanism via afferent renal nerves is impaired in mesangioproliferative nephritis. Therefore, we tested the hypothesis that SP released from renal afferents inhibits the action potential (AP) production in their dorsal root ganglion (DRG) neurons. Cultured DRG neurons (Th11-L2) were investigated in current clamp mode to assess AP generation during both TRPV1 stimulation by protons (pH 6) and current injections with and without exposure to SP (0.5 µmol) or CGRP (0.5 µmol). Neurons were classified as tonic (sustained AP generation) or phasic (≤ 4 APs) upon current injection; voltage clamp experiments were performed for the investigation of TRPV1-mediated inward currents due to proton stimulation. Superfusion of renal neurons with protons and SP increased the number of action potentials in tonic neurons (9.6 ± 5 APs/10 s vs. 16.9 ± 6.1 APs/10 s, P < 0.05, mean ± SD, n = 7), while current injections with SP decreased it (15.2 ± 6 APs/600 ms vs. 10.2 ± 8 APs/600 ms, P < 0.05, mean ± SD, n = 29). Addition of SP significantly reduced acid-induced TRPV1-mediated currents in renal tonic neurons (− 518 ± 743 pA due to pH 6 superfusion vs. − 82 ± 50 pA due to pH 6 with SP superfusion). In conclusion, SP increased action potential production via a TRPV1-dependent mechanism in acid-sensitive renal neurons. On the other hand, current injection in the presence of SP led to decreased action potential production. Thus, the peptide SP modulates signaling pathways in renal neurons in an unexpected manner leading to both stimulation and inhibition of renal neuronal activity in different (e.g., acidic) environmental contexts.
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Buisseret B, Guillemot-Legris O, Ben Kouidar Y, Paquot A, Muccioli GG, Alhouayek M. Effects of R-flurbiprofen and the oxygenated metabolites of endocannabinoids in inflammatory pain mice models. FASEB J 2021; 35:e21411. [PMID: 33749884 DOI: 10.1096/fj.202002468r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 01/06/2021] [Accepted: 01/19/2021] [Indexed: 12/27/2022]
Abstract
Pain is one of the cardinal signs accompanying inflammation. The prostaglandins (PGs), synthetized from arachidonic acid by cyclooxygenase (COX)-2, are major bioactive lipids implicated in inflammation and pain. However, COX-2 is also able to metabolize other lipids, including the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA), to give glycerol ester (PG-G) and ethanolamide (PG-EA) derivatives of the PGs. Consequently, COX-2 can be considered as a hub not only controlling PG synthesis, but also PG-G and PG-EA synthesis. As they were more recently characterized, these endocannabinoid metabolites are less studied in nociception compared to PGs. Interestingly R-profens, previously considered as inactive enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), are substrate-selective COX inhibitors. Indeed, R-flurbiprofen can selectively block PG-G and PG-EA production, without affecting PG synthesis from COX-2. Therefore, we compared the effect of R-flurbiprofen and S-flurbiprofen in models of inflammatory pain triggered by local administration of lipopolysaccharides (LPS) and carrageenan in mice. Remarkably, the effects of flurbiprofen enantiomers on mechanical hyperalgesia seem to depend on (i) the inflammatory stimuli, (ii) the route of administration, and (iii) the timing of administration. We also assessed the effect of administration of the PG-Gs, PG-EAs, and PGs on LPS-induced mechanical hyperalgesia. Our data support the interest of studying the nonhydrolytic endocannabinoid metabolism in the context of inflammatory pain.
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Affiliation(s)
- Baptiste Buisseret
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Owein Guillemot-Legris
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Youssef Ben Kouidar
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Adrien Paquot
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Mireille Alhouayek
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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Gating of the capsaicin receptor TRPV1 by UVA-light and oxidants are mediated by distinct mechanisms. Cell Calcium 2021; 96:102391. [PMID: 33752082 DOI: 10.1016/j.ceca.2021.102391] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 02/22/2021] [Accepted: 03/09/2021] [Indexed: 02/07/2023]
Abstract
Redox-sensitivity is a common property of several transient receptor potential (TRP) ion channels. Oxidants and UVA-light activate TRPV2 by oxidizing methionine pore residues which are conserved in the capsaicin-receptor TRPV1. However, the redox-sensitivity of TRPV1 is regarded to depend on intracellular cysteine residues. In this study we examined if TRPV1 is gated by UVA-light, and if the conserved methionine residues are relevant for redox-sensitivity of TRPV1. Patch clamp recordings were performed to explore wildtype (WT) and mutants of human TRPV1 (hTRPV1). UVA-light induced hTRPV1-mediated membrane currents and potentiated both proton- and heat-evoked currents. The reducing agent dithiothreitol (DTT) prevented and partially reversed UVA-light induced sensitization of hTRPV1. UVA-light induced sensitization was reduced in the mutant hTRPV1-C158A/C387S/C767S (hTRPV1-3C). The remaining sensitivity to UVA-light of hTRRPV1-3C was not further reduced upon exchange of the methionine residues M568 and M645. While UVA-induced sensitization was reduced in the protein kinase C-insensitive mutant hTRPV1-S502A/S801A, the PKC-inhibitors chelerythrine chloride, staurosporine and Gö6976 did not reduce UVA-induced effects on hTRPV1-WT. While hTRPV1-3C was insensitive to the cysteine-selective oxidant diamide, it displayed a residual sensitivity to H2O2 and chloramine-T. However, the exchange of M568 and M645 in hTRPV1-3C did not further reduce these effects. Our data demonstrate that oxidants and UVA-light gate hTRPV1 by cysteine-dependent as well as cysteine-independent mechanisms. In contrast to TRPV2, the methionine residues 568 and 645 seem to be of limited relevance for redox-sensitivity of hTRPV1. Finally, UVA-light induced gating of hTRPV1 does not seem to require activation of protein kinase C.
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Li J, Zain M, Bonin RP. Differential modulation of thermal preference after sensitization by optogenetic or pharmacological activation of heat-sensitive nociceptors. Mol Pain 2021; 17:17448069211000910. [PMID: 33719729 PMCID: PMC7960897 DOI: 10.1177/17448069211000910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 01/24/2021] [Accepted: 02/10/2021] [Indexed: 11/22/2022] Open
Abstract
Common approaches to studying mechanisms of chronic pain and sensory changes in pre-clinical animal models involve measurement of acute, reflexive withdrawal responses evoked by noxious stimuli. These methods typically do not capture more subtle changes in sensory processing nor report on the consequent behavioral changes. In addition, data collection and analysis protocols are often labour-intensive and require direct investigator interactions, potentially introducing bias. In this study, we develop and characterize a low-cost, easily assembled behavioral assay that yields self-reported temperature preference from mice that is responsive to peripheral sensitization. This system uses a partially automated and freely available analysis pipeline to streamline the data collection process and enable objective analysis. We found that after intraplantar administration of the TrpV1 agonist, capsaicin, mice preferred to stay in cooler temperatures than saline injected mice. We further observed that gabapentin, a non-opioid analgesic commonly prescribed to treat chronic pain, reversed this aversion to higher temperatures. In contrast, optogenetic activation of the central terminals of TrpV1+ primary afferents via in vivo spinal light delivery did not induce a similar change in thermal preference, indicating a possible role for peripheral nociceptor activity in the modulation of temperature preference. We conclude that this easily produced and robust sensory assay provides an alternative approach to investigate the contribution of central and peripheral mechanisms of sensory processing that does not rely on reflexive responses evoked by noxious stimuli.
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Affiliation(s)
- Jerry Li
- Department of Human Biology: Neuroscience and Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Maham Zain
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Robert P Bonin
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
- University of Toronto Centre for the Study of Pain, University of Toronto, Toronto, Ontario, Canada
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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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Fischer MJM, Ciotu CI, Szallasi A. The Mysteries of Capsaicin-Sensitive Afferents. Front Physiol 2020; 11:554195. [PMID: 33391007 PMCID: PMC7772409 DOI: 10.3389/fphys.2020.554195] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 11/13/2020] [Indexed: 12/11/2022] Open
Abstract
A fundamental subdivision of nociceptive sensory neurons is named after their unique sensitivity to capsaicin, the pungent ingredient in hot chili peppers: these are the capsaicin-sensitive afferents. The initial excitation by capsaicin of these neurons manifested as burning pain sensation is followed by a lasting refractory state, traditionally referred to as "capsaicin desensitization," during which the previously excited neurons are unresponsive not only to capsaicin but a variety of unrelated stimuli including noxious heat. The long sought-after capsaicin receptor, now known as TRPV1 (transient receptor potential cation channel, subfamily V member 1), was cloned more than two decades ago. The substantial reduction of the inflammatory phenotype of Trpv1 knockout mice has spurred extensive efforts in the pharmaceutical industry to develop small molecule TRPV1 antagonists. However, adverse effects, most importantly hyperthermia and burn injuries, have so far prevented any compounds from progressing beyond Phase 2. There is increasing evidence that these limitations can be at least partially overcome by approaches outside of the mainstream pharmaceutical development, providing novel therapeutic options through TRPV1. Although ablation of the whole TRPV1-expressing nerve population by high dose capsaicin, or more selectively by intersectional genetics, has allowed researchers to investigate the functions of capsaicin-sensitive afferents in health and disease, several "mysteries" remain unsolved to date, including the molecular underpinnings of "capsaicin desensitization," and the exact role these nerves play in thermoregulation and heat sensation. This review tries to shed some light on these capsaicin mechanisms.
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Affiliation(s)
- Michael J. M. Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Cosmin I. Ciotu
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Arpad Szallasi
- 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
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Wang M, Thyagarajan B. Pain pathways and potential new targets for pain relief. Biotechnol Appl Biochem 2020; 69:110-123. [PMID: 33316085 DOI: 10.1002/bab.2086] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 12/06/2020] [Indexed: 12/15/2022]
Abstract
Pain is an unpleasant sensory and emotional experience that affects a sizable percentage of people on a daily basis. Sensory neurons known as nociceptors built specifically to detect damaging stimuli can be found throughout the body. They transmit information about noxious stimuli from mechanical, thermal, and chemical sources to the central nervous system and higher brain centers via electrical signals. Nociceptors express various channels and receptors such as voltage-gated sodium and calcium channels, transient receptor potential channels, and opioid receptors that allow them to respond in a highly specific manner to noxious stimuli. Attenuating the pain response can be achieved by inhibiting or altering the expression of these pain targets. Achieving a deeper understanding of how these receptors can be affected at the molecular level can lead to the development of novel pain therapies. This review will discuss the mechanisms of pain, introduce the various receptors that are responsible for detecting pain, and future directions in pharmacological therapies.
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Affiliation(s)
- Menglan Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Wyoming, Laramie, WY, USA
| | - Baskaran Thyagarajan
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Wyoming, Laramie, WY, USA
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Deficiency of Inositol Monophosphatase Activity Decreases Phosphoinositide Lipids and Enhances TRPV1 Function In Vivo. J Neurosci 2020; 41:408-423. [PMID: 33239401 PMCID: PMC7821860 DOI: 10.1523/jneurosci.0803-20.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 11/12/2020] [Accepted: 11/19/2020] [Indexed: 11/21/2022] Open
Abstract
Membrane remodeling by inflammatory mediators influences the function of sensory ion channels. The capsaicin- and heat-activated transient receptor potential vanilloid 1 (TRPV1) channel contributes to neurogenic inflammation and pain hypersensitivity, in part because of its potentiation downstream of phospholipase C-coupled receptors that regulate phosphoinositide lipid content. Here, we determined the effect of phosphoinositide lipids on TRPV1 function by combining genetic dissection, diet supplementation, and behavioral, biochemical, and functional analyses in Caenorhabditis elegans As capsaicin elicits heat and pain sensations in mammals, transgenic TRPV1 worms exhibit an aversive response to capsaicin. TRPV1 worms with low levels of phosphoinositide lipids display an enhanced response to capsaicin, whereas phosphoinositide lipid supplementation reduces TRPV1-mediated responses. A worm carrying a TRPV1 construct lacking the distal C-terminal domain features an enhanced response to capsaicin, independent of the phosphoinositide lipid content. Our results demonstrate that TRPV1 activity is enhanced when the phosphoinositide lipid content is reduced, and the C-terminal domain is key to determining agonist response in vivo.
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Legumain Induces Oral Cancer Pain by Biased Agonism of Protease-Activated Receptor-2. J Neurosci 2020; 41:193-210. [PMID: 33172978 DOI: 10.1523/jneurosci.1211-20.2020] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 02/07/2023] Open
Abstract
Oral squamous cell carcinoma (OSCC) is one of the most painful cancers, which interferes with orofacial function including talking and eating. We report that legumain (Lgmn) cleaves protease-activated receptor-2 (PAR2) in the acidic OSCC microenvironment to cause pain. Lgmn is a cysteine protease of late endosomes and lysosomes that can be secreted; it exhibits maximal activity in acidic environments. The role of Lgmn in PAR2-dependent cancer pain is unknown. We studied Lgmn activation in human oral cancers and oral cancer mouse models. Lgmn was activated in OSCC patient tumors, compared with matched normal oral tissue. After intraplantar, facial or lingual injection, Lgmn evoked nociception in wild-type (WT) female mice but not in female mice lacking PAR2 in NaV1.8-positive neurons (Par2Nav1.8), nor in female mice treated with a Lgmn inhibitor, LI-1. Inoculation of an OSCC cell line caused mechanical and thermal hyperalgesia that was reversed by LI-1. Par2Nav1.8 and Lgmn deletion attenuated mechanical allodynia in female mice with carcinogen-induced OSCC. Lgmn caused PAR2-dependent hyperexcitability of trigeminal neurons from WT female mice. Par2 deletion, LI-1, and inhibitors of adenylyl cyclase or protein kinase A (PKA) prevented the effects of Lgmn. Under acidified conditions, Lgmn cleaved within the extracellular N terminus of PAR2 at Asn30↓Arg31, proximal to the canonical trypsin activation site. Lgmn activated PAR2 by biased mechanisms in HEK293 cells to induce Ca2+ mobilization, cAMP formation, and PKA/protein kinase D (PKD) activation, but not β-arrestin recruitment or PAR2 endocytosis. Thus, in the acidified OSCC microenvironment, Lgmn activates PAR2 by biased mechanisms that evoke cancer pain.SIGNIFICANCE STATEMENT Oral squamous cell carcinoma (OSCC) is one of the most painful cancers. We report that legumain (Lgmn), which exhibits maximal activity in acidic environments, cleaves protease-activated receptor-2 (PAR2) on neurons to produce OSCC pain. Active Lgmn was elevated in OSCC patient tumors, compared with matched normal oral tissue. Lgmn evokes pain-like behavior through PAR2 Exposure of pain-sensing neurons to Lgmn decreased the current required to generate an action potential through PAR2 Inhibitors of adenylyl cyclase and protein kinase A (PKA) prevented the effects of Lgmn. Lgmn activated PAR2 to induce calcium mobilization, cAMP formation, and activation of protein kinase D (PKD) and PKA, but not β-arrestin recruitment or PAR2 endocytosis. Thus, Lgmn is a biased agonist of PAR2 that evokes cancer pain.
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Xiao R, Xu XZS. Temperature Sensation: From Molecular Thermosensors to Neural Circuits and Coding Principles. Annu Rev Physiol 2020; 83:205-230. [PMID: 33085927 DOI: 10.1146/annurev-physiol-031220-095215] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Temperature is a universal cue and regulates many essential processes ranging from enzymatic reactions to species migration. Due to the profound impact of temperature on physiology and behavior, animals and humans have evolved sophisticated mechanisms to detect temperature changes. Studies from animal models, such as mouse, Drosophila, and C. elegans, have revealed many exciting principles of thermosensation. For example, conserved molecular thermosensors, including thermosensitive channels and receptors, act as the initial detectors of temperature changes across taxa. Additionally, thermosensory neurons and circuits in different species appear to adopt similar logic to transduce and process temperature information. Here, we present the current understanding of thermosensation at the molecular and cellular levels. We also discuss the fundamental coding strategies of thermosensation at the circuit level. A thorough understanding of thermosensation not only provides key insights into sensory biology but also builds a foundation for developing better treatments for various sensory disorders.
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Affiliation(s)
- Rui Xiao
- Department of Aging and Geriatric Research, Institute on Aging and Center for Smell and Taste, University of Florida, Gainesville, Florida 32610, USA;
| | - X Z Shawn Xu
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA;
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Zhao X, Xia B, Cheng J, Zhu MX, Li Y. PKCε SUMOylation Is Required for Mediating the Nociceptive Signaling of Inflammatory Pain. Cell Rep 2020; 33:108191. [DOI: 10.1016/j.celrep.2020.108191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 07/27/2020] [Accepted: 09/02/2020] [Indexed: 12/20/2022] Open
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Long W, Fatehi M, Soni S, Panigrahi R, Philippaert K, Yu Y, Kelly R, Boonen B, Barr A, Golec D, Campbell SA, Ondrusova K, Hubert M, Baldwin T, Lemieux MJ, Light PE. Vitamin D is an endogenous partial agonist of the transient receptor potential vanilloid 1 channel. J Physiol 2020; 598:4321-4338. [PMID: 32721035 PMCID: PMC7589233 DOI: 10.1113/jp279961] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/20/2020] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS 25-Hydroxyvitamin D (25OHD) is a partial agonist of TRPV1 whereby 25OHD can weakly activate TRPV1 yet antagonize the stimulatory effects of the full TRPV1 agonists capsaicin and oleoyl dopamine. 25OHD binds to TRPV1 within the same vanilloid binding pocket as capsaicin. 25OHD inhibits the potentiating effects of PKC-mediated TRPV1 activity. 25OHD reduces T-cell activation and trigeminal neuron calcium signalling mediated by TRPV1 activity. These results provide evidence that TRPV1 is a novel receptor for the biological actions of vitamin D in addition to the well-documented effects of vitamin D upon the nuclear vitamin D receptor. The results may have important implications for our current understanding of certain diseases where TRPV1 and vitamin D deficiency have been implicated, such as chronic pain and autoimmune diseases, such as type 1 diabetes. ABSTRACT The capsaicin receptor TRPV1 plays an important role in nociception, inflammation and immunity and its activity is regulated by exogenous and endogenous lipophilic ligands. As vitamin D is lipophilic and involved in similar biological processes as TRPV1, we hypothesized that it directly regulates TRPV1 activity and function. Our calcium imaging and electrophysiological data demonstrate that vitamin D (25-hydroxyvitamin D (25OHD) and 1,25-hydroxyvitamin D (1,25OHD)) can weakly activate TRPV1 at physiologically relevant concentrations (100 nM). Furthermore, both 25OHD and 1,25OHD can inhibit capsaicin-induced TRPV1 activity (IC50 = 34.3 ± 0.2 and 11.5 ± 0.9 nM, respectively), but not pH-induced TRPV1 activity, suggesting that vitamin D interacts with TRPV1 in the same region as the TRPV1 agonist capsaicin. This hypothesis is supported by our in silico TRPV1 structural modelling studies, which place 25OHD in the same binding region as capsaicin. 25OHD also attenuates PKC-dependent TRPV1 potentiation via interactions with a known PKC phospho-acceptor residue in TRPV1. To provide evidence for a physiological role for the interaction of vitamin D with TRPV1, we employed two different cellular models known to express TRPV1: mouse CD4+ T-cells and trigeminal neurons. Our results indicate that 25OHD reduces TRPV1-induced cytokine release from T-cells and capsaicin-induced calcium activity in trigeminal neurons. In summary, we provide evidence that vitamin D is a novel endogenous regulator of TRPV1 channel activity that may play an important physiological role in addition to its known effects through the canonical nuclear vitamin D receptor pathway.
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Affiliation(s)
- Wentong Long
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Mohammad Fatehi
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Shubham Soni
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Rashmi Panigrahi
- BiochemistryFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Koenraad Philippaert
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Laboratory for Ion Channel ResearchDepartment of Cellular and Molecular MedicineVIB Center for Brain and Disease ResearchKU LeuvenLeuvenBelgium
| | - Yi Yu
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Rees Kelly
- Medical Microbiology & ImmunologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Brett Boonen
- Laboratory for Ion Channel ResearchDepartment of Cellular and Molecular MedicineVIB Center for Brain and Disease ResearchKU LeuvenLeuvenBelgium
| | - Amy Barr
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Dominic Golec
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Scott A. Campbell
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Katarina Ondrusova
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Matt Hubert
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Troy Baldwin
- Medical Microbiology & ImmunologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - M. Joanne Lemieux
- BiochemistryFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
| | - Peter E. Light
- Alberta Diabetes InstituteFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
- Departments of PharmacologyFaculty of Medicine & DentistryUniversity of AlbertaEdmontonCanada
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da Costa FLP, Pinto MCX, Santos DC, Carobin NV, de Jesus ICG, Ferreira LA, Guatimosim S, Silva JF, Castro Junior CJ. Ketamine potentiates TRPV1 receptor signaling in the peripheral nociceptive pathways. Biochem Pharmacol 2020; 182:114210. [PMID: 32882205 DOI: 10.1016/j.bcp.2020.114210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/11/2022]
Abstract
TRPV1 is a cation channel expressed in peripheral nociceptive pathways and its activation can trigger nociception signals to the brain. Ketamine is an intravenous anesthetic routinely used for anesthesia induction and with potent analgesic activity. Despite its proven depressant action on peripheral sensory pathways, the relationship between ketamine and TRPV1 receptors is still unclear. In this study, we evaluated the effect of ketamine injected peripherally in a rat model of spontaneous pain induced by capsaicin. We also investigated the effect of ketamine on Ca2+ transients in cultured dorsal root ganglia (DRG) neurons and HEK293 cells expressing the TRPV1 receptor (HEK-TRPV1 cells). Intraplantar administration of ketamine caused an unexpected increase in nocifensive behavior induced by capsaicin. Incubation of HEK-TRPV1 cells with 10 μM ketamine increased TRPV1 and PKCє phosphorylation. Ketamine potentiated capsaicin-induced Ca2+ transients in HEK-TRPV1 cells and DRG neurons. Ketamine also prevented TRPV1 receptor desensitization induced by successive applications of capsaicin. єV1-2, a PKCє inhibitor, reduced potentiation of capsaicin-induced Ca2+ transients by ketamine. Taken together, our data indicate that ketamine potentiates TRPV1 receptor sensitivity to capsaicin through a mechanism dependent on PKCє activity.
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Affiliation(s)
| | - Mauro Cunha Xavier Pinto
- Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Duana Carvalho Santos
- Santa Casa de Belo Horizonte Ensino e Pesquisa, Belo Horizonte, Minas Gerais, Brazil
| | | | - Itamar Couto Guedes de Jesus
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Minas Gerais, Brazil
| | - Luana Assis Ferreira
- Santa Casa de Belo Horizonte Ensino e Pesquisa, Belo Horizonte, Minas Gerais, Brazil
| | - Silvia Guatimosim
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Minas Gerais, Brazil
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Negative Modulation of TRPM8 Channel Function by Protein Kinase C in Trigeminal Cold Thermoreceptor Neurons. Int J Mol Sci 2020; 21:ijms21124420. [PMID: 32580281 PMCID: PMC7352406 DOI: 10.3390/ijms21124420] [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: 04/30/2020] [Revised: 05/30/2020] [Accepted: 06/12/2020] [Indexed: 01/19/2023] Open
Abstract
TRPM8 is the main molecular entity responsible for cold sensing. This polymodal ion channel is activated by cold, cooling compounds such as menthol, voltage, and rises in osmolality. In corneal cold thermoreceptor neurons (CTNs), TRPM8 expression determines not only their sensitivity to cold, but also their role as neural detectors of ocular surface wetness. Several reports suggest that Protein Kinase C (PKC) activation impacts on TRPM8 function; however, the molecular bases of this functional modulation are still poorly understood. We explored PKC-dependent regulation of TRPM8 using Phorbol 12-Myristate 13-Acetate to activate this kinase. Consistently, recombinant TRPM8 channels, cultured trigeminal neurons, and free nerve endings of corneal CTNs revealed a robust reduction of TRPM8-dependent responses under PKC activation. In corneal CTNs, PKC activation decreased ongoing activity, a key parameter in the role of TRPM8-expressing neurons as humidity detectors, and also the maximal cold-evoked response, which were validated by mathematical modeling. Biophysical analysis indicated that PKC-dependent downregulation of TRPM8 is mainly due to a decreased maximal conductance value, and complementary noise analysis revealed a reduced number of functional channels at the cell surface, providing important clues to understanding the molecular mechanisms of how PKC activity modulates TRPM8 channels in CTNs.
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Benítez-Angeles M, Morales-Lázaro SL, Juárez-González E, Rosenbaum T. TRPV1: Structure, Endogenous Agonists, and Mechanisms. Int J Mol Sci 2020; 21:ijms21103421. [PMID: 32408609 PMCID: PMC7279265 DOI: 10.3390/ijms21103421] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/29/2020] [Accepted: 04/29/2020] [Indexed: 12/13/2022] Open
Abstract
The Transient Receptor Potential Vanilloid 1 (TRPV1) channel is a polymodal protein with functions widely linked to the generation of pain. Several agonists of exogenous and endogenous nature have been described for this ion channel. Nonetheless, detailed mechanisms and description of binding sites have been resolved only for a few endogenous agonists. This review focuses on summarizing discoveries made in this particular field of study and highlighting the fact that studying the molecular details of activation of the channel by different agonists can shed light on biophysical traits that had not been previously demonstrated.
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Affiliation(s)
| | | | | | - Tamara Rosenbaum
- Correspondence: ; Tel.: +52-555-622-56-24; Fax: +52-555-622-56-07
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49
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Liu L, Yudin Y, Rohacs T. Diacylglycerol kinases regulate TRPV1 channel activity. J Biol Chem 2020; 295:8174-8185. [PMID: 32345612 DOI: 10.1074/jbc.ra119.012505] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/24/2020] [Indexed: 11/06/2022] Open
Abstract
The transient receptor potential vanilloid 1 (TRPV1) channel is activated by heat and by capsaicin, the pungent compound in chili peppers. Calcium influx through TRPV1 has been shown to activate a calcium-sensitive phospholipase C (PLC) enzyme and to lead to a robust decrease in phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] levels, which is a major contributor to channel desensitization. Diacylglycerol (DAG), the product of the PLC-catalyzed PI(4,5)P2 hydrolysis, activates protein kinase C (PKC). PKC is known to potentiate TRPV1 activity during activation of G protein-coupled receptors, but it is not known whether DAG modulates TRPV1 during desensitization. We found here that inhibition of diacylglycerol kinase (DAGK) enzymes reduces desensitization of native TRPV1 in dorsal root ganglion neurons as well as of recombinant TRPV1 expressed in HEK293 cells. The effect of DAGK inhibition was eliminated by mutating two PKC-targeted phosphorylation sites, Ser-502 and Ser-800, indicating involvement of PKC. TRPV1 activation induced only a small and transient increase in DAG levels, unlike the robust and more sustained increase induced by muscarinic receptor activation. DAGK inhibition substantially increased the DAG signal evoked by TRPV1 activation but not that evoked by M1 muscarinic receptor activation. Our results show that Ca2+ influx through TRPV1 activates PLC and DAGK enzymes and that the latter limits formation of DAG and negatively regulates TRPV1 channel activity. Our findings uncover a role of DAGK in ion channel regulation.
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Affiliation(s)
- Luyu Liu
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Yevgen Yudin
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
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Vellani V, Sabatini C, Milia C, Caselli G, Lanza M, Letari O, Rovati LC, Giacomoni C. CR4056, a powerful analgesic imidazoline-2 receptor ligand, inhibits the inflammation-induced PKCε phosphorylation and membrane translocation in sensory neurons. Br J Pharmacol 2019; 177:48-64. [PMID: 31454418 DOI: 10.1111/bph.14845] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/10/2019] [Accepted: 08/12/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE CR4056 is a first-in-class imidazoline-2 (I2 ) receptor ligand characterized by potent analgesic activity in different experimental animal models of pain. In a recent phase II clinical trial, CR4056 effectively reduced pain in patients with knee osteoarthritis. In the present study, we investigated the effects of CR4056 on PKCε translocation in vitro and on PKCε activation in vivo in dorsal root ganglia (DRG) neurons. EXPERIMENTAL APPROACH Effects of CR4056 on bradykinin-induced PKCε translocation were studied in rat sensory neurons by immunocytochemistry. PKCε activation was investigated by immunohistochemistry analysis of DRG from complete Freund's adjuvant-treated animals developing local hyperalgesia. The analgesic activity of CR4056 was tested on the same animals. KEY RESULTS CR4056 inhibited PKCε translocation with very rapid and long-lasting activity. CR4056 decreased hyperalgesia and phospho-PKCε immunoreactivity in the DRG neurons innervating the inflamed paw. The effect of CR4056 on PKCε translocation was blocked by pertussis toxin, implying that the intracellular pathways involved Gi proteins. The inhibition of PKCε translocation by CR4056 was independent of the α2 -adrenoeceptor and, surprisingly, was also independent of idazoxan-sensitive I2 binding sites. The I2 agonist 2BFI had no effect alone but potentiated the activity of low concentrations of CR4056. CONCLUSIONS AND IMPLICATIONS Our results demonstrate that CR4056 shares the ability to inhibit PKCε translocation with other analgesics. Whether the inhibition of PKCε involves binding to specific subtype(s) of I2 receptors should be further investigated. If so, this would be a new mode of action of a highly specific I2 receptor ligand.
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Affiliation(s)
- Vittorio Vellani
- Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze, Università di Modena e Reggio Emilia, Modena, Italy
| | - Chiara Sabatini
- Rottapharm Biotech, Monza, Italy.,PhD Program in Neuroscience, Dipartimento di Medicina e chirurgia, Università degli Studi di Milano-Bicocca, Monza, Italy
| | - Chiara Milia
- PhD Program in Neuroscience, Dipartimento di Medicina e chirurgia, Università degli Studi di Milano-Bicocca, Monza, Italy
| | | | | | | | | | - Chiara Giacomoni
- Dipartimento di Economia, Scienze e Diritto, Università degli Studi della Repubblica di San Marino, San Marino
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