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Berra-Romani R, Vargaz-Guadarrama A, Sánchez-Gómez J, Coyotl-Santiago N, Hernández-Arambide E, Avelino-Cruz JE, García-Carrasco M, Savio M, Pellavio G, Laforenza U, Lagunas-Martínez A, Moccia F. Histamine activates an intracellular Ca2+ signal in normal human lung fibroblast WI-38 cells. Front Cell Dev Biol 2022; 10:991659. [PMID: 36120576 PMCID: PMC9478493 DOI: 10.3389/fcell.2022.991659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Histamine is an inflammatory mediator that can be released from mast cells to induce airway remodeling and cause persistent airflow limitation in asthma. In addition to stimulating airway smooth muscle cell constriction and hyperplasia, histamine promotes pulmonary remodeling by inducing fibroblast proliferation, contraction, and migration. It has long been known that histamine receptor 1 (H1R) mediates the effects of histamine on human pulmonary fibroblasts through an increase in intracellular Ca2+ concentration ([Ca2+]i), but the underlying signaling mechanisms are still unknown. Herein, we exploited single-cell Ca2+ imaging to assess the signal transduction pathways whereby histamine generates intracellular Ca2+ signals in the human fetal lung fibroblast cell line, WI-38. WI-38 fibroblasts were loaded with the Ca2+-sensitive fluorophore, FURA-2/AM, and challenged with histamine in the absence and presence of specific pharmacological inhibitors to dissect the Ca2+ release/entry pathways responsible for the onset of the Ca2+ response. Histamine elicited complex intracellular Ca2+ signatures in WI-38 fibroblasts throughout a concentration range spanning between 1 µM and 1 mM. In accord, the Ca2+ response to histamine adopted four main temporal patterns, which were, respectively, termed peak, peak-oscillations, peak-plateau-oscillations, and peak-plateau. Histamine-evoked intracellular Ca2+ signals were abolished by pyrilamine, which selectively blocks H1R, and significantly reduced by ranitidine, which selectively inhibits H2R. Conversely, the pharmacological blockade of H3R and H4R did not affect the complex increase in [Ca2+]i evoked by histamine in WI-38 fibroblasts. In agreement with these findings, histamine-induced intracellular Ca2+ signals were initiated by intracellular Ca2+ release from the endoplasmic reticulum through inositol-1,4,5-trisphosphate (InsP3) receptors (InsP3R) and sustained by store-operated Ca2+ channels (SOCs). Conversely, L-type voltage-operated Ca2+ channels did not support histamine-induced extracellular Ca2+ entry. A preliminary transcriptomic analysis confirmed that WI-38 human lung fibroblasts express all the three InsP3R isoforms as well as STIM2 and Orai3, which represent the molecular components of SOCs. The pharmacological blockade of InsP3 and SOC, therefore, could represent an alternative strategy to prevent the pernicious effects of histamine on lung fibroblasts in asthmatic patients.
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Affiliation(s)
- Roberto Berra-Romani
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, México
- *Correspondence: Roberto Berra-Romani, ; Francesco Moccia,
| | - Ajelet Vargaz-Guadarrama
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Josué Sánchez-Gómez
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Nayeli Coyotl-Santiago
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Efraín Hernández-Arambide
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - José Everardo Avelino-Cruz
- Laboratory of Molecular Cardiology, Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Mario García-Carrasco
- Department of Immunology, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Monica Savio
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Giorgia Pellavio
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | | | - Alfredo Lagunas-Martínez
- Direction of Chronic Infections and Cancer, Research Center in Infection Diseases, National Institute of Public Health, Morelos, México
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, Pavia, Italy
- *Correspondence: Roberto Berra-Romani, ; Francesco Moccia,
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Renkhold L, Kollmann R, Inderwiedenstraße L, Kienitz MC. PKC-isoform specific regulation of receptor desensitization and KCNQ1/KCNE1 K + channel activity by mutant α 1B-adrenergic receptors. Cell Signal 2021; 91:110228. [PMID: 34958868 DOI: 10.1016/j.cellsig.2021.110228] [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: 10/25/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 11/25/2022]
Abstract
Activation of a specific protein kinase C (PKC) isoform during stimulation of Gq protein-coupled receptors (GqPCRs) is determined by homologous receptor desensitization that controls the spatiotemporal formation of downstream Gq signalling molecules. Furthermore, GqPCR-activated PKC isoforms specifically regulate receptor activity via a negative feedback mechanism. In the present study, we investigated the contribution of several phosphorylation sites in the α1B-adrenergic receptor (α1B-AR) for PKC and G protein coupled receptor kinase 2 (GRK2) to homologous receptor desensitization and effector modulation. We analyzed signalling events downstream to human wildtype α1B-ARs and α1B-ARs lacking PKC or GRK2 phosphorylation sites (Δ391-401, α1B-ΔPKC-AR and Δ402-520, α1B-ΔGRK-AR) by means of FRET-based biosensors in HEK293 that served as online-assays of receptor activity. K+ currents through KCNQ1/KCNE1 channels (IKs), which are regulated by both phosphatidylinositol 4,5-bisphosphate (PIP2)-depletion and/or phosphorylation by PKC, were measured as a functional readout of wildtype and mutant α1B-AR receptor activity. As a novel finding, we provide evidence that deletion of PKC and GRK2 phosphorylation sites in α1B-ARs abrogates the contribution of PKCα to homologous receptor desensitization. Instead, the time course of mutant receptor activity was specifically modulated by PKCβ. Mutant α1B-ARs displayed pronounced homologous receptor desensitization that was abolished by PKCβ-specific pharmacological inhibitors. IKs modulation during stimulation of wildtype and mutant α1B-ARs displayed transient inhibition and current facilitation after agonist withdrawal with reduced capability of mutant α1B-ARs to induce IKs inhibition. Pharmacological inhibition of the PKCβ isoform did not augment IKs reduction by mutant α1B-ARs, but shifted IKs modulation towards current facilitation. Coexpression of an inactive (dominant-negative) PKCδ isoform (DN-PKCδ) abolished IKs facilitation in α1B-ΔGRK-AR-expressing cells, but not in α1B-ΔPKC-AR-expressing cells. The data indicate that the differential modulation of IKs activity by α1B-ΔGRK- and α1B-ΔPKC-receptors is attributed to the activation of entirely distinct novel PKC isoforms. To summarize, specific phosphorylation sites within the wildtype and mutant α1B-adrenergic receptors are targeted by different PKC isoforms, resulting in differential regulation of receptor desensitization and effector function.
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Affiliation(s)
- Lina Renkhold
- Klinik für Hautkrankheiten, Universitätsklinikum Münster, Von-Esmarch-Str. 58, D-48149 Münster, Deutschland, Germany
| | - Rike Kollmann
- Department of Cellular Physiology, Institute of Physiology, Ruhr University Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany
| | - Leonie Inderwiedenstraße
- Department of Cellular Physiology, Institute of Physiology, Ruhr University Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany
| | - Marie-Cecile Kienitz
- Department of Cellular Physiology, Institute of Physiology, Ruhr University Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany.
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Chen X, Sooch G, Demaree IS, White FA, Obukhov AG. Transient Receptor Potential Canonical (TRPC) Channels: Then and Now. Cells 2020; 9:E1983. [PMID: 32872338 PMCID: PMC7565274 DOI: 10.3390/cells9091983] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022] Open
Abstract
Twenty-five years ago, the first mammalian Transient Receptor Potential Canonical (TRPC) channel was cloned, opening the vast horizon of the TRPC field. Today, we know that there are seven TRPC channels (TRPC1-7). TRPCs exhibit the highest protein sequence similarity to the Drosophila melanogaster TRP channels. Similar to Drosophila TRPs, TRPCs are localized to the plasma membrane and are activated in a G-protein-coupled receptor-phospholipase C-dependent manner. TRPCs may also be stimulated in a store-operated manner, via receptor tyrosine kinases, or by lysophospholipids, hypoosmotic solutions, and mechanical stimuli. Activated TRPCs allow the influx of Ca2+ and monovalent alkali cations into the cytosol of cells, leading to cell depolarization and rising intracellular Ca2+ concentration. TRPCs are involved in the continually growing number of cell functions. Furthermore, mutations in the TRPC6 gene are associated with hereditary diseases, such as focal segmental glomerulosclerosis. The most important recent breakthrough in TRPC research was the solving of cryo-EM structures of TRPC3, TRPC4, TRPC5, and TRPC6. These structural data shed light on the molecular mechanisms underlying TRPCs' functional properties and propelled the development of new modulators of the channels. This review provides a historical overview of the major advances in the TRPC field focusing on the role of gene knockouts and pharmacological tools.
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Affiliation(s)
- Xingjuan Chen
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Gagandeep Sooch
- The Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (G.S.); (I.S.D.)
| | - Isaac S. Demaree
- The Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (G.S.); (I.S.D.)
| | - Fletcher A. White
- The Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Alexander G. Obukhov
- The Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (G.S.); (I.S.D.)
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Lomax AE, Pradhananga S, Sessenwein JL, O'Malley D. Bacterial modulation of visceral sensation: mediators and mechanisms. Am J Physiol Gastrointest Liver Physiol 2019; 317:G363-G372. [PMID: 31290688 DOI: 10.1152/ajpgi.00052.2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The potential role of the intestinal microbiota in modulating visceral pain has received increasing attention during recent years. This has led to the identification of signaling pathways that have been implicated in communication between gut bacteria and peripheral pain pathways. In addition to the well-characterized impact of the microbiota on the immune system, which in turn affects nociceptor excitability, bacteria can modulate visceral afferent pathways by effects on enterocytes, enteroendocrine cells, and the neurons themselves. Proteases produced by bacteria, or by host cells in response to bacteria, can increase or decrease the excitability of nociceptive dorsal root ganglion (DRG) neurons depending on the receptor activated. Short-chain fatty acids generated by colonic bacteria are involved in gut-brain communication, and intracolonic short-chain fatty acids have pronociceptive effects in rodents but may be antinociceptive in humans. Gut bacteria modulate the synthesis and release of enteroendocrine cell mediators, including serotonin and glucagon-like peptide-1, which activate extrinsic afferent neurons. Deciphering the complex interactions between visceral afferent neurons and the gut microbiota may lead to the development of improved probiotic therapies for visceral pain.
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Affiliation(s)
- Alan E Lomax
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Ontario, Canada
| | - Sabindra Pradhananga
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Ontario, Canada
| | - Jessica L Sessenwein
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Ontario, Canada
| | - Dervla O'Malley
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Physiology, University College Cork, Cork, Ireland
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Long-Term Diabetic Microenvironment Augments the Decay Rate of Capsaicin-Induced Currents in Mouse Dorsal Root Ganglion Neurons. Molecules 2019; 24:775. [PMID: 30795543 PMCID: PMC6412516 DOI: 10.3390/molecules24040775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/16/2019] [Accepted: 02/19/2019] [Indexed: 12/04/2022] Open
Abstract
Individuals with end-stage diabetic peripheral neuropathy present with decreased pain sensation. Transient receptor potential vanilloid type 1 (TRPV1) is implicated in pain signaling and resides on sensory dorsal root ganglion (DRG) neurons. We investigated the expression and functional activity of TRPV1 in DRG neurons of the Ins2+/Akita mouse at 9 months of diabetes using immunohistochemistry, live single cell calcium imaging, and whole-cell patch-clamp electrophysiology. 2′,7′-Dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence assay was used to determine the level of Reactive Oxygen Species (ROS) in DRGs. Although TRPV1 expressing neuron percentage was increased in Ins2+/Akita DRGs at 9 months of diabetes compared to control, capsaicin-induced Ca2+ influx was smaller in isolated Ins2+/Akita DRG neurons, indicating impaired TRPV1 function. Consistently, capsaicin-induced Ca2+ influx was decreased in control DRG neurons cultured in the presence of 25 mM glucose for seven days versus those cultured with 5.5 mM glucose. The high glucose environment increased cytoplasmic ROS accumulation in cultured DRG neurons. Patch-clamp recordings revealed that capsaicin-activated currents decayed faster in isolated Ins2+/Akita DRG neurons as compared to those in control neurons. We propose that in poorly controlled diabetes, the accelerated rate of capsaicin-sensitive TRPV1 current decay in DRG neurons decreases overall TRPV1 activity and contributes to peripheral neuropathy.
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Svobodova B, Lichtenegger M, Platzer D, Di Giuro CML, de la Cruz GG, Glasnov T, Schreibmayer W, Groschner K. A single point mutation in the TRPC3 lipid-recognition window generates supersensitivity to benzimidazole channel activators. Cell Calcium 2019; 79:27-34. [PMID: 30798155 DOI: 10.1016/j.ceca.2019.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 12/27/2022]
Abstract
Mutation of a single residue within the recently identified lipid (diacylglycerol) recognition window of TRPC3 (G652A) was found to abolish channel activation via endogenous lipid mediators while retaining sensitivity to the non-lipid activator GSK1702934A (abb. GSK). The mechanism of this change in chemical sensing by TRPC3 was analysed by whole-cell and single channel electrophysiology as well as Ca2+ imaging. Currents initiated by GSK or the structural (benzimidazole) analog BI-2 were significantly larger in cells expressing the G652A mutant as compared to wild type (WT) channels. Whole cell patch-clamp experiments revealed that enhanced sensitivity to benzimidazoles was not due to augmented potency but reflected enhanced efficacy of benzimidazoles. Single channel analysis demonstrated that neither unitary conductance nor I-V characteristics were altered by the G652A mutation, precluding altered pore architecture as the basis of enhanced efficacy. These experiments uncovered a distinct gating pattern of BI-2-activated G652A mutant channels, featuring a unique, long-lived open state. Moreover, G652A mutant channels lacked PLC/diacylglycerol mediated cross-desensitization for GSK activation as typically observed for TRPC3. Lack of desensitization in G652A channels enabled large GSK/BI-2-induced Ca2+ signals in conditions that fully desensitized TRPC3 WT channels. We demonstrate that the lipid-recognition window of TRPC3 determines both sensitivity to lipid mediators and chemical gating by benzimidazoles. TRPC3 mutations within this lipid interaction site are suggested as a basis for chemogenetic targeting of TRPC3-signaling.
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Affiliation(s)
- Barbora Svobodova
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria
| | | | - Dieter Platzer
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria
| | | | | | - Toma Glasnov
- Institute of Chemistry, University of Graz, Austria
| | | | - Klaus Groschner
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria.
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Chen X, Taylor-Nguyen NN, Riley AM, Herring BP, White FA, Obukhov AG. The TRPC6 inhibitor, larixyl acetate, is effective in protecting against traumatic brain injury-induced systemic endothelial dysfunction. J Neuroinflammation 2019; 16:21. [PMID: 30704505 PMCID: PMC6354413 DOI: 10.1186/s12974-019-1407-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 01/11/2019] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The incidence of traumatic brain injuries (TBIs) is on the rise in the USA. Concussions, or mild TBIs without skull fracture, account for about 75% of all TBIs. Mild TBIs (mTBIs) lead to memory and cognitive deficits, headaches, intraocular pressure rises, axonal degeneration, neuroinflammation, and an array of cerebrovascular dysfunctions, including increased vascular permeability and decreased cerebral blood flow. It has been recently reported that besides vascular dysfunction in the cerebral circulation, mTBI may also cause a significant impairment of endothelial function in the systemic circulation, at least within mesenteric microvessels. In this study, we investigated whether mTBI affects endothelial function in aortas and determined the contribution of transient receptor potential canonical (TRPC) channels to modulating mTBI-associated endothelial dysfunction. METHODS We used a model of closed-head mTBI in C57BL/6, 129S, 129S-C57BL/6-F2 mice, and 129S-TRPC1 and 129S-C57BL/6-TRPC6 knockout mice to determine the effect of mTBI on endothelial function in mouse aortas employing ex vivo isometric tension measurements. Aortic tissue was also analyzed using immunofluorescence and qRT-PCR for TRPC6 expression following mTBI. RESULTS We show that in various strains of mice, mTBI induces a pronounced and long-lasting endothelial dysfunction in the aorta. Ablation of TRPC6 protects mice from mTBI-associated aortic endothelial dysfunction, while TRPC1 ablation does not impact brain injury-induced endothelial impairment in the aorta. Consistent with a role of TRPC6 activation following mTBI, we observed improved endothelial function in wild type control mice subjected to mTBI following 7-day in vivo treatment with larixyl acetate, an inhibitor of TRPC6 channels. Conversely, in vitro treatment with the pro-inflammatory endotoxin lipopolysaccharide, which activates endothelial TRPC6 in a Toll-like receptor type 4 (TLR4)-dependent manner, worsened aortic endothelial dysfunction in wild type mice. Lipopolysaccharide treatment in vitro failed to elicit endothelial dysfunction in TRPC6 knockout mice. No change in endothelial TRPC6 expression was observed 7 days following TBI. CONCLUSIONS These data suggest that TRPC6 activation may be critical for inducing endothelial dysfunction following closed-head mTBI and that pharmacological inhibition of the channel may be a feasible therapeutic strategy for preventing mTBI-associated systemic endothelial dysfunction.
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Affiliation(s)
- Xingjuan Chen
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Natalie N. Taylor-Nguyen
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Ashley M. Riley
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - B. Paul Herring
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Fletcher A. White
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Alexander G. Obukhov
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202 USA
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Ganesh BP, Hall A, Ayyaswamy S, Nelson JW, Fultz R, Major A, Haag A, Esparza M, Lugo M, Venable S, Whary M, Fox JG, Versalovic J. Diacylglycerol kinase synthesized by commensal Lactobacillus reuteri diminishes protein kinase C phosphorylation and histamine-mediated signaling in the mammalian intestinal epithelium. Mucosal Immunol 2018; 11:380-393. [PMID: 28745328 PMCID: PMC5785580 DOI: 10.1038/mi.2017.58] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 05/21/2017] [Indexed: 02/04/2023]
Abstract
Lactobacillus reuteri 6475 (Lr) of the human microbiome synthesizes histamine and can suppress inflammation via type 2 histamine receptor (H2R) activation in the mammalian intestine. Gut microbes such as Lr promote H2R signaling and may suppress H1R proinflammatory signaling pathways in parallel by unknown mechanisms. In this study, we identified a soluble bacterial enzyme known as diacylglycerol kinase (Dgk) from Lr that is secreted into the extracellular milieu and presumably into the intestinal lumen. DgK diminishes diacylglycerol (DAG) quantities in mammalian cells by promoting its metabolic conversion and causing reduced protein kinase C phosphorylation (pPKC) as a net effect in mammalian cells. We demonstrated that histamine synthesized by gut microbes (Lr) activates both mammalian H1R and H2R, but Lr-derived Dgk suppresses the H1R signaling pathway. Phospho-PKC and IκBα were diminished within the intestinal epithelium of mice and humans treated by wild-type (WT) Lr, but pPKC and IκBα were not decreased in treatment with ΔdgkA Lr. Mucosal IL-6 and systemic interleukin (IL)-1α, eotaxin, and granulocyte colony-stimulating factor (G-CSF) were suppressed in WT Lr, but not in ΔdgkA Lr colonized mice. Collectively, the commensal microbe Lr may act as a "microbial antihistamine" by suppressing intestinal H1R-mediated proinflammatory responses via diminished pPKC-mediated mammalian cell signaling.
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Affiliation(s)
- Bhanu Priya Ganesh
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
- Division of Comparative Medicine, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Anne Hall
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Sriram Ayyaswamy
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - James Willard Nelson
- Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Robert Fultz
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
- Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Angela Major
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Anthony Haag
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Magdalena Esparza
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Monica Lugo
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Susan Venable
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Mark Whary
- Division of Comparative Medicine, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - James G. Fox
- Division of Comparative Medicine, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - James Versalovic
- Departments of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
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Long-term spironolactone treatment reduces coronary TRPC expression, vasoconstriction, and atherosclerosis in metabolic syndrome pigs. Basic Res Cardiol 2017; 112:54. [PMID: 28756533 PMCID: PMC5534204 DOI: 10.1007/s00395-017-0643-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 07/17/2017] [Accepted: 07/24/2017] [Indexed: 12/12/2022]
Abstract
Coronary transient receptor potential canonical (TRPC) channel expression is elevated in metabolic syndrome (MetS). However, differential contribution of TRPCs to coronary pathology in MetS is not fully elucidated. We investigated the roles of TRPC1 and TRPC6 isoforms in coronary arteries of MetS pigs and determined whether long-term treatment with a mineralocorticoid receptor inhibitor, spironolactone, attenuates coronary TRPC expression and associated dysfunctions. MetS coronary arteries exhibited significant atherosclerosis, endothelial dysfunction, and increased histamine-induced contractions. Immunohistochemical studies revealed that TRPC6 immunostaining was significantly greater in the medial layer of MetS pig coronary arteries compared to that in Lean pigs, whereas little TRPC6 immunostaining was found in atheromas. Conversely, TRPC1 immunostaining was weak in the medial layer but strong in MetS atheromas, where it was predominantly localized to macrophages. Spironolactone treatment significantly decreased coronary TRPC expression and dysfunctions in MetS pigs. In vivo targeted delivery of the dominant-negative (DN)-TRPC6 cDNA to the coronary wall reduced histamine-induced calcium transients in the MetS coronary artery medial layer, implying a role for TRPC6 in mediating calcium influx in MetS coronary smooth muscles. Monocyte adhesion was increased in Lean pig coronary arteries cultured in the presence of aldosterone; and spironolactone antagonized this effect, suggesting that coronary mineralocorticoid receptor activation may regulate macrophage infiltration. TRPC1 expression in atheroma macrophages was associated with advanced atherosclerosis, whereas medial TRPC6 upregulation correlated with increased histamine-induced calcium transients and coronary contractility. We propose that long-term spironolactone treatment may be a therapeutic strategy to decrease TRPC expression and coronary pathology associated with MetS.
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Chen X, Li W, Riley AM, Soliman M, Chakraborty S, Stamatkin CW, Obukhov AG. Molecular Determinants of the Sensitivity to Gq/11-Phospholipase C-dependent Gating, Gd3+ Potentiation, and Ca2+ Permeability in the Transient Receptor Potential Canonical Type 5 (TRPC5) Channel. J Biol Chem 2016; 292:898-911. [PMID: 27920205 DOI: 10.1074/jbc.m116.755470] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/24/2016] [Indexed: 11/06/2022] Open
Abstract
Transient receptor potential canonical type 5 (TRPC5) is a Ca2+-permeable cation channel that is highly expressed in the brain and is implicated in motor coordination, innate fear behavior, and seizure genesis. The channel is activated by a signal downstream of the G-protein-coupled receptor (GPCR)-Gq/11-phospholipase C (PLC) pathway. In this study we aimed to identify the molecular mechanisms involved in regulating TRPC5 activity. We report that Arg-593, a residue located in the E4 loop near the TRPC5 extracellular Gd3+ binding site, is critical for conferring the sensitivity to GPCR-Gq/11-PLC-dependent gating on TRPC5. Indeed, guanosine 5'-O-(thiotriphosphate) and GPCR agonists only weakly activate the TRPC5R593A mutant, whereas the addition of Gd3+ rescues the mutant's sensitivity to GPCR-Gq/11-PLC-dependent gating. Computer modeling suggests that Arg-593 may cross-bridge the E3 and E4 loops, forming the "molecular fulcrum." While validating the model using site-directed mutagenesis, we found that the Tyr-542 residue is critical for establishing a functional Gd3+ binding site, the Tyr-541 residue participates in fine-tuning Gd3+-sensitivity, and that the Asn-584 residue determines Ca2+ permeability of the TRPC5 channel. This is the first report providing molecular insights into the molecular mechanisms regulating the sensitivity to GPCR-Gq/11-PLC-dependent gating of a receptor-operated channel.
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Affiliation(s)
- Xingjuan Chen
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Wennan Li
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Ashley M Riley
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Mario Soliman
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Saikat Chakraborty
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Christopher W Stamatkin
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Alexander G Obukhov
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
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Kienitz MC, Vladimirova D, Müller C, Pott L, Rinne A. Receptor Species-dependent Desensitization Controls KCNQ1/KCNE1 K+ Channels as Downstream Effectors of Gq Protein-coupled Receptors. J Biol Chem 2016; 291:26410-26426. [PMID: 27834678 DOI: 10.1074/jbc.m116.746974] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 11/09/2016] [Indexed: 12/17/2022] Open
Abstract
Activation of Gq protein-coupled receptors (GqPCRs) might induce divergent cellular responses, related to receptor-specific activation of different branches of the Gq signaling pathway. Receptor-specific desensitization provides a mechanism of effector modulation by restricting the spatiotemporal activation of signaling components downstream of Gq We quantified signaling events downstream of GqPCR activation with FRET-based biosensors in CHO and HEK 293 cells. KCNQ1/KCNE1 channels (IKs) were measured as a functional readout of receptor-specific activation. Activation of muscarinic M1 receptors (M1-Rs) caused robust and reversible inhibition of IKs. In contrast, activation of α1B-adrenergic receptors (α1B-ARs) induced transient inhibition of IKs, which turned into delayed facilitation after agonist withdrawal. As a novel finding, we demonstrate that GqPCR-specific kinetics of IKs modulation are determined by receptor-specific desensitization, evident at the level of Gαq activation, phosphatidylinositol 4,5-bisphosphate (PIP2) depletion, and diacylglycerol production. Sustained IKs inhibition during M1-R stimulation is attributed to robust membrane PIP2 depletion, whereas the rapid desensitization of α1B-AR delimits PIP2 reduction and augments current activation by protein kinase C (PKC). Overexpression of Ca2+-independent PKCδ did not affect the time course of α1B-AR-induced diacylglycerol formation, excluding a contribution of PKCδ to α1B-AR desensitization. Pharmacological inhibition of Ca2+-dependent PKC isoforms abolished fast α1B receptor desensitization and augmented IKs reduction, but did not affect IKs facilitation. These data indicate a contribution of Ca2+-dependent PKCs to α1B-AR desensitization, whereas IKs facilitation is induced by Ca2+-independent PKC isoforms. In contrast, neither inhibition of Ca2+-dependent/Ca2+-independent isoforms nor overexpression of PKCδ induced M1 receptor desensitization, excluding a contribution of PKC to M1-R-induced IKs modulation.
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Affiliation(s)
- Marie-Cécile Kienitz
- From the Institute of Physiology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Dilyana Vladimirova
- From the Institute of Physiology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Christian Müller
- From the Institute of Physiology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Lutz Pott
- From the Institute of Physiology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Andreas Rinne
- From the Institute of Physiology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
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Morita M, Nakane A, Maekawa S, Kudo Y. Pharmacological characterization of the involvement of protein kinase C in oscillatory and non-oscillatory calcium increases in astrocytes. J Pharmacol Sci 2015; 129:38-42. [PMID: 26349942 DOI: 10.1016/j.jphs.2015.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 08/09/2015] [Accepted: 08/11/2015] [Indexed: 01/24/2023] Open
Abstract
Evidence increasingly shows that astrocytes play a pivotal role in brain physiology and pathology via calcium dependent processes, thus the characterization of the calcium dynamics in astrocytes is of growing importance. We have previously reported that the epidermal growth factor and basic fibroblast growth factor up-regulate the oscillation of the calcium releases that are induced by stimuli, including glutamate in cultured astrocytes. This calcium oscillation is assumed to involve protein kinase C (PKC), which is activated together with the calcium releases as a consequence of inositol phospholipid hydrolysis. In the present study, this issue has been investigated pharmacologically by using astrocytes cultured with and without the growth factors. The pharmacological activation of PKC largely reduced the glutamate-induced oscillatory and non-oscillatory calcium increases. Meanwhile, PKC inhibitors increased the total amounts of both calcium increases without affecting the peak amplitudes and converted the calcium oscillations to non-oscillatory sustained calcium increases by abolishing the falling phases of the repetitive calcium increases. Furthermore, the pharmacological effects were consistent between both glutamate- and histamine-induced calcium oscillations. These results suggest that PKC up-regulates the removal of cytosolic calcium in astrocytes, and this up-regulation is essential for calcium oscillation in astrocytes cultured with growth factors.
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Affiliation(s)
- Mitsuhiro Morita
- Department of Biology, Kobe University Graduate School of Science, Kobe, 657-8501, Japan; School of Life Science, Tokyo University of Pharmacy and Life Science, Tokyo, 192-0392, Japan.
| | - Akira Nakane
- School of Life Science, Tokyo University of Pharmacy and Life Science, Tokyo, 192-0392, Japan
| | - Shohei Maekawa
- Department of Biology, Kobe University Graduate School of Science, Kobe, 657-8501, Japan
| | - Yoshihisa Kudo
- School of Life Science, Tokyo University of Pharmacy and Life Science, Tokyo, 192-0392, Japan
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