Light-Mediated Control over TRPC3-Mediated NFAT Signaling

Canonical transient receptor potential (TRPC) channels were identified as key players in maladaptive remodeling, with nuclear factor of activated T-cells (NFAT) transcription factors serving as downstream targets of TRPC-triggered Ca2+ entry in these pathological processes. Strikingly, the reconstitution of TRPC-NFAT signaling by heterologous expression yielded controversial results. Specifically, nuclear translocation of NFAT1 was found barely responsive to recombinant TRPC3, presumably based on the requirement of certain spatiotemporal signaling features. Here, we report efficient control of NFAT1 nuclear translocation in human embryonic kidney 293 (HEK293) cells by light, using a new photochromic TRPC benzimidazole activator (OptoBI-1) and a TRPC3 mutant with modified activator sensitivity. NFAT1 nuclear translocation was measured along with an all-optical protocol to record local and global Ca2+ pattern generated during light-mediated activation/deactivation cycling of TRPC3. Our results unveil the ability of wild-type TRPC3 to produce constitutive NFAT nuclear translocation. Moreover, we demonstrate that TRPC3 mutant that lacks basal activity enables spatiotemporally precise control over NFAT1 activity by photopharmacology. Our results suggest tight linkage between TRPC3 activity and NFAT1 nuclear translocation based on global cellular Ca2+ signals.

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The Na+/Ca2+ Exchanger Inhibitor, KB-R7943, Blocks a Nonselective Cation Channel Implicated in Chemosensory Transduction

Journal of Neurophysiology ◽

10.1152/jn.90903.2008 ◽

2009 ◽

Vol 101 (3) ◽

pp. 1151-1159 ◽

Cited By ~ 12

Author(s):

A. Pezier ◽

Y. V. Bobkov ◽

B. W. Ache

Keyword(s):

Transient Receptor Potential ◽

Single Channel ◽

Receptor Potential ◽

Trpc Channels ◽

Dependent Manner ◽

Open Probability ◽

Olfactory Transduction ◽

Voltage Dependent ◽

Chemosensory Transduction ◽

Transient Receptor

The mechanism(s) of olfactory transduction in invertebrates remains to be fully understood. In lobster olfactory receptor neurons (ORNs), a nonselective sodium-gated cation (SGC) channel, a presumptive transient receptor potential (TRP)C channel homolog, plays a crucial role in olfactory transduction, at least in part by amplifying the primary transduction current. To better determine the functional role of the channel, it is important to selectively block the channel independently of other elements of the transduction cascade, causing us to search for specific pharmacological blockers of the SGC channel. Given evidence that the Na+/Ca2+ exchange inhibitor, KB-R7943, blocks mammalian TRPC channels, we studied this probe as a potential blocker of the lobster SGC channel. KB-R7943 reversibly blocked the SGC current in both inside- and outside-out patch recordings in a dose- and voltage-dependent manner. KB-R7943 decreased the channel open probability without changing single channel amplitude. KB-R7943 also reversibly and in a dose-dependent manner inhibited both the odorant-evoked discharge of lobster ORNs and the odorant-evoked whole cell current. Our findings strongly imply that KB-R7943 potently blocks the lobster SGC channel and likely does so directly and not through its ability to block the Na+/Ca2+ exchanger.

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Regulation of Transient Receptor Potential Canonical 4 Activity by Phospholipase C-δ1

10.21203/rs.3.rs-107953/v1 ◽

2020 ◽

Author(s):

Juyeon Ko ◽

Jongyun Myeong ◽

Misun Kwak ◽

Insuk So

Keyword(s):

Phospholipase C ◽

Transient Receptor Potential ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Receptor Potential ◽

Regulation Mechanism ◽

Trpc Channels ◽

Transient Receptor Potential Canonical ◽

Cell Current ◽

Transient Receptor

Abstract Transient receptor potential canonical (TRPC) channels are non-selective calcium-permeable cation channels. It is suggested that TRPC4β and TRPC5 channels are regulated by phospholipase C (PLC) signaling, and are especially maintained by phosphatidylinositol 4,5-bisphosphate (PIP2). The PLCδ subtype is the most Ca2+-sensitive form among the isozymes which cleaves phospholipids to respond to the calcium rise. In this study, we investigated the regulation mechanism of TRPC channel by Ca2+, PLCδ1 and PIP2 signaling cascades. The interaction between TRPC4β and PLCδ1 was identified through the Fӧster resonance energy transfer (FRET) and co-immunoprecipitation (Co-IP). With the electrophysiological experiments, we found that TRPC4β-bound PLCδ1 reduces the overall whole-cell current of channel. The Ca2+-via opened channel promotes the activation of PLCδ1, which subsequently decreases PIP2 level. By comparison TRPC4β activity with or without PLCδ1 using differently [Ca2+]i buffered solution, we demonstrated that PLCδ1 functions in normal condition with physiological calcium range. The negative regulation effect of PLCδ1 on TRPC4β helps to elucidate the roles of each PIP2 binding residues whether they are concerned in channel maintenance or inhibition of channel activity.

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Canonical Transient Receptor Potential (TRPC) Channels in Nociception and Pathological Pain

Neural Plasticity ◽

10.1155/2020/3764193 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Zhi-Chuan Sun ◽

Sui-Bin Ma ◽

Wen-Guang Chu ◽

Dong Jia ◽

Ceng Luo

Keyword(s):

Chronic Pain ◽

Molecular Mechanisms ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Trpc Channels ◽

Canonical Transient Receptor Potential ◽

Abnormal Increase ◽

Pathological Pain ◽

Transient Receptor ◽

Underlying Mechanisms

Chronic pathological pain is one of the most intractable clinical problems faced by clinicians and can be devastating for patients. Despite much progress we have made in understanding chronic pain in the last decades, its underlying mechanisms remain elusive. It is assumed that abnormal increase of calcium levels in the cells is a key determinant in the transition from acute to chronic pain. Exploring molecular players mediating Ca2+ entry into cells and molecular mechanisms underlying activity-dependent changes in Ca2+ signaling in the somatosensory pain pathway is therefore helpful towards understanding the development of chronic, pathological pain. Canonical transient receptor potential (TRPC) channels form a subfamily of nonselective cation channels, which permit the permeability of Ca2+ and Na+ into the cells. Initiation of Ca2+ entry pathways by these channels triggers the development of many physiological and pathological functions. In this review, we will focus on the functional implication of TRPC channels in nociception with the elucidation of their role in the detection of external stimuli and nociceptive hypersensitivity.

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Structure–Function Relationship and Physiological Roles of Transient Receptor Potential Canonical (TRPC) 4 and 5 Channels

Cells ◽

10.3390/cells9010073 ◽

2019 ◽

Vol 9 (1) ◽

pp. 73

Author(s):

Jinsung Kim ◽

Juyeon Ko ◽

Chansik Hong ◽

Insuk So

Keyword(s):

Ion Channels ◽

Structure Function ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Trpc Channels ◽

Transient Receptor Potential Canonical ◽

Structure Function Relationship ◽

Transient Receptor ◽

Function Relationship ◽

Relationship Of

The study of the structure–function relationship of ion channels has been one of the most challenging goals in contemporary physiology. Revelation of the three-dimensional (3D) structure of ion channels has facilitated our understanding of many of the submolecular mechanisms inside ion channels, such as selective permeability, voltage dependency, agonist binding, and inter-subunit multimerization. Identifying the structure–function relationship of the ion channels is clinically important as well since only such knowledge can imbue potential therapeutics with practical possibilities. In a sense, recent advances in the understanding of the structure–relationship of transient receptor potential canonical (TRPC) channels look promising since human TRPC channels are calcium-permeable, non-selective cation channels expressed in many tissues such as the gastrointestinal (GI) tract, kidney, heart, vasculature, and brain. TRPC channels are known to regulate GI contractility and motility, pulmonary hypertension, right ventricular hypertrophy, podocyte injury, seizure, fear, anxiety-like behavior, and many others. In this article, we tried to elaborate recent findings of Cryo-EM (cryogenic-electron microscopy) based structural information of TRPC 4 and 5 channels and domain-specific functions of the channel, such as G-protein mediated activation mechanism, extracellular modification of the channel, homo/hetero-tetramerization, and pharmacological gating mechanisms.

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TRPC expression in mesenchymal stem cells

Cellular & Molecular Biology Letters ◽

10.2478/s11658-010-0031-3 ◽

2010 ◽

Vol 15 (4) ◽

Cited By ~ 9

Author(s):

Frederic Torossian ◽

Aurelie Bisson ◽

Jean-Pierre Vannier ◽

Olivier Boyer ◽

Marek Lamacz

Keyword(s):

Stem Cells ◽

Cell Proliferation ◽

Mesenchymal Stem Cells ◽

Cell Biology ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Trpc Channels ◽

Stem Cell Proliferation ◽

Regulatory Processes ◽

Transient Receptor

AbstractTransient receptor potential canonical (TRPC) channels are key players in calcium homeostasis and various regulatory processes in cell biology. Little is currently known about the TRPC subfamily members in mesenchymal stem cells (MSC), where they could play a role in cell proliferation. We report on the presence of TRPC1, 2, 4 and 6 mRNAs in MSC. Western blot and immunofluorescence staining indicate a membrane and intracellular distribution of TRPC1. Furthermore, the decrease in the level of TRPC1 protein caused by RNA interference is accompanied by the downregulation of cell proliferation. These results indicate that MSC express TRPC1, 2, 4 and 6 mRNA and that TRPC1 may play a role in stem cell proliferation.

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Canonical Transient Receptor Potential (TRPC) 1 Acts as a Negative Regulator for Vanilloid TRPV6-mediated Ca2+ Influx

Journal of Biological Chemistry ◽

10.1074/jbc.m112.400952 ◽

2012 ◽

Vol 287 (42) ◽

pp. 35612-35620 ◽

Cited By ~ 36

Author(s):

Rainer Schindl ◽

Reinhard Fritsch ◽

Isaac Jardin ◽

Irene Frischauf ◽

Heike Kahr ◽

...

Keyword(s):

Transient Receptor Potential ◽

Receptor Potential ◽

Negative Regulator ◽

Hek293 Cells ◽

Current Voltage ◽

Repeat Domain ◽

Transient Receptor ◽

Current Voltage Relationship

TRP proteins mostly assemble to homomeric channels but can also heteromerize, preferentially within their subfamilies. The TRPC1 protein is the most versatile member and forms various TRPC channel combinations but also unique channels with the distantly related TRPP2 and TRPV4. We show here a novel cross-family interaction between TRPC1 and TRPV6, a Ca2+ selective member of the vanilloid TRP subfamily. TRPV6 exhibited substantial co-localization and in vivo interaction with TRPC1 in HEK293 cells, however, no interaction was observed with TRPC3, TRPC4, or TRPC5. Ca2+ and Na+ currents of TRPV6-overexpressing HEK293 cells are significantly reduced by co-expression of TRPC1, correlating with a dramatically suppressed plasma membrane targeting of TRPV6. In line with their intracellular retention, remaining currents of TRPC1 and TRPV6 co-expression resemble in current-voltage relationship that of TRPV6. Studying the N-terminal ankyrin like repeat domain, structurally similar in the two proteins, we have found that these cytosolic segments were sufficient to mediate a direct heteromeric interaction. Moreover, the inhibitory role of TRPC1 on TRPV6 influx was also maintained by expression of only its N-terminal ankyrin-like repeat domain. Our experiments provide evidence for a functional interaction of TRPC1 with TRPV6 that negatively regulates Ca2+ influx in HEK293 cells.

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Expression and relative abundance of short transient receptor potential channels in the rat renal microcirculation

AJP Renal Physiology ◽

10.1152/ajprenal.00338.2003 ◽

2004 ◽

Vol 286 (3) ◽

pp. F546-F551 ◽

Cited By ~ 65

Author(s):

Carie S. Facemire ◽

Peter J. Mohler ◽

William J. Arendshorst

Keyword(s):

Relative Abundance ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Cell Types ◽

Calcium Entry ◽

Transient Receptor Potential Channels ◽

Trpc Channels ◽

Renal Microcirculation ◽

Resistance Vessels ◽

Transient Receptor

In the resistance vessels of the renal microcirculation, store- and/or receptor-operated calcium entry contribute to the rise in vascular smooth muscle cell (VSMC) intracellular calcium concentration in response to vasoconstrictor hormones. Short transient receptor potential (TRPC) channels are widely expressed in mammalian tissues and are proposed mediators of voltage-independent cation entry in multiple cell types, including VSMCs. The seven members of the TRPC gene family (TRPC1-7) encode subunit proteins that are thought to form homo- and heterotetrameric channels that are differentially regulated depending on their subunit composition. In the present study, we demonstrate the relative abundance of TRPC mRNA and protein in freshly isolated rat renal resistance vessels, glomeruli, and aorta. TRPC1, 3, 4, 5, and 6 mRNA and protein were detected in both renal resistance vessels and aorta, whereas TRPC2 and TRPC7 mRNA were not expressed. TRPC1, 3, 5, and 6 protein was present in glomeruli. TRPC3 and TRPC6 protein levels were significantly greater in the renal resistance vessels, about six- to eightfold higher than in aorta. These data suggest that TRPC3 and TRPC6 may play a role in mediating voltage-independent calcium entry in renal resistance vessels that is functionally distinct from that in aorta.

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Elucidation of a TRPC6-TRPC5 Channel Cascade That Restricts Endothelial Cell Movement

Molecular Biology of the Cell ◽

10.1091/mbc.e07-08-0765 ◽

2008 ◽

Vol 19 (8) ◽

pp. 3203-3211 ◽

Cited By ~ 54

Author(s):

Pinaki Chaudhuri ◽

Scott M. Colles ◽

Manjunatha Bhat ◽

David R. Van Wagoner ◽

Lutz Birnbaumer ◽

...

Keyword(s):

Intracellular Calcium ◽

Calcium Concentration ◽

Transient Receptor Potential ◽

Calcium Influx ◽

Cell Movement ◽

Receptor Potential ◽

Receptor Activation ◽

Calcium Stores ◽

Trpc Channels ◽

Transient Receptor

Canonical transient receptor potential (TRPC) channels are opened by classical signal transduction events initiated by receptor activation or depletion of intracellular calcium stores. Here, we report a novel mechanism for opening TRPC channels in which TRPC6 activation initiates a cascade resulting in TRPC5 translocation. When endothelial cells (ECs) are incubated in lysophosphatidylcholine (lysoPC), rapid translocation of TRPC6 initiates calcium influx that results in externalization of TRPC5. Activation of this TRPC6–5 cascade causes a prolonged increase in intracellular calcium concentration ([Ca2+]i) that inhibits EC movement. When TRPC5 is down-regulated with siRNA, the lysoPC-induced rise in [Ca2+]i is shortened and the inhibition of EC migration is lessened. When TRPC6 is down-regulated or EC from TRPC6−/− mice are studied, lysoPC has minimal effect on [Ca2+]i and EC migration. In addition, TRPC5 is not externalized in response to lysoPC, supporting the dependence of TRPC5 translocation on the opening of TRPC6 channels. Activation of this novel TRPC channel cascade by lysoPC, resulting in the inhibition of EC migration, could adversely impact on EC healing in atherosclerotic arteries where lysoPC is abundant.

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Role of Transient Receptor Potential Channels in Cholecystokinin-Induced Activation of Cultured Vagal Afferent Neurons

Endocrinology ◽

10.1210/en.2010-0504 ◽

2010 ◽

Vol 151 (11) ◽

pp. 5237-5246 ◽

Cited By ~ 16

Author(s):

Huan Zhao ◽

Steven M. Simasko

Keyword(s):

Transient Receptor Potential ◽

Receptor Potential ◽

Cytosolic Calcium ◽

Membrane Depolarization ◽

Induced Response ◽

Trpc Channels ◽

Afferent Neurons ◽

Trpv Channels ◽

Vagal Afferent ◽

Transient Receptor

Cholecystokinin (CCK), an endogenous brain-gut peptide, is released after food intake and promotes the process of satiation via activation of the vagus nerve. In vitro, CCK increases cytosolic calcium concentrations and produces membrane depolarization in a subpopulation of vagal afferent neurons. However, the specific mechanisms and ionic conductances that mediate these effects remain unclear. In this study we used calcium imaging, electrophysiological measurements, and single cell PCR analysis on cultured vagal afferent neurons to address this issue directly. A cocktail of blockers of voltage-dependent calcium channels (VDCC) failed to block CCK-induced calcium responses. In addition, SKF96365, a compound that blocks both VDCC and the C family of transient receptor potential (TRP) channels, also failed to prevent responses to CCK. Together these results suggest that CCK-induced calcium influx is not subsequent to the membrane depolarization. Ruthenium red, an inhibitor of the TRPV family and TRPA1, blocked both depolarizing responses to CCK and CCK-induced calcium increases, but had no effect on the KCl-induced calcium response. Selective block of TRPV1 and TRPA1 channels with SB366791 and HC030031, respectively, had minor effects on the CCK-induced response. Application of 2-aminoethoxydiphenyl borate, an activator of select TRPV channels but a blocker of several TRPC channels, either had no effect or enhanced the responses to CCK. Further, results from PCR experiments revealed a significant clustering of TRPV2-5 in neurons expressing CCK1 receptors. These observations demonstrate that CCK-induced increases in cytosolic calcium and membrane depolarization of vagal afferent neurons are likely mediated by TRPV channels, excluding TRPV1.

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Counteracting effect of TRPC1-associated Ca2+influx on TNF-α-induced COX-2-dependent prostaglandin E2production in human colonic myofibroblasts

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00354.2010 ◽

2011 ◽

Vol 301 (2) ◽

pp. G356-G367 ◽

Cited By ~ 20

Author(s):

Lin Hai ◽

Yasuhiro Kawarabayashi ◽

Yuko Imai ◽

Akira Honda ◽

Ryuji Inoue

Keyword(s):

Transient Receptor Potential ◽

Nuclear Translocation ◽

Receptor Potential ◽

Selective Inhibition ◽

Surface Expression ◽

Cell Surface Expression ◽

Prostaglandin E ◽

Tnf Α ◽

Cox 2 ◽

Transient Receptor

TNF-α-NF-κB signaling plays a central role in inflammation, apoptosis, and neoplasia. One major consequence of this signaling in the gut is increased production of prostaglandin E2(PGE2) via cyclooxygenase-2 (COX-2) induction in myofibroblasts, which has been reported to be dependent on Ca2+. In this study, we explored a potential role of canonical transient receptor potential (TRPC) proteins in this Ca2+-mediated signaling using a human colonic myofibroblast cell line CCD-18Co. In CCD-18Co cell, treatment with TNF-α greatly enhanced Ca2+influx induced by store depletion along with increased cell-surface expression of TRPC1 protein (but not of the other TRPC isoforms) and induction of a Gd3+-sensitive nonselective cationic conductance. Selective inhibition of TRPC1 expression by small interfering RNA (siRNA) or functionally effective TRPC1 antibody targeting the near-pore region of TRPC1 (T1E3) antagonized the enhancement of store-dependent Ca2+influx by TNF-α, whereas potentiated TNF-α induced PGE2production. Overexpression of TRPC1 in CCD-18Co produced opposite consequences. Inhibitors of NF-κB (curcumin, SN-50) attenuated TNF-α-induced enhancement of TRPC1 expression, store-dependent Ca2+influx, and COX-2-dependent PGE2production. In contrast, inhibition of calcineurin-nuclear factor of activated T-cell proteins (NFAT) signaling by FK506 or NFAT Activation Inhibitor III enhanced the PGE2production without affecting TRPC1 expression and the Ca2+influx. Finally, the suppression of store-dependent Ca2+influx by T1E3 antibody or siRNA knockdown significantly facilitated TNF-α-induced NF-κB nuclear translocation. In aggregate, these results strongly suggest that, in colonic myofibroblasts, NF-κB and NFAT serve as important positive and negative transcriptional regulators of TNF-α-induced COX-2-dependent PGE2production, respectively, at the downstream of TRPC1-associated Ca2+influx.

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