1
|
Phelan KD, Shwe UT, Zheng F. Pharmacological Differences between Native Homomeric Transient Receptor Potential Canonical Type 4 Channels and Heteromeric Transient Receptor Potential Canonical Type 1/4 Channels in Lateral Septal Neurons. Pharmaceuticals (Basel) 2023; 16:1291. [PMID: 37765099 PMCID: PMC10534382 DOI: 10.3390/ph16091291] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Given the unique expression patterns and revelations of its critical involvement in a host of neurological disorders, the TRPC1/4/5 subgroup has become an intense target of drug development, and some compounds are now in clinical trials. However, little is known about the exact subunit composition of this subfamily of TRPC channels in various native tissues, and whether it has functional and pharmacological implications. In this study, we investigated the effects of two TRPC4 modulators located in the lateral septum, in which a metabotropic glutamate receptor (mGluR) agonist-induced plateau potential is mediated by TRPC channels composed of TRPC1 and TRPC4. Lateral septal neurons were recorded intracellularly in brain slices using sharp electrodes. Drugs were applied via bath superfusion. We showed that the plateau potential in mice lacking TRPC1 is modulated by ML204 and La3+ in a manner that is like homomeric TRPC4 channels in artificial expression systems. However, the plateau potential that is primarily mediated by heteromeric TRPC1/4 channels in lateral septal neurons in wildtype mice was modulated differently by ML204 and La3+. Our data suggest that native homomeric TRPC4 channels and heteromeric TRPC1/4 channels are pharmacologically distinct, and the current drug development strategy regarding TRPC1/4/5 may need to be reevaluated.
Collapse
Affiliation(s)
- Kevin D. Phelan
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
| | - U Thaung Shwe
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Fang Zheng
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| |
Collapse
|
2
|
Kim A, Kim AR, Jeon YE, Yoo YJ, Yang YM, Bak EJ. TRPC expression in human periodontal ligament cells and the periodontal tissue of periodontitis mice: a preliminary study. Lab Anim Res 2023; 39:19. [PMID: 37653550 PMCID: PMC10472569 DOI: 10.1186/s42826-023-00171-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 09/02/2023] Open
Abstract
BACKGROUND Transient receptor potential canonical (TRPC) channels are non-selective cationic channels with permeability to Ca2+ and Na+. Despite their importance, there are currently few studies on TRPC in the periodontal ligament (PDL) and bone cells in the dental field. To provide biological information regarding TRPC in PDL cells and periodontal tissue, we evaluated TRPC channels expression in the osteoblast differentiation of PDL cells and periodontitis-induced tissue. Human PDL cells were cultured in osteogenic differentiation media for 28 days, and the expression of Runx2, osteocalcin (OCN), and TRPC1, 3, 4, and 6 was evaluated by real-time PCR. In ligature-induced periodontitis mice, the alveolar bone and osteoid areas, the osteoclast number, and the expression of Runx2, OCN, TRPC3, and TRPC6 was evaluated by H&E staining, TRAP staining, and immunohistochemistry, respectively. RESULTS In the PDL cell differentiation group, TRPC6 expression peaked on day 7 and TRPC3 expression generally increased during differentiation. During the 28 days of periodontitis progression, alveolar bone loss and osteoclast numbers increased compared to the control group during the experimental period and the osteoid area increased from day 14. TRPC6 expression in the periodontitis group increased in the PDL area and in the osteoblasts compared to the control group, whereas TRPC3 expression increased only in the PDL area on days 7 and 28. CONCLUSIONS These results indicate changes of TRPC3 and TRPC6 expression in PDL cells that were differentiating into osteoblasts and in periodontitis-induced tissue, suggesting the need for research on the role of TRPC in osteoblast differentiation or periodontitis progression.
Collapse
Affiliation(s)
- Aeryun Kim
- Department of Oral Biology, Yonsei University College of Dentistry, 134 Sinchon Dong, Seodaemun-gu, Seoul, 03722, Republic of Korea
- Oral Health Research Institute, Apple Tree Dental Hospital, Bucheon, 14642, Republic of Korea
| | - Ae Ri Kim
- Department of Oral Biology, Yonsei University College of Dentistry, 134 Sinchon Dong, Seodaemun-gu, Seoul, 03722, Republic of Korea
- BK21 FOUR Project, Yonsei University College of Dentistry, Seoul, 03722, Republic of Korea
| | - Yeong-Eui Jeon
- Department of Oral Biology, Yonsei University College of Dentistry, 134 Sinchon Dong, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Yun-Jung Yoo
- Department of Oral Biology, Yonsei University College of Dentistry, 134 Sinchon Dong, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Yu-Mi Yang
- Department of Oral Biology, Yonsei University College of Dentistry, 134 Sinchon Dong, Seodaemun-gu, Seoul, 03722, Republic of Korea.
| | - Eun-Jung Bak
- Department of Oral Biology, Yonsei University College of Dentistry, 134 Sinchon Dong, Seodaemun-gu, Seoul, 03722, Republic of Korea.
| |
Collapse
|
3
|
Hu Q, Ahmad AA, Seidel T, Hunter C, Streiff M, Nikolova L, Spitzer KW, Sachse FB. Location and function of transient receptor potential canonical channel 1 in ventricular myocytes. J Mol Cell Cardiol 2020; 139:113-123. [PMID: 31982426 DOI: 10.1016/j.yjmcc.2020.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 12/16/2019] [Accepted: 01/21/2020] [Indexed: 11/17/2022]
Abstract
Transient receptor potential canonical 1 (TRPC1) protein is abundantly expressed in cardiomyocytes. While TRPC1 is supposed to be critically involved in cardiac hypertrophy, its physiological role in cardiomyocytes is poorly understood. We investigated the subcellular location of TRPC1 and its contribution to Ca2+ signaling in mammalian ventricular myocytes. Immunolabeling, three-dimensional scanning confocal microscopy and quantitative colocalization analysis revealed an abundant intracellular location of TRPC1 in neonatal rat ventricular myocytes (NRVMs) and adult rabbit ventricular myocytes. TRPC1 was colocalized with intracellular proteins including sarco/endoplasmic reticulum Ca2+ ATPase 2 in the sarcoplasmic reticulum (SR). Colocalization with wheat germ agglutinin, which labels the glycocalyx and thus marks the sarcolemma including the transverse tubular system, was low. Super-resolution and immunoelectron microscopy supported the intracellular location of TRPC1. We investigated Ca2+ signaling in NRVMs after adenoviral TRPC1 overexpression or silencing. In NRVMs bathed in Na+ and Ca2+ free solution, TRPC1 overexpression and silencing was associated with a decreased and increased SR Ca2+ content, respectively. In isolated rabbit cardiomyocytes bathed in Na+ and Ca2+ free solution, we found an increased decay of the cytosolic Ca2+ concentration [Ca2+]i and increased SR Ca2+ content in the presence of the TRPC channel blocker SKF-96365. In a computational model of rabbit ventricular myocytes at physiological pacing rates, Ca2+ leak through SR TRPC channels increased the systolic and diastolic [Ca2+]i with only minor effects on the action potential and SR Ca2+ content. Our studies suggest that TRPC1 channels are localized in the SR, and not present in the sarcolemma of ventricular myocytes. The studies provide evidence for a role of TRPC1 as a contributor to SR Ca2+ leak in cardiomyocytes, which was previously explained by ryanodine receptors only. We propose that the findings will guide us to an understanding of TRPC1 channels as modulators of [Ca2+]i and contractility in cardiomyocytes.
Collapse
Affiliation(s)
- Qinghua Hu
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Cardiovascular Surgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410078, China
| | - Azmi A Ahmad
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Thomas Seidel
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Chris Hunter
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Molly Streiff
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Linda Nikolova
- Core Research Facilities, Health Sciences Center, University of Utah, Salt Lake City, UT 84112, USA
| | - Kenneth W Spitzer
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Frank B Sachse
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA.
| |
Collapse
|
4
|
Vascular smooth muscle TRPC3 channels facilitate the inverse hemodynamic response during status epilepticus. Sci Rep 2020; 10:812. [PMID: 31964991 PMCID: PMC6972937 DOI: 10.1038/s41598-020-57733-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 01/06/2020] [Indexed: 11/08/2022] Open
Abstract
Human status epilepticus (SE) is associated with a pathological reduction in cerebral blood flow termed the inverse hemodynamic response (IHR). Canonical transient receptor potential 3 (TRPC3) channels are integral to the propagation of seizures in SE, and vascular smooth muscle cell (VSMC) TRPC3 channels participate in vasoconstriction. Therefore, we hypothesize that cerebrovascular TRPC3 channels may contribute to seizure-induced IHR. To examine this possibility, we developed a smooth muscle-specific TRPC3 knockout (TRPC3smcKO) mouse. To quantify changes in neurovascular coupling, we combined laser speckle contrast imaging with simultaneous electroencephalogram recordings. Control mice exhibited multiple IHRs, and a limited increase in cerebral blood flow during SE with a high degree of moment-to-moment variability in which blood flow was not correlated with neuronal activity. In contrast, TRPC3smcKO mice showed a greater increase in blood flow that was less variable and was positively correlated with neuronal activity. Genetic ablation of smooth muscle TRPC3 channels shortened the duration of SE by eliminating a secondary phase of intense seizures, which was evident in littermate controls. Our results are consistent with the idea that TRPC3 channels expressed by cerebral VSMCs contribute to the IHR during SE, which is a critical factor in the progression of SE.
Collapse
|
5
|
Zhang ZM, Wu XL, Zhang GY, Ma X, He DX. Functional food development: Insights from TRP channels. J Funct Foods 2019. [DOI: 10.1016/j.jff.2019.03.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
|
6
|
Subcutaneous white adipocytes express a light sensitive signaling pathway mediated via a melanopsin/TRPC channel axis. Sci Rep 2017; 7:16332. [PMID: 29180820 PMCID: PMC5703708 DOI: 10.1038/s41598-017-16689-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 11/15/2017] [Indexed: 12/19/2022] Open
Abstract
Subcutaneous white adipose tissue (scWAT) is the major fat depot in humans and is a central player in regulating whole body metabolism. Skin exposure to UV wavelengths from sunlight is required for Vitamin D synthesis and pigmentation, although it is plausible that longer visible wavelengths that penetrate the skin may regulate scWAT function. In this regard, we discovered a novel blue light-sensitive current in human scWAT that is mediated by melanopsin coupled to transient receptor potential canonical cation channels. This pathway is activated at physiological intensities of light that penetrate the skin on a sunny day. Daily exposure of differentiated adipocytes to blue light resulted in decreased lipid droplet size, increased basal lipolytic rate and alterations in adiponectin and leptin secretion. Our results suggest that scWAT function may be directly under the influence of ambient sunlight exposure and may have important implications for our current understanding of adipocyte biology. (150 words)
Collapse
|
7
|
Xu YJ, Elimban V, Dhalla NS. Reduction of blood pressure by store-operated calcium channel blockers. J Cell Mol Med 2015; 19:2763-70. [PMID: 26471725 PMCID: PMC4687696 DOI: 10.1111/jcmm.12684] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 08/14/2015] [Indexed: 12/16/2022] Open
Abstract
The voltage-operated Ca(2+) channels (VOCC), which allow Ca(2+) influx from the extracellular space, are inhibited by anti-hypertensive agents such as verapamil and nifedipine. The Ca(2+) entering from outside into the cell triggers Ca(2+) release from the sarcoplasmic reticulum (SR) stores. To refill the depleted Ca(2+) stores in the SR, another type of Ca(2+) channels in the cell membrane, known as store-operated Ca(2+) channels (SOCC), are activated. These SOCCs are verapamil and nifedipine resistant, but are SKF 96465 (SK) and gadolinium (Gd(3+) ) sensitive. Both SK and Gd(3+) have been shown to reduce [Ca(2+) ]i in the smooth muscle, but their effects on blood pressure have not been reported. Our results demonstrated that both SK and Gd(3+) produced a dose-dependent reduction in blood pressure in rat. The combination of SK and verapamil produced an additive action in lowering the blood pressure. Furthermore, SK, but not Gd(3+) suppressed proliferation of vascular smooth muscle cells in the absence or presence of lysophosphatidic acid (LPA). SK decreased the elevation of [Ca(2+) ]i induced by LPA, endothelin-1 (ET-1) and angiotensin II (Ang II), but did not affect the norepinephrine (NE)-evoked increase in [Ca(2+) ]i . On the other hand, Gd(3+) inhibited the LPA and Ang II induced change in [Ca(2+) ]i , but had no effect on the ET-1 and NE induced increase in [Ca(2+) ]i . The combination of verapamil and SK abolished the LPA- or adenosine-5'-triphosphate (ATP)-induced [Ca(2+) ]i augmentation. These results suggest that SOCC inhibitors, like VOCC blocker, may serve as promising drugs for the treatment of hypertension.
Collapse
Affiliation(s)
- Yan-Jun Xu
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, Department of Physiology and Pathophysiology, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Vijayan Elimban
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, Department of Physiology and Pathophysiology, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Naranjan S Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, Department of Physiology and Pathophysiology, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
8
|
Becker EBE. The Moonwalker mouse: new insights into TRPC3 function, cerebellar development, and ataxia. THE CEREBELLUM 2015; 13:628-36. [PMID: 24797279 PMCID: PMC4155175 DOI: 10.1007/s12311-014-0564-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The Moonwalker (Mwk) mouse is a recent model of dominantly inherited cerebellar ataxia. The motor phenotype of the Mwk mouse is due to a gain-of-function mutation in the gene encoding the cation-permeable transient receptor potential channel (TRPC3). This mutation converts a threonine into an alanine in the highly conserved cytoplasmic S4–S5 linker of the channel, affecting channel gating. TRPC3 is highly expressed in cerebellar Purkinje cells and type II unipolar brush cells that both degenerate in the Mwk mouse. Studies of the Mwk mouse have provided new insights into the role of TRPC3 in cerebellar development and disease, which could not have been predicted from the Trpc3 knockout phenotype. Here, the genetic, behavioral, histological, and functional characterization of the Mwk mouse is reviewed. Moreover, the relationship of the Mwk mutant to other cerebellar mouse models and its relevance as a model for cerebellar ataxia are discussed.
Collapse
Affiliation(s)
- Esther B E Becker
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3PT, UK,
| |
Collapse
|
9
|
Zhang E, Liao P. Brain transient receptor potential channels and stroke. J Neurosci Res 2014; 93:1165-83. [PMID: 25502473 DOI: 10.1002/jnr.23529] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 09/10/2014] [Accepted: 11/04/2014] [Indexed: 02/06/2023]
Abstract
Transient receptor potential (TRP) channels have been increasingly implicated in the pathological mechanisms of CNS disorders. TRP expression has been detected in neurons, astrocytes, oligodendrocytes, microglia, and ependymal cells as well as in the cerebral vascular endothelium and smooth muscle. In stroke, TRPC3/4/6, TRPM2/4/7, and TRPV1/3/4 channels have been found to participate in ischemia-induced cell death, whereas other TRP channels, in particular those expressed in nonneuronal cells, have been less well studied. This review summarizes the current knowledge on the expression and functions of the TRP channels in various cell types in the brain and our current understanding of TRP channels in stroke pathophysiology. In an aging society, the occurrence of stroke is expected to increase steadily, and there is an urgent requirement to improve the current stroke management strategy. Therefore, elucidating the roles of TRP channels in stroke could shed light on the development of novel therapeutic strategies and ultimately improve stroke outcome.
Collapse
Affiliation(s)
- Eric Zhang
- Calcium Signalling Laboratory, National Neuroscience Institute, Singapore
| | - Ping Liao
- Calcium Signalling Laboratory, National Neuroscience Institute, Singapore.,Duke-NUS Graduate Medical School Singapore, Singapore
| |
Collapse
|
10
|
McPate M, Bhalay G, Beckett M, Fairbrother S, Gosling M, Groot-Kormelink PJ, Lane R, Kent T, Van Diepen MT, Tranter P, Verkuyl JM. The Development of Automated Patch Clamp Assays for Canonical Transient Receptor Potential Channels TRPC3, 6, and 7. Assay Drug Dev Technol 2014; 12:282-92. [PMID: 24906109 DOI: 10.1089/adt.2014.574] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Mark McPate
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Gurdip Bhalay
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Martin Beckett
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Sian Fairbrother
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Martin Gosling
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Paul J. Groot-Kormelink
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Rebecca Lane
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Toby Kent
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Michiel T. Van Diepen
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - Pamela Tranter
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| | - J. Martin Verkuyl
- Novartis Institutes for BioMedical Research, Horsham Research Centre, West Sussex, United Kingdom
| |
Collapse
|
11
|
Zhou FM, Lee CR. Intrinsic and integrative properties of substantia nigra pars reticulata neurons. Neuroscience 2011; 198:69-94. [PMID: 21839148 PMCID: PMC3221915 DOI: 10.1016/j.neuroscience.2011.07.061] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 07/07/2011] [Accepted: 07/14/2011] [Indexed: 11/27/2022]
Abstract
The GABA projection neurons of the substantia nigra pars reticulata (SNr) are output neurons for the basal ganglia and thus critical for movement control. Their most striking neurophysiological feature is sustained, spontaneous high frequency spike firing. A fundamental question is: what are the key ion channels supporting the remarkable firing capability in these neurons? Recent studies indicate that these neurons express tonically active type 3 transient receptor potential (TRPC3) channels that conduct a Na-dependent inward current even at hyperpolarized membrane potentials. When the membrane potential reaches -60 mV, a voltage-gated persistent sodium current (I(NaP)) starts to activate, further depolarizing the membrane potential. At or slightly below -50 mV, the large transient voltage-activated sodium current (I(NaT)) starts to activate and eventually triggers the rapid rising phase of action potentials. SNr GABA neurons have a higher density of I(NaT), contributing to the faster rise and larger amplitude of action potentials, compared with the slow-spiking dopamine neurons. I(NaT) also recovers from inactivation more quickly in SNr GABA neurons than in nigral dopamine neurons. In SNr GABA neurons, the rising phase of the action potential triggers the activation of high-threshold, inactivation-resistant Kv3-like channels that can rapidly repolarize the membrane. These intrinsic ion channels provide SNr GABA neurons with the ability to fire spontaneous and sustained high frequency spikes. Additionally, robust GABA inputs from direct pathway medium spiny neurons in the striatum and GABA neurons in the globus pallidus may inhibit and silence SNr GABA neurons, whereas glutamate synaptic input from the subthalamic nucleus may induce burst firing in SNr GABA neurons. Thus, afferent GABA and glutamate synaptic inputs sculpt the tonic high frequency firing of SNr GABA neurons and the consequent inhibition of their targets into an integrated motor control signal that is further fine-tuned by neuromodulators including dopamine, serotonin, endocannabinoids, and H₂O₂.
Collapse
Affiliation(s)
- F-M Zhou
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, TN 38163, USA.
| | | |
Collapse
|
12
|
Harteneck C, Gollasch M. Pharmacological modulation of diacylglycerol-sensitive TRPC3/6/7 channels. Curr Pharm Biotechnol 2011; 12:35-41. [PMID: 20932261 PMCID: PMC3267170 DOI: 10.2174/138920111793937943] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 05/13/2010] [Indexed: 01/03/2023]
Abstract
Members of the classic type of transient receptor potential channels (TRPC) represent important molecules involved in hormonal signal transduction. TRPC3/6/7 channels are of particular interest as they are components of phospholipase C driven signalling pathways. Upon receptor-activation, G-protein-mediated stimulation of phospholipase C results in breakdown of phosphatidylinositides leading to increased intracellular diacylglycerol and inositol-trisphosphate levels. Diacylglycerol activates protein kinase C, but more interestingly diacylglycerol directly activates TRPC2/3/6/7 channels. Molecular cloning, expression and characterization of TRP channels enabled reassignment of traditional inhibitors of receptor-dependent calcium entry such as SKF-96365 and 2-APB as blockers of TRPC3/6/7 and several members of non-classic TRP channels. Furthermore, several enzyme inhibitors have also been identified as TRP channel blockers, such as ACA, a phospholipase A2 inhibitor, and W-7, a calmodulin antagonist. Finally, the naturally occurring secondary plant compound hyperforin has been identified as TRPC6-selective drug, providing an exciting proof of concept that it is possible to generate TRPC-selective channel modulators. The description of Pyr3 as the first TRPC3-selective inhibitor shows that not only nature but also man is able to generate TRP-selective modulators. The review sheds lights on the current knowledge and historical development of pharmacological modulators of TRPC3/6/7. Our analysis indicates that Pyr3 and hyperforin provide promising core structures for the development of new, selective and more potent modulators of TRPC3/6/7 activity.
Collapse
Affiliation(s)
- Christian Harteneck
- Institut für Pharmakologie & Toxikologie, Eberhard-Karls-Universitát, Wilhelmstraße 56, 72074 Tübingen, Germany.
| | | |
Collapse
|
13
|
Trebak M. The puzzling role of TRPC3 channels in motor coordination. Pflugers Arch 2009; 459:369-75. [PMID: 19823866 DOI: 10.1007/s00424-009-0740-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Revised: 09/16/2009] [Accepted: 09/20/2009] [Indexed: 11/25/2022]
Abstract
Transient receptor potential canonical 3 (TRPC3) proteins are nonselective cation channels activated downstream of phospholipase-C-coupled receptors. TRPC3 channels have emerged as major players in the function of the central nervous system. They have been described as important contributors to brain-derived neurotrophic factor mediated survival and growth-cone guidance of cerebellar granule neurons. TRPC3 were also identified as postsynaptic cation channels essential for metabotropic glutamate receptor1-dependent synaptic transmission in cerebellar Purkinje neurons. A recent report described motor coordination defects in TRPC3 knockout mice while a subsequent study reported a similar phenotype in so-called moonwalker mice, harboring a TRPC3 gain-of-function mutation. How can opposing aspects of TRPC3 channel activation lead to the same phenotype? Here we discuss the salient features of TRPC3 knockout mice and moonwalker mice and attempt to reconcile the apparently conflicting findings from these two animal models.
Collapse
Affiliation(s)
- Mohamed Trebak
- The Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Ave, MC8, Albany, NY 12208, USA.
| |
Collapse
|
14
|
McElroy SP, Drummond RM, Gurney AM. Regulation of store-operated Ca2+ entry in pulmonary artery smooth muscle cells. Cell Calcium 2009; 46:99-106. [DOI: 10.1016/j.ceca.2009.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 05/05/2009] [Accepted: 05/31/2009] [Indexed: 11/25/2022]
|
15
|
A point mutation in TRPC3 causes abnormal Purkinje cell development and cerebellar ataxia in moonwalker mice. Proc Natl Acad Sci U S A 2009; 106:6706-11. [PMID: 19351902 DOI: 10.1073/pnas.0810599106] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The hereditary ataxias are a complex group of neurological disorders characterized by the degeneration of the cerebellum and its associated connections. The molecular mechanisms that trigger the loss of Purkinje cells in this group of diseases remain incompletely understood. Here, we report a previously undescribed dominant mouse model of cerebellar ataxia, moonwalker (Mwk), that displays motor and coordination defects and loss of cerebellar Purkinje cells. Mwk mice harbor a gain-of-function mutation (T635A) in the Trpc3 gene encoding the nonselective transient receptor potential cation channel, type C3 (TRPC3), resulting in altered TRPC3 channel gating. TRPC3 is highly expressed in Purkinje cells during the phase of dendritogenesis. Interestingly, growth and differentiation of Purkinje cell dendritic arbors are profoundly impaired in Mwk mice. Our findings define a previously unknown role for TRPC3 in both dendritic development and survival of Purkinje cells, and provide a unique mechanism underlying cerebellar ataxia.
Collapse
|
16
|
TRPC3 protein is expressed across the lifespan in human prefrontal cortex and cerebellum. Brain Res 2009; 1260:1-6. [DOI: 10.1016/j.brainres.2008.12.069] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 12/16/2008] [Accepted: 12/27/2008] [Indexed: 02/05/2023]
|
17
|
Hirschler-Laszkiewicz I, Tong Q, Conrad K, Zhang W, Flint WW, Barber AJ, Barber DL, Cheung JY, Miller BA. TRPC3 activation by erythropoietin is modulated by TRPC6. J Biol Chem 2009; 284:4567-81. [PMID: 19074769 PMCID: PMC2640975 DOI: 10.1074/jbc.m804734200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 12/09/2008] [Indexed: 11/06/2022] Open
Abstract
Regulation of intracellular calcium ([Ca(2+)](i)) by erythropoietin (Epo) is an essential part of signaling pathways controlling proliferation and differentiation of erythroid progenitors, but regulatory mechanisms are largely unknown. TRPC3 and the homologous TRPC6 are two members of the transient receptor potential channel (TRPC) superfamily that are expressed on normal human erythroid precursors. Here we show that TRPC3 expression increases but TRPC6 decreases during erythroid differentiation. This is associated with a significantly greater increase in [Ca(2+)](i) in response to Epo stimulation, suggesting that the ratio of TRPC3/TRPC6 is physiologically important. In HEK 293T cells heterologously expressing TRPC and erythropoietin receptor (Epo-R), Epo stimulated an increase in [Ca(2+)](i) through TRPC3 but not TRPC6. Replacement of the C terminus of TRPC3 with the TRPC6 C terminus (TRPC3-C6C) resulted in loss of activation by Epo. In contrast, substitution of the C terminus of TRPC6 with that of TRPC3 (TRPC6-C3C) resulted in an increase in [Ca(2+)](i) in response to Epo. Substitution of the N termini had no effect. Domains in the TRPC3 C terminus between amino acids 671 and 746 are critical for the response to Epo. Epo-R and phospholipase Cgamma associated with TRPC3, and these interactions were significantly reduced with TRPC6 and TRPC3-C6C chimeras. TRPC3 and TRPC6 form heterotetramers. Coexpression of TRPC6 or C3/C6 chimeras with TRPC3 and Epo-R inhibited the Epo-stimulated increase in [Ca(2+)](i). In a heterologous expression system, Epo stimulation increased cell surface expression of TRPC3, which was inhibited by TRPC6. However, in primary erythroblasts, an increase in TRPC3 cell surface expression was not observed in erythroblasts in which Epo stimulated an increase in [Ca(2+)](i), demonstrating that increased membrane insertion of TRPC3 is not required. These data demonstrate that TRPC6 regulates TRPC3 activation by Epo. Endogenously, regulation of TRPC3 by TRPC6 may primarily be through modulation of signaling mechanisms, including reduced interaction of TRPC6 with phospholipase Cgamma and Epo-R.
Collapse
Affiliation(s)
- Iwona Hirschler-Laszkiewicz
- Department of Pediatrics, the Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Vassort G, Alvarez J. Transient receptor potential: a large family of new channels of which several are involved in cardiac arrhythmiaThis article is one of a selection of papers from the NATO Advanced Research Workshop on Translational Knowledge for Heart Health (published in part 1 of a 2-part Special Issue). Can J Physiol Pharmacol 2009; 87:100-7. [DOI: 10.1139/y08-112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The transient receptor potential (TRP) family of ion channels comprises more than 50 cation-permeable channels expressed throughout the animal kingdom. TRPs can be grouped into 7 main subfamilies according to structural homology: the TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin), TRPML (mucolipin), TRPA (ankyrin), and TRPN (NO mechanopotential). During the past 20 years, the cloning and characterization after reexpression of most members of these cation channels have led to a plethora of data and more recently to some understanding of their roles in various cells and tissues. Specifically in the heart, TRPs are known to be involved in various diseases, including hypertrophy, heart failure, and arrhythmia. The later part of this review focuses on the potential contribution of TRPs to cardiac rhythm and their potential proarrhythmic effects. Furthermore, several neurotransmitters that activate the formation of diacylglycerol could modulate cardiac rhythm or, like ATP, induce arrhythmia.
Collapse
Affiliation(s)
- Guy Vassort
- INSERM U-637 Physiopathologie cardiovasculaire, CHU Arnaud de Villeneuve, Montpellier Cedex 05, 34295 France
- Laboratorio de Electrofisiologia, Instituto de Cardiologia, La Habana 10400, Cuba
| | - Julio Alvarez
- INSERM U-637 Physiopathologie cardiovasculaire, CHU Arnaud de Villeneuve, Montpellier Cedex 05, 34295 France
- Laboratorio de Electrofisiologia, Instituto de Cardiologia, La Habana 10400, Cuba
| |
Collapse
|
19
|
Poteser M, Graziani A, Eder P, Yates A, Mächler H, Romanin C, Groschner K. Identification of a rare subset of adipose tissue-resident progenitor cells, which express CD133 and TRPC3 as a VEGF-regulated Ca2+ entry channel. FEBS Lett 2008; 582:2696-702. [PMID: 18602918 DOI: 10.1016/j.febslet.2008.06.049] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 06/16/2008] [Accepted: 06/26/2008] [Indexed: 11/30/2022]
Abstract
VEGF-induced Ca2+ signalling was investigated in CD133+/VEGFR-2+ progenitor cells isolated from human adipose stroma. Colonies derived from CD133+ immunoselected cells displayed inhomogenous Ca2+ signals, with variable magnitude of VEGF-induced Ca2+ entry, which positively correlated with expression of the Ca2+ channel protein TRPC3. High levels of VEGF-induced Ca2+ entry and TRPC3 expression were preferentially detected in rim areas of expanding colonies. Dominant negative suppression of TRPC3 inhibited VEGF-induced Ca2+ entry into CD133+ cells. Our results identify TRPC3 as a key Ca2+ entry channel in a subset of CD133+ stem cells. We suggest TRPC3 as an essential determinant of cell fate in CD133+ progenitor-derived colonies.
Collapse
Affiliation(s)
- Michael Poteser
- Institute of Pharmaceutical Sciences, Pharmacology and Toxicology, Karl-Franzens-University of Graz, Graz, Austria
| | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
Transient receptor potential (TRP) channels are important in many neuronal and non-neuronal physiological processes. The past 2 years have seen much progress in the use of structural biology techniques to elucidate molecular mechanisms of TRP channel gating and regulation. Two approaches have proven fruitful: (i) a divide-and-conquer strategy has provided high-resolution structural details of TRP channel fragments although it fails to explain how these fragments are integrated in the full channel; and (ii) electron microscopy of entire TRP channels has yielded low-resolution images that provide a basis for testable models of TRP channel architecture. The results of each approach, summarized in this review, provide a preview of what the future holds in TRP channel structural biology.
Collapse
Affiliation(s)
- Rachelle Gaudet
- Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 01238, USA.
| |
Collapse
|
21
|
|
22
|
Lockwich T, Pant J, Makusky A, Jankowska-Stephens E, Kowalak JA, Markey SP, Ambudkar IS. Analysis of TRPC3-interacting proteins by tandem mass spectrometry. J Proteome Res 2008; 7:979-89. [PMID: 18205297 DOI: 10.1021/pr070496k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mammalian transient receptor potential canonical (TRPC) channels are a family of nonspecific cation channels that are activated in response to stimulation of phospholipase C (PLC)-dependent hydrolysis of the membrane lipid phosphatidylinositol 4,5-bisphosphate. Despite extensive studies, the mechanism(s) involved in regulation of mammalian TRPC channels remains unknown. Presence of various protein-interacting domains in TRPC channels have led to the suggestion that they associate with proteins that are involved in their function and regulation. This study was directed toward identifying the proteins associated with native TRPC3 using a shotgun proteomic approach. Anti-TRPC3 antibody was used to immunoprecipitate TRPC3 from solubilized rat brain crude membranes under conditions that allow retention of TRPC3 function. Proteins in the TRPC3 (using anti-TRPC3 antibody) and control (using rabbit IgG) immunoprecipitates were separated by SDS-PAGE, the gel was sectioned, and the resolved proteins were digested by trypsin in situ. After extraction of the peptides, the peptides were separated by HPLC and sequences derived by MS/MS. Analysis of the data revealed 64 specific TRPC3-associated proteins which can be grouped in terms of their cellular location and involvement in specific cellular function. Many of the proteins identified have been previously reported as TRPC3-regulatory proteins, such as IP3Rs and vesicle trafficking proteins. In addition, we report novel putative TRPC3-interacting proteins, including those involved in protein endocytosis and neuronal growth. To our knowledge, this is the first comprehensive proteomic analysis of a native TRPC channel. These data reveal potential TRPC3 regulatory proteins and provide novel insights of the mechanism(s) regulating TRPC3 channels as well as the possible cellular functions where the channel might be involved.
Collapse
Affiliation(s)
- Timothy Lockwich
- Secretory Physiology Section, Molecular Physiology and Therapeutics Branch, NIDCR, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | | | | | |
Collapse
|
23
|
Dietrich A, Kalwa H, Fuchs B, Grimminger F, Weissmann N, Gudermann T. In vivo TRPC functions in the cardiopulmonary vasculature. Cell Calcium 2007; 42:233-44. [PMID: 17433435 DOI: 10.1016/j.ceca.2007.02.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 02/07/2007] [Accepted: 02/08/2007] [Indexed: 12/01/2022]
Abstract
Cardiovascular diseases are the leading cause of death in the industrialized countries. The cardiovascular system includes the systemic blood circulation, the heart and the pulmonary circulation providing sufficient blood flow and oxygen to peripheral tissues and organs according to their metabolic demand. This review focuses on three major cell types of the cardiovascular system: myocytes of the heart as well as smooth muscle cells and endothelial cells from the systemic and pulmonary circulation. Ion channels initiate and regulate contraction in all three cell types, and the identification of their genes has significantly improved our knowledge of signal transduction pathways in these cells. Among the ion channels expressed in smooth muscle cells, cation channels of the TRPC family allow for the entry of Na(+) and Ca(2+). Physiological functions of TRPC1, TRPC3, TRPC4, TRPC5, TRPC6 and TRPC7 in the cardiovascular system, dissected by down-regulating channel activity in isolated tissues or by the analysis of gene-deficient mouse models, are reviewed. Possible functional roles and physiological regulation of TRPCs as homomeric or heteromeric channels in these cell types are discussed. Moreover, TRP channels may also be responsible for pathophysiological processes of the cardiovascular system like hypertension as well as cardiac hypertrophy and increased endothelial permeability.
Collapse
MESH Headings
- Animals
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiology
- Heart Diseases/etiology
- Humans
- Hypertension/etiology
- Mice
- Muscle Contraction
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/physiology
- Pulmonary Circulation
- Rats
- TRPC Cation Channels/physiology
Collapse
Affiliation(s)
- Alexander Dietrich
- Institute for Pharmacology and Toxicology, School of Medicine, University of Marburg, 35043 Marburg, Germany.
| | | | | | | | | | | |
Collapse
|