Abstract 138: Transient Receptor Potential Channel C1 Deficiency Protects the Murine Heart from Pressure Overload

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Malini Seth ◽  
Zhu-Shan Zhang ◽  
Lan Mao ◽  
Jarrett Burch ◽  
Victoria Graham ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Transient Receptor Potential ◽  
Pressure Overload ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Trpc Channels ◽  
Loss Of Function ◽  
Aortic Banding ◽  
Trpc1 Channels ◽  
Transient Receptor

Transient receptor potential canonical (TRPC) channels are non-selective cation channels that are activated in response to G-protein coupled receptor activation, depletion of internal stores and mechanical stretch. Recent reports suggest that cardiac TRPC channels mediate calcineurin dependent cardiac hypertrophy, yet few details exist as to the mechanism for activation of these channels. Here, we provide evidence that TRPC1 channels are the dominant TRPC channel in mouse cardiomyocytes and cardiac TRPC1 protein expression is augmented by seven fold following thoracic aortic banding (TAC). In addition, we provide the first loss of function studies to show that mice lacking TRPC1 channels developed significantly less cardiac hypertrophy following pressure overload induced by thoracic aortic banding suggesting that TRPC1 may confer deleterious calcium entry. Whole cell voltage clamp studies of isolated adult cardiomyocytes reveal a non-selective cation current that is induced by pressure overload that is absent in TRPC1−/− cardiomyocytes and in which TRP blockers such as gadolinium, 2-amino biphenyl boric acid and SKF96365 inhibit the TAC induced current. Finally, neonatal cardiomyocytes lacking functional TRPC1 display reduced TRPC current in response to cell stretch or angiotensin-II; the functional consequence of which includes reduced calcium oscillation frequency and reduced BNP expression. These results provide the first loss of function evidence for TRPC1 channels in cardiac hypertrophy and implicate TRPC1 as a stretch activated channel.

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

2008 ◽  
Vol 19 (8) ◽  
pp. 3203-3211 ◽  
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.

Abstract 164: Microdomain Specific Effects of Transient Receptor Potential Channels on Pathological Cardiac Hypertrophy and Myocyte Contractility

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Catherine A Makarewich ◽  
Hongyu Zhang ◽  
Hui Gao ◽  
Robert N Correll ◽  
Jason M Duran ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Trpc Channels ◽  
Ec Coupling ◽  
Transient Receptor ◽  
Myocyte Contractility ◽  
Signaling Domains ◽  
Ca2 Channels

Hypothesis: Ca2+ influx through transient receptor potential canonical (TRPC) channels and L-type Ca2+ channels (LTCCs) within caveolin-3 (Cav3) stabilized signaling microdomains provide a unique source of Ca2+ to activate pathologic cardiac hypertrophy through calcineurin (Cn)-mediated nuclear factor of activated T-cells (NFAT) signaling. We suggest that a distinct and separate population of TRPC channels localized in excitation-contraction (EC) coupling microdomains may have potent effects on myocyte contractility independent of Cav3 signaling domains. Methods and Results: Membrane localization studies and immunohistochemistry show that TRPC channels and LTCCs co-localize to Cav3 signaling microdomains. To explore a role for these caveolae based Ca2+ channels in the initiation of Cn-NFAT signaling we used an adenoviral NFAT-GFP reporter in cultured adult feline myocytes (AFMs). Infecting AFMs with ad-TRPC3 dramatically increased NFAT translocation, which was inhibited with dominant negative ad-dnTRPC6. Expression of a Cav3 targeted LTCC blocker (ad-Cav-Rem) reduced NFAT translocation while a targeted LTCC activator (ad-Cav-β2a) significantly increased NFAT activation. Neither LTCC modulator had significant effects on Ca2+ current or contractility in AFMs but we found that the expression of TRPC3 reduced myocyte contractility and induced spontaneous Ca2+ spark activity that was exacerbated by the DAG activator OAG. Moreover, dnTRPC6 blocked spontaneous Ca2+ sparks even in the presence of OAG. Immunohistochemistry analysis revealed the presence of TRPC channels in transverse tubules, consistent with the idea that they could have direct effects on EC coupling microdomains. Conclusions: Our data show that TRPC channels and LTCCs co-localize to Cav3 signaling domains where they generate a unique Ca2+ microenvironment that directly regulates Cn-NFAT signaling. Our findings also suggest that a separate and distinct population of TRPC channels within EC coupling microdomains cause reduced myocyte contractility by inducing SR Ca2+ leak and Ca2+ spark activity.

scholarly journals Emerging Roles of Diacylglycerol-Sensitive TRPC4/5 Channels

Cells ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 218 ◽  
Author(s):  
Michael Mederos y Schnitzler ◽  
Thomas Gudermann ◽  
Ursula Storch
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Activation Mechanism ◽  
Regulatory Function ◽  
Cation Channels ◽  
Trpc Channels ◽  
Trpc Channel ◽  
Transient Receptor ◽  
Trpc5 Channels

Transient receptor potential classical or canonical 4 (TRPC4) and TRPC5 channels are members of the classical or canonical transient receptor potential (TRPC) channel family of non-selective cation channels. TRPC4 and TRPC5 channels are widely accepted as receptor-operated cation channels that are activated in a phospholipase C-dependent manner, following the Gq/11 protein-coupled receptor activation. However, their precise activation mechanism has remained largely elusive for a long time, as the TRPC4 and TRPC5 channels were considered as being insensitive to the second messenger diacylglycerol (DAG) in contrast to the other TRPC channels. Recent findings indicate that the C-terminal interactions with the scaffolding proteins Na+/H+ exchanger regulatory factor 1 and 2 (NHERF1 and NHERF2) dynamically regulate the DAG sensitivity of the TRPC4 and TRPC5 channels. Interestingly, the C-terminal NHERF binding suppresses, while the dissociation of NHERF enables, the DAG sensitivity of the TRPC4 and TRPC5 channels. This leads to the assumption that all of the TRPC channels are DAG sensitive. The identification of the regulatory function of the NHERF proteins in the TRPC4/5-NHERF protein complex offers a new starting point to get deeper insights into the molecular basis of TRPC channel activation. Future studies will have to unravel the physiological and pathophysiological functions of this multi-protein channel complex.

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

2009 ◽  
Vol 101 (3) ◽  
pp. 1151-1159 ◽  
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.

scholarly journals Mineralocorticoid receptor antagonism improves parenchymal arteriole dilation via a TRPV4-dependent mechanism and prevents cognitive dysfunction in hypertension

2018 ◽  
Vol 315 (5) ◽  
pp. H1304-H1315 ◽  
Author(s):  
Janice M. Diaz-Otero ◽  
Ting-Chieh Yen ◽  
Courtney Fisher ◽  
Daniel Bota ◽  
William F. Jackson ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Angiotensin Ii ◽  
Mineralocorticoid Receptor ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Myogenic Tone ◽  
Transient Receptor Potential Vanilloid ◽  
Cerebrovascular Function ◽  
Transient Receptor

Hypertension and mineralocorticoid receptor activation cause cerebral parenchymal arteriole remodeling; this can limit cerebral perfusion and contribute to cognitive dysfunction. We used a mouse model of angiotensin II-induced hypertension to test the hypothesis that mineralocorticoid receptor activation impairs both transient receptor potential vanilloid (TRPV)4-mediated dilation of cerebral parenchymal arterioles and cognitive function. Mice (16−18 wk old, male, C57Bl/6) were treated with angiotensin II (800 ng·kg−1·min−1) with or without the mineralocorticoid receptor antagonist eplerenone (100 mg·kg−1·day−1) for 4 wk; sham mice served as controls. Data are presented as means ± SE; n = 5–14 mice/group. Eplerenone prevented the increased parenchymal arteriole myogenic tone and impaired carbachol-induced (10−9–10−5 mol/l) dilation observed during hypertension. The carbachol-induced dilation was endothelium-derived hyperpolarization mediated because it could not be blocked by N-nitro-l-arginine methyl ester (10−5 mol/l) and indomethacin (10−4 mol/l). We used GSK2193874 (10−7 mol/l) to confirm that in all groups this dilation was dependent on TRPV4 activation. Dilation in response to the TRPV4 agonist GSK1016790A (10−9–10−5 mol/l) was also reduced in hypertensive mice, and this defect was corrected by eplerenone. In hypertensive and eplerenone-treated animals, TRPV4 inhibition reduced myogenic tone, an effect that was not observed in arterioles from control animals. Eplerenone treatment also improved cognitive function and reduced microglia density in hypertensive mice. These data suggest that the mineralocorticoid receptor is a potential therapeutic target to improve cerebrovascular function and cognition during hypertension. NEW & NOTEWORTHY Vascular dementia is a growing public health issue that lacks effective treatments. Transient receptor potential vanilloid (TRPV)4 channels are important regulators of parenchymal arteriole dilation, and they modulate myogenic tone. The data presented here suggest that TRPV4 channel expression is regulated by the mineralocorticoid receptor (MR). MR blockade also improves cognitive function during hypertension. MR blockade might be a potential therapeutic approach to improve cerebrovascular function and cognition in patients with hypertension.

Abstract 18822: Endoglin Selectively Modulates TRPC Expression in Response to Left or Right Ventricular Pressure Overload

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Kevin J Morine ◽  
Vikram Paruchuri ◽  
Xiaoying Qiao ◽  
Duc T Pham ◽  
Gordon S Huggins ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Cardiac Fibrosis ◽  
Transient Receptor Potential ◽  
Transforming Growth Factor ◽  
Pressure Overload ◽  
Receptor Potential ◽  
Left Ventricular ◽  
Transient Receptor ◽  
Novel Target ◽  
The Right

Introduction: Endoglin is an accessory receptor for the cytokine transforming growth factor beta. Reduced endoglin activity limits cardiac fibrosis due to left ventricular (LV) pressure overload. Recently, we reported that reducing endoglin activity also limits upregulation of the profibrogenic transient receptor potential canonical channel 6 (TRPC6) in the right ventricle (RV) during pressure overload. Few studies have compared TRPC channel expression in the RV versus LV. Hypothesis: We hypothesized that endoglin regulates TRPC upregulation in response to RV and LV pressure overload. Methods: To explore a functional role for endoglin as a regulator of TRPC expression in response to RV or LV pressure overload, endoglin haploinsufficient (Eng+/-) and wild-type (Eng+/+) mice were exposed to thoracic aortic (TAC) or pulmonary arterial (PAC) constriction for 10 weeks. Biventricular tissue was then analyzed by real-time polymerase chain reaction. Results: After TAC, LV levels of TPRC1 and 6 were increased in both Eng +/+ and Eng +/- mice compared to sham controls. LV levels of TRPC4 were increased in Eng +/+, not Eng +/- mice after TAC. After PAC, RV levels of TRPC1, 3, 4, and 6 were increased in Eng +/+ compared to sham controls. In contrast, chronic RV pressure overload did not increase RV levels of TRPC1, 3, 4, and 6 in Eng +/- mice compared to sham controls. Conclusions: Pressure overload induces distinct profiles of TRPC expression in the RV and LV and these effects in the RV require full endoglin activity. Taken together, these data support that endoglin may be an important and novel target of therapy to modulate RV responses to injury.

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

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.

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

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
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.

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

Cells ◽  
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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