Distance constraints on activation of TRPV4 channels by AKAP150-bound PKCα in arterial myocytes.
Ontology highlight
ABSTRACT:
SUBMITTER: Tajada S
PROVIDER: S-EPMC5460949 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Transient receptor potential vanilloid 4 (TRPV4) channels are Ca(2+)-permeable, nonselective cation channels expressed in multiple tissues, including smooth muscle. Although TRPV4 channels play a key role in regulating vascular tone, the mechanisms controlling Ca(2+) influx through these channels in arterial myocytes are poorly understood. Here, we tested the hypothesis that in arterial myocytes the anchoring protein AKAP150 and protein kinase C (PKC) play a critical role in the regulation of TRPV4 channels during angiotensin II (AngII) signaling. Super-resolution imaging revealed that TRPV4 channels are gathered into puncta of variable sizes along the sarcolemma of arterial myocytes. Recordings of Ca(2+) entry via single TRPV4 channels ("TRPV4 sparklets") suggested that basal TRPV4 sparklet activity was low. However, Ca(2+) entry during elementary TRPV4 sparklets was ∼ 100-fold greater than that during L-type CaV1.2 channel sparklets. Application of the TRPV4 channel agonist GSK1016790A or the vasoconstrictor AngII increased the activity of TRPV4 sparklets in specific regions of the cells. PKC and AKAP150 were required for AngII-induced increases in TRPV4 sparklet activity. AKAP150 and TRPV4 channel interactions were dynamic; activation of AngII signaling increased the proximity of AKAP150 and TRPV4 puncta in arterial myocytes. Furthermore, local stimulation of diacylglycerol and PKC signaling by laser activation of a light-sensitive Gq-coupled receptor (opto-α1AR) resulted in TRPV4-mediated Ca(2+) influx. We propose that AKAP150, PKC, and TRPV4 channels form dynamic subcellular signaling domains that control Ca(2+) influx into arterial myocytes.
| S-EPMC4003184 | biostudies-literature
Project description:The mechanosensitive ion channels Transient Receptor Potential Vanilloid 4 (TRPV4) and PIEZO1 transduce physiologic and supraphysiologic magnitudes of mechanical signals in the chondrocyte, respectively. TRPV4 activation promotes chondrogenesis, while PIEZO1 activation by supraphysiologic deformations drives cell death. The mechanisms by which activation of these channels discretely drives changes in gene expression to alter cell behavior remains to be determined. To date, no studies have contrasted the transcriptomic response to activation of these channels, nor has any published data attempted to correlate these transcriptomes to alterations in cellular function. This study used RNA sequencing to comprehensively investigate the transcriptomes associated with activation of TRPV4 or PIEZO1, revealing that TRPV4 and PIEZO drive distinct transcriptomes, but also exhibit unique co-regulated clusters of genes. Notably, activation of PIEZO1 through supraphysiologic deformation induced a transient inflammatory profile that overlapped with the interleukin (IL)-1-responsive transcriptome and contained genes associated with cartilage degradation and osteoarthritis progression. However, both TRPV4 and PIEZO1 were also shown to elicit anabolic effects. PIEZO1 expression promoted a pro-chondrogenic transcriptome under unloaded conditions, and daily treatment with PIEZO1 agonist Yoda1 significantly increased sulfated glycosaminoglycan deposition in vitro. These findings emphasize the presence of a broad “mechanome” with distinct effects of TRPV4 and PIEZO1 activation in chondrocytes, suggesting complex roles for PIEZO1 in both the physiologic and pathologic responses of chondrocytes. The identification of transcriptomic profiles unique to or shared by PIEZO1 and TRPV4 (distinct from IL-1-induced inflammation) could inform future therapeutic designs targeting these channels for the management and treatment of osteoarthritis.
2024-06-05 | GSE269159 | GEO
Project description:TRPV4 is a non-selective cation channel that tunes the function of different tissues including the vascular endothelium, lung, chondrocytes, and neurons. GSK1016790A is the selective and potent agonist of TRPV4 and a pharmacological tool that is used to study the TRPV4 physiological function in vitro and in vivo. It remains unknown how the sensitivity of TRPV4 to this agonist is regulated. The spatial and temporal dynamics of receptors are the major determinants of cellular responses to stimuli. Membrane translocation has been shown to control the response of several members of the transient receptor potential (TRP) family of ion channels to different stimuli. Here, we show that TRPV4 stimulation with GSK1016790A caused an increase in [Ca2+]i that is stable for a few minutes. Single molecule analysis of TRPV4 channels showed that the density of TRPV4 at the plasma membrane is controlled through two modes of membrane trafficking, complete, and partial vesicular fusion. Further, we show that the density of TRPV4 at the plasma membrane decreased within 20 min, as they translocate to the recycling endosomes and that the surface density is dependent on the release of calcium from the intracellular stores and is controlled via a PI3K, PKC, and RhoA signaling pathway.
| S-EPMC6351496 | biostudies-literature
Project description:Endothelial cell dysfunction, characterized by a diminished response to endothelial cell-dependent vasodilators, is a hallmark of hypertension. TRPV4 channels play a major role in endothelial-dependent vasodilation, a function mediated by local Ca(2+) influx through clusters of functionally coupled TRPV4 channels rather than by a global increase in endothelial cell Ca(2+). We showed that stimulation of muscarinic acetylcholine receptors on endothelial cells of mouse arteries exclusively activated TRPV4 channels that were localized at myoendothelial projections (MEPs), specialized regions of endothelial cells that contact smooth muscle cells. Muscarinic receptor-mediated activation of TRPV4 depended on protein kinase C (PKC) and the PKC-anchoring protein AKAP150, which was concentrated at MEPs. Cooperative opening of clustered TRPV4 channels specifically amplified Ca(2+) influx at MEPs. Cooperativity of TRPV4 channels at non-MEP sites was much lower, and cooperativity at MEPs was greatly reduced by chelation of intracellular Ca(2+) or AKAP150 knockout, suggesting that Ca(2+) entering through adjacent channels underlies the AKAP150-dependent potentiation of TRPV4 activity. In a mouse model of angiotensin II-induced hypertension, MEP localization of AKAP150 was disrupted, muscarinic receptor stimulation did not activate TRPV4 channels, cooperativity among TRPV4 channels at MEPs was weaker, and vasodilation in response to muscarinic receptor stimulation was reduced. Thus, endothelial-dependent dilation of resistance arteries is enabled by MEP-localized AKAP150, which ensures the proximity of PKC to TRPV4 channels and the coupled channel gating necessary for efficient communication from endothelial to smooth muscle cells in arteries. Disruption of this molecular assembly may contribute to altered blood flow in hypertension.
| S-EPMC4403000 | biostudies-literature
Project description:The CD38-ADP-ribosylcyclase-mediated Ca(2+) signaling pathway importantly contributes to the vasomotor response in different arteries. Although there is evidence indicating that the activation of CD38-ADP-ribosylcyclase is associated with CD38 internalization, the molecular mechanism mediating CD38 internalization and consequent activation in response to a variety of physiological and pathological stimuli remains poorly understood. Recent studies have shown that CD38 may sense redox signals and is thereby activated to produce cellular response and that the NADPH oxidase isoform, NOX1, is a major resource to produce superoxide (O2·-)) in coronary arterial myocytes (CAMs) in response to muscarinic receptor agonist, which uses CD38-ADP-ribosylcyclase signaling pathway to exert its action in these CAMs. These findings led us hypothesize that NOX1-derived O2·- serves in an autocrine fashion to enhance CD38 internalization, leading to redox activation of CD38-ADP-ribosylcyclase activity in mouse CAMs. To test this hypothesis, confocal microscopy, flow cytometry and a membrane protein biotinylation assay were used in the present study. We first demonstrated that CD38 internalization induced by endothelin-1 (ET-1) was inhibited by silencing of NOX1 gene, but not NOX4 gene. Correspondingly, NOX1 gene silencing abolished ET-1-induced O2·- production and increased CD38-ADP-ribosylcyclase activity in CAMs, while activation of NOX1 by overexpression of Rac1 or Vav2 or administration of exogenous O2·- significantly increased CD38 internalization in CAMs. Lastly, ET-1 was found to markedly increase membrane raft clustering as shown by increased colocalization of cholera toxin-B with CD38 and NOX1. Taken together, these results provide direct evidence that Rac1-NOX1-dependent O2·- production mediates CD38 internalization in CAMs, which may represent an important mechanism linking receptor activation with CD38 activity in these cells.
| S-EPMC3737089 | biostudies-literature
Project description:Integrins are ubiquitous transmembrane mechanoreceptors that elicit changes in intracellular biochemistry in response to mechanical force application, but these alterations generally proceed over seconds to minutes. Stress-sensitive ion channels represent another class of mechanoreceptors that are activated much more rapidly (within msec), and recent findings suggest that calcium influx through Transient Receptor Potential Vanilloid-4 (TRPV4) channels expressed in the plasma membrane of bovine capillary endothelial cells is required for mechanical strain-induced changes in focal adhesion assembly, cell orientation and directional migration. However, whether mechanically stretching a cell's extracellular matrix (ECM) adhesions might directly activate cell surface ion channels remains unknown. Here we show that forces applied to beta1 integrins result in ultra-rapid (within 4 msec) activation of calcium influx through TRPV4 channels. The TRPV4 channels were specifically activated by mechanical strain in the cytoskeletal backbone of the focal adhesion, and not by deformation of the lipid bilayer or submembranous cortical cytoskeleton alone. This early-immediate calcium signaling response required the distal region of the beta1 integrin cytoplasmic tail that contains a binding site for the integrin-associated transmembrane CD98 protein, and external force application to CD98 within focal adhesions activated the same ultra-rapid calcium signaling response. Local direct strain-dependent activation of TRPV4 channels mediated by force transfer from integrins and CD98 may therefore enable compartmentalization of calcium signaling within focal adhesions that is critical for mechanical control of many cell behaviors that underlie cell and tissue development.
| S-EPMC3147167 | biostudies-literature
Project description:TREK channels are unique among two-pore-domain K(+) channels. They are activated by polyunsaturated fatty acids (PUFAs) including arachidonic acid (AA), phospholipids, mechanical stretch and intracellular acidification. They are inhibited by neurotransmitters and hormones. TREK-1 knockout mice have impaired PUFA-mediated neuroprotection to ischemia, reduced sensitivity to volatile anesthetics and altered perception of pain. Here, we show that the A-kinase-anchoring protein AKAP150 is a constituent of native TREK-1 channels. Its binding to a key regulatory domain of TREK-1 transforms low-activity outwardly rectifying currents into robust leak conductances insensitive to AA, stretch and acidification. Inhibition of the TREK-1/AKAP150 complex by Gs-coupled receptors such as serotonin 5HT4sR and noradrenaline beta2AR is as extensive as for TREK-1 alone, but is faster. Inhibition of TREK-1/AKAP150 by Gq-coupled receptors such as serotonin 5HT2bR and glutamate mGluR5 is much reduced when compared to TREK-1 alone. The association of AKAP150 with TREK channels integrates them into a postsynaptic scaffold where both G-protein-coupled membrane receptors (as demonstrated here for beta2AR) and TREK-1 dock simultaneously.
| S-EPMC1698884 | biostudies-literature
Project description:Microglia maintain central nervous system homeostasis by monitoring changes in their environment (resting state) and by taking protective actions to equilibrate such changes (activated state). These surveillance and protective roles both require constant movement of microglia. Interestingly, induced hypothermia can reduce microglia migration caused by ischemia, suggesting that microglia movement can be modulated by temperature. Although several ion channels and transporters are known to support microglia movement, the precise molecular mechanism that regulates temperature-dependent movement of microglia remains unclear. Some members of the transient receptor potential (TRP) channel superfamily exhibit thermosensitivity and thus are strong candidates for mediation of this phenomenon. Here, we demonstrate that mouse microglia exhibit temperature-dependent movement in vitro and in vivo that is mediated by TRPV4 channels within the physiological range of body temperature. Our findings may provide a basis for future research into the potential clinical application of temperature regulation to preserve cell function via manipulation of ion channel activity.
| S-EPMC8092382 | biostudies-literature
Project description:The physiological and neurological correlates of plummeting brain osmolality during edema, traumatic CNS injury, and severe ischemia are compounded by neuroinflammation. Using multiple approaches, we investigated how retinal microglia respond to challenges mediated by increases in strain, osmotic gradients, and agonists of the stretch-activated cation channel TRPV4. Dissociated and intact microglia were TRPV4-immunoreactive and responded to the selective agonist GSK1016790A and substrate stretch with altered motility and elevations in intracellular calcium ([Ca2+ ]i ). Agonist- and hypotonicity-induced swelling was associated with a nonselective outwardly rectifying cation current, increased [Ca2+ ]i , and retraction of higher-order processes. The antagonist HC067047 reduced the extent of hypotonicity-induced microglial swelling and inhibited the suppressive effects of GSK1016790A and hypotonicity on microglial branching. Microglial TRPV4 signaling required intermediary activation of phospholipase A2 (PLA2), cytochrome P450, and epoxyeicosatrienoic acid production (EETs). The expression pattern of vanilloid thermoTrp genes in retinal microglia was markedly different from retinal neurons, astrocytes, and cortical microglia. These results suggest that TRPV4 represents a primary retinal microglial sensor of osmochallenges under physiological and pathological conditions. Its activation, associated with PLA2, modulates calcium signaling and cell architecture. TRPV4 inhibition might be a useful strategy to suppress microglial overactivation in the swollen and edematous CNS.
| S-EPMC8989051 | biostudies-literature
Project description:TRPV4 channels, which respond to mechanical activation by permeating Ca2+ into the cell, may play a pivotal role in cardiac remodeling during cardiac overload. Our study aimed to investigate TRPV4 involvement in pathological and physiological remodeling through Ca2+-dependent signaling. TRPV4 expression was assessed in heart failure (HF) models, induced by isoproterenol infusion or transverse aortic constriction, and in exercise-induced adaptive remodeling models. The impact of genetic TRPV4 inhibition on HF was studied by echocardiography, histology, gene and protein analysis, arrhythmia inducibility, Ca2+ dynamics, calcineurin (CN) activity, and NFAT nuclear translocation. TRPV4 expression exclusively increased in HF models, strongly correlating with fibrosis. Isoproterenol-administered transgenic TRPV4-/- mice did not exhibit HF features. Cardiac fibroblasts (CFb) from TRPV4+/+ animals, compared to TRPV4-/-, displayed significant TRPV4 overexpression, elevated Ca2+ influx, and enhanced CN/NFATc3 pathway activation. TRPC6 expression paralleled that of TRPV4 in all models, with no increase in TRPV4-/- mice. In cultured CFb, the activation of TRPV4 by GSK1016790A increased TRPC6 expression, which led to enhanced CN/NFATc3 activation through synergistic action of both channels. In conclusion, TRPV4 channels contribute to pathological remodeling by promoting fibrosis and inducing TRPC6 upregulation through the activation of Ca2+-dependent CN/NFATc3 signaling. These results pose TRPV4 as a primary mediator of the pathological response.
| S-EPMC10855372 | biostudies-literature