scholarly journals A TRPV2–PKA Signaling Module for Transduction of Physical Stimuli in Mast Cells

2004 ◽  
Vol 200 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Alexander J. Stokes ◽  
Lori M.N. Shimoda ◽  
Murielle Koblan-Huberson ◽  
Chaker N. Adra ◽  
Helen Turner

Cutaneous mast cell responses to physical (thermal, mechanical, or osmotic) stimuli underlie the pathology of physical urticarias. In vitro experiments suggest that mast cells respond directly to these stimuli, implying that a signaling mechanism couples functional responses to physical inputs in mast cells. We asked whether transient receptor potential (vanilloid) (TRPV) cation channels were present and functionally coupled to signaling pathways in mast cells, since expression of this channel subfamily confers sensitivity to thermal, osmotic, and pressure inputs. Transcripts for a range of TRPVs were detected in mast cells, and we report the expression, surface localization, and oligomerization of TRPV2 protein subunits in these cells. We describe the functional coupling of TRPV2 protein to calcium fluxes and proinflammatory degranulation events in mast cells. In addition, we describe a novel protein kinase A (PKA)–dependent signaling module, containing PKA and a putative A kinase adapter protein, Acyl CoA binding domain protein (ACBD)3, that interacts with TRPV2 in mast cells. We propose that regulated phosphorylation by PKA may be a common pathway for TRPV modulation.

2017 ◽  
Vol 126 (2) ◽  
pp. 300-311 ◽  
Author(s):  
Laura Michalick ◽  
Lasti Erfinanda ◽  
Ulrike Weichelt ◽  
Markus van der Giet ◽  
Wolfgang Liedtke ◽  
...  

Abstract Background Mechanical ventilation can cause lung endothelial barrier failure and inflammation cumulating in ventilator-induced lung injury. Yet, underlying mechanotransduction mechanisms remain unclear. Here, the authors tested the hypothesis that activation of the mechanosensitive Ca2+ channel transient receptor potential vanilloid (TRPV4) by serum glucocorticoid–regulated kinase (SGK) 1 may drive the development of ventilator-induced lung injury. Methods Mice (total n = 54) were ventilated for 2 h with low (7 ml/kg) or high (20 ml/kg) tidal volumes and assessed for signs of ventilator-induced lung injury. Isolated-perfused lungs were inflated with continuous positive airway pressures of 5 or 15 cm H2O (n = 7 each), and endothelial calcium concentration was quantified by real-time imaging. Results Genetic deficiency or pharmacologic inhibition of TRPV4 or SGK1 protected mice from overventilation-induced vascular leakage (reduction in alveolar protein concentration from 0.84 ± 0.18 [mean ± SD] to 0.46 ± 0.16 mg/ml by TRPV4 antagonization), reduced lung inflammation (macrophage inflammatory protein 2 levels of 193 ± 163 in Trpv4−/−vs. 544 ± 358 pmol/ml in wild-type mice), and attenuated endothelial calcium responses to lung overdistension. Functional coupling of TRPV4 and SGK1 in lung endothelial mechanotransduction was confirmed by proximity ligation assay demonstrating enhanced TRPV4 phosphorylation at serine 824 at 18% as compared to 5% cyclic stretch, which was prevented by SGK1 inhibition. Conclusions Lung overventilation promotes endothelial calcium influx and barrier failure through a mechanism that involves activation of TRPV4, presumably due to phosphorylation at its serine 824 residue by SGK1. TRPV4 and SGK1 may present promising new targets for prevention or treatment of ventilator-induced lung injury.


2014 ◽  
Vol 306 (4) ◽  
pp. H574-H584 ◽  
Author(s):  
Jack Rubinstein ◽  
Valerie M. Lasko ◽  
Sheryl E. Koch ◽  
Vivek P. Singh ◽  
Vinicius Carreira ◽  
...  

Transient receptor potential cation channels have been implicated in the regulation of cardiovascular function, but only recently has our laboratory described the vanilloid-2 subtype (TRPV2) in the cardiomyocyte, though its exact mechanism of action has not yet been established. This study tests the hypothesis that TRPV2 plays an important role in regulating myocyte contractility under physiological conditions. Therefore, we measured cardiac and vascular function in wild-type and TRPV2−/− mice in vitro and in vivo and found that TRPV2 deletion resulted in a decrease in basal systolic and diastolic function without affecting loading conditions or vascular tone. TRPV2 stimulation with probenecid, a relatively selective TRPV2 agonist, caused an increase in both inotropy and lusitropy in wild-type mice that was blunted in TRPV2−/− mice. We examined the mechanism of TRPV2 inotropy/lusitropy in isolated myocytes and found that it modulates Ca2+ transients and sarcoplasmic reticulum Ca2+ loading. We show that the activity of this channel is necessary for normal cardiac function and that there is increased contractility in response to agonism of TRPV2 with probenecid.


2018 ◽  
Vol 315 (6) ◽  
pp. C793-C802 ◽  
Author(s):  
Mohammad Shahidullah ◽  
Amritlal Mandal ◽  
Nicholas A. Delamere

Lens ion homeostasis is crucial in maintaining water content and, in turn, refractive index and transparency of the multicellular syncytium-like structure. New information is emerging on the regulation of ion transport in the lens by mechanisms that rely on transient receptor potential vanilloid (TRPV) ion channels. We found recently that TRPV1 activation leads to Ca2+/PKC-dependent ERK1/2 signaling. Here, we show that the TRPV1 agonist capsaicin (100 nM) and hyperosmotic solution (350 vs. 300 mosM) each caused an increase of bumetanide-inhibitable Rb uptake by intact porcine lenses and Na-K-2Cl cotransporter 1 (NKCC1) phosphorylation in the lens epithelium. The TRPV1 antagonist A889425 (1 µM) abolished the increases of Rb uptake and NKCC1 phosphorylation in response to hyperosmotic solution. Exposing lenses to hyperosmotic solution in the presence of MEK/ERK inhibitor U0126 (10 µM) or the with-no-lysine kinase (WNK) inhibitor WNK463 (1 µM) also prevented NKCC1 phosphorylation and the Rb uptake responses to hyperosmotic solution. WNK463 did not prevent the increase in ERK1/2 phosphorylation that occurs in response to capsaicin or hyperosmotic solution, suggesting that ERK1/2 activation occurs before WNK activation in the sequence of signaling events. Taken together, the evidence indicates that activation of TRPV1 is a critical early step in a signaling mechanism that responds to a hyperosmotic stimulus, possibly lens shrinkage. By activating ERK1/2 and WNK, TRPV1 activation leads to NKCC1 phosphorylation and stimulation of NKCC1-mediated ion transport.


2021 ◽  
Author(s):  
Yang Zhang ◽  
Pengfei Liang ◽  
Ke Zoe Shan ◽  
Liping Feng ◽  
Yong Chen ◽  
...  

TMEM16F, a Ca2+-activated phospholipid scramblase (CaPLSase), is critical for placental trophoblast syncytialization, HIV infection, and SARS-CoV2-mediated syncytialization. How TMEM16F is activated during cell fusion is unclear. Here, we used trophoblasts as a model for cell fusion and demonstrated that Ca2+ influx through Ca2+ permeable transient receptor potential vanilloid channel TRPV4 is critical for TMEM16F activation and subsequent human trophoblast fusion. GSK1016790A, a TRPV4 specific agonist, robustly activates TMEM16F in trophoblasts. Patch-clamp electrophysiology demonstrated that TRPV4 and TMEM16F are functionally coupled within Ca2+ microdomains in human trophoblasts. Pharmacological inhibition or gene silencing of TRPV4 hindered TMEM16F activation and subsequent trophoblast syncytialization. Our study uncovers the functional expression of TRPV4 and a physiological activation mechanism of TMEM16F in human trophoblasts, thus providing us with novel strategies to regulate CaPLSase activity as a critical checkpoint of physiologically- and disease-relevant cell fusion events.


2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Qiongfeng Wu ◽  
Kai Lu ◽  
Zhaoyang Zhao ◽  
Binbin Wang ◽  
Huixia Liu ◽  
...  

Antioxidative stress provides a cardioprotective effect during myocardial ischemia/reperfusion (I/R). Previous research has demonstrated that the blockade of transient receptor potential vanilloid 4 (TRPV4) attenuates myocardial I/R injury. However, the underlying mechanism remains unclear. The current study is aimed at investigating the antioxidative activity of TRPV4 inhibition and elucidating the underlying mechanisms in vitro and ex vivo. We found that the inhibiting TRPV4 by the selective TRPV4 blocker HC-067047 or specific TRPV4-siRNA significantly reduces reactive oxygen species (ROS) and methane dicarboxylic aldehyde (MDA) levels in H9C2 cells exposed to hypoxia/reoxygenation (H/R). Meanwhile, the activity of antioxidative enzymes, particularly superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), is enhanced. Furthermore, after H/R, HC-067047 treatment increases the expression of P-Akt and the translocation of nuclear factor E2-related factor 2 (Nrf2) and related antioxidant response element (ARE) mainly including SOD, GSH-Px, and catalase (CAT). LY294002, an Akt inhibitor, suppresses HC-067047 and specific TRPV4-siRNA-induced Nrf2 expression and its nuclear accumulation. Nrf2 siRNA attenuates HC-067047 and specific TRPV4-siRNA-induced ARE expression. In addition, treatment with LY294002 or Nrf2 siRNA significantly attenuates the antioxidant and anti-injury effects of HC-067047 in vitro. Finally, in experiments on isolated rat hearts, we confirmed the antioxidative stress roles of TRPV4 inhibition during myocardial I/R and the application of exogenous H2O2. In conclusion, the inhibition of TRPV4 exerts cardioprotective effects through enhancing antioxidative enzyme activity and expressions via the Akt/Nrf2/ARE pathway.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Chang-Qing Yang ◽  
Yan-Yu Wei ◽  
Chan-Juan Zhong ◽  
Li-Ping Duan

Mast cells (MCs) deficient rats (Ws/Ws) were used to investigate the roles of MCs in visceral hyperalgesia. Ws/Ws and wild control (+/+) rats were exposed toT. spiralisor submitted to acute cold restraint stress (ACRS). Levels of proteinase-activated receptor 2 (PAR2) and nerve growth factor (NGF) were determined by immunoblots and RT-PCR analysis, and the putative signal pathways including phosphorylated extracellular-regulated kinase (pERK1/2) and transient receptor potential vanilloid receptor 1 (TRPV1) were further identified. Visceral hyperalgesia triggered by ACRS was observed only in+/+rats. The increased expression of PAR2 and NGF was observed only in+/+rats induced byT. spiralisand ACRS. The activation of pERK1/2 induced by ACRS occurred only in+/+rats. However, a significant increase of TRPV1 induced byT. spiralisand ACRS was observed only in+/+rats. The activation of PAR2 and NGF via both TRPV1 and pERK1/2 signal pathway is dependent on MCs in ACRS-induced visceral hyperalgesia rats.


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