PAR-2 activation enhances weak acid-induced ATP release through TRPV1 and ASIC sensitization in human esophageal epithelial cells

2015 ◽  
Vol 309 (8) ◽  
pp. G695-G702 ◽  
Author(s):  
Liping Wu ◽  
Tadayuki Oshima ◽  
Jing Shan ◽  
Hiroo Sei ◽  
Toshihiko Tomita ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transient Receptor Potential ◽  
Atp Release ◽  
Receptor Potential ◽  
Weak Acid ◽  
Transient Receptor Potential Vanilloid ◽  
Esophageal Epithelial Cells ◽  
Transient Receptor ◽  
Esophageal Hypersensitivity ◽  
Interfering Rna

Esophageal visceral hypersensitivity has been proposed to be the pathogenesis of heartburn sensation in nonerosive reflux disease. Protease-activated receptor-2 (PAR-2) is expressed in human esophageal epithelial cells and is believed to play a role in inflammation and sensation. PAR-2 activation may modulate these responses through adenosine triphosphate (ATP) release, which is involved in transduction of sensation and pain. The transient receptor potential vanilloid receptor 1 (TRPV1) and acid-sensing ion channels (ASICs) are both acid-sensitive nociceptors. However, the interaction among these molecules and the mechanisms of heartburn sensation are still not clear. We therefore examined whether ATP release in human esophageal epithelial cells in response to acid is modulated by TRPV1 and ASICs and whether PAR-2 activation influences the sensitivity of TRPV1 and ASICs. Weak acid (pH 5) stimulated the release of ATP from primary human esophageal epithelial cells (HEECs). This effect was significantly reduced after pretreatment with 5-iodoresiniferatoxin (IRTX), a TRPV1-specific antagonist, or with amiloride, a nonselective ASIC blocker. TRPV1 and ASIC3 small interfering RNA (siRNA) transfection also decreased weak acid-induced ATP release. Pretreatment of HEECs with trypsin, tryptase, or a PAR-2 agonist enhanced weak acid-induced ATP release. Trypsin treatment led to the phosphorylation of TRPV1. Acid-induced ATP release enhancement by trypsin was partially blocked by IRTX, amiloride, or a PAR-2 antagonist. Conversely, acid-induced ATP release was augmented by PAR-2 activation through TRPV1 and ASICs. These findings suggested that the pathophysiology of heartburn sensation or esophageal hypersensitivity may be associated with the activation of PAR-2, TRPV1, and ASICs.

scholarly journals Mechanosensor transient receptor potential vanilloid member 4 (TRPV4) regulates mouse cholangiocyte secretion and bile formation

2020 ◽  
Vol 318 (2) ◽  
pp. G277-G287
Author(s):  
Qin Li ◽  
Charles Kresge ◽  
Kristy Boggs ◽  
Julie Scott ◽  
Andrew Feranchak
Keyword(s):  
Fluid Flow ◽  
Bile Flow ◽  
Transient Receptor Potential ◽  
Atp Release ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Bile Formation ◽  
Transport Pathways ◽  
Transient Receptor

Mechanosensitive signaling has emerged as a mechanism for the regulation of cholangiocyte transport and bile formation. The mechanical effect of fluid-flow, or shear, at the apical membrane of cholangiocytes regulates secretion through a process involving increases in [Ca2+]i and activation of Ca2+-activated Cl− channels. However, the initiating steps translating shear force to increases in intracellular calcium concentration ([Ca2+]i) are unknown. Transient receptor potential vanilloid member 4 (TRPV4), a nonselective cation channel present in the apical membrane of cholangiocytes, has been proposed as a potential mechanosensor. The aim of the present studies was to determine the potential role of TRPV4 in initiating mechanosensitive signaling in response to fluid-flow in cholangiocytes. TRPV4 expression was confirmed in both small and large mouse cholangiocytes. Exposure of cells to either fluid flow or specific TRPV4 pharmacological agonists rapidly increased both [Ca2+]i and membrane cation currents. Both flow- and agonist-stimulated currents displayed identical biophysical properties and were inhibited in the presence of TRPV4 antagonists or in cells after transfection with TRPV4 small interfering RNA. Transfection of mouse cholangiocytes with a TRPV4-enhanced green fluorescent protein construct increased the expression of TRPV4 and the magnitude of flow-stimulated currents. A specific TRPV4 agonist significantly increased the biliary concentration of ATP and bile flow in live mice when administered intravenously and increased ATP release from cholangiocyte monolayers when applied exogenously. The findings are consistent with a model in which activation of cholangiocyte TRPV4 translates shear force into an acute rise in membrane cation permeability, [Ca2+]i, ATP release, and bile flow. Understanding the role of mechanosensitive transport pathways may provide novel insights to modulate bile flow for the treatment of cholestatic liver disorders. NEW & NOTEWORTHY These studies functionally characterize TRPV4 as a mechanosensitive channel in mouse cholangiocytes. By mediating a rapid rise in intracellular Ca2+, necessary for Ca2+-dependent secretion, TRPV4 represents a mechanosensor responsible for translating fluid flow into intracellular signaling and biliary secretion. Furthermore, intravenous infusion of a specific TRPV4 agonist increases bile flow in live mice. Understanding the role of TRPV4 in mechanosensitive transport pathways may provide novel insights to modulate bile flow during cholestasis.

scholarly journals TRPV4 blockade reduces voiding frequency, ATP release, and pelvic sensitivity in mice with chronic urothelial overexpression of NGF

2019 ◽  
Vol 317 (6) ◽  
pp. F1695-F1706 ◽  
Author(s):  
Beatrice M. Girard ◽  
Susan E. Campbell ◽  
Megan Perkins ◽  
Harrison Hsiang ◽  
Katharine Tooke ◽  
...  
Keyword(s):  
Urinary Bladder ◽  
Transient Receptor Potential ◽  
Atp Release ◽  
Brefeldin A ◽  
Receptor Potential ◽  
Fold Increase ◽  
Void Volume ◽  
Bladder Function ◽  
Transient Receptor Potential Vanilloid ◽  
Transient Receptor

Transient receptor potential vanilloid family member 4 (TRPV4) transcript and protein expression increased in the urinary bladder and lumbosacral dorsal root ganglia of transgenic mice with chronic urothelial overexpression of nerve growth factor (NGF-OE). We evaluated the functional role of TRPV4 in bladder function with open-outlet cystometry, void spot assays, and natural voiding (Urovoid) assays with the TRPV4 antagonist HC-067047 (1 μM) or vehicle in NGF-OE and littermate wild-type (WT) mice. Blockade of TRPV4 at the level of the urinary bladder significantly ( P ≤ 0.01) increased the intercontraction interval (2.2-fold) and void volume (2.6-fold) and decreased nonvoiding contractions (3.0-fold) in NGF-OE mice, with lesser effects (1.3-fold increase in the intercontraction interval and 1.3-fold increase in the void volume) in WT mice. Similar effects of TRPV4 blockade on bladder function in NGF-OE mice were demonstrated with natural voiding assays. Intravesical administration of HC-067047 (1 µM) significantly ( P ≤ 0.01) reduced pelvic sensitivity in NGF-OE mice but was without effect in littermate WT mice. Blockade of urinary bladder TRPV4 or intravesical infusion of brefeldin A significantly ( P ≤ 0.01) reduced (2-fold) luminal ATP release from the urinary bladder in NGF-OE and littermate WT mice. The results of the present study suggest that TRPV4 contributes to luminal ATP release from the urinary bladder and increased voiding frequency and pelvic sensitivity in NGF-OE mice.

Role of transient receptor potential vanilloid 4 activation in indomethacin-induced intestinal damage

2014 ◽  
Vol 307 (1) ◽  
pp. G33-G40 ◽  
Author(s):  
Hidemoto Yamawaki ◽  
Hiroshi Mihara ◽  
Nobuhiro Suzuki ◽  
Hirofumi Nishizono ◽  
Kunitoshi Uchida ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Intestinal Cell ◽  
Transient Receptor Potential Vanilloid ◽  
Intestinal Damage ◽  
Epoxyeicosatrienoic Acid ◽  
Intestinal Cell Line ◽  
Transient Receptor ◽  
Interfering Rna

Gastrointestinal ulcers and bleeding are serious complications of nonsteroidal anti-inflammatory drug (NSAID) use. Although administration of antibiotics and Toll-like receptor 4 knockdown mitigate NSAID-induced enteropathy, the molecular mechanism of these effects is poorly understood. Intestinal hyperpermeability is speculated to trigger the initial damage due to NSAID use. Transient receptor potential vanilloid 4 (TRPV4) is a nonselective cation channel expressed throughout the gastrointestinal tract epithelium that is activated by temperature, extension, and chemicals such as 5,6-epoxyeicosatrienoic acid (5,6-EET). The aim of this study was to investigate the possible role of TRPV4 in NSAID-induced intestinal damage. TRPV4 mRNA and protein expression was confirmed by RT-PCR and immunochemistry, respectively, in mouse and human tissues while TRPV4 channel activity of the intestinal cell line IEC-6 was assessed by Ca2+-imaging analysis. TRPV4 activators or the NSAID indomethacin significantly decreased transepithelial resistance (TER) in IEC-6 cells, and indomethacin-induced TER decreases were inhibited by specific TRPV4 inhibitors or small-interfering RNA TRPV4 knockdown, as well as by the epoxygenase inhibitor N-(methylsulfonyl)-2-(2-propynyloxy)-benzenehexanamide, which decreased 5,6-EET levels. In TRPV4 knockout mice, indomethacin-induced intestinal damage was significantly reduced compared with WT mice. Taken together, these results show that TRPV4 activation in the intestinal epithelium caused epithelial hyperpermeability in response to NSAID-induced arachidonic acid metabolites and contributed to NSAID-induced intestinal damage. Thus, TRPV4 could be a promising new therapeutic target for the prevention of NSAID-induced intestinal damage.

Transient Receptor Potential Vanilloid 4 Dependent Calcium Influx and ATP Release in Mouse Esophageal Keratinocytes

2011 ◽  
Vol 140 (5) ◽  
pp. S-625
Author(s):  
Hiroshi Mihara ◽  
Ammar Boudaka ◽  
Toshiro Sugiyama ◽  
Yoshinori Moriyama ◽  
Makoto Tominaga
Keyword(s):  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Atp Release ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Transient Receptor

Heartburn Sensation in Non-Erosive Reflux Disease: Pattern of Superficial Sensory Nerves Expressing TRPV1 and Epithelial Cells Expressing ASIC3 Receptors

2021 ◽  
Author(s):  
Ahsen Ustaoglu ◽  
Akinari Sawada ◽  
Chung Lee ◽  
Wei-Yi Lei ◽  
Chien-Lin Chen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Reflux Disease ◽  
Transient Receptor Potential ◽  
Sensory Nerve ◽  
Receptor Potential ◽  
Sensory Nerves ◽  
Transient Receptor Potential Vanilloid ◽  
Esophageal Mucosa ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor

The underlying causes of heartburn, characteristic symptom of gastro-esophageal reflux disease(GERD), remain incompletely understood. Superficial afferent innervation of the esophageal mucosa in nonerosive reflux disease(NERD) may drive nociceptive reflux perception, but its acid-sensing role has not yet been established. Transient receptor potential vanilloid subfamily member-1(TRPV1), transient receptor potential Melastatin 8(TRPM8), and acid sensing ion channel 3(ASIC3) are regulators of sensory nerve activity and could be important reflux-sensing receptors within the esophageal mucosa. We characterised TRPV1, TRPM8, and ASIC3 expression in esophageal mucosa of GERD patients. We studied 10 NERD, 10 erosive reflux disease(ERD), 7 functional heartburn(FH), and 8 Barrett's esophagus(BE) patients. Biopsies obtained from the distal esophageal mucosa were co-stained with TRPV1, TRPM8, or ASIC3, and CGRP, CD45, or E-cadherin. RNA expression of TRPV1, TRPM8, and ASIC3 was assessed using qPCR. NERD patients had significantly increased expression of TRPV1 on superficial sensory nerves compared to ERD (p=0.028) or BE (p=0.017). Deep intrapapillary nerve endings did not express TRPV1 in all phenotypes studied. ASIC3 was exclusively expressed on epithelial cells most significantly in NERD and ERD patients (p=<0.0001). TRPM8 was expressed on submucosal CD45+ leukocytes. Superficial localisation of TRPV1-immunoreactive nerves in NERD, and increased ASIC3 co-expression on epithelial cells in NERD and ERD suggests a mechanism for heartburn sensation. Esophageal epithelial cells may play a sensory role in acid reflux perception and act interdependently with TRPV1-expressing mucosal nerves to augment hypersensitivity in NERD patients, raising the enticing possibility of topical antagonists for these ion channels as a therapeutic option.

scholarly journals Transient receptor potential vanilloid 4-dependent calcium influx and ATP release in mouse and rat gastric epithelia

2016 ◽  
Vol 22 (24) ◽  
pp. 5512 ◽  
Author(s):  
Hiroshi Mihara ◽  
Nobuhiro Suzuki ◽  
Ammar Abdullkader Boudaka ◽  
Jibran Sualeh Muhammad ◽  
Makoto Tominaga ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Atp Release ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Transient Receptor
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