Functional expression of transient receptor potential vanilloid 3 (TRPV3) in corneal epithelial cells: Involvement in thermosensation and wound healing

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.

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Sa1725 H. pylori Infection Directly Induces Methylation Silencing of a Gastric Epithelial Mechano-Sensor, Transient Receptor Potential Vanilloid 4 in Gastric Epithelial Cells

Gastroenterology ◽

10.1016/s0016-5085(16)31254-9 ◽

2016 ◽

Vol 150 (4) ◽

pp. S358

Author(s):

Hiroshi Mihara ◽

Jibran Sualeh Muhammad ◽

Sohachi Nanjo ◽

Takayuki Ando ◽

Toshiro Sugiyama

Keyword(s):

Epithelial Cells ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Transient Receptor Potential Vanilloid ◽

Gastric Epithelial Cells ◽

Transient Receptor ◽

H Pylori

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

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00162.2015 ◽

2015 ◽

Vol 309 (8) ◽

pp. G695-G702 ◽

Cited By ~ 14

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.

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Functional Expression of an Osmosensitive Cation Channel, Transient Receptor Potential Vanilloid 4, in Rat Vestibular Ganglia

Audiology and Neurotology ◽

10.1159/000449238 ◽

2016 ◽

Vol 21 (4) ◽

pp. 268-274 ◽

Cited By ~ 3

Author(s):

Takefumi Kamakura ◽

Makoto Kondo ◽

Yoshihisa Koyama ◽

Yukiko Hanada ◽

Yusuke Ishida ◽

...

Keyword(s):

Transient Receptor Potential ◽

Receptor Potential ◽

Functional Expression ◽

Ruthenium Red ◽

Cation Channel ◽

Trigeminal Ganglia ◽

Transient Receptor Potential Vanilloid ◽

Trpv Channels ◽

Polymerase Chain ◽

Transient Receptor

Transient receptor potential vanilloid (TRPV) 4 is a nonselective cation channel expressed in sensory neurons such as those in the dorsal root and trigeminal ganglia, kidney, and inner ear. TRPV4 is activated by mechanical stress, heat, low osmotic pressure, low pH, and phorbol derivatives such as 4α-phorbol 12,13-didecanoate (4α-PDD). We investigated the expression of TRPV4 in rat vestibular ganglion (VG) neurons. The TRPV4 gene was successfully amplified from VG neuron mRNA using reverse-transcription polymerase chain reaction. Furthermore, immunoblotting showed positive expression of TRPV4 protein in VG neurons. Immunohistochemistry indicated that TRPV4 was localized predominantly on the plasma membrane of VG neurons. Calcium (Ca2+) imaging of VG neurons showed that 4α-PDD and/or hypotonic stimuli caused an increase in intracellular Ca2+ concentration ([Ca2+]i) that was almost completely inhibited by ruthenium red, a selective antagonist of TRPV channels. Interestingly, a [Ca2+]i increase was evoked by both hypotonic stimuli and 4α-PDD in approximately 38% of VG neurons. These data indicate that TRPV4 is functionally expressed in VG neurons as an ion channel and that TRPV4 likely participates in VG neurons for vestibular neurotransmission as an osmoreceptor and/or mechanoreceptor.

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

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00013.2021 ◽

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.

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