Protease-Activated Receptor 1, 2 but Not 4 Sensitizes Transient Receptor Potential Vanilloid 4 in Human Intestinal Epithelial Cells

2011 ◽  
Vol 140 (5) ◽  
pp. S-840
Author(s):  
Emilie D'Aldebert ◽  
Nicolas Cenac ◽  
Charlyne Casteras ◽  
Nathalie Vergnolle
Keyword(s):  
Epithelial Cells ◽  
Transient Receptor Potential ◽  
Intestinal Epithelial Cells ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Intestinal Epithelial ◽  
Human Intestinal Epithelial Cells ◽  
Protease Activated Receptor 1 ◽  
Transient Receptor

TRPC1 functions as a store-operated Ca2+ channel in intestinal epithelial cells and regulates early mucosal restitution after wounding

2006 ◽  
Vol 290 (4) ◽  
pp. G782-G792 ◽  
Author(s):  
Jaladanki N. Rao ◽  
Oleksandr Platoshyn ◽  
Vera A. Golovina ◽  
Lan Liu ◽  
Tongtong Zou ◽  
...  
Keyword(s):  
Cell Migration ◽  
Epithelial Cells ◽  
Transient Receptor Potential ◽  
Intestinal Epithelial Cells ◽  
Critical Role ◽  
Receptor Potential ◽  
Mucosal Injury ◽  
Intestinal Epithelial ◽  
Epithelial Restitution ◽  
Transient Receptor

An increase in cytosolic free Ca2+ concentration ([Ca2+]cyt) results from Ca2+ release from intracellular stores and extracellular Ca2+ influx through Ca2+-permeable ion channels and is crucial for initiating intestinal epithelial restitution to reseal superficial wounds after mucosal injury. Capacitative Ca2+ entry (CCE) induced by Ca2+ store depletion represents a major Ca2+ influx mechanism, but the exact molecular components constituting this process remain elusive. This study determined whether canonical transient receptor potential (TRPC)1 served as a candidate protein for Ca2+-permeable channels mediating CCE in intestinal epithelial cells and played an important role in early epithelial restitution. Normal intestinal epithelial cells (the IEC-6 cell line) expressed TRPC1 and TPRC5 and displayed typical records of whole cell store-operated Ca2+ currents and CCE generated by Ca2+ influx after depletion of intracellular stores. Induced TRPC1 expression by stable transfection with the TRPC1 gene increased CCE and enhanced cell migration during restitution. Differentiated IEC-Cdx2L1 cells induced by forced expression of the Cdx2 gene highly expressed endogenous TRPC1 and TRPC5 and exhibited increased CCE and cell migration. Inhibition of TRPC1 expression by small interfering RNA specially targeting TRPC1 not only reduced CCE but also inhibited cell migration after wounding. These findings strongly suggest that TRPC1 functions as store-operated Ca2+ channels and plays a critical role in intestinal epithelial restitution by regulating CCE and intracellular [Ca2+]cyt.

Protease-activated receptor-1 stimulates Ca2+-dependent Cl−secretion in human intestinal epithelial cells

2001 ◽  
Vol 281 (2) ◽  
pp. G323-G332 ◽  
Author(s):  
M. C. Buresi ◽  
E. Schleihauf ◽  
N. Vergnolle ◽  
A. Buret ◽  
J. L. Wallace ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Short Circuit ◽  
Intestinal Lumen ◽  
Epithelial Cell Line ◽  
Intracellular Camp ◽  
Intestinal Epithelial ◽  
Rt Pcr ◽  
Human Intestinal Epithelial Cells ◽  
Protease Activated Receptor 1

The thrombin receptor, protease-activated receptor-1 (PAR-1), has wide tissue distribution and is involved in many physiological functions. Because thrombin is in the intestinal lumen and mucosa during inflammation, we sought to determine PAR-1 expression and function in human intestinal epithelial cells. RT-PCR showed PAR-1 mRNA expression in SCBN cells, a nontransformed duodenal epithelial cell line. Confluent SCBN monolayers mounted in Ussing chambers responded to PAR-1 activation with a Cl−-dependent increase in short-circuit current. The secretory effect was blocked by BaCl2and the Ca2+-ATPase inhibitor thapsigargin, but not by the L-type Ca2+channel blocker verapamil or DIDS, the nonselective inhibitor of Ca2+-dependent Cl−transport. Responses to thrombin and PAR-1-activating peptides exhibited auto- and crossdesensitization. Fura 2-loaded SCBN cells had increased fluorescence after PAR-1 activation, indicating increased intracellular Ca2+. RT-PCR showed that SCBN cells expressed mRNA for the cystic fibrosis transmembrane conductance regulator (CFTR) and hypotonicity-activated Cl−channel-2 but not for the Ca2+-dependent Cl−channel-1. PAR-1 activation failed to increase intracellular cAMP, suggesting that the CFTR channel is not involved in the Cl−secretory response. Our data demonstrate that PAR-1 is expressed on human intestinal epithelial cells and regulates a novel Ca2+-dependent Cl−secretory pathway. This may be of clinical significance in inflammatory intestinal diseases with elevated thrombin levels.

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 Induced TRPC1 expression sensitizes intestinal epithelial cells to apoptosis by inhibiting NF-κB activation through Ca2+ influx

2006 ◽  
Vol 397 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Bernard S. Marasa ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
Kaspar M. Keledjian ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transient Receptor Potential ◽  
Intestinal Epithelial Cells ◽  
Critical Role ◽  
Ectopic Expression ◽  
Receptor Potential ◽  
Nuclear Factor Κb ◽  
Intestinal Epithelial ◽  
Store Depletion ◽  
Increased Susceptibility

Apoptosis occurs within crypts and at the intestinal luminal surface and plays a critical role in mucosal homoeostasis. NF-κB (nuclear factor-κB) is the central regulator of the transcription of genes involved in apoptosis, and its activity is highly regulated in the intestinal mucosa. We have recently demonstrated that TRPC1 (transient receptor potential canonical-1) is expressed in IECs (intestinal epithelial cells) and functions as a Ca2+ permeable channel activated by Ca2+ store depletion. The present study tests the hypothesis that TRPC1 channels are implicated in the regulation of apoptosis by inhibiting NF-κB through the induction of TRPC1-mediated Ca2+ influx in the IEC-6 line. The expression of TRPC1 induced by stable transfection of IEC-6 cells with the wild-type TRPC1 gene (IEC-TRPC1 cells) increased Ca2+ influx after Ca2+ store depletion and repressed NF-κB transactivation, which was associated with an increase in susceptibility to apoptosis induced by exposure to TNFα (tumour necrosis factor-α) plus CHX (cycloheximide) (TNF-α/CHX), or STS (staurosporine). By contrast, the induction of endogenous NF-κB activity, by the depletion of cellular polyamines, promoted resistance to apoptosis, which was prevented by the ectopic expression of the IκBα super-repressor. Furthermore, inhibition of TRPC1 expression by transfection with siRNA (small interfering RNA) targeting TRPC1 (siTRPC1) decreased Ca2+ influx, increased NF-κB transactivation, and prevented the increased susceptibility of IEC-TRPC1 cells to apoptosis. Decreasing Ca2+ influx by exposure to a Ca2+-free medium also induced NF-κB activity and blocked the increased susceptibility to apoptosis of stable IEC-TRPC1 cells. These results indicate that induced TRPC1 expression sensitizes IECs to apoptosis by inhibiting NF-κB activity as a result of the stimulation of Ca2+ influx.

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