Dataset Information

Molecular mechanisms of caffeine-mediated intestinal epithelial ion transports.

ABSTRACT: BACKGROUND AND PURPOSE:As little is known about the effect of caffeine, one of the most widely consumed substances worldwide, on intestinal function, we aimed to study its action on intestinal anion secretion and the underlying molecular mechanisms. EXPERIMENTAL APPROACH:Anion secretion and channel expression were examined in mouse duodenal epithelium by Ussing chambers and immunocytochemistry. Ca2+ imaging was also performed in intestinal epithelial cells (IECs). KEY RESULTS:Caffeine (10 mM) markedly increased mouse duodenal short-circuit current (Isc ), which was attenuated by a removal of either Cl- or HCO3 - , Ca2+ -free serosal solutions and selective blockers of store-operated Ca2+ channels (SOC/Ca2+ release-activated Ca2+ channels), and knockdown of Orai1 channels on the serosal side of duodenal tissues. Caffeine induced SOC entry in IEC, which was inhibited by ruthenium red and selective blockers of SOC. Caffeine-stimulated duodenal Isc was inhibited by the endoplasmic reticulum Ca2+ chelator (N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine), selective blockers (ruthenium red and dantrolene) of ryanodine receptors (RyR), and of Ca2+ -activated Cl- channels (niflumic acid and T16A). There was synergism between cAMP and Ca2+ signalling, in which cAMP/PKA promoted caffeine/Ca2+ -mediated anion secretion. Expression of STIM1 and Orai1 was detected in mouse duodenal mucosa and human IECs. The Orai1 proteins were primarily co-located with the basolateral marker Na+ , K+ -ATPase. CONCLUSIONS AND IMPLICATIONS:Caffeine stimulated intestinal anion secretion mainly through the RyR/Orai1/Ca2+ signalling pathway. There is synergism between cAMP/PKA and caffeine/Ca2+ -mediated anion secretion. Our findings suggest that a caffeine-mediated RyR/Orai1/Ca2+ pathway could provide novel potential drug targets to control intestinal anion secretion.

SUBMITTER: Zhang F

PROVIDER: S-EPMC6514291 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Molecular mechanisms of caffeine-mediated intestinal epithelial ion transports.

Zhang Fenglian F Wan Hanxing H Yang Xin X He Jialin J Lu Cheng C Yang Shiming S Tuo Biguang B Dong Hui H

British journal of pharmacology 20190411 11

<h4>Background and purpose</h4>As little is known about the effect of caffeine, one of the most widely consumed substances worldwide, on intestinal function, we aimed to study its action on intestinal anion secretion and the underlying molecular mechanisms.<h4>Experimental approach</h4>Anion secretion and channel expression were examined in mouse duodenal epithelium by Ussing chambers and immunocytochemistry. Ca<sup>2+</sup> imaging was also performed in intestinal epithelial cells (IECs).<h4>Ke ...[more]

PMID: 30808064

Similar Datasets

Project description:Smoke inhalation injury is the leading cause of death in firefighters and victims. Inhaled hot air and toxic smoke are the predominant hazards to the respiratory epithelium. We aimed to analyze the effects of thermal stress and smoke aldehyde on the permeability of the airway epithelial barrier. Transepithelial resistance (RTE) and short-circuit current (ISC) of mouse tracheal epithelial monolayers were digitized by an Ussing chamber setup. Zonula occludens-1 tight junctions were visualized under confocal microscopy. A cell viability test and fluorescein isothiocyanate-dextran assay were performed. Thermal stress (40 °C) decreased RTE in a two-phase manner. Meanwhile, thermal stress increased ISC followed by its decline. Na+ depletion, amiloride (an inhibitor for epithelial Na+ channels [ENaCs]), ouabain (a blocker for Na+/K+-ATPase), and CFTRinh-172 (a blocker of cystic fibrosis transmembrane regulator [CFTR]) altered the responses of RTE and ISC to thermal stress. Steady-state 40 °C increased activity of ENaCs, Na+/K+-ATPase, and CFTR. Acrolein, one of the main oxidative unsaturated aldehydes in fire smoke, eliminated RTE and ISC. Na+ depletion, amiloride, ouabain, and CFTRinh-172 suppressed acrolein-sensitive ISC, but showed activating effects on acrolein-sensitive RTE. Thermal stress or acrolein disrupted zonula occludens-1 tight junctions, increased fluorescein isothiocyanate-dextran permeability but did not cause cell death or detachment. The synergistic effects of thermal stress and acrolein exacerbated the damage to monolayers. In conclusion, the paracellular pathway mediated by the tight junctions and the transcellular pathway mediated by active and passive ion transport pathways contribute to impairment of the airway epithelial barrier caused by thermal stress and acrolein. Graphical abstract Thermal stress and acrolein are two essential determinants for smoke inhalation injury, impairing airway epithelial barrier. Transcellular ion transport pathways via the ENaC, CFTR, and Na/K-ATPase are interrupted by both thermal stress and acrolein, one of the most potent smoke toxins. Heat and acrolein damage the integrity of the airway epithelium through suppressing and relocating the tight junctions.

Dataset Information

Molecular mechanisms of caffeine-mediated intestinal epithelial ion transports.

Publications

Molecular mechanisms of caffeine-mediated intestinal epithelial ion transports.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets