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Molecular mechanisms of caffeine-mediated intestinal epithelial ion transports
- Source :
- Br J Pharmacol
- Publication Year :
- 2018
-
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. Ca(2+) imaging was also performed in intestinal epithelial cells (IECs). KEY RESULTS: Caffeine (10 mM) markedly increased mouse duodenal short‐circuit current (I (sc)), which was attenuated by a removal of either Cl(−) or HCO(3) (−), Ca(2+)‐free serosal solutions and selective blockers of store‐operated Ca(2+) channels (SOC/Ca(2+) release‐activated Ca(2+) 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 I (sc) was inhibited by the endoplasmic reticulum Ca(2+) chelator (N,N,N′,N′‐tetrakis(2‐pyridylmethyl)ethylenediamine), selective blockers (ruthenium red and dantrolene) of ryanodine receptors (RyR), and of Ca(2+)‐activated Cl(−) channels (niflumic acid and T16A). There was synergism between cAMP and Ca(2+) signalling, in which cAMP/PKA promoted caffeine/Ca(2+)‐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/Ca(2+) signalling pathway. There is synergism between cAMP/PKA and caffeine/Ca(2+)‐mediated anion secretion. Our findings suggest that a caffeine‐mediated RyR/Orai1/Ca(2+) pathway could provide novel potential drug targets to control intestinal anion secretion.
- Subjects :
- inorganic chemicals
0301 basic medicine
Male
Ruthenium red
ORAI1 Protein
Duodenum
Cell Line
03 medical and health sciences
chemistry.chemical_compound
0302 clinical medicine
Dogs
Chlorides
Caffeine
medicine
Cyclic AMP
Animals
Humans
Secretion
Calcium Signaling
Intestinal Mucosa
Pharmacology
Ryanodine receptor
Chemistry
ORAI1
Endoplasmic reticulum
Niflumic acid
STIM1
Ryanodine Receptor Calcium Release Channel
Molecular biology
Research Papers
Mice, Inbred C57BL
Bicarbonates
030104 developmental biology
Calcium
030217 neurology & neurosurgery
medicine.drug
Subjects
Details
- ISSN :
- 14765381
- Volume :
- 176
- Issue :
- 11
- Database :
- OpenAIRE
- Journal :
- British journal of pharmacology
- Accession number :
- edsair.doi.dedup.....b72d2ff85c523e718943d7773451a501