|
KMID : 0606920180260060546
|
|
Biomolecules & Therapeutics
2018 Volume.26 No. 6 p.546 ~ p.552
|
|
|
Effect of Sphingosine-1-Phosphate on Intracellular Free Ca2+ in Cat Esophageal Smooth Muscle Cells
|
|
Lee Dong-Kyu
Min Young-Sil
Yoo Seong-Su
Shim Hyun-Sub
Park Sun-Young
Sohn Uy-Dong
|
|
|
Abstract
|
|
|
|
A comprehensive collection of proteins senses local changes in intracellular Ca2+ concentrations ([Ca2+]i) and transduces these signals into responses to agonists. In the present study, we examined the effect of sphingosine-1-phosphate (S1P) on modulation of intracellular Ca2+ concentrations in cat esophageal smooth muscle cells. To measure [Ca2+]i levels in cat esophageal smooth muscle cells, we used a fluorescence microscopy with the Fura-2 loading method. S1P produced a concentration-dependent increase in [Ca2+]i in the cells. Pretreatment with EGTA, an extracellular Ca2+ chelator, decreased the S1P-induced increase in [Ca2+]i, and an L-type Ca2+-channel blocker, nimodipine, decreased the effect of S1P. This indicates that Ca2+ influx may be required for muscle contraction by S1P. When stimulated with thapsigargin, an intracellular calcium chelator, or 2-Aminoethoxydiphenyl borate (2-APB), an InsP3 receptor blocker, the S1P-evoked increase in [Ca2+]i was significantly decreased. Treatment with pertussis toxin (PTX), an inhibitor of Gi-protein, suppressed the increase in [Ca2+]i evoked by S1P. These results suggest that the S1P-induced increase in [Ca2+]i in cat esophageal smooth muscle cells occurs upon the activation of phospholipase C and subsequent release of Ca2+ from the InsP3-sensitive Ca2+ pool in the sarcoplasmic reticulum. These results suggest that S1P utilized extracellular Ca2+ via the L type Ca2+ channel, which was dependent on activation of the S1P4 receptor coupled to PTX-sensitive Gi protein, via phospholipase C-mediated Ca2+ release from the InsP3-sensitive Ca2+ pool in cat esophageal smooth muscle cells.
|
|
|
KEYWORD
|
|
|
Sphingosine-1-phosphate, Calcium, Fura-2, Esophageal cells, 2-Aminoethoxydiphenyl borate, Nimodipine
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|