Effect of Sphingosine-1-Phosphate on Intracellular Free Ca2+ in Cat Esophageal Smooth Muscle Cells
Biomolecules & Therapeutics
;
: 546-552, 2018.
Artigo
em Inglês
| WPRIM
| ID: wpr-717999
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 G(i)-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 G(i) protein, via phospholipase C-mediated Ca²⁺ release from the InsP₃-sensitive Ca²⁺ pool in cat esophageal smooth muscle cells.
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Fosfolipases Tipo C
/
Fosfolipases
/
Retículo Sarcoplasmático
/
Nimodipina
/
Cálcio
/
Fura-2
/
Ácido Egtázico
/
Tapsigargina
/
Miócitos de Músculo Liso
/
Toxina Pertussis
Limite:
Animais
Idioma:
Inglês
Revista:
Biomolecules & Therapeutics
Ano de publicação:
2018
Tipo de documento:
Artigo
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