Na+-Ca2+ exchanger modulates Ca2+ content in intracellular Ca2+ stores in rat osteoblasts
Experimental & Molecular Medicine
; : 458-468, 2007.
Article
Dans En
| WPRIM
| ID: wpr-174058
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ABSTRACT
Na+ -Ca2+ exchanger (NCX) transports Ca2+ coupled with Na+ across the plasma membrane in a bi-directional mode. Ca2+ flux via NCX mediates osteogenic processes, such as formation of extracellular matrix proteins and bone nodules. However, it is not clearly understood how the NCX regulates cellular Ca2+ movements in osteogenic processes. In this study, the role of NCX in modulating Ca2+ content of intracellular stores ([Ca2+](ER)) was investigated by measuring intracellular Ca2+ activity in isolated rat osteoblasts. Removal of extracellular Na+ elicited a transient increase of intracellular Ca2+ concentration ([Ca2+](i)). Pretreatment of antisense oligodeoxynucleotide (AS) against NCX depressed this transient Ca2+ rise and raised the basal level of [Ca2+](i). In AS-pretreated cells, the expression and activity of alkaline phosphatase (ALP), an osteogenic marker, were decreased. However, the cell viability was not affected by AS-pretreatment. Suppression of NCX activity by the AS-pretreatment decreased ATP-activated Ca2+ release from intracellular stores and significantly enhanced Ca2+ influx via store operated calcium influx (SOCI), compared to those of S-pretreated or control cells. These results strongly suggest that NCX has a regulatory role in cellular Ca2+ pathways in osteoblasts by modulating intracellular Ca2+ content.
Texte intégral:
1
Indice:
WPRIM
Sujet Principal:
Ostéoblastes
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Sodium
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Transduction du signal
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Membrane cellulaire
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Survie cellulaire
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Cellules cultivées
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Calcium
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Échangeur sodium-calcium
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Oligodésoxyribonucléotides antisens
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Cytoplasme
Limites du sujet:
Animals
langue:
En
Texte intégral:
Experimental & Molecular Medicine
Année:
2007
Type:
Article