ISSN:
0730-2312
Keywords:
intracellular Ca2+
;
1β25-(OH)2D3
;
ROS 17/2.8
;
OC mRNA
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
We have previously shown that one of the rapid nongenomic actions of 1α,25-dihydroxyvitamin D3 (1α,25-(OH)2D3), the increase in intracellular calcium (Ca2+), accompanies the increased osteocalcin (OC) mRNA steady-state levels in rat osteosarcoma cells. To determine the functional significance of the nongenomic actions, we have measured changes in intracellular Ca2+ as an indicator of the rapid effects and have assessed the effect of inhibition of the rapid increase in cellular Ca2+ by the inactive epimer, 1β,25-dihydroxyvitamin D3 (1β,25-(OH)2D3) on OC mRNA steady-state levels and transcription. 1β,25-dihydroxyvitamin D3 inhibited 1α,25-(OH)2D3 induced increases in intracellular Ca2+ and OC mRNA transcription at 1 hr and OC mRNA steady state levels at 3 hr. 1β,25-Dihydroxyvitamin D3 did not alter the binding of the vitamin D receptor complex to the vitamin D responsive element of the OC gene. The results demonstrate the functional importance of the rapid, nongenomic actions of 1α,25-(OH)2D3 in the genomic activation of the OC gene by the hormone in rat osteoblast-like cells, perhaps by modifying subtle structural and/or functional properties of the vitamin D-receptor DNA complex or by affecting other protein DNA interactions that support OC gene transcription. © 1992 Wiley-Liss, Inc.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcb.240500203
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