Abstract
1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) induces the differentiation of normal human keratinocytes, in part by increasing their basal intracellular calcium levels (Cai) over a period of hours. Agonists such as ATP acting through membrane receptors cause an immediate but transient increase in Cai accompanied by an increase in inositol trisphosphate (IP3). Treatment of keratinocytes for 24 h with 1 nM 1,25(OH)2D3 resulted in a two- to four-fold potentiation of the Cai response of these cells to ATP. This potentiation was inhibitable with cycloheximide, unaccompanied by a change in total intracellular calcium pools, but associated with an increase in basal IP3 levels and ATP-stimulated IP3 production. Treatment with 1,25(OH)2D3 raised the protein and mRNA levels of phospholipase C isoenzymes, particularly phospholipase C-beta 1 in a dose-dependent manner. These studies indicate that 1,25(OH)2D3 modulates the keratinocyte signal transduction pathway by induction of phospholipase isoenzymes, a previously undescribed action for this hormone.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.