Linked Life Data

15913555

Source:http://linkedlifedata.com/resource/pubmed/id/15913555

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-5-31
pubmed:abstractText
Taste and salivary secretion disorders have been linked to zinc deficiency, indeed zinc is found in secretory granules in the salivary gland. The signaling role for the zinc release in this tissue, however, is poorly understood. Here, we address the signaling pathways and physiological role of the zinc-sensing receptor, ZnR, in the ductal salivary gland cell line, HSY. Exposure of these cells to zinc triggered intracellular Ca2+ release from thapsigargin-sensitive stores. The G alpha q inhibitor, YM-254890 (1 microM), eliminated the Zn2+-dependent Ca2+ response, demonstrating that ZnR is a G alpha q-coupled receptor. Dose-response curves yielded an apparent K0.5 of 36 microM and a Hill coefficient of 7 in the absence of extracellular Ca2+, and K0.5 of 55 microM with a Hill coefficient of 3 in its presence. This indicates that although Zn2+ is essential for ZnR activation, Ca2+ may affect the receptor co-operativity. The homologous desensitization pattern of ZnR was characterized by pre-exposure of cells to Zn2+ at concentrations found to activate the receptor. Re-exposure of cells to Zn2+ elicited an attenuated Zn2+-dependent Ca2+ response for at least 3 h, indicating that the ZnR is strongly desensitized by Zn2+. Finally, we studied the paracrine affects of ZnR using a co-culture consisting of the HSY cells and vascular smooth muscle cells (VSMCs). While no Zn2+-dependent Ca2+ release was observed in VSMC alone, application of Zn2+ to the co-culture induced a Ca2+ rise in both HSY cells and VSMC. This Ca2+ rise was inhibited by the ATP scavenger, apyrase. Taken together, our results demonstrate that ZnR activity is monitored in salivary cells and is modulated by extracellular Ca2+. We further show that ZnR enhances secretion of ATP, thereby linking zinc to key signaling pathways involved in modification of salivary secretions by the ductal cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
332
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
845-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
The extracellular zinc-sensing receptor mediates intercellular communication by inducing ATP release.
pubmed:affiliation
Department of Morphology, Zlotowski Center for Neuroscience, Ben Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't