title: Intracellular Ca2+ stores are essential for injury induced Ca2+ signaling and re-endothelialization.
abstract: Endothelialization repairs the lining of damaged vasculature and is a key process in preventing thrombosis and restenosis. It has been demonstrated that extracellular calcium ([Ca2+](o)) influx is important for subsequent endothelialization. The role of intracellular Ca2+ stores in mechanical denudation induced intracellular calcium ([Ca2+](i)) rise and endothelialization remains to be demonstrated. Using monolayer culture of a human endothelial cell line (human umbilical vein endothelial cell, HUVEC), we investigated [Ca2+](i) wave propagation and re-endothelialization following mechanical denudation. Consistent with previous reports for other types of cells, mechanical denudation induces calcium influx, which is essential for [Ca2+](i) rise and endothelialization. Moreover, we found that intracellular Ca(2+) stores are also essential for denudation induced [Ca2+](i) wave initiation and propagation, and the subsequent endothelialization. Thapsigargin which depletes intracellular Ca2+ stores completely abolished [Ca2+](i) wave generation and endothelialization. Xestospongin C (XeC), which prevents Ca2+ release from intracellular Ca2+ stores by inhibition of inositol 1,4,5-trisphosphate (IP(3)) receptor, inhibited intercellular Ca2+ wave generation and endothelialization following denudation. Purinergic signaling through a suramin sensitive mechanism and gap junction communication also contribute to in intercellular Ca(2+) wave propagation and re-endothelialization. We conclude that intracellular Ca2+ stores, in addition to extracellular Ca2+, are essential for intracellular Ca2+ signaling and subsequent endothelialization following mechanical denudation.
authors.affiliation: School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Petr
authors.initials: P
authors.lastname: Walczysko
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
mesh_terms: D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D003035:Cobalt / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D011983:Receptors, Purinergic / Q000378:metabolism
chemical_list: D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D011983:Receptors, Purinergic; D003035:Cobalt; C018021:cobaltous chloride