Mechanism of intracellular Ca(2+)-wave propagation elicited by mechanical stimulation in cultured endothelial CPAE cells.
Intra- and intercellular Ca(2+)-signaling during mechanical stimulation in calf pulmonary artery endothelial cells (CPAE) was investigated with digital fluorescence microscopy. Mechanical stimulation of a CPAE cell in a Ca(2+)-containing solution revealed a rise of the free intracellular Ca(2+)-concentration ([Ca(2+)](i)) in the mechanically stimulated cell (MS) proceeding to the neighboring (NB) cells as an intercellular Ca(2+)-wave. Experiments in Ca(2+)-free solution, containing 2mM EGTA, demonstrated that a detectable [Ca(2+)](i)-transient in the MS cell is not always a requisite for intercellular communication (IC). The Ca(2+)-wave propagation was not affected by changes in membrane potential and was not mediated by voltage-dependent Ca(2+)-channels. Ca(2+)-influx through the Ni(2+)-sensitive Ca(2+)-pathway occurred in the MS as could be assessed by Mn(2+)-quenching experiments. The intra- and intercellular Ca(2+)-wave was triggered by the release of thapsigargin-sensitive intracellular Ca(2+)-stores. Phospholipase C (PLC) inhibition by U73122 reduced the Ca(2+)-amplitude of the MS cell and almost completely inhibited the IC, indicating that the Ca(2+)-release in the MS and NB cells is PLC/inositol 1,4,5-trisphosphate (IP(3)) mediated.
Moerenhout
M
M
Laboratory of Physiology, O/N Campus Gasthuisberg, KU Leuven, Leuven, Belgium.
Vereecke
J
J
Himpens
B
B
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002417:Cattle; D002460:Cell Line; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000378:metabolism; D018613:Microscopy, Confocal; D012433:Ryanodine / Q000494:pharmacology; D013314:Stress, Mechanical; D019284:Thapsigargin / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D012433:Ryanodine; D019284:Thapsigargin; D010738:Type C Phospholipases; D002118:Calcium