Endothelial [Ca(2+)](i) signaling during transmigration of polymorphonuclear leukocytes.
Vascular endothelium plays an important role in regulating the transendothelial migration of polymorphonuclear leukocytes (PMNs). In this study, the intracellular calcium ion ([Ca(2+)](i)) signaling of endothelial cells (ECs) during PMN transmigration was examined at the single-cell level. Human umbilical vein ECs were cultured on a thin layer of collagen gel. The ECs were labeled with fura-2, immersed in formyl-Met-Leu-Phe, and subsequently perfused with fresh buffer to establish a gradient of chemoattractant across the EC monolayer. The entire process of PMN rolling on, adhering to, and transmigrating across the EC monolayer was recorded under both phase-contrast and fluorescence optics. The data showed the following: (1) At high concentration (approximately 3 x 10(6)/mL), both PMN suspension and its supernatant stimulated frequent EC [Ca(2+)](i) elevations across the monolayer; (2) when used at lower concentration (approximately 5 x 10(5)/mL) to avoid the interference of soluble factors, PMN transmigration, but not rolling or adhesion, was accompanied by EC [Ca(2+)](i) elevation; (3) the latter EC [Ca(2+)](i) elevation occurred simultaneously in ECs adjacent to the transmigration site, but not in those that were not in direct contact with the transmigrating PMNs; (4) this EC [Ca(2+)](i) elevation was an initial and required event for PMN transmigration; and (5) PMNs pretreated with 5,5'-dimethyl-1, 2-bis(2-aminophenoxy)ethane-N, N, N', N'-tetraacetic acid transmigrated with the accompanying EC [Ca(2+)](i) elevation, but they became elongated in the collagen gel. In conclusion, PMNs induce adjacent EC [Ca(2+)](i) signaling, which apparently mediates the "gating" step for their subsequent transmigration. (Blood. 2000;96:3816-3822)
Su
W H
WH
Department of Physiology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan, Republic of China.
Chen
H I
HI
Huang
J P
JP
Jen
C J
CJ
D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002450:Cell Communication; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D018920:Coculture Techniques; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D016257:Fura-2; D006801:Humans; D008856:Microscopy, Fluorescence; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology* / Q000378:metabolism; D013997:Time Factors; D014471:Umbilical Veins / Q000166:cytology
D009240:N-Formylmethionine Leucyl-Phenylalanine; D002118:Calcium; D016257:Fura-2