Transient increases in cytosolic free calcium appear to be required for the migration of adherent human neutrophils published erratum appears in J Cell Biol 1990 Mar;110(3):861

Human neutrophils exhibit multiple increases in cytosolic free calcium concentration ( Ca2+i) spontaneously and in response to the chemoattractant N-formyl-L-methionyl-L-leucyl-L-phenylalanine (Jaconi, M. E. E., R. W. Rivest, W. Schlegel, C. B. Wollheim, D. Pittet, and P. D. Lew. 1988. J. Biol. Chem. 263:10557-10560). The function of these repetitive increases in Ca2+i, as well as the role of Ca2+ in human neutrophil migration, remain unresolved. We have used microspectrofluorometry to measure Ca2+i in single fura-2-loaded human neutrophils as they moved on poly-D-lysine-coated glass in the presence of serum. To investigate the role of Ca2+ in human neutrophil migration, we examined cells in the presence and absence of extracellular Ca2+, as well as intracellular Ca2(+)-buffered and Ca2(+)-depleted cells. In the presence of extracellular Ca2+, multiple increases and decreases in Ca2+i were frequently observed, and at least one such transient increase in Ca2+i occurred in every moving cell during chemokinesis, chemotaxis, and phagocytosis. In addition, neutrophils that extended pseudopodia and assumed a polarized morphology after plating onto a surface were always observed to exhibit Ca2+i transients even in the absence of chemoattractant. In contrast, a Ca2+i transient was observed in only one of the nonpolarized stationary cells that were examined (n = 15). Although some cells exhibited relatively periodic increases and decreases in Ca2+i, resembling the regular oscillations that have been observed in some cell types, many others exhibited increases and decreases in Ca2+i that varied in their timing, magnitude, and duration. Buffering of Ca2+i or removal of extracellular Ca2+ damped out or blocked transient increases in Ca2+i and reduced or inhibited the migration of neutrophils. Under these conditions, polarized cells were often observed to make repeated attempts at migration, but they remained anchored at their rear. These data suggest that transient increases in Ca2+i may be required for the migration of human neutrophils on poly-D-lysine-coated glass in the presence of serum by allowing them to release from previous sites of attachment.