Activation of human neutrophils after contact with cellulose-based haemodialysis membranes: intracellular calcium signalling in single cells.
OBJECTIVE
In vitro contact of human leukocytes with cellulose-based dialysis membranes under complement-independent conditions results in activation of various leukocyte functions. To analyse signals involved in the mechanism of cell activation, we measured changes in cytosolic free calcium ([Ca2+]i) in individual human blood neutrophils (PMN) upon contact with flat sheet haemodialysis membranes.


RESULTS
By confocal laser-scanning microscopy (CLSM), changes in [Ca2+]i were monitored in Fluo-3-labelled cells up to 10 min after contact with a regenerated cellulose (RC) membrane. Multiple [Ca2+]i transients were observed for cells in contact with RC; biostochastic analysis showed that up to 67% of the PMN responded with a high increase in [Ca2+]i, the rest were low- or non-responding cells. After contact with the new synthetic polycarbonate-polyether (PC-PE) membrane only non-responding cells were seen, indicating reduced cellular contact activation. The increase in [Ca2+]i of cells on RC could be inhibited by 5mM L-fucose. This monosaccharide was recently found to be present in cellulose-based polymers in picomolar concentrations.


CONCLUSIONS
The data supports the hypothesis that dialysis-membrane-associated L-fucose residues participate in complement-independent leukocyte activation during haemodialysis therapy.
Hänsch
G M
GM
Institut für Immunologie, Heidelberg, Germany.
Karnaoukhova
S
S
Chang
S H
SH
Rus
H
H
Nicolescu
F
F
Deppisch
R
R
Meissner
C
C
Ludwig
H
H
Ritz
E
E
D001672:Biocompatible Materials / Q000494:pharmacology*; D002118:Calcium / Q000032:analysis / Q000502:physiology; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology; D002482:Cellulose / Q000031:analogs & derivatives* / Q000494:pharmacology; D003600:Cytosol / Q000737:chemistry; D005643:Fucose / Q000494:pharmacology; D006801:Humans; D008567:Membranes, Artificial; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology* / Q000648:ultrastructure; D011108:Polymers / Q000494:pharmacology; D006435:Renal Dialysis; D015398:Signal Transduction
D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011108:Polymers; D005643:Fucose; C049723:polycarbonate-polyether copolymer; D009240:N-Formylmethionine Leucyl-Phenylalanine; D002482:Cellulose; C009865:cuprammonium cellulose; D002118:Calcium