Cytotoxic response of sinusoidal endothelial cells to polymorphonuclear leukocytes and its potential implication in hypoxia-reoxygenation injury.
OBJECTIVE
Interactions between polymorphonuclear leukocytes (PMN) and sinusoidal endothelial cells (SEC) may contribute to ischemia-reperfusion injury. The aim of the study was to determine the influence of PMN hypoxia-reoxygenation and degranulation, on SEC toxic response.


METHODS
PMNs collected from rat pleural cavity underwent hypoxia- reoxygenation or N-formyl-methionyl-leucyl-phenylalanine (fMLP) degranulation treatment, and were then separated from their conditioned medium. Rat SECs were incubated either with PMNs in coculture or with their conditioned medium, for 210 min. Oxidative metabolism in PMNs was measured by chemiluminescence. LDH release and elastase activity were measured in SEC supernatants.


RESULTS
PMN-conditioned medium induced an increase in LDH release in SECs. Hypoxia-reoxygenation of PMNs induced an increase in their chemiluminescent response without increasing the cytotoxic effect of their conditioned medium. By contrast, the cytotoxic effect of conditioned medium was increased following PMN treatment with fMLP. In the latter case, cytotoxicity was combined with a rise in the elastase activity released in the supernatants, but was not reduced by inhibitors of elastase or of other proteases.


CONCLUSIONS
The results indicate that toxic products are released, at least in part through degranulation, by PMNs, and induce cytotoxicity in SECs. This mechanism may contribute to SEC injury during hypoxia-reoxygenation.
Lasnier
E
E
Service de Biochimie A, INSERM U 402, Hôpital Saint-Antoine, AP-HP, Paris, Service de Biochimie A, Hôtel Dieu, AP-HP, Paris, CNRS URA 1534, Hôpital Cochin, Paris, France. elisabeth.lasnier@sat.ap-hop-paris.fr
Blanc
M C
MC
Housset
C
C
Rey
C
C
Roch-Arveiller
M
M
Vaubourdolle
M
M
D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects; D015687:Cell Hypoxia; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D019272:Leukocyte Elastase / Q000378:metabolism; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology
D017077:Culture Media, Conditioned; D017382:Reactive Oxygen Species; D009240:N-Formylmethionine Leucyl-Phenylalanine; D007770:L-Lactate Dehydrogenase; D019272:Leukocyte Elastase