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Mediators of Inflammation
Volume 1, Issue 6, Pages 385-390

Human keratinocyte sensitivity towards inflammatory cytokines varies with culture time

1Department of Pharmacology, Medical Biological Laboratory, T.N.O., P.O. Box 45, Rijswijk 2280 AA, The Netherlands
2Department of Pharmacology, Erasmus University, P.O. Box 1738, Rotterdam 3000 DR, The Netherlands

Copyright © 1992 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Proliferating keratinocyte cultures have been reported to synthesize higher concentrations of prostaglandin (PG) E than confluent ones. As interleukin-1 (IL-1) stimulates keratinocyte PGE synthesis we investigated whether the degree of confluency of the keratinocyte culture modified the response of the cells to IL-1. It was found that IL-1α (100 U/ml) stimulated PGE2 synthesis by proliferating (7 days in culture) but not differentiating (14 days in culture) keratinocytes. Similar effects were observed using tumour necrosis factor-α. Both arachidonic acid (AA) and the calcium ionophore A23187 stimulated PGE2 synthesis by 7 and 14 day cultures although the increase was greatest when 7 day cultures were used. Our data indicate that there is a specific down-regulation of the mechanism(s) by which some inflammatory cytokines stimulate keratinocyte eicosanoid synthesis as cultured keratinocytes begin to differentiate.