Dexamethasone and cyclosporin A modulation of human retinal pigment epithelial cell monocyte chemotactic protein-1 and interleukin-8.
OBJECTIVE
To examine the modulation of interleukin-1 beta (IL-1 beta)- and tumor necrosis factor-alpha (TNF-alpha)-stimulated monocyte chemotactic protein-1 (MCP-1) and interleukin-8 (IL-8) secretion and transcription in human retinal pigment epithelial (HRPE) cells by dexamethasone (DEX) and cyclosporin A (CSA).


METHODS
Cultured HRPE cells were stimulated with IL-1 beta (0.2 to 20 ng/ml) or TNF-alpha (0.2 to 20 ng/ml) for 8 or 24 hours without (control) and with DEX (10(-8) to 10(-6) M) or with CSA (0.3 to 30 ng/ml). Secreted levels of HRPE MCP-1 and IL-8 were measured in the media using enzyme-linked immunosorbent assay (ELISA). Both MCP-1 and IL-8 mRNA were analyzed by Northern blot.


RESULTS
Although DEX (10(-8) to 10(-6) M) inhibited IL-1 beta-stimulated MCP-1 and IL-8 production, it did not inhibit TNF-alpha-stimulated chemokine secretion. In contrast, CSA significantly inhibited TNF-alpha-stimulated, but not IL-1 beta-stimulated, HRPE MCP-1 and IL-8 secretion. Both DEX and CSA inhibitions showed dose dependence. Northern blot analysis of HRPE steady state MCP-1 and IL-8 mRNA corroborated the ELISA measurements of secreted MCP-1 and IL-8.


CONCLUSIONS
Although DEX and CSA inhibit HRPE MCP-1 and IL-8 secretion, this is dependent on whether the inducing inflammatory mediator is IL-1 beta or TNF-alpha. IL-1 beta-induced chemokine secretion is sensitive to DEX, whereas MCP-1 and IL-8 induced by TNF-alpha are inhibited by CSA. This information may be useful in explaining in vivo observations and in suggesting targeted clinical treatments and combinations of immunosuppressive agents.
Kurtz
R M
RM
Department of Ophthalmology (Kellogg Eye Center), University of Michigan, Ann Arbor 48105, USA.
Elner
V M
VM
Bian
Z M
ZM
Strieter
R M
RM
Kunkel
S L
SL
Elner
S G
SG
D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D015152:Blotting, Northern; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D016572:Cyclosporine / Q000494:pharmacology*; D015342:DNA Probes / Q000737:chemistry; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000494:pharmacology; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D010857:Pigment Epithelium of Eye / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D018932:Chemokine CCL2; D015342:DNA Probes; D007166:Immunosuppressive Agents; D007375:Interleukin-1; D016209:Interleukin-8; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D003907:Dexamethasone; D016572:Cyclosporine