Association of glucocorticoids and cyclosporin A or rapamycin prevents E-selectin and IL-8 expression during LPS- and TNFalpha-mediated endothelial cell activation.
BACKGROUND
Endothelial cell (EC) activation plays an important role in inflammation, hemostasis, and organ rejection of allogeneic and xenogeneic transplantation. These processes leads to rapid and transient up-regulation of proinflammatory molecules, such as the adhesion molecule E-selectin and the chemotactic cytokine IL-8. The purpose of this study was to investigate the specific effects of several major and potentially synergistic immunosuppressive drugs-cyclosporin A (CsA), rapamycin (Rap), and glucocorticoids (GC)-on lipopolysaccharide (LPS)- or tumor necrosis factor (TNF)alpha-induced EC activation


METHODS
The ability of immunosuppressive drugs, used alone or in combination, to prevent in vitro TNFalpha- and LPS-induced expression of E-selectin and interleukin 8 on porcine ECs, as well as their effect on leukocyte-EC interaction, were investigated. In addition, we studied the in vivo effect of these drugs after i.v. administration of recombinant TNFalpha to rats.


RESULTS
At high concentrations, which correspond to the acceptable experimental levels in primate xenograft recipients, CsA, Rap, and GC individually inhibited E-selectin protein induction in a dose-dependent manner in cultured porcine ECs treated with LPS with an additive effect when the drugs were associated. The pattern of drug-mediated inhibition was related to the stimulus used to activate ECs (i.e., LPS vs. TNFalpha). Reduced expression of E-selectin on ECs activated in the presence of the tested immunosuppressive drugs correlated with a weaker adhesion of human U937 cells to ECs. Messenger RNA analysis demonstrated that the presence of CsA, Rap, and GC during EC activation inhibited E-selectin and interleukin 8 at the gene expression level. LPS-mediated induction of IbetaBalpha expression was not observed in ECs treated with CsA, whereas GC reduced its transcripts by approximately 50%. It is interesting that in vivo studies confirmed that CsA and GC inhibited EC activation at therapeutic doses (1 mg/kg and 10 mg/kg for GC and CsA, respectively) and showed that the combination of CsA and GC efficiently prevents TNFalpha-mediated induction of E-selectin on cardiac ECs.


CONCLUSIONS
Our data show that, besides their specific immunosuppressive effects on T cells, CsA, Rap, and GC can efficiently contribute to the attenuation of EC activation in vivo and the resulting inhibition is enhanced by the association of CsA with GC.
Charreau
B
B
INSERM U437 immunointervention en Allo- et Xénotransplantation and Institut de Transplantation et de Recherche en Transplantation, CHU de Nantes, France.
Coupel
S
S
Goret
F
F
Pourcel
C
C
Soulillou
J P
JP
D000818:Animals; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology*; D015536:Down-Regulation; D004338:Drug Combinations; D019040:E-Selectin / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D015870:Gene Expression / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D020672:I-kappa B Proteins / Q000235:genetics; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D016209:Interleukin-8 / Q000037:antagonists & inhibitors*; D008070:Lipopolysaccharides / Q000494:pharmacology; D051381:Rats; D020123:Sirolimus / Q000494:pharmacology*; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D004338:Drug Combinations; D019040:E-Selectin; D005938:Glucocorticoids; D020672:I-kappa B Proteins; D007166:Immunosuppressive Agents; D016209:Interleukin-8; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D016572:Cyclosporine; D020123:Sirolimus