Macrophage migration inhibitory factor increases leukocyte-endothelial interactions in human endothelial cells via promotion of expression of adhesion molecules.
Macrophage migration inhibitory factor (MIF) has been shown to promote leukocyte-endothelial cell interactions, although whether this occurs via an effect on endothelial cell function remains unclear. Therefore, the aims of this study were to examine the ability of MIF expressed by endothelial cells to promote leukocyte adhesion and to investigate the effect of exogenous MIF on leukocyte-endothelial interactions. Using small interfering RNA to inhibit HUVEC MIF production, we found that MIF deficiency reduced the ability of TNF-stimulated HUVECs to support leukocyte rolling and adhesion under flow conditions. These reductions were associated with decreased expression of E-selectin, ICAM-1, VCAM-1, IL-8, and MCP-1. Inhibition of p38 MAPK had a similar effect on adhesion molecule expression, and p38 MAPK activation was reduced in MIF-deficient HUVECs, suggesting that MIF mediated these effects via promotion of p38 MAPK activation. In experiments examining the effect of exogenous MIF, application of MIF to resting HUVECs failed to induce leukocyte rolling and adhesion, whereas addition of MIF to TNF-treated HUVECs increased these interactions. This increase was independent of alterations in TNF-induced expression of E-selectin, VCAM-1, and ICAM-1. However, combined treatment with MIF and TNF induced de novo expression of P-selectin, which contributed to leukocyte rolling. In summary, these experiments reveal that endothelial cell-expressed MIF and exogenous MIF promote endothelial adhesive function via different pathways. Endogenous MIF promotes leukocyte recruitment via effects on endothelial expression of several adhesion molecules and chemokines, whereas exogenous MIF facilitates leukocyte recruitment induced by TNF by promoting endothelial P-selectin expression.
Cheng
Qiang
Q
Department of Medicine, Monash Medical Centre, Centre for Inflammatory Diseases, Monash University, Clayton, Victoria, Australia.
McKeown
Sonja J
SJ
Santos
Leilani
L
Santiago
Fernando S
FS
Khachigian
Levon M
LM
Morand
Eric F
EF
Hickey
Michael J
MJ
D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002450:Cell Communication / Q000187:drug effects*; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000378:metabolism; D019040:E-Selectin / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D036904:Leukocyte Rolling / Q000187:drug effects; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008263:Macrophage Migration-Inhibitory Factors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D034622:RNA Interference; D048069:Tumor Necrosis Factors / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism
C111835:CCL2 protein, human; D015815:Cell Adhesion Molecules; D018932:Chemokine CCL2; D019040:E-Selectin; D015850:Interleukin-6; D016209:Interleukin-8; D008263:Macrophage Migration-Inhibitory Factors; D048069:Tumor Necrosis Factors; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D020928:Mitogen-Activated Protein Kinases