Thalidomide inhibits inflammatory and angiogenic activation of human intestinal microvascular endothelial cells (HIMEC).
The glutamic acid derivative thalidomide is a transcriptional inhibitor of TNF-alpha but is also known to affect human blood vessels, which may underlie its teratogenicity. Thalidomide has been used in the treatment of refractory Crohn's disease (CD), but the therapeutic mechanism is not defined. We examined the effect of thalidomide on primary cultures of human intestinal microvascular endothelial cells (HIMEC), the relevant endothelial cell population in inflammatory bowel disease (IBD), to determine its effect on endothelial activation, leukocyte interaction, and VEGF-induced angiogenesis. HIMEC cultures were pretreated with thalidomide before activation with either TNF-alpha/LPS or VEGF. A low-shear-stress flow adhesion assay with either U-937 or whole blood was used to assess HIMEC activation following TNF-alpha/LPS, and a Wright's stain identified adherent leukocytes. Expression of cell adhesion molecules (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) was assessed using radioimmunoassay. Effects of thalidomide on NF-kappaB activation, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) expression in TNF-alpha/LPS-activated HIMEC were determined by RT-PCR and Western blotting. Thalidomide blocked adhesion of both U-937 and whole blood leukocytes by 50% in HIMEC, inhibiting binding of all classes of leukocytes. Thalidomide also blocked NF-kappaB and cell adhesion molecule expression in HIMEC. In marked contrast, thalidomide did not affect either iNOS or COX-2 expression, two key molecules that play a role in the downregulation of HIMEC activation. VEGF-induced HIMEC transmigration, growth, proliferation, tube formation, and Akt phosphorylation were significantly inhibited by thalidomide. In summary, thalidomide exerted a potent effect on HIMEC growth and activation, suggesting that it may also function via an endothelial mechanism in the treatment of CD.
Rafiee
Parvaneh
P
Dept. of Surgery, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA. prafiee@mcw.edu
Stein
Daniel J
DJ
Nelson
Victoria M
VM
Otterson
Mary F
MF
Shaker
Reza
R
Binion
David G
DG
D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003424:Crohn Disease / Q000188:drug therapy* / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D019040:E-Selectin / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007422:Intestines / Q000098:blood supply; D007962:Leukocytes / Q000166:cytology; D008070:Lipopolysaccharides / Q000494:pharmacology; D055806:Microvessels / Q000166:cytology; D016328:NF-kappa B / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000473:pathology; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D013792:Thalidomide / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology
D020533:Angiogenesis Inhibitors; D019040:E-Selectin; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; C467484:VEGFA protein, human; D019010:Vascular Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A; D018799:Intercellular Adhesion Molecule-1; D013792:Thalidomide; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D051057:Proto-Oncogene Proteins c-akt