Methotrexate inhibits proliferation and regulation of the expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 by cultured human umbilical vein endothelial cells.
BACKGROUND
The mechanism by which a low dose of methotrexate (MTX) works to treat psoriasis is not clear. The overexpression of cell adhesion molecules on dermal vessels is important in the pathogenesis of psoriasis and is probably induced by upregulation of tumour necrosis factor (TNF)-alpha.


OBJECTIVE
To determine the effects of MTX at concentrations comparable with in vivo levels after the administration of low-dose MTX to human umbilical vein endothelial cells (HUVEC) on the growth and expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1).


METHODS
Cell proliferation assay, immunostaining, immunoblotting, cell enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed to examine the effects of MTX on HUVEC.


RESULTS
MTX inhibited the proliferation of HUVEC at 10-7 mol L-1 and 10-6 mol L-1 without showing cytotoxic effects. It also inhibited TNF-alpha-induced ICAM-1 and VCAM-1 expression by HUVEC at 10-6 mol L-1. The inhibitory effect of MTX was more pronounced on ICAM-1 expression than on VCAM-1 expression. RT-PCR analysis revealed that TNF-alpha-induced ICAM-1 gene expression was strongly downregulated by MTX.


CONCLUSIONS
Low-dose MTX may act on psoriasis by suppressing the TNF-alpha-induced expression of ICAM-1 and VCAM-1 by vascular endothelial cells. Inhibition of neovascularization may be another mechanism of action of MTX.
Yamasaki
E
E
Department of Dermatology, St Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, 216-8511, Japan. hifu@marianna-u.ac.jp
Soma
Y
Y
Kawa
Y
Y
Mizoguchi
M
M
D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D008727:Methotrexate / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
D007166:Immunosuppressive Agents; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D008727:Methotrexate