To determine the role of α(1,2)-linked fucosylation of proteins by fucosyltransferase 1 (FUT1) in rheumatoid arthritis (RA) angiogenesis.
Analysis of α(1,2)-linked fucosylated proteins in synovial tissue (ST) samples was performed by immunohistologic staining. Expression of α(1,2)-linked fucosylated angiogenic chemokine in synovial fluid (SF) was determined by immunoprecipitation and lectin blotting. To determine the angiogenic role of α(1,2)-linked fucosylated proteins in RA, we performed human dermal microvascular endothelial cell (HMVEC) chemotaxis and Matrigel assays using sham-depleted and α(1,2)-linked fucosylated protein-depleted RA SF samples. To examine the production of proangiogenic chemokines by FUT1 in HMVECs, cells were transfected with FUT1 sense or antisense oligonucleotides, and enzyme-linked immunosorbent assay was performed. We then studied mouse lung endothelial cell (EC) chemotaxis using wild-type and FUT1 gene-deficient mouse lung ECs.
RA ST endothelial cells showed high expression of α(1,2)-linked fucosylated proteins compared to normal ST. The expression of α(1,2)-linked fucosylated monocyte chemoattractant protein 1 (MCP-1)/CCL2 was significantly elevated in RA SF compared with osteoarthritis SF. Depletion of α(1,2)-linked fucosylated proteins in RA SF induced less HMVEC migration and tube formation than occurred in sham-depleted RA SF. We found that blocking FUT1 expression in ECs resulted in decreased MCP-1/CCL2 and RANTES/CCL5 production. Finally, we showed that FUT1 regulates EC migration in response to vascular endothelial cell growth factor.
Our findings indicate that α(1,2)-linked fucosylation by FUT1 may be an important new target for angiogenic diseases such as RA.