β1,4-Galactosyltransferase-I contributes to the inflammatory processes in synovial tissue of patients with rheumatoid arthritis.

The aim of the study is to examine the expression and possible biological function of β1,4-galactosyltransferase-I (β1,4-GalT-I) in synovial tissue from rheumatoid arthritis (RA) patients. Synovial tissue samples from twelve RA patients were stained for β1,4-GalT-I. Samples from seven patients with osteoarthritis (OA) and eight healthy people were obtained as controls. Real-time PCR or western blot analysis was used to observe the expression of β1,4-GalT-I and E-selectin. Cellular colocalization of β1,4-GalT-I, galactose-containing glycans and other molecules was analyzed by double immunofluorescence. Expression of β1,4-GalT-I and galactose-containing glycans increased in synovial tissue of RA patients compared with OA patients and healthy controls. Most galactose-containing glycans and β1,4-GalT-I were expressed in inflammatory cells. E-selectin overexpressed and was correlated with galactose-containing glycans in RA synovial tissue. These results suggested that β1,4-GalT-I may play an important role in the inflammatory processes in synovial tissue of patients with rheumatoid arthritis.