Expression Of β1, 4-galactosyltransferase-Ⅰ In Synovial Tissue Of Patients With Rheumatoid Arthritis

Objective The aim of the study is to examine the expression and possible biological function ofβ1,4-galactosyltransferase-I (β1,4-GalT-I) in synovial tissue of knee joint from rheumatoid arthritis (RA) patients.Methods Synovial tissue samples from twelve RA patients were stained forβ1,4-GalT-I. Samples from seven patients with osteoarthritis (OA) and eight healthy people were obtained as controls. The mRNA levels ofβ1,4-GalT-I were measured by real-time PCR and western blot analysis was used to observe the expression ofβ1,4-GalT-I and E-selectin in protein level. Lectin-blotting was used to detect the expression of galactose-containing glycans in RA synovial tissue. Cellular colocalization ofβ1,4-GalT-I, galactose-containing glycans and other molecules was analyzed by double immunofluorescence. Double labeling immunofluorescence and immunoprecipitation were used to assess the specificity of interactions between E-selectin and galactose-containing glycans in synovial tissue of RA patients.Resultsβ1,4-GalT-I staining was detectable in 87% of the RA synovial tissue. Expression ofβ1,4-GalT-I and galactose-containing glycans increased in synovial tissue of RA patients compared with OA patients and healthy controls. Most of galactose-containing glycans andβ1,4-GalT-I were expressed in inflammatory cells. E-selectin overexpressed in Fibroblast-and Macrophage-like synoviocytes of RA synovial tissue. Moreover, E-selectin was correlated with galactose-containing glycans in RA synovial tissue.Conclusion These results suggested thatβ1,4-GalT-I may play an important role in the inflammatory processes in synovial tissue of patients with rheumatoid arthritis.