Tumor necrosis factor-α up-regulates the expression of β1,4-galactosyltransferase-I in human fibroblast-like synoviocytes.
β1,4-Galactosyltransferase-I (β1,4-GalT-I), which transfers galactose to the terminal N-acetylglucosamine of N- and O-linked glycans in a β1,4-linkage, is considered to be the major galactosyltransferase among the seven members of the subfamily responsible for β4 galactosylation. We previously reported, for the first time, that β1,4-GalT-I may play an important role in the inflammatory processes in synovial tissue of patients with rheumatoid arthritis (RA). In this study, we analyzed whether β1,4-GalT-I expression correlates with the expression of tumor necrosis factor-α (TNF-α) in RA. We show firstly the overexpression and co-localization of β1,4-GalT-I and TNF-α in synovial tissue of RA patients. Then, lipopolysaccharide (LPS) induces β1,4-GalT-I mRNA up-regulation in fibroblast-like synoviocytes (FLSs) through endogenous TNF-α overexpression. In addition, we observed that not only endogenous TNF-α but also exogenous TNF-α induced β1,4-GalT-I mRNA production in FLSs, and TNF-α-knockdown reverses the up-regulation of β1,4-GalT-I in FLSs induced by LPS or TNF-α. These results suggest that TNF-α contributes to the up-regulation of β1,4-GalT-I mRNA in human FLSs.
Xu
Dawei
D
Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, 226001, People's Republic of China.
Cui
Zhiming
Z
Liu
Wei
W
Tao
Ran
R
Tao
Tao
T
Shen
Aiguo
A
Wang
Youhua
Y
D000368:Aged; D001172:Arthritis, Rheumatoid / Q000473:pathology; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005700:Galactosyltransferases / Q000235:genetics*; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000187:drug effects; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*; D015854:Up-Regulation / Q000235:genetics*
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D005700:Galactosyltransferases; C119701:beta-1,4-galactosyltransferase I