Elevated O-GlcNAc modification of NF-ĸB increases TNF-ɑ mediated activation of inflammation in Rheumatoid Arthritis.

다국어 초록 (Multilingual Abstract)

O-linked N-acetylglucosamine (O-GlcNAc) modification is unique glycosylations and it can occur exclusively in nucleus and cytoplasm. O-GlcNAc is attached onto a serine or threonine residue of a protein by O-GlcNAc transferase (OGT) and detached by O-GlcNAcase (OGA) under dynamic regulations by a variety of conditions. O-GlcNAcylation is associated with several clinical situations including cancers and inflammatory diseases. The effect of O-GlcNAcylation of subunits of nuclear factor-ĸB on its transcriptional activity has been reported to date. Interestingly, O-GlcNAc modification of NF-ĸB exhibited reciprocal results on its activity depending on different cell types: increased O-GlcNAcylation elevated the activity of NF-ĸB in pancreatic cancer cells, while aortic smooth muscle cells showed negative correlation between O-GlcNAcylation and NF-ĸB activity In Rheumatoid Arthirtis (RA), NF-ĸB is the novel regulator of pro-inflammatory cytokines mediating synovitis, long-term cartilage degradation and bone erosion. We hypothesize that the alteration in the activity of NF-ĸB resulting from its O-GlcNAcylation might affect the severity of RA. There was no report on the effect of O-GlcNAcylation of NF-ĸB on its activity in RA. We used in vitro synoviocytes and in vivo in mice with collagen induced arthritis (CIA) and investigated the inflammatory potential of O-GlcNAcylation of P65, one of subunits of NF-ĸB, in the pathogenesis of RA.