Apoptosis of Rheumatoid Arthritis Fibroblast-Like Synoviocytes: Possible Roles of Nitric Oxide and the Thioredoxin 1
Figure 1
The proposed pathway for the accumulation of Trx-S2 in RA-FLS. Under normal conditions, Trx1-(SH)2 reduces disulfide bonds in its substrates to form free thiols, while Trx1-(SH)2 is oxidized to Trx1-S2 simultaneously. TrxR1 further converts the disulfide bonds in Trx1-S2 to Trx1-(SH)2 in the presence of NADPH. However, under elevated reactive oxygen species (ROS) in RA-FLS, the oxidized form of TrxR1 is accumulated, which reduces the activity of TrxR1 and causes the accumulation of Trx1-S2 in RA-FLS.
