Dry skin induced by rheumatoid arthritis (RA) causes itching, which negatively influences a patient's quality of life. We previously reported that mast cells are related to dry skin in arthritic mice. However, the mechanism of mast cell activation is unclear. In this study, we examined the mechanism underlying the formation of dry skin induced by mast cells in arthritis that involves thymic stromal lymphopoietin (TSLP), neutrophils, reactive oxygen species (ROS), and glucocorticoids.
Mice with DBA/1JJmsSlc collagen-induced arthritis were treated with inhibitors or neutralizing antibodies. We measured transepidermal water loss (TEWL) to examine the modulating signal of mast cells.
TEWL, the number of mast cells, and the plasma levels of TSLP, ROS, and corticosterone in the arthritic mice were increased when compared with the control mice. However, the mice treated with TSLP- and neutrophil-neutralizing antibodies and ROS and glucocorticoid receptor inhibitors (N-acetyl-L-cysteine [NAC] and RU-486, respectively) experienced an improvement. The ameliorating effect was most remarkable following treatment with NAC + RU-486.
This study suggested that inhibiting ROS and glucocorticoids is important to ameliorate dry skin in arthritis, which may provide a novel treatment option for dry skin in RA patients.