Several types of arthritis share the common feature that the generation of inflammatory mediators leads to joint cartilage degradation. However, the shared mechanism is largely unknown. H2BK120ub1 was reportedly involved in various inflammatory diseases but its role in the shared mechanism in inflammatory joint conditions remains elusive. The present study demonstrated that levels of cartilage degradation, H2BK120ub1, and its regulator WW domain-containing adapter protein with coiled-coil (WAC) were increased in cartilage in human rheumatoid arthritis (RA) and osteoarthritis (OA) patients as well as in experimental RA and OA mice. By regulating H2BK120ub1 and H3K27me3, WAC regulated the secretion of inflammatory and cartilage-degrading factors. WAC influenced the level of H3K27me3 by regulating nuclear entry of the H3K27 demethylase KDM6B, and acted as a key factor of the crosstalk between H2BK120ub1 and H3K27me3. The cartilage-specific knockout of WAC demonstrated the ability to alleviate cartilage degradation in collagen-induced arthritis (CIA) and collagenase-induced osteoarthritis (CIOA) mice. Through molecular docking and dynamic simulation, doxercalciferol was found to inhibit WAC and the development of cartilage degradation in the CIA and CIOA models. Our study demonstrated that WAC is a key factor of cartilage degradation in arthritis, and targeting WAC by doxercalciferol could be a viable therapeutic strategy for treating cartilage destruction in several types of arthritis.

Objective To investigate the changes of serum cardiac-specific troponin I (cTnI) level in patients after lung transplantation. Methods Clinical data of patients undergoing lung transplantation in our hospital from December 2016 to December 2022 were retrospectively analyzed. The relationship between postoperative serum cTnI level and clinical characteristics were explored. Results Finally 20 patients were collected, including 15 males and 5 females with an average age of (51.65±12.79) years. The serum cTnI level was significantly increased after lung transplantation. The serum cTnI reached the highest level on the first day after transplantation, and significantly decreased from the third day after transplantation. The serum cTnI levels in patients with obstructive pulmonary disease and bilateral lung transplantation were significantly higher than those in patients with restrictive pulmonary disease and unilateral lung transplantation on the day after surgery and on the first day after transplantation. Conclusion Transient myocardial injury can occur after lung transplantation, which is characterized by an abnormal increase in serum cTnI level.