RESUMEN
OBJECTIVE: This study was performed to characterize selected rhodanine derivatives as potential preclinical disease-modifying drugs for experimental osteoarthritis (OA) in mice. METHODS: Three rhodanine derivatives, designated rhodanine (R)-501, R-502, and R-503, were selected as candidate OA disease-modifying drugs. Their effects were evaluated by intra-articular (IA) injection in OA mouse models induced by DMM (destabilization of the medial meniscus) or adenoviral overexpression in joint tissues of hypoxia-inducible factor (HIF)-2α or zinc importer ZIP8. The regulatory mechanisms impacted by the rhodanine derivatives were examined in primary-culture chondrocytes and fibroblast-like synoviocytes (FLS). RESULTS: All three rhodanine derivatives inhibited OA development caused by DMM or overexpression of HIF-2α or ZIP8. Compared to vehicle-treated group, for example, IA injection of R-501 in DMM-operated mice reduced median OARSI grade from 3.78 (IQR 3.00-5.00) to 1.89 (IQR 0.94-2.00, P = 0.0001). R-502 and R-503 also reduced from 3.67 (IQR 2.11-4.56) to 2.00 (IQR 1.00-2.00, P = 0.0030) and 2.00 (IQR 1.83-2.67, P = 0.0378), respectively. Mechanistically, the rhodanine derivatives inhibited the nuclear localization and transcriptional activity of HIF-2α in chondrocytes and FLS. They did not bind to Zn2+ or modulate Zn2+ homeostasis in chondrocytes or FLS; instead, they inhibited the nuclear localization and transcriptional activity of the Zn2+-dependent transcription factor, MTF1. HIF-2α, ZIP8, and interleukin-1ß could upregulate matrix-degrading enzymes in chondrocytes and FLS, and the rhodanine derivatives inhibited these effects. CONCLUSION: IA administration of rhodanine derivatives significantly reduced OA pathogenesis in various mouse models, demonstrating that these derivatives have disease-modifying therapeutic potential against OA pathogenesis.