RCGD 423

**RCGD 423** is a small molecule modulator of glycoprotein 130 (gp130) signaling that promotes cartilage regeneration and inhibits degeneration. It binds to domain 2 of gp130, inducing ligand-independent homodimerization, which activates pSTAT3 and MYC pathways to enhance chondrocyte proliferation, reduce apoptosis and hypertrophy, and block catabolic effects of IL-6 family cytokines like IL-6 and OSM by preventing heterodimerization. Discovered in Denis Evseenko's lab at the Keck School of Medicine (University of Southern California), it demonstrated disease-modifying effects in rat models of partial meniscectomy (preventing cartilage loss) and osteochondral defects (promoting repair), with plans for clinical trials in osteoarthritis; it is available as a research chemical from suppliers like Axon Medchem and MedChemExpress.[1][2][6][10][13]