A Chondrogenic Molecule that Repairs Cartilage by Transcriptional Regulation of CBF-beta

Osteoarthritis (OA) is a degenerative joint disease that involves destruction of articular cartilage and eventually leads to disability. Mesenchymal stem cells (MSCs) reside in healthy and diseased cartilage, and through their chondrogenic potential may provide a strategy for cartilage repair. To this end, we performed an image-based, high throughput screen and identified the small molecule, kartogenin, that promotes selective MSC differentiation into chondrocytes (EC50=100nM), shows chondroprotective effects in vitro, and is efficacious in two OA animal models. Kartogenin binds filamin A and induces chondrogenesis by regulating the CBFbeta-RUNX1 transcriptional program. This work provides new insights into the control of chondrogenesis that may ultimately lead to an effective stem-cell based therapy for osteoarthritis. one compound, three doses, two time points, a vehicle control