Bone anabolic agents promoting bone formation and rebuilding damaged bones would ideally overcome the limitations of anti-resorptive therapy, the current standard prescription for osteoporosis. However, the currently prescribed parathyroid hormone (PTH)-based anabolic drugs present limitations and adverse effects including osteosarcoma during long-term use. Also, the antibody-based anabolic drugs that are currently being developed present the potential limits in clinical application typical of macromolecule drugs. We previously identified that CXXC5 is a negative feedback regulator of the Wnt/β-catenin pathway via its interaction with Dishevelled (Dvl) and suggested the Dvl-CXXC5 interaction as a potential target for anabolic therapy of osteoporosis. Here, we screened small-molecule inhibitors of the Dvl-CXXC5 interaction via a newly established invitro assay system. The screened compounds were found to activate the Wnt/β-catenin pathway and enhance osteoblast differentiation in primary osteoblasts. The bone anabolic effects of the compounds were shown using exvivo-cultured calvaria. Nuclear magnetic resonance (NMR) titration analysis confirmed interaction between Dvl PDZ domain and KY-02061, a representative of the screened compounds. Oral administration of KY-02327, one of 55 newly synthesized KY-02061 analogs, successfully rescued bone loss in the ovariectomized (OVX) mouse model. In conclusion, small-molecule inhibitors of the Dvl-CXXC5 interaction that block negative feedback regulation of Wnt/β-catenin signaling are potential candidates for the development of bone anabolic anti-osteoporosis drugs.
Bibliographical noteFunding Information:
We thank Bum Tae Kim and Sung-Youn Chang for discussion on the design and the synthesis of molecules. This work was supported by grants from the Ministry of Future Creation and Science (MFCS) of Korea through National Research Foundation (NRF); Translational Research Center for Protein Function Control (2009-0083522); and Mid-career Researcher Program (2015R1A2A1A05001873). This work is also supported by the Ministry of Knowledge Economy through Korea Research Institute of Chemical Technology (SI-0905, SI-1005, SI-1105, SI-1205, SI-1304).
All Science Journal Classification (ASJC) codes
- Molecular Medicine