Wdr5 is developmentally expressed in osteoblasts and accelerates osteoblast differentiation
in vitro and in vivo. To address whether Wdr5 is essential for osteoblast differentiation,
plasmid-based small interfering RNAs were used to stably suppress endogenous Wdr5
protein levels in MC3T3-E1 cells. Reduction of endogenous Wdr5 levels markedly inhibited
osteoblast differentiation, evidenced by a significant decrease in alkaline phosphatase
activity, Runx-2 and osteocalcin mRNAs, and absence of mineralized matrix formation. Wdr5 …