For healthy eyes and bones : got Lrp?

The Wnt family of secreted proteins controls several crucial developmental processes, some of which are apparently mediated by Wnt coreceptors from the LDL receptor-related protein (Lrp) family. Now, on page 303, Kato et al. report that the targeted disruption of Lrp5 in mice causes a phenotype virtually identical to that seen in humans with osteoporosis-pseudoglioma syndrome. In addition to identifying a long-sought genetic component for bone mass determination, the work identifies Lrp5 as a critical component for controlling both osteogenesis and eye vascularization during late stages of development.Mice lacking functional Lrp5 exhibit lower rates of bone formation than wild-type mice, and fail to achieve normal bone mass early in life. This happens despite normal expression of Cbfa1, a protein thought to be the principal controller of osteogenesis, suggesting that Lrp5 functions in an...