LRP5

Low-density lipoprotein receptor-related protein 5, commonly known as LRP5, is a transmembrane protein encoded by the LRP5 gene in humans. It is a member of the low-density lipoprotein receptor (LDLR) superfamily and plays a crucial role in various biological processes, particularly those related to bone metabolism and Wnt signaling. LRP5 acts as a co-receptor, meaning it binds to signaling molecules and helps them to activate their respective downstream pathways. Its primary function is in the Wnt/beta-catenin signaling pathway, where it works in conjunction with Frizzled receptors. This pathway is essential for embryonic development, cell growth, differentiation, and tissue homeostasis.

In bone, LRP5 is vital for osteoblast differentiation and bone formation. Mutations in the LRP5 gene can lead to a spectrum of skeletal disorders. Loss-of-function mutations are often associated with osteogenesis imperfecta (OI), a group of genetic disorders characterized by brittle bones and increased fracture susceptibility. Conversely, gain-of-function mutations in LRP5 can result in high bone mass (HBM) phenotypes, where individuals have unusually dense and strong bones, making them resistant to fractures. Research into LRP5 has provided significant insights into the regulation of bone density and has opened avenues for therapeutic strategies targeting bone diseases like osteoporosis.