Lgr4 in ocular development and glaucoma

The leucine-rich repeat-containing g protein-coupled receptor 4 (lgr4,also called gpr48) plays a key role in multiple developmental processes,and mice lacking lgr4 display anterior segment dysgenesis leading to early-onset glaucomatous retinal ganglion cell loss as well as defective eyelid formation. this paper will review lgr4 signaling and its regulation of the axenfeld-rieger syndrome gene pitx2,a crucial developmental transcription factor. in addition,wnt signaling plays an important role in eye development,with norrin functioning to activate the wnt receptor frizzled 4 required for proper retinal vascularization. recent discoveries identifying lgr4 as a receptor for norrin highlight the potential for lgr4 function in retinal vascularization. finally,several unanswered questions impeding a full understanding of lgr4 in glaucoma are considered as avenues for further research. © 2013 stefan siwko et al.