Bone morphogenetic proteins (BMPs) and tooth development

Abstract

Bone Morphogenetic Proteins (BMPs) exhibit multiple functions during development. They are assumed to play signaling roles in the mediation of epithelio-mesenchymal interactions during tooth development and repair. This review aims to survey the hitherto data on BMPs during tooth development with an attempt to stress a possible functional relationship between epithelial BMPs expression and regressive processes representing integral part of normal odontogenesis. During tooth development, BMPs gene transcription appears to be involved in early condensation and further differentiation of the dental mesenchyme and of its derivatives. The expression of BMPs transcripts in the dental epithelium, however, is specifically restricted both in space and time during prenatal development. In mouse, these sites of BMP-2, BMP-4 and BMP-7 transcripts mostly fit with the areas, where apoptosis has been reported during reduction or even elimination of specific dental epithelial cell populations: i. rudimental tooth primordia in the prospective mouse diastema, ii. the enamel knot, iii. ameloblasts, iv. the residual dental lamina (gubernaculum of the enamel organ). These data strongly suggest involvement of the BMP-4 in upregulation of apoptosis also during odontogenesis. A possible implication of other BMPs and their precise role in regressive processes should be investigated.