Expression of bone morphogenetic protein7 in developing rat tooth

Abstract

Background: Bone morphogenetic proteins (BMPs) are secretory signal molecules
which have a variety of regulatory functions during morphogenesis and cell
differentiation. Teeth are typical examples of vertebrate organs in which
development is controlled by sequential and reciprocal signaling between the
epithelium and mesenchyme. In addition, tooth development is characterized by
formation of mineralized tissues, dentin and cementum as well as epithelially
derived enamel. BMp 7 plays a role with other signaling molecules in tooth
development.
Aim of the study: To perform immune-histochemical analysis of the expression of
BMP7starting from initiation of tooth development to completion of crown
morphogenesis when dentine and enamel matrices are being deposited in rat
incisor tooth Materials and Methods: Sixteen rat embryos were obtained from
pregnant rats in gestation periods 16th,17th,18th,20th intrauterine life and eight
neonatal one day and 3 day old rat were included in this study . Each period
involved 4 embryos or neonatal rats. Premaxilla ( containing incisor teeth) was
dissected and fixed in 10% buffered formalin and embedded in paraffin. Block
sections (4 μm thickness) for Immunohistochemical localization of BMP7.
Results: Positive expression of BMP7 was recorded in ectoderm derived cells only, in
developing tooth germ include oral epithelia, dental lamina and inner enamel
epithelia in gestation period 16th,17thand 18thintrauterin life of rat embryo. Then
the expression was illustrated in specialized cell of dental papilla the odontoblast
and the developing dentin matrix .Ameloblast cell expressed too BMP7 in its
formative and maturative stages.
Conclusion: Bone morphogenetic protein 7 may play key roles in mediating
induction, differentiation events during tooth development.