Volume 52 (1): 103-112, 2004 Copyright ©The Histochemical Society, Inc. Immunolocalization of BMP-2/-4, FGF-4, and WNT10b in the Developing Mouse First Lower Molar
INSERM U595, Institut de Biologie Médicale, Faculté de Médecine, Strasbourg, France Correspondence to: A. Nadiri, INSERM U595, Institut de Biologie Médicale, Faculté de Médecine, 11, rue Humann, 67085 Strasbourg cedex, France. E-mail: Amal.Nadiri{at}odonto-ulp.u-strasbg.fr Intercellular signaling controls all steps of odontogenesis. The purpose of this work was to immunolocalize in the developing mouse molar four molecules that play major roles during odontogenesis: BMP-2, -4, FGF-4, and WNT10b. BMP-2 and BMP-4 were detected in the epithelium and mesenchyme at the bud stage. Staining for BMP-2 markedly increased at the cap stage. The relative amount of BMP-4 strongly increased from E14 to E15. At E15, BMP-4 was detected in the internal part of the enamel knot where apoptosis was intense. In contrast to TGFß1, BMP-2 and -4 did not show accumulation at the epithelialmesenchymal junction where the odontoblast started differentiation. When odontoblasts became functional, BMP-2 and BMP-4 were detected at the apical and basal poles of preameloblasts. BMP-2, which induces ameloblast differentiation in vitro, may also be involved physiologically. The decrease in FGF-4 from E14 to E15 supports a possible role for the growth factor in the control of mesenchymal cell proliferation. The relative amount of FGF-4 was maximal at E17. The subsequent decrease at E19 showed correlation with the withdrawal of odontoblasts and ameloblasts from the cell cycle. WNT10b might also stimulate cell proliferation. At E14-15, WNT10b was present in the mesenchyme and epithelium except for the enamel knot, where the mitotic activity was very low. At E19 there was a decreasing gradient of staining from the cervical loop where cells divide to the tip of the cusp in the inner dental epithelium where cells become postmitotic. The target cells for FGF-4 and WNT10b appeared different. (J Histochem Cytochem 52:103112, 2004)
Key Words: tooth development immunohistochemistry epithelialmesenchymal interactions enamel knot BMP FGF WNT
This article has been cited by other articles:
|
|
||||||||||||||||||||||||||||||||||||