IADR Abstract Archives
Wnt Signalling in the Apical Papilla is Essential for Tooth Root Development
Objectives: Wnt signalling has been shown to play an essential role during different stages of dental organogenesis. Although disturbances in Wnt signalling have been shown to adversely affect odontogenesis, little is known about its role specifically in root development. The objective of this study is to investigate the role of the Wnt signalling pathway in the proliferation and differentiation of odontogenic stem/precursor cells of the developing root. For this, we have targeted different components of the pathway including the source of Wnts, their responding cells as well as the downstream targets influencing radicular hard tissue formation.
Methods: To localize Wnt activity during different stages of radicular development, we used Axin2LacZ reporter mice. We take advantage of transgenic Wntlessfl/fl and Sox9fl/fl mice to conditionally knock down production in apical stem cells by placing cre under the Gli1 specific promoter. A candidate approach was employed to identify downstream targets through immunofluorescence and in-situ hybridisation. Morphometric analysis was carried out through histology and microCT reconstructions of the involved teeth.
Results: Active Wnt signalling was observed at the advancing front of the developing root. Coincidently, this region is known to harbour the stem/progenitor cells that are specified to form radicular tissues. Targeted cessation of Wnt secretion in specific cell populations resulted in root deformity with short roots and wide apices.
Conclusions: We demonstrate the vital role of Wnts in radicular hard tissue formation. A clearer understanding of the molecular mechanisms of root development will help us decipher the etiopathogenesis of developmental anomalies affecting roots and perhaps, develop targeted biological solutions for truncated root development.
Methods: To localize Wnt activity during different stages of radicular development, we used Axin2LacZ reporter mice. We take advantage of transgenic Wntlessfl/fl and Sox9fl/fl mice to conditionally knock down production in apical stem cells by placing cre under the Gli1 specific promoter. A candidate approach was employed to identify downstream targets through immunofluorescence and in-situ hybridisation. Morphometric analysis was carried out through histology and microCT reconstructions of the involved teeth.
Results: Active Wnt signalling was observed at the advancing front of the developing root. Coincidently, this region is known to harbour the stem/progenitor cells that are specified to form radicular tissues. Targeted cessation of Wnt secretion in specific cell populations resulted in root deformity with short roots and wide apices.
Conclusions: We demonstrate the vital role of Wnts in radicular hard tissue formation. A clearer understanding of the molecular mechanisms of root development will help us decipher the etiopathogenesis of developmental anomalies affecting roots and perhaps, develop targeted biological solutions for truncated root development.