Overexpression of transforming growth factor-beta1 in teeth results in detachment of ameloblasts and enamel defects.

[dentin dysplasia]

Transforming growth factor -beta 1 (TGF-beta 1 ) is a key regulator of many cellular processes , including cell adhesion , the immune response and synthesis of extracellular matrix proteins . In the present study , we report the characterization of enamel defects in a transgenic mouse model overexpressing TGF-beta 1 in odontoblasts and ameloblasts , its expression being driven by the promoter sequences of the dentin sialophosphoprotein gene . As reported earlier , these mice develop distinct dentin defects similar to those seen in human dentin dysplasia and dentinogenesis imperfecta . A further detailed examination of enamel in these mice revealed that from the early secretory stage , ameloblasts began to detach from dentin to form cyst-like structures . A soft X-ray analysis revealed that this cyst-like structure had a disorganized and partially mineralized matrix with an abnormal mineralization pattern and a globular appearance . In the molars , the enamel was not only pitted and hypoplastic , but enamel rods were completely lost . Thus , altered TGF-beta 1 expression in the tooth seems to trigger detachment of ameloblasts and abnormal secretion and deposition of minerals in the cyst-like structures adjoining the dentin . We speculate that the altered expression of TGF-beta 1 in teeth impacts the adhesion process of ameloblasts to dentin .

Diseases
Validation

Diseases presenting "abnormal secretion" symptom

dentin dysplasia

You can validate or delete this automatically detected symptom