Expression Of The Eda In The Tooth Germ Of Human Dental Papilla Mesenchymal Cells

Hypohidrotic Ectodermal Dysplasia ( HED ) is an inheritantdiseasecharacterized with hypotrichosis, hypohidrosis, anadontia or hypodontia.Three kinds of inheritant patterns exist: X linked (XLHED), autosomal dominat(ADHED ) and autosomal recessive (ARHED) . Among them, XLHED is themost common one.The pathogenic gene of XLHED is called EDA gene, cloned in 1996 by Kere J. It belongs to the TNF ligand family. Recent researches show that EDA gene was expressed in the oral epithelial and outer enamel epithelial of murine tooth germ in the cap stage. Mutation of EDA gene would cause the abnormal development of enamel knot. So, it is supposed that EDA gene play a role in the morphogenetic development of murine teeth.Nowadays, no studies about the role of this gene in human tooth development have been reported.Antibody of EDA protein was made, and several technologies such as immunohistochemistry, immunoflurescence were used to investigate the expression of ED A protein in the tooth germ of mice and human. The expression of EDA protein in the human dental papilla mesenchymal cells cultured in vitro and the common biological features as well as the expression of EGFR in the human dental papilla mesenchymal cells transfected with EDA gene were also detected.We can not detect the expression of EDA protein in the tooth germs of both mice and human in all kinds of stages. Strong expression can be detected in the maxillary glands, cartilage and epiderm, however. There was weak expression of EDA protein in cultured human dental papilla mesenchymal cells.We also found that over expression of EDA protein would inhibit the growth and AKP activity of human dental papilla mesenchymal cells. EGFR expression was increased in human dental papilla mesenchymal cells transfectedwith EDA gene.