Abstract: Objective The glucocorticoid dexamethasone (DEX) can induce palatal cleft; however, the mechanism involved remains unclear. E-cadherin is an important cell adhesion molecule, and it can significantly affect cell fate and embryonic development. Recent studies have indicated that E-cadherin expression in palatal epithelial cells is suppressed in normal palate fusion. This study aimed to determine whether the change in E-cadherin expression is related to the incidence of cleft palate in DEX-induced mice. Methods Mice were divided into the experimental group and the control group. Pregnant mice were injected with DEX on E10.0–E12.0, whereas mice in the control group were injected with normal saline. Hematoxylin and eosin (HE) staining, immunohistochemistry, and real-time quantitative polymerase chain reaction were employed to evaluate the effect of DEX on fetal mouse palatal processes, particularly the changes in E-cadherin and β-catenin expression levels in the phases of the experimental and control groups. Results Data indicated that the incidence of cleft palate in the DEX group was 43.59% (17/39), whereas that in the control group was only 3.03% (1/33). The results of HE staining showed that the obviously shortened palatal processes could not contact and fuse with one another in the DEX-treated mice model compared with those in the control group. The ectopic expression of E-cadherin in embryonic palatal mesenchymal cells was also analyzed. The expression levels of E-cadherin and β-catenin in the experimental group were higher than those in the control group. Conclusion These findings indicated that DEX could induce E-cadherin gene upregulation and ectopic expression, as well as high β-catenin expression, thereby inhibiting the growth of mesenchyme cells and cleft palate.

Key words: dexamethasone, E-cadherin, β-catenin, cleft palate