Expression Of Gamma-aminobutyric Acid Type A Receptor Beta3 Subunit In Murine Cleft Palate Induced By 2,3,7,8-tetrachlorodibenzo-p-dioxin

Objective: To investigate the expression of Gamma-aminobutyric acid type A receptor beta3 subunit(GABRB3)in C57BL/6J mice cleft palate induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD).To explore the relationship between GABRB3 and congenital cleft palate induced by TCDD.Methods: Sixty pregnant C57BL/6J mice were divided into two groups according to the random number table method,30 mice in each group.One group was given 28 ?g/kg TCDD by gavage(experimental group)and the other group was given 5.6 ml/kg corn oil by gavage(control group)only once from gestation day 10.5.Embryos were removed by cesarean section from pregnant mice during the palatal formation stage(GD13.5-17.5).The morphological observation and histological observation were used in process.The relative mRNA and protein expression of GABRB3 was measured by quantitative real-time PCR and western blot in different palatal formation stage.Immunohistochemistry staining and Immunofluorescence staining were used to detect the expression and localization of GABRB3 protein.Results: The incidence of cleft palate was 100% in experimental group and no cleft palate occurred in the control group;Elevation of palatine processes in experimental group was clearly delayed for a day compared with the control group.At GD14.5?GD15.5?GD16.5?GD17.5,the relative expression level of mRNA and protein of GABRB3 in the experiment group were significantly lower than the control group(P<0.05).In the control group,the relative expression level of mRNA and protein in GD14.5?GD15.5?GD16.5?GD17.5 were significantly higher than GD13.5.In the experimental group(P<0.05),the relative expression level of mRNA and protein in GD15.5 and GD16.5 were significantly higher than GD13.5?GD14.5(P<0.05).The result of Immunohistochemistry and immunofluorescence staining showed that GABRB3 mainly expressed on mesenchymal cells and medial edge seam.Conclusion: The model established of cleft palate in C57BL/6J mice was successfully induced by TCDD,which confirmed the high efficiency and stability of TCDD in inducing cleft palate.TCDD delayed palatal shelf elevation and eventually led to cleft palate may be associated with the decrease of GABRB3.GABRB3 may play an important role in the elevation and fusion phases of the palate development.