The Role On Histone H4 Acetylation And Gene TGF-beta Receptors MRNA During Cleftpalates Induced By TCDD In Mice

Part? The role On histone H4 acetylation during cleft palates induced by TCDD in miceObjective: To explore histone H4 acetylation(Ac-H4)expression variation during the cleft palates induced by 2,3,7,8-tetrachlorodibenzo-pdioxin(TCDD)in mice,and their relationship.Methods: Forty-eight pregnant C57BL/6J mice were completely randomly divided into experimental and corn oil control groups.At GD10.5,the mice in the experimental group were subjected to once gastric perfusion with 20ug/kg of TCDD,and those in the corn oil control group received equivalent corn oil.The pregnant mice were sacrificed on GD13.5,GD14.5 and GD15.5,collecting the heads to be sliced in coronal plane.Immunohistochemical staining was used to observe the expression of histone H4 acetylation in the palatal process.The relative expression of histone H4 acetylation in fetal mice palatal tissue was detected by Western Blotting.IBM SPSS24.0 software was applied for statistical analysis.One-way ANOVA was used for comparison of the relative expression,and the Bonferroni?s test was carried out for homogeneity of variance,and and the error of variance was corrected by the corrected t test.The P<0.05 was considered statistically significant.Results: The Histone H4 acetylation was mainly expressed in palatal epithelial cells and slightly expressed in mesenchymal cells.The expression level of histone H4 acetylation was 0.6002�0.2530,0.9180�0.0941 and 0.8966�0.0908 in corn oil control group on GD13.5,GD14.5 and GD15.5;while 1.0229�0.2779,1.6095�0.2651 and 1.2758�0.1251 in TCDD experiment group.There were statistically significant differences between the control group and TCDD group(P<0.05).Conclusions: The histone H4 acetylation was involved in the cleft palate induced by TCDD in C57BL/6J mice.The significant up-expression of histone H4 acetylation at GD13.5~GD15.5 may be one of the epigenetic mechanisms which causes the palate in fetal mice induced by maternal exposure to TCDD.Part? Experimental research of gene T?Rs during cleft palates induced by TCDD in miceObjective:To investigate the correlation between T?R-?,T?R-?,T?R-? gene and TCDD-induced mouse embryonic palatal development disorder.Methods:24 pregnant C57BL/6J mice were randomly divided into the experimental group and the corn oil control group.Each group was divided into three subgroups according to the pregnancy day,with 4 pregnant mice in each group.On the gestation day 10.5(GD10.5),the mice in the experimental group were subjected to once gastric perfusion with 20ug/kg of TCDD,while the those in the control group received the equivalent corn oil.The pregnant mice were sacrificed on GD13.5~GD15.5,collecting the fetal palates.The T?R-?,T?R-? and T?R-? m RNA of fetal palates were analysed by Q-PCR.Results:The mice in the TCDD group suffered from the palate malformation,while the mice of control group were normal.The consequence of Q-PCR analysis revealed that the relative expression level of TGF?R-? was 2.06�0.21,1.38�0.12 and 0.78�0.17 in the corn oil control group on GD13.5,GD14.5 and GD15.5,while 0.98�0.26,0.75�0.14 and 1.22�0.05 in the TCDD experiment group;The relative expression level of T?R-? was 1.84�0.08,1.14�0.09 and 0.81�0.13,in the control group on GD13.5,GD14.5 and GD15.5,then 0.91�0.22,0.96�0.06 and 1.30�0.13 in TCDD experiment group;The expression level of T?R-? was 1.86�0.10,1.11�0.11 and 0.67�0.15 in the control group on GD13.5,GD14.5 and GD15.5,yet 0.85�0.05?0.93�0.09?1.17�0.16 in the TCDD group.The relative expression level of T?R-?,T?R-? and T?R-? was lower in the TCDD group than that in the control group at GD13.5 and GD14.5(P<0.05),while higher at GD15.5(P<0.05).Conclusions: The TCDD-induced fetal palate showed low expression level of T?R-?,T?R-? and T?R-? m RNA comparing the control group at GD13.5 and GD14.5,but up-expression at GD15.5.Thus the low expression of T?R-?,T?R-? and T?R-? m RNA was likely to be involved in the process of fetal mice palate malformation.