TCDD Affect The Development Of Palate Through The Peripheral Immune System And Placenta Directly Or Indirectly

ObjectiveChemical teratogen(TCDD)can cause the palate cleft,and non-specific immune stimulation decreased the rate of palate cleft.The related research has found that maternal immune cytokines can cross placenta to alleviate the toxicant-mediated effect in fetal development.However,the normal placenta is critical for the development of the fetus.This work aims to research the relation between palate cleft and peripheral immune function,the pathological damage of placenta.Materials and MethodsC57BL/6J mice were administered TCDD by gavages at 20 ?g/kg from gestational days 10(GD10).Treated mice were sacrificed for embryo and placenta collection and weight at gestational days(GD18).Hematoxylin and eosin staining was observed the effect of TCDD on the histopathology of placenta,was used to examine the effect of TCDD on the proliferation of placenta and labyrinth vascularization;Flow cytometric method was to investigate the effects of TCDD on the peripheral blood Thl/Th2 cell;Elisa was used to evaluate the concentration of IL-4 and IFN-?..Results1)At GD18.treatment with TCDD significantly reduced the weight of placenta(P<0.05)and the ratio of placental weight to body weight compared to control group,however,the difference of the embryo weight has no statistical significance(P>0.05).2)At GD18,treatment with TCDD significantly decreased total area of placenta(P<0.05),area of spongiotrophoblast and labyrinth vascularization of placentas.3)At GD18,treatment with TCDD significantly decreases the ratio of TH2/TH1 cells and the number of the Th2(P<0.05),while the difference of the Thl has no statistical significance(P>0.05).4)At GD18,treatment with TCDD decreases the concentration of IFN-y and IL-4 in the blood(P<0.05),however the IL-4 is more obvious.Conclusion1)The exposure to TCDD may inhabit the development of placenta during the pregnancy2)TCDD disrupts the formation of labyrinth vascularization and spongiotrophoblast during the pregnancy.3)TCDD induces Thl polarization of peripheral blood immune cell and changes the cytokine IFN-y and IL-4.4)All these may affect the development of palate cleft directly or indirectly.