| ObjectiveEpilepsy is a sudden abnormal discharge of brain neurons,which leads to a chronic disease of brain dysfunction.Since 1960,the VPA has acted as a treatment of epilepsy.However,from the clinical evidence,it suggests that children with prenatal exposure to VPA will suffer from orofaeial clefts,congenital heart disease,NTDs,limb deficiencies,genitourinary defects and craniosynostosis.Children with prenatal VPA exposure also shows obvious social communication disorders and repeat stereotypic behavior,some of which are eventually diagnosed as autism.Based on chick embryo as experimental object,this paper studies the effects of VPA exposure during embryonic period on the offspring.And exploring related mechanism of nerve injury induced by VPA exposure during the embryonic period by means of the detection of gene and protein level.Methods Using Isa brown chicks'embryos as experimental objects,and everyday the embryos are exposed to different concentration of VPA during ED 8-14.Recording the incubation duration;Using the the surface righting test to detect the physical condition of hatched chicks;Using one-trail passive avoidance test to detect learning and memory abilities of chicks;Using of SSS test and isolated behavior test to detect the autistic behaviors of chicks;Using qRT-PCR to detect the gene expression level of BDNF,TRKB,p75NTR,NMDAR,SYN,NCAM,GAD65,GAD67,GABA_AR?2,FOXP2and CNTNAP2;Using Western blotting to detect the protein level of FMRP,CASPR2,pro-BDNF and BDNF in hippocampus.Results(1)The incubation duration of chick,which is exposed to VPA during the embryonic period,are longer than the control.And the time needed for surface righting of chick,which is exposed to 5 mg/mL VPA during the embryonic period,have significant differences with the control;(2)The ability of long-term memory chick which is exposed to 3 mg/mL VPA during the embryonic period is weaker than the control,and it's time of G-move is longer than the control;(3)The abilities of short-term,intermedia-term and long-term memory of chicks which is exposed to 4mg/m L VPA is weaker than the control,and the abilities of intermedia-term and long-term memory of chicks which is exposed to 5 mg/mL VPA is weaker than the control;(4)The chick,which is exposed to 4 mg/m L or 5 mg/mL VPA during the embryonic period,shows obvious autistic behavior,including the increased time needed for aggregation,reduced sense of belonging,reduced D-call and decreased time of G-move;(5)In the brain of chick which is exposed to 3 mg/m L VPA during the embryonic period,the gene expression level of GABA_AR?2 is up-regulated,and the gene expression level of CNTNAP2 is down-regulated;(6)In the brain of chick which is exposed to 4 mg/mL VPA during the embryonic period,the gene expression level of BDNF,p75NTR and GABA_AR?2 is up-regulated,and the gene expression level of SYN,FOXP2 and CNTNAP2 is down-regulated.In addition,the protein level of FMRP and CASPR2 which is encoded by CNTNAP2 is down-regulated;(7)In the brain of chick which is exposed to 5 mg/m L VPA during the embryonic period,the gene expression level of BDNF and GABA_AR?2 is up-regulated,and the gene expression level of TRKB,NR1,SYN,NCAM,FOXP2 and CNTNAP2 is down-regulated.In addition,the protein level of pro-BDNF and BDNF is up-regulated,and the protein level of CASPR2which is encoded by CNTNAP2 is down-regulated;Conclusion We believe that 4 mg/mL and 5 mg/mL VPA exposure during the embryonicperiodhaveobviousimpactsonphysicaldevelopmentand neurodevelopmental of the offspring.4 mg/mL and 5 mg/mL VPA may mainly inhibit the TRKB signaling pathways,and enhance p75NTR signaling pathway,which could trigger the cell apoptosis in the early neurodevelopmental,ultimately resulting to the damage of neural development.While 3 mg/mL VPA bring less impact on the physical development and neural development of offspring.In addition,VPA exposure during embryonic period leads to language impairment,which maybe is related with the destruction of FOXP2-CNTNAP2 signaling pathway. |
PDF Full Text Request