The Impact Of Offspring’s Neural Development Of High Maternal Serum Estradiol Exposure

Part Ⅰ Intelligence follow-up of offspring with prenatal estrogen exposureObjective:Health of children born with assisted reproductive technology receives more and more attention.Elevated serum estrogen resulted from super-ovulation or Ovarian Hyperstimulation Syndrome(OHSS)has been proved to impose negative effects on offspring,including higher risks of low birth weight and small-for-gestational-age birth,cardiovascular dysfunction.However,Little is known considering its negative impact on offspring’s neurodevelopment.Materials and Methods:109 children from OHSS mothers,200 children conceived with non-OHSS IVF and 148 spontaneously conceived(SC)children were recruited in this study.The Chinese Version of Wechsler Intelligence Scale for Children-Revised(C-WISC)were used to evaluate offspring’s Verbal Intelligence Quotient(VIQ),Performance Intelligence Quotient and Full Intelligence Quotient(FIQ).Results:Offspring from OHSS mothers showed lower score in C-WISC as compared to offspring from non-OHSS IVF offspring or SC offspring.The incidence of low IQ(<80)was significantly higher in OHSS offspring than other two groups.A negative correlation was found between offspring’s VIQ,PIQ and FIQ with maternal serum estrogen level on hCG.Male offspring showed lower IQ than their counterpart in population whose maternal serum estradiol level were over 16000pM on hCG administration day.Conclusion:Offspring of OHSS mothers showed intellectual impairment,which differed between the sexes,with male offspring suffer more than females.Supra-physiological maternal estradiol level is associated with the intellectual impairment.Part Ⅱ Animal Model of prenatal excessive estrodiol exposure and behavior tests.Objective:To study the impact of prenatal excessive exposure on offspring’s neurodevelopment and the underlying mechanismMaterials and Methods:pregnancy mice were given by gacage with estradiol valerate during 5.5 to 11.5 dpc.Birth weight and the development of offsprings were recorded.Behavior tests were conducted to evaluate offspring’s motor development,learning and memory,social ability,depression and anxiety.Results:Animal model were constructed successfully,which was validated with maternal serum estradiol level.Offspring with prenatal excessive estrodiol exposure showed lower birth weight and development delay.In open field test,the motor development was no difference between two groups.Offspring with prenatal high estrodiol exposure displayed less time with new position object in object location task and object in-place task and spent less time in the quadrant of platform in water maze.no difference was showed between two groups in fear conditioning task.In sociability test,offspring from the prenatal high estrogen exposure group spent less time in mouse chamber.Offspring of two groups displayed no difference in elevated plus maze and force swimming test.Conclusion:Prenatal excessive estrodiol impaired offspring’s learning,spatial memory and social ability and had no influence on offspring’s motor development,anxiety and depression.Part Ⅲ The mechanism of high estradiol exposure impairing offspring’s hippocampe neurodevelopmentObjective:Based on animal model,we plan to study the molecular mechanism of prenatal excessive estrogen exposure leading to offspring’s worse performance in behavior tests by affecting offspring’s hippocampe neurodevelopment.Materials and Methods:RNA of hippocampus was isolated for transcriptome microarray.Validation was performed on hippocampus of both fetal and adult mice.Differentiation of human embryonic stem cell was induced in vitro to simulate the influence of high concentration of estradiol imposed on embryo development.Results:Genes expression profile of hippocampus was changed by prenatal high estradiol exposure in transcriptome microarray.IPA showed that differentially expressed genes mostly enrich in behavior and neurodevelopment.The downstream analysis of microarray data revealed that neural stem cell proliferation was probably affected.Neural stem cell was isolated successfully from 18.5dpc fetal mice.The size of neurosphere,BrdU immunofluorescence staining and differentiation showed that profileration of neural stem cell and the ability of differentiate into neuron were impaired in male offspring from exposure group.Moreover,male adult mice from exposure group showed impaired hippocampus neurogenesis by doublecortin(DCX)immunofluorescence staining.In human embryonic stem cell,high concentration of estrodiol decreased the number of neural stem cell derived from embryonic stem cell,which was not observed in low concentration of estrogen.Conclusion:Prenatal excessive estrogen altered gene transcription in offspring’s hippocampus,lead to abnormal proliferation and differentiation of neural stem cell in hippocampus,subsequently impaired neurogenesis of hippocampus in adult period.On the other hand,high concentration of estrogen disturbed the differentiation process from human embryonic stem cell to human neural stem cell.