Mechanisms And In Tervention Of Tributyltin Exposure On Female Reproductive System

In recent years,the incidence of female reproductive diseases has been on the rise,posing a major threat to human health and social development.With the development of industrialization,researches have showed both genetic and environmental factors contribute to the development of female reproductive diseases.Environmental endocrine disruptors(EDCs)are widespread in environment,which interfere with metabolism of the organism and thus impact human health.In this study,tributyltin(TBT),a typical EDC,was selected.We investigate the effects and mechanisms of environment-relevant levels of TBT(100 ng/kg)on female reproductive system in rats.These help us to explore more safe and healthy prevention and treatment of female reproductive diseases.The main results are as follows:1.In this study,neonatal exposure to environment-relevant levels of TBT leads to polycystic ovarian syndrome(PCOS)in rats,which is ameliorated by resveratrol(RSV)treatment.TBT exposure influenced cell projection assembly.A series of experiments including transcriptome analysis,quantitative real-time polymerase chain reaction(RT-PCR),western blot and phalloidin staining showed that excessive calcium/calmodulin-dependent protein kinase Ⅱβ(CaMKⅡβ)caused by TBT exposure bond to monomeric actin and inhibited transzonal projection(TZP)assembly in antral follicles.As the communication bridge between oocytes and granulosa cells,injury of TZP influences folliculogenesis and finally causes PCOS.We also observed TZP disruption and CAMK2B upregulation in human PCOS samples using Gene Expression Omnibus(GEO)database analysis and RT-PCR,offering a new perspective on the pathogenic mechanism of PCOS.Moreover,we demonstrated that RSV potently ameliorated ovarian failure and estrus cycle disorder through TZP recovery via increased cytoplasmic calcium levels and excessive phosphorylation of CaMKⅡβ.2.Adult rats from the control group and the TBT-exposed group mated with normal males to explore the genetic effect of PCOS caused by EDCs.The animal experiment showed that TBT-induced PCOS transmitted to F1(intergenerational),F2 and F3(transgenerational)offspring,TZP injury was observed in antral follicles of TBT-exposed F3 female rats.A combined methylation and transcriptome analysis of unexposed F2 female rats ovaries showed differentially expressed genes(DEGs)and differentially methylated region(DMR)-associated genes were significantly enriched in the biological process of cell projection organization.RT-PCR was used to verify the transcription level of DEGs in ovaries,DMR methylation levels were also verified in rat ovaries.Increased DNA methylation levels of Adcy9,a key gene for TZP assembly,were detected in the ovaries of three generations of TBT exposed female offspring.3.TBT exposure resulted in uterine dysplasia and endometritis,which can be effectively improved by RSV intervention.16s rDNA sequen cing analysis of vaginal microbe showed a significant increase of Escherichia-Shigella and microbiome disorder in TBT exposed rats.The composition of vaginal microbiota was basically consistent with that of the control group after RSV intervention.RSV can effectively prevent and treat endometritis due to its antibacterial and anti-inflammatory properties.Disruption of the microbiome homeostasis in reproductive tract might mediate the transmission of endometritis to the next generation.The present research demonstrates that environmental endocrine disruptor TBT causes female reproductive diseases which can be passed through generations.This study revealed the mechanism of pathogenesis and transgenerational inheritance of female reproductive diseases,demonstrated the effectiveness of potential natural medicine on these toxic effects.This study provided a new insight for understanding the mechanism of endocrine disruptors induced female reproductive diseases,which is of great scientific significance and social value.