Study On The Correlation Between Maternal Chemicals Exposure During Pregnancy And Gut Microbiota Of Mice Model With Autism Spectrum Disorder In Offspring

Objective: Use four kinds of drugs(chemicals)that are easily exposed during pregnancy,namely lipopolysaccharide(LPS),valproic acid(VPA),Polyinosine:poly(I:C)and triclosan(TCS),respectively intervene in ICR mice during pregnancy to construct the offspring autism spectrum disorder(ASD)mice model.On this basis,further study the composition of gut microbiota and the changes of gene expression in the prefrontal cortex of ASD mice model.It aims to provide data support for the study of the etiology and molecular mechanism of ASD.Methods: The ICR mice were mated at night and females were examined every morning for the presence of vaginal plugs.If vaginal plugs were observed,they were noted as gestation day 0.5(GD0.5).Pregnant mice were administered with a single dose of TCS(50mg/kg)every day via oral gavage since GD7.5 until postnatal day 21 of the offspring,while the control group(T＿Con group)received corn oil only.In addition,on GD12.5,the pregnant mice of each model group(LPS group,Poly(I:C)group or VPA group)was respectively received a single dose of LPS(100μg/kg),Poly(I:C)(20mg/kg)or VPA(500mg/kg)by intraperitoneal injection,while their Control mice were treated with saline.At the sixth week after the birth of offspring,the fresh feces of each mouse was collected for sequencing and analysis of gut microbiota.At 6-8 weeks,behavioral tests were performed on the mice through the open field test and the three-chamber sociability test.According to the behavioral characteristics,the offspring ASD model mice(male)with typical autism-like behaviors were screened.On this basis,two mice from each group were randomly selected for brain prefrontal cortex RNA-seq,to analyze the gene expression of the brain of mice in each group.Results: In the open field test,compared with the corresponding control group,the self-grooming time and frequency of mice in the LPS group,Poly(I:C)group,VPA group and TCS group were significantly increased,but the increase in the self-grooming time of the LPS group mice was not statistically significant difference(P >0.05).In the three-chamber sociability test,compared with the corresponding control group,the social time and frequency of the mice in the LPS group,Poly(I:C)group,VPA group and TCS group were significantly reduced,but there was no significant difference in the reduction of the social frequency of the mice in the Poly(I:C)group(P > 0.05).The results of the intestinal microbiota showed that among the four different ASD models,a total of 5 phylum,79 genus and 63 species were observed with significant differences.At the same time,some gut microbiota closely related to the occurrence and development of ASD were analyzed,including Mailhella and Roseburia,as well as Butyricimonas virosa,Streptococcus danieliae,Akkermansia muciniphila,Kineothrix alysoides,etc..The RNA-seq results showed that a total of 241 gene expressions were detected to have significant changes in four different ASD models,including four significantly down-regulated genes related to the nervous system(ZBTB16,MERTK,SMIM3 and GBX1)and one significant up-regulated consensus gene(CSNK2A3).Among them,CSNK2A3 may participate in the occurrence and development of ASD by inhibiting the proliferation of nerve cells.Conclusion: Exposure to drugs(chemicals)during pregnancy can induce ASD-related behavioral abnormalities in offspring mice.Exposure to four different drugs during pregnancy can have varying degrees of influence on the composition of the gut microbiota and the gene expression of the prefrontal cortex of the brain of the offspring ASD mice model.Although there are differences in the intestinal microbiota and genes between mice and humans,the results of this study can provide a reference for the study of the etiology and pathogenic mechanism of ASD.