An Experimental Study On The Effect Of LPS On Oocyte And Embryonic Development Potential In Vitro Fertilization

Objective: This project intends to study the effects of LPS on oocyte maturation and its in vitro fertilization embryo development potential and its related mechanisms.By establishing an animal model of inflammatory response induced by LPS in mice,the effect of inflammatory reaction before ovulation on the development of oocytes and in vitro fertilization embryos was investigated.Methods: Twenty adult female SPF ICR mice were randomly divided into 2 groups,10 in each group,and 10 adult SPF ICR male rats.Control group: intraperitoneal injection of normal saline 0.15 ml each for 3 days during ovulation stimulation.Experimental group: LPS group: Intraperitoneal injection of LPS 0.15 ml each for 3 days at the time of ovulation induction(LPS concentration of 100ug/kg,pre-experimental results show that the stimulation dose is not lethal and can cause inflammatory reactions in mice,the increase of inflammatory index was the main criterion for judgment);Both groups of mice were given HCG,PMSG to ovulate,oviparously to take eggs,and were subjected to in vitro fertilization and cultivate through assisted reproduction techniques to observe the number of oocytes,the two-cell rate,blastocyst formation obtained after in vitro fertilization and determine the expression of genes OCT-4 and SOX-2 in blastocysts to reflect the effects of LPS on oocyte maturation and in vitro fertilization embryo development.Results: Compared with the experimental group and the control group,the number of oocytes obtained after ovulation induction was significantly lower in the experimental group than in the control group(P<0.05),the in vitro fertilization resulted in a significantly lower rate of formation of both cells and blastocyst(P<0.05),the expression of OCT-4 and SOX-2 in embryos was also significantly lower than that in the control group(P<0.05).Conclusions: LPS may affect the development of follicle and the quality of oocyte,which leads to the decrease of the oviposition rate,the two cell rate and the blastocyst formation rate,and the decrease of the blastocyst maturity,which may be related to the decrease of the expression level of OCT-4 and SOX-2.The results provided a theoretical basis for the correlation between inflammation and infertility,especially the development of oocytes and embryos/blastulas.