Effect Of Glutamate On Antioxoidant Level And Subsequent Development Of In Vitro Cultured Mouse Embryos In The Blocking Stage

During the in vitro culture of embryos,they are easily affected by various exogenous and endogenous factors and produce excessive reactive oxygen species.Because it is impossible to fully simulate the developmental environment of the embryo in vivo,and the lack of protection of the antioxidant system in the body causes some embryos to suffer oxidative damage and cannot develop normally.Embryo arrest occurs during the development of mammalian embryos.The large accumulation of reactive oxygen species prevents early embryos from developing at a certain stage and leads to embryo death.Therefore,in order to solve this problem,substances such as antioxidants are usually added to the in vitro culture medium to protect the normal development of early embryos.Glutamate is an important and more common functional amino acid,which plays an irreplaceable role in protecting cell metabolism and regulating intracellular signaling.The purpose of this study was to investigate the effects of glutamate on early embryonic mouse culture in vitro.The test was divided into a glutamate treated group and a M16 control group.By performing embryonic reactive oxygen content in embryos at the 2-cell,4-cell,and blastocyst stages of Kunming mice(blocking strain),GSH level and mitochondrial membrane potentials were detected and analyzed.Then,the expression levels of GPx and Nrf2 and its related genes and cell cycle-related genes in the embryo arrest phase,2-cell and 4-cell embryos were examined.The test results showed that the Glu treated group at a concentration of 6 mmol/L significantly improved the 2-cell to 4-cell transition rate and the blastocyst rate compared with the control group.At the same time,glutamic acid significantly reduced the reactive oxygen content in 2-cell,4-cell and blastocyst embryos,and significantly increased the GSH level and mitochondrial membrane potential in the embryo.After adding glutamic acid to mouse early embryo culture,glutathione-related enzymes(GPx1,GPx2),Nrf2 and their target genes(HO-1,GCLC,CAT,SOD1)in 2-cell and 4-cell embryo mRNA expression is up-regulated.In addition,mRNA expression of cell cycle related genes(cyclin B,CDK1)at the 2-cell stage was also increased.These results indicate that glutamate increases the level of antioxidants by reducing the level of oxidative stress in mice early embryos and improving mitochondrial levels,thereby effectively reducing the risk of embryonic developmental block and improving embryonic developmental capacity.