The Role Of Coenzyme Q10 During Postovulatory Aging Of Mouse Oocyte

The postovulatory aging of oocytes are not only an important cause of low fertilization rate in vitro,poor embryo development,but also one of the reasons that affect the research of assisted reproductive technology(ART).Coenzyme Q10(Coq10)is one of the substances involved in the electron transport chain(ETC)and aerobic respiration in the mitochondria of cells.Coenzyme Q10 protects cells from free radical oxidative damage and reduces oocyte apoptosis that plays an important role in the antioxidant system.Therefore,it is very meaningful to study the mechanism by which CoQ10 can alleviate the aging of mouse oocytes after ovulation.In this study,an oocyte oxidative stress model was established in vitro after 13 hours of superovulation.The culture model was established in vitro for 6h,12 h,and 24 h,and 0μM,1μM,5 μM and 10 μM different concentrations of Coq10 were added to the culture medium during the in vitro culture.Embryo live dyeing,parthenogenetic activation,IVF-ET,Immunofluorescence and other techniques were used to study the role of coenzyme Q10 in the in vitro culture of oocytes.The results showed that after 12 hours of in vitro culture,the degree of oocyte fragmentation was significantly higher than that of fresh oocytes(93.07% vs.51.59%);the abnormal rate of spindle was significantly increased(51.42% vs.10.25%).The oocyte membrane potential is decreased,and the mitochondrial distribution is not evenly distributed.And the amount of ATP synthesis in aged aging oocytes were decreased and SIRT4 was increased.The study found that the addition of 10 μM in the aging group was the optimal concentration of CoQ10,and the blastula formation rate was significantly increased compared with the non-added coenzyme Q10 aging group(53.35% vs.24.28%),and the increase in SIRT4 was inhibited.In addition,Co Q10 not only reduced the production of reactive oxygen species(ROS)in oxidatively damaged oocytes,abnormal spindle levels and oocyte apoptosis,but also maintained the function of oocyte mitochondria.By interfering with the expression of SIRT4,it was confirmed that Coenzyme Q10 delayed the in vitro oocyte aging by inhibiting the expression of SIRT4.In summary,CoQ10 enhances the in vitro fertilization rate and blastocyst rate of aged oocytes by regulating the function of oocyte mitochondria,maintaining the normal structure of the spindle,and inhibiting the increase of sirt4 level,and reducing the aging speed of oocytes after ovulation.Providing experimental data support for research on assisted reproductive technology(ART).