| Oocyte maturation in vitro(IVM)is an important step in animal embryo biotechnology,it has applied in vitro fertilization,nuclear transfer and transgenic technology and so on.There are many factors affecting oocyte maturation in vitro,such as mature culture environment conditions,nutrient composition of mature liquid,culture time and so on.Many studies have found that the accumulation of reactive oxygen species(ROS)produced in the process of in vitro culture may cause oxidative stress in oocytes,resulting in maturation arrest and abnormal meiosis of oocytes,resulting in embryo development arrest and embryo death after fertilization or activation.Lycium barbarum polysaccharide(LBP),as the active ingredient of lycium barbarum extract,has antioxidant,anti-aging and anti-inflammatory effects.It has been proved that LBP could reduce ROS content in vitrified frozen mouse oocytes,and it is speculated that LBP can also reduce oxidative stress of oocytes in vitro maturation.Based on this,we explored the role and mechanism of LBP in porcine oocytes in vitro maturation and early embryo development.The results of this study are as follows:1 、 Effects of Lycium Barbarum Polysaccharide on porcine oocytes in vitro maturation and early embryo development.The results showed that compared with the untreated group,100 μg/m L LBP in mature medium significantly increased the first pole excretion rate of oocytes,the division rate,4-cell rate and blastocyst rate of IVF embryos(P<0.05).DCFH-DA staining solution was used to detect the ROS content in oocytes.It was found that compared with the untreated group,the ROS content in oocytes treated with 100 μg/m L LBP was significantly decreased,and the ROS content in 200 μg/m L group was significantly increased(P<0.05).The GSH-Px activity of porcine oocytes in 100 μg/m L group was significantly increased(P<0.05),but there was no difference in 200μg/m L group(P>0.05).It was found that 100 μg/m L LBP promoted the expansion of cumulus cells(P<0.05),and 100 μg/m L LBP was used for subsequent treatment.Compared with the untreated group,100 μg/m L LBP treatment significantly decreased the rate of polyspermy,and significantly increased the rate of monospermy(P<0.05).q RT-PCR results showed that LBP significantly up-regulated the expression levels of antioxidant related genes CAT,SOD1,GPX4 and apoptosis suppressor gene BCL2,and significantly down-regulated the expression of apoptosis gene BAX(P<0.05).2 、 Preliminary study on the synergistic effect of Lycium barbarum polysaccharide(LBP)on improving antioxidant activity of porcine oocytes through Nrf2 signaling pathway and peroxisome activitites.Brusatol,a specific inhibitor of Nrf2,was added with different concentrations during the in vitro maturation of porcine oocytes.Compared with the untreated group,Brusatol at 4 n M significantly reduced the first polar excretion rate of porcine oocytes(73.27 VS62.6),IVF embryo division rate(46.53 VS 35.51),4-cell rate(40.59 VS29.90),blastocyst rate(11.88 VS 7.47)(P<0.05).Brusatol at 4 n M significantly inhibited the expansion of porcine cumulus cells(P<0.05).q RT-PCR results showed that LBP treatment significantly increased the expression of Nrf2 and peroxisome-related genes PEX3,PEX5,PEX19,PHYH,PPARγ(P<0.05).Immunofluorescence results showed that compared with the untreated group,the expression of Nrf2 in porcine oocytes was significantly increased by LBP alone and Brusatol combined treatment(P<0.05),while the expression of Nrf2 in Brusatol group was significantly decreased(P<0.05).The above results indicate that appropriate LBP treatment can improve the in vitro maturation efficiency of porcine oocytes and early embryo development potential.LBP may play a role by activating the Nrf2 signaling pathway and enhancing peroxisomal activities. |
PDF Full Text Request