| Mitoquinone(MitoQ)is combined covalently with a triphenylphosphonic acid cation and a benzoquinone part of coenzyme Q10 by a ten carbon fatty chain.MitoQ can accumulate in the mitochondria after going through the mitochondrial membrane because of the triphenyl phosphate cation and transform into antioxidant active coenzyme Q10 reused by respiratory chain complex ?.MitoQ protects mitochondria by reducing mitochondrial reactive oxygen species(ROS)levels,mitochondrial protein and lipid and DNA oxidative damage and changes participation in reactive oxygen species(ROS)signal transduction pathways.Cell apoptosis and oxidant damage of porcine oocytes during vitrification thawing and resuscitation are considered to be the main factors affecting post-freezing development of porcine oocytes.However,there are few reports on the oxidative stress and apoptosis of porcine oocytes after freezing.This paper is to explore the effect of MitoQ on the vitro development of porcine oocytes by adding MitoQ in the whole process of culture and maturation.In vitro Maturation Culture and after vitrification of porcine oocytes,MitoQ was added during resuscitation incubation after freezing to study oxidation opoptosis pathways in porcine oocytes and parthenogenetically activated embryos and the improvement of MitoQ on the development of porcine oocytes after freezing.This test mainly includes two parts:The first part of the study is the effect of MitoQ on vitro maturation of porcine oocytes.MitoQ was added into porcine oocyte maturation medium and to study the effect of MitoQ on the vitro maturation and development of porcine oocytes by detecting mitochondrial membrane potential(JC-1),early apoptosis(AnnexinV-FITC),embryonic development,lipid oxidation(MDA),reactive oxygen species(ROS).The results showed that the mitochondrial membrane potential of MitoQ-incubated oocytes(1.66±0.06)was significantly higher than that of fresh oocytes(1.37±0.05)(P<0.05);the early apoptosis rate of MitoQ-incubated oocytes was(2.72±0.62%)was significantly lower than that of fresh oocytes(9.05±0.71%)(P<0.05);reactive oxygen level(5.82±0.64)and malondialdehyde content(6.07±1.17)of Mito Q-incubated oocytes were significantly decreased compared with fresh oocytes(13.06±0.72 and 10.64±0.82)(P<0.05);parthenogeneticallyactivated cleavage rate(71.99±1.15%)and blastocyst rate(17.70±0.80%)of the Mito Q-incubated oocytes were significantly increased compared with fresh oocytes(63.77±1.40% and 11.25±0.67%)(P<0.05).The expression levels of Bcl-2,CuZnSOD,and DNM1 in MitoQ-incubated oocytes were significantly higher than control group(P<0.05).The expression levels of Bax and TNF-? in MitoQ-incubated oocytes were significantly decreased(P<0.05).In summary,the addition of MitoQ in the progress of porcine oocytes culture can improve mitochondrial function,reduce oxidative stress,inhibit apoptosis and improve the expression of related genes,thereby improving in vitro development of porcine oocytes.The second part of the study is the effect of MitoQ on oxidative stress injury and apoptosis of porcine oocytes after freezing.The experimental group was supplemented with 200nmol/L MitoQ in the oocyte culture medium,vitrified after the culture was mature,continued to add MitoQ during the thawing and resuscitation,and tested for parthenogenetic cleavage rate,blastocyst rate,Annexin V-FITC,and mitochondria.Membrane potential JC-1,malondialdehyde(MDA),reactive oxygen species(ROS)and related gene expression levels.The results showed that after Mito Q oocytes were frozen,their mitochondrial membrane potential(0.66±0.06)was significantly higher than that of the control group(0.47±0.05)(P<0.05),and the rate of early apoptosis was(43.00±3.51%).The control group(55.33±1.45%)had a significant decrease(P<0.05);MitoQ treated oocytes after freezing had ROS(3.03±0.61)and lipid oxidation(20.54±0.91)and control group(13.13).There was a significant decrease in ±1.52 compared with 26.78±0.54)(P<0.05);the survival rate of MitoQ-treated oocytes after freezing was 60.33±1.86%,the cleavage rate was 28.82±1.38%,and the blastocyst rate was 4.50± 0.48%)was significantly increased compared to the control group(47.67±1.67%,22.07±1.07%,and 2.20±0.51%);in terms of gene expression,MitoQ-treated group was frozen after freezing compared to the control group.The expression levels of Bcl-2,CuZnSOD and Mfn2 were significantly increased(P<0.05),and the relative expression levels of DNM1,Bax and TNF-? were significantly decreased(P<0.05).In summary,the addition of MitoQ in the frozen medium can improve mitochondrial function,reduce the level of oxidative stress,inhibit apoptosis and improve the expression level of related genes,thus improving the in vitro development of porcine oocytes after freezing.Summary: MitoQ can improve the mitochondrial function,alleviating cellular oxidative damage,reduce the level of apoptosis,which play before and after the effect of promoting in vitro developmental competence of oocytes. |
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