Changes in mitochondrial function in porcine vitrified MII-stage oocytes and their impacts on apoptosis and developmental ability

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• 作者：Jianjun Dai^a ; ^b ; ^c ; Caifeng Wu^b ; ^c ; Caroline W. Muneri^a ; Yingfang Niu^b ; ^c ; Shushan Zhang^b ; ^c ; Rong Rui^a ; ^{rrui@njau.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Defu Zhang^b ; ^c ; ^{zhangdefuzdf@163.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Porcine ; MII-stage oocyte ; OPS vitrification ; Mitochondria ; Apoptosis
• 刊名：Cryobiology
• 出版年：2015
• 出版时间：October 2015
• 年：2015
• 卷：71
• 期：2
• 页码：291-298
• 全文大小：1264 K

文摘

The purpose of this study was to investigate the changes in mitochondria in porcine MII-stage oocytes after open pulled straw (OPS) vitrification and to determine their roles in apoptosis and in vitro developmental ability. The mitochondrial membrane potential (螖唯m), reactive oxygen species (ROS) level, adenosine-5′-triphosphate (ATP) concentration, mitochondrial distribution, mitochondrial ultrastructure, early-stage apoptosis with Annexin V-FITC staining, survival rate, parthenogenetic developmental ability and related gene expression were measured in the present experiments. The results showed that: (1) the mitochondrial 螖唯m of vitrified-thawed oocytes (1.05) was lower than that of fresh oocytes 1.24 (P < 0.05). (2) ROS level in the OPS vitrification group was much higher than that of the fresh group, while the ATP concentration was much lower than that of fresh group (P < 0.05). (3) Early-stage apoptosis rate from the OPS vitrification group (57.6%) was much higher than that of fresh group (8.53%) (P < 0.05), and the survival rate and parthenogenetic cleavage rate of OPS vitrified oocytes were much lower than those from fresh ones (P < 0.05). (4) Vitrification not only disrupted the mitochondrial distribution of porcine MII-stage oocytes, but also damaged the mitochondrial ultrastructure. (5) After vitrification, the gene expression level of Dnm1 was up-regulated, and other four genes (SOD1, Mfn2, BAX and Bcl2) were down-regulated. The present study suggested that not only the morphology and function of mitochondria were damaged greatly during the vitrification process, but also early-stage apoptosis was observed after vitrification. Intrinsic mitochondrial pathway could be in involved in the occurrence of apoptosis in vitrified-thawed porcine oocytes.