J Pineal Res:农科院朱化彬研究组发表卵母细胞冷冻凋亡抑制研究成
2016年3月，国际学术期刊《Journal of Pineal Research》杂志上在线发表中国中国农业科学院北京畜牧兽医研究所家畜胚胎工程与繁殖创新团队卵母细胞冷冻凋亡抑制研究取得重要进展。该研究利用褪黑素抑制玻璃化冷冻牛卵母细胞中线粒体介导的凋亡通路，提高了其体外发育能力。朱化彬研究员为论文通讯作者。
卵母细胞冷冻保存是哺乳动物胚胎生物工程的重要技术环节，但是冷冻过程中发生细胞凋亡引起卵母细胞发育能力下降，成为限制冷冻卵母细胞应用的重要瓶颈。
研究以牛卵母细胞为研究对象，通过在卵母细胞体外成熟液、玻璃化冷冻液中添加10-9M褪黑素，重点研究了褪黑素对玻璃化冷冻牛卵母细胞中ROS、线粒体Ca2+(mCa2+)及膜电位(Δψ)、PS外翻、Caspase-3激活、DNA断裂、Bax/Bcl2l1基因mRNA表达及其发育能力的影响。研究结果发现，添加褪黑素能够显著降低牛卵母细胞中ROS、mCa2+、Bax mRNA、Caspase 3蛋白、PS外翻和DNA断裂水平，提高Δψ、Bcl2l1及卵母细胞发育能力，因而显著提高玻璃化冷冻后卵母细胞发育能力。该研究成果对牛卵母细胞冷冻保存及其广泛应用具有重要意义
原文链接：
Melatonin inhibits apoptosis and improves the developmental potential of vitrified bovine oocytes
原文摘要：
Vitrification of oocytes has been shown to be closely associated with increased levels of reactive oxygen species (ROS) and apoptotic events. However, little information is available the effect of melatonin on the ROS levels and apoptotic events in vitrified oocytes. Therefore, we studied the effect of melatonin on ROS and apoptotic events in vitrified bovine oocytes by supplementing vitrification solution or in vitro maturation (IVM) and vitrification solution with 10−9 m melatonin. We analyzed the ROS, mitochondrial Ca2+ (mCa2+) and membrane potential (ΔΨm), externalization of phosphatidylserine (PS), caspase-3 activation, DNA fragmentation, mRNA expression levels of Bax and Bcl2 l1, and developmental potential of vitrified bovine oocytes. Vitrified bovine oocytes exhibited increased levels of ROS, mCa2+, Bax mRNA, and caspase-3 protein and higher rates of PS externalization and DNA fragmentation, and decreased ΔΨm and Bcl2 l1 mRNA expression level. However, melatonin supplementation in vitrification solution or IVM and vitrification solution significantly decreased the levels of ROS, mCa2+, Bax mRNA expression, and caspase-3 protein, and PS externalization and DNA fragmentation rates, and increased the ΔΨm and Bcl2 l1 mRNA expression level in vitrified oocytes, resulting in an increased developmental ability of vitrified bovine oocytes after parthenogenetic activation. The developmental ability of vitrified oocytes with melatonin supplementation in IVM and vitrification solution was similar to that of fresh ones. This study showed that supplementing the IVM and vitrification medium or vitrification medium with 10−9 m melatonin significantly decreased the ROS level and inhibited apoptotic events of vitrified bovine oocytes, consequently increasing their developmental potential.
作者：朱化彬
