Cathepsin B Activity is Related to the Quality of Bovine Cumulus Oocyte Complexes and Its Inhibition Can Improve Their Developmental Competence
Cathepsin B Activity is Related to the Quality of Bovine Cumulus Oocyte Complexes and Its Inhibition Can Improve Their Developmental Competence
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DOI：
10.1002/mrd.21164
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发表时间：
2010-05-01
影响因子：
2.5
通讯作者：
Takahashi, M.
中科院分区：
文献类型：
--
作者：
Balboula, A. Z.;Yamanaka, K.;Takahashi, M.
最近，卵丘细胞中组织蛋白酶转录本的数量被发现与牛卵母细胞的低发育能力有关。我们研究了（1）组织蛋白酶B活性与卵丘卵母细胞体外成熟复合体质量的关系（2）组织蛋白酶B抑制剂（E-64）的作用对胚胎发育和质量的影响在IVM COC和裸露的卵母细胞中评价组织蛋白酶B的活性。在有或没有E-64的COC成熟后，接着进行体外受精，受精卵培养8天。分别在第2天和第8天评价卵裂率和胚泡率。通过第8天囊胚的差异染色来评价胚胎的质量。在IVM COCs和囊胚上进行TUNEL染色。在低质量卵母细胞中以及在高质量卵母细胞和低质量卵母细胞的卵丘细胞中清楚地检测到组织蛋白酶B活性。IVM过程中E-64的存在也显著增加了囊胚率和总细胞数，TUNEL染色显示，组织蛋白酶B活性的抑制可显著降低成熟卵母细胞卵丘细胞层和囊胚中凋亡核的数量。这些结果表明，组织蛋白酶B活性可作为一种有用的标记物，卵母细胞质量此外，组织蛋白酶B的抑制大大提高了牛卵母细胞的发育能力，并增加了高质量胚胎的数量。
Recently, the quantity of cathepsin transcripts in cumulus cells was found to be associated with low-developmental competence of bovine oocytes In the present study, we investigated (1) the relation between cathepsin B activity and the quality of in vitro-matured cumulus oocyte complexes (IVM COCs) and denuded oocytes and (2) the effect of a cathepsin B inhibitor (E-64) on embryo development and quality The activity of cathepsin B was evaluated in IVM COCs and denuded oocytes After maturation of COCs with or without E-64, followed by in vitro fertilization, zygotes were cultured for 8 days Cleavage and blastocyst rates were evaluated on days 2 and 8, respectively. Quality of embryos was evaluated by differential staining of day 8 blastocysts TUNEL staining was conducted on IVM COCs and blastocysts Cathepsin B activity was clearly detected in the low-quality oocytes, and in the cumulus cells of both high- and low-quality oocytes This latter activity was diminished by addition of E-64. The presence of E-64 during IVM also significantly increased both the blastocyst rate and the total cell number, and improved blastocyst quality associated with a significant increase of trophoectoderm cells TUNEL staining revealed that inhibition of cathepsin B significantly decreased the number of apoptotic nuclei in both the cumulus cell layer of matured oocytes and blastocysts These results indicate that cathepsin B activity can be a useful marker of oocyte quality Furthermore, inhibition of cathepsin B greatly improves the developmental competence of bovine oocytes and increases the number of high-quality embryos.