Identification of novel bovine cumulus cell molecular markers predictive of oocyte competence: Functional and diagnostic implications
Identification of novel bovine cumulus cell molecular markers predictive of oocyte competence: Functional and diagnostic implications
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DOI：
10.1095/biolreprod.107.067223
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发表时间：
2008-08-01
影响因子：
3.6
通讯作者：
Smith, George W.
中科院分区：
文献类型：
--
作者：
Bettegowda, Anilkumar;Patel, Osman V.;Smith, George W.
本研究旨在发现牛卵丘细胞中预测卵母细胞能力的分子标记，并阐明其功能意义。通过微阵列分析确定了从成年与青春期前动物（卵母细胞质量差的模型）的卵母细胞收获的卵丘细胞中RNA转录物丰度的差异。选择编码溶酶体半胱氨酸蛋白酶组织蛋白酶B、S、K和Z的四种感兴趣的基因，并在从青春期前动物收获的卵母细胞周围的卵丘细胞中显示更大的转录物丰度，用于进一步研究。实时RT-PCR证实了这些基因在青春期前卵母细胞卵丘细胞中的mRNA丰度更高。组织蛋白酶B，S和Z的转录丰度升高也观察到周围的卵丘细胞中的成年中期II的卵母细胞发育到囊胚阶段，在孤雌激活后，在低百分比与那些开发在一个高的百分比。卵丘细胞组织蛋白酶表达对卵母细胞能力的功能意义通过在体外卵母细胞成熟过程中用细胞渗透性半胱氨酸蛋白酶（组织蛋白酶）抑制剂处理卵丘-卵母细胞复合物来证实。抑制剂处理减少了卵丘层中的凋亡核，并增强了孤雌激活和体外受精的成年卵母细胞到囊胚阶段的发育。当卵母细胞在没有卵丘细胞的情况下成熟时，未观察到减数分裂成熟期间抑制剂处理对随后胚胎发育的刺激作用。目前的研究结果支持卵丘细胞组织蛋白酶在受损的卵母细胞能力的功能作用，并建议卵丘细胞组织蛋白酶mRNA丰度可能是卵母细胞质量的预测。
The present study was undertaken to discover molecular markers in bovine cumulus cells predictive of oocyte competence and to elucidate their functional significance. Differences in RNA transcript abundance in cumulus cells harvested from oocytes of adult versus prepubertal animals (a model of poor oocyte quality) were identified by microarray analysis. Four genes of interest encoding for the lysosomal cysteine proteinases cathepsins B, S, K, and Z and displaying greater transcript abundance in cumulus cells surrounding oocytes harvested from prepubertal animals were chosen for further investigation. Greater mRNA abundance for such genes in cumulus cells of prepubertal oocytes was confirmed by real-time RT-PCR. Elevated transcript abundance for cathepsins B, S, and Z also was observed in cumulus cells surrounding adult metaphase II oocytes that developed to the blastocyst stage at a low percentage following parthenogenetic activation versus those that developed at a high percentage. Functional significance of cumulus cell cathepsin expression to oocyte competence was confirmed by treatment of cumulus-oocyte complexes during in vitro oocyte maturation with a cell-permeable cysteine proteinase (cathepsin) inhibitor. Inhibitor treatment decreased apoptotic nuclei in the cumulus layer and enhanced development of parthenogenetically activated and in vitro-fertilized adult oocytes to the blastocyst stage. Stimulatory effects of inhibitor treatment during meiotic maturation on subsequent embryonic development were not observed when oocytes were matured in the absence of cumulus cells. The present results support a functional role for cumulus cell cathepsins in compromised oocyte competence and suggest that cumulus cell cathepsin mRNA abundance may be predictive of oocyte quality.