Kansaku Kazuki, Takeo Shun, Itami Nobuhiko, Kin Airi, Shirasuna Koumei, Kuwayama Takehito, Iwata Hisataka
Department of Animal Science, Tokyo University of Agriculture, Atsugi City, Kanagawa, Japan.
PLoS One. 2017 Nov 28;12(11):e0188099. doi: 10.1371/journal.pone.0188099. eCollection 2017.
Mitochondrial quality control is important for maintaining cellular and oocyte viability. In addition, aging affects mitochondrial quality in many cell types. In the present study, we examined how aging affects oocyte mitochondrial biogenesis and degeneration in response to induced mitochondrial dysfunction. Cumulus oocyte complexes were harvested from the ovaries of young (21‒45 months) and aged (≥120 months) cows and treated for 2 hours with 10 μM carbonyl cyanide-m- chlorophenylhydrazone (CCCP), or a vehicle control, after which cumulus oocyte complexes were subjected to in vitro fertilization and culture. CCCP treatment reduced ATP content and increased reactive oxygen species (ROS) levels in the oocytes of both young and aged cows. When CCCP-treated cumulus oocyte complexes were subsequently cultured for 19 hours and/or subjected to fertilization, high ROS levels in oocytes and a low rate of blastocyst development was observed in oocytes derived from aged cows. In addition, we observed differential responses in mitochondrial biogenesis to CCCP treatment between young and aged cows. CCCP treatment enhanced mitochondrial biogenesis concomitant with upregulation of SIRT1 expression in oocytes of young, but not aged, cows. In conclusion, aging affects mitochondrial quality control and recuperation of oocytes following CCCP-induced mitochondrial dysfunction.
线粒体质量控制对于维持细胞和卵母细胞的活力很重要。此外,衰老会影响多种细胞类型中的线粒体质量。在本研究中,我们研究了衰老如何影响卵母细胞的线粒体生物发生以及对诱导的线粒体功能障碍的退化反应。从年轻(21至45个月)和老龄(≥120个月)母牛的卵巢中收集卵丘卵母细胞复合体,并用10μM羰基氰化物间氯苯腙(CCCP)或载体对照处理2小时,之后将卵丘卵母细胞复合体进行体外受精和培养。CCCP处理降低了年轻和老龄母牛卵母细胞中的ATP含量并增加了活性氧(ROS)水平。当将经CCCP处理的卵丘卵母细胞复合体随后培养19小时和/或进行受精时,在老龄母牛来源的卵母细胞中观察到卵母细胞中高ROS水平和低囊胚发育率。此外,我们观察到年轻和老龄母牛对CCCP处理的线粒体生物发生有不同反应。CCCP处理增强了年轻母牛而非老龄母牛卵母细胞中的线粒体生物发生,并伴随SIRT1表达上调。总之,衰老会影响CCCP诱导的线粒体功能障碍后卵母细胞的线粒体质量控制和恢复。