PDF(Pubmed)
Abstract：
HDAC6 is an essential factor in mouse oocyte maturation. However, the roles of HDAC6 in porcine oocyte maturation are still unclear. Therefore, we analyzed the roles of HDAC6 in porcine oocyte maturation by treatment with Tubastatin A (TubA) which is an HDAC6 inhibitor. Our results showed that treatment with 10 μg/ml TubA significantly decreased the rate of porcine oocyte maturation, but it did not influence the rate of germinal vesicle breakdown (GVBD). Then, we found that TubA treatment disrupted spindle organization by increasing the α-tubulin acetylation level during porcine oocyte maturation. Moreover, TubA treatment significantly increased H4K16 acetylation, which may compromise kinetochore and microtubule (K-MT) attachment during meiosis in porcine oocytes. We also analyzed the effects of TubA on meiosis-related (H3T3pho and H3S10pho) and transcription-related histone modifications (H3K4me3, H3K9me3 and H3K4ac) during porcine oocyte maturation. The results showed that TubA treatment increased H3S10pho and H3K4ac levels, but no influence was seen in H3T3pho, H3K4me3 and H3K9me3 levels in porcine oocytes. TubA treated oocytes also showed a compromised ability to develop after parthenogenetic activation. Finally, we found that HDAC6 exhibited higher mRNA levels and lower DNA methylation levels in porcine oocytes than it did in porcine embryonic fibroblasts (PEFs). These results indicate that the low level of DNA methylation in HDAC6 promoter ensures high expression. HDAC6 regulates the deacetylation of α-tubulin and H4K16, which promotes correct spindle organization and meiotic apparatus assembly during porcine oocyte maturation. This study illustrates a new pathway by which HDAC6 modulates mammalian oocyte maturation.
摘要：
HDAC6是小鼠卵母细胞成熟的重要因子。然而,HDAC6在猪卵母细胞成熟中的作用尚不清楚。因此,我们分析了HDAC6在猪卵母细胞成熟过程中的作用。我们的结果表明，用10μg/mlTubA处理显著降低猪卵母细胞的成熟率，但不影响生发囊泡破裂（GVBD）的发生率。然后，我们发现TubA处理通过增加猪卵母细胞成熟过程中的α-微管蛋白乙酰化水平来破坏纺锤体组织。此外，TubA处理显著增加H4K16乙酰化，这可能会损害猪卵母细胞减数分裂过程中的动粒和微管（K-MT）附着。我们还分析了TubA对猪卵母细胞成熟过程中减数分裂相关（H3T3pho和H3S10pho）和转录相关组蛋白修饰（H3K4me3，H3K9me3和H3K4ac）的影响。结果表明，TubA处理增加了H3S10pho和H3K4ac的水平，但是在H3T3pho中没有看到影响，H3K4me3和H3K9me3在猪卵母细胞中的水平。TubA处理的卵母细胞在孤雌生殖激活后也表现出受损的发育能力。最后,我们发现HDAC6在猪卵母细胞中的mRNA水平和DNA甲基化水平高于在猪胚胎成纤维细胞(PEFs)中的水平.这些结果表明,HDAC6启动子中的低水平DNA甲基化确保了高表达。HDAC6调节α-微管蛋白和H4K16的去乙酰化，从而促进猪卵母细胞成熟过程中正确的纺锤体组织和减数分裂器组装。这项研究说明了HDAC6调节哺乳动物卵母细胞成熟的新途径。
