Gao Min, Li Xiaoyan, He Yongfu, Han Longsen, Qiu Danhong, Ling Li, Liu Honglin, Liu Jianguo, Gu Ling
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China.
FASEB J. 2018 Jun 7:fj201800078RR. doi: 10.1096/fj.201800078RR.
SIRT7, a member of the sirtuin family, with coenzyme NAD catalyzes protein deacetylation and has been implicated in multiple biologic processes; however, its function in mammalian oocytes remains to be explored. Here, we report disrupted meiotic maturation upon specific knockdown of SIRT7 in mouse oocytes. In particular, disorganized spindle/chromosomes and the loss of the cortical actin cap are readily observed in SIRT7-depleted oocytes, generating aneuploid eggs. Furthermore, we found that SIRT7 depletion markedly elevated reactive oxygen species levels in oocytes, thereby compromising the developmental competence of early embryos. Of note, SIRT7 protein level is significantly decreased in oocytes from obese mice, and the forced expression of exogenous SIRT7 ameliorates maternal obesity-associated meiotic defects and oxidative stress in oocytes. In summary, our data suggest that SIRT7 is an essential factor in the determination of oocyte quality and may mediate the effects of obesity on female reproduction.-Gao, M., Li, X., He, Y., Han, L., Qiu, D., Ling, L., Liu, H., Liu, J., Gu, L. SIRT7 functions in redox homeostasis and cytoskeletal organization during oocyte maturation.
SIRT7是沉默调节蛋白家族的一员，它与辅酶NAD一起催化蛋白质去乙酰化作用，并参与多种生物学过程；然而，其在哺乳动物卵母细胞中的功能仍有待探索。在此，我们报道了在小鼠卵母细胞中特异性敲低SIRT7后减数分裂成熟过程受到破坏。具体而言，在SIRT7缺失的卵母细胞中很容易观察到纺锤体/染色体紊乱以及皮质肌动蛋白帽的缺失，从而产生非整倍体卵子。此外，我们发现SIRT7缺失显著提高了卵母细胞中的活性氧水平，进而损害了早期胚胎的发育能力。值得注意的是，肥胖小鼠卵母细胞中的SIRT7蛋白水平显著降低，而外源SIRT7的强制表达改善了与母体肥胖相关的卵母细胞减数分裂缺陷和氧化应激。总之，我们的数据表明SIRT7是决定卵母细胞质量的一个关键因素，并且可能介导肥胖对雌性生殖的影响。——高，M.，李，X.，何，Y.，韩，L.，邱，D.，凌，L.，刘，H.，刘，J.，顾，L. SIRT7在卵母细胞成熟过程中的氧化还原稳态和细胞骨架组织中发挥作用。
