Heo Jinbeom, Lim Jisun, Lee Seungun, Jeong Jaeho, Kang Hyunsook, Kim YongHwan, Kang Jeong Wook, Yu Hwan Yeul, Jeong Eui Man, Kim Kyunggon, Kucia Magda, Waigel Sabine J, Zacharias Wolfgang, Chen Yinlu, Kim In-Gyu, Ratajczak Mariusz Z, Shin Dong-Myung
Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; Department of Physiology, University of Ulsan College of Medicine, Seoul 05505, Korea.
Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; Department of Physiology, University of Ulsan College of Medicine, Seoul 05505, Korea; Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
Cell Rep. 2017 Feb 21;18(8):1930-1945. doi: 10.1016/j.celrep.2017.01.074.
Embryonic stem cell (ESC) abnormalities in genome methylation hamper the utility of their therapeutic derivatives; however, the underlying mechanisms are unknown. Here, we show that the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase, Sirt1, selectively prevents abnormal DNA methylation of some developmental genes in murine ESCs by antagonizing Dnmt3l. Transcriptome and DNA methylome analyses demonstrated that Sirt1-null (Sirt1) ESCs repress expression of a subset of imprinted and germline genes concomitant with increased DNA methylation of regulatory elements. Dnmt3l was highly expressed in Sirt1 ESCs, and knockdown partially rescued abnormal DNA methylation of the Sirt1 target genes. The Sirt1 protein suppressed transcription of Dnmt3l and physically interacted with the Dnmt3l protein, deacetylating and destabilizing Dnmt3l protein. Sirt1 deficiency delayed neurogenesis and spermatogenesis. These differentiation delays were significantly or partially abolished by reintroduction of Sirt1 cDNA or Dnmt3l knockdown. This study sheds light on mechanisms that restrain DNA methylation of developmentally vital genes operating in ESCs.
胚胎干细胞（ESC）基因组甲基化异常阻碍了其治疗性衍生物的应用；然而，其潜在机制尚不清楚。在此，我们表明烟酰胺腺嘌呤二核苷酸（NAD）依赖性脱乙酰酶Sirt1通过拮抗Dnmt3l选择性地防止小鼠胚胎干细胞中某些发育基因的异常DNA甲基化。转录组和DNA甲基化组分析表明，Sirt1基因敲除（Sirt1 -/-）的胚胎干细胞抑制了一部分印记基因和种系基因的表达，同时调控元件的DNA甲基化增加。Dnmt3l在Sirt1 -/-胚胎干细胞中高表达，敲低Dnmt3l可部分挽救Sirt1靶基因的异常DNA甲基化。Sirt1蛋白抑制Dnmt3l的转录，并与Dnmt3l蛋白发生物理相互作用，使Dnmt3l蛋白去乙酰化并使其不稳定。Sirt1基因缺陷会延迟神经发生和精子发生。通过重新引入Sirt1 cDNA或敲低Dnmt3l，这些分化延迟被显著或部分消除。这项研究揭示了抑制胚胎干细胞中对发育至关重要的基因DNA甲基化的机制。
