Glis1 Activate Glycolytic Process and Increase H3K27Ac Level on Pluripotent and Second Wave Genes Promoter Facilitating Pluripotency Induction [ChIP-Seq]

Metabolic activity possess a crucial role during cell fate determination. Here, we show that maternal transcriptional factor Glis1 could not only promote normal MEF reprogramming but also enable aging MEF reprogramming. By association ChIP-seq and RNA-seq, we found that Glis1 could bind and activate glycolytic genes, and bind and suppress somatic state genes simultaneously during reprogramming. While knockdown phosphoglyceric kinase (Pgk1) impeded reprogramming efficiency which indicates that Glis1-glycolytic process axes is required for Glis1 function. Metabolic analysis indicated that the level of acetyl-CoA has a significant fluctuation upon Glis1 induction or silence. Acetate, a precursor of acetyl-CoA rescued the effects on reprogramming in a time-dependent manner when knockdown endogenous Glis1. The fluctuation of Ac-CoA changed the level of H3K27Ac, especially in pluripotent genes and “second wave” genes promoter, and activated the expression of endogenous pluripotency genes in advance subsequently. In conclusion, we demonstrate the exactly novel mechanism of Glis1 in pluripotency acquisition. Examination of Glis1 binding during reprogramming process and histone modifications H3K27Ac in SKO+Flag,SKO+Glis1 on day 5 and day8

代谢活性在细胞命运决定过程中发挥关键作用。本研究证实，母源转录因子Glis1不仅可促进正常小鼠胚胎成纤维细胞（MEF）的重编程，还能实现衰老小鼠胚胎成纤维细胞的重编程。通过联合分析染色质免疫共沉淀测序（ChIP-seq）与RNA测序（RNA-seq）数据，我们发现Glis1在重编程过程中可同时结合并激活糖酵解基因，亦可结合并抑制体细胞状态基因。敲低磷酸甘油酸激酶（Pgk1）会阻碍重编程效率，这表明Glis1-糖酵解通路轴是Glis1发挥功能所必需的。代谢组分析显示，在Glis1诱导表达或基因沉默后，乙酰辅酶A（acetyl-CoA）的水平发生显著波动。当内源Glis1被敲低时，作为乙酰辅酶A前体的乙酸盐可通过时间依赖性方式挽救重编程缺陷。乙酰辅酶A的水平变化会改变组蛋白H3赖氨酸27乙酰化（H3K27Ac）的水平，尤其是在多能基因与"第二波"基因的启动子区域，并随后提前激活内源性多能基因的表达。综上，我们阐明了Glis1介导多能性获得的全新分子机制。此外，本研究还检测了重编程过程中Glis1的结合特征，以及第5天和第8天时SKO+Flag、SKO+Glis1样本中的组蛋白H3K27乙酰化修饰水平。