Mao Jian, Zhang Qian, Deng Wei, Wang Hua, Liu Kai, Fu Haifeng, Zhao Qiang, Wang Xumin, Liu Lin
State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China.
Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
Stem Cell Reports. 2017 Jan 10;8(1):11-20. doi: 10.1016/j.stemcr.2016.11.013. Epub 2016 Dec 29.
Inadequate silencing of exogenous genes represents a major obstacle to complete epigenetic reprogramming of porcine-induced pluripotent stem cells (piPSCs) by conventional pluripotency transcription factors (OSKM). We tested the hypothesis that epigenetic modification by active DNA or histone demethylation or by inhibition of histone deacetylase would enhance reprogramming and exogenous gene silencing in piPSCs. piPSCs induced by OSKM in combination with epigenetic factors, specifically Ten-Eleven Translocation (Tet1 or Tet3) or lysine (K)-specific demethylase 3A (Kdm3a), expressed higher levels of Rex1 and other genes representing naive state and exhibited more open chromatin status, compared with those of OSKM controls. Tet1 also improved differentiation capacity. Conversion with inhibitors of histone deacetylases (HDACi), NaB, TSA, or VPA, further increased Rex1 expression, while decreasing expression of exogenous genes. piPSCs induced by Tet1+OSKM followed by conversion with HDACi show high pluripotency. Together, epigenetic modifiers enhance generation of piPSCs and reduce their reliance on exogenous genes.
对外源基因的沉默不足是通过传统多能性转录因子（OSKM）对猪诱导多能干细胞（piPSCs）进行完全表观遗传重编程的主要障碍。我们测试了这样一个假设，即通过活性DNA或组蛋白去甲基化或通过抑制组蛋白脱乙酰酶进行表观遗传修饰会增强piPSCs的重编程和外源基因沉默。与OSKM对照组相比，由OSKM与表观遗传因子（特别是Tet1或Tet3）或赖氨酸（K）特异性去甲基化酶3A（Kdm3a）联合诱导的piPSCs表达更高水平的Rex1和其他代表原始状态的基因，并表现出更开放的染色质状态。Tet1还提高了分化能力。用组蛋白脱乙酰酶抑制剂（HDACi）、丁酸钠（NaB）、曲古抑菌素A（TSA）或丙戊酸（VPA）进行转化，进一步增加了Rex1的表达，同时降低了外源基因的表达。由Tet1+OSKM诱导并随后用HDACi转化的piPSCs表现出高多能性。总之，表观遗传修饰剂增强了piPSCs的生成并减少了它们对外源基因的依赖。
