Saini Monika, Selokar Naresh L, Agrawal Himanshu, Singla Suresh Kumar, Chauhan Manmohan Singh, Manik Radheysham S, Palta Prabhat
Embryo Biotechnology Laboratory, Animal Biotechnology Centre, ICAR-National Dairy Research Institute , Karnal, India .
Cell Reprogram. 2017 Jun;19(3):208-215. doi: 10.1089/cell.2016.0061. Epub 2017 May 2.
The application of cloning technology on a large scale is limited by very low offspring rate primarily due to aberrant or incomplete epigenetic reprogramming. Trichostatin A (TSA), a histone deacetylase inhibitor, and 5-aza-2'-deoxycytidine (5-aza-dC), an inhibitor of DNA methyltransferases, are widely used for altering the epigenetic status of cloned embryos. We optimized the doses of these epigenetic modifiers for production of buffalo embryos by handmade cloning and examined whether combined treatment with these epigenetic modifiers offered any advantage over treatment with the individual epigenetic modifier. Irrespective of whether donor cells or reconstructed embryos or both were treated with 50 nM TSA +7.5 nM 5-aza-dC, (1) the blastocyst rate was significantly higher (71.6 ± 3.5, 68.3 ± 2.6, and 71.8 ± 2.4, respectively, vs. 43.1 ± 3.4 for controls, p < 0.05); (2) the apoptotic index was lower (5.4 ± 1.1, 9.5 ± 1.0, and 7.4 ± 1.3, respectively, vs. 19.5 ± 2.1 for controls, p < 0.05) and was similar to that of in vitro fertilization blastocysts (6.0 ± 0.8); (3) the global level of H3K18ac was higher (p < 0.01) and that of H3K27me3 lower (p < 0.05) than in controls and was similar among all treatment groups; and (4) the expression level of epigenetic-(HDAC1, DNMT1, and DNMT3a), pluripotency-(OCT4 and NANOG), and development-related (FGF4) genes, but not that of SOX2 and CDX2, was similar among all treatment groups. These results demonstrate that similar levels of beneficial effects can be obtained following treatment of either donor cells or reconstructed embryos or both with the combination of TSA +5-aza-dC. Therefore, there is no advantage in treating both donor cells and reconstructed embryos when the combination of TSA and 5-aza-dC is used.
克隆技术的大规模应用受到极低后代率的限制,这主要是由于异常或不完全的表观遗传重编程。曲古抑菌素A(TSA)是一种组蛋白脱乙酰酶抑制剂,5-氮杂-2'-脱氧胞苷(5-aza-dC)是一种DNA甲基转移酶抑制剂,它们被广泛用于改变克隆胚胎的表观遗传状态。我们通过手工克隆优化了这些表观遗传修饰剂在水牛胚胎生产中的剂量,并研究了联合使用这些表观遗传修饰剂是否比单独使用一种表观遗传修饰剂具有任何优势。无论供体细胞、重构胚胎或两者都用50 nM TSA + 7.5 nM 5-aza-dC处理,(1)囊胚率显著更高(分别为71.6±3.5、68.3±2.6和71.8±2.4,而对照组为43.1±3.4,p < 0.05);(2)凋亡指数更低(分别为5.4±1.1、9.5±1.0和7.4±1.3,而对照组为19.5±2.1,p < 0.05),且与体外受精囊胚的凋亡指数相似(6.0±0.8);(3)H3K18ac的整体水平高于对照组(p < 0.01),H3K27me3的水平低于对照组(p < 0.05),且在所有处理组中相似;(4)表观遗传相关基因(HDAC1、DNMT1和DNMT3a)、多能性相关基因(OCT4和NANOG)以及发育相关基因(FGF4)的表达水平在所有处理组中相似,但SOX2和CDX2的表达水平并非如此。这些结果表明,用TSA + 5-aza-dC组合处理供体细胞、重构胚胎或两者,均可获得相似水平的有益效果。因此,当使用TSA和5-aza-dC组合时,同时处理供体细胞和重构胚胎并无优势。