Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India.
Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India.
Gene. 2020 Oct 5;757:144934. doi: 10.1016/j.gene.2020.144934. Epub 2020 Jul 5.
Overexpression of DNA Methyltransferase I (DNMT1) is considered as one of the etiological factors for schizophrenia (SZ). However, information on genes subjected to dysregulation because of DNMT1 overexpression is limited. To test whether a larger group of SZ-associated genes are affected, we selected 15 genes reported to be dysregulated in patients (Gad1, Reln, Ank3, Cacna1c, Dkk3, As3mt, Ppp1r11, Smad5, Syn1, Wnt1, Pdgfra, Gsk3b, Cxcl12, Tcf4 and Fez1). Transcript levels of these genes were compared between neurons derived from Dnmt1 (Tet/Tet) mouse embryonic stem cells (ESCs) that overexpress DNMT1 with R1 (wild-type) neurons. Transcript levels of thirteen genes were significantly altered in Tet/Tet neurons of which, the dysregulation patterns of 11 were similar to patients. Transcript levels of eight out of these eleven were also significantly altered in Tet/Tet ESCs, but the dysregulation patterns of only five were similar to neurons. Comparative analyses among ESCs, embryoid bodies and neurons divided the 15 genes into four distinct groups with a majority showing developmental stage-specific patterns of dysregulation. Reduced Representational Bisulfite Sequencing data from neurons did not show any altered promoter DNA methylation for the dysregulated genes. Doxycycline treatment of Tet/Tet ESCs that eliminated DNMT1, reversed the direction of dysregulation of only four genes (Gad1, Dkk3, As3mt and Syn1). These results suggest that 1. Increased DNMT1 affected the levels of a majority of the transcripts studied, 2. Dysregulation appears to be independent of promoter methylation, 3. Effects of increased DNMT1 levels were reversible for only a subset of the genes studied, and 4. Increased DNMT1 levels may affect transcript levels of multiple schizophrenia-associated genes.
DNA 甲基转移酶 I（DNMT1）的过表达被认为是精神分裂症（SZ）的病因之一。然而，由于 DNMT1 过表达而导致失调的基因信息有限。为了测试是否有更多的与 SZ 相关的基因受到影响，我们选择了 15 个据报道在患者中失调的基因（Gad1、Reln、Ank3、Cacna1c、Dkk3、As3mt、Ppp1r11、Smad5、Syn1、Wnt1、Pdgfra、Gsk3b、Cxcl12、Tcf4 和 Fez1）。将这些基因的转录水平与过表达 DNMT1 的 Dnmt1（Tet/Tet）小鼠胚胎干细胞（ESC）衍生的神经元（R1，野生型）进行比较。在 Tet/Tet 神经元中，有 13 个基因的转录水平发生了显著改变，其中 11 个的失调模式与患者相似。在这些 11 个基因中，有 8 个在 Tet/Tet ESC 中也发生了显著改变，但只有 5 个的失调模式与神经元相似。在 ESC、类胚体和神经元之间进行的比较分析将 15 个基因分为四个不同的组，其中大多数显示出发育阶段特异性的失调模式。来自神经元的代表性亚硫酸氢盐测序数据没有显示出失调基因启动子 DNA 甲基化的任何改变。用多西环素处理 Tet/Tet ESC，消除了 DNMT1，仅使 4 个基因（Gad1、Dkk3、As3mt 和 Syn1）的失调方向发生逆转。这些结果表明：1. 增加的 DNMT1 影响了大多数研究中的转录本水平；2. 失调似乎与启动子甲基化无关；3. 增加的 DNMT1 水平的影响仅对研究的部分基因是可逆的；4. 增加的 DNMT1 水平可能会影响多个与精神分裂症相关的基因的转录本水平。
