Dnmt3b regulates DUX4 expression in a tissue-dependent manner in transgenic D4Z4 mice.
Dnmt3b regulates DUX4 expression in a tissue-dependent manner in transgenic D4Z4 mice.
复制标题
DOI：
10.1186/s13395-020-00247-0
复制
发表时间：
2020-10-01
期刊：
影响因子：
4.9
通讯作者：
de Greef JC
中科院分区：
文献类型：
--
作者：
Bouwman LF;den Hamer B;Verveer EP;Lerink LJS;Krom YD;van der Maarel SM;de Greef JC
面肩肱骨肌营养不良症（FSHD）是一种骨骼肌疾病，由骨骼肌细胞中转录因子DUX4的抑制引起。除SMCHD1外，DNMT3B最近被确定为FSHD的疾病基因和疾病修饰因子。然而，DNMT3B在D4Z4重复序列中的确切作用尚不清楚。为了确定Dnmt3b在DUX4抑制中的作用，将具有fshd大小的D4Z4重复序列的半合子小鼠（D4Z4-2.5小鼠）与携带Dnmt3b框内外显子跳变的小鼠（Dnmt3bMommeD14小鼠）杂交。此外，在D4Z4-2.5小鼠模型衍生的小鼠胚胎干细胞（mESCs）中进行了Dnmt3b的siRNA敲低。在来自D4Z4-2.5小鼠的mESCs中，Dnmt3b在D4Z4重复序列上富集，并且在敲低Dnmt3b后DUX4转录水平上调。在D4Z4-2.5/Dnmt3bMommeD14小鼠中，Dnmt3b蛋白水平降低；然而，骨骼肌中DUX4 RNA水平未升高，未观察到病理变化。有趣的是，D4Z4-2.5/Dnmt3bMommeD14小鼠显示D4Z4重复序列的DNA甲基化缺失，并且在次级淋巴器官中DUX4转录物水平显著升高。由于这些淋巴器官似乎对D4Z4重复序列的表观遗传修饰因子更敏感，因此我们对D4Z4-2.5小鼠与Dnmt3bMommeD14小鼠或Smchd1MommeD1小鼠杂交后脾脏和腹股沟淋巴结中的不同免疫细胞群进行了量化。只有D4Z4-2.5/Smchd1MommeD1小鼠的免疫细胞群受到干扰。我们的数据表明，Dnmt3b的缺失导致D4Z4-2.5/Dnmt3bMommeD14小鼠淋巴组织和mESCs中DUX4的下调，而在肌源性细胞中则没有。此外，Smchd1MommeD1变异体似乎在DUX4抑制中具有更有效的作用。我们的研究表明，免疫系统对D4Z4染色质修饰剂特别敏感，但存在差异，这可能为FSHD中尚未充分探索的免疫参与提供了分子基础。
Facioscapulohumeral muscular dystrophy (FSHD) is a skeletal muscle disorder that is caused by derepression of the transcription factor DUX4 in skeletal muscle cells. Apart from SMCHD1, DNMT3B was recently identified as a disease gene and disease modifier in FSHD. However, the exact role of DNMT3B at the D4Z4 repeat array remains unknown. To determine the role of Dnmt3b on DUX4 repression, hemizygous mice with a FSHD-sized D4Z4 repeat array (D4Z4-2.5 mice) were cross-bred with mice carrying an in-frame exon skipping mutation in Dnmt3b (Dnmt3bMommeD14 mice). Additionally, siRNA knockdowns of Dnmt3b were performed in mouse embryonic stem cells (mESCs) derived from the D4Z4-2.5 mouse model. In mESCs derived from D4Z4-2.5 mice, Dnmt3b was enriched at the D4Z4 repeat array and DUX4 transcript levels were upregulated after a knockdown of Dnmt3b. In D4Z4-2.5/Dnmt3bMommeD14 mice, Dnmt3b protein levels were reduced; however, DUX4 RNA levels in skeletal muscles were not enhanced and no pathology was observed. Interestingly, D4Z4-2.5/Dnmt3bMommeD14 mice showed a loss of DNA methylation at the D4Z4 repeat array and significantly higher DUX4 transcript levels in secondary lymphoid organs. As these lymphoid organs seem to be more sensitive to epigenetic modifiers of the D4Z4 repeat array, different immune cell populations were quantified in the spleen and inguinal lymph nodes of D4Z4-2.5 mice crossed with Dnmt3bMommeD14 mice or Smchd1MommeD1 mice. Only in D4Z4-2.5/Smchd1MommeD1 mice the immune cell populations were disturbed. Our data demonstrates that loss of Dnmt3b results in derepression of DUX4 in lymphoid tissues and mESCs but not in myogenic cells of D4Z4-2.5/Dnmt3bMommeD14 mice. In addition, the Smchd1MommeD1 variant seems to have a more potent role in DUX4 derepression. Our studies suggest that the immune system is particularly but differentially sensitive to D4Z4 chromatin modifiers which may provide a molecular basis for the yet underexplored immune involvement in FSHD.
登录
查看更多内容
影响因子：
3.7
作者：
Das S;Chadwick BP
通讯作者：
Chadwick BP
影响因子：
12.3
作者：
Daxinger L;Harten SK;Oey H;Epp T;Isbel L;Huang E;Whitelaw N;Apedaile A;Sorolla A;Yong J;Bharti V;Sutton J;Ashe A;Pang Z;Wallace N;Gerhardt DJ;Blewitt ME;Jeddeloh JA;Whitelaw E
通讯作者：
Whitelaw E
影响因子：
3.7
作者：
Jones T;Jones PL
通讯作者：
Jones PL
影响因子：
5.5
作者：
Gagliardi M;Strazzullo M;Matarazzo MR
通讯作者：
Matarazzo MR
影响因子：
64.5
作者：
Okano, M;Bell, DW;Li, E
通讯作者：
Li, E