Whittaker Danielle E, Riegman Kimberley L H, Kasah Sahrunizam, Mohan Conor, Yu Tian, Pijuan-Sala Blanca, Hebaishi Husam, Caruso Angela, Marques Ana Claudia, Michetti Caterina, Smachetti María Eugenia Sanz, Shah Apar, Sabbioni Mara, Kulhanci Omer, Tee Wee-Wei, Reinberg Danny, Scattoni Maria Luisa, Volk Holger, McGonnell Imelda, Wardle Fiona C, Fernandes Cathy, Basson M Albert
J Clin Invest. 2017 Mar 1;127(3):874-887. doi: 10.1172/JCI83408. Epub 2017 Feb 6.
The mechanisms underlying the neurodevelopmental deficits associated with CHARGE syndrome, which include cerebellar hypoplasia, developmental delay, coordination problems, and autistic features, have not been identified. CHARGE syndrome has been associated with mutations in the gene encoding the ATP-dependent chromatin remodeler CHD7. CHD7 is expressed in neural stem and progenitor cells, but its role in neurogenesis during brain development remains unknown. Here we have shown that deletion of Chd7 from cerebellar granule cell progenitors (GCps) results in reduced GCp proliferation, cerebellar hypoplasia, developmental delay, and motor deficits in mice. Genome-wide expression profiling revealed downregulated expression of the gene encoding the glycoprotein reelin (Reln) in Chd7-deficient GCps. Recessive RELN mutations have been associated with severe cerebellar hypoplasia in humans. We found molecular and genetic evidence that reductions in Reln expression contribute to GCp proliferative defects and cerebellar hypoplasia in GCp-specific Chd7 mouse mutants. Finally, we showed that CHD7 is necessary for maintaining an open, accessible chromatin state at the Reln locus. Taken together, this study shows that Reln gene expression is regulated by chromatin remodeling, identifies CHD7 as a previously unrecognized upstream regulator of Reln, and provides direct in vivo evidence that a mammalian CHD protein can control brain development by modulating chromatin accessibility in neuronal progenitors.
与CHARGE综合征相关的神经发育缺陷,包括小脑发育不全、发育迟缓、协调问题和自闭症特征,其潜在机制尚未明确。CHARGE综合征与编码ATP依赖型染色质重塑因子CHD7的基因突变有关。CHD7在神经干细胞和祖细胞中表达,但其在大脑发育过程中神经发生中的作用仍不清楚。在此,我们表明从小脑颗粒细胞祖细胞(GCp)中删除Chd7会导致小鼠GCp增殖减少、小脑发育不全、发育迟缓和运动缺陷。全基因组表达谱分析显示,Chd7缺陷型GCp中编码糖蛋白Reelin(Reln)的基因表达下调。隐性Reln突变与人类严重的小脑发育不全有关。我们发现分子和遗传证据表明,Reln表达降低导致GCp特异性Chd7小鼠突变体中的GCp增殖缺陷和小脑发育不全。最后,我们表明CHD7对于维持Reln基因座处开放、可及的染色质状态是必需的。综上所述,本研究表明Reln基因表达受染色质重塑调控,将CHD7鉴定为Reln先前未被认识的上游调节因子,并提供了直接的体内证据,证明哺乳动物的CHD蛋白可通过调节神经元祖细胞中的染色质可及性来控制大脑发育。