Prader-Willi syndrome (PWS) is characterized by neonatal hypotonia, developmental delay, and hyperphagia/obesity. This disorder is caused by the absence of paternally-expressed gene products from chromosome 15q11-q13. We previously demonstrated that knocking out ZNF274, a KRAB-domain zinc finger protein capable of recruiting epigenetic machinery to deposit the H3K9me3 repressive histone modification, can activate expression from the normally silent maternal allele of SNORD116 in neurons derived from PWS iPSCs. However, ZNF274 has many other targets in the genome in addition to SNORD116. Depleting ZNF274 will surely affect the expression of other important genes and disrupt other pathways. Here we used CRISPR/Cas9 to delete ZNF274 binding sites at the SNORD116 locus to determine whether activation of the maternal copy of SNORD116 could be achieved without altering ZNF274 protein levels. We obtained similar activation of gene expression from the normally silenced maternal allele in neurons derived from PWS iPSCs, compared to ZNF274 knockout, demonstrating that ZNF274 is directly involved in the repression of SNORD116. These results suggest that interfering with ZNF274 binding at the maternal SNORD116 locus is a potential therapeutic strategy for PWS.

中文翻译：

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SNORD116 上的特定 ZNF274 结合干扰激活了 Prader-Willi 综合征神经元中的母体转录本。

Prader-Willi 综合征 (PWS) 的特征是新生儿肌张力低下、发育迟缓和食欲过盛/肥胖。这种疾病是由于缺乏来自染色体 15q11-q13 的父本表达的基因产物引起的。我们之前证明，敲除 ZNF274（一种 KRAB 域锌指蛋白，能够招募表观遗传机制以沉积 H3K9me3 抑制性组蛋白修饰）可以激活源自 PWS iPSC 的神经元中SNORD116的正常沉默母体等位基因的表达。然而，除了SNORD116之外，ZNF274在基因组中还有许多其他目标。消耗ZNF274肯定会影响其他重要基因的表达并破坏其他途径。在这里，我们使用 CRISPR/Cas9 删除 SNORD116 处的ZNF274结合位点基因座来确定是否可以在不改变 ZNF274 蛋白水平的情况下实现SNORD116母体拷贝的激活。与 ZNF274 敲除相比，我们从 PWS iPSC 衍生的神经元中正常沉默的母体等位基因中获得了类似的基因表达激活，这表明 ZNF274 直接参与了SNORD116的抑制。这些结果表明，在母体SNORD116位点干扰 ZNF274 结合是 PWS 的潜在治疗策略。