Translational Epigenetics with XIST: Silencing Trisomy in Human Organoid and Mouse Models of Down Syndrome

摘要 这项研究的更广泛的视野是开发“转化表观遗传学”在很大程度上未开发的潜力 XIST RNA和先进的理解和唐氏综合症的潜在治疗策略。人类 XIST/小鼠Xist编码一种独特的长非编码RNA，其具有良好的诱导稳定表达的能力。 表观遗传沉默，顺式。虽然XIST RNA和X染色体剂量补偿的基本生物学是 经过大量研究，我们的实验室正在努力开拓XIST剂量补偿的转化潜力， 常见的染色体不平衡，尤其是唐氏综合症。染色体异常仍然是主要的， 人类遗传负担的未解决部分，发生在1/140的分娩中。这将是“改变游戏规则”，如果 在携带21三体的细胞中，数百个基因的过度表达可以通过操纵 一个基因XIST劳伦斯实验室最近在体外证明，一个大的XIST cDNA可以准确地表达。 插入一条21号染色体，并诱导令人惊讶的全面，稳定的“三体沉默”， 常染色体，显示在衍生自DS患者细胞的未分化iPS细胞中。我们现在寻求资金， 为追求下一个雄心勃勃的目标奠定了最近进展的坚实基础;测试和发展长期目标 体内三体沉默的潜在发展。为此，我们将研究XIST介导的 染色体沉默及其逆转或减轻细胞或生物病理学的能力，在人脑中 类器官和神经细胞，并在一个充分研究的三体小鼠模型的DS。除了与DS的相关性外， 我们的研究与阿尔茨海默病直接相关，阿尔茨海默病几乎不可避免地发生，并且在20-30年内 唐氏综合症患者通过将我们的一些目标集中在APP基因座上，我们将测试一些策略， APP靶向基因治疗是插入XIST转基因进行染色体治疗的第一步。我们有 组建了一个由共同研究者和合作者组成的多学科团队，由两名PI领导， 我们将共同测试策略，并探索XIST RNA提供多功能 唐氏综合症和其他潜在疾病的“转化表观遗传学”工具。

ABSTRACT The broader vision of this research is to develop the largely unexplored potential for “translational epigenetics” of XIST RNA and advance understanding and a potential therapeutic strategy for Down Syndrome. Human XIST/mouse Xist encodes a unique long non-coding RNA with the well-established power to induce stable epigenetic silencing, in cis. While the basic biology of XIST RNA and X-chromosome dosage compensation is heavily studied, our lab is working to pioneer the translational potential of XIST dosage compensation for common chromosomal imbalances, particularly Down Syndrome. Chromosomal abnormalities remain a major, unaddressed part of the human genetic burden, occurring in 1/140 births. It would be “game-changing” if the over-expression of hundreds of genes in cells carrying trisomy 21 could be addressed by manipulation of just one gene, XIST. The Lawrence lab recently demonstrated in vitro that a large XIST cDNA could be accurately inserted into one chromosome 21 and induce surprisingly comprehensive, stable “trisomy silencing” of the autosome, shown in undifferentiated iPS cells derived from DS patient cells. We now seek funding to build on a strong foundation of recent progress in pursuit of the next ambitious goal; to test and develop the longer-term potential development for trisomy silencing in vivo. To this end, we will investigate XIST-mediated chromosomal silencing and its ability to reverse or mitigate cell or organism pathology, in human cerebral organoid and neural cells and in a well-studied trisomic mouse model of DS. In addition to relevance for DS, our studies have direct relevance for Alzheimer Disease, which occurs almost inevitably and 20-30 years in individuals with Down Syndrome. By focusing some of our goals on the APP locus, we will test strategies that target gene therapy for APP as a first step to insertion of XIST transgenes for chromosome therapy. We have assembled a multi-disciplinary team of co-investigators and collaborators, led by two PIs with complementary expertise, and together we will test strategies and probe the full potential that XIST RNA provides a versatile tool for “translational epigenetics” for Down Syndrome and potentially other conditions.