Gene Therapy in Hutchinson-Gilford Progeria Syndrome

项目概要和摘要 Hutchinson-Gilford早衰综合征（HGPS）是一种涉及点突变的无法治愈的致命疾病 一种叫做核纤层蛋白A（LMNA）的基因。儿童通常在出生后两年内出现HGPS的迹象， 死亡的中位年龄为14岁，最常见于进行性动脉粥样硬化性心血管疾病。虽然 HGPS的致病突变是在18年前发现的，但目前还没有治愈这种疾病的方法。可编程基 DNA编辑现在使以前前所未有的改变DNA中单个核苷酸并纠正的能力成为可能 DNA链断裂的致病性突变。HGPS代表了一种易于测试碱基编辑的疾病， 然而，这种策略是否会改善与以下疾病相关的疾病表型仍然完全未知： HGPS因此，迫切需要研究DNA碱基编辑如何改变驱动HGPS的分子缺陷 以确定这种基因组疗法是否能够实现其治愈疾病的承诺。我们的整体目标 在该建议中，开发了腺嘌呤碱基编辑（ABE）作为HGPS治疗策略。我们的核心假设 成年小鼠的ABE治疗可以通过以下方式在动脉瘤中实现足够的编辑以逆转血管病理学： 细胞自主性对VSMCs存活和克隆增殖的影响。我们的假设是基于 新发表的和新的初步数据表明：1）致病突变的无瘢痕校正 通过ABE在患者成纤维细胞和HGPS的人源化小鼠模型中的作用; 2）预防血管病理学 在幼年小鼠ABE治疗后6个月，VSMCs的恢复; 3）总体上， ABE处理的幼龄动物的存活率。该项目的基本原理是， 以确定它们在治疗系统性人类疾病中的潜力。为了实现我们的目标，我们将 追求以下两个具体目标：1）测试DNA编辑是否改善了已建立的血管病理学。 通过用AAV-ABE的单次注射治疗不同年龄的成年HGPS动物来治疗疾病; 2）鉴定HGPS动物的免疫原性; ABE治疗后促进VSMC恢复的机制。这项工作的总体贡献将是 阐明腺嘌呤DNA碱基编辑如何改善HGPS的表型。该提案的核心创新之处在于 是HGP治疗的概念转变，其重点是纠正潜在的致病性 细胞和组织中的突变。

Project Summary and Abstract Hutchinson-Gilford Progeria Syndrome (HGPS) is an incurable, uniformly fatal disease involving a point mutation in a gene called Lamin A (LMNA). Children develop signs of HGPS typically within the two years after birth and die at a median age of 14, most commonly from progressive atherosclerotic cardiovascular disease. Although the causal mutation in HGPS was identified 18 years ago, no cures for this disease exist. Programmable base editing of DNA now enables the previously unprecedented ability to change single nucleotides in DNA and correct pathogenic mutations with DNA strand breaks. HGPS represents a tractable disease to test base editing, however it remains completely unknown whether this strategy will improve disease phenotypes associated with HGPS. As such, there is a critical need to study how DNA base editing alters the molecular defects driving HGPS in order to determine whether this genome therapy can fulfill its promise to cure disease. Our overall objective in this proposal is develop adenine base editing (ABE) as a treatment strategy for HGPS. Our central hypothesis is that ABE-treatment of adult mice can achieve sufficient editing in aortas to reverse vascular pathology through cell-autonomous effects on survival and clonal proliferation in VSMCs. Our hypothesis is formulated based on newly published and new preliminary data that demonstrate: 1) scarless correction of the pathogenic mutation by ABE in patient fibroblasts and in a humanized mouse model of HGPS; 2) prevention of vascular pathology and recovery of VSMCs at 6 months after ABE treatment of juvenile mice; 3) a significant increase in overall survival of ABE-treated juvenile animals. The rationale for this project is that validation of base editing therapies is needed to determine their potential in treating systemic human diseases. To attain our objectives, we will pursue the following two specific aims: 1) Test whether DNA editing improves vascular pathology in established disease by treating adult HGPS animals at different ages with a single injection of AAV-ABE; 2) Identify the mechanism(s) promoting VSMC recovery after ABE treatment. The overall contribution of this work will be to elucidate how adenine DNA base editing improves phenotypes in HGPS. The central innovation of this proposal is a conceptual shift in therapeutic treatment of HGPs by focusing on correcting the underlying pathogenic mutation in cells and tissues.