Lipoprotein(a), or Lp(a), is encoded by the LPA gene and is a causal genetic risk factor for cardiovascular disease. Individuals with high Lp(a) are at risk for cardiovascular morbidity and are refractory to standard lipid-lowering agents. Lp(a)-lowering therapies currently in clinical development require repetitive dosing, while a gene editing approach presents an opportunity for a single-dose treatment. In this study, mRNAs encoding transcription activator-like effector nucleases (TALENs) were designed to target human LPA for gene disruption and permanent Lp(a) reduction. TALEN mRNAs were screened in vitro and found to cause on-target gene editing and target protein reduction with minimal off-target editing. TALEN mRNAs were then encapsulated with LUNAR, a proprietary lipid nanoparticle (LNP), and administered to transgenic mice that expressed a human LPA transgene. A single dose of TALEN mRNA-LNPs reduced plasma Lp(a) levels in mice by over 80%, which was sustained for at least 5 weeks. Moreover, both standard and long-read next-generation sequencing confirmed the presence of gene-inactivating deletions at LPA transgene loci. Overall, this study serves as a proof-of-concept for using TALEN-mediated gene editing to disrupt LPA in vivo, paving the way for the development of a feasible gene editing therapy for patients with high Lp(a).

中文翻译：

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靶向 LPA 的 TALEN mRNA 的脂质纳米颗粒递送导致转基因小鼠的基因破坏和血浆脂蛋白 （a） 减少


脂蛋白 （a） 或 Lp（a） 由 LPA 基因编码，是心血管疾病的致病遗传危险因素。Lp（a） 高的个体有发生心血管疾病的风险，并且对标准降脂药物无效。目前正在临床开发的降低 Lp（a） 疗法需要重复给药，而基因编辑方法为单剂量治疗提供了机会。在这项研究中，编码转录激活因子样效应核酸酶 （TALEN） 的 mRNA 被设计为靶向人 LPA 进行基因破坏和永久 Lp（a） 减少。在 体外筛选 TALEN mRNA，发现以最小的脱靶编辑引起靶向基因编辑和靶蛋白减少。然后用 LUNAR（一种专有脂质纳米颗粒 （LNP））封装 TALEN mRNA，并施用给表达人 LPA 转基因的转基因小鼠。单剂量的 TALEN mRNA-LNPs 使小鼠的血浆 Lp（a） 水平降低了 80% 以上，这种情况持续了至少 5 周。此外，标准和长读长下一代测序都证实了 LPA 转基因位点存在基因失活缺失。总体而言，本研究作为使用 TALEN 介导的基因编辑在体内破坏 LPA 的概念验证，为开发适用于高 Lp（a） 患者的可行基因编辑疗法铺平了道路。