Preclinical Development of Treatments for OPA1-linked Optic Neuropathies

OPA1连锁视神经病变(OPON)是一组遗传性神经退行性疾病，包括孤立性视神经萎缩(ADOA)，以及伴随各种眼外症状的综合征，如ADOAplus或Behr综合征。OPON是由OPA1突变引起的，OPA1是动力蛋白家族的一个核编码的线粒体大GTP酶，在线粒体动力学和眉骨连接维持中发挥核心作用。进行性视力丧失是这些患者最常见的症状，由功能障碍引起，最终导致视网膜神经节细胞及其形成视神经的轴突丢失。由于单倍体不足是OPONS的主要疾病机制，我们建议进一步开发和验证几种创新的治疗方法，这些方法要么普遍提高OPA1的表达(人工转录因子和AON阻断上游μORF翻译)，要么特异性地挽救突变的OPA1等位基因或转录本(反式剪接、基于U1/U6的剪接纠正和gRNA/dCas9介导的隐蔽外显子消除)。这些治疗方法基于前期工作，克服了目前针对OPA1的补充基因治疗的局限性。该项目的一个中心目标是使用共同的体外和体内模型资源，定义和实施在所有团队中应用的共同结果衡量标准，以及在小鼠模型中直接比较不同治疗方法的有效性的试点研究。

OPA1-linked Optic Neuropathies (OPONs) represent a group of inherited neurodegenerative disorders including isolated optic atrophy (adOA) as well as syndromic disease such as adOAplus or Behr syndrome with a variety of additional extraocular symptoms. OPONs are caused by mutations in OPA1, a nuclear encoded mitochondrial large GTPase of the dynamin family that plays a central role in mitochondrial dynamics and cristae junction maintenance. Progressive visual loss is the most common symptom in these patients resulting from a dysfunction and eventually loss of retinal ganglion cells and their axons forming the optic nerve. Since haploinsufficiency is the predominant disease mechanisms in OPONs we here propose to further develop and validate several innovative therapeutic approaches which either generally elevate OPA1 expression (artificial transcription factors and AONs blocking upstream μORF translation) or specifically rescue mutant OPA1 alleles or transcripts (trans-splicing, U1/U6-based splice correction, and gRNA/dCas9-mediated cryptic exon elimination). These therapeutic approaches are based on preliminary work and overcome current limitations of supplementation gene therapy for OPA1. A central objective of this project is the use of a common resource of established in vitro and in vivo models, the definition and implementation of common outcome measures applied in all teams and a pilot study on a direct comparison of the efficacy of different therapeutic approaches in the mouse model.