In vivo Analysis of Disease-Linked Mutations in Peripherin-2: Characterization of Pathomechanisms and Development of a miRNA-Based Gene Therapy for Autosomal Dominant Retinitis Pigmentosa

光的探测发生在杆状和锥状光感受器的高度组织的区室，称为外节。四跨蛋白家族成员外周蛋白-2是一种糖膜蛋白，负责杆状和锥体外段的结构完整性。外周蛋白-2基因（PRPH2）的突变是导致视网膜退行性疾病的最常见原因之一，这种疾病经常导致完全失明。这些突变主要影响视杆光感受器，并导致常染色体显性视网膜色素变性（adRP）。相比之下，PRPH2的其他突变导致各种锥体特异性疾病。到目前为止，杆状细胞和锥状细胞中单个突变的差异外显率的分子机制尚不清楚。PRPH2的大多数突变是位于外显子2的错义突变。在这个提议中，我们开始在转录和蛋白质水平上表征外显子2中疾病相关的错义突变的病理机制。随后，利用小鼠adRP模型，我们计划建立一种基于miRNA的基因治疗，以挽救光感受器形态并防止视网膜变性。总之，我们的研究将有助于破译外周蛋白-2相关视网膜疾病的病理机制，揭示外周蛋白-2在视杆细胞和视锥细胞中的不同功能。最后，我们的研究结果将为adRP治疗的临床研究提供实验平台。

Detection of light takes place in highly organized compartments of rod and cone photoreceptors called outer segments. The tetraspanin family member peripherin-2 is a glycomembrane-protein responsible for the structural integrity of rod and cone outer segments. Mutations in the peripherin-2 gene (PRPH2) are among the most common causes of degenerative retinal disorders which often lead to complete blindness. The majority of these mutations primary affects rod photoreceptors and results in autosomal dominant retinitis pigmentosa (adRP). By contrast, other mutations in PRPH2 lead to various cone specific diseases. So far the molecular mechanisms underlying this differential penetrance of single mutations in rods and cones remain unknown. Most of mutations in PRPH2 are missense-mutations located in exon 2. In this proposal we set out to characterize the pathomechanisms of disease-associated missense-mutations in exon 2 of peripherin-2 at the transcript and protein level. Consecutively, using a mouse model for adRP we plan to establish a miRNA based gene therapy to rescue the photoreceptor morphology and to prevent retinal degeneration. In summary, our study will help to decipher the pathomechanisms of peripherin-2 linked retinal disorders and to unveil the differential function of peripherin-2 in rods and cones. Finally, our results will provide an experimental platform for clinical studies on treatment of adRP.