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

光的检测发生在杆和锥光感受器的高度组织化的隔室中，称为外节。四跨膜蛋白家族成员外周蛋白-2是负责视杆细胞和视锥细胞外节结构完整性的糖膜蛋白。外周蛋白-2基因（PRPH 2）突变是退行性视网膜疾病的最常见原因之一，通常导致完全失明。这些突变中的大多数主要影响视杆细胞并导致常染色体显性视网膜色素变性（adRP）。相比之下，PRPH 2中的其他突变导致各种视锥细胞特异性疾病。到目前为止，这种在视杆细胞和视锥细胞中的单一突变的差异表达的分子机制仍然是未知的。PRPH 2基因突变多为外显子2的错义突变。在这个提议中，我们着手在转录本和蛋白质水平上表征外周蛋白2外显子2中疾病相关的错义突变的病理机制。因此，我们计划使用adRP的小鼠模型建立基于miRNA的基因治疗，以拯救感光细胞形态并预防视网膜变性。综上所述，我们的研究将有助于破译与外周蛋白-2相关的视网膜疾病的病理机制，并揭示外周蛋白-2在视杆细胞和视锥细胞中的差异功能。最后，我们的研究结果将提供一个实验平台，为临床研究治疗adRP。

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.