Mechanism-based therapies for photoreceptor degeneration

 描述（由申请人提供）：感光细胞变性和葡萄膜炎（眼内炎症）的分子靶点知之甚少。进展的一个主要障碍是缺乏任何特定的分子原因。这项建议建立在我们令人兴奋的发现钙激活CAPN 5（钙蛋白酶-5）作为常染色体显性遗传性新生血管炎性玻璃体视网膜病变（ADNIV）的原因。CAPN 5是第一个非综合征性葡萄膜炎基因，并使一个高度创新的分子遗传学方法成为可能，用于感光细胞变性诱导的炎症的基于机制的治疗。光感受器表达CAPN 5，并且小鼠中的hCAPN 5-R243 L功能突变的获得显示了人ADNIV疾病的所有表型。视网膜光感受器可能对CAPN 5的突变特别敏感，因为高细胞内钙对于调节光感受器的暗适应是必要的和足够的。我们的长期目标是找到更好，更具体的治疗感光细胞变性。我们的目标是使用我们的新hCAPN 5-R243 L小鼠来确定阻断CAPN 5活性是否可以抑制变性和葡萄膜炎。我们的中心假设是钙激活的CAPN 5途径导致ADNIV视网膜变性和葡萄膜炎，我们的转基因CAPN 5突变小鼠是测试几种新的葡萄膜炎疗法的最佳动物模型。我们的具体目标是（1）用药理学CAPN 5抑制剂治疗hCAPN 5-R243 L小鼠的光感受器变性，（2）用新型双链shRNA基因沉默载体拯救hCAPN 5-R243 L小鼠的光感受器表型，以及（3）使用市售的靶向IL-6和IL-23的中和抗体治疗hCAPN 5-R243 L小鼠的葡萄膜炎。冲击我们期望建立hCAPN 5-R243 L小鼠作为一种有价值的动物模型，用于测试ADNIV的新疗法，该疗法可以转化为患者。我们的工作将有助于确定钙激活的CAPN 5信号在ADNIV和其他感光细胞变性中的作用。由于hCAPN 5-R243 L疾病分期表型与其他形式的葡萄膜炎中发现的光感受器变性和CAPN 5途径的组分的其他眼病，我们的研究可能具有广泛的积极影响，超越ADNIV和葡萄膜炎患者，其中CAPN 5途径的组分可能是治疗靶点。

 DESCRIPTION (provided by applicant): The molecular targets for photoreceptor degenerations and uveitis (intraocular inflammation) are poorly understood. A major barrier to progress has been the lack of any specific molecular cause. This proposal builds on our exciting discovery of calcium-activated CAPN5 (calpain-5) as the cause of Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy (ADNIV). CAPN5 is the first nonsyndromic uveitis gene, and makes possible a highly innovative molecular-genetic approach for mechanism-based therapies for inflammation induced by photoreceptor degeneration. Photoreceptors express CAPN5, and an hCAPN5- R243L gain of function mutation in mice shows all the phenotypes of human ADNIV disease. The retina photoreceptors might be particularly sensitive to mutations in CAPN5, because high intracellular calcium is necessary and sufficient to regulate dark adaptation in photoreceptors. Our long-term goals are to find better and more specific treatments for photoreceptor degeneration. Our objective is to use our new hCAPN5-R243L mice to determine whether blocking CAPN5 activity can inhibit degeneration and uveitis. Our central hypothesis is that a calcium-activated CAPN5 pathway leads to ADNIV retinal degeneration and uveitis, and our transgenic CAPN5 mutant mouse is the best available animal model for testing several new uveitis therapies. Our specific aims are to (1) Treat photoreceptor degeneration in hCAPN5-R243L mice with a pharmacological CAPN5 inhibitor, (2) Rescue the photoreceptor phenotype in hCAPN5-R243L mice with a novel bipartite shRNA gene silencing vector, and (3) Treat uveitis in hCAPN5-R243L mice using commercially available neutralizing antibodies targeting IL-6 and IL-23. Impact. We expect to establish the hCAPN5-R243L mouse as a valuable animal model for testing novel therapies in ADNIV, which can be translated to patients. Our work should help determine the role of of calcium-activated CAPN5 signaling in ADNIV and other photoreceptor degenerations. Since hCAPN5-R243L disease stages phenocopy other eye diseases with photoreceptor degeneration and components of the CAPN5 pathway are found in other forms of uveitis, our studies could have a broad, positive impact, beyond ADNIV and uveitis patients, where components of the CAPN5 pathway may be therapeutic targets.