CAPN5-PDGF Signaling in Vitreoretinopathy

玻璃体视网膜病变中的 CAPN5-PDGF 信号转导

• 批准号: 9891062
• 负责人: Kellie A Schaefer
• 金额: $ 2.46万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-06 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9891062
• 关键词: Age; Automobile Driving; Blindness; Calcium; Calpain; Cell Culture Techniques; Cells; Cellular Assay; Cleaved cell; Clinical; Dark Adaptation; Degenerative Disorder; Dependence; Diabetic Retinopathy; Disease; Enzymes; Eye diseases; Family Study; Genes; Goals; Human; Hyperactive behavior; In Vitro; Inflammation; Inflammatory; Inherited; Link; Medicine; Molecular; Molecular Genetics; Molecular Target; Morbidity - disease rate; Mus; Mutation; Outcome Study; Pathogenesis; Pathology; Pathway interactions; Patients; Peptide Hydrolases; Phenocopy; Phenotype; Photoreceptors; Platelet-Derived Growth Factor; Platelet-Derived Growth Factor B; Play; Process; Protease Domain; Protein Fragment; Proteins; Proteolysis; Research; Retina; Retinal Degeneration; Retinal Photoreceptors; Role; Signal Transduction; Site; Testing; Transgenic Mice; Transgenic Organisms; Uveitis; Visual; Work; base; disease phenotype; experimental study; gain of function mutation; gene discovery; genetic approach; in vivo; innovation; insight; kindred; member; mouse model; mutant; neovascular; new therapeutic target; novel therapeutic intervention; overexpression; photoreceptor degeneration; pre-clinical; public health relevance; receptor; therapeutic target; therapy design

 DESCRIPTION (provided by applicant): The molecular targets for vitreoretinopathy and uveitis (intraocular inflammation) are poorly understood. This proposal builds on our exciting discovery of a calcium-activated protease, CAPN5 (calpain-5), as the cause of Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy (ADNIV), and that CAPN5 processes PDGFB signaling. 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 inflammatory vitreoretinopathy. Our objective is to use in vitro and in vivo cell culture and mouse models to determine the mechanisms responsible for controlling activity of CAPN5. We will also investigate how uncontrolled CAPN5 activity leads to aberrant signaling of one of its substrates, platelet-derived growth factor B (PDGFB), and how this signaling results in the subsequent ADNIV phenotypes. Our central hypothesis is that an uncontrolled, calcium-activated CAPN5 pathway leads to ADNIV retinal degeneration and uveitis through aberrant PDGFB signaling. By creating a new mouse model we will be able to identify new therapeutic targets. Our specific aims are to (1) Dissect the ADNIV CAPN5 autoproteolysis effect in cells, (2) Determine if ADNIV CAPN5 hyperactively cleaves PDGFB to upregulate signaling, and (3) Test if PDGFB loss rescues the ADNIV phenotype in a preclinical mouse model. Impact. We expect to gain not only a better understanding of calpain activity and the role PDGFB plays in eye disease, but also to identify new therapeutic targets that may be applicable to many eye diseases. Our work should help determine the role of PDGFB signaling in ADNIV and other vitreoretinal degenerative diseases.

 描述（由申请人提供）：对玻璃体视网膜病变和葡萄膜炎（眼内炎症）的分子靶点知之甚少。该提议建立在我们令人兴奋的发现钙激活蛋白酶CAPN 5（calpain-5）作为常染色体显性新生血管炎性玻璃体视网膜病变（ADNIV）的原因，并且CAPN 5处理PDGFB信号传导的基础上。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和更具体的治疗炎症性玻璃体视网膜病变。我们的目标是使用体外和体内细胞培养和小鼠模型来确定负责控制CAPN 5活性的机制。我们还将研究不受控制的CAPN 5活性如何导致其底物之一血小板衍生生长因子B（PDGFB）的异常信号传导，以及这种信号传导如何导致随后的ADNIV表型。我们的中心假设是不受控制的钙激活CAPN 5通路通过异常PDGFB信号传导导致ADNIV视网膜变性和葡萄膜炎。通过创建新的小鼠模型，我们将能够确定新的治疗靶点。我们的具体目标是（1）剖析细胞中ADNIV CAPN 5的自蛋白水解作用，（2）确定ADNIV CAPN 5是否过度切割PDGFB以上调信号传导，以及（3）在临床前小鼠模型中测试PDGFB缺失是否挽救了ADNIV表型。冲击我们希望不仅能更好地了解钙蛋白酶活性和PDGFB在眼科疾病中的作用，而且还能确定可能适用于许多眼科疾病的新治疗靶点。我们的工作将有助于确定PDGFB信号在ADNIV和其他玻璃体视网膜退行性疾病中的作用。