Age-Related Macular Degeneration: Genetic Variations and Animal Model

老年性黄斑变性(AMD)在全球老年人群中造成不可逆转的中心性视力丧失。各种研究表明，AMD具有重要的遗传成分。目前的证据支持这样一种假设，即基因变异导致了疾病的易感性。2003年，我们招募了晚期AMD患者和年龄匹配、视网膜正常的对照组，从而启动了这一项目。到目前为止，已经登记了465人，收集了107例AMD组织病理学病例。我们继续分析澳大利亚蓝山眼研究项目的835个DNA样本和美国AREDS项目的534个DNA样本。我们比较了AMD和对照组候选基因中单核苷酸多态(SNPs)的等位基因频率，并通过体外和/或体内实验对这些SNPs的功能进行了研究。通过这种方法，我们已经确定了AMD的遗传危险因素，以及这些基因变异在疾病发病机制中的可能作用。基于从上述方法获得的信息，2007年产生了一个基因工程动物(RD8背景的CCL2/CX3CR1双重缺陷(DKO RD8)小鼠)作为AMD模型。 在2012财年，(1)我们与另外两个校外研究机构签署了额外的材料转移协议，并将活的DKO RD8小鼠转移到它们身上，用于协作研究机制和治疗方案；(2)我们继续研究DKO RD8小鼠的特征，发表了一篇3D光学相干断层扫描评估论文(与Nicholas Bazan博士合作)(周，等人)。EXP Eye Res 2011；93：636-648)；(3)我们评估了TSG-6重组蛋白(与Proackop博士合作)对视网膜病变的抗炎和抑制作用，并发表了一篇论文(Tuo，et al.神经炎症，2012；9：59)。目前，我们正在使用这个动物模型评估其他化合物，如PDGF-CC(与Li Xuri博士合作)、PEDF(与Becera博士合作)和STC-1(与Prock op博士继续合作)；(4)我们提供DKO RD8视网膜给合作者进行基因芯片研究(与项梦青博士合作)，并将microRNA参与AMD的研究(与王树生博士合作)；(5)使用石蜡包埋的存档幻灯片，我们研究了巨噬细胞极化在AMD中的作用并发表了我们的结果(曹，等)。Pathol Int 2011；61：528-)；(6)我们进行了一项药物基因组学研究(与Catherine Meyerle博士、Richard Rosen博士和Shree Kurup博士合作)，探讨了抗血管内皮生长因子治疗对AMD的疗效和患者的基因分型，目前该论文的手稿正在《分子视觉》杂志上审阅；(7)我们对TIMP3在AMD中的作用进行了大规模的SNP关联研究，并在EUJ Hum Genet上对该手稿进行了审阅；(8)我们发表了一篇关于AMD炎症遗传学的综述论文(Tuo等人)。Ocul Immunol Inflamm 2012；20：27-36)和一章关于氧化应激在DKO RD8小鼠中的作用(Tuo.第17章《视网膜和脉络膜疾病的研究》(Stratton，Hauswirth，Gardner，编辑)Humana出版社，2012年，第355-365页)。

Age-related macular degeneration (AMD) causes irreversible central visual loss in the aged population worldwide. Various studies suggest that AMD has a significant genetic component. Current evidence supports the hypothesis that gene variation creates a predisposition to the disease. In 2003, we initiated this project by recruiting advanced AMD patients and age-matched control individuals with normal retinas. Up to date, 465 individuals have been enrolled and 107 histopathological cases with AMD have been collected. We continue to analyz 835 DNA samples from the Blue Mountain Eye Study in Australia and 534 DNA samples from the AREDS project in USA. We have compared the allelic frequencies of single nucleotide polymorphisms (SNPs) within candidate genes between AMD and control subjects, followed by functional studies of these SNPs by in vitro and/or in vivo experiments. Through this approach, we have identified genetic risk factors of AMD and the possible roles of these gene variations in the pathogenesis of the disease. Based on the information obtained from the above approaches, a genetically engineered animal (Ccl2/Cx3cr1 double deficiencies on rd8 background (DKO rd8) mice) was generated to act as an AMD model in 2007. In FY2012, (1) we signed 2 additional material transfer agreements with 2 other extramural research institutes and transferred living DKO rd8 mice to them for collaborative studies of mechanisms and therapeutic options; (2) we continued characterizing DKO rd8 mice, a paper of 3D optical coherence tomography assessment (collaboration with Dr. Nicholas Bazan) was published (Zhou, et al. Exp Eye Res 2011;93:636-648); (3) we evaluated the anti-inflammatory and suppressive effect of TSG-6 recombinant protein (collaboration with Dr. Prockop) on the retinal lesions and published a paper (Tuo, et al. Neuroinflammation 2012;9:59). Currently, we are evaluating other compounds such as PDGF-CC (collaboration with Dr. Xuri Li), PEDF (collaboration with Dr. Becerra) and STC-1 (continue collaboration with Dr. Prockop) by using this animal model; (4) we provided DKO rd8 retina to collaborators for studies on microarray (collaboration with Dr. Mengqing Xiang and microRNA involvements in AMD (collaboration with Dr. Shusheng Wang); (5) using paraffin-embeded, archived slides, we studied the role of macrophage polarization in AMD and published our results (Cao, et al. Pathol Int 2011;61:528-535); (6) we conducted a pharmacogenomic study (collaboration with Drs. Catherine Meyerle, Richard Rosen and Shree Kurup) on the efficacy of anti-VEGF therapy on AMD and patients genotypes and currently have the manuscript under review in Molecular Vision; (7) we performed a large scale SNP association study on the role of TIMP3 in AMD and have the manuscript under review in Eur J Hum Genet; (8) we published a review paper on the genetics of inflammation in AMD (Tuo, et al. Ocul Immunol Inflamm 2012;20:27-36) and a chapter regarding the role of oxidative stress in DKO rd8 mice (Tuo. Chapt 17 in Studies on Retinal and Choroidal Disorders (Stratton, Hauswirth, Gardner, eds.) Humana Press, 2012, pp. 355-365).