A murine model for human factor H R1210C mutation-related diseases

人类因子HR1210C突变相关疾病的小鼠模型

• 批准号: 8652434
• 负责人: Wenchao Song
• 金额: $ 20万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-16 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8652434
• 关键词: Affect; Affinity; Age related macular degeneration; Alternative Complement Pathway; Amino Acids; Animal Model; Arginine; Binding; Blood Proteins; C-terminal; Cattle; Cells; Complement; Complement 3b; Complement 3d; Complement Factor H; Cysteine; Defect; Deposition; Development; Dialysis procedure; Disease; Endothelial Cells; Family suidae; Figs - dietary; Gene Targeting; Genetic; Grant; Hemolytic-Uremic Syndrome; Heparin; Human; Human Factor H; In Vitro; Individual; Infection Control; Kidney Diseases; Knowledge; Light; Modeling; Mus; Mutagenesis; Mutant Strains Mice; Mutation; N-terminal; Pathogenesis; Pathology; Patients; Plasma; Positioning Attribute; Rattus; Retinal Degeneration; Risk; Structure; Surface; Sushi Domain; Testing; Tissues; Transplantation; Variant; human disease; inhibitor/antagonist; interest; mouse model; mutant; public health relevance

DESCRIPTION (provided by applicant): Factor H (fH) is a plasma inhibitor of the alternative pathway (AP) complement. It is composed of 20 short consensus repeat (SCR) domains. The complement regulatory function of fH is located in the N-terminal SCR1-4, whereas the two C-terminal SCRs of fH (SCR 19 and 20) are critical for interacting with surface deposited C3b/C3d in the context of host cell-specific polyanionic constituents. Mutations in SCR19-20 of human fH impair its interaction with host cells and predispose to the development of atypical hemolytic uremic syndrome (aHUS). Among the various SCR19-20 mutations of fH that are found in aHUS patients, the R1210C mutation is of particular interest as a recent genetic study has identified this mutation to be also a high-penetrant mutation for the development of age-related macular degeneration (AMD). The R1210C variant of human fH showed reduced binding to C3b/C3d, heparin and endothelial cells, yet R1210 is not conserved across species (D1210 in mouse, G1210 in rat, P1210 in cows and pigs). We hypothesize that the change of amino acid at position 1210 of human fH to cysteine, rather than the simple loss of arginine, is critical for conferring the risk of aHUS and AMD. In this exploratory grant, we propose two specific aims to test this hypothesis. Specific Aim 1. We will perform in vitro mutagenesis studies of human and mouse fH at residue 1210 and test the prediction that a mouse D1210C mutant will, like human R1210C mutant, have impaired binding to C3b, heparin and endothelial cells. On the other hand, we predict that mutations of R1210 in human fH to R1210D, R1210G and R1210P (to mouse, rat and cow/pig residue, respectively), and mutations of D1210 in mouse fH to D1210R, D1210G and D1210P (to human, rat, and cow/pig residue, respectively), are tolerated and produce no functional consequences for C3b-, heparin- and endothelial cell-binding. Specific Aim 2. We will generate by gene targeting a D1210C mutant mouse and determine if this mouse develops aHUS and/or retinal degeneration resembling human AMD. These studies will shed new light on structure/function knowledge of the fH C-terminal domain and establish how specific mutations in this domain may differentially affect fH function in different tissues and species. Furthermore, they will help us understand the pathogenesis of two fH-related human diseases and provide a much- needed mouse model for testing anti-complement therapies for these pathologies.

描述（由申请人提供）： H 因子 (fH) 是旁路途径 (AP) 补体的血浆抑制剂。它由 20 个短一致重复 (SCR) 域组成。 fH 的补体调节功能位于 N 端 SCR1-4，而 fH 的两个 C 端 SCR（SCR 19 和 20）对于在宿主细胞特异性聚阴离子成分的背景下与表面沉积的 C3b/C3d 相互作用至关重要。人类 fH 的 SCR19-20 突变会损害其与宿主细胞的相互作用，并导致非典型溶血性尿毒症综合征 (aHUS) 的发展。在 aHUS 患者中发现的各种 fH SCR19-20 突变中，R1210C 突变特别令人感兴趣，因为最近的一项基因研究已确定该突变也是年龄相关性黄斑变性 (AMD) 发展的高渗透突变。人fH的R1210C变体与C3b/C3d、肝素和内皮细胞的结合减少，但R1210在物种间并不保守（小鼠中的D1210、大鼠中的G1210、牛和猪中的P1210）。我们假设人类 fH 1210 位氨基酸改变为半胱氨酸，而不是简单的精氨酸丢失，对于 aHUS 和 AMD 的风险至关重要。在这项探索性资助中，我们提出了两个具体目标来检验这一假设。具体目标 1. 我们将对人和小鼠 fH 残基 1210 处进行体外诱变研究，并测试小鼠 D1210C 突变体将与人 R1210C 突变体一样，与 C3b、肝素和内皮细胞的结合受损的预测。另一方面，我们预测人fH中R1210突变为R1210D、R1210G和R1210P（分别突变为小鼠、大鼠和牛/猪残基），以及小鼠fH中D1210突变为D1210R、D1210G和D1210P（分别突变为人、大鼠和牛/猪残基），是可以耐受的并且不会产生功能性后果C3b-, 肝素和内皮细胞结合。具体目标 2. 我们将通过基因靶向生成 D1210C 突变小鼠，并确定该小鼠是否会出现类似于人类 AMD 的 aHUS 和/或视网膜变性。这些研究将为 fH C 末端结构域的结构/功能知识提供新的线索，并确定该结构域中的特定突变如何对不同组织和物种中的 fH 功能产生不同的影响。此外，它们将帮助我们了解两种与 fH 相关的人类疾病的发病机制，并提供急需的小鼠模型来测试这些疾病的抗补体疗法。