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: 8489610
• 负责人: Wenchao Song
• 金额: $ 24万
• 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/8489610
• 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（由申请方提供）：因子H（fH）是旁路途径（AP）补体的血浆抑制剂。它由20个短一致重复序列（SCR）结构域组成。fH的补体调节功能位于N-末端SCR 1 -4，而fH的两个C-末端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C3 b/C3 d相互作用至关重要。人fH的SCR 19 -20中的突变损害其与宿主细胞的相互作用，并使其易于发展为非典型溶血性尿毒综合征（阿胡斯）。在阿胡斯患者中发现的fH的各种SCR 19 -20突变中，R1210 C突变特别令人感兴趣，因为最近的遗传研究已经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R1210 C变体显示与C3 b/C3 d、肝素和内皮细胞的结合减少，但R1210在物种间不保守（小鼠中的D1210，大鼠中的G1210，牛和猪中的P1210）。我们推测人fH第1210位氨基酸变为半胱氨酸，而不是精氨酸的简单丢失，是阿胡斯和AMD风险的关键。在这个探索性的补助金，我们提出了两个具体的目标来测试这个假设。具体目标1。我们将在残基1210处对人和小鼠fH进行体外诱变研究，并测试小鼠D1210 C突变体与人R1210 C突变体一样与C3 b、肝素和内皮细胞结合受损的预测。另一方面，我们预测人fH中R1210突变为R1210 D、R1210 G和R1210 P，（分别针对小鼠、大鼠和牛/猪残留物），以及小鼠fH中D1210突变为D1210 R、D1210 G和D1210 P（分别对人、大鼠和牛/猪残留物）是耐受的，并且对C3 b-、肝素-和内皮细胞结合没有产生功能性后果。具体目标2。我们将通过基因靶向产生D1210 C突变小鼠，并确定该小鼠是否发生类似于人类AMD的阿胡斯和/或视网膜变性。这些研究将揭示fH C-末端结构域的结构/功能知识，并确定该结构域中的特定突变如何在不同组织和物种中差异地影响fH功能。此外，它们将帮助我们了解两种fH相关人类疾病的发病机制，并提供急需的小鼠模型用于测试针对这些病理的抗补体疗法。