Regulation of Inflammation by IL1RN polymorphisms

摘要 有重要文献表明 IL1RN 多态性影响多种疾病的临床结果， 包括骨关节炎、糖尿病、幼年关节炎和肥胖症。传递 IL1RN 的精确机制 影响未知。我们已经证明 IL1RN TTG 单倍型（rs419598、rs315952 和 rs9005）预测 与年龄相关的放射线严重程度 [Kellgren-Lawrence 分级 (KL)、内侧关节间隙宽度 (JSW)] 和 与发生膝关节 OA 的风险增加 3 倍相关。此外，这种促炎基因型并不 仅限于 OA，但可以在类风湿性关节炎 (RA) 患者和肥胖患者中得到证实 IL1RN TTG 风险单倍型。 IL1RN基因中有多个功能元件，目前尚不清楚 其中哪一个通过调节 IL1RN 表达和影响其他因素来增强炎症功能 单倍型块中的基因。因此，这笔赠款的中心目标将是确定该项目的影响 使用转基因技术在体外和体内产生 IL1RN 风险单倍型。目标 1：使用合成人类 单倍型以确定哪些功能元件对于炎症表型至关重要 IL1RN 风险单倍型，体外。我们将在侧翼的背景下构建风险和保护性单倍型 人类基因使用“Assemblon”技术，可以构建和精确传递哺乳动物的基因 长度可达 200 kb 的基因位点。利用这项技术，我们将选择信息丰富的小鼠胚胎干细胞 (mESC) 系，并将在体外分化为单核细胞和巨噬细胞，并对其进行分析 IL1RN 和单倍型块中其他基因的表达、细胞因子的产生、表面标记 表达式。目标 2：生成表达 IL1RN TTG-2 风险或 TTG-0 非风险的人源化小鼠 用于研究手术诱导的 OA 内侧半月板 (DMM) 模型不稳定的单倍型。自从 最近的研究还表明 IL1RN 基因多态性与肥胖和胰岛素抵抗之间存在关联，我们 将在转基因人源化小鼠中研究高脂肪饮食诱导的肥胖模型。这些研究将阐明新颖的 IL1RN 风险单倍型影响细胞反应和炎症基因调控的机制， 并将揭示以前未被识别的各种功能相关基因，这些基因对于炎症至关重要 风险单倍型的功能。

ABSTRACT There is significant literature that IL1RN polymorphisms affect clinical outcomes in a variety of diseases, including osteoarthritis, diabetes, juvenile arthritis and obesity. The precise mechanisms that impart IL1RN's effects are unknown. We have shown that the IL1RN TTG haplotype (rs419598, rs315952 and rs9005) predicts both age-related radiographic severity [Kellgren-Lawrence grade (KL), medial joint-space width (JSW)] and is associated with a 3-fold increased risk for incident knee OA. Moreover, this pro-inflammatory genotype is not limited to OA but can be demonstrated in patients with rheumatoid arthritis (RA) and in obese patients who carry the IL1RN TTG risk haplotype. There are a number of functional elements in the IL1RN gene, and it is unclear which of these confers increased inflammatory function by modulating IL1RN expression and influencing other genes in the haplotype block. The central objective of this grant, therefore, will be to define the effects of the IL1RN risk haplotypes in vitro and in vivo using transgenic technologies. In Aim 1: Use synthetic human haplotypes to determine which functional elements are critical for the inflammatory phenotype conferred by the IL1RN risk haplotype, in vitro. We will construct risk and protective haplotypes in the context of the flanking human genes using “Assemblon” technology, which allows the construction and precision delivery of mammalian gene loci of up to 200 kb in length. Using this technology, we will select informative mouse embryonic stem cell (mESC) lines and will be differentiated in vitro to monocytes and macrophages which will be assayed for expression of IL1RN and the other genes in the haplotype block, cytokine production, surface marker expressions. Aim 2: Generate a humanized mouse expressing the IL1RN TTG-2 risk or TTG-0 non-risk haplotypes for study in the surgically induced destabilization of the medial meniscus (DMM) model of OA. Since recent studies also indicate an association of IL1RN genetic polymorphism in obesity and insulin resistance, we will study high-fat diet-induced obesity models in transgenic humanized mice. These studies will elucidate novel mechanisms by which the IL1RN risk haplotype influences cellular responses and inflammatory gene regulation, and will reveal previously unrecognized various functional linked genes, which are crucial for the inflammatory function of the risk haplotype.