Division of Colon and Rectal Surgery, Department of Surgery, Pennsylvania State University College of Medicine, H137, 500 University Drive, Hershey, PA 17033, USA.
Dig Dis Sci. 2013 Sep;58(9):2599-607. doi: 10.1007/s10620-013-2696-8. Epub 2013 May 26.
Genetic and functional studies have associated variants in the NOD2/CARD15 gene with Crohn's disease.
This study aims to replicate the association of three common NOD2 mutations with Crohn's disease, study its effect on NOD2 expression in B cells and its interaction with other IBD-associated genes.
A total of 294 IBD patients (179 familial IBD, 115 sporadic IBD) and 298 unrelated healthy controls were from central Pennsylvania. NOD2 mutations were analyzed by primer-specific amplification, PCR based-RFLP, and validated with the ABI SNPlexM genotyping system. Gene-gene interaction was studied using a statistical model for epistasis analysis.
Three common NOD2 mutations are associated with Crohn's disease (p=5.08×10(-7), 1.67×10(-6), and 1.87×10(-2) for 1007fs, R720W, and G908R, respectively), but not with ulcerative colitis (p=0.1046, 0.1269, and 0.8929, respectively). For IBD overall, 1007finsC (p=4.4×10(-5)) and R720W (p=9.24×10(-5)) were associated with IBD, but not G908R (p=0.1198). We revealed significant interactions of NOD2 with other IBD susceptibility genes IL23R, DLG5, and OCTN1. We discovered that NOD2 was expressed in both normal human peripheral blood B cells and in EBV-transformed B cell lines. Moreover, we further demonstrated that muramyl dipeptide (MDP) stimulation of B lymphocytes up-regulated expression of NF-κB-p50 mRNA.
NOD2 is expressed in peripheral B cells, and the up-regulation of NOD2 expression by MDP was significantly impaired by NOD2 mutations. The finding suggests a possible role of NOD2 in the immunological response in IBD pathogenesis.
遗传和功能研究将 NOD2/CARD15 基因的变异与克罗恩病联系起来。
本研究旨在复制三种常见的 NOD2 突变与克罗恩病的关联，研究其对 B 细胞中 NOD2 表达的影响及其与其他 IBD 相关基因的相互作用。
共纳入 294 例 IBD 患者（179 例家族性 IBD，115 例散发性 IBD）和 298 例无关健康对照者，均来自宾夕法尼亚州中部。通过引物特异性扩增、基于 PCR 的 RFLP 以及 ABI SNPlexM 基因分型系统进行 NOD2 突变分析。使用互作分析的统计模型研究基因-基因相互作用。
三种常见的 NOD2 突变与克罗恩病相关（1007fs、R720W 和 G908R 的 p 值分别为 5.08×10(-7)、1.67×10(-6)和 1.87×10(-2)），但与溃疡性结肠炎无关（p 值分别为 0.1046、0.1269 和 0.8929）。对于 IBD 总体，1007finsC（p=4.4×10(-5)）和 R720W（p=9.24×10(-5)）与 IBD 相关，但 G908R 无关（p=0.1198）。我们揭示了 NOD2 与其他 IBD 易感性基因 IL23R、DLG5 和 OCTN1 的显著相互作用。我们发现 NOD2 在正常人外周血 B 细胞和 EBV 转化的 B 细胞系中均有表达。此外，我们进一步证明 MDP 刺激 B 淋巴细胞可上调 NF-κB-p50 mRNA 的表达。
NOD2 在周围 B 细胞中表达，MDP 刺激后 NOD2 表达的上调被 NOD2 突变显著抑制。这一发现提示 NOD2 可能在 IBD 发病机制中的免疫反应中发挥作用。
