Division of Gastroenterology, Washington University, St Louis School of Medicine, St Louis, Missouri, USA.
Inflamm Bowel Dis. 2010 Oct;16(10):1649-57. doi: 10.1002/ibd.21208.
NOD2 single nucleotide polymorphisms have been associated with increased risk of ileal Crohn's disease (CD). This exploratory study was conducted to compare ileal mucosal gene expression in CD patients with and without NOD2 risk alleles.
Ileal samples were prospectively collected from 18 nonsmoking CD patients not treated with anti-TNF-α biologics and 9 nonsmoking control patients without inflammatory bowel disease undergoing initial resection and genotyped for the 3 major NOD2 risk alleles (Arg702Trp, Gly908Arg, Leu1007fs). Microarray analysis was performed in samples from 4 NOD2(R) (at least 1 risk allele) CD patients, 4 NOD2(NR) (no risk alleles) CD patients, and 4 NOD2(NR) controls. Candidate genes selected by significance analysis of microarrays (SAM) were confirmed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assays of all the samples.
SAM detected upregulation of 18 genes in affected ileum in NOD2(R) compared to NOD2(NR) CD patients, including genes related to lymphocyte activation. SAM also detected altered ileal gene expression in unaffected NOD2(NR) ileal mucosal CD samples compared to NOD2(NR) control samples. qRT-PCR conducted on all the samples confirmed that increased CD3D expression in affected samples was associated with NOD2(R) status, and that increased MUC1, DUOX2, DMBT1 and decreased C4orf7 expression in unaffected samples was associated with CD, independent of NOD2 status.
The results support the concept that NOD2 risk alleles contribute to impaired regulation of inflammation in the ileum. Furthermore, altered ileal gene expression, independent of NOD2 status, is detected in the unaffected proximal margin of resected ileum from CD patients.
NOD2 单核苷酸多态性与回肠克罗恩病（CD）的风险增加相关。本探索性研究旨在比较 NOD2 风险等位基因的 CD 患者和无风险等位基因的 CD 患者回肠黏膜基因表达的差异。
前瞻性收集 18 例未接受抗 TNF-α 生物制剂治疗的非吸烟 CD 患者和 9 例非吸烟无炎症性肠病患者的回肠样本，这些患者接受了初次切除术并对 3 个主要的 NOD2 风险等位基因（Arg702Trp、Gly908Arg、Leu1007fs）进行了基因分型。对 4 例 NOD2(R)（至少有 1 个风险等位基因）CD 患者、4 例 NOD2(NR)（无风险等位基因）CD 患者和 4 例 NOD2(NR)对照者的样本进行了微阵列分析。通过微阵列分析的显著性分析（SAM）选择候选基因，并用所有样本的定量逆转录聚合酶链反应（qRT-PCR）进行验证。
SAM 检测到 NOD2(R)CD 患者的回肠组织中 18 个基因的上调，包括与淋巴细胞激活相关的基因。SAM 还检测到无病变的 NOD2(NR)CD 患者的回肠黏膜组织中回肠基因表达的改变。对所有样本进行 qRT-PCR 证实，受影响样本中 CD3D 表达的增加与 NOD2(R)状态相关，而不受影响样本中 MUC1、DUOX2、DMBT1 的表达增加和 C4orf7 的表达减少与 CD 相关，与 NOD2 状态无关。
这些结果支持 NOD2 风险等位基因导致回肠炎症调节受损的概念。此外，在 CD 患者的切除回肠近端不受影响的边缘中，检测到独立于 NOD2 状态的改变的回肠基因表达。
