Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA.
Sci Signal. 2013 Jan 15;6(258):rs3. doi: 10.1126/scisignal.2003305.
The cytoplasmic receptor NOD2 (nucleotide-binding oligomerization domain 2) senses peptidoglycan fragments and triggers host defense pathways, including activation of nuclear factor κB (NF-κB) signaling, which lead to inflammatory immune responses. Dysregulation of NOD2 signaling is associated with inflammatory diseases, such as Crohn's disease and Blau syndrome. We used a genome-wide small interfering RNA screen to identify regulators of the NOD2 signaling pathway. Several genes associated with Crohn's disease risk were identified in the screen. A comparison of candidates from this screen with other "omics" data sets revealed interconnected networks of genes implicated in NF-κB signaling, thus supporting a role for NOD2 and NF-κB pathways in the pathogenesis of Crohn's disease. Many of these regulators were validated in secondary assays, such as measurement of interleukin-8 secretion, which is partially dependent on NF-κB. Knockdown of putative regulators in human embryonic kidney 293 cells followed by stimulation with tumor necrosis factor-α revealed that most of the genes identified were general regulators of NF-κB signaling. Overall, the genes identified here provide a resource to facilitate the elucidation of the molecular mechanisms that regulate NOD2- and NF-κB-mediated inflammation.
细胞质受体 NOD2（核苷酸结合寡聚结构域 2）可感知肽聚糖片段并触发宿主防御途径，包括核因子 κB（NF-κB）信号的激活，从而导致炎症免疫反应。NOD2 信号的失调与炎症性疾病有关，如克罗恩病和 Blau 综合征。我们使用全基因组小干扰 RNA 筛选来鉴定 NOD2 信号通路的调节剂。该筛选中鉴定出了与克罗恩病风险相关的几个基因。对该筛选中的候选基因与其他“组学”数据集的比较揭示了与 NF-κB 信号相关的基因的相互关联网络，从而支持 NOD2 和 NF-κB 途径在克罗恩病发病机制中的作用。这些调节剂中的许多在二次测定中得到了验证，例如部分依赖于 NF-κB 的白细胞介素-8 分泌的测量。在肿瘤坏死因子-α刺激后，对人胚肾 293 细胞中的假定调节剂进行敲低，结果表明，鉴定出的大多数基因都是 NF-κB 信号的一般调节剂。总的来说，这里鉴定的基因为阐明调节 NOD2 和 NF-κB 介导的炎症的分子机制提供了资源。
