NFkB Signaling in Macrophages

摘要 巨噬细胞对病原体或组织损伤的炎症信号是 感染性和非感染性疾病的病理学和发病机制。转录因子NFκB控制 炎症性基因表达程序，但尚不清楚其调控如何决定健康或 疾病相关基因表达反应。 在上一次资助期间，我们使用了实验/计算相结合的模型 一种预测性地了解核因子κB是如何被激活以响应TLR信号的方法 多种机制融合在一起来调节核因子κB。在开发了活细胞显微镜跟踪工作流程后，我们 发现与以前的概念相反，NFκB的动力学是高度振荡的。通过生成敲门 Rela-Venus小鼠，我们第一次能够测量原代细胞中的NFκB动态，揭示 作为健康巨噬细胞中核因子κB固有特征的振荡。 在初步研究的基础上，我们建议检验核因子κB振荡对健康至关重要的假设 巨噬细胞在维持其表观遗传的染色质状态时发挥作用。非振荡的核因子κB更有可能 改变巨噬细胞特有的染色质状态并导致疾病相关基因的改变 表情。此外，虽然振荡是普遍存在的，但它们的持续时间受到不同刺激的调制，从而允许 用于差异、刺激特异性基因表达程序。 总之，拟议的研究将大大有助于我们理解NFκB如何动态控制 决定生理和病理基因表达程序。

ABSTRACT Inflammatory signaling by macrophages in response to pathogens or tissue injury is the key determinant of the pathology and pathogenesis of infectious and non-infectious disease. The transcription factor NFκB controls the inflammatory gene expression programs, but it remains unclear how its regulation determines healthy or disease-associated gene expression responses. During the previous funding period, we have used a combined experimental / computational modeling approach to gain a predictive understanding of how NFκB is activated in response to TLR signaling and that multiple mechanisms converge to regulate NFκB. After developing a live cell microscopy tracking workflow we discovered that contrary to previous notions NFκB dynamics are highly oscillatory. By generating a knockin RelA-Venus mouse, we are able – for the first time – measure NFκB dynamics in primary cells revealing oscillations as an intrinsic hallmark of NFκB in healthy macrophages. Based on preliminary studies, we propose to test the hypothesis that NFκB oscillations are critical for healthy macrophage functions as they preserve their epigenetic chromatin state. Non-oscillatory NFκB is more likely to alter the macrophage-characteristic chromatin state and lead to altered, disease-associated gene expression. Further, while oscillations are pervasive, their duration is modulated by different stimuli, allowing for differential, stimulus-specific gene expression programs. Together, the proposed studies will substantially contribute to our understanding of how NFκB dynamic control determines physiological and pathological gene expression programs.