Carlsen Harald, Alexander George, Austenaa Liv M I, Ebihara Kanae, Blomhoff Rune
Department of Nutrition, Faculty of Medicine, University of Oslo, P.O. Box 1046 Blindern, N-0316 Oslo, Norway.
Mutat Res. 2004 Jul 13;551(1-2):199-211. doi: 10.1016/j.mrfmmm.2004.02.024.
A wide range of environmental stress and human disorders involves inappropriate regulation of NF-kappaB, including cancers and numerous inflammatory conditions. We have developed transgenic mice that express luciferase under the control of NF-kappaB, enabling real-time non-invasive imaging of NF-kappaB activity in intact animals. We show that, in the absence of stimulation, strong, intrinsic luminescence is evident in lymph nodes in the neck region, thymus, and Peyer's patches. Treating mice with stressors, such as TNF-alpha, IL-1alpha, or lipopolysaccharide (LPS) increases the luminescence in a tissue-specific manner, with the strongest activity observable in the skin, lungs, spleen, Peyer's patches, and the wall of the small intestine. Liver, kidney, heart, muscle, and adipose tissue exhibit less intense activities. Exposure of the skin to a low dose of UV-B radiation increases luminescence in the exposed areas. In ocular experiments, LPS- and TNF-alpha injected NF-kappaB-luciferase transgenic mice exhibit a 20-40-fold increase in lens NF-kappaB activity, similar to other LPS- and TNF-alpha-responsive organs. Peak NF-kappaB activity occurs 6h after injection of TNF-alpha and 12h after injection of LPS. Peak activities occur, respectively, 3 and 6h later than that in other tissues. Mice exposed to 360J/m(2) of UV-B exhibit a 16-fold increase in NF-kappaB activity 6h after exposure, characteristically similar to TNF-alpha-exposed mice. Thus, in NF-kappaB-luciferase transgenic mice, NF-kappaB activity also occurs in lens epithelial tissue and is activated when the intact mouse is exposed to classical stressors. Furthermore, as revealed by real-time non-invasive imaging, induction of chronic inflammation resembling rheumatoid arthritis produces strong NF-kappaB activity in the affected joints. Finally, we have used the model to demonstrate NF-kappaB regulation by manipulating the Vitamin A status in mice. NF-kappaB activity is elevated in mice fed a Vitamin A deficient (VAD) diet, and suppressed by surplus doses of retinoic acid (RA). We thus demonstrate the development and use of a versatile model for monitoring NF-kappaB activation both in tissue homogenates and in intact animals after the use of classical activators, during disease progression and after dietary intervention.
多种环境应激和人类疾病都涉及核因子κB（NF-κB）的调控异常，包括癌症和众多炎症性疾病。我们构建了在NF-κB控制下表达荧光素酶的转基因小鼠，能够对完整动物体内的NF-κB活性进行实时无创成像。我们发现，在无刺激情况下，颈部淋巴结、胸腺和派尔集合淋巴结中存在明显的强烈内在发光。用应激源如肿瘤坏死因子-α（TNF-α）、白细胞介素-1α（IL-1α）或脂多糖（LPS）处理小鼠，会以组织特异性方式增加发光，在皮肤、肺、脾、派尔集合淋巴结和小肠壁中可观察到最强的活性。肝脏、肾脏、心脏、肌肉和脂肪组织的活性较弱。皮肤暴露于低剂量紫外线B（UV-B）辐射会增加暴露区域的发光。在眼部实验中，注射LPS和TNF-α的NF-κB荧光素酶转基因小鼠晶状体中的NF-κB活性增加20至40倍，与其他对LPS和TNF-α有反应的器官相似。注射TNF-α后6小时和注射LPS后12小时出现NF-κB活性峰值。峰值活性分别比其他组织晚3小时和6小时出现。暴露于360J/m(2) UV-B的小鼠在暴露后6小时NF-κB活性增加16倍，其特征与暴露于TNF-α的小鼠相似。因此，在NF-κB荧光素酶转基因小鼠中，NF-κB活性也存在于晶状体上皮组织中，并且当完整小鼠暴露于经典应激源时会被激活。此外，通过实时无创成像显示，类似于类风湿性关节炎的慢性炎症诱导会在受影响的关节中产生强烈的NF-κB活性。最后，我们利用该模型通过操纵小鼠的维生素A状态来证明NF-κB的调控。喂食维生素A缺乏（VAD）饮食的小鼠NF-κB活性升高，而过量的视黄酸（RA）会抑制其活性。因此，我们展示了一种通用模型的开发和应用，该模型可用于监测在使用经典激活剂后、疾病进展过程中和饮食干预后，组织匀浆和完整动物体内的NF-κB激活情况。
