Haase M G, Klawitter A, Geyer P, Alheit H, Baumann M, Kriegel T M, Kasper M, Baretton G B
Department of Pathology, Carl Gustav Caruis Medical Faculty, Dresden University of Technology, Germany.
Int J Radiat Biol. 2003 Nov;79(11):863-77. doi: 10.1080/09553000310001632903.
To characterize the cellular distribution and DNA binding activity of the nuclear factor kappaB (NF-KappaB) in a model of radiation-induced lung damage in the rat.
The right lung of Fischer rats was irradiated with a single dose of 20 Gy. The cellular distributions of NF-KappaB proteins and mRNA were detected with immunohistochemistry and in-situ hybridization respectively. The DNA binding activity of NF-KappaB, nuclear and cytoplasmic levels of NF-KappaB proteins, and kinase activity towards IkappaBalpha (IKappaBAlpha) were determined using electrophoretic mobility shift assays (EMSA), Western blots and kinase assays, respectively. The mRNA level of interleukin 6 (IL-6) was determined using quantitative room temperature polymerase chain reaction.
There was a continuous elevation of NF-KappaB DNA binding activity in the rat lung after ionizing irradiation over 6 months. The irradiated lung tissue exhibited an increased kinase activity towards IKappaBAlpha and a selective loss of nuclear IKappaBAlpha. The NF-KappaB-DNA binding complex switched from p50-p65 heterodimers in normal lung tissue to p50 homodimers in irradiated lung tissue. The increased level of IL-6 mRNA suggests transcriptional activation of NF-KappaB-dependent genes in the irradiated rat lung.
The DNA binding activity of NF-KappaB is continuously activated after irradiation of the rat lung by loss of nuclear IKappaBAlpha. This might play a role in sustaining chronic inflammation and hyperproliferation of mesenchymal cells after irradiation.
在大鼠辐射诱导的肺损伤模型中，对核因子κB（NF-κB）的细胞分布和DNA结合活性进行表征。
对Fischer大鼠的右肺进行单次20 Gy的照射。分别采用免疫组织化学和原位杂交检测NF-κB蛋白和mRNA的细胞分布。分别使用电泳迁移率变动分析（EMSA）、蛋白质免疫印迹法和激酶分析测定NF-κB的DNA结合活性、NF-κB蛋白的核水平和细胞质水平以及对IκBα（IKappaBAlpha）的激酶活性。使用定量室温聚合酶链反应测定白细胞介素6（IL-6）的mRNA水平。
电离辐射后6个月内，大鼠肺中NF-κB的DNA结合活性持续升高。受照射的肺组织对IKappaBAlpha的激酶活性增加，且核内IKappaBAlpha选择性缺失。NF-κB-DNA结合复合物从正常肺组织中的p50-p65异二聚体转变为受照射肺组织中的p50同二聚体。IL-6 mRNA水平升高表明受照射大鼠肺中NF-κB依赖性基因的转录激活。
大鼠肺照射后，核内IKappaBAlpha缺失导致NF-κB的DNA结合活性持续激活。这可能在照射后维持慢性炎症和间充质细胞的过度增殖中起作用。
