Wang Jun, Oikawa Masakazu, Konishi Teruaki
The Center for Ion Beam Bioengineering and Green Agriculture, Hefei Institute of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
Single Cell Radiation Biology Team, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Chiba 263-8555, Japan.
Biology (Basel). 2023 Mar 9;12(3):419. doi: 10.3390/biology12030419.
Nuclear factor (erythroid-derived 2)-like 2 (NRF2), well-known as a master antioxidative response regulator in mammalian cells, is considered as a potential target for radiation protection and cancer therapy sensitization. We examined the response of NRF2 signaling in normal human lung fibroblast WI-38 cells to nucleus targeted irradiation by 3.4 MeV proton microbeam. Nucleus targeted irradiation stimulated the nucleus accumulation of NRF2 and the expression of its target gene, heme oxygenase 1 (HO-1). The nucleus accumulation of NRF2 increased from 3 h to 12 h post 500 proton irradiation. In the 500 protons range, higher number of protons resulted in increased NRF2 nucleus accumulation. Activating NRF2 with -butylhydroquinone reduced DNA double-strand break (DSB) formation in nucleus targeted irradiation by 15%. Moreover, ATM phosphorylation was found in nucleus targeted irradiation. Inhibiting ATM with ku55933 prevented NRF2 nucleus accumulation. Furthermore, nucleus targeted irradiation activated ERK 1/2, and ROS-ERK 1/2 signaling regulated NRF2 nucleus accumulation. Taken together, NRF2 signaling was activated by nucleus targeted irradiation and mitigated DNA DSB. The discovery of ATM and ERK 1/2 as upstream regulators of NRF2 signaling in nucleus targeted cells revealed new information regarding radiation protection.
核因子（红系衍生2）样2（NRF2）是哺乳动物细胞中著名的主要抗氧化反应调节因子，被认为是辐射防护和癌症治疗增敏的潜在靶点。我们研究了正常人类肺成纤维细胞WI-38中NRF2信号通路对3.4 MeV质子微束靶向细胞核照射的反应。靶向细胞核照射刺激了NRF2的细胞核积累及其靶基因血红素加氧酶1（HO-1）的表达。500次质子照射后，NRF2的细胞核积累从3小时增加到12小时。在500个质子范围内，质子数量越多，NRF2的细胞核积累增加。用叔丁基对苯二酚激活NRF2可使靶向细胞核照射中的DNA双链断裂（DSB）形成减少15%。此外，在靶向细胞核照射中发现了ATM磷酸化。用ku55933抑制ATM可阻止NRF2的细胞核积累。此外，靶向细胞核照射激活了ERK 1/2，并且ROS-ERK 1/2信号通路调节了NRF2的细胞核积累。综上所述，NRF2信号通路被靶向细胞核照射激活，并减轻了DNA DSB。ATM和ERK 1/2作为靶向细胞核细胞中NRF2信号通路的上游调节因子的发现揭示了有关辐射防护的新信息。
