Provincial-Level Key Laboratory for Molecular Medicine of Major Diseases and The Prevention and Treatment with Traditional Chinese Medicine Research in Gansu Colleges and Universities, Gansu University of Traditional Chinese Medicine, Lanzhou, Gansu, China (mainland).
Key Laboratory of Space Radiobiology of Gansu Province and Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu, China (mainland).
Med Sci Monit. 2018 Jul 6;24:4649-4658. doi: 10.12659/MSM.909153.
BACKGROUND This study investigated the effect of Astragalus polysaccharides (APS) on radiation-induced bystander effects (RIBE) in human bone mesenchymal stem cells (BMSCs) induced by irradiated A549 cells. MATERIAL AND METHODS A549 cells were irradiated with 2 Gy X-rays to obtain conditioned medium. BMSCs were incubated with the conditioned medium or APS. The levels of reactive oxygen species (ROS) and TGF-β were detected by ELISA. Cell survival, genomic instability, and DNA damages were detected by CCK-8 assay, colony formation assay, the micronucleus test and immunofluorescence assay, respectively. The protein and phosphorylation protein expression of p38, c-Jun N-terminal kinase (JNK), extracellular regulated protein kinase (ERK1/2), P65, and cyclooxygenase-2 (COX-2) in bystander effect cells were detected by Western blot. RESULTS The expression of COX-2 and ROS increased following stimulation with conditioned medium; this effect was inhibited by pre-exposing the cells to APS. BMSCs growth and colony formation rate decreased following stimulation with conditioned medium; this effect was suppressed by pre-exposing the cells to APS. In addition, the micronucleus rate and 53BP1 foci number increased after treatment with conditioned medium; this increase in BMSCs was inhibited by APS. The levels of phosphorylated p38, JNK, ERK1/2, NF-κB P65, and COX-2 proteins were increased by conditioned medium but were decreased by pre-treatment with APS. CONCLUSIONS RIBE in BMSCs induced by the irradiated A549 was mediated by the ROS in the conditioned medium and might be related to MAPK/NF-κB signal pathways in BMSCs. APS may block RIBE through regulating the MAPK/NF-κB pathway.
本研究探讨了黄芪多糖（APS）对受照射 A549 细胞诱导的人骨髓间充质干细胞（BMSCs）辐射诱导的旁观者效应（RIBE）的影响。
用 2 Gy X 射线照射 A549 细胞以获得条件培养基。将 BMSCs 与条件培养基或 APS 孵育。通过 ELISA 检测活性氧（ROS）和 TGF-β的水平。通过 CCK-8 测定法、集落形成测定法、微核试验和免疫荧光法分别检测细胞存活率、基因组不稳定性和 DNA 损伤。通过 Western blot 检测旁观者效应细胞中 p38、c-Jun N 端激酶（JNK）、细胞外调节蛋白激酶（ERK1/2）、P65 和环氧化酶-2（COX-2）的蛋白和磷酸化蛋白表达。
用条件培养基刺激后，COX-2 和 ROS 的表达增加；预先用 APS 处理细胞可抑制这种作用。用条件培养基刺激后，BMSCs 的生长和集落形成率降低；预先用 APS 处理细胞可抑制这种作用。此外，用条件培养基处理后，BMSCs 的微核率和 53BP1 焦点数增加；用 APS 预处理可抑制这种增加。经条件培养基处理后，磷酸化 p38、JNK、ERK1/2、NF-κB P65 和 COX-2 蛋白的水平升高，但经 APS 预处理后降低。
受照射 A549 诱导的 BMSCs 中的 RIBE 是由条件培养基中的 ROS 介导的，可能与 BMSCs 中的 MAPK/NF-κB 信号通路有关。APS 可能通过调节 MAPK/NF-κB 通路来阻断 RIBE。
