Astragalus Polysaccharide Inhibits Ionizing Radiation-Induced Bystander Effects by Regulating MAPK/NF-kappa B Signaling Pathway in Bone Mesenchymal Stem Cells (BMSCs)

作者：Zhang, Liying; Luo, Yali; Lu, Zhiwei; He, Jinpeng; Wang, Lei; Zhang, Lixin; Zhang, Yiming; Liu, Yongqi^*

来源：MEDICAL SCIENCE MONITOR, 2018, 24: 4649-4658.

DOI：10.12659/MSM.909153

• Bystander Effect
• Mesenchymal Stromal Cells
• Polysaccharides

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/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-beta 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, NE-kappa B 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-kappa B signal pathways in BMSCs. APS may block RIBE through regulating the MAPK/NF-kappa B pathway.

• 出版日期2018-7-6
• 单位中国科学院近代物理研究所