Protective Effect of CpG-Oligodeoxynucleotides Against Low- and High-LET Irradiation

• Main Authors: Chao Zhang, Min Zheng, Xiang-Hui Zhu, Sha Li, Jin Ni, Bai-Long Li, Hu Liu, Fu Gao, Jian-Ming Cai
• Format: Article
• Language: English
• Published: Cell Physiol Biochem Press GmbH & Co KG 2014-11-01
• Series: Cellular Physiology and Biochemistry
• Subjects: CpG-ODNs; Irradiation; Carbon beam; High-LET
• Online Access: http://www.karger.com/Article/FullText/366368
• ISSN: 1015-8987; 1421-9778

Background/Aims: CpG-oligodeoxynucleotides (ODNs) are synthetic DNA sequences containing unmethylated cytosine-guanine motifs with potent immunomodulatory effects. Previous reports showed a powerful protective effect of CpG-ODN against the damage induced by low-LET γ-rays. In this study, we explored whether CpG-ODN also protects against the damage induced by high-LET irradiation. Parallel experiments were performed with low-LET irradiation. Methods: RAW264.7 cells were incubated with 1 μM of CpG-ODN after γ-ray or carbon-beam irradiation. Cell death was then measured by PI/DAPI double staining, cell survival was assessed by colony-formation assays, DNA damage was evaluated by comet assays, cell cycle was monitored by flow cytometry, and the levels of apoptosis-related proteins were detected by western blots. Results: When irradiated cells were treated with the CpG-ODN, cell viability decreased, cell survival increased, DNA damage and G2/M-phase arrest were ameliorated, and apoptosis was inhibited. Conclusions: The CpG-ODN showed protective effects against low-LET γ-ray and high-LET carbon-beam irradiation. These effects might be associated with the repair of DNA damage and inhibition of apoptosis.