International Genome Center, Jiangsu University, Zhenjiang, Jiangsu, P.R. China.
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu, P.R. China.
Turk J Med Sci. 2023 Sep 21;53(6):1621-1634. doi: 10.55730/1300-0144.5731. eCollection 2023.
BACKGROUND/AIM: Heavy-ion irradiation seriously perturbs cellular homeostasis and thus damages cells. Vascular endothelial cells (ECs) play an important role in the pathological process of radiation damage. Protecting ECs from heavy-ion radiation is of great significance in the radioprotection of normal tissues. In this study, the radioprotective effect of β-D-glucan (BG) derived from on human umbilical vein endothelial cell (EA.hy926) cytotoxicity produced by carbon-ion irradiation was examined and the probable mechanism was established.
EA.hy926 cells were divided into seven groups: a control group; 1, 2, or 4 Gy radiation; and 10 μg/mL BG pretreatment for 24 h before 1, 2, or 4 Gy irradiation. Cell survival was assessed by colony formation assay. Cell cycles, apoptosis, DNA damage, and reactive oxygen species (ROS) levels were measured through flow cytometry. The level of malondialdehyde and antioxidant enzyme activities were analyzed using assay kits. The activation of NF-κB was analyzed using western blotting and a transcription factor assay kit. The expression of downstream target genes was detected by western blotting.
BG pretreatment significantly increased the survival of irradiated cells, improved cell cycle progression, and decreased DNA damage and apoptosis. The levels of ROS and malondialdehyde were also decreased by BG. Further study indicated that BG increased the antioxidant enzyme activities, activated Src, and promoted NF-κB activation, especially for the p65, p50, and RelB subunits. The activated NF-κB upregulated the expression of antioxidant protein MnSOD, DNA damage-response and repair-related proteins BRCA2 and Hsp90α, and antiapoptotic protein Bcl-2.
Our results demonstrated that BG protects EA.hy926 cells from high linear-energy-transfer carbon-ion irradiation damage through the upregulation of prosurvival signaling triggered by the interaction of BG with its receptor. This confirms that BG is a promising radioprotective agent for heavy-ion exposure.
背景/目的：重离子辐照严重扰乱细胞内稳态，从而导致细胞损伤。血管内皮细胞（ECs）在辐射损伤的病理过程中发挥重要作用。保护 ECs 免受重离子辐射对于正常组织的放射防护具有重要意义。在本研究中，研究了来源于 β-D-葡聚糖（BG）对碳离子照射诱导的人脐静脉内皮细胞（EA.hy926）细胞毒性的保护作用，并建立了可能的机制。
EA.hy926 细胞分为七组：对照组；1、2 或 4 Gy 照射；以及 10 μg/mL BG 预处理 24 h 后再进行 1、2 或 4 Gy 照射。通过集落形成实验评估细胞存活率。通过流式细胞术测量细胞周期、凋亡、DNA 损伤和活性氧（ROS）水平。使用试剂盒分析丙二醛水平和抗氧化酶活性。使用 Western blot 和转录因子测定试剂盒分析 NF-κB 的激活。通过 Western blot 检测下游靶基因的表达。
BG 预处理显著提高了照射细胞的存活率，改善了细胞周期进程，降低了 DNA 损伤和凋亡。BG 还降低了 ROS 和丙二醛的水平。进一步的研究表明，BG 增加了抗氧化酶的活性，激活了 Src，并促进了 NF-κB 的激活，尤其是 p65、p50 和 RelB 亚基。激活的 NF-κB 上调了抗氧化蛋白 MnSOD、DNA 损伤反应和修复相关蛋白 BRCA2 和 Hsp90α 以及抗凋亡蛋白 Bcl-2 的表达。
我们的结果表明，BG 通过 BG 与其受体相互作用触发的生存信号的上调，保护 EA.hy926 细胞免受高传能线密度碳离子照射损伤。这证实了 BG 是一种有前途的重离子暴露放射保护剂。
