Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
Int J Mol Sci. 2018 Oct 16;19(10):3197. doi: 10.3390/ijms19103197.
Low-dose radiotherapy (LD-RT) for benign inflammatory and/or bone destructive diseases has been used long. Therefore, mechanistic investigations on cells being present in joints are mostly made in an inflammatory setting. This raises the question whether similar effects of LD-RT are also seen in healthy tissue and thus might cause possible harmful effects. We performed examinations on the functionality and phenotype of key cells within the joint, namely on fibroblast-like synoviocytes (FLS), osteoclasts and osteoblasts, as well as on immune cells. Low doses of ionizing radiation showed only a minor impact on cytokine release by healthy FLS as well as on molecules involved in cartilage and bone destruction and had no significant impact on cell death and migration properties. The bone resorbing abilities of healthy osteoclasts was slightly reduced following LD-RT and a positive impact on bone formation of healthy osteoblasts was observed after in particular exposure to 0.5 Gray (Gy). Cell death rates of bone-marrow cells were only marginally increased and immune cell composition of the bone marrow showed a slight shift from CD8⁺ to CD4⁺ T cell subsets. Taken together, our results indicate that LD-RT with particularly a single dose of 0.5 Gy has no harmful effects on cells of healthy joints.
低剂量放射治疗（LD-RT）用于良性炎症和/或骨破坏性疾病已有很长的历史。因此，对关节内存在的细胞的机制研究大多是在炎症环境下进行的。这就提出了一个问题，即 LD-RT 是否也会在健康组织中产生类似的效果，从而可能导致潜在的有害影响。我们对关节内的关键细胞的功能和表型进行了检查，即成纤维样滑膜细胞（FLS）、破骨细胞和成骨细胞以及免疫细胞。低剂量电离辐射对健康 FLS 的细胞因子释放以及参与软骨和骨破坏的分子仅有轻微影响，对细胞死亡和迁移特性没有显著影响。健康破骨细胞的骨吸收能力在 LD-RT 后略有降低，而在特定情况下（特别是接受 0.5 戈瑞（Gy）照射后），健康成骨细胞的骨形成能力受到积极影响。骨髓细胞的细胞死亡率仅略有增加，骨髓中免疫细胞的组成从 CD8+T 细胞亚群向 CD4+T 细胞亚群略有转移。总的来说，我们的结果表明，特别是单次剂量为 0.5 Gy 的 LD-RT 对健康关节细胞没有有害影响。
