Abstract:
Objective A nucleosomal protein, HMGB1, can be secreted by activated immune cells or passively released by dying cells, thereby amplifying rigorous inflammatory responses. In this study we aimed to test the possibility that radiation similarly induces cytoplasmic HMGB1 translocation and release.
Methods Human skin fibroblast (GM0639) and bronchial epithelial (16HBE) cells and rats were exposed to X-ray radiation, and HMGB1 translocation and release were then assessed by immunocytochemistry and immunoassay, respectively.
Results At a wide dose range(4.0-12.0 Gy), X-ray radiation induced a dramatic cytoplasmic HMGB1 translocation, and triggered a time- and dose-dependent HMGB1 release both in vitro and in vivo. The radiation-mediated HMGB1 release was also associated with noticeable chromosomal DNA damage and loss of cell viability.
Conclusions Radiation induces HMGB1 cytoplasmic translocation and extracellular release through active secretion and passive leakage processes.