Ionizing Radiation Induces HMGB1 Cytoplasmic Translocation and Extracellular Release.

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 ionizing radiation similarly induces cytoplasmic HMGB1 translocation and extracellular release. METHOD: Human skin fibroblast (GM0639) and bronchial epithelial (16HBE) cells and animals (rats) were exposed to X-ray radiation, and HMGB1 translocation and release were assessed by immunocytochemistry and immunoassay, respectively. RESULTS: . The radiation-mediated HMGB1 release was associated with noticeable chromosomal DNA damage and loss of cell viability. CONCLUSION: radiation induces HMGB1 cytoplasmic translocation and extracellular release through active secretion and passive leakage processes.