Role of Heme Oxygenase-1 in Low Dose Radioadaptive Response

In this study, we focused on the possible role of heme oxygenase 1 (HO-1) in RAR. Consistent with previous studies, priming dose of X-ray radiation (1-10cGy) induced significant RAR in normal human skin fibroblasts (AG 1522 cells). Transcription and translation of HO-1 was up-regulated more than two fold by a priming dose of radiation (5cGy). Zinc protoporphyrin Ⅸ, a specific competitive inhibitor of HO-1, efficiently inhibited RAR whereas hemin, an inducer of HO-1, could mimic priming dose of X-rays to induce RAR. Knocking down of HO-1 by transfection of HO-1 siRNA significantly attenuated RAR. Furthermore, the expression of HO-1 gene was modulated by the nuclear factor (erythroid-derived 2)-like 2 (Nrf2), which translocated from cytoplasm to nucleus after priming dose radiation and enhance the antioxidant level of cells. Graphical abstract
Source: Redox Biology - Category: Biology Source Type: research