IMPACT OF DIFFERENT TYPES PHOTON RADIATION ON DNA DOUBLE-STRAND BREAKS REPAIR PROCESS IN MICROGLIAL CELLS

Microglial cells are innate immune effector cells in the central nervous system that react to stressors, such as ionizing radiation (IR). Cell line SIM-A9 may serve as a model system for the investigation of microglial behaviour in vitro in response to IR. In brain tissue exposure to IR can lead to increase of double strand breaks (DSBs) in microglial cells, which is of vital importance for genomic integrity. The aim of this study is to analyze the ability of cells to process DSBs after exposure to two different types of photon radiation - gamma-rays and X-rays. The amount of persisting DSBs in cells 2 h after exposure to 1 or 2 Gy (Co-60 or X-ray linear accelerator) is determined by Neutral Comet Assay. We observe significant differences between two types of radiation quality with higher dose of 2 Gy. The levels of unrepaired damage remain elevated in cells, irradiated with Co-60, unlike cells, irradiated with X-ray linear accelerator.