Research Paper Volume 11, Issue 12 pp 4145—4158

Intestinal stem cells acquire premature senescence and senescence associated secretory phenotype concurrent with persistent DNA damage after heavy ion radiation in mice

Figure 2. Heavy ion iron radiation leads to increased ROS and oxidative DNA damage in ISCs two months after exposure. (A) Representative flow cytometry histograms showing increased CellROX fluorescence in the upper right quadrant indicating increased ROS after iron radiation. (B) Quantification of mean fluorescent intensity data from five mice are presented as percent change in mean fluorescence in irradiated samples relative to controls demonstrates increased ROS in ISCs of iron irradiated mice. (C) Cells were incubated with mitochondrial fluorescent probe MitoSOX Red to assess mitochondrial ROS and representative flow cytometry histograms are presented to show increased mitochondrial ROS after iron irradiation. (D) Mean fluorescent intensity data from five mice was are graphically presented as percent change in irradiated relative to control samples. Significantly higher levels of mitochondrial ROS were detected after iron irradiation relative to control. (E) Sorted, fixed, paraffin embedded, and sectioned ISCs were stained for 8-oxo-dG and representative immunohistochemistry images are presented showing increased 8-oxo-dG stained nuclei after iron irradiation. Scale bars, 5 μm. (F) Quantification of number of 8-oxo-dG positive cells in ISC sections from control and irradiated mice. Data are presented graphically showing significantly higher 8-oxo-dG staining in irradiated samples relative to controls. Error bars show SEM.