GC-Rich Extracellular DNA Induces Oxidative Stress, Double-Strand DNA Breaks, and DNA Damage Response in Human Adipose-Derived Mesenchymal Stem Cells

Figure 5

Exposure to either gDNA or GC-DNA supports cell survival. (a) Detection of haMSCs with sings of early apoptosis (FACS). HaMSCs were exposed to DNA samples (50 ng/mL, 3 h). (A) The distribution of fluorescence intensities of the cells stained with Annexin V-FITC; (B) the proportion of Annexin V-positive cells in total cell population. (b) The ratio of the levels of mRNA BCL2, BCL2A1 (Bfl-1/A1), BCL2L1 (BCL-X), BIRC3 (c-IAP1), and BIRC2 in cells exposed to 50 ng/mL gDNA, pBR322, or GC-DNA. The incubation time is indicated on the histogram. (c) Detection of BCL2 protein level in haMSCs exposed to DNA samples (50 ng/mL, 14 days). Cells were fixed with 3% PFA, treated with 0.1% Triton X-100 and stained with anti-BCL2 (FITC) antibodies. (A) FACS analysis showing the stained cellular fractions (SSC-FL1 (BCL2) diagram). Gate R encircles the fraction of haMSCs that express large amounts of protein BCL2; (B) the proportion of cells with large amounts of protein BCL2 (gate R); (C) the average of the median signal intensity of FL1 (BCL2) in haMSCs. Horizontal bars reflect relative expression levels in the control cells. Data points were averaged and represented as mean ± SD for three biological replicates. Asterisk   depicts the differences between exposed cells and control cells that were statistically significant by the Mann-Whitney U test ().

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