Research Paper Volume 9, Issue 9 pp 1957—1970

The G-quadruplex DNA stabilizing drug pyridostatin promotes DNA damage and downregulates transcription of Brca1 in neurons

Figure 5. Ectopically expressed BRCA1 mitigates DNA damage associated with pyridostatin treatment. (А) Primary cortical neurons were transfected with GFP or with GFP-BRCA1 constructs, and then treated with a vehicle (control, GFP) or with 1 μM pyridostatin (GFP+PDS and GFP-BRCA1+PDS), overnight, fixed, and stained for a marker of DNA DSBs phosphorylated histone H2A variant X, γH2A.X (red). Scale bar is 10 μm. (B) The puncta index was estimated by measuring the standard deviation of the γH2A.X fluorescence intensity from (A). ***p<0.0001 (ANOVA). N.s., non-significant, p=0.243. A.u., arbitrary units. Two hundred neurons were analyzed from two independent experiments. (C) Primary cortical neurons were transfected with GFP or with GFP-BRCA1 constructs, and then treated with a vehicle (control, GFP) or with 1 μM pyridostatin (GFP+PDS, GFP-BRCA1+PDS), overnight, fixed, and stained for a marker of DNA DSBs 53BP1 (red). Scale bar is 10 μm. (D) The puncta index was estimated by measuring the standard deviation of the γH2A.X fluorescence intensity from (C). ***p<0.0001 (ANOVA). N.s., non-significant, p=0.441. A.u., arbitrary units. Two hundred neurons were analyzed from two independent experiments.