Effect of hGSE mRNA on DDR after GE with AAV. (A) Representative flow cytometric dot plots showing γH2AX expression in CD34⁺ cells (naive, AAV alone without Cas9/sgRNA-induced DSB, Cas9/sgRNA-induced DSB + AAV) 2 hours after treatment. (B) Histogram summarizing the percentages of γH2AX⁺ marker in the conditions indicated at 24 hours (h) after DSB induced by Cas9/sgRNA (data represent 2-7 independent experiments). (C) Evolution of percentages of γH2AX⁺ cells after 48 to 96 hours after treatment (data represent 2-7 independent experiments). Paired sample Student t test was used to compare the proportion of positive cells at 24 and 48 hours. (D) Percentage of CD34⁺ cells in G₁, S, or G₂/M cell cycle phases at 24 and 48 hours after treatment. Significance compared with naive condition is indicated. (E) Histograms summarizing the percentages of cleaved poly(ADP-ribose) polymerase (c-PARP)⁺ cells, a marker of apoptosis, at 24 hours in the conditions indicated (data are representative of 3 independent experiments). (F) Proliferation index (FlowJo software) comparing carboxyfluorescein succinimidyl ester (CFSE)–stained HSPCs at day 1 and day 6 post-EP (data are representative of 3 independent experiments). Data are shown as mean ± SD. ANOVA 1-way test and Tukey’s post hoc multiple comparisons test were used. *P < .05; **P < .01; ***P < .001; ****P < .0001. SSC, side scatter.