Figure 4
DNA damage in HUVEC-STs triggered by NPs is the result of apoptosis. (A) Induction of apoptosis-dependent DNA fragmentation in HUVEC-STs after treatment with NPs [PLA/MMT/TRA, PLA/EDTMP, PLGA/MDP (100 μg/mL), or Pluronic F127 Ms (0.25 μg/mL)] at 24, 48, and 72 h estimated by the TUNEL assay. Results represent the mean ± SD of three independent experiments. *p < 0.05 for significant differences between NP-treated and control cells. (B) DNA fragmentation induced by NPs detected by agarose gel electrophoresis of DNA isolated from human endothelial cells. HUVEC-STs were treated for up to 72 h with 100 μg/mL of PLA/EDTMP, PLGA/MDP, and PLA/MMT/TRA or 0.025 μg/mL of Pluronic F127 Ms; 1—PLA/MMT/TRA, 2—PLA/EDTMP, 3—PLGA/MDP, 4—Control, 5—Pluronic F127 Ms. (C) NP effect (100 μg/mL of PLA/EDTMP, PLGA/MDP, and PLA/MMT/TRA or 0.025 μg/mL of Pluronic F127 Ms) on histone H2AX phosphorylation in human endothelial cells. *p < 0.05, **p < 0.01 for significant differences between NP-treated and control cells. Data are the means ± SD of three independent experiments. (D) Level of mRNA transcripts for histone H2AX gene in HUVEC-STs exposed to NPs (100 μg/mL of PLA/EDTMP, PLGA/MDP, and PLA/MMT/TRA or 0.025 μg/mL of Pluronic F127 Ms) for 24 h. Data are expressed as the means ± SD, (n = 3). Asterisks refer to level of significant (*p < 0.05, ***p < 0.001) difference in mRNA level in NP-treated cells compared to untreated control cells.
