Oxidation Prevents HMGB1 Inhibition on PDGF-Induced Differentiation of Multipotent Vascular Stem Cells to Smooth Muscle Cells: A Possible Mechanism Linking Oxidative Stress to Atherosclerosis

Figure 1

The assessment of MVSC proliferative capacity after HMGB1 and oxidized HMGB1 treatment. The cells at passage 2 were treated with HMGB1, LO-HMGB1, and HO-HMGB1 at the concentration of 10 ng/ml and 100 ng/ml for 24 h. The negative control was HMGB1-untreated cells (the groups at 0 ng/ml). In CCK8 assay, cell survival was represented by average absorbance at 450 nm that was calculated from five repeated experiments and normalized to that of untreated cells. (a) HMGB1 treatment inhibited cell survival in a dose-dependent manner, which was blocked by HMGB1 Ab. (b) HO-HMGB1 at both 10 ng/ml and 100 ng/ml had less effect than HMGB1 on cell growth inhibition. The difference in cell growth between LO-HMGB1 and HMGB1 treatment groups was significant only at 100 ng/ml. In flow cytometry, the average percentage of Ki67-positive cells was calculated from three repeated tests. (c) HMGB1 treatment decreased the percentage of Ki67-positive cells, and HMGB1 Ab blocked the effect. (d) The percentage of Ki67-positive cells was significantly increased by 10 ng/ml and 100 ng/ml HO-HMGB1 treatment as compared to HMGB1 treatment. The difference in percentage of Ki67-positive cells between LO-HMGB1 and HMGB1 treatment was significant only at 100 ng/ml. Similarly, the percentage of Ki67-positive cells between LO- and HO-HMGB1 treatment groups was not significantly different until at 100 ng/ml. Group comparisons were made using one-way ANOVA. .

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