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 2

The effect of HMGB1 and oxidized HMGB1 treatment on PDGF-induced differentiation of MVSCs to SMCs. The MVSCs were treated with PDGF-BB for 7 days to induce SMC differentiation. SM-MHC was detected by immunofluorescent assay to identify differentiated cells. HMGB1 treatment reduced the population of SM-MHC-positive cells (A, B, and D), which was blocked by HMGB1 Ab (C, E). In contrast, HO- and LO-HMGB1 treatment had less effect on the capacity of cell differentiation to SMCs (F–I). The results were confirmed by flow cytometry for SM-MHC-positive cells (J, K). HMGB1 treatment reduced the percentage of SM-MHC-positive cells in total cell population, and HMGB1 Ab blocked the effect (J). The percentages of SM-MHC-positive cells were significantly higher in HO- and LO-HMGB1 treatment groups than HMGB1 treatment group (K). The percentage of SM-MHC-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. .