Fig. 5.

Quantitative protein expression and representative Western blots (immediately beneath each graph) of preconditioned mesenchymal stem cells (MSC) following exposure to hypoxia. Western blots were performed to determine protein expression of (A) phosphorylated Akt1 at position 473 serine, (B) phosphorylated Bcl-2 at position 70 serine, and (C) phosphorylated NF-κB at position 536 serine in MSCs that underwent preconditioning with hyperoxia, caspase inhibitor (CI), or the combination prior to hypoxia exposure. Protein expression was determined as the ratio of phosphorylated to total protein expression. Phosphorylated protein expression of MSCs exposed to hypoxia is represented on the graphs as a percent relative to MSCs exposed only to normoxia without treatment (control) set at 100%. Preconditioning with hyperoxia and/or CI resulted in an increase in phosphorylated Akt1, Bcl-2, and NF-κB protein expression compared to MSCs with no preconditioning that were exposed to hypoxia. GAPDH Western blot is also shown as the loading control for all experiments (quantification of protein expression confirmed by computer analysis). P-values above columns represent comparison to control MSCs; NS, non-significant.