Fig. 1
Oxidative stress induced OPG secretion from ACSs. (a) Amount of OPG secreted from ASCs exposed to H2O2 (100 μM) determined using an ELISA kit specific to human OPG. Conditioned media of ASCs exposed to H2O2 up to 48 hours were used for the analysis. TGF-β1 (5 ng/ml) was included as a soluble factor commonly present in damaged heart. Inset: viability of ASCs treated with H2O2 (100 μM) or TGF-β1 (5 ng/ml) for 48 hours. *p < 0.05 compared to untreated control. (b) Expression of OPG in ischemia–reperfusion (I/R)-injured rat heart examined by immunofluorescence staining. I/R-injured rat heart was collected 1, 3, and 7 days after the injury without ASC transplantation, and damaged heart was stained with antibodies specific to CD90 (red), a stem cell marker, and OPG (green). Nucleus was stained with DAPI (blue). (c) Expression of OPG in I/R-injured heart with ASC transplantation (1 × 106 cells/head). Two-dimensional immunofluorescence images were converted to 2.5D topological view images for clear presentation of staining intensity among groups. ASC adipose-derived stem cell, OPG osteoprotegerin, TGF-β1 transforming growth factor beta 1 (Color figure online)