Characterization of cardiosphere-derived cells.

CDCs were isolated from cardiac tissue explants of healthy pigs. The figure A shows explants in culture with some fibroblast-like cells migrating from them (A.I), cardiospheres with CDCs migrating from them (A.II) and CDCs in culture (A.III). Figure B shows the phenotypic analysis of CDCs by flow cytometry. Representative histograms together with the expression levels are shown. The expression level of cell surface markers is represented as Mean Relative Fluorescence Intensity (MRFI), which is calculated by dividing the Mean Fluorescent Intensity (MFI) (black lined histogram) by its negative control (grey lined histogram). Figure C corresponds to gene expression analysis by conventional RT-PCR. Mean ± SD of three different experiments are shown. Data are expressed as expression percentage referred to ACTB, used as control. The relative quantification was made by measuring the brightness intensity of each band with GeneSnap software. A representative image of one of the experiments is shown above. Figure D shows the differentiation potential of CDCs. Cells were maintained for 21 days with standard medium (control) (D.I) or with specific differentiation media for adipogenic, chondrogenic and osteogenic lineages. Differentiation was evidenced by specific stainings: Oil Red O for adipocytes (D.II), Alcian Blue for chondrocytes (D.III) and Alizarin Red S for osteocytes (D.IV).