Research Article

Comparing the Gene Expression Profile of Stromal Cells from Human Cord Blood and Bone Marrow: Lack of the Typical “Bone” Signature in Cord Blood Cells

Figure 5

Lentiviral overexpression of BMP4 in two USSC and two CBSC cell lines. With regard to the staining, only one representative cell line per cell type is shown. (a) Quantitative RT-PCR analysis of gene expression (in undifferentiated cells) after overexpression in relation to the control cells (Mock). RPL13A was used as housekeeping gene. (b): Representative illustration of the Oil Red O staining after adipogenic differentiation (21 d) of BMP4-transfected and control-cells. +: induced cells; −: non-induced cells. Lipid vacuoles are stained red. Scale bar: 100 μm. (c) ImageJ-based quantification of Oil Red O staining. * to 0.05, significant (unpaired -test). (d) Osteogenic differentiation experiments in overexpressed and Mock cells. After 14 days of differentiation, Von Kossa and Alizarin Red S staining were performed in the induced (+) and non-induced (−) cells. Mineralized areas are stained in brown/black or red, respectively. Scale bar: 200 μm. (e) Subsequent quantification of the bound Alizarin Red S-dye. ** to 0.005, very significant; *** , extremely significant (unpaired -test). (f) Safranin O staining of transfected and control cells after chondrogenic differentiation in pellet culture for 21 days. Proteoglycans are stained purple/red. Scale bar: 200 μm. BMP4: bone morphogenetic protein 4, LRP5: low-density lipoprotein receptor-related protein 5, RUNX2: runt-related transcription factor 2, and RPL13A: ribosomal protein L13A.
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