Fig. 5
Effect of BMP pathway inhibition or PTHrP pulse treatment on mineralization of MSC-derived cartilage after 8 weeks in vivo
MSCs were subjected to chondrogenic induction in the presence of CompA, LDN21 or received PTHrP pulse treatment. After 28 days, samples were implanted in subcutaneous pouches on the back of SCID mice for 8 weeks. Paraffin sections of explants were stained with (A) toluidine blue, safranin O/fast green to visualize proteoglycan deposition or alizarin red to visualize mineralization. Shown is one representative experiment based on n = 7–8 implants from n = 4 MSC donors. (B) Mineralization analysis by micro-CT. Full 3D reconstructions (top row) and central sections (bottom row) with a colour-gradient (yellow-low to red-high) representing mineralization levels. Non-mineralized tissue was visualized in blue. All samples are shown in suppl. Fig. S4. Scale bars represent 500 μm. (C) Mineralized volume (MV) in mm3 referred to total volume (TV) in mm3 (n = 7–8 experiments from n = 4 MSC donors). Box plots were generated as described in Fig. 3. Mann-Whitney U test compared to respective controls