Fig. 6

Effect of BMP pathway inhibition and PTHrP pulse treatment on bone formation and haematopoiesis 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. (A) Paraffin sections of n = 7–8 explants from n = 4 MSC donors per group were stained with HE to observe bone formation and haematopoiesis. Exemplary sections are marked with b for bone, ht for haematopoiesis and ft for fibrous tissue. Scale bars represent 150 μm. (B) HE-stained sections were scored by 6 blinded scorers to define bone formation (score from 0–3) and haematopoiesis (score from 0–3). Mean scores for each treatment regimen were calculated for each scorer for statistical evaluation (n = 6). Box plots were generated as described in Fig. 3. * p ≤ 0.05 Mann-Whitney U test compared to respective controls