Fig. 4: Generating polarized growth plate-like structures by SOX9+ scl-progenitors-derived osteochondral fusions.
From: Recapitulation of endochondral ossification by hPSC-derived SOX9+ sclerotomal progenitors
A The experimental procedure to construct osteochondral fusion using SOX9+ scl-progenitor-derived osteo-spheroids (containing osteogenesis-committed early chondrocytes) and chondro-spheroids (containing day-14 chondroprogenitors. Scale bars: 500 μm. B The osteochondral fusions generated polarized growth plate-like tissues with unidirectional proliferating chondrocyte columns. Alizarin red: calcified region. Masson’s trichrome and Safranin O showed the overall morphology and the growth plate-like regions. The dotted line: proliferating zone. KU80 marked human cells. RZ, resting zone. PZ, proliferating zone. HZ, hypertrophic zone. Scale bars: 100μm. C Consistent formation of polarized growth plate-like tissues in the osteochondral fusion grafts. The width of the proliferating zones was measured and compared with transplants with chondro- and osteo-spheroids as controls. Error bars (mean ± sd) represented data from five independent transplants (two sections per transplant). Scale bars: 100 μm. Statistics: Student’s t-test (two-tailed), by SPSS v26.0. **p < 0.01 (p = 0.0011), ****p < 0.0001 (p = 0.00000025). D, E Similar expression of regional markers between the osteochondral fusion (E) with primary growth plate tissues from mouse femur at PN9 (D). COL II, pan-chondrocyte marker. IHH, prehypertrophic chondrocyte marker. COLX, hypertrophic chondrocyte marker. SP7, osteoblast, and bone progenitor marker. EMCN, endothelial marker. Scale bars: 100 μm. Source data are provided as a Source Data file.
