Figure 5.

Adipogenic, chondrogenic, and osteogenic differentiation of chondroblasts from costal cartilage. (A): Chondroblasts migrating out of the costal cartilage explant at 4 days. (B): Chondroblasts migrating out of the explant at 10 days. (C): Reverse transcription-polymerase chain reaction showing upregulation of COLII, AG, and RUNX2 upon chondrogenic differentiation, upregulation of ALP and de novo expression of OX upon osteogenic differentiation, and de novo expression of LPL and PPARγ upon adipogenic differentiation. (D, E): Oil Red O staining of chondroblasts treated for 3 weeks with control medium (D) or adipogenic medium (E). (F, G): Uninduced cells stained with Alcian Blue (F) and alizarin red (G). (H, I): Tgfβ1-containing medium-treated cells stained with Alcian Blue (H) and alizarin red (I). (J, K): StemPro-C-treated cells stained with Alcian Blue (J) and alizarin red (K). (L, M): Osteogenic medium-treated cells stained with Alcian Blue (L) and alizarin red (M). (N): Quantification of chondrogenesis (Alcian Blue quantification). Data are expressed as fold differences, taking untreated controls as 1; ∗, p < .002. (O): Quantification of osteogenesis (alizarin red quantification). Data are expressed as fold differences, taking untreated controls as 1. Scale bars = 300 μm (A, B, L) ([F–M] are at the same magnification) and 50 μm (E) ([D, E] are at the same magnification). Abbreviations: AB, Alcian Blue; AG, aggrecan; AR, alizarin red; ALP, alkaline phosphatase; COLII, collagen II; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; LPL, lipoprotein lipase; osteog, osteogenic; OX, Osterix; PPARγ, peroxisome proliferator-activated receptor γ; Tgfβ1, transforming growth factor β1.