Fig. 2

Normal WJ-MSCs treated with high levels of cortisol presented a poor capacity for chondrogenic differentiation and subsequent increased susceptibility to an osteoarthritis-like phenotype induced by IL-1β. a Safranin-O and Alcian blue staining for glycosaminoglycan in WJ-MSCs after chondrogenic differentiation for 21 days and IL-1β treatment for 1 day in 300, 600, and 1200 nM cortisol groups. b, c Relative quantification of Safranin-O and Alcian blue staining, n = 5. d, e RT-qPCR analysis of COL2A1, ACAN, MMP3, MMP13, and ADAMTS5 expression after chondrogenic differentiation and IL-1β treatment in 300, 600, and 1200 nM cortisol groups, n = 5. WJ-MSCs, Wharton’s jelly-derived mesenchymal stem cells; RT-qPCR, real-time quantitative polymerase chain reaction; COL2A1, α1 chain of type II collagen; ACAN, aggrecan; MMP, matrix metalloproteinase; ADAMTS5, a disinterring and metalloproteinase with thrombospondin motifs-5. Data are the mean ± S.E.M. **P < 0.01 vs control