Fig. 1

Betaine concentration screening and its effect on chondrogenic differentiation of SCAPs. (A) Cell viability on SCAPs after 24 h and 48 h cultured with different concentrations of betaine. (B) RT-qPCR results for COL2, COL5 and SOX9 of chondrogenic induction for 2 weeks treated with betaine (5 mM). (C) Alcian Blue staining results of chondrogenic induction for 3 weeks treated with betaine (5 mM) and corresponding quantification (D). (E-G) Immunofluorescence images of anti-COL2, anti-COL5 and anti-SOX9 in SCAPs of chondrogenic induction treated with betaine (5 mM) for 1 week. (H) Fluorescence intensity of COL2, COL5 and SOX9 expression. (I) Alcian Blue and Sirius Red staining results of chondrogenic induced pellet and corresponding quantification treated with betaine (5 mM) for 3 weeks (J and K). n = 3 in each group. *p < 0.05, **p < 0.01, ***p < 0.001. Error bars: mean ± SD