Fig. 6

Effect of TGF-β inhibition on bioactivity of soluble ECM. a Medium conditions for pellet cultures were further supplemented with 10 μM SB-431542. b Safranin O staining. Scale bar = 500 μm. c Normalized sGAG contents show blunted anabolic effects of medium supplements (p < 0.05, n = 9); dotted line indicates sGAG/dsDNA content of control medium (without SB-431542). d Gene expression analysis shows complete inhibition of exogenous TGF-β and blunted tissue-specific bioactivity of ECM supplements (p < 0.05, n = 9). In (c and d), statistically significant differences are indicated by overlying horizontal lines. cECM urea-extracted cartilage extracellular matrix, SB SB-431542, sGAG sulfated glycosaminoglycan, tECM urea-extracted tendon extracellular matrix, TGF transforming growth factor