FIG. 4.

The effect of neutralizing antibodies against DKK1 and FRZB on 3D coculture pellets of hMSCs and hChs after 4 weeks of culture. Gene expression was determined by quantitative real-time polymerase chain reaction analysis (A, B). The expression of target gene was standardized to GAPDH expression. Bars show the mean ± SD of triplicate cultures. *P < 0.05; **P < 0.01; ***P < 0.005 versus control. (C) Paraffin sections of coculture pellets stained for glycosaminoglycan by Alcian blue and safranin O. (D) The expression of type II collagen was visualized by IHC and immunofluorescence (scale bar 50 μm). (E) Alizarin red for matrix mineralization (visible as dark red regions) and TUNEL assay for apoptosis (apoptotic nuclei were stained dark brown). (F) Collagen type X was measured by immunofluorescence. Data are based on eight samples. For each experiment, a representative section is shown. Color images available online at www.liebertpub.com/scd