Fig. 6.

Histological analysis of the ectopic chondrogenesis. a The samples of ectopic masses were subjected to H&E staining and Alcian Blue staining to determine the formation of chondrocyte-like cells and hypertrophic chondrocyte-like cells (magnification × 400, scale bar =50 μm). Representative images are shown. b The immunohistochemical staining was utilized to confirm the influence of silencing of Smad7 in BMP2-induced chondrogenic differentiation in vivo. The expression of collagen type 1 (COL1) and Collagen type 2 (COL2) was detected (magnification of images × 400, scale bar = 50 μm) (c). Immunofluorescence staining was used to determine the effects of Smad7 on the expression of a hypertrophic marker, including COL10 (green) and MMP13 (green) and DAPI (blue) (magnification of up images = × 400, scale bar = 50 μm). d, e Quantitative analysis of positive immunohistochemical stained area. Integral optical density/area (IOD/Area) was calculated with ImageJ software. f, g Immunofluorescence staining quantified analysis were used optical density by ImageJ. *P < 0.05, **P < 0.01