Fig. 4.

Hypertrophic chondrocytes disappear rapidly in DIO callus

(A) Representative images of Mmp13 IF staining (red) in callus tissues isolated from either lean or DIO mice at the indicated post-fracture time points. DAPI stains nuclei (blue). Scale bar = 100μm. (B) Quantitation of Mmp13-stained area in IF images. Mmp13-stained area was normalized to the soft-callus area and presented as area (%). (C) As in (A) except Col X is stained (green). (D) As in (B) except Col X-stained area is quantitated. All IF analyses were performed in 6 lean and 6 DIO callus tissues; 3 sections were analyzed in each. (E) RT-qPCR quantitation of Col10a1 mRNA (normalized to the level of β-actin mRNA). Quantitation was done on RNA purified from lean and DIO callus tissues at d14 post-fracture (n=3). Normalized level in lean callus is defined as 100.All bar graphs represent average ± SEM. (*) P < 0.05; (**) P < 0.01; (****) P < 0.0001 using student t-test and time-matched lean callus as a control.