Figure 4.

Disruption of WNT16 results in apoptosis of superficial cartilage cells and in the loss of superficial zone molecular markers. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining of representative sections from the medial compartment of the knee of wild-type (WT) and wnt16^−/− mice 2 days after destabilisation of the medial meniscus (DMM) (N=6) (A). The TUNEL staining (shown in red) was superimposed on the Nomarski image for anatomical orientation. Quantification of TUNEL-positive cells in the superficial and deep layers of the articular cartilage within the medial compartment (most affected in DMM) and lateral compartment (mildly or unaffected) (B). Gene expression analysis of superficial zone cells from wnt16^−/− mice with or without rescue with exogenous 200 ng/mL recombinant WNT16 (N=4) (C). KO, knockout. *p<0.05.