Figure 5.

Mice (n = 24) were sorted independent of mouse type (wild type vs. RAGE KO) and procedure (control vs. surgery) based on the severity of cartilage degradation as indicated by the modified Mankin score. The frequency of positive immunohistochemistry staining for HtrA-1 and TGF-β1 for early OA (Modified Mankin score of 1.5–3, n = 6) and late OA (Modified Mankin score >4, n = 5) samples are shown here. The trend in frequency of positive staining was compared using a Chi-Squared test. Positive TGF-β1 was observed at a high frequency in early OA samples, but at a significantly lower frequency in late OA samples (^**p < 0.01). Conversely, the frequency of HtrA-1 was significantly higher in late OA samples than in early OA samples (^*p < 0.05).