Figure 1.

Runx1 is upregulated in Human Osteoarthritis. (A) X-ray from a patient with a varus malalignment of the right knee showing compression in the medial compartment (*) of the knee and a normal joint space in the lateral compartment (#) (Patient K1 in Table 1). Safranin O staining shows loss of extracellular matrix on the medial side of the joint versus normal extracellular matrix on the lateral side. White arrows indicate “OA clones”. (B) Graph shows mean +/− SEM quantification of immunoblots stained for Runx1 using 110 cartilage samples from both tibial and femur locations from n=5 patients (see Table 1 and Methods). Data from the medial and lateral compartments were compared using Tukey’s test, *=p<0.05. (C) A representative immunoblot from a human OA knee (Table 1, patient K2) using a Runx1-specific antibody shows overall increased Runx1 in n=4 medial cartilage samples compared to n=6 lateral cartilage samples. (D) Immunohistochemical staining of tissue samples from the same patient as shown in Figure 1C, using a Runx1 specific antibody on the lateral (spared) and medial (OA) compartments (20x).