Figure 2. Knockdown of receptor interacting serine/threonine kinase (RIPK) 1 attenuates cartilage degeneration in vivo. (A, B) Immunohistochemical staining of RIPK1 in mice transfected with Ad-NC and Ad-shRIPK1 (n = 10); scale bar = 200 μm. (C, D) Safranin O/Fast Green-stained articular cartilage; the degree of cartilage degeneration was evaluated by calculating the OARSI score (n = 10); scale bar = 200 μm. (E, F) Immunohistochemical staining of matrix metalloproteinases (MMPs; n = 10); scale bar = 200 μm. (G, H) Representative HE-stained images and synovial inflammation scores (n = 10); scale bar = 200 μm. Columns represent means ± SD. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.