Figure 2.

Immunostaining confirmed that UCMSCs could promote cartilage anabolism and alleviate cartilage catabolism. (A) Col-2 is evenly distributed on the whole cartilage, whereas MIA greatly decreased the expression, which is rescued by UCMSCs (upper panel). Aggrecanase ADAMTS-5 and collagen degradation enzyme MMP-13 is upregulated by MIA treatment, and UCMSCs effectively reduced its activity and attenuated catabolism (middle and lower panels). (Scale bars, 50 ​μm.) (B)–(D) Quantification of Col-2⁺, ADAMTS-5 ​and MMP-13⁺ cells in a fixed region. ∗p ＜ 0.05 ​and ∗∗∗p ＜ 0.001. (E) Quantification of hypertrophic chondrocytes in a fixed cartilage. ∗p ＜ 0.05. Results are representative of at least three independent experiments and expressed as mean ​± ​standard deviation. MIA = monosodium iodoacetate; UCMSCs = umbilical cord–derived mesenchymal stem cells.