Fig. 5. Inhibition of Let-7b and Let-7c by Lin28a promoted chondrocyte reprogramming.

(A) Let-7 miRNA expression was assessed by RT-qPCR in primary chondrocytes transduced with control empty vector [Ct(EV)] or Lin28a lentivirus [Lin28a(TG)] and cultured at 1% O₂. *P < 0.05 and ***P < 0.005 compared with empty vector control. (B) Heatmap representing the fold increase in the 50 most changed Let-7b and Let-7c targets in Lin28a-overexpressing chondrocytes compared to control chondrocytes in RNA-seq analysis. Red arrows indicate the genes with increase in expression ≥200%. (C) Let-7 target gene expression (CDC34, E2F5, HMGA2, IGFBP2, and ZBTB5) measured by RT-qPCR in primary chondrocytes transduced with [Lin28a(TG)]; *P < 0.05 compared with control empty vector [Ct(EV)]. Primary chondrocytes were treated with anti–Let-7b, anti–Let-7c, and anti–Let-7 antibody control siRNA. (D) Let-7 target gene expression (CDC34 and HMGA2) measured by RT-qPCR; *P < 0.05 compared with control. (E) Chondrocyte anabolic gene expression (Col2 and PRG4) measured by real-time qPCR; *P < 0.05 compared with controls. (F) Western blot analysis of MMP13 level in conditioned medium. Data are means ± SEM.