Fig. 1
Effects of CBX4 on primary human chondrocytes. CBX4 was overexpressed in human OA chondrocytes using CBX4 WT lentiviral particles. A CBX4 gene expression (n = 6) and protein expression (representative Western blot) in the CBX4 WT and control lentiviral construct (Ctrl) transduced OA chondrocytes. Upon longer exposure of the Western blot, CBX4 protein expression in control transduced primary chondrocytes was comparable to levels of expression we observe in senescent WI-38 (passage 55) cells (data not shown). CBX4: 75 kDa, β-actin: 42 kDa. B SA-β-gal activity, protein expression of p16INK4A and DPP4, and EdU proliferation were detected using flow cytometry. C Senescence-associated secretory phenotype (SASP) secretion was measured in the culture supernatants of CBX4 WT and vector only control (Ctrl)-transduced OA chondrocytes. Ratio-paired t-tests were performed to compare control and CBX4 WT presented as a dot line graph; P values are listed in the figure