Fig. 4

Senescence-related gene expression profiling of CBX4 wild-type and mutants in primary human OA chondrocytes. The heatmap depicts the relative gene expression by primary human OA chondrocytes transduced with CBX4 wild-type (WT) or four CBX4 mutants of a select group of genes quantified by qPCR array. Gene expression is shown as a log2 ratio of expression level by CBX4 mutant-transduced cells relative to the CBX4 WT-transduced condition. The genes in the heatmap are organized vertically based on their functional properties: green text labels (top y-axis) are genes associated with cell proliferation; black text labels (middle y-axis) are genes related to DNA damage repair and apoptosis; red text labels (bottom y-axis) are genes related to SASPs (senescence-associated secretory phenotypes) and cellular senescence. The most deleterious impact on CBX4 senomorphic capability was caused by the combination of CDM and SIM mutations (far right column). ^#P ≤ 0.1 *P ≤ 0.05, **P ≤ 0.01