Fig. 4

Long-term RIPK1 knockdown led to apoptosis in primary chondrocyte cells. a Representative pictures of SA-β-gal staining at 15 days after shRIPK1 knockdown. b Statistical analysis of A and of SA-β-gal positive cells in IL-1β induced senescence with or without overexpression of RIPK1. c Representative flow cytometry plots for primary chondrocyte cells with RIPK1 knockdown for 15 days. Cells were stained with Annexin V-FITC/propidium iodide and analyzed for cell apoptosis distribution. d Statistical analysis of C for the presence of Annexin V (+)/PI (−) (early apoptosis) and Annexin V (+)/PI (+) (late apoptosis)