Figure 13.

Oxidative stress and UV-C radiation induce senescence that is partially dependent on the failure to disassemble the primary cilium. A–C) WI-38 human diploid fibroblasts were transfected with either scrambled (Scr) or IFT88 siRNA. A) Cells were treated with sublethal doses (450 μM) of H₂O₂ for 2 h, washed, and recovered in complete medium for 10 d. B) WI-38 fibroblasts were treated with UV-C radiation (10 J/m²) and cultured in complete medium for 10 d. C) WI-38 cells were treated with bleomycin (10 μg/ml) for 24 h. Cells were washed and cultured in complete medium for 10 d. Cell lysates were then subjected to immunoblot analysis with antibody probes specific for AURKA and β-actin to show equal loading. D–F) WI-38 fibroblasts were transfected and treated as described in A–C. Cells were then subjected to immunofluorescence staining with anti-acetylated α-tubulin IgGs to detect primary cilia. Quantification of cells carrying a primary cilium is shown. G–I) WI-38 fibroblasts were transfected and treated as described in A–C. Cells were then subjected to SA-β-galactosidase activity staining. Values represent means ± sem. *P < 0.001, ^#P < 0.005, ^$P < 0.05 (Student’s t test).