Figure 7.

Increased CD47 expression in aging and replicative senescence. (A) Quantification of relative CD47 mRNA levels by qPCR. Expression levels of senescent cells were normalized to the respective proliferating control (white bar). Data are representative of three independent experiments. All values are means ± SEM. **P < 0.005, ***P < 0.0005, ****P < 0.0001. Statistically significant differences were determined by unpaired Student’s t test. (B) Representative immunofluorescence images from indicated cell types stained for CD47 (green) and Hoechst (blue). Scale bar: 20 µm, except for 3T3 cells: 50 µm. (C) Whole-cell lysates from indicated cell types were isolated and analyzed by Western blotting for the indicated proteins. Senescence was induced by chemical treatment (palbociclib, except for A549: etopsoside). Shown are representative blots of three independent experiments. GAPDH images are derived from the same blot as Fig. S3 (for Panc1 cells the same GAPDH loading control is additionally used in Fig. 8 G). (D) Representative immunofluorescence images of proliferating or senescent small epithelial cells (SAEC) stained for CD47 (green) and Hoechst (blue). scale bars indicate 20 µm. n = 2–3. (E) Western blot analysis of CD47 expression in SAEC cells. Senescence was induced by chemical treatment (palbociclib). GAPDH was used as loading control. n = 2. GAPDH images are derived from the same blot as Fig. S3. (F) Representative immunofluorescence images of primary lung fibroblast (proliferative or replicative senescent by serially passaging; normal healthy [NHLF] or IPF-derived [IPF]) showing CD47 (green) and Hoechst (blue) staining. scale bars indicate 20 µm. n = 2. (G) Whole-cell lysates from primary NHLF or IPF lung fibroblasts were isolated and analyzed by Western blotting for the indicated proteins. Senescence was induced by replicative passing. Shown are representative blots of three to four independent experiments. Source data are available for this figure: SourceData F7.