Fig. 2.

Differential responses of LPDL (non-senescent) and HPDL (senescent) HDFs to H₂O₂ induced apoptosis.

A, H₂O₂ at 100 μM or 200 μM was used to induce apoptosis in LPDL or HPDL. LPDL and HPDL fibroblasts were subjected to Annexin-V FITC assay 24 h after 2 h treatment of H₂O₂. Percentage (mean±SD) of fibroblasts apoptosis are measured by flow cytometry, results are average of at least three independent experiments. B, Caspase-3 activity assay. LPDL and HPDL HDFs were subjected to caspsae-3 activity assay 24 h after induced apoptosis with or without H₂O₂ at 100 μM for 2 h. Results are average± SD of caspse-3 activity of at least three independent experiments. ^⁎p<0.05: 24 h after 2 h treatment of 100 μm or 200 μM H₂O₂vs. its own group untreated control.