A-C, Cells were cultured in 10-cm culture dishes for 24 h. Cells were serum deprived for 3 h, followed by treatment with vehicle, hexadecenal (25 μM) or palmitic acid (25 μM) for 3 h. A, Apoptosis was determined by flow cytometry after Annexin V-FITC staining. B, Percentage of apoptotic cells (Annexin V positive) is shown in the histogram. Data are shown as mean ± SD. C, Cells were harvested and whole cell extracts were immunoblotted with PARP or actin antibodies. Immunoblots are representative of at least three independent experiments.