Nonsteroidal Anti-Inflammatory Drugs Induced Endothelial Apoptosis by Perturbing Peroxisome Proliferator-Activated Receptor-δ Transcriptional Pathway

Recent studies have shown that use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with an increased risk of myocardial infarction. To explore whether NSAIDs may induce endothelial apoptosis and thereby enhance atherothrombosis, we treated human umbilical vein endothelial cells (HUVECs) with sulindac sulfide (SUL), indomethacin (IND), aspirin (ASA), or sodium salicylate (NaS), and we analyzed apoptosis. SUL and/or IND significantly increased annexin V-positive cells, cleaved poly(ADP-ribose) polymerase ( PARP) and caspase-3. ASA and NaS at 1 mM did not induce PARP cleavage or caspase-3 and at 5 mM, ASA but not NaS increased apoptosis. Because peroxisome proliferator-activated receptor delta-mediated 14-3-3 epsilon up-regulation was reported to play a crucial role in protecting against apoptosis, we determined whether NSAIDs suppress this transcriptional pathway. SUL, IND, and ASA ( 5 mM) suppressed PPAR delta and 14-3-3 proteins in a manner parallel to PARP cleavage. Neither ASA nor NaS at 1 mM interfered with PPAR delta or 14-3-3 epsilon expression. SUL inhibited PPAR delta promoter activity, which correlated with 14-3-3 epsilon promoter suppression. Suppression of 14-3-3 epsilon was associated with increased Bad translocation to mitochondria. Neither carbaprostacylin nor 4-(3-(2-propyl-3-hydroxy-4-acetyl)phenoxy)propyloxyphenoxy acetic acid (L-165041) prevented HUVECs from SUL-induced apoptosis. Because of suppression of ectopic PPAR delta by sulindac, adenoviral PPAR delta transduction failed to restore 14-3-3 epsilon or prevent PPAR cleavage. Our findings suggest that NSAIDs, but not aspirin (< 1 mM) induce endothelial apoptosis via suppression of PPAR delta-mediated 14-3-3 epsilon expression.