cPLA2 activator peptide, PLAP, increases arachidonic acid release and apoptosis of vascular smooth muscle cells

Apoptosis of vascular smooth muscle cells (VSMCs) has recently drawn a lot of interest in various laboratories due to its importance in atherogenesis. We have shown previously that nitric‐oxide (NO) can induce apoptosis of VSMCs and that the NO‐induced apoptosis is accompanied by an increase in arachidonic acid release via cytoplasmic Ca2+‐dependent phospholipase A2 (cPLA2). We have demonstrated here that NO‐induced activation of cPLA2 leading to increased arachidonic acid release can be mimicked via direct activation of cPLA2 with a cPLA2 activator peptide, PLAP. The PLAP induced arachidonic acid release and apoptosis is inhibitable by a cPLA2‐specific inhibitor, AACOCF3, indicating the direct involvement of cPLA2. In this study, activation of cPLA2 appears to be preceded by activation and binding by PLAP indicating that the cPLA2 functions are mediated via PLAP. J. Cell. Physiol. 198: 48–52, 2004. © 2003 Wiley‐Liss, Inc.