Involvement of protein kinase Cδ in induction of apoptosis by cationic liposomes in macrophage-like RAW264.7 cells

We have recently demonstrated that reactive oxygen species (ROS) play an important role in RAW264.7 cell apoptosis induced by cationic liposomes composed of stearylamine (SA-liposomes). In this study, we investigated whether protein kinase C delta PKC delta) is involved in apoptosis induced by cationic liposomes. Tyrosine phosphorylation, nuclear localization, and cleavage of PKCd were observed following the treatment of cells with SA-liposomes, suggesting that SA-liposomes activate PKCd. Rottlerin, a specific inhibitor of PKCd, inhibited ROS generation and also suppressed apoptosis. Cell surface proteoglycans may contribute to PKCd activation by SA-liposomes. These findings suggest that PKCd is strongly associated with apoptosis induced by SA-liposomes. (C) 2010 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.