RESEARCH ARTICLE Apolipoprotein CIII regulates lipoprotein-associated phospholipase

Apolipoprotein CIII (apo CIII), a small glycoprotein that binds to the surfaces of certain lipoproteins, is associated with inflammatory and atherogenic responses in vascular cells. Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been proposed as an inflammatory biomarker and potential therapeutic target for cardiovascular disease (CVD). Here, we report that apo CIII increases Lp-PLA2 mRNA and protein levels in dose- and time- dependent manner in human monocytic THP-1 cells, and the increase can be abolished by MAPK and NFkB pathway inhibitors. Lp-PLA2 inhibitor, 1-linoleoyl glycerol attenuates the inflammation inducedbyapoCIII. In turn, exogenous Lp-PLA2 expression upregulates apo CIII and the upregulation can be inhibited by 1-linoleoyl glycerol in HepG2 cells. Moreover, plasma Lp-PLA2 level is correlated with apoCIII expression in pig liver. In vivo, Lp-PLA2 expression in monocytes and its activity in serum were significantly increased in human apo CIII transgenic porcine models comparedwithwild-typepigs.Our resultssuggest thatLp-PLA2andapo CIII expression level is correlated with each other in vitro and in vivo