Elevated protein kinase C-? contributes to aneurysm pathogenesis through stimulation of apoptosis and inflammatory signaling.

ABSTRACT: Apoptosis of smooth muscle cells (SMCs) is a prominent pathological characteristic of abdominal aortic aneurysm (AAA). We have previously shown that SMC apoptosis stimulates proinflammatory signaling in a mouse model of AAA. Here, we test whether protein kinase C-? (PKC?), an apoptotic mediator, participates in the pathogenesis of AAA by regulating apoptosis and proinflammatory signals.Mouse experimental AAA is induced by perivascular administration of CaCl(2). Mice deficient in PKC? exhibit a profound reduction in aneurysmal expansion, SMC apoptosis, and transmural inflammation as compared with wild-type littermates. Delivery of PKC? to the aortic wall of PKC?(-/-) mice restores aneurysm, whereas overexpression of a dominant negative PKC? mutant in the aorta of wild-type mice attenuates aneurysm. In vitro, PKC?(-/-) aortic SMCs exhibit significantly impaired monocyte chemoattractant protein-1 production. Ectopic administration of recombinant monocyte chemoattractant protein-1 to the arterial wall of PKC?(-/-) mice restores inflammatory response and aneurysm development.PKC? is an important signaling mediator for SMC apoptosis and inflammation in a mouse model of AAA. By stimulating monocyte chemoattractant protein-1 expression in aortic SMCs, upregulated PKC? exacerbates the inflammatory process, in turn perpetuating elastin degradation and aneurysmal dilatation. Inhibition of PKC? may serve as a potential therapeutic strategy for AAA.

SUBMITTER: Morgan S 

PROVIDER: S-EPMC3442600 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature