Clopidogrel significantly lowers the development of atherosclerosis in ApoE-deficient mice in vivo

Abstract

The anti-platelet drug clopidogrel has been shown to modulate adhesion molecule and cytokine expression, both playing an important role in the pathogenesis of atherosclerosis. The aim of this study was to investigate the impact of clopidogrel on the development and progression of atherosclerosis. ApoE(-/-) mice fed an atherogenic diet (cholesterol: 1 %) for 6 months received a daily dose of clopidogrel (1 mg/kg) by i.p. injection. Anti-platelet treatment was started immediately in one experimental group, and in another group clopidogrel was started 2 month after beginning of the atherogenic diet. Blood was analysed at days 30, 60 and 120 to monitor the lipid profile. After 6 months the aortic arch and brachiocephalic artery were analysed by Sudan IV staining for plaque size and by morphometry for luminal occlusion. Serum levels of various adhesion molecules were investigated by ELISA and the cellular infiltrate was analysed by immunofluorescence. After daily treatment with 1 mg/kg clopidogrel mice showed a significant reduction of atherosclerotic lesions in the thoracic aorta and within cross sections of the aortic arch [plaque formation 55.2 % (clopidogrel/start) vs. 76.5 % (untreated control) n = 8, P < 0.05]. After treatment with clopidogrel P-/E-selectin levels and cytokine levels of MCP-1 and PDGFβ were significantly reduced as compared to controls. The cellular infiltrate showed significantly reduced macrophage and T-cell infiltration in clopidogrel-treated animals. These results show that clopidogrel can effectively delay the development and progression of 'de-novo' atherosclerosis. However, once atherosclerotic lesions were already present, anti-platelet treatment alone did not result in reverse remodelling of these lesions.

CalDAG-GEFI Deficiency Reduces Atherosclerotic Lesion Development in Mice

“…In contrast, treatment of apoE−/− mice with the P2Y12 inhibitor clopidogrel bisulfate was associated with inconsistent results. While two groups found significant protection from atherosclerosis in clopidogrel-treated mice 27,28 , other groups could not reproduce these findings 29, 30 . Pharmacological inhibition is more likely to give variable results than a genetic approach.…”

“…Furthermore, treatment of atherosclerotic patients with the P2Y12 inhibitor, clopidogrel, reduced the number of P-selectin-positive platelets and platelet-leukocyte aggregates in blood 25, 26 . In mice, an anti-atherogenic effect of clopidogrel was reported by some investigators 27, 28 , while others could not reproduce these results 29, 30 .…”

P2Y 12 Promotes Migration of Vascular Smooth Muscle Cells Through Cofilin Dephosphorylation During Atherogenesis

“…It has been reported that clopidogrel reduces CD4 + , CD8 + T cells, and macrophages infiltration in plaque, and the reason may be because of reduced adhesion molecules level such as intercellular adhesion molecule-1, E-selectin/P-selectin and cytokine level such as membrane cofactor protein-1 and platelet-derived growth factor. 26 In addition, cytokines such as platelet-derived growth factor and transforming growth factor-β released by activated platelet have been demonstrated to enhance VSMCs migration or proliferation in vitro. 27,28 Thus, platelet inhibition may indirectly inhibit VSMCs migration or proliferation during atherogenesis.…”

P2Y12 Inhibition beyond Thrombosis: Effects on Inflammation

“…In a mouse model of atherosclerosis by Apolipoprotein E (ApoE) gene knock-out, genetic P2Y 12 deletion was associated with reduced lesion area, increased fibrous content at the plaque site and decreased inflammatory cell infiltration [159]. Likewise, clopidogrel and ticagrelor limited the progression of late atherosclerotic lesion and promoted plaque stability in ApoE knockout mice [160][161][162][163]. Unfortunately, differential analysis of the role of platelet and non-platelet P2Y 12 receptors was not possible with these studies.…”