Coronary syndrome

Aims We analysed the possible protective role of human endothelial (EPCs) and smooth muscle (SPCs) progenitor cells on atherosclerosis development in apoE2/2RAG22/2 mice. We determined plasma levels of SPCs in coronary patients. Methods and results ApoE2/2RAG22/2 mice received four intravenous injections of saline, 5 105 SPCs, or 5 105 EPCs every other week, one (preventive approach) or 12(curative approach) weeks after starting a high fat diet. Derived-SPC levels were quantified from blood mononuclear cells of patients with stable angina (n 10) and acute coronary syndromes (ACS, n 9). SPCs reduced athero-sclerosis development by 42 % (P, 0.001), but had no effect on lesion progression. In the SPC group, collagen and smooth muscle cell content were increased (þ80%, P, 0.001, þ46%, P, 0.05, respect-ively), and macrophage content was decreased (241%, P, 0.05). In the curative approach, macro-phage content decreased by 40.5 % (P, 0.05) after SPC injection. EPC injection had no effect on atherosclerosis development or progression. Peripheral blood-derived SPC levels were reduced in patients with ACS compared with stable angina patients (P, 0.05). Conclusion We demonstrate that SPCs limit plaque development and promote changes in plaque com-position towards a stable phenotype in mice. Our finding in patients suggests that reduced peripheral blood-derived SPC levels might represent a mechanism contributing to plaque destabilization