Mast cells, better known as allergy cells, are proinflammatory effector cells present in the human arterial intima and in evolving atherosclerotic lesions. Our understanding of the relationship between the proatherogenic activities of arterial mast cells (MCs) and the development of atherosclerotic lesions is advancing. Experiments in vitro, in vivo experiments in animals, and immunohistologic studies of human coronary samples have uncovered mechanisms by which activated mast cells could participate in the development of the lesions. When activated, mast cells acutely expel a fraction of their cytoplasmic granules, which are filled with a wide selection of heparin-bound preformed mediators. The microenvironmental targets of these effector molecules are various lipoprotein particles in the intimal fluid, components of the extracellular matrix, and intimal cells neighboring the activated mast cells. We propose that by promoting cholesterol accumulation and plaque vulnerability and by locally regulating hemostasis, MCs in atherosclerotic lesions have the potential to contribute to the clinical outcomes of atherosclerosis, such as myocardial infarction and stroke.

Selected publications

Lee-Rueckert M, Silvennoinen R, Rotllan N, Judström I, Blanco-Vaca F, Metso J, Jauhiainen M, Kovanen PT, Escola-Gil JC. Mast cell activation in vivo impairs the macrophage reverse cholesterol transport pathway in the mouse. Arterioscler Thromb Vasc Biol. 2011;31:520-7.

Swedenborg J, Mäyränpää MI, Kovanen PT. Mast cells: important players in the orchestrated pathogenesis of abdominal aortic aneurysms. Arterioscler Thromb Vasc Biol. 2011;31:734-40.

Lappalainen J, Lindstedt KA, Oksjoki R, Kovanen PT. OxLDL-IgG immune complexes induce expression and secretion of proatherogenic cytokines by cultured human mast cells. Atherosclerosis. 2011;214:357-63

Heikkilä HM, Trosien J, Metso J, Jauhiainen M, Pentikäinen MO, Kovanen PT, Lindstedt KA. Mast cells promote atherosclerosis by inducing both an atherogenic lipid profile and vascular inflammation. J Cell Biochem. 2010;109:615-23.

Strbian D, Kovanen PT, Karjalainen-Lindsberg ML, Tatlisumak T, Lindsberg PJ. An emerging role of mast cells in cerebral ischemia and hemorrhage. Ann Med. 2009;41:438-50.

Kovanen PT. Mast cells in atherogenesis: actions and reactions. Curr Atheroscler Rep. 2009;11:214-9.