Smooth muscle cell fate and plasticity in atherosclerosis.
Allahverdian Sima,Chaabane Chiraz,Boukais Kamel,Francis Gordon A,Bochaton-Piallat Marie-Luce
Current knowledge suggests that intimal smooth muscle cells (SMCs) in native atherosclerotic plaque derive mainly from the medial arterial layer. During this process, SMCs undergo complex structural and functional changes giving rise to a broad spectrum of phenotypes. Classically, intimal SMCs are described as dedifferentiated/synthetic SMCs, a phenotype characterized by reduced expression of contractile proteins. Intimal SMCs are considered to have a beneficial role by contributing to the fibrous cap and thereby stabilizing atherosclerotic plaque. However, intimal SMCs can lose their properties to such an extent that they become hard to identify, contribute significantly to the foam cell population, and acquire inflammatory-like cell features. This review highlights mechanisms of SMC plasticity in different stages of native atherosclerotic plaque formation, their potential for monoclonal or oligoclonal expansion, as well as recent findings demonstrating the underestimated deleterious role of SMCs in this disease.
The NLRP3 inflammasome and the emerging role of colchicine to inhibit atherosclerosis-associated inflammation.
Martínez Gonzalo J,Celermajer David S,Patel Sanjay
Atherosclerosis is considered a chronic inflammatory disease of the arterial wall. Recently, compelling evidence has arisen for the role of monocytes and neutrophils and a particular protein complex that resides within these cells - the NLRP3 inflammasome - in atherosclerosis-associated inflammation. It is now also known that cholesterol crystals are present through all stages of atherosclerosis and can activate the NLRP3 inflammasome within these inflammatory cells to produce interleukin 1β and interleukin 18 - key mediators in the inflammatory cascade that drive plaque progression and instability. In this review, we describe the role of monocytes/macrophages and neutrophils in atherosclerosis, outline mechanisms of activation of the NLRP3 inflammasome in the setting of atherosclerosis-associated inflammation and discuss potential therapies that specifically target the NLRP3 inflammasome and/or its downstream mediators in atherosclerosis, with a particular focus on the emerging role of colchicine.