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An update on the pathogenesis of atherosclerosis (principles of prevention, intervention, retardation, and
R W Wissler1, D Vesselinovitch
1Department of Pathology, University of Chicago Medical Center, Illinois.
Insights
Atherosclerotic plaque rupture causes major ischemic events. Smooth muscle cell proliferation, influenced by cholesterol and lipoproteins, is a key factor in plaque development and instability.
Area of Science:
- Cardiovascular Biology
- Atherosclerosis Research
- Cellular Pathophysiology
Background:
- Atherosclerotic plaques in arteries are the primary cause of life-threatening ischemic events.
- Plaque rupture or ulceration, particularly of the fibrous cap, leads to thrombosis and arterial events.
- Smooth muscle cells (SMCs) play a critical role in atherosclerotic plaque development.
Purpose of the Study:
- To elucidate the role of smooth muscle cells in atherosclerotic plaque formation and progression.
- To investigate the influence of lipid metabolism and endothelial injury on SMC proliferation in atherosclerosis.
Main Methods:
- Analysis of smooth muscle cell involvement in lipid uptake and plaque component synthesis.
- Examination of factors stimulating SMC proliferation, including serum cholesterol and lipoproteins.
- Assessment of the impact of endothelial injury and growth factors on SMCs.
Main Results:
- High serum cholesterol and low-density lipoproteins (LDL, B-VLDL) promote arterial medial cell proliferation and cholesteryl ester accumulation.
- High-density lipoproteins (HDL) demonstrate an inhibitory effect on these lipid-driven proliferative processes.
- Endothelial injury can independently stimulate SMC proliferation via growth factors from monocytes, endothelial cells, and platelets.
Conclusions:
- Smooth muscle cell proliferation is a significant driver of atherosclerotic plaque progression.
- Lipid profiles, particularly LDL and HDL levels, critically modulate SMC activity in atherosclerosis.
- Endothelial damage represents a distinct pathway that promotes SMC proliferation, contributing to plaque pathogenesis.
Abstract:
The major life-threatening ischemic events in heart and brain are precipitated by the plaque. Thrombosis in the muscular arteries and rupture of the large elastic arteries usually follows fracture or ulceration of the plaque's fibrous cap. The smooth muscle cell (SMC) participates in many aspects of the atherosclerotic process: lipid uptake, synthesis of plaque components, and cell proliferation. The latter is a particularly significant aspect of the disease. High serum cholesterol levels stimulate proliferation of arterial medical cells; lower-density lipoproteins (LDL and B-VLDL) induce ingress and storage of cholesteryl ester in the arterial intima. These effects are inhibited by high-density lipoproteins (HDL). Endothelial injury may be an important part of the pathogenesis of some atherosclerotic plaques because powerful growth factors liberated from circulating monocytes, injured endothelial cells, and platelets, actively stimulate SMC proliferation, even when other risk factors are absent.