plasma lipoprotein particle oxidation

Definition

Target type: biologicalprocess

The modification of a lipid or protein within a plasma lipoprotein particle by oxidation of the lipid or one or more amino acids. [GOC:BHF, GOC:mah]

Plasma lipoprotein particle oxidation is a complex process that plays a critical role in the development of atherosclerosis and cardiovascular disease. It involves the modification of lipoproteins, primarily low-density lipoproteins (LDLs), by reactive oxygen species (ROS). ROS, including free radicals like superoxide anions (O2-), hydroxyl radicals (OH-), and hydrogen peroxide (H2O2), can be generated from various sources, including inflammation, environmental pollutants, and metabolic processes.

When LDL particles encounter ROS, they undergo oxidation, leading to structural changes in their lipid and protein components. Oxidation of LDLs leads to the formation of oxidized LDL (oxLDL), which has several adverse effects:

1. Increased uptake by macrophages: oxLDL is readily taken up by macrophages in the arterial wall via scavenger receptors. This leads to the formation of foam cells, which are cholesterol-laden macrophages that contribute to plaque formation.

2. Inflammation: oxLDL activates inflammatory pathways, leading to the recruitment of inflammatory cells, such as monocytes and T cells, to the arterial wall. These cells further contribute to plaque development and instability.

3. Endothelial dysfunction: oxLDL can damage endothelial cells, the lining of blood vessels, leading to impaired vasodilation and increased permeability. This can facilitate the accumulation of inflammatory cells and lipids in the arterial wall.

4. Thrombosis: oxLDL can promote platelet aggregation and coagulation, increasing the risk of thrombus formation, which can lead to heart attack or stroke.

The oxidation process of LDL particles involves several steps:

1. Initiation: The process is initiated by the interaction of LDL with ROS, leading to the formation of lipid peroxyl radicals.

2. Propagation: Lipid peroxyl radicals react with other lipids in the LDL particle, leading to a chain reaction of oxidation.

3. Termination: The chain reaction is eventually terminated by the reaction of lipid peroxyl radicals with antioxidants or by the formation of stable oxidation products.

Factors that contribute to LDL oxidation include:

1. Increased ROS production: Conditions such as inflammation, smoking, diabetes, and hypertension can increase ROS production, leading to increased LDL oxidation.

2. Decreased antioxidant levels: Low levels of antioxidants, such as vitamin E, can increase susceptibility to LDL oxidation.

3. Genetic factors: Some individuals have genetic variations that make them more susceptible to LDL oxidation.

4. Lifestyle factors: A high-fat diet, lack of exercise, and stress can contribute to LDL oxidation.

In summary, plasma lipoprotein particle oxidation is a complex process that involves the modification of LDL particles by ROS. This process leads to the formation of oxLDL, which has several adverse effects on the cardiovascular system, ultimately contributing to the development of atherosclerosis and cardiovascular disease.'
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Proteins (1)

Compounds (18)