Intracellular cholesteryl ester hydroperoxides and hydroxides- their metabolism and their modulation of cell function

Funded Activity Summary

Atherosclerosis is the disease which causes narrowings in arteries underlying such serious medical conditions as heart attack and stroke. A key component in the formation of atherosclerotic narrowings is the accumulation of fat-filled cells called foam cell macrophages in artery walls. Our study investigates the nature of the fats that macrophages accumulate, and how mild modification of these fats changes the metabolism of the macrophage. Cholesterol circulates in the blood stream as specialised particles called lipoproteins. The lipoprotein containing most of the cholesterol is low density lipoprotein (LDL), so-called bad cholesterol. LDL is the main source of fat that accumulates in the artery wall in atherosclerosis. When in the artery wall, it is taken up by macrophages which develop a foamy appearance. The accumulation of LDL fats within macrophages is greatly enhanced by the prior modification of LDL. The most well known of these modifications is oxidation- a chemical process of fat spoilage as occurs with rancid butter. Mild oxidation of LDL is well known to occur in human atherosclerosis. However, the ability of macrophages to accumulate the products of mild oxidation has never been established. We have recently discovered that the lipid products of mild oxidation of LDL can build up in macrophages. We achieved this by developing a new system of feeding oxidised LDL to macrophages. Surprisingly, not only could these lipid oxidation products be internalised by the cells, but they progressively accumulated over time, and caused major disturbances in the ability of macrophages to clear ordinary fats inside the cell. This means that mild oxidation of LDL can cause secondary damage inside the macrophage, which is far greater than had previously been realised. This project investigates precisely how the oxidised LDL is metabolised by macrophages and how it disturbs other cell functions.

Funded Activity Details

Start Date: 01-01-2000

End Date: 01-01-2002

Funding Scheme: NHMRC Project Grants

Funding Amount: $182,029.00

Funder: National Health and Medical Research Council

Research Topics

ANZSRC Field of Research (FoR)

Nutrigenomics and personalised nutrition

ANZSRC Socio-Economic Objective (SEO)

There are no SEO codes available for this funding activity

Other Keywords

atherosclerosis | coronary heart disease | lipoprotein | lysosome | macrophages | oxidation | stroke

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