Stroke, Vol 17, 709-713, Copyright © 1986 by American Heart Association
FM Yatsu, R Alam and S Alam
Foam cells are lipid-laden macrophages derived primarily from circulating
mononuclear cells and are a characteristic feature of atheromatous lesions.
The exact role of these foam cells in the pathogenesis of atherosclerotic
lesions remains uncertain, but one potential function is to take-up and
process excess interstitial arterial lipoproteins, suggested by their
extraordinary ability to engulf enormous quantities of modified low density
lipoproteins by the so-called "scavenging pathway." To test this
possibility, monocytes from 15 atherothrombotic brain infarct patients and
age and sex matched controls were isolated and cultured for 7-8 days in 20%
normal serum. The monocyte-derived macrophages were investigated for their
ability to bind, internalize and degrade both native and modified
(acetylated) LDL labelled with 125Iodine. While native LDL was metabolized
similarly, stroke macrophages displayed significantly reduced ability to
scavenge modified LDL. These findings suggest that insufficient processing
of interstitial arterial cholesterol by monocyte-derived macrophages may
contribute to the aggravation of atheroma formation. This inadequacy is
likely further compromised by reduced levels of serum high density
lipoprotein since the absence of a cholesterol-acceptor will promote the
slow but continued accumulation of lipids and the formation of foam cells.
ARTICLES
Scavenger activity in monocyte-derived macrophages from atherothrombotic strokes