Role of atheroma liposomes and malondialdehyde-modified low-density lipoproteins in complement activation.
We investigated the ability of atheroma-associated liposomes and malondialdehyde (MDA)-modified low-density lipoproteins (MDA-LDL) to activate complement. Complement activation markers C3a, Bb, C4d and SC5b-9 were measured in both normal and complement-deficient sera. We found that MDA-LDL was able to generate C3a and SC5b-9, predominantly by the alternative pathway. High-density lipoproteins modified with MDA were also capable of C3a generation although to a lesser degree. The presence of atheroma-associated liposomes did not result in detectable levels of complement activation markers. We conclude that MDA-modified lipoproteins may represent a possible source for complement activation within atherosclerotic lesions.
Department of Pathology (113), Baltimore VAMC, MD 21201, USA.
J M
JM
Sorace
S
S
Rollins
J U
JU
Aniagolu
W J
WJ
Mergner
K
K
Cole
G M
GM
Swartz
S J
SJ
Green
D001018:Aortic Diseases / Q000378:metabolism / Q000503:physiopathology; D001161:Arteriosclerosis / Q000378:metabolism / Q000503:physiopathology*; D002784:Cholesterol / Q000302:isolation & purification / Q000494:pharmacology*; D002788:Cholesterol Esters / Q000302:isolation & purification / Q000494:pharmacology*; D003167:Complement Activation / Q000187:drug effects*; D015926:Complement C3a / Q000032:analysis; D003179:Complement C3b / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D015935:Complement C4b; D015938:Complement Membrane Attack Complex / Q000032:analysis; D003170:Complement Pathway, Alternative / Q000187:drug effects; D006801:Humans; D015227:Lipid Peroxidation; D008075:Lipoproteins, HDL / Q000494:pharmacology; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008081:Liposomes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008315:Malondialdehyde / Q000494:pharmacology*; D010446:Peptide Fragments / Q000032:analysis
D002788:Cholesterol Esters; D003181:Complement C4; D015938:Complement Membrane Attack Complex; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008081:Liposomes; D010446:Peptide Fragments; C099252:oxidized low density lipoprotein; D008315:Malondialdehyde; D015926:Complement C3a; D003179:Complement C3b; D015935:Complement C4b; C032261:complement C4d; D002784:Cholesterol