Electronegative low-density lipoprotein.
OBJECTIVE
The occurrence in blood of an electronegatively charged LDL was described in 1988. During the 1990s reports studying electronegative LDL (LDL(-)) were scant and its atherogenic role controversial. Nevertheless, recent reports have provided new evidence on a putative atherogenic role of LDL(-). This review focuses on and discusses these new findings.


RESULTS
In recent years, LDL(-) has been found to be involved in several atherogenic features through its action on cultured endothelial cells. LDL(-) induces the production of chemokines, such as IL-8 and monocyte chemotactic protein 1, and increases tumor necrosis factor-alpha-induced production of vascular cell adhesion molecule 1, with these molecules being involved in early phases of leukocyte recruitment. LDL(-) from familial hypercholesterolemic patients also decreases DNA synthesis and intracellular fibroblast growth factor 2 production, which may contribute to impaired angiogenesis and increased apoptosis. In addition, the preferential association of platelet-activating factor acetylhydrolase with LDL(-) has been reported, suggesting a proinflammatory role of this enzyme in LDL(-).


CONCLUSIONS
Recent findings suggest that LDL(-) could contribute to atherogenesis via several mechanisms, including proinflammatory, proapoptotic and anti-angiogenesis properties. Further studies are required to define the role of LDL(-) in atherogenesis more precisely and to clarify mechanisms involved in endothelial cell activation.
Sánchez-Quesada
José Luis
JL
Biochemistry Department and Research Institute, Hospital de la Santa Creu i Sant Pau, C/Antoni Maria Claret 167, 08025 Barcelona, Spain.
Benítez
Sonia
S
Ordóñez-Llanos
Jordi
J
D000818:Animals; D001161:Arteriosclerosis / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000378:metabolism; D004560:Electricity; D004730:Endothelium, Vascular / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis; D008077:Lipoproteins, LDL / Q000378:metabolism / Q000502:physiology*; D012306:Risk; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis
D016209:Interleukin-8; D008077:Lipoproteins, LDL; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D016222:Fibroblast Growth Factor 2