Biomedical Engineering Reference
In-Depth Information
Fig. 2
Role of oxidized LDL in the pathogenesis of atherosclerosis and cutaneous xanthomas.
Circulating LDL transverses the lesions of large arteries or skin, where the LDL is oxidized. h e
oxidized LDL induces adhesion molecule expression on endothelial cells. Circulating monocytes
adhere to the endothelial cells via the adhesion molecules and subsequently transmigrate into the
lesions, where the monocytes dif erentiate into macrophages. h e macrophages incorporate the
oxidized LDL and transform into foam cells. LDL, low-density lipoprotein; VCAM-1, vascular
cell adhesion molecule 1.
and 4-hydroxynonenal. h ese aldehydes then react with amino phospholipids
(such as phosphatidylethanolamine and phosphatidylserine) and the
N
ε
-amino
groups of apolipoprotein B-100 lysine residues. LDL isolated from atherosclerotic
plaques or xanthoma lesions possesses properties that resemble those of Ox-
LDL formed
in vitro
(Ylä-Herttuala
et al
. 1989, Ikeda
et al
. 2006). Much of our
knowledge on how LDL is converted to Ox-LDL originates from
in vitro
studies
exposing LDL to metal ions or to cells cultured in transition metal-containing
medium.
Oxidation by Chemicals
Copper ions are commonly used to oxidize LDL in prolonged periods of incubation.
h is method causes drastic alterations to the lipoprotein particle that, as a result,
gains alternative functions. For example, the resulting Ox-LDL (referred to as
highly oxidized Ox-LDL or Cu-LDL) is no longer able to ef ectively interact with
