Adenovirus-mediated gene transfer of a secreted form of human macrophage scavenger receptor inhibits modified low-density lipoprotein degradation andfoam-cell formation in macrophages
J. Laukkanen et al., Adenovirus-mediated gene transfer of a secreted form of human macrophage scavenger receptor inhibits modified low-density lipoprotein degradation andfoam-cell formation in macrophages, CIRCULATION, 101(10), 2000, pp. 1091-1096
Citations number
27
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Background-Macrophage scavenger receptors (MSRs) play an;important role in
the pathogenesis of atherosclerosis. Therefore, local modulation of MSR act
ivity could have a beneficial effect on atherogenesis.
Methods and Results-We cloned a secreted "decoy" MSR (sMSR) that contains a
n extracellular portion of the human MSR type AI and constructed an adenovi
ral vector that directs high-level expression of sMSR in macrophages under
the control of the human CD68 promoter. Expression of the sMSR protein inhi
bited the degradation of I-125-labeled acetylated LDL and oxidized LDL by m
urine macrophages up to 90%. sMSRs also reduced acetylated LDL degradation
in MSR knockout mouse peritoneal macrophages by 60% to 80%, Which suggests
that the decoy construct can compete for the uptake mediated via other rela
ted scavenger receptors. In addition, sMSRs inhibited foam-cell formation i
n murine macrophages in the presence of cytochalasin D. The mechanism of in
hibition is through ligand binding to the sMSRs, which prevents the ligand
binding to MSRs on cell membranes.
Conclusions-The demonstration that recombinant adenovirus-mediated gene tra
nsfer of decoy sMSRs can block foam-cell formation suggests a possible new
strategy for gene therapy of atherosclerosis and for the treatment of lipid
accumulation after arterial manipulations.