Send to

Choose Destination
See comment in PubMed Commons below
Atherosclerosis. 2007 Oct;194(2):326-33. Epub 2006 Nov 28.

Aggregated low density lipoproteins decrease metalloproteinase-9 expression and activity in human coronary smooth muscle cells.

Author information

Cardiovascular Research Center, CSIC-ICCC-HSCSP, Barcelona, Spain.


Plaque stability largely depends on vascular smooth muscle cell (VSMC) function. VSMC secrete metalloproteinases (MMPs), matrix degrading endopeptidases, that regulate VSMC migration and function. Among them, gelatinase B or MMP-9 seems to have a protective effect by promoting a stable plaque phenotype. In macrophage foam cells oxidized LDL (oxLDL) uptake regulates MMP-9 expression. However, it is unknown whether VSMC-lipid loading by aggregated LDL (agLDL) internalization produces any effect on MMP-9 production by human resident vascular cells. In the present study, we analyzed the effect of lipid-internalization in MMP-9 and MMP-2 expression and activity and its consequences in VSMC migration. Our results show that agLDL-internalization down-regulates MMP-9 activity in a time-dependent manner up to 42% at 48h and in a dose-dependent manner up to 87% at 300 microg/mL. nLDL induced similar but not sustained decrease on MMP-9 activity. However, neither agLDL nor nLDL exerted any significant effect on MMP-2 and TIMP-1. VSMC regrowth after a scratch injury was significantly reduced by exposure to agLDL. We conclude that agLDL-lipid loading reduces MMP-9 activity and this effect is associated to inhibition of VSMC migration. Thus, agLDL internalization may have consequences on vascular remodeling after injury, and the stability of lipid-rich atherosclerotic plaques.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center