Format

Send to

Choose Destination
See comment in PubMed Commons below
Arterioscler Thromb Vasc Biol. 2012 Oct;32(10):2405-17. doi: 10.1161/ATVBAHA.112.248617. Epub 2012 Aug 16.

Moderate to high concentrations of high-density lipoprotein from healthy subjects paradoxically impair human endothelial progenitor cells and related angiogenesis by activating Rho-associated kinase pathways.

Author information

1
Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan.

Abstract

OBJECTIVE:

Recent clinical evidence has failed to demonstrate the benefits of elevation of serum high-density lipoprotein (HDL), suggesting potential loss of protective effects of HDL at high concentrations. This study aimed to investigate the concentration-related effects of HDL on in vitro and in vivo functions of human endothelial progenitor cells (EPCs) and related angiogenesis.

METHODS AND RESULTS:

Early and late outgrowth EPCs were generated from human circulating mononuclear cells. Oxidized low-density lipoprotein reduced viability of late outgrowth EPCs, which was reversed dose dependently by HDL. In the absence of oxidized low-density lipoprotein, HDL at low concentrations (5-50 μg/mL, equal to 0.5-5 mg/dL in human) enhanced EPC tube formation by activating phosphatidylinositol-3 kinase/Akt/endothelial NO synthase pathways. Moderate to high concentrations (400-800 μg/mL) of HDL paradoxically enhanced EPC senescence and impaired tube formation by activating Rho-associated kinase (ROCK) and inhibiting phosphatidylinositol-3 kinase/Akt and p38 mitogen-activated protein kinase pathways. Rho-associated kinase inhibitors, either Y27632 or statins, prevented high HDL-induced EPC senescence and improved in vitro tube formation, as well as in vivo capacity of angiogenesis of EPCs.

CONCLUSIONS:

While protecting EPCs from the injury of oxidized low-density lipoprotein, moderate to high concentrations of HDL paradoxically impaired EPCs and related angiogenesis in the absence of oxidized low-density lipoprotein by activating Rho-associated kinase pathways, providing mechanistic evidence of potential hazard effects of HDL.

PMID:
22904272
DOI:
10.1161/ATVBAHA.112.248617
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center