TY - JOUR
T1 - 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
AU - Huang, Chun-Yao
AU - Lin, Feng-Yen
AU - Shih, Chun-Ming
AU - Au, Heng-Kien
AU - Chang, Yu-Jia
AU - Nakagami, Hironori
AU - Morishita, Ryuichi
AU - Chang, Nen-Chung
AU - Shyu, Kou-Gi
AU - Chen, Jaw Wen
PY - 2012/11
Y1 - 2012/11
N2 - 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. CONCLUSION-: 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.
AB - 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. CONCLUSION-: 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.
KW - endothelial progenitor cells
KW - high-density lipoprotein
KW - Rho-associated protein kinase
KW - senescence
KW - statin
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U2 - 10.1161/ATVBAHA.112.248617
DO - 10.1161/ATVBAHA.112.248617
M3 - Article
C2 - 22904272
AN - SCOPUS:84866599179
SN - 1079-5642
VL - 32
SP - 2405
EP - 2417
JO - Arteriosclerosis, Thrombosis, and Vascular Biology
JF - Arteriosclerosis, Thrombosis, and Vascular Biology
IS - 10
ER -