High Glucose Impairs Early and Late Endothelial Progenitor Cells by Modifying Nitric Oxide–Related but Not Oxidative Stress–Mediated
Mechanisms
Yung-Hsiang Chen 1 2 3 ,
Shing-Jong Lin 1 2 4 ,
Feng-Yen Lin 1 4 ,
Tao-Cheng Wu 1 2 4 ,
Chen-Rong Tsao 1 5 ,
Po-Hsun Huang 1 2 4 ,
Po-Len Liu 6 ,
Yuh-Lien Chen 7 and
Jaw-Wen Chen 1 2 4
1 School of Medicine, National Yang-Ming University, Taipei City, Taiwan
2 Cardiovascular Research Center, National Yang-Ming University, Taipei City, Taiwan
3 Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan
4 Division of Cardiology, Department of Medicine, National Taipei Veterans General Hospital, Taipei City, Taiwan
5 Taichung Veterans General Hospital, Taichung, Taiwan
6 Faculty of Respiratory Care, Kaohsiung Medical University, Kaohsiung, Taiwan
7 Department of Anatomy and Cell Biology, National Taiwan University, Taipei, Taiwan
Address correspondence and reprint requests to Jaw-Wen Chen, MD, Division of Cardiology, Department of Medicine, Taipei Veterans
General Hospital, No. 201, Sec. 2, Shih-Pai Road, Taipei 112, Taiwan. E-mail: jwchen{at}vghtpe.gov.tw
Abstract
OBJECTIVE—Endothelial progenitor cells (EPCs) are impaired in diabetes. This study aimed to investigate the direct effects
of high glucose on EPCs.
RESEARCH DESIGN AND METHODS—Mononuclear cells isolated from healthy subjects were incubated with glucose/mannitol or drugs
for EPC study. After 4 days of culture, attached early EPCs appeared. The monolayer late EPCs with cobblestone shape appeared
at 2–4 weeks. Various immunofluroscence stainings were used to characterize the early and late EPCs. Senescence assay and
the activity of endothelial nitric oxide synthase (eNOS) were determined. Migration and tube formation assay were done to
evaluate the capacity for vasculogenesis in late EPCs.
RESULTS—Chronic incubation with high glucose but not mannitol (osmotic control) dose-dependently reduced the number and proliferation
of early and late EPCs, respectively. High glucose enhanced EPC senescence and impaired the migration and tube formation of
late EPCs. High glucose also decreased eNOS, FoxO1, and Akt phosphorylation and bioavailable nitric oxide (NO) in both EPCs.
The effects of high glucose could be ameliorated by coincubation with NO donor sodium nitroprusside or p38 mitogen–activated
protein kinase inhibitor and deteriorated by eNOS inhibitor or PI3K (phosphatidylinositol 3′-kinase) inhibitor. Antioxidants
including vitamin C, N -acetylcysteine–and polyethylene glycol (PEG)-conjugated superoxide dismutase, and PEG-catalase had no effects, whereas pyrrolidine
dithiocarbamate, diphenyleneiodonium, apocynin, and rotenone even deteriorated the downregulation of both EPCs.
CONCLUSIONS—High glucose impaired the proliferation and function of early and late EPCs. NO donor but not antioxidants reversed
the impairments, suggesting the role of NO-related rather than oxidative stress–mediated mechanisms in hyperglycemia-caused
EPC downregulation.
acLDL, acetylated LDL
DiI-acLDL, 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine–labeled acLDL
eNOS, endothelial nitric oxide synthase
EPC, endothelial progenitor cell
l-NAME, l-Ng-nitro-l-arginine methyl ester
MAPK, mitogen-activated protein kinase
MNC, mononuclear cell
PEG, polyethylene glycol
MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
ROS, reactive oxygen species
VEGF, vascular endothelial growth factor
UEA-1, ulex europaeus agglutinin
Footnotes
Published ahead of print at http://diabetes.diabetesjournals.org on 26 March 2007. DOI: 10.2337/db06-1103.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore
be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Accepted March 12, 2007.
Received August 8, 2006.
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High Glucose Impairs Early and Late Endothelial Progenitor Cells by Modifying Nitric Oxide–Related but Not Oxidative Stress–Mediated Mechanisms

10.2337/db06-1103