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Advanced glycation end product N ε ‐carboxymethyllysine induces endothelial cell injury: the involvement of SHP‐1‐regulated VEGFR‐2 dephosphorylation
Author(s) -
Liu Shing Hwa,
Sheu Wayne Huey Herng,
Lee Maw Rong,
Lee Wen Jane,
Yi Yu Chiao,
Yang Tzung Jie,
Jen Jen Fon,
Pan Hung Chuan,
Shen Chin Chang,
Chen Wen Bao,
Tien Hsing Ru,
Sheu Meei Ling
Publication year - 2013
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.4045
Subject(s) - protein tyrosine phosphatase , dephosphorylation , nadph oxidase , chemistry , cancer research , umbilical vein , reactive oxygen species , kinase insert domain receptor , vascular endothelial growth factor , tyrosine kinase , glycation , endothelial stem cell , microbiology and biotechnology , phosphatase , vascular endothelial growth factor a , phosphorylation , signal transduction , biochemistry , receptor , biology , in vitro , vegf receptors
N ε ‐carboxymethyllysine (CML), a major advanced glycation end product, plays a crucial role in diabetes‐induced vascular injury. The roles of protein tyrosine phosphatases and vascular endothelial growth factor (VEGF) receptors in CML‐related endothelial cell injury are still unclear. Human umbilical vein endothelial cells (HUVECs) are a commonly used human EC type. Here, we tested the hypothesis that NADPH oxidase/reactive oxygen species (ROS)‐mediated SH2 domain‐containing tyrosine phosphatase‐1 (SHP‐1) activation by CML inhibits the VEGF receptor‐2 (VEGFR‐2, KDR/Flk‐1) activation, resulting in HUVEC injury. CML significantly inhibited cell proliferation and induced apoptosis and reduced VEGFR‐2 activation in parallel with the increased SHP‐1 protein expression and activity in HUVECs. Adding recombinant VEGF increased forward biological effects, which were attenuated by CML. The effects of CML on HUVECs were abolished by SHP‐1 siRNA transfection. Exposure of HUVECs to CML also remarkably escalated the integration of SHP‐1 with VEGFR‐2. Consistently, SHP‐1 siRNA transfection and pharmacological inhibitors could block this interaction and elevating [ 3 H]thymidine incorporation. CML also markedly activated the NADPH oxidase and ROS production. The CML‐increased SHP‐1 activity in HUVECs was effectively attenuated by antioxidants. Moreover, the immunohistochemical staining of SHP‐1 and CML was increased, but phospho‐VEGFR‐2 staining was decreased in the aortic endothelium of streptozotocin‐induced and high‐fat diet‐induced diabetic mice. We conclude that a pathway of tyrosine phosphatase SHP‐1‐regulated VEGFR‐2 dephosphorylation through NADPH oxidase‐derived ROS is involved in the CML‐triggered endothelial cell dysfunction/injury. These findings suggest new insights into the development of therapeutic approaches to reduce diabetic vascular complications. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.