|Title:||Advanced glycation end product Nε-carboxymethyllysine induces endothelial cell injury: The involvement of SHP-1-regulated VEGFR-2 dephosphorylation||Authors:||SHING-HWA LIU||Keywords:||AGEs; CML; human endothelial cells; NADPH oxidase; ROS; SHP-1||Issue Date:||2013||Journal Volume:||230||Journal Issue:||2||Start page/Pages:||215-227||Source:||Journal of Pathology||Abstract:||
Nε-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 [3H]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.
|DOI:||10.1002/path.4045||SDG/Keyword:||6 n carboxymethyllysine; advanced glycation end product; protein tyrosine phosphatase SHP 1; reactive oxygen metabolite; reduced nicotinamide adenine dinucleotide phosphate oxidase; small interfering RNA; vasculotropin receptor 2; apoptosis; article; cell culture; cell proliferation; confocal laser microscopy; controlled study; endothelium cell; enzyme activity; enzyme analysis; flow cytometry; human; human cell; immunofluorescence; immunohistochemistry; immunoprecipitation; in vitro study; priority journal; protein dephosphorylation; protein expression; umbilical vein endothelial cell; Western blotting; Animals; Aorta; Diabetes Mellitus, Experimental; Endothelium, Vascular; Gene Silencing; Glycosylation End Products, Advanced; Human Umbilical Vein Endothelial Cells; Humans; Lysine; Male; Mice; Mice, Inbred C57BL; Phosphorylation; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Reactive Oxygen Species; RNA, Small Interfering; Transfection; Vascular Endothelial Growth Factor Receptor-2
|Appears in Collections:||毒理學研究所|
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