title: Apelin-13 passes through the ADMA-damaged endothelial barrier and acts on vascular smooth muscle cells.
abstract: Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is associated with vascular dysfunction. The polypeptide apelin mediates two major actions on blood vessels. However, their combined effects on vascular function are not fully understood. The present study aimed to determine the effect of apelin-13 on myosin light chain (MLC) phosphorylation in vascular smooth muscle cells (VSMCs) under ADMA-induced endothelial leakage conditions. To assess the increased permeability induced by ADMA, human umbilical vein endothelium cells (HUVECs) were plated in transwell dishes. The FITC-dextran flux and FITC-apelin-13 flux through the endothelial monolayer were measured. To examine the effect of leakage of apelin-13 on MLC phosphorylation in HUVSMCs, transwell dishes were used to establish a coculture system with HUVECs in upper chambers and HUVSMCs in lower chambers. Western blot was performed to assess the phospho-MLC levels. ADMA increased endothelial permeability in a concentration- and time-dependent manner, accompanied by actin stress fiber assembly and intercellular gap formation. When HUVECs were treated with ADMA, the permeability to both macromolecular dextran and micromolecular apelin-13 increased significantly. Both p38 MAPK inhibitor and NADPH oxidase inhibitor could prevent HUVECs from the increased permeability, and the changes of cytoskeleton and intercellular junction, which were induced by ADMA. Apelin-13 passed through the ADMA-stimulated endothelial monolayer and increased the expression of phospho-MLC in VSMCs. These results suggest that ADMA increases endothelial permeability, which may involve the p38 MAPK and NADPH oxidase pathway. Apelin-13 can pass through the damaged endothelial barrier, and acts directly on VSMCs to increase MLC phosphorylation.
authors: Department of Nephrology, Affiliated Beijing Friendship Hospital, Faculty of Kidney Diseases, Capital Medical University, No. 95 Yong An Road, Xi Cheng District, Beijing 100050, China.
authors: Li-Yan
authors: LY
authors: Wang
authors: Dong-Liang
authors: DL
authors: Zhang
authors: Jun-Fang
authors: JF
authors: Zheng
authors: Yu
authors: Y
authors: Zhang
authors: Qi-Dong
authors: QD
authors: Zhang
authors: Wen-Hu
authors: WH
authors: Liu
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D001120:Arginine / Q000009:adverse effects / Q000031:analogs & derivatives*; D015153:Blotting, Western; D002199:Capillary Permeability; D002478:Cells, Cultured; D018920:Coculture Techniques / Q000379:methods; D003911:Dextrans / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007365:Intercellular Junctions / Q000187:drug effects / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects; D032389:Myocytes, Smooth Muscle / Q000187:drug effects*; D018994:Myosin Light Chains / Q000187:drug effects*; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D022502:Stress Fibers / Q000187:drug effects; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000098:Acetophenones; D003911:Dextrans; D007093:Imidazoles; D036341:Intercellular Signaling Peptides and Proteins; D018994:Myosin Light Chains; D011725:Pyridines; C495199:apelin-13 peptide; C015219:fluorescein isothiocyanate dextran; C018524:N,N-dimethylarginine; D001120:Arginine; C056165:acetovanillone; D019255:NADPH Oxidases; D048051:p38 Mitogen-Activated Protein Kinases; D016650:Fluorescein-5-isothiocyanate; C093642:SB 203580