title: Heparin Decreases in Tumor Necrosis Factor α (TNFα)-induced Endothelial Stress Responses Require Transmembrane Protein 184A and Induction of Dual Specificity Phosphatase 1.
abstract: Despite the large number of heparin and heparan sulfate binding proteins, the molecular mechanism(s) by which heparin alters vascular cell physiology is not well understood. Studies with vascular smooth muscle cells (VSMCs) indicate a role for induction of dual specificity phosphatase 1 (DUSP1) that decreases ERK activity and results in decreased cell proliferation, which depends on specific heparin binding. The hypothesis that unfractionated heparin functions to decrease inflammatory signal transduction in endothelial cells (ECs) through heparin-induced expression of DUSP1 was tested. In addition, the expectation that the heparin response includes a decrease in cytokine-induced cytoskeletal changes was examined. Heparin pretreatment of ECs resulted in decreased TNFα-induced JNK and p38 activity and downstream target phosphorylation, as identified through Western blotting and immunofluorescence microscopy. Through knockdown strategies, the importance of heparin-induced DUSP1 expression in these effects was confirmed. Quantitative fluorescence microscopy indicated that heparin treatment of ECs reduced TNFα-induced increases in stress fibers. Monoclonal antibodies that mimic heparin-induced changes in VSMCs were employed to support the hypothesis that heparin was functioning through interactions with a receptor. Knockdown of transmembrane protein 184A (TMEM184A) confirmed its involvement in heparin-induced signaling as seen in VSMCs. Therefore, TMEM184A functions as a heparin receptor and mediates anti-inflammatory responses of ECs involving decreased JNK and p38 activity.
authors.affiliation: From the Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015.
authors.forename: Sara Lynn N
authors.initials: SL
authors.lastname: Farwell
authors.affiliation: From the Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, the Department of Chemistry, Lehigh University, Allentown, Pennsylvania 18103.
authors.forename: Daniela
authors.initials: D
authors.lastname: Kanyi
authors.affiliation: From the Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015.
authors.forename: Marianne
authors.initials: M
authors.lastname: Hamel
authors.affiliation: From the Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, the Department of Natural Sciences, DeSales University, Center Valley, Pennsylvania 18034.
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Slee
authors.affiliation: From the Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Miller
authors.affiliation: the Department of Surgery, Lehigh Valley Hospital Center, Allentown, Pennsylvania 18103, and.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Cipolle
authors.affiliation: From the Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, LJL0@lehigh.edu.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Lowe-Krentz
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D054638:Dual Specificity Phosphatase 1 / Q000235:genetics / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008565:Membrane Proteins; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D022502:Stress Fibers / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D033921:Vesicular Transport Proteins; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D011956:Receptors, Cell Surface; C000609639:Tmem184a protein, human; D014409:Tumor Necrosis Factor-alpha; D033921:Vesicular Transport Proteins; D006493:Heparin; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1
keywords: JNK; actin; endothelial cell; heparin-binding protein; inflammation; p38 MAPK