Ela Karshovska1, Zhen Zhao1, Xavier Blanchet1, Martin M N Schmitt1, Kiril Bidzhekov1, Oliver Soehnlein1, Philipp von Hundelshausen1, Nadine J Mattheij1, Judith M E M Cosemans1, Remco T A Megens1, Thomas A Koeppel1, Andreas Schober1, Tilman M Hackeng1, Christian Weber1, Rory R Koenen2. 1. From the Institute for Cardiovascular Prevention (IPEK) (E.K., Z.Z., X.B., M.M.N.S., K.B., O.S., P.v.H., R.T.A.M., A.S., C.W., R.R.K.) and Division of Vascular and Endovascular Surgery (Z.Z., T.A.K.), Ludwig-Maximilians-University Munich, Munich, Germany; Department of Pathology, Academic Medical Center (AMC), Amsterdam, The Netherlands (O.S.); German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany (O.S., P.v.H., A.S., C.W.); and Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (N.J.M., J.M.E.M.C., R.T.A.M., T.M.H., C.W., R.R.K.). 2. From the Institute for Cardiovascular Prevention (IPEK) (E.K., Z.Z., X.B., M.M.N.S., K.B., O.S., P.v.H., R.T.A.M., A.S., C.W., R.R.K.) and Division of Vascular and Endovascular Surgery (Z.Z., T.A.K.), Ludwig-Maximilians-University Munich, Munich, Germany; Department of Pathology, Academic Medical Center (AMC), Amsterdam, The Netherlands (O.S.); German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany (O.S., P.v.H., A.S., C.W.); and Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (N.J.M., J.M.E.M.C., R.T.A.M., T.M.H., C.W., R.R.K.). r.koenen@maastrichtuniversity.nl.
Abstract
RATIONALE: Besides their essential role in hemostasis, platelets also have functions in inflammation. In platelets, junctional adhesion molecule (JAM)-A was previously identified as an inhibitor of integrin αIIbβ3-mediated outside-in signaling and its genetic knockdown resulted in hyperreactivity. OBJECTIVE: This gain-of-function was specifically exploited to investigate the role of platelet hyperreactivity in plaque development. METHODS AND RESULTS: JAM-A-deficient platelets showed increased aggregation and cellular and sarcoma tyrosine-protein kinase activation. On αIIbβ3 ligation, JAM-A was shown to be dephosphorylated, which could be prevented by protein tyrosine phosphatase nonreceptor type 1 inhibition. Mice with or without platelet-specific (tr)JAM-A-deficiency in an apolipoprotein e (apoe(-/-)) background were fed a high-fat diet. After ≤12 weeks of diet, trJAM-A(-/-)apoe-/- mice showed increased aortic plaque formation when compared with trJAM-A(+/+) apoe(-/-) controls, and these differences were most evident at early time points. At 2 weeks, the plaques of the trJAM-A(-/-) apoe(-/-) animals revealed increased macrophage, T cell, and smooth muscle cell content. Interestingly, plasma levels of chemokines CC chemokine ligand 5 and CXC-chemokine ligand 4 were increased in the trJAM-A(-/-) apoe(-/-)mice, and JAM-A-deficient platelets showed increased binding to monocytes and neutrophils. Whole-blood perfusion experiments and intravital microscopy revealed increased recruitment of platelets and monocytes to the inflamed endothelium in blood of trJAM-A(-/-) apoe(-/-)mice. Notably, these proinflammatory effects of JAM-A-deficient platelets could be abolished by the inhibition of αIIbβ3 signaling in vitro. CONCLUSIONS: Deletion of JAM-A causes a gain-of-function in platelets, with lower activation thresholds and increased inflammatory activities. This leads to an increase of plaque formation, particularly in early stages of the disease.
RATIONALE: Besides their essential role in hemostasis, platelets also have functions in inflammation. In platelets, junctional adhesion molecule (JAM)-A was previously identified as an inhibitor of integrin αIIbβ3-mediated outside-in signaling and its genetic knockdown resulted in hyperreactivity. OBJECTIVE: This gain-of-function was specifically exploited to investigate the role of platelet hyperreactivity in plaque development. METHODS AND RESULTS:JAM-A-deficient platelets showed increased aggregation and cellular and sarcoma tyrosine-protein kinase activation. On αIIbβ3 ligation, JAM-A was shown to be dephosphorylated, which could be prevented by protein tyrosine phosphatase nonreceptor type 1 inhibition. Mice with or without platelet-specific (tr)JAM-A-deficiency in an apolipoprotein e (apoe(-/-)) background were fed a high-fat diet. After ≤12 weeks of diet, trJAM-A(-/-)apoe-/- mice showed increased aortic plaque formation when compared with trJAM-A(+/+) apoe(-/-) controls, and these differences were most evident at early time points. At 2 weeks, the plaques of the trJAM-A(-/-) apoe(-/-) animals revealed increased macrophage, T cell, and smooth muscle cell content. Interestingly, plasma levels of chemokines CC chemokine ligand 5 and CXC-chemokine ligand 4 were increased in the trJAM-A(-/-) apoe(-/-)mice, and JAM-A-deficient platelets showed increased binding to monocytes and neutrophils. Whole-blood perfusion experiments and intravital microscopy revealed increased recruitment of platelets and monocytes to the inflamed endothelium in blood of trJAM-A(-/-) apoe(-/-)mice. Notably, these proinflammatory effects of JAM-A-deficient platelets could be abolished by the inhibition of αIIbβ3 signaling in vitro. CONCLUSIONS: Deletion of JAM-A causes a gain-of-function in platelets, with lower activation thresholds and increased inflammatory activities. This leads to an increase of plaque formation, particularly in early stages of the disease.
Authors: Julia Barbara Kral; Waltraud Cornelia Schrottmaier; Manuel Salzmann; Alice Assinger Journal: Transfus Med Hemother Date: 2016-03-09 Impact factor: 3.747
Authors: Lea M Beaulieu; Lauren Clancy; Kahraman Tanriverdi; Emelia J Benjamin; Carolyn D Kramer; Ellen O Weinberg; Xianbao He; Samrawit Mekasha; Eric Mick; Robin R Ingalls; Caroline A Genco; Jane E Freedman Journal: PLoS One Date: 2015-07-06 Impact factor: 3.240
Authors: Emiel P C van der Vorst; Sanne L Maas; Almudena Ortega-Gomez; Jeroen M M Hameleers; Mariaelvy Bianchini; Yaw Asare; Oliver Soehnlein; Yvonne Döring; Christian Weber; Remco T A Megens Journal: Bio Protoc Date: 2017-06-20