Peter Seizer1, Saskia N I V Ungern-Sternberg2, Tanja Schönberger2, Oliver Borst2, Patrick Münzer2, Eva-Maria Schmidt2, Andreas F Mack2, David Heinzmann2, Madhumita Chatterjee2, Harald Langer2, Miroslav Malešević2, Florian Lang2, Meinrad Gawaz2, Gunter Fischer2, Andreas E May2. 1. From the Medizinische Klinik III, Kardiologie und Kreislauferkrankungen (P.S., S.N.I.v.U.-S., T.S., O.B., D.H., M.C., H.L., M.G., A.E.M.), Institute of Physiology (P.M., E.-M.S., F.L.), and Institute of Anatomy (A.F.M.), Eberhard Karls-University Tübingen, Tübingen, Germany; Institute of Biochemistry, Abteilung Enzymology, Martin-Luther-University Halle-Wittenberg, Halle, Germany (M.M.); and Max-Planck-Institute für Biophysikalische Chemie Göttingen, BO Halle (Saale), Germany (G.F.). peter.seizer@med.uni-tuebingen.de. 2. From the Medizinische Klinik III, Kardiologie und Kreislauferkrankungen (P.S., S.N.I.v.U.-S., T.S., O.B., D.H., M.C., H.L., M.G., A.E.M.), Institute of Physiology (P.M., E.-M.S., F.L.), and Institute of Anatomy (A.F.M.), Eberhard Karls-University Tübingen, Tübingen, Germany; Institute of Biochemistry, Abteilung Enzymology, Martin-Luther-University Halle-Wittenberg, Halle, Germany (M.M.); and Max-Planck-Institute für Biophysikalische Chemie Göttingen, BO Halle (Saale), Germany (G.F.).
Abstract
OBJECTIVE: Cyclophilin A (CyPA) is secreted under inflammatory conditions by various cell types. Whereas the important role of intracellular CyPA for platelet function has been reported, the effect of extracellular CyPA on platelet function has not been investigated yet. APPROACH AND RESULTS: Inhibition of extracellular CyPA through a novel specific inhibitor MM284 reduced thrombus after ferric chloride-induced injury in vivo. In vitro extracellular CyPA enhanced thrombus formation even in CyPA(-/-) platelets. Treatment of isolated platelets with recombinant CyPA resulted in platelet degranulation in a time- and dose-dependent manner. Inhibition of the platelet surface receptor extracellular matrix metalloproteinase inducer (cluster of differentiation 147) by an anticluster of differentiation 147 monoclonal antibody significantly reduced CyPA-dependent platelet degranulation. Pretreatment of platelets with CyPA enhanced their recruitment to mouse carotid arteries after arterial injury, which could be inhibited by an anticluster of differentiation 147 monoclonal antibody (intravital microscopy). The role of extracellular CyPA in adhesion could be confirmed by infusing CyPA(-/-) platelets in CyPA(+/+) mice and by infusing CyPA(+/+) platelets in CyPA(-/-) mice. Stimulation of platelets with CyPA induced phosphorylation of Akt, which could in turn be inhibited in the presence of phosphoinositid-3-kinase inhibitors. Akt-1(-/-) platelets revealed a markedly decreased degranulation on CyPA stimulation. Finally, ADP-induced platelet aggregation was attenuated by MM284, as well as by inhibiting paracrine-secreted CyPA without directly affecting Ca(2+)-signaling. CONCLUSIONS: Extracellular CyPA activates platelets via cluster of differentiation 147-mediated phosphoinositid-3-kinase/Akt-signaling, leading to enhanced adhesion and thrombus formation independently of intracellular CyPA. Targeting extracellular CyPA via a specific inhibitor may be a promising strategy for platelet inhibition without affecting critical functions of intracellular CyPA.
OBJECTIVE:Cyclophilin A (CyPA) is secreted under inflammatory conditions by various cell types. Whereas the important role of intracellular CyPA for platelet function has been reported, the effect of extracellular CyPA on platelet function has not been investigated yet. APPROACH AND RESULTS: Inhibition of extracellular CyPA through a novel specific inhibitor MM284 reduced thrombus after ferric chloride-induced injury in vivo. In vitro extracellular CyPA enhanced thrombus formation even in CyPA(-/-) platelets. Treatment of isolated platelets with recombinant CyPA resulted in platelet degranulation in a time- and dose-dependent manner. Inhibition of the platelet surface receptor extracellular matrix metalloproteinase inducer (cluster of differentiation 147) by an anticluster of differentiation 147 monoclonal antibody significantly reduced CyPA-dependent platelet degranulation. Pretreatment of platelets with CyPA enhanced their recruitment to mouse carotid arteries after arterial injury, which could be inhibited by an anticluster of differentiation 147 monoclonal antibody (intravital microscopy). The role of extracellular CyPA in adhesion could be confirmed by infusing CyPA(-/-) platelets in CyPA(+/+) mice and by infusing CyPA(+/+) platelets in CyPA(-/-) mice. Stimulation of platelets with CyPA induced phosphorylation of Akt, which could in turn be inhibited in the presence of phosphoinositid-3-kinase inhibitors. Akt-1(-/-) platelets revealed a markedly decreased degranulation on CyPA stimulation. Finally, ADP-induced platelet aggregation was attenuated by MM284, as well as by inhibiting paracrine-secreted CyPA without directly affecting Ca(2+)-signaling. CONCLUSIONS: Extracellular CyPA activates platelets via cluster of differentiation 147-mediated phosphoinositid-3-kinase/Akt-signaling, leading to enhanced adhesion and thrombus formation independently of intracellular CyPA. Targeting extracellular CyPA via a specific inhibitor may be a promising strategy for platelet inhibition without affecting critical functions of intracellular CyPA.
Authors: Saskia N I von Ungern-Sternberg; Sebastian Vogel; Britta Walker-Allgaier; Sascha Geue; Andreas Maurer; Anna-Maria Wild; Patrick Münzer; Madhumita Chatterjee; David Heinzmann; Elisabeth Kremmer; Oliver Borst; Patricia Loughran; Alma Zernecke; Matthew D Neal; Timothy R Billiar; Meinrad Gawaz; Peter Seizer Journal: Thromb Haemost Date: 2017-11-30 Impact factor: 5.249
Authors: Sebastian Vogel; Rebecca Bodenstein; Qiwei Chen; Susanne Feil; Robert Feil; Johannes Rheinlaender; Tilman E Schäffer; Erwin Bohn; Julia-Stefanie Frick; Oliver Borst; Patrick Münzer; Britta Walker; Justin Markel; Gabor Csanyi; Patrick J Pagano; Patricia Loughran; Morgan E Jessup; Simon C Watkins; Grant C Bullock; Jason L Sperry; Brian S Zuckerbraun; Timothy R Billiar; Michael T Lotze; Meinrad Gawaz; Matthew D Neal Journal: J Clin Invest Date: 2015-11-09 Impact factor: 14.808
Authors: David Heinzmann; Anna Bangert; Anna-Maria Müller; Saskia N I von Ungern-Sternberg; Frederic Emschermann; Tanja Schönberger; Madhumita Chatterjee; Andreas F Mack; Karin Klingel; Reinhard Kandolf; Miroslav Malesevic; Oliver Borst; Meinrad Gawaz; Harald F Langer; Hugo Katus; Gunter Fischer; Andreas E May; Ziya Kaya; Peter Seizer Journal: PLoS One Date: 2015-04-20 Impact factor: 3.240