title: Binding of thrombin-activated platelets to a fibrin scaffold through α(IIb)β₃ evokes phosphatidylserine exposure on their cell surface.
abstract: Recently, by employing intra-vital confocal microscopy, we demonstrated that platelets expose phosphatidylserine (PS) and fibrin accumulate only in the center of the thrombus but not in its periphery. To address the question how exposure of platelet anionic phospholipids is regulated within the thrombus, an in-vitro experiment using diluted platelet-rich plasma was employed, in which the fibrin network was formed in the presence of platelets, and PS exposure on the platelet surface was analyzed using Confocal Laser Scanning Microscopy. Almost all platelets exposed PS after treatment with tissue factor, thrombin or ionomycin. Argatroban abrogated fibrin network formation in all samples, however, platelet PS exposure was inhibited only in tissue factor- and thrombin-treated samples but not in ionomycin-treated samples. FK633, an α(IIb)β₃ antagonist, and cytochalasin B impaired platelet binding to the fibrin scaffold and significantly reduced PS exposure evoked by thrombin. Gly-Pro-Arg-Pro amide abrogated not only fibrin network formation, but also PS exposure on platelets without suppressing platelet binding to fibrin/fibrinogen. These results suggest that outside-in signals in platelets generated by their binding to the rigid fibrin network are essential for PS exposure after thrombin treatment.
authors: Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors: Tomasz
authors: T
authors: Brzoska
authors: Yuko
authors: Y
authors: Suzuki
authors: Hideo
authors: H
authors: Mogami
authors: Hideto
authors: H
authors: Sano
authors: Tetsumei
authors: T
authors: Urano
mesh_terms: D001777:Blood Coagulation / Q000502:physiology*; D001792:Blood Platelets / Q000378:metabolism*; D003571:Cytochalasin B / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D005337:Fibrin / Q000378:metabolism*; D006801:Humans; D018613:Microscopy, Confocal / Q000379:methods; D009842:Oligopeptides / Q000494:pharmacology; D010718:Phosphatidylserines / Q000378:metabolism; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013917:Thrombin / Q000378:metabolism*
chemical_list: D004151:Dipeptides; D009842:Oligopeptides; D010718:Phosphatidylserines; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C103087:((4-(4-amidinophenoxy)butanoyl)aspartyl)valine; D003571:Cytochalasin B; C034585:glycyl-prolyl-arginyl-proline; D005337:Fibrin; D013917:Thrombin
references: Blood. 1994 Sep 15;84(6):1857-65
references: 8080992
references: Pflugers Arch. 2008 Sep;456(6):1239-51
references: 18553102
references: Nature. 2010 Dec 9;468(7325):834-8
references: 21107324
references: Am Heart J. 2006 Jun;151(6):1131-8
references: 16781211
references: Anesth Analg. 2009 May;108(5):1433-46
references: 19372317
references: Thromb Haemost. 2001 Jul;86(1):413-9
references: 11487032
references: Blood. 1998 Nov 15;92(10):3675-83
references: 9808561
references: Thromb Haemost. 2002 Aug;88(2):186-93
references: 12195687
references: Thromb Haemost. 2001 Jun;85(6):958-65
references: 11434702
references: J Biol Chem. 1990 Jul 25;265(21):12267-71
references: 2373693
references: Arterioscler Thromb Vasc Biol. 2008 Mar;28(3):403-12
references: 18174460
references: Cell Mol Life Sci. 2007 Apr;64(7-8):999-1008
references: 17372676
references: Biochim Biophys Acta. 2004 Mar 22;1636(2-3):119-28
references: 15164759
references: Am J Physiol Heart Circ Physiol. 2001 Sep;281(3):H1156-62
references: 11514282
references: J Biol Chem. 2001 Apr 27;276(17):13975-81
references: 11278919
references: Blood. 1993 May 15;81(10):2554-65
references: 8490169
references: Am J Pathol. 2002 Jan;160(1):329-37
references: 11786426
references: J Biol Chem. 1990 Oct 15;265(29):17420-3
references: 2145274
references: J Biol Chem. 1989 May 15;264(14):7944-9
references: 2524476
references: Nature. 1962 Jun 9;194:927-9
references: 13871375
references: Neurochem Int. 2010 Apr;56(5):711-9
references: 20170696
references: Br J Haematol. 1972 Feb;22(2):193-204
references: 4333433
references: Biochim Biophys Acta. 1980 Jun 6;598(3):575-87
references: 6770901
references: Blood. 1998 Apr 15;91(8):2645-57
references: 9531572
references: J Clin Invest. 1996 Aug 1;98(3):863-74
references: 8698879
references: Cell Calcium. 1993 May;14(5):359-72
references: 8519060
references: J Clin Invest. 2005 Dec;115(12):3363-9
references: 16322781
references: Thromb Haemost. 2001 Oct;86(4):1065-9
references: 11686325
references: J Thromb Haemost. 2007 Mar;5(3):560-70
references: 17155950
references: Thromb Res. 1999 Jul 1;95(1):19-29
references: 10403683
references: Cell Mol Life Sci. 2012 Oct;69(20):3481-92
references: 22669259
references: Chem Pharm Bull (Tokyo). 1993 May;41(5):975-7
references: 8339344
references: Blood. 1997 Mar 1;89(5):1599-611
references: 9057642
references: J Biol Chem. 1997 Feb 21;272(8):5360-6
references: 9030612
references: Proc Natl Acad Sci U S A. 1978 Jul;75(7):3085-9
references: 277910
references: Proc Natl Acad Sci U S A. 1982 Jun;79(12):3711-5
references: 6954514
references: J Biol Chem. 1996 Mar 22;271(12):7004-11
references: 8636130
references: Circ Res. 1990 Oct;67(4):941-7
references: 2208617
references: Blood. 1997 Feb 15;89(4):1121-32
references: 9028933
references: Biochemistry. 1998 Feb 10;37(6):1640-5
references: 9484235