title: Impaired thrombin generation in Reelin-deficient mice: a potential role of plasma Reelin in hemostasis.
abstract: BACKGROUND
  Reelin is a large extracellular glycoprotein that is present in the peripheral blood. That Reelin interacts with the coagulation components and elicits a functional role in hemostasis has not yet been elucidated.
  
  
  OBJECTIVE
  The hemostatic activity of Reelin is investigated and defined in this study.
  
  
  METHODS
  The interplay of Reelin with coagulation components was elucidated by far-Western and liposome/platelet binding assays. In vivo and ex vivo hemostasis-related analyses of Reelin-deficient mice and plasma were also performed.
  
  
  RESULTS
  Reelin interacted with the liposomes containing phosphatidylserine (PS) or phosphatidylcholine. Instead of interacting with known Reelin receptors (ApoE receptor 2, very low density lipoprotein receptor and integrin β1), Reelin interacted with PS of the activated platelets. The interaction between Reelin and the coagulation factors of thrombin and FXa was also demonstrated with the Kd of 11.7 and 21.2 nm, respectively. Reelin-deficient mice displayed a prolonged bleeding time and an increase in rebleeding rate. Despite the fact that Reelin deficiency had no significant effect on the clotting time of prothrombin and activated partial thromboplastin time, the fibrin clot formation was abnormal and the fibrin clot structure was relatively loosened with reduced clot strength. Abnormal fibrinogen expression did not account for the hemostatic defects associated with Reelin deficiency. Instead, thrombin generation was impaired concomitant with an altered prothrombin cleavage pattern.
  
  
  CONCLUSIONS
  By interacting with platelet phospholipids and the coagulation factors, thrombin and FXa, Reelin plays a selective role in coagulation activation, leading to thrombin generation and formation of a normal fibrin clot.
authors.affiliation: Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Kweishan, Taoyuan, Taiwan.
authors.forename: W-L
authors.initials: WL
authors.lastname: Tseng
authors.forename: T-H
authors.initials: TH
authors.lastname: Chen
authors.forename: C-C
authors.initials: CC
authors.lastname: Huang
authors.forename: Y-H
authors.initials: YH
authors.lastname: Huang
authors.forename: C-F
authors.initials: CF
authors.lastname: Yeh
authors.forename: H-J
authors.initials: HJ
authors.lastname: Tsai
authors.forename: H-Y
authors.initials: HY
authors.lastname: Lee
authors.forename: C-Y
authors.initials: CY
authors.lastname: Kao
authors.forename: S-W
authors.initials: SW
authors.lastname: Lin
authors.forename: H-R
authors.initials: HR
authors.lastname: Liao
authors.forename: J-C
authors.initials: JC
authors.lastname: Cheng
authors.forename: C-P
authors.initials: CP
authors.lastname: Tseng
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000737:chemistry; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000737:chemistry; D001792:Blood Platelets / Q000166:cytology; D015816:Cell Adhesion Molecules, Neuronal / Q000097:blood* / Q000235:genetics*; D016326:Extracellular Matrix Proteins / Q000097:blood* / Q000235:genetics*; D015951:Factor Xa / Q000737:chemistry; D005337:Fibrin / Q000737:chemistry; D005340:Fibrinogen / Q000737:chemistry; D005838:Genotype; D006023:Glycoproteins / Q000737:chemistry; D006487:Hemostasis; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D051379:Mice; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000097:blood* / Q000235:genetics*; D010314:Partial Thromboplastin Time; D010713:Phosphatidylcholines / Q000737:chemistry; D010718:Phosphatidylserines / Q000737:chemistry; D015539:Platelet Activation; D010974:Platelet Aggregation; D011485:Protein Binding; D011517:Prothrombin Time; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000097:blood* / Q000235:genetics*; D013917:Thrombin / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D017304:Annexin A5; D001779:Blood Coagulation Factors; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D008055:Lipids; D008081:Liposomes; D009419:Nerve Tissue Proteins; D010713:Phosphatidylcholines; D010718:Phosphatidylserines; D000091042:Reelin Protein; D005337:Fibrin; D005340:Fibrinogen; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases; D013917:Thrombin; D015951:Factor Xa
keywords: hemostasis; phosphatidylserines; prothrombinase; reelin protein; thrombin