title: Thrombotic Role of Blood and Endothelial Cells in Uremia through Phosphatidylserine Exposure and Microparticle Release.
abstract: The mechanisms contributing to an increased risk of thrombosis in uremia are complex and require clarification. There is scant morphological evidence of membrane-dependent binding of factor Xa (FXa) and factor Va (FVa) on endothelial cells (EC) in vitro. Our objectives were to confirm that exposed phosphatidylserine (PS) on microparticle (MP), EC, and peripheral blood cell (PBC) has a prothrombotic role in uremic patients and to provide visible and morphological evidence of PS-dependent prothrombinase assembly in vitro. We found that uremic patients had more circulating MP (derived from PBC and EC) than controls. Additionally, patients had more exposed PS on their MPs and PBCs, especially in the hemodialysis group. In vitro, EC exposed more PS in uremic toxins or serum. Moreover, reconstitution experiments showed that at the early stages, PS exposure was partially reversible. Using confocal microscopy, we observed that PS-rich membranes of EC and MP provided binding sites for FVa and FXa. Further, exposure of PS in uremia resulted in increased generation of FXa, thrombin, and fibrin and significantly shortened coagulation time. Lactadherin, a protein that blocks PS, reduced 80% of procoagulant activity on PBC, EC, and MP. Our results suggest that PBC and EC in uremic milieu are easily injured or activated, which exposes PS and causes a release of MP, providing abundant procoagulant membrane surfaces and thus facilitating thrombus formation. Blocking PS binding sites could become a new therapeutic target for preventing thrombosis.
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.|Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Gao
authors.affiliation: Department of Gastrointestinal Oncology, The Third Hospital, Harbin Medical University, Harbin, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Xie
authors.affiliation: Department of Nephrology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Chengyuan
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China.
authors.forename: Ruishuang
authors.initials: R
authors.lastname: Ma
authors.affiliation: Department of general surgery, The fifth Hospital, Harbin Medical University, Harbin, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Dong
authors.affiliation: Department of Cardiology, The Second Hospital, Harbin Medical University, Harbin, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Meng
authors.affiliation: Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Si
authors.affiliation: Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Medicine Departments, VA Boston Healthcare System, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America.
authors.forename: Valerie
authors.initials: V
authors.lastname: Novakovic
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, The Second Hospital, Harbin Medical University, Harbin, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Kou
authors.affiliation: Department of Cardiology, The Second Hospital, Harbin Medical University, Harbin, China.
authors.forename: Yayan
authors.initials: Y
authors.lastname: Bi
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Baoxin
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Gastrointestinal Oncology, The Third Hospital, Harbin Medical University, Harbin, China.
authors.forename: Rujuan
authors.initials: R
authors.lastname: Xie
authors.affiliation: Medicine Departments, VA Boston Healthcare System, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America.
authors.forename: Gary E
authors.initials: GE
authors.lastname: Gilbert
authors.affiliation: Department of Medical Laboratory Science and Technology, Harbin Medical University-Daqing, Daqing, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.|Medicine Departments, VA Boston Healthcare System, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America.
authors.forename: Jialan
authors.initials: J
authors.lastname: Shi
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001777:Blood Coagulation; D002417:Cattle; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D003029:Coagulants; D042783:Endothelial Cells / Q000378:metabolism*; D015951:Factor Xa / Q000378:metabolism; D005260:Female; D005337:Fibrin / Q000378:metabolism; D005434:Flow Cytometry; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000737:chemistry; D018613:Microscopy, Confocal; D008875:Middle Aged; D008894:Milk Proteins / Q000737:chemistry; D010718:Phosphatidylserines / Q000737:chemistry*; D013917:Thrombin / Q000378:metabolism; D013925:Thromboplastin / Q000378:metabolism; D013927:Thrombosis / Q000097:blood* / Q000378:metabolism* / Q000517:prevention & control; D014511:Uremia / Q000097:blood*
chemical_list: D003029:Coagulants; D008562:Membrane Glycoproteins; D008894:Milk Proteins; C106215:PAS-6-7 glycoprotein, Bos taurus; D010718:Phosphatidylserines; D005337:Fibrin; D013925:Thromboplastin; D013917:Thrombin; D015951:Factor Xa