title: Functional difference between membrane-bound and soluble human thrombomodulin.
abstract: BACKGROUND
  For successful xenotransplantation, in addition to α1,3-galactosyltransferase gene-knockout and human complement regulatory protein (CD46, CD55, CD59) gene insertion, cloned pigs expressing human thrombomodulin (hTM) have been produced to solve the problem of molecular incompatibility in their coagulation system. Recombinant soluble hTM (S-hTM) which has been recently approved for treatment of disseminated intravascular coagulation might be potentially available. The purpose of this study is to examine the functional difference in endothelial cells between membrane-bound hTM (MB-hTM) and S-hTM and to elucidate effective strategy using both types of hTM.
  
  
  METHODS
  The following factors regarding coagulation and inflammation were compared between hTM-expressing pig aortic endothelial cells (PAEC) derived from cloned pig and nontransgenic PAEC in the presence of S-hTM under tumor necrosis factor-α-activated conditions; (i) clotting time (ii) pig tissue factor (TF), (iii) pig E-selectin, (iv) direct prothrombinase activity, (v) activated protein C (APC), and (vi) prothrombinase activity.
  
  
  RESULTS
  The MB-hTM significantly suppressed the expression of pig TF and E-selectin and direct prothrombinase activity in tumor necrosis factor-α-activated PAEC, suggesting strong anti-inflammatory effect, compared to S-hTM. In contrast, S-hTM had more potent capacity to inhibit thrombin generation and to produce APC than MB-hTM, although MB-hTM had the same level of capacity as human endothelial cells.
  
  
  CONCLUSIONS
  It was speculated that S-hTM treatment would be of assistance during high-risk periods for excessive thrombin formation (e.g., ischemia reperfusion injury or severe infection/rejection). Considering the properties of MB-hTM exhibiting anti-inflammatory function as well as APC production, hTM-expressing cloned pigs might be indispensible to long-term stabilization of graft endothelial cells.
authors: 1 Department of Transplant Immunology, Nagoya University Graduate School of Medicine, Nagoya, Japan. 2 Prime Tech Ltd, Tsuchiura, Japan. 3 Department of Developmental Biology, National Institute of Agrobiological Sciences, Tsukuba, Japan. 4 Department of Transfusion Medicine, Nagoya University School of Medicine, Nagoya, Japan. 5 Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan. 6 Department Animal Science and Resources, Nihon University of College of Bioresource Sciences, Fujisawa, Japan. 7 Department of Surgery II, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Yuko
authors: Y
authors: Miwa
authors: Satoko
authors: S
authors: Yazaki
authors: Masaki
authors: M
authors: Iwamoto
authors: Shunichi
authors: S
authors: Suzuki
authors: Kenta
authors: K
authors: Iwasaki
authors: Masataka
authors: M
authors: Haneda
authors: Koji
authors: K
authors: Yamamoto
authors: Shoichi
authors: S
authors: Maruyama
authors: Akira
authors: A
authors: Onishi
authors: Takaaki
authors: T
authors: Kobayashi
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000925:Anticoagulants / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects; D001780:Blood Coagulation Tests; D002462:Cell Membrane / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D019040:E-Selectin / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism; D011486:Protein C / Q000378:metabolism; D012995:Solubility; D013552:Swine / Q000235:genetics; D018180:Thrombomodulin / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D013925:Thromboplastin / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000925:Anticoagulants; D019040:E-Selectin; D018836:Inflammation Mediators; D011486:Protein C; C546931:THBD protein, human; D018180:Thrombomodulin; D014409:Tumor Necrosis Factor-alpha; D013925:Thromboplastin