title: The development of inflammatory joint disease is attenuated in mice expressing the anticoagulant prothrombin mutant W215A/E217A.
abstract: Thrombin is a positive mediator of thrombus formation through the proteolytic activation of protease-activated receptors (PARs), fibrinogen, factor XI (fXI), and other substrates, and a negative regulator through activation of protein C, a natural anticoagulant with anti-inflammatory/cytoprotective properties. Protease-engineering studies have established that 2 active-site substitutions, W215A and E217A (fII(WE)), result in dramatically reduced catalytic efficiency with procoagulant substrates while largely preserving thrombomodulin (TM)-dependent protein C activation. To explore the hypothesis that a prothrombin variant favoring antithrombotic pathways would be compatible with development but limit inflammatory processes in vivo, we generated mice carrying the fII(WE) mutations within the endogenous prothrombin gene. Unlike fII-null embryos, fII(WE/WE) mice uniformly developed to term. Nevertheless, these mice ultimately succumbed to spontaneous bleeding events shortly after birth. Heterozygous fII(WT/WE) mice were viable and fertile despite a shift toward an antithrombotic phenotype exemplified by prolonged tail-bleeding times and times-to-occlusion after FeCl₃ vessel injury. More interestingly, prothrombin(WE) expression significantly ameliorated the development of inflammatory joint disease in mice challenged with collagen-induced arthritis (CIA). The administration of active recombinant thrombin(WE) also suppressed the development of CIA in wild-type mice. These studies provide a proof-of-principle that pro/thrombin variants engineered with altered substrate specificity may offer therapeutic opportunities for limiting inflammatory disease processes.
authors: Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors: Matthew J
authors: MJ
authors: Flick
authors: Anil K
authors: AK
authors: Chauhan
authors: Malinda
authors: M
authors: Frederick
authors: Kathryn E
authors: KE
authors: Talmage
authors: Keith W
authors: KW
authors: Kombrinck
authors: Whitney
authors: W
authors: Miller
authors: Eric S
authors: ES
authors: Mullins
authors: Joseph S
authors: JS
authors: Palumbo
authors: Xunzhen
authors: X
authors: Zheng
authors: Naomi L
authors: NL
authors: Esmon
authors: Charles T
authors: CT
authors: Esmon
authors: Sherry
authors: S
authors: Thornton
authors: Ann
authors: A
authors: Becker
authors: Leslie A
authors: LA
authors: Pelc
authors: Enrico
authors: E
authors: Di Cera
authors: Denisa D
authors: DD
authors: Wagner
authors: Jay L
authors: JL
authors: Degen
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001169:Arthritis, Experimental / Q000235:genetics / Q000378:metabolism*; D006470:Hemorrhage / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D008817:Mice, Mutant Strains; D020125:Mutation, Missense; D011486:Protein C / Q000235:genetics / Q000378:metabolism; D011516:Prothrombin / Q000235:genetics / Q000378:metabolism*
chemical_list: D011486:Protein C; D011516:Prothrombin