title: The C-terminal CGHC motif of protein disulfide isomerase supports thrombosis.
abstract: Protein disulfide isomerase (PDI) has two distinct CGHC redox-active sites; however, the contribution of these sites during different physiologic reactions, including thrombosis, is unknown. Here, we evaluated the role of PDI and redox-active sites of PDI in thrombosis by generating mice with blood cells and vessel wall cells lacking PDI (Mx1-Cre Pdifl/fl mice) and transgenic mice harboring PDI that lacks a functional C-terminal CGHC motif [PDI(ss-oo) mice]. Both mouse models showed decreased fibrin deposition and platelet accumulation in laser-induced cremaster arteriole injury, and PDI(ss-oo) mice had attenuated platelet accumulation in FeCl3-induced mesenteric arterial injury. These defects were rescued by infusion of recombinant PDI containing only a functional C-terminal CGHC motif [PDI(oo-ss)]. PDI infusion restored fibrin formation, but not platelet accumulation, in eptifibatide-treated wild-type mice, suggesting a direct role of PDI in coagulation. In vitro aggregation of platelets from PDI(ss-oo) mice and PDI-null platelets was reduced; however, this defect was rescued by recombinant PDI(oo-ss). In human platelets, recombinant PDI(ss-oo) inhibited aggregation, while recombinant PDI(oo-ss) potentiated aggregation. Platelet secretion assays demonstrated that the C-terminal CGHC motif of PDI is important for P-selectin expression and ATP secretion through a non-αIIbβ3 substrate. In summary, our results indicate that the C-terminal CGHC motif of PDI is important for platelet function and coagulation.
authors.forename: Junsong
authors.initials: J
authors.lastname: Zhou
authors.forename: Yi
authors.initials: Y
authors.lastname: Wu
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.forename: Lubica
authors.initials: L
authors.lastname: Rauova
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Hayes
authors.forename: Mortimer
authors.initials: M
authors.lastname: Poncz
authors.forename: David W
authors.initials: DW
authors.lastname: Essex
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001777:Blood Coagulation; D001792:Blood Platelets / Q000201:enzymology* / Q000473:pathology; D002712:Chlorides / Q000494:pharmacology; D005337:Fibrin / Q000235:genetics / Q000378:metabolism; D006801:Humans; D058085:Iron Compounds / Q000494:pharmacology; D051379:Mice; D008822:Mice, Transgenic; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism; D010974:Platelet Aggregation; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D013927:Thrombosis / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
chemical_list: D002712:Chlorides; D058085:Iron Compounds; D019007:P-Selectin; D005337:Fibrin; D019704:Protein Disulfide-Isomerases