Haemostatic, fibrinolytic and inflammatory profiles in West Highland white terriers with canine idiopathic pulmonary fibrosis and controls

Abstract Background Canine idiopathic pulmonary fibrosis (CIPF) is a progressive interstitial lung disease mainly affecting old West Highland white terriers (WHWTs). The aetiology of CIPF is currently unknown and pathogenesis poorly understood. A genetic basis is strongly suspected based on the breed predisposition. CIPF shares clinical and pathological features with human IPF. In human IPF, coagulation disorders favouring a local and systemic pro-thrombotic state have been demonstrated in association with disease severity and outcome. The aim of this study was to compare the systemic haemostatic, fibrinolytic and inflammatory profiles of WHWTs affected with CIPF with breed-matched controls (CTRLs). Additionally, data collected in both groups were interpreted with regard to the reference intervals (when available) to assess possible pro-thrombotic features of the WHWT breed that may be related to CIPF predisposition. A total of 14 WHWTs affected with CIPF and 20 CTRLs were included. Results WHWTs affected with CIPF had prolonged activated partial thromboplastine time in comparison with CTRLs (12.2 ± 0.9 s vs. 11.5 ± 0.7 s, P = 0.028), whereas results obtained in both groups were all within reference ranges. There was no significant difference between groups for the other factors assessed including plasmatic concentrations of fibrinogen, D-dimers concentration, antithrombin III activity, protein S and protein C activities, anti-factor Xa activity, activated protein C ratio, serum C-reactive protein concentration, and rotational thromboelastometry indices. Platelet count and plasmatic fibrinogen concentration were found to be above the upper limit of the reference range in almost half of the WHWTs included, independently of the disease status. Conclusions Results of this study provide no clear evidence of an altered systemic haemostatic, fibrinolytic or inflammatory state in WHWTs affected with CIPF compared with CTRLs. The higher platelet counts and fibrinogen concentrations found in the WHWT breed may serve as predisposing factors for CIPF or simply reflect biological variation in this breed.

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Plasma protein S contains zinc essential for efficient activated protein C‐independent anticoagulant activity and binding to factor Xa, but not for efficient binding to tissue factor pathway inhibitor

The FASEB Journal ◽

10.1096/fj.08-123174 ◽

2009 ◽

Vol 23 (7) ◽

pp. 2244-2253 ◽

Cited By ~ 24

Author(s):

Mary J. Heeb ◽

Duane Prashun ◽

John H. Griffin ◽

Bonno N. Bouma

Keyword(s):

Tissue Factor ◽

Plasma Protein ◽

Protein C ◽

Tissue Factor Pathway Inhibitor ◽

Anticoagulant Activity ◽

Activated Protein C ◽

Factor Xa ◽

Protein S ◽

Tissue Factor Pathway

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Implication of protein S thrombin-sensitive region with membrane binding via conformational changes in the γ-carboxyglutamic acid-rich domain

Biochemical Journal ◽

10.1042/bj3600499 ◽

2001 ◽

Vol 360 (2) ◽

pp. 499-506 ◽

Cited By ~ 4

Author(s):

Delphine BORGEL ◽

Pascale GAUSSEM ◽

Christiane GARBAY ◽

Christilla BACHELOT-LOZA ◽

Tahar KAABACHE ◽

...

Keyword(s):

Conformational Changes ◽

Protein C ◽

Anticoagulant Activity ◽

Activated Protein C ◽

Factor Xa ◽

Protein S ◽

Sensitive Region ◽

Rich Domain ◽

Activated Platelets ◽

Carboxyglutamic Acid

In the vitamin K-dependent protein family, only protein S (PS) contains a thrombin-sensitive region (TSR), located between the domain containing the γ-carboxyglutamic acid and the first epidermal growth factor-like domain. To better define the role of TSR in the PS molecule, we expressed a recombinant human PS (rHPS) and its analogue lacking TSR (rTSR-less), and prepared factor Xa- and thrombin-cleaved rHPS. A peptide reproducing TSR (TSR-peptide) was also synthesized in an attempt to obtain direct evidence of the domain involvement in PS anticoagulant activity. In a coagulation assay, both rTSR-less and factor Xa-cleaved PS were devoid of activated protein C cofactor activity. The TSR-peptide did not inhibit rHPS activity, showing that TSR must be embedded in the native protein to promote interaction with activated protein C. The binding of rHPS to activated platelets and to phospholipid vesicles was not modified after factor Xa- or thrombin-mediated TSR cleavage, whereas the binding of rTSR-less was markedly reduced. This suggested a role for TSR in conferring to PS a strong affinity for phospholipid membranes. TSR-peptide did not directly bind to activated platelets or compete with rHPS for phospholipid binding. The results of the present study show that TSR may not interact directly with membranes, but probably constrains the γ-carboxyglutamic acid-rich domain in a conformation allowing optimal interaction with phospholipids.

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Regulation Of Bovine Activated Protein C By Protein S: The Role Of The Cofactor Protein In Species Specificity

10.1055/s-0038-1652134 ◽

1981 ◽

Author(s):

F J Walker

Keyword(s):

Protein C ◽

Anticoagulant Activity ◽

Activated Protein C ◽

Factor Xa ◽

Protein S ◽

Species Specificity ◽

Rabbit Plasma ◽

Factor Va ◽

Bovine Plasma ◽

Species Specific

The anticoagulant activity of activated Protein C has been observed to be species specific. This could be due either to the inability of the bovine enzyme to recognize its substrate, Factor Va, in non-bovine plasmas, or the absence of cofactor-Protein S, a protein that has been shown to be necessary for the maximum expression of the anticoagulant activity of activated Protein C. Activated Protein C was found to be an effective inhibitor of Factor Xa-initiated clotting of bovine plasma, but without activity in either human or rabbit plasma. Human and rabbit plasma supplemented with bovine Protein S was sensitive to the anticoagulant activity of activated Protein C. Neither rabbit nor human plasma contained bovine activated Protein C cofactor activity as measured by the enhancement of bovine activated Protein C-catalyzed inactivation of Factor Va. However, bovine activated Protein C was able to inactivate both human and rabbit Factor Va. The inactivation of both of these proteins could be stimulated by the addition of bovine Protein S. These results indicate that the species specificity of bovine activated Protein C is due to the absence of a cofactor protein in non-bovine plasma that will interact with the bovine enzyme. Secondly, these findings further confirm that Protein S is required for the maximal expression of the anticoagulant activity of activated Protein C.

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Resistance to activated protein C, the FV: Q506 allele, and venous thrombosis

Hämostaseologie ◽

10.1055/s-0038-1655322 ◽

1998 ◽

Vol 18 (01) ◽

pp. 1-10

Author(s):

A. Hillarp ◽

S. Rosen ◽

B. Zöller ◽

B. Dahlbäck

Keyword(s):

Venous Thrombosis ◽

Protein C ◽

Antithrombin Iii ◽

Single Point ◽

Activated Protein C ◽

Factor Xa ◽

Protein S ◽

Single Point Mutation ◽

Factor V ◽

Endothelial Cell Surface

SummaryVitamin K-dependent protein C is an important regulator of blood coagulation. After its activation on the endothelial cell surface by thrombin bound to thrombomodulin, it cleaves and inactivates procoagulant cofactors Va and Villa, protein S and intact factor V working as cofactors. Until recently, genetic defects of protein C or protein S were, together with antithrombin III deficiency, the established major causes of familial venous thromboembolism, but they were found in fewer than 5-10% of patients with thrombosis. In 1993, inherited resistance to activated protein C (APC) was described as a major risk factor for venous thrombosis. It is found in up to 60% of patients with venous thrombosis. In more than 90% of cases, the molecular background for the APC resistance is a single point mutation in the factor V gene, which predicts substitution of an arginine (R) at position 506 by a glutamine (Q). Mutated factor V (FV: Q506) is activated by thrombin or factor Xa in normal way, but impaired inactivation of mutated factor Va by APC results in life-long hypercoagulability. The prevalence of the FV:Q506 allele in the general population of Western countries varies between 2 and 15%, whereas it is not found in several other populations with different ethnic backgrounds. Owing to the high prevalence of FV:Q506 in Western populations, it occasionally occurs in patients with deficiency of protein S, protein C, or antithrombin III. Individuals with combined defects suffer more severely from thrombosis, and often at a younger age, than those with single defects, suggesting severe thrombophilia to be a multigenetic disease.

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Effects of Protein S and Factor Xa on Peptide Bond Cleavages during Inactivation of Factor Va and Factor VaR506Qby Activated Protein C

Journal of Biological Chemistry ◽

10.1074/jbc.270.46.27852 ◽

1995 ◽

Vol 270 (46) ◽

pp. 27852-27858 ◽

Cited By ~ 155

Author(s):

Jan Rosing ◽

Lico Hoekema ◽

Gerry A. F. Nicolaes ◽

M. Christella L. G. D. Thomassen ◽

H. Coenraad Hemker ◽

...

Keyword(s):

Protein C ◽

Activated Protein C ◽

Factor Xa ◽

Protein S ◽

Peptide Bond ◽

Factor Va

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Pharmacokinetics of activated protein C in guinea pigs

Blood ◽

10.1182/blood.v77.10.2174.2174 ◽

1991 ◽

Vol 77 (10) ◽

pp. 2174-2184 ◽

Cited By ~ 2

Author(s):

H Jr Berger ◽

CG Kirstein ◽

CL Orthner

Keyword(s):

Protease Inhibitors ◽

Active Site ◽

Guinea Pigs ◽

Protein C ◽

Dose Range ◽

Activated Protein C ◽

Factor Xa ◽

Protein S

Abstract Protein C is a vitamin K-dependent zymogen of the serine protease, activated protein C (APC), an important regulatory enzyme in hemostasis. In view of the potential of human APC as an anticoagulant and profibrinolytic agent, the pharmacokinetics and tissue distribution of APC were studied in guinea pigs. The plasma elimination of a trace dose of 125I-APC was biphasic following an initial rapid elimination of approximately 15% of the injected dose within 1 to 2 minutes. This rapid removal of 125I-APC from the circulation was found to be a result of an association with the liver regardless of the route of injection. Essentially identical results were obtained with active site-blocked forms of APC generated with either diisopropylfluorophosphate or D- phenylalanyl-L-prolyl-L-arginine chloromethyl ketone, which indicates that the active site was not essential for the liver association. Accumulation of all three forms of APC in the liver peaked at 30 minutes and then declined as increasing amounts of degraded radiolabeled material appeared in the gastrointestinal tract and urine. Removal of the gamma-carboxyglutamic acid (gla) domain of diisopropylphosphoryl-APC resulted in a 50% reduction in the association with liver and an accumulation in the kidneys. Protein C and protein S were cleared from the circulation at rates approximately one-half and one-fourth, respectively, that of APC. Both in vitro and in vivo, APC was found to form complexes with protease inhibitors present in guinea pig plasma. Complex formation resulted in a more rapid disappearance of the enzymatic activity of APC than elimination of the protein moiety. These findings indicate two distinct mechanisms for the elimination of APC. One mechanism involves reaction with plasma protease inhibitors and subsequent elimination by specific hepatic receptors. The other mechanism involves the direct catabolism of APC by the liver via a pathway that is nonsaturable over a substantial dose range and independent of the active site. This pattern of elimination is distinctly different from that observed with the homologous coagulation enzymes thrombin, factor IXa, and factor Xa.

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Effects of Factor Xa and Protein S on the Individual Activated Protein C-mediated Cleavages of Coagulation Factor Va

Journal of Biological Chemistry ◽

10.1074/jbc.m606441200 ◽

2006 ◽

Vol 281 (42) ◽

pp. 31486-31494 ◽

Cited By ~ 22

Author(s):

Eva A. Norstrøm ◽

Sinh Tran ◽

Mårten Steen ◽

Björn Dahlbäck

Keyword(s):

Protein C ◽

Activated Protein C ◽

Factor Xa ◽

Coagulation Factor ◽

Protein S ◽

Factor Va ◽

The Individual

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Pharmacokinetics of activated protein C in guinea pigs

Blood ◽

10.1182/blood.v77.10.2174.bloodjournal77102174 ◽

1991 ◽

Vol 77 (10) ◽

pp. 2174-2184

Author(s):

H Jr Berger ◽

CG Kirstein ◽

CL Orthner

Keyword(s):

Protease Inhibitors ◽

Active Site ◽

Guinea Pigs ◽

Protein C ◽

Dose Range ◽

Activated Protein C ◽

Factor Xa ◽

Protein S

Protein C is a vitamin K-dependent zymogen of the serine protease, activated protein C (APC), an important regulatory enzyme in hemostasis. In view of the potential of human APC as an anticoagulant and profibrinolytic agent, the pharmacokinetics and tissue distribution of APC were studied in guinea pigs. The plasma elimination of a trace dose of 125I-APC was biphasic following an initial rapid elimination of approximately 15% of the injected dose within 1 to 2 minutes. This rapid removal of 125I-APC from the circulation was found to be a result of an association with the liver regardless of the route of injection. Essentially identical results were obtained with active site-blocked forms of APC generated with either diisopropylfluorophosphate or D- phenylalanyl-L-prolyl-L-arginine chloromethyl ketone, which indicates that the active site was not essential for the liver association. Accumulation of all three forms of APC in the liver peaked at 30 minutes and then declined as increasing amounts of degraded radiolabeled material appeared in the gastrointestinal tract and urine. Removal of the gamma-carboxyglutamic acid (gla) domain of diisopropylphosphoryl-APC resulted in a 50% reduction in the association with liver and an accumulation in the kidneys. Protein C and protein S were cleared from the circulation at rates approximately one-half and one-fourth, respectively, that of APC. Both in vitro and in vivo, APC was found to form complexes with protease inhibitors present in guinea pig plasma. Complex formation resulted in a more rapid disappearance of the enzymatic activity of APC than elimination of the protein moiety. These findings indicate two distinct mechanisms for the elimination of APC. One mechanism involves reaction with plasma protease inhibitors and subsequent elimination by specific hepatic receptors. The other mechanism involves the direct catabolism of APC by the liver via a pathway that is nonsaturable over a substantial dose range and independent of the active site. This pattern of elimination is distinctly different from that observed with the homologous coagulation enzymes thrombin, factor IXa, and factor Xa.

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