Effects of Plasma Kallikrein Specific Inhibitor and Active-site Blocked Factor VIIa on the Pulmonary Vascular Injury Induced by Endotoxin in Rats

1997 ◽  
Vol 78 (04) ◽  
pp. 1209-1214 ◽  
Author(s):  
Mitsuhiro Uchiba ◽  
Kenji Okajima ◽  
Kazunori Murakami ◽  
Hiroaki Okabe ◽  
Shosuke Okamoto ◽  
...  
Keyword(s):  
Vascular Injury ◽  
Active Site ◽  
Factor Viia ◽  
Specific Inhibitor ◽  
Coagulation System ◽  
Plasma Kallikrein ◽  
Extrinsic Pathway ◽  
E Coli ◽  
Intravascular Coagulation

SummaryThe acute respiratory distress syndrome (ARDS) is a serious complication of sepsis. To evaluate the role of the coagulation system in the pathogenesis of ARDS in sepsis, we examined the effects of the administration of a synthetic plasma kallikrein specific inhibitor (PKSI) and of active-site blocked factor VIIa (DEGR-VIIa) on the pulmonary vascular injury induced by E. coli endotoxin (ET) in rats. Administration of PKSI prevented the pulmonary vascular injury induced by ET as well as pulmonary histological changes in animals administered ET, but it did not affect the intravascular coagulation. The opposite effect was seen with DEGR-VIIa, which prevented the intravascular coagulation but not the pulmonary vascular injury. PKSI did not inhibit the activation of the complement system induced by ET leading to the activation of neutrophils.Findings suggest that PKSI may prevent the pulmonary vascular injury induced by ET by inhibiting kallikrein, which activates the neutrophils. The intrinsic pathway of coagulation may be more important than the extrinsic pathway in the pulmonary vascular injury produced byET.

scholarly journals Engineering the substrate and inhibitor specificities of human coagulation Factor VIIa

2007 ◽  
Vol 405 (3) ◽  
pp. 429-438 ◽  
Author(s):  
Katrine S. Larsen ◽  
Henrik Østergaard ◽  
Jais R. Bjelke ◽  
Ole H. Olsen ◽  
Hanne B. Rasmussen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Substrate Specificity ◽  
Active Site ◽  
Factor Viia ◽  
Coagulation Factor ◽  
Combinatorial Libraries ◽  
Factor Vii ◽  
Activate Factor ◽  
Extrinsic Pathway

The remarkably high specificity of the coagulation proteases towards macromolecular substrates is provided by numerous interactions involving the catalytic groove and remote exosites. For FVIIa [activated FVII (Factor VII)], the principal initiator of coagulation via the extrinsic pathway, several exosites have been identified, whereas only little is known about the specificity dictated by the active-site architecture. In the present study, we have profiled the primary P4–P1 substrate specificity of FVIIa using positional scanning substrate combinatorial libraries and evaluated the role of the selective active site in defining specificity. Being a trypsin-like serine protease, FVIIa had P1 specificity exclusively towards arginine and lysine residues. In the S2 pocket, threonine, leucine, phenylalanine and valine residues were the most preferred amino acids. Both S3 and S4 appeared to be rather promiscuous, however, with some preference for aromatic amino acids at both positions. Interestingly, a significant degree of interdependence between the S3 and S4 was observed and, as a consequence, the optimal substrate for FVIIa could not be derived directly from a subsite-directed specificity screen. To evaluate the role of the active-site residues in defining specificity, a series of mutants of FVIIa were prepared at position 239 (position 99 in chymotrypsin), which is considered to be one of the most important residues for determining P2 specificity of the trypsin family members. This was confirmed for FVIIa by marked changes in primary substrate specificity and decreased rates of antithrombin III inhibition. Interestingly, these changes do not necessarily coincide with an altered ability to activate Factor X, demonstrating that inhibitor and macromolecular substrate selectivity may be engineered separately.

A Re-Appraisal of the Role of Blood Coagulation and Platelets in the Generalized Shwartzman Phenomenon

1966 ◽  
Vol 15 (03/04) ◽  
pp. 519-538 ◽  
Author(s):  
J Levin ◽  
E Beck
Keyword(s):  
Blood Coagulation ◽  
The State ◽  
Coagulation System ◽  
Renal Lesions ◽  
Intravascular Coagulation ◽  
Renal Glomeruli ◽  
Coagulation Mechanism ◽  
Shwartzman Phenomenon ◽  
Do So

SummaryThe role of intravascular coagulation in the production of the generalized Shwartzman phenomenon has been evaluated. The administration of endotoxin to animals prepared with Thorotrast results in activation of the coagulation mechanism with the resultant deposition of fibrinoid material in the renal glomeruli. Anticoagulation prevents alterations in the state of the coagulation system and inhibits development of the renal lesions. Platelets are not primarily involved. Platelet antiserum produces similar lesions in animals prepared with Thorotrast, but appears to do so in a manner which does not significantly involve intravascular coagulation.The production of adrenal cortical hemorrhage, comparable to that seen in the Waterhouse-Friderichsen syndrome, following the administration of endotoxin to animals that had previously received ACTH does not require intravascular coagulation and may not be a manifestation of the generalized Shwartzman phenomenon.

scholarly journals Immunodepletion of extrinsic pathway inhibitor sensitizes rabbits to endotoxin-induced intravascular coagulation and the generalized Shwartzman reaction

Blood ◽  
1991 ◽  
Vol 78 (6) ◽  
pp. 1496-1502 ◽  
Author(s):  
PM Sandset ◽  
BJ Warn-Cramer ◽  
SL Maki ◽  
SI Rapaport
Keyword(s):  
Factor Viia ◽  
Factor V ◽  
Activity Levels ◽  
Cell Surfaces ◽  
Extrinsic Pathway ◽  
Intravascular Coagulation ◽  
Disease States ◽  
Shwartzman Reaction ◽  
Thrombotic Complications

Abstract We have reported earlier that immunodepletion of extrinsic pathway inhibitor (EPI) sensitizes rabbits to disseminated intravascular coagulation (DIC) induced by infusing a low concentration of tissue factor (TF). We now describe the effect of immunodepletion of EPI in rabbits administered endotoxin. Cortisone-treated rabbits were administered anti-rabbit EPI immunoglobulin (IgG) or Fab fragments or were administered control nonimmune material before an injection of endotoxin. In four of seven rabbits administered anti-EPI, plasma EPI activity levels were reduced by 70% to 80% of initial levels for 6 to 8 hours. In these rabbits the endotoxin induced extensive DIC, as evidenced by substantial decreases in fibrinogen, factor V, factor VIII, and platelets, and gross hemorrhagic necrosis of the kidneys due to massive deposition of fibrin in the glomerular microcirculation (the generalized Shwartzman reaction). In three rabbits administered anti- EPI, plasma EPI levels were only transiently reduced. In these rabbits and in four rabbits administered nonimmune IgG or Fab, endotoxin induced minimal to moderate intravascular clotting and deposits of fibrin were not found in the glomerular capillaries. Because it is believed that TF expressed on monocytes triggers endotoxin-induced coagulation, these data are taken as evidence that EPI functions as a natural anticoagulant that can regulate factor VIIa/TF activity expressed on cell surfaces in vivo. They support a hypothesis that EPI prevents thrombotic complications that might otherwise result from exposure of blood to cytokine-induced generation of small amounts of TF on cell surfaces in many inflammatory and infectious disease states.

scholarly journals Plasma Kallikrein Contributes to Coagulation in the Absence of Factor XI by Activating Factor IX

2020 ◽  
Vol 40 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Mayken Visser ◽  
René van Oerle ◽  
Hugo ten Cate ◽  
Volker Laux ◽  
Nigel Mackman ◽  
...  
Keyword(s):  
Complex Formation ◽  
Ellagic Acid ◽  
Thrombin Generation ◽  
Factor Ix ◽  
Coagulation System ◽  
Plasma Kallikrein ◽  
Factor Xia ◽  
The Difference ◽  
Long Chain

Objectives: FXIa (factor XIa) induces clot formation, and human congenital FXI deficiency protects against venous thromboembolism and stroke. In contrast, the role of FXI in hemostasis is rather small, especially compared with FIX deficiency. Little is known about the cause of the difference in phenotypes associated with FIX deficiency and FXI deficiency. We speculated that activation of FIX via the intrinsic coagulation is not solely dependent on FXI(a; activated FXI) and aimed at identifying an FXI-independent FIX activation pathway. Approach and Results: We observed that ellagic acid and long-chain polyphosphates activated the coagulation system in FXI-deficient plasma, as could be demonstrated by measurement of thrombin generation, FIXa-AT (antithrombin), and FXa-AT complex levels, suggesting an FXI bypass route of FIX activation. Addition of a specific PKa (plasma kallikrein) inhibitor to FXI-deficient plasma decreased thrombin generation, prolonged activated partial thromboplastin time, and diminished FIXa-AT and FXa-AT complex formation, indicating that PKa plays a role in the FXI bypass route of FIX activation. In addition, FIXa-AT complex formation was significantly increased in F11 −/− mice treated with ellagic acid or long-chain polyphosphates compared with controls and this increase was significantly reduced by inhibition of PKa. Conclusions: We demonstrated that activation of FXII leads to thrombin generation via FIX activation by PKa in the absence of FXI. These findings may, in part, explain the different phenotypes associated with FIX and FXI deficiencies.

Inactivation of CD11b in a mouse transgenic model protects against sepsis-induced lung PMN infiltration and vascular injury

2005 ◽  
Vol 21 (2) ◽  
pp. 230-242 ◽  
Author(s):  
Xiao-Pei Gao ◽  
Qinghui Liu ◽  
Michael Broman ◽  
Dan Predescu ◽  
Randall S. Frey ◽  
...  
Keyword(s):  
Vascular Injury ◽  
Vascular Inflammation ◽  
Edema Formation ◽  
Cd11b Expression ◽  
E Coli ◽  
Transgenic Model ◽  
Microvessel Permeability ◽  
In Vivo Effects

To inactivate chronically the β2-integrin CD11b (Mac-1), we made a transgenic model in mice in which we expressed the CD11b antagonist polypeptide neutrophil inhibitory factor (NIF). Using these mice, we determined the in vivo effects of CD11b inactivation on polymorphonuclear leukocyte (PMN) function and acute lung injury (ALI) induced by Escherichia coli septicemia. In wild-type PMNs, CD11b expression was induced within 1 h after E. coli challenge, whereas this response was significantly reduced in NIF+/+ PMNs. Coimmunoprecipitation studies showed that NIF associated with CD11b in NIF+/+ PMNs. To validate the effectiveness of CD11b blockade, we compared PMN function in NIF+/+ and Mac-1-deficient (Mac-1−/−) mice. Adhesion of both Mac-1−/− and NIF+/+ PMNs to endothelial cells in response to LPS was reduced in both types of PMNs and fully blocked only by the addition of anti-CD11a monoclonal antibody. This finding is indicative of intact CD11a function in the NIF+/+ PMNs but the blockade of CD11b function. CD11b inactivation in NIF+/+ mice interfered with lung PMN infiltration induced by E. coli and prevented the increase in lung microvessel permeability and edema formation, with most of the protection seen in the 1-h period after the E. coli. Thus our results demonstrate that CD11b plays a crucial role in mediating lung PMN sequestration and vascular injury in the early phase of gram-negative septicemia. The NIF+/+ mouse model, in which CD11b is inactivated by binding to NIF, is a potentially useful model for in vivo assessment of the role of PMN CD11b in the mechanism of vascular inflammation.

scholarly journals Mediation systems in bacterial lipopolysaccharide-induced hypotension and disseminated intravascular coagulation. I. The role of complement.

1975 ◽  
Vol 142 (6) ◽  
pp. 1570-1590 ◽  
Author(s):  
R J Ulevitch ◽  
C G Cochrane ◽  
P M Henson ◽  
D C Morrison ◽  
W F Doe
Keyword(s):  
Blood Pressure ◽  
Disseminated Intravascular Coagulation ◽  
Mononuclear Cells ◽  
Contrast Injection ◽  
Marked Contrast ◽  
Induced Hypotension ◽  
E Coli ◽  
Intravascular Coagulation ◽  
Arterial Blood

We have studied the role of complement in lipopolysaccharide (LPS)-induced hypotension and disseminated intravascular coagulation (DIC) by comparing the effects of injection of three preparations of LPS from E. Coli 0111:B4, S. minnesota Re595, and S. marcescens. Injections of nonlethal doses of these LPS preparations into normal rabbits produced decreases in mean arterial blood pressure during a 5-h period. When rabbits treated with cobra venom factor (CoF) to deplete C3 were injected with the various LPS preparations, mean arterial pressures fell at a rate and extent essentially identical to that observed in normal rabbits. Rabbits genetically deficient in C6 also demonstrated LPS-induced hypotensive changes. Only minimal, or no changes in plasma C3 levels or serum CH50 values were detected in normal rabbits after LPS injection. Hypotensive changes were also induced in rabbits when complement was rapidly activated by intravenous injection of CoF. In contrast to the hypotension induced by LPS, the fall in arterial pressure associated with the consumption of complement was short lived and required the rapid consumption of considerable amounts of C3. The occurrence of DIC noted in normal rabbits injected with each preparation of LPS was not inhibited in either rabbits treated with cobra factor or in C6-deficient rabbits. The DIC was most pronounced after injection of Re595 and S. marcescens LPS. Injection of the various LPS preparations produced a rapid disappearance of circulating neutrophils and mononuclear cells, which occurred with the same kinetics and to the same extent in normal, CoF-treated, and C6-deficient rabbits. Injection of either Re595 LPS or S. marcescens LPS produced a biphasic disappearance of circulating 51Cr-platelets. In contrast, injection of 0111:B4 LPS affected only slightly the rate of disappearance of 51Cr-platelets. Depletion of C3 by cobra factor treatment had no effect on the disappearance of platelets in animals injected with 0111:B4. In marked contrast cobra factor treatment greatly reduced the initial rapid disappearance of platelets in rabbits injected with either Re595 or S. marcescens LPS, but had no effect in the secondary disappearance phase.

scholarly journals Human plasma extrinsic pathway inhibitor activity: II. Plasma levels in disseminated intravascular coagulation and hepatocellular disease

Blood ◽  
1989 ◽  
Vol 74 (3) ◽  
pp. 994-998 ◽  
Author(s):  
TA Warr ◽  
LV Rao ◽  
SI Rapaport
Keyword(s):  
Liver Disease ◽  
Tissue Factor ◽  
Disseminated Intravascular Coagulation ◽  
Factor Viia ◽  
Test Sample ◽  
Factor Ix ◽  
Factor X ◽  
Extrinsic Pathway ◽  
Intravascular Coagulation ◽  
Hepatocellular Disease

Abstract Plasma or serum extrinsic pathway inhibitor (EPI) activity was measured in 24 patients with disseminated intravascular coagulation (DIC) and in 23 patients with severe hepatocellular disease. EPI was measured as activity in a test sample that inhibited factor VIIa/tissue factor (TF)- catalyzed activation of 3H-factor IX (activation peptide release) in the presence of factor X. Of the 24 patients with DIC, 13 had sepsis and five had metastatic carcinoma, disorders in which tissue factor is believed to initiate DIC. EPI activity ranged from 68% to 300% (mean 134% +/- 50%). Serial measurements in nine patients failed to show depletion of EPI activity coincident with worsening DIC. DIC induced by tissue factor or other activating materials may progress despite normal EPI levels. In the patients with liver disease, of whom 15 had decompensated chronic hepatocellular disease (two fatal cases) and eight had acute fulminant liver failure (seven fatal cases), plasma or serum EPI activity varied from less than 20% to 194%. Values were distributed in a bimodal fashion. EPI activity could not be correlated with either the etiology of the liver disease or the degree of prolongation of the prothrombin time. Patients with chronic hepatocellular disease who survived had normal or elevated EPI activity. Patients with fatal hepatic dysfunction had low, normal, or high values for EPI activity. This must mean that secretion of EPI from cells other than hepatocytes can maintain normal plasma EPI levels.

scholarly journals Disseminated intravascular coagulation in rabbits induced by administration of endotoxin or tissue factor: effect of anti-tissue factor antibodies and measurement of plasma extrinsic pathway inhibitor activity

Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1481-1489 ◽  
Author(s):  
TA Warr ◽  
LV Rao ◽  
SI Rapaport
Keyword(s):  
Tissue Factor ◽  
Disseminated Intravascular Coagulation ◽  
Factor Viia ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Extrinsic Pathway ◽  
Intravascular Coagulation ◽  
Activated Factor Vii ◽  
Factor Effect

Abstract Rabbits were given polyclonal anti-tissue factor (TF) immunoglobulin G (IgG) before an injection of endotoxin to test the hypothesis that TF triggers disseminated intravascular coagulation (DIC) after endotoxin. The rabbits had been prepared with cortisone to develop DIC after one injection of endotoxin. Anti-TF IgG substantially reduced the falls in fibrinogen, factors V and VIII, and platelets noted in control rabbits given preimmune IgG before endotoxin. At autopsy 24 hours later, fibrin was present in glomerular capillaries of 4 of 5 control rabbits, but in none of 11 rabbits given anti-TF IgG. DIC was also induced in a second group of rabbits by the infusion, over 4 hours, of 1 microgram/kg of purified, reconstituted rabbit brain TF. This resulted in striking falls in plasma fibrinogen, factors V, and VIII that were diminished, but not prevented by prior treatment with anti-TF IgG. Circulating activated factor VII, induced by either TF infusion or endotoxin, could not be detected after DIC. Mean plasma extrinsic pathway inhibitor (EPI) activity did not fall significantly after endotoxin, and only to about 65% of the preinfusion after infusion of TF. Thus, DIC induced by both agents proceeded despite nearly normal plasma EPI levels. Because EPI neutralizes factor VIIa/TF in vitro only after a short lag period, the DIC that persisted for up to 6 hours after injection of endotoxin suggests that TF activity continued to be generated during this period on cells to which the circulating blood was exposed. All animals given endotoxin became ill with cyanosis, tachypnea, cold ears, and diarrhea, regardless of whether they had received anti-TF IgG to attenuate DIC. Infusion of TF caused some animals to die acutely with pulmonary arterial thromboses, but surviving animals did not appear ill. The findings support the hypothesis that exposure of blood to TF triggers DIC after endotoxin, but is not important for the pathogenesis of endotoxin-induced shock.

THE ROLE OF PROTON ATPase SPECIFIC INHIBITOR $N,N'$-DICYCLOHEXYLCARBODIIMIDE AND EXTERNAL FORMATE CONCENTRATION ON $E.~COLI$ GROWTH DURING MIXED CARBON SOURCES FERMENTATION AT DIFFERENT pHs.

2021 ◽  
Vol 55 (1 (254)) ◽  
pp. 67-74
Author(s):  
Heghine Kh. Gevorgyan ◽  
Anait V. Vassilian ◽  
Karen A. Trchounian
Keyword(s):  
Regulatory Protein ◽  
Carbon Sources ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
E Coli ◽  
Proton Atpase ◽  
Mutant Strains ◽  
Atpase Inhibition ◽  
Compensatory Effect

This research is focused on the investigation of specific growth rate changes of $E.~coli$ wild type and mutant strains with defect of Hyd, FDH enzymes and FhlA regulatory protein in the presence of $N,N'$-dicyclohexylcarbodiimide (DCCD) and external formate various concentration during co-fermentation of glucose, glycerol and formate at pHs $5.5-7.5.$ The highest value of SGR was observed at pH 7.5. It was revealed that SGR depends on external formate concentration at all pHs. DCCD inhibitory effect was shown mainly at pH 7.5 and partially at pH 6.5 and 5.5. In the case of the F0F1-ATPase inhibition FhlA compensatory effect on SGR was revealed.

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