Inactivation of Human Antithrombin by Neutrophil Elastase

Jordan, Robert E.; Nelson, Richard M.; Kilpatrick, J; Newgren, James O.; Esmon, Pamela C.; Fournel, Michael A.

doi:10.1016/s0021-9258(18)81648-9

Cited by 64 publications

(13 citation statements)

References 57 publications

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“…The rate of ATIII cleavage by human neutrophil elastase was slightly increased in the presence of pentasaccharide and greatly increased in the presence of 25-kDa high-affinity heparin (Table IV), which agrees with the results of Jordan et al (1989). This corresponds to the effect of pentasaccharide and 25-kDa high-affinity heparin on thrombin inhibition by ATIII (Table II).…”

Section: Arg47supporting

confidence: 87%

Heparin binding site, conformational change, and activation of antithrombin

Evans¹,

Marshall²,

Christey³

et al. 1992

Biochemistry

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Alignment of the heparin-activated serpins indicates the presence of two binding sites for heparin: a small high-affinity site on the D-helix corresponding in size to the minimal pentasaccharide heparin, and a longer contiguous low-affinity site extending to the reactive center pole of the molecule. Studies of the complexing of antithrombin and its variants with heparin fractions and with reactive center loop peptides including intermolecular loop-sheet polymers all support a 3-fold mechanism for the heparin activation of antithrombin. Binding to the pentasaccharide site induces a conformational change as measured by circular dichroism. Accompanying this, the reactive center becomes more accessible to proteolytic cleavage and there is a 100-fold increase in the kass for factor Xa but only a 10-fold increase for thrombin, to 6.4 x 10(4) M-1 s-1. To obtain a 100-fold increase in the kass for thrombin requires in addition a 4:1 molar ratio of disaccharide to neutralize the charge on the extended low-affinity site. Full activation requires longer heparin chains in order to stabilize the ternary complex between antithrombin and thrombin. Thus, addition of low-affinity but high molecular weight heparin in conjunction with pentasaccharide gives an overall kass of 2.7 x 10(6) M-1 s-1, close to that of maximal heparin activation.

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Section: Arg47supporting

confidence: 87%

Heparin binding site, conformational change, and activation of antithrombin

Evans¹,

Marshall²,

Christey³

et al. 1992

Biochemistry

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“…These receptors, present mainly on hepatocytes, are probably responsible for bulk removal of proteinase activity during episodes of inflammation, coagulation, and fibrinolysis. In the present study, we show that proteolytically modified serpins are not recognized by SRI or SR2, extending a recent report that modified ATIII is cleared very slowly from the circulation of rabbits (Jordan et al, 1989).…”

Section: Discussionsupporting

confidence: 89%

“…In doing so, it is exposed to attack by proteinases such as those from bacteria and snake venoms for which this region is a good substrate (Salvesen . Significantly, the loop of some serpins is also sensitive to certain host proteinases, the most intensively studied being human neutrophil elastase (HNE) (Brower & Harpel, 1982; Jordan et al, 1989). We can,…”

mentioning

confidence: 99%

Analysis of the plasma elimination kinetics and conformational stabilities of native, proteinase-complexed and reactive site cleaved serpins: comparison of .alpha.1-proteinase inhibitor, .alpha.1-antichymotrypsin, antithrombin III, .alpha.2-antiplasmin, angiotensinogen, and ovalbumin

Mast

Enghild²,

Pizzo³

et al. 1991

Biochemistry

225

162

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Proteinase inhibitors of the serpin superfamily may exist in one of three distinct conformations: the native form, a fully active protein with the reactive site loop intact; the proteolytically modified form in which inhibitory capacity is abolished; and the proteinase-complexed form, a stable equimolar complex between the inhibitor and a target proteinase. Here, the specificity and kinetics of the plasma elimination of different serpin conformations are compared. Proteinase-complexed serpins were rapidly cleared from the circulation. However, the native and modified forms were not cleared rapidly, indicating that the receptor-mediated pathways which recognize the complexes fail to recognize the native and modified forms. This result suggests that significant structural differences exist between modified and proteinase-complexed serpins. The structural differences were probed by using transverse urea gradient gel electrophoresis, a technique that allows comparisons of the conformational stabilities of proteins. With the exception of the noninhibitory serpins ovalbumin and angiotensinogen, the modified and proteinase-complexed serpins were both stabilized thermodynamically compared to the native forms. In addition, the proteinase component of the serpin-proteinase complex was usually thermodynamically stabilized. These data are used to compare the conformations of serpin-proteinase complexes with those of native and modified serpins; they are discussed in terms of a model whereby serpins inhibit proteinases in a manner similar to that described for other types of protein inhibitors of serine proteinases.

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“…However, upon NET release, these granular enzymes are released into the extracellular space. Interestingly, elastase, a serine protease found among the granular enzymes, inactivates or degrades AT [27,28]. Elastase-degraded AT may exhibit reduced inhibition of thrombin-induced activities in cauterized mice.…”

Section: Discussionmentioning

confidence: 99%

“…This may suggest that inhibition of either process might result in partial protection against adhesion formation. Moreover, AT administered could not fully exert its anticoagulant activity under conditions of NET release, because elastase liberated by the NET release, might inactivate and degrade AT [27,28]. These prompted us to propose the hypothesis that adhesions may only be eliminated completely when both pathways are ablated.…”

Section: Introductionmentioning

confidence: 99%

Antithrombin Together with NETs Inhibitor Protected Against Postoperative Adhesion Formation in Mice

Sudo

Mitani

et al. 2021

Cell Physiol Biochem

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BACKGROUND/AIMS: Postoperative adhesions may induce adverse outcomes in patients. Adhesion formation is initiated by fibrin accumulation at the surgical site which is followed by local neutrophilia and the establishment of neutrophil extracellular traps (NET). Previous reports have suggested that the preventive efficacy of reagents designed to reduce postoperative adhesion is inversely correlated with neutrophilia and NET production. Antithrombin (AT) is a natural inhibitor of thrombin, a key factor in coagulation. Here, we evaluate whether treatment with AT and/or NET inhibitors prevent or reduce postoperative adhesion formation in mice. METHODS: Mice were treated with AT and/or NET inhibitors before and/or after cecum cauterization and their adhesion scores were evaluated on day 7 post-operation. Immunochemistry/ immunofluorescence analyses were also performed and we used GSK484, an inhibitor of peptidyl arginine deiminase 4 (PAD4), as the NET inhibitor. RESULTS: AT or GSK484 partially rescued postoperative adhesion formation in mice. AT prevented thrombin-induced plasminogen activator inhibitor 1 and interleukin-6 expression in mesothelial cells in vitro. However, AT could not prevent neutrophilia or NETs formation around the injured serosa. Finally, we investigated a combination of AT and a PAD4 inhibitor and found that this could inhibit almost all adhesion formation in these animals. Since AT-inactivating proteases are liberated following NET release, they might dampen the biological action of the AT treatment. This suggests that NET inhibitors might allow AT to exert its full action in the surgically injured serosa.

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Inactivation of Human Antithrombin by Neutrophil Elastase

Cited by 64 publications

References 57 publications

Heparin binding site, conformational change, and activation of antithrombin

Heparin binding site, conformational change, and activation of antithrombin

Analysis of the plasma elimination kinetics and conformational stabilities of native, proteinase-complexed and reactive site cleaved serpins: comparison of .alpha.1-proteinase inhibitor, .alpha.1-antichymotrypsin, antithrombin III, .alpha.2-antiplasmin, angiotensinogen, and ovalbumin

Antithrombin Together with NETs Inhibitor Protected Against Postoperative Adhesion Formation in Mice

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