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Query: UNIPROT:P43026 (
lipopolysaccharide
)
62,215
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A Limulus intracellular coagulation inhibitor, designated LICI, was isolated from hemocytes of the Japanese horseshoe crab (Tachypleus tridentatus), using three steps of chromatography, including dextran sulfate-Sepharose CL-6B, Sephacryl S-200, and Mono S. LICI is a single-chain glycoprotein with an apparent M(r) = 48,000 estimated by SDS-polyacrylamide gel electrophoresis. It blocks the amidolytic activities of Limulus
lipopolysaccharide
-sensitive serine protease, factor C, by forming a covalent 1:1 complex with the protease. The second-order rate constant for inhibition of factor C was 2.5 x 10(6) M-1 s-1 at 37 degrees C. LICI also inhibited human alpha-thrombin, rat salivary kallikrein, bovine plasmin, and trypsin but not Limulus clotting enzyme, Limulus factor B, bovine
factor Xa
, human factor XIa, human tissue plasminogen activator, human urokinase, chymotrypsin, elastase, and papain. Glycosaminoglycans such as heparin and heparan sulfate had no effect on the inhibitory activity. A cDNA coding for LICI was isolated from a hemocyte cDNA library. The open reading frame of the 1,257-base pair cDNA codes for the mature protein of 394 amino acids, of which 223 residues were confirmed by amino acid sequence analysis. LICI shows significant sequence identities to members of the serpin superfamily, such as human plasminogen activator inhibitor type 2 (40%) and human monocyte/neutrophil elastase inhibitor (39%). LICI contains a putative reactive site, -Arg-Ser-, at the corresponding position present in several inhibitors of the serpin superfamily. The subcellular localization, determined using an anti-LICI polyclonal antibody, indicated that LICI colocates with the Limulus serine protease zymogens in large granules in the hemocyte.
...
PMID:A Limulus intracellular coagulation inhibitor with characteristics of the serpin superfamily. Purification, characterization, and cDNA cloning. 827 48
We investigated the effect of activated protein C (APC) on
lipopolysaccharide
(
LPS
)-induced pulmonary vascular injury in rats to investigate the possible usefulness of APC as a treatment for adult respiratory distress syndrome. Intravenously administered
LPS
(5 mg/kg) significantly increased pulmonary vascular permeability. APC prevented the
LPS
-induced increase in pulmonary vascular permeability observed at 6 hours. Heparin plus antithrombin III (ATIII) and active site-blocked
factor Xa
(DEGR-Xa), a selective inhibitor of thrombin generation, inhibited
LPS
-induced coagulopathy but did not prevent
LPS
-induced pulmonary vascular injury.
LPS
-induced pulmonary vascular injury was significantly attenuated in rats with nitrogen mustard-induced leukocytopenia and in rats treated with ONO-5046, a potent granulocyte elastase inhibitor. Administration of
LPS
also increased pulmonary accumulation of leukocytes, as evaluated by measurement of myeloperoxidase activity in the lungs. APC significantly reduced
LPS
-induced increases in pulmonary accumulation of leukocytes at 1 hour. Neither ATIII plus heparin nor DEGR-Xa inhibited leukocyte accumulation. Active site-blocked APC (DIP-APC) prevented neither the
LPS
-induced pulmonary accumulation of leukocytes nor the
LPS
-induced increase in pulmonary vascular permeability. These results suggest that the mechanism of APC inhibition of
LPS
-induced pulmonary vascular injury was independent of its anticoagulant activity and was related to its ability to inhibit accumulation of leukocytes. In addition, these findings suggest that the serine protease activity of APC may be essential to its inhibitory effect on
LPS
-induced pulmonary accumulation of leukocytes and subsequent pulmonary vascular injury.
...
PMID:Activated protein C attenuates endotoxin-induced pulmonary vascular injury by inhibiting activated leukocytes in rats. 855 86
Adult respiratory distress syndrome (ARDS) is a serious complication of disseminated intravascular coagulation (DIC) or multiple organ failure. To determine whether recombinant soluble human thrombomodulin (rsTM) may be useful in treating ARDS due to sepsis, we investigated the effect of rsTM on
lipopolysaccharide
(
LPS
)-induced pulmonary vascular injury in rats. The intravenous administration of rsTM prevented the increase in pulmonary vascular permeability induced by
LPS
. Neither heparin plus antithrombin III (AT III) nor dansyl Glu Gly Arg chloromethyl ketone-treated
factor Xa
(DEGR-Xa), a selective inhibitor of thrombin generation, prevented
LPS
-induced vascular injury. The agents rsTM, heparin plus AT III, and DEGR-Xa all significantly inhibited the
LPS
-induced intravascular coagulation. Recombinant soluble TM pretreated with a monoclonal antibody (moAb) that inhibits protein C activation by rsTM did not prevent the
LPS
-induced vascular injury; in contrast, rsTM pretreated with a moAb that does not affect thrombin binding or protein C activation by rsTM prevented vascular injury. Administration of activated protein C (APC) also prevented vascular injury.
LPS
-induced pulmonary vascular injury was significantly reduced in rats with leukopenia induced by nitrogen mustard and by ONO-5046, a potent inhibitor of granulocyte elastase. Results suggest that rsTM prevents
LPS
-induced pulmonary vascular injury via protein C activation and that the APC-induced prevention of vascular injury is independent of its anticoagulant activity, but dependent on its ability to inhibit leukocyte activation.
...
PMID:Recombinant human soluble thrombomodulin reduces endotoxin-induced pulmonary vascular injury via protein C activation in rats. 860 7
We developed a sensitive tissue factor (TF) chromogenic assay on a limited number of endothelial cells (EC), performed in microtiter plates, and which uses a normal pooled human plasma instead of purified concentrates as a source of coagulation factors. Primary cultures of human umbilical vein EC (HUVEC), both unstimulated and stimulated by
lipopolysaccharide
(
LPS
) were incubated with 50 microliters of of diluted normal human plasma (NHP) and 50 microliters of Factor Xa-specific chromogenic substrate (CBS 31-39, Stago, France). Hirudin was added at 4 U/ml to the plasma/CBS 31-39 mixture to inhibit thrombin generation. Optical densities were read at 405 nm and corresponding amounts of generated
factor Xa
were expressed in mU Xa/well using a standard curve established with purified human Factor Xa. The following parameters were then defined: the number of EC to plate (10(4) EC/well of a 96-well plate), the plasma-test dilution (1:20), the concentration of CBS 31-39 (0.50 mM) and the incubation time of reagents with EC (2 hours). The procoagulant activity (PCA) measured was only dependent on TF since it was no longer detectable either when FVII-deficient plasma was tested instead of normal human plasma or when PCA assays were performed in the presence of a blocking anti-human TF monoclonal antibody. This method allowed detection of a TF-dependent PCA on as few as 1000 EC per well. In addition, TF expression equal to 50% of maximal values was measured with
LPS
concentrations as low as 1 ng/ml, supporting the high sensitivity of the assay.
...
PMID:A simplified and low-cost one-stage chromogenic assay for tissue factor dependent procoagulant activity of endothelial cells. 861 Feb 81
In vivo prothrombin activation is thought to occur via a
factor Xa
/factor V-dependent mechanism. We investigated whether human venous endothelial cells (EC) could be induced to express a prothrombin activator. EC treated with
lipopolysaccharide
(
LPS
) or interleukin-1 activated prothrombin in the absence of exogenous factors Xa and V. This activity resided in the membrane fraction of EC and was not inhibited by an antibody to factor V. The apparent Km value was 3.3 +/- 0.3 mumol/L. Comparative studies of thrombin generation using a model system of phospholipid and factors Xa/V versus
LPS
-treated EC were performed to quantitate the effects of known inhibitors to
factor Xa
. The
factor Xa
inhibitor DEGR-chloromethyl ketone and an antibody to factor X inhibited prothrombin activation. However, the EC activator did not hydrolyze a
factor Xa
chromogenic substrate, and recombinant tick anticoagulant peptide did not suppress activity of the prothrombin activator. The apparent molecular weight of the EC activator was approximately 30 kD. Exogenous factor V enhanced the activity of the EC activator, such that in the presence of factor V, the apparent K(m) value was 1.28 +/- 0.10 mumol/L. Additionally,
LPS
-treated EC activated exogenous factor V. This activator has several characteristics of a previously described inducible murine monocyte prothrombin activator and may contribute to thrombin generation associated with pathologic stimuli.
...
PMID:Characterization of an inducible endothelial cell prothrombin activator. 887 96
We investigated the effect of activated protein C (APC) on pulmonary vascular injury and the increase in tumor necrosis factor (TNF) levels in
lipopolysaccharide
(
LPS
)-treated rats to determine whether APC reduces
LPS
-induced endothelial damage by inhibiting cytokine production. Intravenously administered
LPS
(5 mg/kg) induced pulmonary vascular injury, as indicated by an increase in the lung wet-to-dry weight ratio.
LPS
-induced pulmonary vascular injury was prevented by APC but not by active site-blocked
factor Xa
[dansyl glutamyl-glycyl-arginyl chloromethyl detone-treated activated factor X (DEGR-Xa)], a selective inhibitor of thrombin generation, or inactivated APC [diisopropyl fluorophosphate-treated APC (DIP-APC)]. APC, but not DEGR-Xa or DIP-APC, significantly inhibited the
LPS
-induced increase in the plasma level of TNF. APC significantly inhibited the production of TNF by
LPS
-stimulated monocytes in a dose-dependent fashion in vitro, but DIP-APC did not. APC did not inhibit the functions of activated neutrophils in vitro. These findings suggest that APC prevented
LPS
-induced pulmonary vascular injury by inhibiting TNF production by monocytes and not via its anticoagulant activity. The serine protease activity of APC appears to be essential for inhibition of TNF production.
...
PMID:Activated protein C prevents LPS-induced pulmonary vascular injury by inhibiting cytokine production. 912 69
Sodding of vascular grafts involves coating the biomaterial with cells prepared from collagenase-digested fat tissue after removal of the adipocytes by centrifugation. The goal of this study was to investigate the staining characteristics of the sodding cells as well as their ability to express the procoagulant protein tissue factor, and to compare these findings to those found with extensively purified microvascular endothelial cells (MEC) prepared from similar tissue. Sodding cells and MEC, isolated using immunomagnetic separation with anti-PECAM antibodies, were prepared from liposuction material and endothelial-specific staining was compared. The expression of tissue factor on these cells was examined using both an ELISA and a chromogenic assay to assess the rate of generation of
factor Xa
. Sodding cells expressed significantly more tissue factor than the unstimulated MEC in which the expression was undetectable (sodding cells 2466 +/- 830 pg/mL, P < 0.05). There was no further increase in tissue factor expression in the sodding cells with stimulation with
lipopolysaccharide
(
LPS
); however, purified MEC expressed significantly more tissue factor after exposure to
LPS
(1247 +/- 356 pg/mL, P < 0.05). These results were confirmed by the determination of procoagulant activity of the cells whereby the procoagulant activity on unstimulated MEC was significantly less than that found after stimulation of these cells, and it was also less than stimulated and unstimulated sodding cells (absorbance at 405 nm: 0.423 +/- 0.125, unstimulated MEC; 1.000 +/- 0.438, stimulated MEC; 1.129 +/- 0.396, unstimulated sodding cells; 1.171 +/- 0.254, stimulated sodding cells, P < 0.05). Staining of these two cells types also demonstrated significant uptake of acetylated LDL (Ac-LDL) in the purified MEC which was essentially absent in the sodding cells. Further, vWf staining was found to a greater degree in the purified MEC than in the sodding cells. These experiments demonstrated that the cells prepared for cell sodding express large amounts of tissue factor. The sodding cells do not stain for antigens known to be specific for endothelial cells, whereas MEC do and therefore the concentration of endothelial cells in the sodding cells is small. The significance of the tissue factor expression on the surface of sodded grafts is not yet known.
...
PMID:Tissue factor expression by cells used for sodding of prosthetic vascular grafts. 934 10
Acute respiratory distress syndrome (ARDS) adversely affects the outcome of patients with disseminated intravascular coagulation (DIC) associated with sepsis. To determine whether antithrombin III (AT III) is useful for the treatment of ARDS in sepsis, we evaluated the effect of AT III on
lipopolysaccharide
(
LPS
)-induced pulmonary vascular injury in rats. Although the intravenous administration of AT III (250 U/kg) prevented
LPS
-induced pulmonary accumulation of leukocytes, increases in pulmonary vascular permeability, and coagulation abnormalities, inactivated
factor Xa
, a selective inhibitor of thrombin generation, did not prevent such events other than the coagulation abnormalities. AT III promotes the endothelial release of prostacyclin by interacting with cell surface glycosaminoglycans in vivo. Trp49-modified AT III, which lacks affinity for heparin, did not prevent
LPS
-induced pulmonary vascular injury. Plasma levels of 6-keto-prostaglandin F1alpha were markedly increased in rats after the administration of
LPS
and significantly decreased in the
LPS
-treated rats administered Trp49-modified AT III, but not altered in those
LPS
-treated rats receiving AT III. Preventive effects of AT III were not observed in rats pretreated with indomethacin, which inhibits prostacyclin biosynthesis. Prostacyclin prevents
LPS
-induced pulmonary vascular injury by inhibiting leukocyte accumulation in the lungs. These observations strongly suggest that AT III prevents pulmonary vascular injury induced by
LPS
by promoting the endothelial release of prostacyclin, a potent inhibitor of leukocyte activation.
...
PMID:Antithrombin III (AT III) prevents LPS-induced pulmonary vascular injury: novel biological activity of AT III. 946 34
We investigated annexin V expression and membrane vesiculation during activation of four leukemic cell lines (U937, HL60, HEL, and CMK11-5) in order to determine whether annexin V had a role in the coagulation abnormalities related to malignancy. After stimulation by tissue plasminogen activator, binding of a monoclonal anti-annexin V antibody to U937 cells and HL60 cells increased in comparison with binding to control cells. Stimulation with thrombin or
lipopolysaccharide
also induced such an increase, but U46619 did not. Following activation of U937 and HL60 cells with thrombin and
lipopolysaccharide
, microparticle formation increased. Tissue plasminogen activator caused an increase of microparticles in U937 cells, but not HL60 cells. On the other hand, CMK11-5 and HEL cells did not show any increase of microparticles. These results suggest that some agonists can potently stimulate expression of
prothrombinase
...
PMID:Annexin V expression and membrane vesiculation during activation of leukemic cell lines. 973 Nov 6
Recently, O'Reilly et al. (O'Reilly, M. S., Holmgren, L., Shing, Y., Chen, C., Rosenthal, R. A., Moses, M., Lane, W. S., Cao, Y., Sage, E. H., and Folkman, J. (1994) Cell 79, 315-328; O'Reilly, M. S., Boehm, T., Shing, Y., Fukai, N., Vasios, G., Lane, W. S., Flynn, E., Birkhead, J. R., Olsen, B. R., and Folkman, J. (1997) Cell 88, 277-285) developed a simple in vitro angiogenesis assay system using bovine capillary endothelial cell proliferation and purified potent angiogenic inhibitors, including angiostatin and endostatin. Using a simple in vitro assay for angiogenesis, we purified a protein molecule that showed anti-endothelial cell proliferative activity from the serum of New Zealand White rabbits, which was stimulated by
lipopolysaccharide
. The purified protein showed only bovine capillary endothelial cell growth inhibition and not any cytotoxicity. This molecule was identified as a prothrombin kringle-2 domain (fragment-2) using Edman degradation and the amino acid sequence deduced from the cloned cDNA. Both the prothrombin kringle-2 domain released from prothrombin by
factor Xa
cleavage and the angiogenic inhibitor purified from rabbit sera exhibited anti-endothelial cell proliferative activity. The recombinant rabbit prothrombin kringle-2 domain showed potent inhibitory activity with half-maximal concentrations (ED50) of 2 microg/ml media. As in angiostatin, the recombinant rabbit prothrombin kringle-2 domain also inhibited angiogenesis in the chorioallantoic membrane of chick embryos.
...
PMID:Prothrombin kringle-2 domain has a growth inhibitory activity against basic fibroblast growth factor-stimulated capillary endothelial cells. 978 80
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