Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vitamin D metabolites influence the expression of various genes involved in calcium homeostasis, cell differentiation, and regulation of the immune system. Expression of these genes is mediated by the activation of the nuclear vitamin D receptor (VDR). Previous studies have shown that a hormonally active form of vitamin D, 1alpha,25-dihydroxyvitamin D3, exerts anticoagulant effects in cultured monocytic cells. To clarify whether activation of VDR plays any antithrombotic actions in vivo, hemostatic/thrombogenic systems were examined in normocalcemic VDR knock-out (KO) mice on a high calcium diet and compared with wild type and hypocalcemic VDRKO mice that were fed a regular diet. Platelet aggregation was enhanced significantly in normocalcemic VDRKO mice compared with wild type and hypocalcemic VDRKO mice. Aortic endothelial nitric-oxide (NO) synthase expression and urinary NOx excretions were reduced in hypocalcemic VDRKO mice, but not in normocalcemic VDRKO mice. Northern blot and RT-PCR analyses revealed that the gene expression of antithrombin in the liver as well as that of thrombomodulin in the aorta, liver and kidney was down-regulated in hypo- and normocalcemic VDRKO mice. Whereas tissue factor mRNA expression in the liver and kidney was up-regulated in VDRKO mice regardless of plasma calcium level. Furthermore, VDRKO mice manifested an exacerbated multi-organ thrombus formation after exogenous lipopolysaccharide injection regardless of the calcemic conditions. These results demonstrate that activation of nuclear VDR elicits antithrombotic effects in vivo, and suggest that the VDR system may play a physiological role in the maintenance of antithrombotic homeostasis.
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PMID:Disruption of nuclear vitamin D receptor gene causes enhanced thrombogenicity in mice. 1520 60

Gram-negative sepsis is associated with disseminated intravascular coagulation (DIC) due to endothelial damage, which is induced by inflammatory mediators released from phagocytes activated by lipopolysaccharide (LPS). DIC is a systemic hemorrhagic syndrome, which results from the consumption of coagulation factors for the formation of multiple thrombi in the systemic microvessels; it is associated with multiple organ failure. Therefore, not only the systemic activation of coagulation but also the inflammatory response has been perceived as the therapeutic target for DIC in sepsis. We gave attention that protein C inhibitor (PCI) acts as an inhibitor of both plasma kallikrein and thrombin, which are known to act not only as procoagulant proteases but also as chemotactic factors toward phagocytes. Then, we hypothesized that PCI possibly acts as an anti-DIC agent rather than an inhibitor of the protein C anticoagulant pathway under the pathophysiology of DIC, accompanied by the decrease in the thrombomodulin expression on endothelial cells. Our studies have suggested that PCI purified from human urine (uPCI) improves the pathophysiology of DIC through the inhibition of activities of plasma kallikrein and thrombin, and the activities of PCI are regulated by N-glycans. This review introduces the anti-DIC action of PCI and about the modification of N-glycosylation site(s) of PCI to heighten the value of PCI as an anti-DIC agent.
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PMID:Protein C inhibitor as an anti-disseminated intravascular coagulation agent--mechanism and modification. 1532 Aug 3

In the present study, we evaluated the effect of epidural analgesia on the alterations of gut barrier function elicited by endotoxin in rabbits. After the placement of an epidural catheter, 28 male rabbits were randomized into either 0.5% lidocaine (group E) or saline (group C) group. The solutions (0.4 mL/kg) were epidurally injected, followed by continuous infusion (0.1 mL . kg(-1) . h(-1)) throughout the study period. Under a continuous infusion of lipopolysaccharide (15 microg . kg(-1) . h(-1)), mean arterial blood pressure, intramucosal pH, and plasma thrombomodulin concentrations were measured. At 4 h, mean arterial blood pressure was lower (P < 0.05), intramucosal pH was higher (P < 0.01), and the progression of hemodilution more profound (P < 0.05) in group E versus group C, whereas plasma thrombomodulin levels were increased to a similar extent between the groups. With less wet-to-dry weight ratio of ileum, histopathological injury scores of gut mucosa were significantly less in group E versus group C (P < 0.01). In a separate series of experiments (n = 10 each group), mucosal permeability in group E was significantly less compared with group C (P < 0.05). Collectively, these studies showed that despite a significant decrease of perfusion pressure and arterial oxygen content, epidural analgesia minimized endotoxin-induced functional and structural injury of gut mucosa possibly through endothelium-independent mechanisms.
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PMID:Epidural analgesia prevents endotoxin-induced gut mucosal injury in rabbits. 1597 43

Veno-occlusive disease of the liver (VOD) remains a troubling and potentially fatal complication of high-dose chemotherapy and hematopoietic stem cell transplantation conditioning regimens. No effective therapy has been available for these patients to date, and the best supportive care measures remain woefully inadequate. Defibrotide (DF) (Gentium, S.p.A., Como, Italy), a polydisperse mixture of all the single-stranded phosphodiester oligodeoxyribonucleotides that can be obtained from the controlled depolymerization of porcine intestinal mucosal genomic DNA, seems to offer a safe and effective treatment for some patients suffering from severe VOD, a condition for which no accepted standard therapy currently exists. Early clinical studies evaluating the efficacy of DF for the treatment of severe VOD in patients undergoing hematopoietic stem cell transplantation have been very encouraging. Approximately 45% of the patients treated in multiple initial phase II clinical trials achieved a complete response at day +100, demonstrating normalization of serum bilirubin and resolution of the clinical syndrome. However, although multi-institutional, these represented single arm studies. A large, FDA-approved, pivotal, prospective, multi-institutional, global phase III trial of DF vs. historical controls (best available therapy) commenced in the first quarter of 2006 and should provide further validation of DF's efficacy. The drug seems to have few significant side effects, and almost all test subjects who have received this treatment have tolerated it well. Although the mechanism of action remains unclear, the drug exerts minimal systemic anticoagulant effects yet appears to induce numerous antithrombotic and profibrinolytic effects both in vitro and in vivo. It may function as an adenosine receptor agonist and causes increased concentrations of endogenous prostaglandins, which modulate thrombomodulin, platelets, and fibrinolysis. It also appears to block lipopolysaccharide (LPS)-induced tissue factor (TF) expression. However, despite the fact the DF is composed of oligonucleotides, its mechanism of action, which at the present time is unclear, is not related to Watson-Crick base pair-dependent downregulation of gene expression but is rather likely a result of its polyanionic nature.
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PMID:Defibrotide, a polydisperse mixture of single-stranded phosphodiester oligonucleotides with lifesaving activity in severe hepatic veno-occlusive disease: clinical outcomes and potential mechanisms of action. 1658 99

Although it has been well documented that vitamin D receptor (VDR) activation influences the expression of various genes involved in calcium homeostasis and cell differentiation, the physiological role of VDR action in hemostasis remains unclear. We studied thrombogenicity in normocalcemic VDR knock-out (KO) mice on a high calcium diet in comparison with that in wild-type mice and that in hypocalcemic VDRKO mice fed a regular diet. Platelet aggregation was significantly enhanced in normocalcemic VDRKO mice. Aortic endothelial nitric-oxide (NO) synthase expression and urinary NOx excretion were reduced in hypocalcemic VDRKO mice but not in normocalcemic VDRKO mice. The gene expression of antithrombin in the liver and that of thrombomodulin in the aorta, liver and kidney were down-regulated in hypo- and normocalcemic VDRKO mice, whereas tissue factor gene expression in the liver and kidney was up-regulated in VDRKO mice regardless of plasma calcium level. Furthermore, VDRKO mice manifested an exacerbated multi-organ thrombus formation after exogenous lipopolysaccharide injection regardless of the calcemic conditions. These results demonstrate that the vitamin D-VDR system plays a pivotal role in antithrombogenicity in vivo.
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PMID:[Vitamin D-vitamin D receptor system regulates antithrombogenicity in vivo]. 1681 78

Thrombomodulin has a central role in the regulation of coagulation through its abilities to promote generation of the potent anticoagulant activated protein C. Because little is known about monocyte thrombomodulin expression and its regulatory mechanism by lipopolysaccharide, we investigated the effect of lipopolysaccharide on monocyte's thrombomodulin expression. Lipopolysaccharide reduced the surface thrombomodulin expression of human peripheral blood monocytes in a dose-dependent and time-dependent manner, regardless of the addition of serum. The surface thrombomodulin activity was comparably decreased in monocytes incubated with lipopolysaccharide. Blocking nuclear factor-kappaB by MG132 or aurine tricarboxylic acid effectively inhibited the lipopolysaccharide-induced surface thrombomodulin down-regulation of monocytes. Lipopolysaccharide inactivation by polymyxin B in the supernatants from the lipopolysaccharide-stimulated cultures still reduced the surface thrombomodulin expression of monocytes, suggesting a role for soluble mediators in the down-regulation of thrombomodulin. The lipopolysaccharide-induced thrombomodulin surface expression and the mRNA levels of the monocytic leukemic cell line (THP-1) were decreased in serum-depleted culture, while they were increased in medium containing 10% serum. We conclude that lipopolysaccharide down-regulates the thrombomodulin expression of monocytes and that nuclear factor-kappaB is a critical mediator of the repression of thrombomodulin by lipopolysaccharide. Regulation of the THP-1 thrombomodulin expression by lipopolysaccharide depends on the presence of serum.
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PMID:Lipopolysaccharide down-regulates the thrombomodulin expression of peripheral blood monocytes: effect of serum on thrombomodulin expression in the THP-1 monocytic cell line. 1728 33

An essential coagulation factor, tissue factor (TF), is rapidly expressed by human monocytes when exposed to a variety of agonists, such as lipopolysaccharide or tumor necrosis factor (TNF). We previously found that 1alpha,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) and its potent synthetic analogs downregulate TF and upregulate thrombomodulin expression on monocytic cells, counteracting the effects of TNF at the level of transcription. The human TF gene has characteristic binding sequences for activator protein-1 (AP-1) (c-Jun/c-Fos), nuclear factor-kappaB (NF-kappaB), Sp-1, and early growth response factor-1 (Egr-1). In this study, we investigated the regulatory mechanisms by which 1,25(OH)(2)D(3) inhibits TNF-induced TF expression in human monocytic cells. 1,25(OH)(2)D(3) reduced basal and TNF-induced TF activities. Gel-shift assay and luciferase assay with the respective reporter vectors showed that 1,25(OH)(2)D(3) reduced basal and TNF-induced activities of the nuclear proteins AP-1 and NF-kappaB, but not Egr-1. 1,25(OH)(2)D(3) inhibited TNF-induced phosphorylation of c-Jun without affecting phosphorylation of the other pathways. On the other hand, 1,25(OH)(2)D(3) directly inhibited nuclear binding and activities of NF-kappaB in the nucleus without affecting phosphorylation of the NF-kappaB activation pathway. These results indicate that 1,25(OH)(2)D(3) suppresses basal and TNF-induced TF expression in monocytic cells by inhibition of AP-1 and NF-kappaB activation pathways, but not of Egr-1. Our results may help to elucidate the regulatory mechanisms of 1,25(OH)(2)D(3) in TF induction, and may have physiological significance in the clinical challenge to use potential 1,25(OH)(2)D(3) analogs in antithrombotic therapy as well as immunomodulation and antineoplastic therapy of leukemia.
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PMID:1,25(OH)(2)D(3) blocks TNF-induced monocytic tissue factor expression by inhibition of transcription factors AP-1 and NF-kappaB. 1740 35

Thrombomodulin has a central role in the regulation of coagulation through its ability to promote generation of the potent anticoagulant, activated protein C. Aurintricarboxylic acid (ATA) has been reported to inhibit platelet function by blocking von Willebrand factor binding to platelet glycoprotein Ib and to impede thrombosis development in vivo. In the present study, we demonstrated a novel antithrombotic effect of ATA. The surface thrombomodulin expression of endothelial cells and peripheral blood monocytes was upregulated by ATA in a dose-dependent and time-dependent manner. ATA also increased the mRNA level of endothelial thrombomodulin in a dose-dependent manner. Tumor necrosis factor (TNF)-alpha (50 ng/ml) or lipopolysaccharide (20 microg/ml) downregulated the expression of endothelial thrombomodulin. Blocking of nuclear factor-kappaB by parthenolide effectively inhibited the TNF-alpha-induced thrombomodulin downregulation of endothelial cells. ATA increased endothelial thrombomodulin expression that was downregulated by TNF-alpha or lipopolysaccharide, in a dose-dependent manner. The inhibition of small G proteins of the Rho family by the Clostridium difficile toxin B-1,0643 did not increase thrombomodulin expression of endothelial cells, and ATA did not activate Rac1 in endothelial cells. These findings provide, at least in part, a novel platelet-independent mechanism of ATA that may explain the demonstrated antithrombotic efficacy of ATA.
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PMID:Aurintricarboxylic acid upregulates the thrombomodulin expression of endothelial cells and peripheral blood monocytes. 1868 31

Increasing evidence demonstrates that interleukin (IL)-32 is a pro-inflammatory cytokine, inducing IL-1alpha, IL-1beta, IL-6, tumor necrosis factor (TNF)-alpha, and chemokines via nuclear factor (NF)-kappaB, p38 mitogen-activated protein kinase (MAPK), and activating protein (AP)-1 activation. Here we report that IL-32 is expressed and is also functional in human vascular endothelial cells (EC) of various origins. Compared with primary blood monocytes, high levels of IL-32 are constitutively produced in human umbilical vein EC (HUVEC), aortic macrovascular EC, and cardiac as well as pulmonary microvascular EC. At concentrations as low as 0.1 ng/ml, IL-1beta stimulated IL-32 up to 15-fold over constitutive levels, whereas 10 ng/ml of TNFalpha or 100 ng/ml of lipopolysaccharide (LPS) were required to induce similar quantities of IL-32. IL-1beta-induced IL-32 was reduced by inhibition of the IkappaB kinase-beta/NF-kappaB and ERK pathways. In addition to IL-1beta, pro-coagulant concentrations of thrombin or fresh platelets increased IL-32 protein up to 6-fold. IL-1beta and thrombin induced an isoform-switch in steady-state mRNA levels from IL-32alpha/gamma to beta/epsilon. Adult EC responded in a similar fashion. To prove functionality, we silenced endogenous IL-32 with siRNA, decreasing intracellular IL-32 protein levels by 86%. The knockdown of IL-32 resulted in reduction of constitutive as well as IL-1beta-induced intercellular adhesion molecule-1 (ICAM-1) (of 55% and 54%, respectively), IL-1alpha (of 62% and 43%), IL-6 (of 53% and 43%), and IL-8 (of 46% and 42%). In contrast, the anti-inflammatory/anti-coagulant CD141/thrombomodulin increased markedly when IL-32 was silenced. This study introduces IL-32 as a critical regulator of endothelial function, expanding the properties of this cytokine relevant to coagulation, endothelial inflammation, and atherosclerosis.
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PMID:IL-32-dependent effects of IL-1beta on endothelial cell functions. 1922 41

Glucocorticoid usage especially at high doses is complicated by adverse outcomes such as thrombotic events or acceleration of inflammatory response in conditions like myeloma and osteonecrosis. The mechanism(s) through which high-dose dexamethasone (HDDEXA) causes vascular injury remains unclear. We hypothesized that HDDEXA sensitizes endothelial cells (EC) to the effect of inflammatory mediators and modulates endothelial haemostatic gene expression and leukocyte adhesion. Human umbilical vein endothelial cells (HUVECs) were grown in the absence or presence of HDDEXA and were also tested in the presence or absence of tumor necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS) or thrombin. mRNA and protein expression were measured and the functional consequences of HDDEXA preconditioning on cell adhesion molecules (CAM) were determined by agonist-mediated leukocyte adhesion assay. Treatment with HDDEXA resulted in an increased induction of CAM, tissue factor and von Willebrand factor, while down-regulating thrombomodulin and urokinase. HDDEXA alone had no effect on adhesion but resulted in enhanced TNF-alpha- and LPS-mediated adhesion of neutrophils. Together, these findings suggest that HDDEXA sensitizes HUVEC to the effect of inflammatory mediators and induces a pro-adhesive environment in primary EC. This finding is of importance when glucocorticoid usage is required at therapeutic high doses in patients with or without thrombotic risk factors.
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PMID:Effect of high-dose dexamethasone on endothelial haemostatic gene expression and neutrophil adhesion. 1944 30


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