Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Despite recent advances in antibiotic therapy and intensive care, sepsis remains the most common cause of death in the intensive care units, claiming approximately 225000 victims annually in the USA alone. The pathogenesis of sepsis is attributable, at least in part, to dysregulated systemic inflammatory responses characterized by excessive accumulation of various proinflammatory cytokines. A ubiquitous nuclear protein, high mobility group box 1 (HMGB1), is released by activated macrophages/monocytes, and functions as a late mediator of lethal endotoxaemia and sepsis. First, circulating HMGB1 levels are elevated in a delayed fashion (after 16-32h) in endotoxaemic and septic animals. Second, administration of recombinant HMGB1 to mice recapitulates many clinical signs of sepsis, including fever, derangement of intestinal barrier function, lung injury and lethal multiple organ failure. Third, administration of anti-HMGB1 antibodies or inhibitors (e.g. ethyl pyruvate, nicotine, stearoyl lysophosphatidylcholine and Chinese herbs such as Angelica sinensis) protects mice against lethal endotoxaemia, and rescues mice from lethal experimental sepsis even when the first doses are given 24 hours after onset of sepsis. Taken together, these experimental data establish HMGB1 as a late mediator of lethal endotoxaemia and sepsis with a wider therapeutic window for the clinical management of lethal systemic inflammatory diseases.
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PMID:HMGB1 as a potential therapeutic target. 1738 Jul 89

The nuclear factor-kappa B (NF-kappaB) family of transcription factors is known to play an important role in the regulation of the immune system. NF-kappaB is activated by bacterial and viral antigens, which lead to the production of proinflammatory cytokines and chemokines. The rapid detection of activated NF-kappaB by systemic inflammatory response syndrome (SIRS) is considered to be crucial for the treatment of patients with septicemia. The aim of the present study was to evaluate the sensitivity of two methods, electrophoretic mobility shift assay (EMSA) and transcription factor enzyme-linked immunoassay (TF-ELISA). TF-ELISA detected 25ng of recombinant human NF-kappaB p50 (rhp50) and 5 microg of TNFalpha-stimulated HeLa nuclear protein, while EMSA detected approximately 100 ng of rhp50 and 10 microg of HeLa nuclear protein. We found that TF-ELISA was more sensitive than EMSA in detecting NF-kappaB; however, it was judged that the 3-6 hour measuring time required in TF-ELISA was excessively long for patients with SIRS. Therefore, the development of new analytical methods with improved sensitivity and measurement time was necessary for the detection and quantification of activated NF-kappaB protein in the hospital laboratory. Consequently, we have developed a new NF-kappaB analyzer based on surface plasmon resonance (SPR), which is recognized as one of the most sensitive direct optical detection methods. This method can detect nanomolar concentrations of NF-kappaB within 15 minutes. In addition, we have developed new experimental apparatus for the detection of NF-kappaB based on fluorescence correlation spectroscopy (FCS), which is able to analyze binding between DNA and protein in the liquid phase. At present, we are carrying out clinical trials using this new transcription factor analysis apparatus for SIRS patients.
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PMID:[Development of molecular pathology analysis testing which can be practiced in the hospital laboratory. The clinical application of a transcription factor activation test]. 1744 71

High-mobility group protein 1 (HMGB1) is a nonhistone nuclear protein whose function depends on cellular location. Inside the cell, HMGB1 modulates a variety of important cellular processes, including transcription, whereas outside the cell, HMGB1 acts as a cytokine that can promote inflammation and mediate sepsis and arthritis in animal models. In in vitro studies, proinflammatory molecules such as LPS, lipoteichoic acid, polyinosinic-polycytidylic acid (poly(I:C)), TNF-alpha, and type I and II IFNs can induce HMGB1 release from macrophages. Although these agents can activate cells, they can also induce apoptosis under certain circumstances. Therefore, because of evidence that apoptotic as well as necrotic cells can contribute to HMGB1-mediated events in sepsis, we have investigated the relationship between apoptosis and HMGB1 release in macrophages and other cells. In these experiments, using RAW 264.7 cells as a model, LPS and poly(I:C) caused HMGB1 release into the medium whereas CpG ODN failed to induce this response. With both LPS and poly(I:C), the extent of HMGB1 release correlated with the occurrence of apoptosis as measured by caspase 3 activation, lactate dehydrogenase release, and TUNEL staining. Similar results were obtained with primary murine macrophages as well as human Jurkat T cells. For Jurkat cells, poly(I:C) and NO donors induced apoptosis as well as HMGB1 release. Together, these results indicate that HMGB1 release from macrophages is correlated with the occurrence of apoptosis and suggest that these processes reflect common mechanisms and can occur concomitantly.
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PMID:The relationship between apoptosis and high-mobility group protein 1 release from murine macrophages stimulated with lipopolysaccharide or polyinosinic-polycytidylic acid. 1747 79

High mobility group box 1 protein (HMGB1) is a highly conserved, ubiquitous non-histone nuclear protein, which participates in maintaining nucleosome structure, regulation of gene transcription, and modulating the activity of steroid hormone receptors. Substantial evidence demonstrated that HMGB1 could be secreted into the extracellular milieu, acts as a proinflammatory cytokine and mediates the downstream inflammatory responses in endotoxemia, arthritis and sepsis. Recently, several reports suggested that HMGB1 plays a key role in tumor angiogenesis through multiple mechanisms, including up-regulation of proangiogenic factors, promoting endothelial progenitor cells homing to ischemic tumor tissues and induction of endothelial cell migration and sprouting. And blockade of HMGB1 binding to the receptor for advanced glycation end products (RAGE) with anti-HMGB1 antibody, soluble RAGE or anti-RAGE neutralizing antibody has been proved to inhibit angiogenesis efficiently. Since HMGB1 A box peptide could antagonize the HMGB1 whole length protein by competitively binding to RAGE and has been considered as a HMGB1 specific antagonist, we postulate that the HMGB1 A box peptide could function as an anti-angiogenic agent to inhibit tumor angiogenesis. In our opinion, if the hypothesis proved to be practical, HMGB1 A box peptide could be widely used in clinical settings to treat malignant tumors.
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PMID:Inhibition of tumor angiogenesis by HMGB1 A box peptide. 1763 Feb 23

The nuclear protein high-mobility group box 1 (HMGB-1) promotes inflammation in sepsis, but little is known about its role in brain ischemia-induced inflammation. We report that HMGB-1 and its receptors, receptor for advanced glycation end products (RAGE), Toll-like receptor 2 (TLR2), and TLR4, were expressed in normal brain and in cultured neurons, endothelia, and glial cells. During middle cerebral artery occlusion (MCAO), in mice, HMGB-1 immunostaining rapidly disappeared from all cells within the striatal ischemic core from 1 h after onset of occlusion. High-mobility group box 1 translocation from nucleus to cytoplasm was observed within the cortical periinfarct regions 2 h after ischemic reperfusion (2 h MCAO). High-mobility group box 1 predominantly translocated to the cytoplasm or disappeared in cells that colabeled with the neuronal marker NeuN. Furthermore, RAGE was robustly expressed in the periinfarct region after MCAO. Cellular release of HMGB-1 was detected by immunoblotting of cerebrospinal fluid as early as 2 h after ischemic reperfusion (2 h MCAO). High-mobility group box 1 released from neurons, in vitro, after glutamate excitotoxicity, maintained biologic activity and induced glial expression of tumor necrosis factor alpha (TNFalpha). Anti-HMGB-1 antibody suppressed TNFalpha upregulation in astrocytes exposed to conditioned media from glutamate-treated neurons. Moreover, TNFalpha and the cytokine intercellular adhesion molecule-1 increased in cultured glia and endothelial cells, respectively, after adding recombinant HMGB-1. In conclusion, HMGB-1 is released early after ischemic injury from neurons and may contribute to the initial stages of the inflammatory response.
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PMID:Early release of HMGB-1 from neurons after the onset of brain ischemia. 1800 May 11

Originally described as a nuclear protein that bends DNA, the high mobility group box 1 protein (HMGB1) has recently emerged as a necessary and sufficient late mediator of severe sepsis. HMGB1 is therefore a molecular target that provides a wide window for clinical intervention in sepsis. Vasoactive intestinal peptide (VIP) and urocortin are two well known anti-inflammatory neuropeptides that protect against several immune disorders by regulating a wide panel of inflammatory mediators. In this study, we demonstrate the therapeutic effect of VIP and urocortin in various models of established sepsis: both agents reduced lethality induced by cecal ligation and puncture or by injection of live Escherichia coli. The therapeutic effect of VIP and urocortin was accompanied by a decrease in systemic levels of HMGB1. In addition, administration of recombinant HMGB1 completely reversed the protective effect of VIP and urocortin in experimental sepsis. In vitro and ex vivo studies show that both VIP and urocortin down-regulate translocation of HMGB1 from the nucleus to the cytoplasm and its subsequent secretion by activated macrophages, suggesting that macrophages are major targets in the inhibitory activity of these neuropeptides. To our knowledge, VIP and urocortin are the first endogenous inhibitors of HMGB1 secretion shown to improve sepsis survival in a clinically relevant time frame.
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PMID:Neuropeptides rescue mice from lethal sepsis by down-regulating secretion of the late-acting inflammatory mediator high mobility group box 1. 1840 88

While foreign pathogens and their products have long been known to activate the innate immune system, the recent recognition of a group of endogenous molecules that serve a similar function has provided a framework for understanding the overlap between the inflammatory responses activated by pathogens and injury. These endogenous molecules, termed alarmins, are normal cell constituents that can be released into the extracellular milieu during states of cellular stress or damage and subsequently activate the immune system. One nuclear protein, High mobility group box-1 (HMGB1), has received particular attention as fulfilling the functions of an alarmin by being involved in both infectious and non-infectious inflammatory conditions. Once released, HMGB1 signals through various receptors to activate immune cells involved in the immune process. Although initial studies demonstrated HMGB1 as a late mediator of sepsis, recent findings indicate HMGB1 to have an important role in models of non-infectious inflammation, such as autoimmunity, cancer, trauma, and ischemia reperfusion injury. Furthermore, in contrast to its pro-inflammatory functions, there is evidence that HMGB1 also has restorative effects leading to tissue repair and regeneration. The complex functions of HMGB1 as an archetypical alarmin are outlined here to review our current understanding of a molecule that holds the potential for treatment in many important human conditions.
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PMID:HMGB1: endogenous danger signaling. 1843 61

High-mobility group box 1 (HMGB1) is a nuclear protein that has been found to be a critical mediator of lethality in endotoxemia and sepsis. During the systemic inflammatory response, circulating levels of HMGB1 are increased, but in a delayed fashion compared with early inflammatory mediators. To counteract the inflammatory response of endotoxemia, a secondary anti-inflammatory response ensues in an attempt to prevent inflammation-induced tissue injury. One such cytoprotective gene that is induced during endotoxemia is heme oxygenase (HO)-1. HO-1, and its products of heme metabolism, possess anti-inflammatory and antioxidant properties to counter the damaging effects of endotoxemia. In the present study, we wanted to determine whether tissue and circulating levels of HMGB1 are increased further in the absence of HO-1 during endotoxemia, and whether this increase may contribute to the pathobiology of endotoxemia. Lung inflammation, HMGB1 protein levels, and expression of HMGB1 in inflammatory cells were increased in HO-1(-/-) mice compared with HO-1+/+ mice. After the administration of LPS, tissue levels of HMGB1 were not increased further in HO-1(-/-) mice; however, circulating levels of HMGB1 were higher when compared with HO-1+/+ mice. HO-1(-/-) mice treated with a carbon monoxide-releasing molecule or biliverdin showed a reduction in plasma HMGB1, which was associated with a marked improvement in survival. HO-1(-/-) mice given HMGB1-neutralizing antibody showed improvement in survival compared with control antibody. These data suggest that exaggerated circulating levels of HMGB1 contribute to endotoxin-induced mortality in the absence of HO-1.
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PMID:High-mobility group box 1 contributes to lethality of endotoxemia in heme oxygenase-1-deficient mice. 1909 91

Sepsis remains a major cause of morbidity and mortality worldwide. The systemic release of the nuclear protein HMGB1 is a late event in endotoxin-related lethality in mice. The platinating chemotherapeutic Cis induces DNA lesions that sequester HMGB1 within the nucleus of cells. We sought to determine if low, nontoxic doses of Cis could be an effective strategy in ameliorating sepsis-related mortality in a mouse model of CLP. In vitro studies with Cis prevented the LPS-induced release of HMGB1 from RAW264.7 cells, limited MAPK signaling, but had no effect on NF-kappaB activation or cytokine production. Low, nontoxic doses of Cis decreased mortality following CLP, whether delivered before or after puncture. Protection was associated with a decrease in the systemic release of HMGB1 and protection from end organ injury and in particular, less acute lung injury. Tissue-specific iNOS expression was markedly reduced. Low, nontoxic doses of Cis sequester HMGB1 effectively inside of the nucleus of LPS-stimulated immune cells and prevent its release in response to CLP. Platinating agents in general and Cis specifically may be a novel approach to the treatment of sepsis.
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PMID:Low-dose cisplatin administration in murine cecal ligation and puncture prevents the systemic release of HMGB1 and attenuates lethality. 1948 5

High-mobility group box 1 protein (HMGB1), an abundant nuclear protein, was recently established as a proinflammatory mediator of experimental sepsis. Although extracellular HMGB1 has been found in atherosclerotic plaques, its potential role in the pathogenesis of atherothrombosis remains elusive. In the present study, we determined whether HMGB1 induces tissue factor (TF) expression in vascular endothelial cells (ECs) and macrophages. Our data showed that HMGB1 stimulated ECs to express TF (but not TF pathway inhibitor) mRNA and protein in a concentration- and time-dependent manner. Blockade of cell surface receptors (including TLR4, TLR2, and RAGE) with specific neutralising antibodies partially reduced HMGB1-induced TF expression. Moreover, HMGB1 increased expression of Egr-1 and nuclear translocation of NF-kappaB (c-Rel/p65) in ECs. Taken together, our data suggest that HMGB1 induces TF expression in vascular endothelial cells via cell surface receptors (TLR4, TLR2, and RAGE), and through activation of transcription factors (NF-kappaB and Egr-1).
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PMID:High-mobility group box 1 protein induces tissue factor expression in vascular endothelial cells via activation of NF-kappaB and Egr-1. 1965 87


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