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

Acute lung injury is frequently associated with sepsis or blood loss and is characterized by a proinflammatory response and infiltration of activated neutrophils into the lungs. Hemorrhage or endotoxemia result in activation of cAMP response element-binding protein (CREB) and NF-kappa B in lung neutrophils as well as increased expression of proinflammatory cytokines, such as TNF-alpha and macrophage-inflammatory peptide-2, by these cells. Activation of the extracellular regulated kinase (ERK) pathway occurs in stress responses and is involved in CREB activation. In the present experiments, hemorrhage or endotoxemia produced increased activation of mitogen-activated protein kinase kinase (MEK)1/2 and ERK2 (p42), but not of ERK1 (p44), in lung neutrophils. ERK1, ERK2, and MEK1/2 were not activated in peripheral blood neutrophils after hemorrhage or endotoxemia. Inhibition of xanthine oxidase led to further increase in the activation of MEK1/2 and ERK2 in lung neutrophils after hemorrhage, but not after endotoxemia. Alpha-adrenergic blockade before hemorrhage resulted in increased activation in lung neutrophils of MEK1/2, ERK1, ERK2, and CREB, but decreased activation of NF-kappa B. In contrast, alpha-adrenergic blockade before endotoxemia was associated with decreased activation of MEK1/2, ERK2, and CREB, but increased activation of NF-kappa B. Beta-adrenergic blockade before hemorrhage did not alter MEK1/2 or ERK1 activation in lung neutrophils, but decreased activation of ERK2 and CREB, while increasing activation of NF-kappa B. Beta-adrenergic inhibition before endotoxemia did not affect activation of MEK1/2, ERK1, ERK2, CREB, or NF-kappa B. These data indicate that the pathways leading to lung neutrophil activation after hemorrhage are different from those induced by endotoxemia.
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PMID:Activation of extracellular signal-regulated kinases, NF-kappa B, and cyclic adenosine 5'-monophosphate response element-binding protein in lung neutrophils occurs by differing mechanisms after hemorrhage or endotoxemia. 1112 32

Septic shock is the most common cause of death in intensive care units, and no effective treatment is available at present. Lipopolysaccharide (LPS) is the primary mediator of Gram-negative sepsis by inducing the production of macrophage-derived proinflammatory cytokines, in which activation of nuclear factor-kappaB (NF-kappaB) plays an important role. PC-SPES is an eight-herb mixture active against a variety of malignancies, including prostate cancer and leukemia. In this study, we demonstrated that PC-SPES inhibited the LPS-induced NF-kappaB reporter activity in RAW264.7 macrophages. Electrophoretic mobility shift assay showed that PC-SPES inhibited the binding of NF-kappaB to specific DNA sequences; however, it did not affect either degradation of inhibitory kappaBalpha or nuclear translocation of NF-kappaB. Also, we explored the effect of PCSPES on LPS-induced mitogen-activated protein (MAP) kinase signaling; PC-SPES did not affect LPS-induced phosphorylation of MAP kinases, including c-Jun NH2-terminal kinase, p38, and extracellular signal-regulated kinase 1/2. Moreover, PC-SPES decreased the production of proinflammatory cytokines and inducible enzymes, such as tumor necrosis factor (TNF) alpha, interleukin (IL)-1beta, IL-6, cyclooxygenase-2, as well as inducible nitric-oxide synthase in RAW264.7 macrophages and peritoneal macrophages from C57BL/6 mice after the cells were stimulated by either LPS or LPS and interferon-gamma. Furthermore, PC-SPES rescued C57BL/6 mice from death caused by LPS-induced septic shock in conjunction with decreased serum levels of TNFalpha and IL-1beta. Together, PC-SPES is a potent inhibitor of NF-kappaB and might be useful for the treatment of sepsis and inflammatory diseases.
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PMID:PC-SPES: a potent inhibitor of nuclear factor-kappa B rescues mice from lipopolysaccharide-induced septic shock. 1464 83

We hypothesized that sepsis during hyperglycemia would activate left ventricular (LV) mitogen activated protein kinase (MAPK) signaling mechanisms and modulate generation of endothelin-1 (ET-1) and nitric oxide (NO) that can contribute to the progression of LV dysfunction. A single injection of streptozotocin (STZ, 60 mg/kg, via tail vein) was used to produce type 2 diabetes in male SD rats. Polymicrobial sepsis and sham-sepsis were induced using single i.p. injection of cecal inoculum and sterile 5% dextrose water, respectively, on the 13th and 27th day following STZ injection. Both 2-week (2-wk) and 4-wk diabetes groups were associated with hyperglycemia and weight loss. LV end diastolic pressure (LVEDP) was significantly increased in 4-wk diabetes but not in 2-wk diabetes group. Plasma concentration of tumor necrosis factor-alpha (TNF-alpha) was significantly increased in 4-wk diabetes+sepsis group as compared to sham, 2-wk diabetes+sepsis and sepsis groups. Elevated plasma and LV ET-1 and NO byproducts (NOx) along with LV preproET-1 and inducible nitric oxide synthase (iNOS) protein expression were observed in 4-wk but not in 2-wk diabetes group. Sepsis further elevated LV iNOS and preproET-1 in 4-wk diabetes group. Up-regulated phosphorylation of LV p38-MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2) and heat shock protein-27 (Hsp27) was observed in 4-wk diabetes group. Sepsis caused a factorial increase in LV p38-MAPK and Hsp27 phosphorylation and iNOS up-regulation but not ERK1/2 following progression from 2-wk to 4-wk diabetes. The study provides evidence that sepsis up-regulated LV iNOS, p38-MAPK phosphorylation and elevated LVEDP during 4-wk diabetes. We concluded that sepsis contributes in the development of LVEDP dysfunction and alteration in signaling mechanisms depending upon the progression from 2-wk to 4-wk diabetes in the rat.
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PMID:Left ventricular mitogen activated protein kinase signaling following polymicrobial sepsis during streptozotocin-induced hyperglycemia. 1533 69

We tested the hypothesis that exogenous administration of the ET-1 precursor, bigET-1, would regulate adult rat ventricular myocyte (ARVM) contractility in a p38-mitogen activated protein kinase (p38-MAPK)-dependent mechanism during sepsis. Ventricular myocytes from adult rat hearts (both sham and septic) were stimulated to contract at 0.5 Hz and mechanical properties were evaluated using an IonOptix Myocam system. Immunoblot analysis was used to determine the phosphorylation of p38-MAPK and extracellular signal-regulated kinase 1/2 (ERK1/2). ARVMs were treated with vehicle, bigET-1 and inhibitors for 24 h and then subjected to functional and biochemical estimations. Septic ARVM displayed a distorted cell membrane and irregular network within the cells along with increased cell contractility as evidenced by elevated peak shortening (PS), maximal velocity of shortening (+dL/dt) and relengthening (-dL/dt) in comparison to sham ARVM. BigET-1 treatment caused ARVM enlargement in both sham and sepsis groups. BigET-1 (100 nM) produced an increase in ARVM contractility in sham group as compared to vehicle treatment. However, septic ARVM treated with bigET-1 exhibited unaltered ARVM contractility, and upregulated ET(B) receptors as compared to respective sham group. BigET-1 increased the concentration of ET-1 and upregulated phosphorylation of p38-MAPK but not of ERK1/2 in sham and septic ARVM. Furthermore, inhibition of p38-MAPK by SB203580 (10 microM) increased ARVM contractility in sham but not in sepsis group. BigET-1 reversed SB203580-induced increase in PS in sham group but accentuated it in sepsis group. BigET-1 also reversed SB203580-induced inhibition of p38-MAPK phosphorylation in sham but not in septic ARVM. SB203580 pretreatment followed by bigET-1 administration significantly decreased p38-MAPK phosphorylation and downregulated ET(B) receptor expression as compared to bigET-1 treatment per se in sepsis group but not in sham. We concluded that a bigET-1-induced non-responsive effect on septic ARVM contractile function could be due to upregulation of p38-MAPK phosphorylation and ET(B) receptor expression.
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PMID:Bigendothelin-1 via p38-MAPK-dependent mechanism regulates adult rat ventricular myocyte contractility in sepsis. 1595 56

Toll-like receptors (TLR) represent an ancient front-line defence system that enables the host organism to sense the presence of microbial components within minutes. As inducers of inflammation, TLR act as important triggers of distinct entities such as sepsis or autoimmune disease exacerbation. We report here that vitamin D3 [1alpha,25-dihydroxycholecalciferol, 1,25(OH)(2)D3] suppresses the expression of TLR2 and TLR4 protein and mRNA in human monocytes in a time- and dose-dependent fashion. Despite 1,25(OH)(2)D3-induced up-regulation of CD14, challenge of human monocytes with either LPS or lipoteichoic acid resulted in impaired TNF-alpha and procoagulatory tissue factor (CD142) production, emphasizing the critical role of TLR in the induction of inflammation. Moreover, reduced TLR levels in 1,25(OH)(2)D3-treated phagocytes were accompanied by impaired NF-kappaB/RelA translocation to the nucleus and by reduced p38 and p42/44 (extracellular signal-regulated kinase 1/2) phosphorylation upon TLR-ligand engagement. Both TLR down-regulation and CD14 up-regulation were substantially inhibited by the vitamin D receptor (VDR) antagonist ZK 159222, indicating that the immunomodulatory effect of 1,25(OH)(2)D3 on innate immunity receptors requires VDR transcription factor activation. Our data provide strong evidence that 1,25(OH)(2)D3 primes monocytes to respond less effectively to bacterial cell wall components in a VDR-dependent mechanism, most likely due to decreased levels of TLR2 and TLR4.
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PMID:Vitamin D3 down-regulates monocyte TLR expression and triggers hyporesponsiveness to pathogen-associated molecular patterns. 1640 4

Neutrophil accumulation in the lung plays a pivotal role in the pathogenesis of acute lung injury during sepsis. Directed movement of neutrophils is mediated by a group of chemoattractants, especially CXC chemokines. Local lung production of CXC chemokines is intensified during experimental sepsis induced by cecal ligation and puncture (CLP), as reflected by rising levels of MIP-2 and cytokine-induced neutrophil chemoattractant-1 in bronchoalveolar lavage fluids. Alveolar macrophages are primed and blood neutrophils are down-regulated for production of MIP-2 and cytokine-induced neutrophil chemoattractant production in response to LPS and C5a. Under these conditions of stimulation, activation of MAPKs (p38, p42/p44) occurs in sham neutrophils but not in CLP neutrophils, while under the same conditions phosphorylation of p38 and p42/p44 occurs in both sham and CLP alveolar macrophages. These data indicate that, under septic conditions, there is impaired signaling in neutrophils and enhanced signaling in alveolar macrophages, resulting in CXC chemokine production, and C5a appears to play a pivotal role in this process. As a result, CXC chemokines increase in lung, setting the stage for neutrophil accumulation in lung during sepsis.
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PMID:Divergent signaling pathways in phagocytic cells during sepsis. 1681 91

Neutrophilic polymorphonuclears (PMNs) play an important role in the progression of sepsis-related inflammation and become highly activated by a wide array of ligands on the site. The triggering receptor expressed on myeloid cells-1 (TREM-1) is a recently described receptor that has many effects on human PMN. The engagement of TREM-1 on PMN can induce phagocytosis, reactive oxygen species production and release of myeloperoxidase and IL-8. LPS has a priming effect on these functions. We show in this paper that Lyn, AKT, extracellular signal-regulated kinase 1/2 and Jak2 signaling pathways are elicited following TREM-1 engagement and activation by a monoclonal agonist antibody (anti-TREM-1) in human PMN, leading to the phosphorylation of STAT5 and RelA, a subunit of the nuclear factor-kappa B family. We also show that TREM-1 is recruited to ganglioside M1-lipid rafts in PMN upon stimulation with LPS or anti-TREM-1. Moreover, we observed that Toll-like receptor 4 and TREM-1 co-localize upon stimulation and TREM-1 engagement resulted in the phosphorylation of IL-1R-associated kinase 1, but not its stimulant-induced degradation. These data shed a new light on how various receptors implicated in the innate immune response could interact to insure an efficient inflammatory response upon pathogens-associated aggression.
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PMID:Effects of TREM-1 activation in human neutrophils: activation of signaling pathways, recruitment into lipid rafts and association with TLR4. 1709 18

Apurinic/apyrimidinic endonuclease 1/Redox factor-1 (APE1) is a multifunctional protein involved in reduction-oxidation regulation. High-mobility group box 1 (HMGB1) is released by necrotic cells and various inflammatory stimuli, acting as an inflammatory marker in sepsis and autoimmune diseases. Here, we report the dual regulatory role of APE1 in inflammatory signaling to extracellular HMGB1 or in the release of endogenous HMGB1 in human monocytes/macrophages. Forced cytoplasmic overexpression of APE1 profoundly attenuated the upregulation of HMGB1-mediated reactive oxygen species generation, cytokine secretion, and cyclooxygenase-2 expression by primary monocytes and macrophage-like THP-1 cell lines. In addition, HMGB1-induced activation of p38 and c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase 1/2, was strongly abrogated by the overexpression of APE1. The activation of apoptosis signal-regulating kinase 1 was required for both the p38 and JNK activation challenge with HMGB1. The extracellular release of HMGB1 by activated macrophages was inhibited by APE1 transfection. Small interfering RNA (siRNA) knockdown of endogenous APE1 impaired HMGB1-mediated cytokine expression and MAPK activation in THP-1 cells. HMGB1 stimulation induced the translocation of APE1 to the nucleus of the cell. In addition, APE1 silencing via siRNA transfection inhibited both the nuclear and cytoplasmic expression of APE1. These data identify APE1 as a novel dual regulator of inflammatory signaling to HMGB1 by human monocytes/macrophages. The modulation of cytosolic APE1 expression might be useful as a potential therapeutic modality for the treatment of inflammatory or autoimmune diseases.
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PMID:A dual regulatory role of apurinic/apyrimidinic endonuclease 1/redox factor-1 in HMGB1-induced inflammatory responses. 1871 45

Lack of specific and efficient therapy leads to the high mortality rate of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Losartan is a potent pharmaceutical drug for ALI/ARDS. However, the protective effects and mechanisms of losartan remain incompletely known. This study evaluates the effects of losartan on ALI/ARDS and further investigates the possible mechanisms of these protective effects. Mice received i.p. injections of the AT1 inhibitor losartan (15 mg/kg), or control vehicle, half hour after cecal ligation and puncture (CLP). Plasma TNF-alpha, IL-1beta, and IL-6 cytokines were assayed 6 h after CLP. Blood gas, wet/dry lung weight ratio, lung tissue histology for occurrence of ALI/ARDS, and survival were examined. Lastly, nuclear factor kappaB (NF-kappaB) activations, IkappaB-alpha degradations, phosphorylations of p38 MAPK, extracellular signal-regulated kinase 1/2, and c-Jun N-terminal kinase expressions were evaluated in lung tissue. Losartan treatment significantly attenuated TNF-alpha, IL-6, and IL-1beta 6 h after CLP. Furthermore, losartan prevented blood gas and histopathologic appearance of ALI/ARDS after sepsis and significantly improved survival. Finally, losartan given after sepsis led to inhibition of lung tissue NF-kappaB activation (P < 0.01 vs. CLP group), attenuated degradation of IkappaB-alpha, and inhibited phosphorylation of p38MAPK, extracellular signal-regulated kinase 1/2, and c-Jun N-terminal kinase, pathways critical for cytokine release. These data reveal that losartan exerts a protective effect on ALI/ARDS, and this protective effect may be dependent, at least in part, on NF-kappaB and MAPK mechanisms.
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PMID:Losartan prevents sepsis-induced acute lung injury and decreases activation of nuclear factor kappaB and mitogen-activated protein kinases. 1882 41

The morphological and functional integrity of the microcirculation is compromised in many cardiovascular diseases such as hypertension, diabetes, stroke, and sepsis. Angiotensin converting enzyme inhibitors (ACEi), which are known to favor bradykinin (BK) bioactivity by reducing its metabolism, may have a positive impact on preventing the microvascular structural rarefaction that occurs in these diseases. Our study was designed to test the hypothesis that BK, via B2 receptors (B2R), protects the viability of the microvascular endothelium exposed to the necrotic and apoptotic cell death inducers H(2)O(2) and LPS independently of hemodynamics. Expression (RT-PCR and radioligand binding) and functional (calcium mobilization with fura-2AM, and p42/p44MAPK and Akt phosphorylation assays) experiments revealed the presence of functional B2R in pig cerebral microvascular endothelial cells (pCMVEC). In vitro results showed that the cytocidal effects of H(2)O(2) and LPS on pCMVEC were significantly decreased by a BK pretreatment (MTT and crystal violet tests, annexin-V staining/FACS analysis), which was countered by the B2R antagonist HOE 140. BK treatment coincided with enhanced expression of the cytoprotective proteins COX-2, Bcl-2, and (Cu/Zn)SOD. Ex vivo assays on rat brain explants showed that BK impeded (by approximately 40%) H(2)O(2)-induced microvascular degeneration (lectin-FITC staining). The present study proposes a novel role for BK in microvascular endothelial protection, which may be pertinent to the complex mechanism of action of ACEi explaining their long-term beneficial effects in maintaining vascular integrity.
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PMID:Bradykinin protects against brain microvascular endothelial cell death induced by pathophysiological stimuli. 1978 24


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