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)

Sepsis results in hepatic "growth hormone (GH) resistance" with reductions in plasma IGF-I despite a two- to fourfold increase in circulating GH. In this study, we examine the effects of IL-1 on GH receptor (GHR) expression, GH signaling (via the JAK/STAT and MAPK pathways), and the induction of gene expression [IGF-I mRNA and serine protease inhibitor (Spi) 2.1] by GH in CWSV-1 hepatocytes. Incubation of cells with IL-1beta (10 ng/ml, 24 h) had no effect on the relative abundance of GHR or signaling proteins JAK2, STAT5b, and ERK1/2 in cell lysates. Baseline phosphorylation of GHR, JAK2, STAT5b, and ERK1/2 was minimal. After GH stimulation, tyrosine phosphorylation of GHR, JAK2, STAT5b, and ERK1/2 increased 2- to 10-fold. However, neither the time course nor the magnitude of GHR, JAK2, and ERK1/2 phosphorylation by GH were significantly altered by IL-1. The GH-induced translocation of STAT5b to the nucleus was not prevented by IL-1. Although phosphorylated STAT5 in nuclear extracts from GH + IL-1 cells was decreased by 24% (vs. controls) 15 min after GH stimulation, this did not result in reduced STAT5-DNA binding activity. Pretreatment with IL-1 did not significantly decrease IGF-I mRNA stability. We conclude that IL-1 only minimally affects the time course of JAK2/STAT5 and MAPK signaling by GH. Therefore, an inhibitory effect of IL-1 on IGF-I and Spi 2.1 mRNA synthesis by GH represents the most likely mechanism for IL-1-mediated GH resistance.
 ...
PMID:Interleukin-1 inhibits the induction of insulin-like growth factor-I by growth hormone in CWSV-1 hepatocytes. 1583 12

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.
 ...
PMID:Bigendothelin-1 via p38-MAPK-dependent mechanism regulates adult rat ventricular myocyte contractility in sepsis. 1595 56

Enhanced plasma levels of matrix metalloproteinase 9 (MMP-9) detected in patients with severe sepsis are thought to contribute to the development of organ dysfunction in endotoxemia. We have recently reported that peptidoglycan, the major wall component of gram-positive bacteria, increases MMP-9 levels in lung and liver and organ injury in the rat. Thus far, it is unclear whether MMP-9 is part of the septic response to peptidoglycan in human blood. The aim of the present study was to examine the regulation of MMP-9 by peptidoglycan in human leukocytes. The addition of peptidoglycan to whole human blood caused enhanced levels of MMP-9 after 1 h of incubation (306 vs. 75 ng/mL, P < or = 0.05) and onward, as measured by enzyme-linked immunoabsorbant assay. In neutrophil cultures, MMP-9 values increased significantly after 30 min of incubation with peptidoglycan (242 vs. 121 ng/mL, P < or = 0.05), whereas muramyl dipeptide had no effect. In contrast, adherent monocytes released insignificant amounts of MMP-9. To examine whether the released MMP-9 resulted from de novo synthesis, intracellular and secreted MMP-9 was measured during stimulation of neutrophils. The total MMP-9 values (the sum of intracellular and secreted MMP-9) before and after stimulation were mainly unaltered. The enhanced MMP-9 levels induced by peptidoglycan was attenuated by inhibitors of p38 mitogen-activated protein kinases (MAPK), (SB202190, 25 microM) and ERK1/2 (PD98059, 25 microM) and inhibitors of Src Tyrosine kinase (PP2, 5 microM) and PI3-K (LY294002, 25 microM).
 ...
PMID:Peptidoglycan of Staphylococcus aureus induces enhanced levels of matrix metalloproteinase-9 in human blood originating from neutrophils. 1613 59

Artemisia vestita Wall., a traditional Tibetan medicine, has wide clinical application for inflammatory diseases. However, its molecular mechanism of anti-inflammatory effect is poorly understood. In the present study, we investigated the anti-inflammatory activity and underlying mechanism of the ethanol extract from Artemisia vestita (AV-ext) on lipopolysaccharide (LPS)-induced sepsis. Pretreatment with AV-ext significantly decreased the levels of tumor necrosis factor-alpha (TNF-alpha) in serum and liver and lung tissues, and improved the survival of mice with experimental sepsis. AV-ext also remarkably reduced the expression levels of TNF-alpha, interleukin-1beta and cyclooxygenase-2 in LPS-stimulated RAW 264.7 macrophages and dose dependently suppressed the activation of mitogen-activated protein kinases (MAPKs), such as p38, extracellular signal-regulated kinase (ERK1/2) and c-Jun NH2-terminal kinase (JNK). Furthermore, pretreatment with AV-ext dose dependently inhibited the activation of nuclear factor-kappaB (NF-kappaB), as well as the degradation and phosphorylation of inhibitory kappaB (IkappaB) in LPS-activated RAW 264.7 macrophages. These results collectively reveal that AV-ext inhibits TNF-alpha release from macrophages by suppressing MAPK and NF-kappaB signaling pathways and suggest that AV-ext may be beneficial for the treatment of endotoxin shock or sepsis.
 ...
PMID:Ethanol extract from Artemisia vestita, a traditional Tibetan medicine, exerts anti-sepsis action through down-regulating the MAPK and NF-kappaB pathways. 1659 87

Delayed neutrophil apoptosis is characteristic of sepsis and may accentuate organ injury. It has been shown that PI-3K and MAPK pathways provide survival signaling in neutrophils. In this study, we demonstrate that neutrophils isolated from septic rats are resistant to apoptosis in comparison with the cells from normal animals. In contrast to normal serum, septic sera induced strong phosphorylation of AKT and p44/42 in neutrophils obtained from normal rats, resulting in marked resistance of these cells to apoptosis. Protection from apoptosis by septic sera was abrogated completely by inhibition of PI-3K and partially diminished by MEK inhibition. Increased neutrophil survival in septic rats was associated with increased levels of Bcl-xL in neutrophils and decreased levels of Bim expression. In vivo blockade of C5a in cecal ligation and puncture rats by anti-C5a antibody markedly restored the susceptibility of neutrophils to undergo apoptosis. C5a activated AKT and p44/42 and also enhanced X-linked inhibitor of apoptosis expression in neutrophils. LPS and C5a were able to induce Bcl-xL expression. Thus, neutrophil survival signals derived from effects of septic sera could be linked to activation of ERK1/2 and PI-3K, increased antiapoptotic protein expression, and ultimately, delayed neutrophil apoptosis.
 ...
PMID:In vivo regulation of neutrophil apoptosis by C5a during sepsis. 1699 61

Intestinal epithelial cells are subject to repetitive deformation during peristalsis and villous motility, whereas the mucosa atrophies during sepsis or ileus when such stimuli are abnormal. Such repetitive deformation stimulates intestinal epithelial proliferation via focal adhesion kinase (FAK) and extracellular signal-regulated kinases (ERK). However, the upstream mediators of these effects are unknown. We investigated whether Src and Rac1 mediate deformation-induced FAK and ERK phosphorylation and proliferation in human Caco-2 and rat IEC-6 intestinal epithelial cells. Cells cultured on collagen-I were subjected to an average 10% cyclic strain at 10 cycles/min. Cyclic strain activated Rac1 and induced Rac1 translocation to cell membranes. Mechanical strain also induced rapid sustained phosphorylation of c-Src at Tyr(418), Rac1 at Ser(71), FAK at Tyr(397) and Tyr(576), and ERK1/2 at Thr(202)/Tyr(204). The mitogenic effect of cyclic strain was blocked by inhibition of Src (PP2 or short interfering RNA) or Rac1 (NSC23766). Src or Rac1 inhibition also prevented strain-induced FAK phosphorylation at Tyr(576) and ERK phosphorylation but not FAK phosphorylation at Tyr(397). Reducing FAK using short interfering RNA blocked strain-induced mitogenicity and attenuated ERK phosphorylation but not Src or Rac1 phosphorylation. Src inhibition blocked strain-induced Rac1 phosphorylation, but Rac inhibition did not alter Src phosphorylation. Transfection of a two-tyrosine phosphorylation-deficient FAK mutant Y576F/Y577F prevented activation of cotransfected myc-ERK2 by cyclic strain. Repetitive deformation induced by peristalsis or villus motility may support the gut mucosa by a pathway involving Src, Rac1, FAK, and ERK. This pathway may present important targets for interventions to prevent mucosal atrophy during prolonged ileus or fasting.
 ...
PMID:Repetitive deformation activates focal adhesion kinase and ERK mitogenic signals in human Caco-2 intestinal epithelial cells through Src and Rac1. 1708 51

Severe injury deranges immune function and increases the risk of sepsis and multiple organ failure. Kupffer cells play a major role in mediating posttraumatic immune responses, in part via different Toll-like receptors (TLR). Although mitogen-activated protein kinases (MAPK) are key elements in the TLR signaling pathway, it remains unclear whether the activation of different MAPK are TLR specific. Male C3H/HeN mice underwent midline laparotomy (i.e., soft tissue injury), hemorrhagic shock (MAP approximately 35 mm Hg for 90 min), and resuscitation. Kupffer cells were isolated 2 h thereafter, lysed and immunoblotted with antibodies to p38, ERK1/2, or JNK proteins. In addition, cells were preincubated with specific inhibitors of p38, ERK1/2, or JNK MAPK followed by stimulation with the TLR2 agonist, zymosan; the TLR4 agonist, LPS; or the TLR9 agonist, CpG DNA. Cytokine (TNF-alpha, interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and KC) production was determined by cytometric bead array after 24 h in culture. MAPK activity as well as TNF-alpha, MCP-1, and KC production by Kupffer cells were significantly increased following trauma-hemorrhage. TLR4 activation by LPS stimulation increased the levels of all measured cytokines. CpG-stimulated TLR9 signaling increased TNF-alpha and IL-6 levels; however, it had no effect on chemokine production. Selective MAPK inhibition demonstrated that chemokine production was mediated via p38 and JNK MAPK activation in TLR2, -4, and -9 signaling. In contrast, TNF-alpha and IL-6 production was differentially regulated by MAPK depending on the TLR pathway stimulated. Thus, Kupffer cell TLR signaling employs different MAPK pathways in eliciting cytokine and chemokine responses following trauma-hemorrhage.
 ...
PMID:The role of MAPK in Kupffer cell toll-like receptor (TLR) 2-, TLR4-, and TLR9-mediated signaling following trauma-hemorrhage. 1711 77

TNF is implicated in the suppression of neutrophil apoptosis during sepsis. Multiple signaling pathways are involved in TNF-mediated antiapoptotic signaling; a role for the MAP kinases (MAPK), ERK1/2, and p38 MAPK has been suggested. Antiapoptotic signaling is mediated principally through TNF receptor-1 (TNFR-1), and the PKC isotype-delta (delta-PKC) is a critical regulator of TNFR-1 signaling. delta-PKC associates with TNFR-1 in response to TNF and is required for NFkappaB activation and inhibition of caspase 3. The role of delta-PKC in TNF-mediated activation of MAPK is not known. The purpose of this study was to determine whether the MAPK, ERK1/2, and p38 MAPK are involved in TNF antiapoptotic signaling and whether delta-PKC is a key regulator of MAPK activation by TNF. In human neutrophils, TNF activated both p38 MAPK and ERK1/2 principally via TNFR-1. The MEK1/2 inhibitors PD098059 and U0126, but not the p38 MAPK inhibitor SB203580, decreased TNF antiapoptotic signaling as measured by caspase 3 activity. A specific delta-PKC antagonist, V1.1delta-PKC-Tat peptide, inhibited TNF-mediated ERK1/2 activation, but not p38 MAPK. ERK1/2 inhibition did not alter recruitment of delta-PKC to TNFR-1, indicating delta-PKC is acting upstream of ERK1/2. In HL-60 cells differentiated to a neutrophilic phenotype, delta-PKC depletion by delta-PKC siRNA resulted in inhibition of TNF mediated ERK1/2 activation but not p38 MAPK. Thus, ERK1/2, but not p38 MAPK, is an essential component of TNF-mediated antiapoptotic signaling. In human neutrophils, delta-PKC is a positive regulator of ERK1/2 activation via TNFR-1 but has no role in p38 MAPK activation.
 ...
PMID:Regulation of TNF mediated antiapoptotic signaling in human neutrophils: role of delta-PKC and ERK1/2. 1713 60

Electrical coupling along the endothelium is central in the arteriolar conducted response and in control of vascular resistance. It has been shown that exposure of endothelium to lipopolysaccharide (LPS, an initiating factor in sepsis) reduces intercellular communication in vitro and in vivo. The molecular basis for this reduction is not known. We examined the effect of LPS on electrical coupling in monolayers of cultured mouse microvascular endothelial cells (MMEC) derived from the mouse hindlimb skeletal muscle. To assess coupling, we measured the spread of electrical current injected into the monolayer and computed the monolayer intercellular resistance (inverse measure of coupling). LPS (10 microg/ml, 1 h) reduced coupling (i.e., increased resistance) in MMEC isolated from wild-type, connexin37 (Cx37) null and Cx43(G60S) (nonfunctional mutant) mice, but not in MMEC derived from Cx40 null mice. LPS also activated JNK1/2, p38 and ERK1/2 MAP kinases. Pretreatment of WT monolayers with ERK1/2 inhibitor U0126 (20 microM, 1 h) prevented the LPS-induced decrease in coupling, while inhibition of JNK1/2 with SP600125 (20 microM, 1 h) and p38 with a p38 inhibitor (10 nM, 1 h) had no effect. Furthermore, inhibition of tyrosine kinases with PP-2 (10 nM, 1 h), activation of PKA by 8-bromo-cAMP (1 mM, 5 min), and activation of PKC by bryostatin-2 (10 nM, 1 h) also prevented the reduction in coupling. We propose that LPS reduces inter-endothelial electrical coupling via tyrosine-, ERK1/2-, PKA-, and PKC-dependent signaling that targets Cx40. We suggest that this mechanism contributes to compromised arteriolar function following LPS exposure.
 ...
PMID:Lipopolysaccharide reduces electrical coupling in microvascular endothelial cells by targeting connexin40 in a tyrosine-, ERK1/2-, PKA-, and PKC-dependent manner. 1714 6

Tissue factor (TF) is the primary initiator of coagulation, and the TF pathway mediates signaling through protease-activated receptors (PARs). In sepsis, TF is up-regulated as part of the proinflammatory response in lipopolysaccharide (LPS)-stimulated monocytes leading to systemic coagulation activation. Here we demonstrate that TF cytoplasmic domain-deleted (TF(Delta CT)) mice show enhanced and prolonged systemic coagulation activation relative to wild-type upon LPS challenge. However, TF(Delta CT) mice resolve inflammation earlier and are protected from lethality independent of changes in coagulation. Macrophages from LPS-challenged TF(Delta CT) mice or LPS-stimulated, in vitro-differentiated bone marrow-derived macrophages show increased TF mRNA and functional activity relative to wild-type, identifying up-regulation of macrophage TF expression as a possible cause for the increase in coagulation of TF(Delta CT) mice. Increased TF expression of TF(Delta CT) macrophages does not require PAR2 and is specific for toll-like receptor, but not interferon gamma receptor, signaling. The presence of the TF cytoplasmic domain suppresses ERK1/2 phosphorylation that is reversed by p38 inhibition leading to enhanced TF expression specifically in wild-type but not TF(Delta CT) mice. The present study demonstrates a new role of the TF cytoplasmic domain in an autoregulatory pathway that controls LPS-induced TF expression in macrophages and procoagulant responses in endotoxemia.
 ...
PMID:Regulation of macrophage procoagulant responses by the tissue factor cytoplasmic domain in endotoxemia. 1733 47


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>