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)

Inflammatory stimulation of the liver is known to induce nitric oxide (NO) biosynthesis. NO can interfere with the activity of a number of enzymes important to cellular metabolism. This study was carried out to investigate the influence of NO on rat hepatocyte glucose output and urea production. Induction of NO synthesis by incubation with a combination of cytokines and lipopolysaccharide led to a 48.8 +/- 2.4% inhibition of glucose output and to a 45.0 +/- 6.4% suppression of urea production. Inhibition of NO synthesis with NG-monomethyl-L-arginine was able to totally prevent these effects. High concentrations of L-arginine overcame the inhibition of urea production caused by endogenous NO synthesis. Exposure of HC to NO donors resulted in a concentration-dependent inhibition of glucose output, without having any effect on urea production. Hepatocellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity was also found to be inhibited by endogenously produced NO (33.5 +/- 5.2%), as well as by exogenously applied NO. However, an exact correlation between GAPDH activity and glucose output could not be established. These data indicate that NO biosynthesis may contribute to the development of hepatic dysfunction in chronic sepsis.
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PMID:Hepatocyte nitric oxide biosynthesis inhibits glucose output and competes with urea synthesis for L-arginine. 784 Feb 3

1. Induction of nitric oxide synthase (iNOS) results in overproduction of nitric oxide (NO), which may be a principal cause of the massive vasodilatation and hypotension observed in septic shock. Since NO-induced vasorelaxation is mediated via the soluble isoform of guanylate cyclase (sGC), the regulation of sGC activity during shock is of obvious importance, but yet poorly understood. The aim of the present study was to investigate the activation of sGC by sodium nitroprusside (SNP) before and after exposure of rat aortic smooth muscle cells to endotoxin (LPS) or interleukin-1 beta (IL-1 beta). 2. Exposure of rat aortic smooth muscle cells to SNP (10 microM) elicited up to 200 fold increases in cyclic GMP. This effect was attenuated by 30-70% in IL-1 beta- or LPS-pretreated cells, in a pretreatment time-and IL-1 beta- or LPS-concentration-dependent manner. When, however, cells were exposed to IL-1 beta or LPS and then stimulated with the particulate guanylate cyclase activator, atriopeptin II, no reduction in cyclic GMP accumulation was observed. 3. Pretreatment of rats with LPS (5 mg kg-1, i.v.) for 6 h led to a decrease in aortic ring SNP-induced cyclic GMP accumulation. 4. The IL-1 beta-induced reduction in SNP-stimulated cyclic GMP accumulation in cultured cells was dependent on NO production, as arginine depletion abolished the downregulation of cyclic GMP accumulation in response to SNP. 5. Reverse-transcriptase-polymerase chain reaction analysis revealed that the ratio of steady state mRNA for the alpha, subunit of sGC to glyceraldehyde phosphate dehydrogenase was decreased in LPS- or IL-1 beta-treated cells, as compared to vehicle-treated cells. 6. Protein levels of the alpha 1 sGC subunit remained unaltered upon exposure to LPS or IL-1 beta, suggesting that the early decreased cyclic GMP accumulation in IL-1 beta- or LPS-pretreated cells was probably due to reduced sGC activation. Thus, the observed decreased responsiveness of sGC to NO stimulation following cytokine or LPS challenge may represent an important homeostatic mechanism to offset the extensive vasodilatation seen in sepsis.
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PMID:Downregulation of nitrovasodilator-induced cyclic GMP accumulation in cells exposed to endotoxin or interleukin-1 beta. 883 57

The use of digoxigenin (DIG)- and biotin-labelled dsDNA probes to detect TNFalpha-mRNA accumulation in human peripheral blood mononuclear cells (PBMC) and isolated monocytes is described. The fragment of the glyceraldehyde-3-phosphate dehydrogenase GAPDH-cDNA was used as a control probe. The hybridization signals were detected by staining with fluorescein isothiocyanate (FITC)-labelled anti-DIG antibody and avidin-FITC, respectively. The cells were stimulated in vitro with lipopolysaccharide (LPS) for 0.5-6 h. The TNFalpha-mRNA was detected in monocytes 1 h after stimulation with LPS, and the highest accumulation was seen around 2 h. The TNFalpha-mRNA in stimulated PBMC was detected at the lower level peaking around 4 h. The TNFalpha-mRNA accumulation was lower in lymphocytes than in monocytes when PBMC were studied. There was no difference in the level of GAPDH-mRNA between unstimulated and stimulated cells. Finally, an enhanced accumulation of TNFalpha-mRNA was observed in PBMC from some patients with sepsis or cancer. Thus, this study shows that cytokine gene expression may be detected in cells ex vivo. This opens the possibility of studying the level of cytokine gene activation in PBMC of patients with diseases where the role of cytokines in their pathophysiology is implicated.
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PMID:Detection of cytokine gene expression in human monocytes and lymphocytes by fluorescent in situ hybridization in cell suspension and flow cytometry. 985 37

Although protein carbonyl formation is an index of oxidative stress in skeletal muscles, the exact proteins, which undergo oxidation in these muscles, remain unknown. We used 2D electrophoresis, immunoblotting, and mass spectrometry to identify carbonylated proteins in the diaphragm in septic animals. Rats were injected with saline (control) or Escherichia coli lipopolysaccharides (LPS) and killed after various intervals. Diaphragm protein carbonylation increased significantly and peaked 12 h after LPS injection, and it was localized both inside muscle fibers and in blood vessels supplying muscle fibers. Aldolase A, glyceraldehyde 3-phosphate dehydrogenase, enolase 3beta, mitochondrial and cytosolic creatine kinases, alpha-actin, carbonic anyhdrase III, and ubiquinol-cytochrome c reductase were all carbonylated in septic rat diaphragms. In addition, we found significant negative correlations between the intensity of carbonylation and creatine kinase and aldolase activities. We conclude that glycolysis, ATP production, CO2 hydration, and contractile proteins are targeted by oxygen radicals inside the diaphragm during sepsis.
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PMID:Protein carbonyl formation in the diaphragm. 1547 39

Streptococcus pyogenes is an important pathogen that causes pharyngitis, sepsis, and rheumatic fever. Cell-associated streptococcal C5a peptidase (ScpA) protects S. pyogenes from phagocytosis and has been suggested to interrupt host defenses by enzymatically cleaving complement C5a, a major factor in the accumulation of neutrophils at sites of infection. How S. pyogenes recognizes and binds to C5a, however, is unclear. We detected a C5a-binding protein in 8 M urea extracts of S. pyogenes by ligand blotting using biotinylated C5a. Searching of genome databases showed that the C5a-binding protein is identical to the streptococcal plasmin receptor (Plr), also known as streptococcal surface dehydrogenase (SDH) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In the present study we identified a novel function of this multifunctional protein. Western blotting and immunofluorescence microscopy with anti-Plr/SDH/GAPDH showed that Plr/SDH/GAPDH is located on the bacterial surface and released into the culture supernatant. Next, we examined whether the streptococcal Plr/SDH/GAPDH inhibits the biological effects of C5a on human neutrophils. We found that soluble Plr/SDH/GAPDH inhibits C5a-activated chemotaxis and H2O2 production. Furthermore, our results suggested that soluble Plr/SDH/GAPDH captures C5a, inhibiting its chemotactic function. Also, cell-associated Plr/SDH/GAPDH and ScpA were both necessary for the cleavage of C5a on the bacterial surface. Together, these results indicate that the multifunctional protein Plr/SDH/GAPDH has additional functions that help S. pyogenes escape detection by the host immune system.
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PMID:Multifunctional glyceraldehyde-3-phosphate dehydrogenase of Streptococcus pyogenes is essential for evasion from neutrophils. 1656 20

Group B Streptococcus (GBS) is an opportunistic organism that can harmlessly colonize the human gut, vagina, and rectum but can also cause pneumonia, sepsis, and meningitis in neonates born to colonized mothers. We have shown previously that growth rate and oxygen level regulate the ability of GBS to invade eukaryotic cells in vitro. Herein we extend and expand on these observations to show that GBS type V, an emergent serotype, grown in a chemostat at a cell mass-doubling time (t(d)) of 1.8 h with oxygen invaded human ME-180 cervical epithelial cells in large numbers compared with those grown at the same t(d) without oxygen or at a slower t(d) of 11.0 h. The fact that several GBS type V cell wall-associated and membrane proteins were expressed exclusively under the invasive growth condition prompted an investigation, using genomics and proteomics, of all upregulated genes and proteins. Several proteins with potential roles in adherence were identified, including an undefined surface antigen (SAG1350), a lipoprotein (SAG0971), penicillin-binding protein 2b (SAG0765), glyceraldehyde-3-phosphate dehydrogenase (SAG0823), and an iron-binding protein (SAG1007). Mouse antisera to these five proteins inhibited binding of GBS type V to ME-180 cells by > or =85%. Recombinant undefined surface antigen (SAG1350), lipoprotein (SAG0971), and penicillin-binding protein 2b (SAG0765) each bound to ME-180 cells in a dose-dependent fashion, confirming their ability to act as ligands. Collectively, these data increase the number of potential GBS adherence factors and also suggest a role for these surface-associated proteins in initial pathogenic events.
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PMID:Transcriptional and proteomic profiles of group B Streptococcus type V reveal potential adherence proteins associated with high-level invasion. 1721 Jun 64

One of the clinical characteristics associated with septic shock is heart failure. Several lines of evidence indicate that functional consequences of heart failure in septic shock are linked to the activated NO-cyclic guanosine monophosphate (NO-cGMP) pathway. We have previously shown that the high-affinity cGMP export transporter, multidrug resistance protein 5 (MRP5), is expressed in the heart, which modulates intracellular concentrations and, hence, the effects of cGMP. Thus, modified expression of cardiac MRP5 in septic shock can alter cGMP concentrations and contribute to the development of heart failure. We therefore investigated MRP5 expression in the heart using two established murine models of septic shock (intraperitoneal LPS injection and surgical implantation of a stent into the ascending colon, resulting in a multibacterial peritonitis [CASP, colon ascendens stent peritonitis] in C57BL/6N mice, respectively; n = 38). Cardiac MRP5 was assessed by quantitative polymerase chain reaction and immunofluorescence. The protein was localized in the endothelial wall, smooth muscle, and cardiac myocytes. MRP5 mRNA expression was significantly reduced compared with controls both in the LPS (31.9 +/- 16.8 x 10(-4) vs. 54.1 +/- 14.8 x 10(-4), P = 0.025) and CASP model (18.3 +/- 9.4 x 10(-4) vs. 42.8 +/- 12.1 x 10(-4), P = 0.009; MRP5/glyceraldehyde 3-phosphate dehydrogenase copy numbers, respectively). In parallel, IL-6 plasma levels were significantly increased in both models. Incubation of cultured murine cardiomyocytes (HL1) with 5 ng/mL IL-6 resulted in decreased expression of MRP5 (54% of control), as did incubation of the cells with serum from septic mice (LPS serum, 22% of control; CASP serum, 11% of control). In conclusion, cardiac expression of the cGMP export transporter MRP5 is decreased in two murine models of septic shock, most likely by a transcriptional mechanism. Reduced cGMP export as a consequence of decreased MRP5 expression can attenuate heart failure in sepsis.
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PMID:Sepsis affects cardiac expression of multidrug resistance protein 5 (MRP5, ABCC5), an ABC-type CGMP export pump. 1758 84

Marked contractile failure of the heart is important in both sepsis and endotoxemia, and an understanding of its molecular basis is lacking. We investigated changes in rat myocardial proteins in endotoxemia. Rats were injected with lipopolysaccharide (LPS) and sacrificed 3, 6, 12 and 24 h later. Control rats were injected with a vehicle and sacrificed 6 h later.In the LPS-6 h and LPS-12 h groups, plasma nitrites (NO(x)(-)), were elevated while mean arterial blood pressure (MAP) was depressed as compared to the controls. In the LPS-24 h group, plasma (NO(x)(-)) was returning to the base level whereas MAP was still decreased in comparison to the control group. Six proteins showed changes between groups. All six proteins were decreased in abundance in the LPS-6 h group vs. control. Of the six proteins, three were normalized in the LPS-24 h group: albumin, heat shock protein 27 and triosephosphate isomerase. The three other did not normalize: glyceraldehyde 3-phosphate dehydrogenase, H+-transporting ATP synthase and dienoyl-CoA isomerase. A decrease in abundance of metabolic enzymes may be the result of mitochondrial damage and this decrease could play a protective role against the hypermetabolic state associated with the later stages of sepsis and endotoxemia.
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PMID:Proteomics analysis of changes in myocardial proteins during endotoxemia. 1936 82

Group B Streptococcus (GBS) is the leading cause of neonatal pneumonia, septicemia, and meningitis. We have previously shown that in adult mice GBS glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an extracellular virulence factor that induces production of the immunosuppressive cytokine interleukin-10 (IL-10) by the host early upon bacterial infection. Here, we investigate whether immunity to neonatal GBS infection could be achieved through maternal vaccination against bacterial GAPDH. Female BALB/c mice were immunized with rGAPDH and the progeny was infected with a lethal inoculum of GBS strains. Neonatal mice born from mothers immunized with rGAPDH were protected against infection with GBS strains, including the ST-17 highly virulent clone. A similar protective effect was observed in newborns passively immunized with anti-rGAPDH IgG antibodies, or F(ab')(2) fragments, indicating that protection achieved with rGAPDH vaccination is independent of opsonophagocytic killing of bacteria. Protection against lethal GBS infection through rGAPDH maternal vaccination was due to neutralization of IL-10 production soon after infection. Consequently, IL-10 deficient (IL-10(-/-)) mice pups were as resistant to GBS infection as pups born from vaccinated mothers. We observed that protection was correlated with increased neutrophil trafficking to infected organs. Thus, anti-rGAPDH or anti-IL-10R treatment of mice pups before GBS infection resulted in increased neutrophil numbers and lower bacterial load in infected organs, as compared to newborn mice treated with the respective control antibodies. We showed that mothers immunized with rGAPDH produce neutralizing antibodies that are sufficient to decrease IL-10 production and induce neutrophil recruitment into infected tissues in newborn mice. These results uncover a novel mechanism for GBS virulence in a neonatal host that could be neutralized by vaccination or immunotherapy. As GBS GAPDH is a structurally conserved enzyme that is metabolically essential for bacterial growth in media containing glucose as the sole carbon source (i.e., the blood), this protein constitutes a powerful candidate for the development of a human vaccine against this pathogen.
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PMID:Inhibition of IL-10 production by maternal antibodies against Group B Streptococcus GAPDH confers immunity to offspring by favoring neutrophil recruitment. 2211 50

Riemerella anatipestifer is the causative agent of septicemia anserum exsudativa in ducks. Its pathogenesis and virulence factors are still unclear. The glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an anchorless and multifunctional protein on the surface of several pathogenic microorganisms, is involved in virulence and adhesion. Whether homologs of GAPDH exist, and display similar characteristics in R. anatipestifer (RaGAPDH) has not been determined. In our research, the RaGAPDH activity from various R. anatipestifer isolates was confirmed. Twenty-two gapdh genes from genomic DNA of R. anatipestifer isolates were cloned and sequenced for phylogenetic analysis. The distribution of RaGAPDH in R. anatipestifer CZ2 strain was confirmed by antisera to recombinant RaGAPDH. The ability of purified RaGAPDH to bind host proteins was analyzed by solid-phase ligand-binding assay. Results revealed that all R. anatipestifer isolates showed different levels of GAPDH activity except four strains, which contained a gapdh-like gene. The gapdh of R. anatipestifer, which is located phylogenetically in the same branch as enterohemorrhagic Escherichia coli (EHEC), belonged to class I GAPDH, and encoded a 36.7-kDa protein. All RaGAPDH-encoding gene sequences from field isolates of R. anatipestifer displayed 100% homology. The RaGAPDH localized on the extracellular membrane of several R. anatipestifer strains. Further, it was released into the culture medium, and exhibited GAPDH enzyme activity. We also confirmed the binding of RaGAPDH to plasminogen and fibrinogen. These results demonstrated that GAPDH was present in R. anatipestifer, although not in all strains, and that RaGAPDH might contribute to the microorganism's virulence.
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PMID:A homolog of glyceraldehyde-3-phosphate dehydrogenase from Riemerella anatipestifer is an extracellular protein and exhibits biological activity. 2518 32


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