OBJECTIVETo compare the ability of the polysaccharide from various Porphyromonas gingivalis (Pg) type and clinical strains in inducing THP-1 cells to produce cytokines interleukin(IL)-1β, IL-8, and tumor necrosis factor(TNF)-α, in order to analyze the immunogenicity of Pg polysaccharide components and the virulence-associated factors of this periodontal pathogen.

METHODSThe bacterial polysaccharide was extracted from high virulent Pg strains, W83, SJD2, SJD12 and low virulent Pg, ATCC33277, SJD4, SJD5, and SJD11 by phenol-water extraction. The extracted polysaccharide was used to stimulate the THP-1 cells with different simulation periods and doses. The level of the cytokines, including IL-1β,IL-8 and TNF-α in the cell culture suspension was measured by enzyme-linked immunosorbent assay(ELISA).

RESULTSThe polysaccharide extraction of Pg strains was composed of lipopolysaccharide(LPS) and capsular polysaccharide. The secretion of IL-1β, IL-8 and TNF-α, produced by the THP-1 cells showed in a time- and dose-dependent manner in the medium containing 10% fetal bovine serum. The level of these cytokines of the high virulent strains was higher than that of the low virulent strains in medium containing 1% fetal bovine serum.Four hours after stimulation with polysaccharide extracted from high virulent strains, the levels of IL-1β,IL-8, and TNF-α in the cell suspension were (1 639 ± 497), (1 648 ± 513) and (140 ± 48) µg/L, respectively, whereas for low virulent strains, the levels of IL-1β, IL-8, and TNF-α were (773 ± 382), (892 ± 400) and (67 ± 33) µg/L, respectively.

CONCLUSIONSPolysaccharide extracted from Pg could induced the THP-1 cells to secrete the cytokines of IL-1β, IL-8 and TNF-α. The level of the cytokines produced by the THP-1 cells associates with the bacterial virulent properties.

Cytokines ; metabolism ; Interleukin-1beta ; Interleukin-8 ; Lipopolysaccharides ; physiology ; Porphyromonas gingivalis ; metabolism ; Tumor Necrosis Factor-alpha

Xanthomonas campestris pv. campestris (Xcc), the pathogenic agent of black rot disease in cruciferous plants, produces large amount of extracellular polysaccharide (EPS), which has found wide applications in industry. For the great commercial value of the xanthan gum, many of the genes involved in EPS biosynthesis have been cloned and the mechanism of EPS biosynthesis also has been studied. In order to clone genes involved in EPS biosynthesis, Xcc wild-type strain 8004 was mutagenized with transposon Tn5 gusA5, and a number of EPS-defective mutants were isolated in our previous work. The Tn5 gusA5 inserted sites of these mutants were located by using thermal asymmetric interlaced PCR, and results showed that two EPS-defective mutants were insertion mutants of the gene wxcA which involved in lipopolysaccharide (LPS) biosynthesis. The gene wxcA involved in lipopolysaccharide biosynthesis but dose not extracellular polysaccharide in others' report. wxcA::Tn5 gusA5 mutant 021C12, the polar mutant, was complemented with recombinant plasmid pLATC8570 harboring an intact wxcA gene in this work, but the yield of EPS of the wxcA::Tn5 gusA5 mutant was not restored. In order to identify the function of wxcA gene of Xcc 8004 strain, the gene wxcA was deleted by gene replacement strategy, and the no-polar mutant of wxcA was obtained. DeltawxcA mutant strain, named Xcc 8570, was confirmed by using both PCR and southern analysis. Beside the LPS biosynthesis of deltawxcA mutant was affected, The EPS yield of deltawxcA mutant strain reduced by 50% as compared with the wild-type strain 8004. DeltawxcA mutant could be complemented in trans with the intact wxcA gene, and the EPS yield of the mutant was restored. The combined data showed that wxcA gene not only involved in LPS biosynthesis but also EPS yield in Xcc 8004 strain.
Cell Proliferation ; Genes, Bacterial ; physiology ; Lipopolysaccharides ; biosynthesis ; Mutation ; Polysaccharides, Bacterial ; biosynthesis ; Xanthomonas campestris ; genetics

The purpose of this study is to provide a culture for mouse bone marrow-derived macrophages (BMDM) and peritoneal macrophages (PM) and to characterize their molecular and cellular biology. The cell number and purity from the primary culture were assessed by cell counter and flow cytometry, respectively. Morphological features were evaluated by inverted microscope. Phagocytosis by macrophages was detected by the neutral red dye uptake assay. Phenotypic markers were analyzed by real-time fluorescent quantitative PCR. Our results show that the cell number was much higher from culture of BMDM than PM, while there was no significant difference regarding the percentage of F4/80+CD11b+ cells (98.30%±0.53% vs. 94.83%±1.42%; P>0.05). The proliferation rate of BMDM was significantly higher than PM in the presence of L929 cell conditioned medium, by using CCK-8 assay. However, PM appeared to adhere to the flask wall and extend earlier than BMDM. The phagocytosis capability of un-stimulated BMDM was significantly higher than PM, as well as lipopolysaccharide (LPS)-stimulated BMDM, except the BMDM stimulated by low dose LPS (0.1 μg/mL). Furthermore, Tnfα expression was significantly higher in un-stimulated BMDM than PM, while Arg1 and Ym1 mRNA expression were significantly lower than PM. The expression difference was persistent if stimulated by LPS+IFN-γ or IL-4. Our data indicate that bone marrow can get larger amounts of macrophages than peritoneal cavity. However, it should be aware that the molecular and cellular characteristics were different between these two culture systems.
Animals ; Bone Marrow Cells ; physiology ; Cells, Cultured ; Culture Media, Conditioned ; Lipopolysaccharides ; metabolism ; Macrophages ; classification ; physiology ; Mice ; Phagocytosis

OBJECTIVE: To investigate effects of antioxidant stress protein heme oxygenase-1 (HO-1) on lipopolysaccharide (LPS)-induced endoplasmic reticulum stress (ERS) of rat hepatocytes. METHODS: The BRL cells (rat hepatocyte cell line) were cultured. The hepatocytes were treated with LPS, LPS+HO-1 siRNA, HO-1 siRNA and PBS solution, respectively. The cell viability was measured by trypan blue exclusion test. The apoptosis cells were detected by the fluorescent dye Hoechst 33258. Expressions of GRP78, CHOP, caspase-12 and HO-1 were detected by Western blotting. RESULTS: LPS caused an increase of HO-1 protein expression of rat hepatocytes in a dose-dependent and time-dependent manner, a up-regulation of GRP78, CHOP and caspase-12, a decrease in cell viability, and an increase in apoptosis rate of hepatocytes. Pretreatment of HO-1 siRNA inhibited the up-regulation of LPS-induced HO-1, however, aggravated ERS and cellular injury. CONCLUSION HO-1 inhibites ERS-mediated cellular injury of rat hepatocytes induced by LPS.
Animals ; Apoptosis/physiology* ; Endoplasmic Reticulum/metabolism* ; Endoplasmic Reticulum Stress/physiology* ; Heme Oxygenase-1/pharmacology* ; Hepatocytes/metabolism* ; Lipopolysaccharides/pharmacology* ; Rats

Alcoholic liver disease is a leading cause of morbidity and liver-related death worldwide. Intestinal bacterial overgrowth and dysbiosis induced by ethanol ingestion play an important role in the pathogenesis of alcoholic liver disease. After exposure to alcohol in the lumen, enteric bacteria alter their metabolism and thereby disturb intestinal homeostasis. Disruption of the mucosal barrier results in the translocation of microbial products that contribute to liver disease by inducing hepatic inflammation. In this review, we will discuss the effects of alcohol on the intestinal microbiome, and in particular, its effects on bacterial metabolism, bacterial translocation and ecological balance. A better understanding of the interactions among alcohol, the host and the microbiome will reveal new targets for therapy and lead to new treatments.
Bacterial Translocation/physiology ; Central Nervous System Depressants/metabolism ; Ethanol/metabolism ; Humans ; Intestines/*microbiology ; Lipopolysaccharides/physiology ; Liver Diseases, Alcoholic/*microbiology ; Microbiota/*physiology ; Permeability

OBJECTIVETo investigate the role of nuclear factor kappa B (NF-kappaB) pathway inhibition in lipopolysaccharide (LPS)-stimulated apoptosis of polymorphonuclear neutrophils (PMNs).

METHODSRats with acute lung injury induced by LPS intratracheal instillation and cultured human venous PMNs were studied. Pyrrolidine dithiocarbamate (PDTC) and gliotoxin were used as NF-kappaB inhibitors. Additionally, to explore the role of extracellularly regulated protein kinase as an upstream signal in NF-kappaB pathway on regulating LPS-stimulated PMN apoptosis, PD098059, the specific inhibitor of extracellularly regulated protein kinase, was also applied. The lung injury was determined by protein content and PMN numbers in bronchoalveolar lavage fluid. PMN apoptosis was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) end labeling and DNA fragmentation. IkappaBalpha degradation was analyzed by Western blot. NF-kappaB DNA binding activity was detected by an electrophoretic mobility shift assay.

RESULTS(1) The increase of protein content and PMN numbers in bronchoalveolar lavage fluid induced by LPS (100 micro g per rat) intratracheal instillation were alleviated by PDTC (50, 100, or 200 mg/kg, i.p.) in a dose-dependent manner. (2) PMNs apoptosis in vivo or in vitro was delayed by LPS, and accelerated by PDTC, gliotoxin or PD098059 pretreatment. (3) IkappaBalpha degradation and increased NF-kappaB DNA binding activity mediated by LPS were inhibited by PDTC, gliotoxin or PD098059 pretreatment.

CONCLUSIONInhibition of either NF-kappaB itself or the upstream signals in NF-kappaB pathway such as extracellularly regulated protein kinases has therapeutic effect on LPS-induced acute lung injury, in which the dysregulation of PMN apoptosis plays an important role.

Animals ; Apoptosis ; Cells, Cultured ; Humans ; Lipopolysaccharides ; pharmacology ; NF-kappa B ; physiology ; Neutrophils ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; physiology

AIMTo investigate the effects of endothelin-1 (ET-1) and nitric oxide (NO) on lipopolysaccharide(LPS)-induced myocardial dysfunction, and explore the related underlying mechanisms.

METHODSExperimental septic model was established by intraperitoneal injection of LPS (10 mg x kg(-1)). The study was carried out on the isolated rat hearts to determine the roles of ET-1 and NO in the effect of LPS on the cardiac contractility and on the isolated rat ventricular myocytes model to observe the [Ca2+]i homeostasis in cardiac myocytes.

RESULTS(1) The levels of serum NO2-/NO3- and plasma ET-1 were markedly increased by LPS treatment for 4 hours. (2) LPS induced the decrease in rate-pressure product (RPP), and increase in left ventricular end-diastolic pressure (LVEDP) in the isolated perfused rat hearts. Pretreatment with either aminoguanidine (AMG) (100 mg x kg(-1), i.p.) or BQ-123 (1 mg x kg(-1), i.p.) partially attenuated LPS-induced myocardial depression. When these two drugs were simultaneously given, myocardial depression elicited by LPS was almost abolished. (3) LPS significantly decreased the amplitude of caffeine induced [Ca2+]i transients compared to the control cells. The activity of SR Ca22+ -ATPase was significantly decreased in the cardiac myocytes from LPS-treated rats. Single pretreatment with either AMG or BQ-123 did not attenuate the impairment of SR Ca2+ -ATPase induced by LPS.

CONCLUSIONET-1 and NO mediate myocardial dysfunction in hearts isolated and decrease [Ca2+]i transients in cardiac myocytes from LPS-treated rats. But neither ET-1 nor NO participates in the impairment of SR Ca2+ -ATPase induced by LPS.

Animals ; Depression, Chemical ; Endothelin-1 ; physiology ; Lipopolysaccharides ; toxicity ; Male ; Myocardial Contraction ; drug effects ; physiology ; Nitric Oxide ; physiology ; Rats ; Rats, Sprague-Dawley ; Shock, Septic ; chemically induced ; physiopathology

OBJECTIVETo observe the change in vital signs and arterial blood gas in Lipopolysaccharide (LPS)-injected heat exposed rats.

METHODSMale pathogen-free Wistar rats were randomly assigned to the following groups: saline-injected normothermic control (C-Group), saline-injected heat exposed (H-Group), LPS-injected normothermic control (L-Group), LPS-injected heat exposed (HL-Group). Rectal temperature (Tr), heart rate (HR), mean arterial pressure (MAP), arterial blood gas were continually monitored.

RESULTS(1) The rats in HL-Group displayed significantly high values of Tr (43.04 degrees C +/- 0.11 degrees C) and HR [(660 +/- 42) beats/min] and low values of MAP [(49.0 +/- 3.5) mm Hg] compared with C-Group. There was a significant difference in the values of Tr, HR, and MAP between HL-Group and L-Group and in the values of HR and MAP between HL-Group and H-Group. (2) The values of PaO(2), HCO(3)(-), PaCO(2) were significantly lower than those in C-Group at 40 min after LPS-injected heat stress. At 120 min, the PaO(2) [(11.59 +/- 1.11) kPa], HCO(3)(-) [(10.42 +/- 1.06) mmol/L], PaCO(2) [(2.82 +/- 0.81) kPa] in HL-Group were significantly lower than those in L-Group. A significant difference in the values of HCO(3)(-) and PaCO(2) between HL-Group and H-Group was also observed.

CONCLUSIONLPS-injected heat stress primes the rat to advance and augment the change in vital signs, arterial blood gas, and systemic inflammatory response syndrome.

Animals ; Blood Gas Analysis ; Blood Pressure ; physiology ; Body Temperature ; physiology ; Heart Rate ; physiology ; Heat Stress Disorders ; blood ; physiopathology ; Lipopolysaccharides ; toxicity ; Male ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVETo investigate the effect of Ca(2+) on lipopolysaccharide (LPS)-induced NF-kappa B activation in pancreatic acinar cells and the role of NF-kappa B in LPS-induced acinar cell injury.

METHODSMale rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to varying concentrations of LPS (from 1 to 20 mg/L) in the presence or absence of EGTA. At various time points (30 minutes, 1 hour, 2 hours, 4 hours and 10 hours) after treatment with the agents, cell viability was determined by MTT. Nuclear translocation of NF-kappa B's subunit p65 was visualized by immunofluorescence staining and nuclei protein was extracted to perform EMSA which was used to assay the activity of NF-kappa B binding to the DNA sequence containing the recognition site of NF-kappa B.

RESULTSLPS induced cell damage in a time- and concentration-dependent manner while EGTA attenuated LPS-induced cell damage (P < 0.05). NF-kappa B p65 immunofluorescence staining had increased intensity in the cytoplasm and indicated that nuclear translocation occurred within 30 minutes and its zenith was reached at 1 hour after LPS (10 mg/L) treatment. Testing of NF-kappa B DNA binding activity showed the same alteration phase as p65 immunofluorescence staining. NF-kappa B activation preceded the pathological alteration of pancreatic acinar cells. The Ca(2+) chelator EGTA inhibited LPS-induced NF-kappa B activation.

CONCLUSIONSNF-kappa B activation is an important early event in LPS-induced injury to pancreatic acinar cells. Ca(2+) is an important mediator in the process of LPS-induced NF-kappa B activation.

Animals ; Calcium ; pharmacology ; Lipopolysaccharides ; pharmacology ; Male ; NF-kappa B ; physiology ; Pancreas ; cytology ; drug effects ; Rats ; Rats, Sprague-Dawley

AIMTo study the possibility that responses of fever and discharge of neurons in PVN to intraperitoneal administration of LPS are mediated by vagal afferents.

METHODSRectal temperature of rat was detected by digital temperature detecting instrument. Glass micropipette placed in PVN was used to record unit discharges of neurons in it, before and after LPS was injected into PVN in normal rats and vagotomy rats.

RESULTSThe rectal temperature change value in vagotomy LPS group was significantly decreased compared with that in sham LPS group, and there was striking difference between them (P < 0.05). The discharges of neurons in PVN was increased in the normal rat in response to LPS. The discharges of neurons in PVN had no significant change in the vagotomy rats in response to LPS.

CONCLUSIONThe results indicate that vagus nerve may be one of the pathways of peripheral LPS signal communicating to CNS.

Animals ; Diaphragm ; innervation ; Fever ; chemically induced ; physiopathology ; Lipopolysaccharides ; Male ; Neurons ; physiology ; Paraventricular Hypothalamic Nucleus ; physiopathology ; Rats ; Rats, Wistar ; Vagotomy, Truncal