Tight junctions (TJs) are the most apical intercellular junctions of epithelial cells formed by occludin, claudins, junctional adhesion molecules (JAMs), and zonula occludens (ZO). Tight junction proteins can sense the presence of bacteria and regulate the transcription of target genes that encode effectors and regulators of the immune response. The aim of this study was to determine the impact of TJ proteins in response to Porphyromonas gingivalis (P. gingivalis), P. gingivalis lipopolysaccharide (P. gingivalis LPS), and extracellular adenosine triphosphate (ATP) in the oral epithelial cell culture model. Quantified real time-polymerase chain reaction (RT-PCR), immunoblots, and immunostaining were performed to assess the gene and protein expression in TJs. It was found that P. gingivalis infection led to transient upregulation of the genes encoding occludin, claudin-1, and claudin-4 but not JAM-A, claudin-15, or ZO-1, while P. gingivalis LPS increased claudin-1, claudin-15, and ZO-1 and decreased occludin, JAM-A, and claudin-4. Tight junction proteins showed significant upregulation in the above two groups when cells were pretreated with ATP for 3 h. The findings indicated that P. gingivalis induced the host defence responses at an early stage. P. gingivalis LPS exerted a more powerful stimulatory effect on the disruption of the epithelial barrier than P. gingivalis. ATP stimulation enhanced the reaction of TJ proteins to P. gingivalis invasion and LPS destruction of the epithelium.International Journal of Oral Science (2018) 10, e8; doi:10.1038/ijos.2017.51; published online 10 January 2018.
Adenosine Triphosphate ; pharmacology ; Cells, Cultured ; Epithelial Cells ; cytology ; Gene Expression ; Humans ; Immunoblotting ; Lipopolysaccharides ; pharmacology ; Mouth Mucosa ; cytology ; Porphyromonas gingivalis ; immunology ; Real-Time Polymerase Chain Reaction ; Tight Junction Proteins ; metabolism ; Up-Regulation

BACKGROUNDSepsis is a major cause of mortality in Intensive Care Units. Anesthetic dose isoflurane and 100% oxygen were proved to be beneficial in sepsis; however, their application in septic patients is limited because long-term hyperoxia may induce oxygen toxicity and anesthetic dose isoflurane has potential adverse consequences. This study was scheduled to find the optimal combination of isoflurane and oxygen in protecting experimental sepsis and its mechanisms.

METHODSThe effects of combined therapy with isoflurane and oxygen on lung injury and sepsis were determined in animal models of sepsis induced by cecal ligation and puncture (CLP) or intraperitoneal injection of lipopolysaccharide (LPS) or zymosan. Mouse RAW264.7 cells or human peripheral blood mononuclear cells (PBMCs) were treated by LPS to probe mechanisms. The nuclear factor kappa B (NF-κB) signaling molecules were examined by Western blot and cellular immunohistochemistry.

RESULTSThe 0.5 minimum alveolar concentration (MAC) isoflurane in 60% oxygen was the best combination of oxygen and isoflurane for reducing mortality in experimental sepsis induced by CLP, intraperitoneal injection of LPS, or zymosan. The 0.5 MAC isoflurane in 60% oxygen inhibited proinflammatory cytokines in peritoneal lavage fluids (tumor necrosis factor-alpha [TNF-β]: 149.3 vs. 229.7 pg/ml, interleukin [IL]-1β: 12.5 vs. 20.6 pg/ml, IL-6: 86.1 vs. 116.1 pg/ml, and high-mobility group protein 1 [HMGB1]: 323.7 vs. 449.3 ng/ml; all P< 0.05) and serum (TNF-β: 302.7 vs. 450.7 pg/ml, IL-1β: 51.7 vs. 96.7 pg/ml, IL-6: 390.4 vs. 722.5 pg/ml, and HMGB1: 592.2 vs. 985.4 ng/ml; all P< 0.05) in septic animals. In vitro experiments showed that the 0.5 MAC isoflurane in 60% oxygen reduced inflammatory responses in mouse RAW264.7 cells, after LPS stimulation (all P< 0.05). Suppressed activation of NF-κB pathway was also observed in mouse RAW264.7 macrophages and human PBMCs after LPS stimulation or plasma from septic patients. The 0.5 MAC isoflurane in 60% oxygen also prevented the increases of phospho-IKKβ/β, phospho-IκBβ, and phospho-p65 expressions in RAW264.7 macrophages after LPS stimulation (all P< 0.05).

CONCLUSIONCombined administration of a sedative dose of isoflurane with 60% oxygen improves survival of septic animals through reducing inflammatory responses.

Adult ; Anesthesia ; methods ; Animals ; Blotting, Western ; Bronchoalveolar Lavage Fluid ; Disease Models, Animal ; Female ; Humans ; Inflammation ; drug therapy ; Isoflurane ; therapeutic use ; Leukocytes, Mononuclear ; metabolism ; Lipopolysaccharide Receptors ; metabolism ; Lipopolysaccharides ; pharmacology ; Lung Injury ; drug therapy ; immunology ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; NF-kappa B ; metabolism ; Oxygen ; therapeutic use ; Peroxidase ; metabolism ; RAW 264.7 Cells ; Rats, Sprague-Dawley ; Sepsis ; drug therapy ; immunology ; Tumor Necrosis Factor-alpha ; metabolism

Lipooligosacharide (LOS) of Neisseria gonorrhoeae (gonococci, GC) is involved in the interaction of GC with host cells. Deletion of the alpha-oligosaccharide (alpha-OS) moiety of LOS (lgtF mutant) significantly impairs invasion of GC into epithelial cell lines. GC opacity (Opa) proteins, such as OpaI, mediate phagocytosis and stimulate chemiluminescence responses in neutrophils in part through interaction with members of the carcinoembryonic antigen (CEA) family, which includes CEACAM3 (CD66d), a human neutrophil specific receptor for phagocytosis of bacteria. In the present work, we examined the effects of OpaI-expressing lgtF mutant on phagocytosis by HeLa-CEACAM3 cells and chemiluminescence responses in neutrophils. The results showed that lgtF mutant even expressing OpaI completely lost the ability to promote either phagocytosis mediated by CEACAM3 interaction in HeLa cells or chemiluminescence responses in neutrophils. These data indicated that Opa proteins in the lgtF mutant, which might result from the conformational change, cannot be functional.
Antigens, Bacterial ; chemistry ; genetics ; immunology ; metabolism ; Carbohydrate Sequence ; Carcinoembryonic Antigen ; genetics ; immunology ; Gene Expression Regulation ; HeLa Cells ; Host-Pathogen Interactions ; Humans ; Lipopolysaccharides ; chemistry ; immunology ; Luminescent Measurements ; Mutation ; Neisseria gonorrhoeae ; genetics ; metabolism ; pathogenicity ; Neutrophils ; immunology ; microbiology ; Phagocytosis

OBJECTIVEA study was conducted to investigate the effects of Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) on the expression of regulated upon activation normal T-cell expressed and secreted (RANTES) and fractalkine in human umbilical vein endothelial cells (HUVECs).

METHODSHUVECs were incubated with different concentrations of Pg-LPS (200, 500, and 1000 ng x mL(-1)) for 1, 6, 12, and 24 h, respectively. Then real time quantitative polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent method (ELISA) were adopted to detect the protein levels and mRNA levels of RANTES and fractalkine.

RESULTSThe RANTES protein levels and mRNA levels, as well as fractalkine mRNA levels, were significantly higher in all experimental groups of 1, 6, and 12 h than in the control group (P<0.05), except the expression of RANTES mRNA in 200 ng x mL(-1) group of 12 h and RANTES protein in 200 ng x mL(-1) group of 1 h. The expression levels of RANTES mRNA and fractalkine mRNA were highest in 1000 ng x mL(-1) group of 6 h and were 4.88- and 6.20-fold higher, respectively, than those in the control group. The expression levels of RANTES protein, mRNA, and fractalkine mRNA decreased 6 h after stimulation, and were significantly higher than those in the control group (P<0.05) in the RANTES and fractalkine in HUVEC, and such expression is important in the development of atherosclerosis 500 ng x mL(-1) group of 24 h. There was a significant difference between the expression of fractalkine mRNA in 1000 ng x mL(-1) group of 6 and 12 h than in the control group (P<0.05).

CONCLUSIONPg-LPS infection might up-regulate the expression of RANTES and fractalkine in HUVEC, and such expression is important in the development of atherosclerosis.

Atherosclerosis ; Cells, Cultured ; Chemokine CCL5 ; genetics ; metabolism ; Chemokine CX3CL1 ; analysis ; genetics ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Human Umbilical Vein Endothelial Cells ; metabolism ; Humans ; Lipopolysaccharides ; pharmacology ; Porphyromonas gingivalis ; immunology ; isolation & purification ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Up-Regulation

Endotoxic responses to bacterial lipopolysaccharide (LPS) are triggered by Toll-like receptor 4 (TLR4) and involve the production of inflammatory mediators, including interleukin-6 (IL-6), by macrophages. The detailed mechanism of IL-6 production by macrophages in response to LPS has remained unclear, however. We now show that LPS induces IL-6 synthesis in mouse peritoneal macrophages via the leukotriene B4 receptor BLT2. Our results suggest that TLR4-MyD88 signaling functions upstream of BLT2 and that the generation of reactive oxygen species (ROS) by NADPH oxidase 1 (Nox1) and consequent activation of the transcription factor nuclear factor (NF)-kappaB function downstream of BLT2 in this response. These results suggest that a TLR4-MyD88-BLT2-Nox1-ROS-NF-kappaB pathway contributes to the synthesis of IL-6 in LPS-stimulated mouse macrophages.
Animals ; Cell Line ; Interleukin-6/*biosynthesis ; Leukotriene B4/metabolism ; Ligands ; Lipopolysaccharides/immunology ; Macrophages/immunology/*metabolism ; Macrophages, Peritoneal/immunology/metabolism ; Mice ; Myeloid Differentiation Factor 88/*metabolism ; NADH, NADPH Oxidoreductases/metabolism ; NF-kappa B/metabolism ; Reactive Oxygen Species/metabolism ; Receptors, Leukotriene B4/*metabolism ; Signal Transduction

In the present study, we analyzed the role of Ginkgo biloba extract in lipopolysaccharide(LPS)-induced acute lung injury (ALI). ALI was induced in mice by intratracheal instillation of LPS. G. biloba extract (12 and 24 mg·kg(-1)) and dexamethasone (2 mg·kg(-1)), as a positive control, were given by i.p. injection. The cells in the bronchoalveolar lavage fluid (BALF) were counted. The degree of animal lung edema was evaluated by measuring the wet/dry weight ratio. The superoxidase dismutase (SOD) and myeloperoxidase (MPO) activities were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, tumor necrosis factor-a, interleukin-1b, and interleukin-6, were assayed by enzyme-linked immunosorbent assay. Pathological changes of lung tissues were observed by H&E staining. The levels of NF-κB p65 and COX-2 expression were detected by Western blotting. Compared to the LPS group, the treatment with the G. biloba extract at 12 and 24 mg·kg(-1) markedly attenuated the inflammatory cell numbers in the BALF, decreased NF-κB p65 and COX-2 expression, and improved SOD activity, and inhibited MPO activity. The histological changes of the lungs were also significantly improved. The results indicated that G. biloba extract has a protective effect on LPS-induced acute lung injury in mice. The protective mechanism of G. biloba extract may be partly attributed to the inhibition of NF-κB p65 and COX-2 activation.
Acute Lung Injury ; chemically induced ; drug therapy ; metabolism ; Animals ; Bronchoalveolar Lavage Fluid ; cytology ; Cell Count ; Cyclooxygenase 2 ; genetics ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Ginkgo biloba ; chemistry ; Interleukin-1beta ; analysis ; Interleukin-6 ; analysis ; Lipopolysaccharides ; Lung ; immunology ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Peroxidase ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; Pulmonary Edema ; Superoxide Dismutase ; metabolism ; Transcription Factor RelA ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; analysis

BACKGROUNDA proinflammatory milieu emerging in the lung due to neutrophil accumulation and activation is a key in the pathogenesis of acute lung injury (ALI). 15-deoxy-Δ(12, 14)-prostaglandin J2 (15d-PGJ2), one of the terminal products of the cyclooxygenase-2 pathway, is known to be the endogenous ligand of peroxisome proliferator-activated receptor γ (PPAR-γ) with multiple physiological properties. Growing evidence indicates that 15d-PGJ2 has anti-inflammatory, antiproliferative, cytoprotective and pro-resolving effects. We investigated whether 15d-PGJ2 has a protective effect against endotoxin-induced acute lung injury in rats.

METHODSTwenty-four male Wistar rats were randomly assigned into four groups (n = 6 per group): sham+vehicle group, sham+15d-PGJ2 group, LPS+vehicle group, and LPS+15d-PGJ2 group. The rats were given either lipopolysaccharide (LPS, 6 mg/kg intravenously) or saline, and pretreated with 15d-PGJ2 (0.3 mg/kg intravenously) or its vehicle (dimethyl sulphoxide) 30 minutes before LPS. Histological alterations, wet/dry weight (W/D) ratio and myeloperoxidase (MPO) activity as well as tumor necrosis factor (TNF)-α and cytokine-induced neutrophil chemoattractant-1 (CINC-1) levels were determined in lung tissues four hours after LPS injection. Immunohistochemical analysis for intercellular adhesion molecule-1 (ICAM-1) expression and Western blotting analysis for nuclear factor (NF)-κB p65 translocation and IκBα protein levels were also studied.

RESULTS15d-PGJ2 pretreatment significantly attenuated LPS-induced lung injury, and reduced the increased W/D ratio, MPO activity, TNF-α, CINC-1 levels, and ICAM-1 expression in the lung. 15d-PGJ2 also suppressed the nuclear NF-κB p65 translocation and increased cytosolic IκBα levels.

CONCLUSIONS15d-PGJ2 protects against endotoxin-induced acute lung injury, most likely through the reduction of proinflammatory protein levels during endotoxemia subsequent to the inhibition of NF-κB activation.

Acute Lung Injury ; chemically induced ; drug therapy ; immunology ; Animals ; Chemokine CXCL1 ; metabolism ; I-kappa B Proteins ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Lipopolysaccharides ; toxicity ; Male ; NF-KappaB Inhibitor alpha ; NF-kappa B ; metabolism ; Prostaglandin D2 ; analogs & derivatives ; therapeutic use ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUNDProtectin D1 (PD1), derived from docosahexaenoic acid, has been shown to control and resolve inflammation in some experimental models of inflammatory disorders. We investigated the protective roles of protectin D1 in pulmonary inflammation and lung injury induced by lipopolysaccharide (LPS).

METHODSMice were randomly assigned to six groups (n = 6 per group): sham-vehicle group, sham-PD1 group, sham-zVAD-fmk group, LPS-vehicle group, LPS-PD1 group, and LPS-PD1-zVAD-fmk group. Mice were injected intratracheally with 3 mg/kg LPS or saline, followed 24 hours later by intravenous injection of 200 µg/mouse PD1 or vehicle. At the same time, some mice were also injected intraperitoneally with the pan-caspase inhibitor zVAD-fmk. Seventy-two hours after LPS challenge, samples of pulmonary tissue and bronchoalveolar lavage fluid were collected. Optical microscopy was used to examine pathological changes in lungs. Cellularity and protein concentration in bronchoalveolar lavage fluid were analyzed. Lung wet/dry ratios and myeloperoxidase activity were measured. Apoptosis of neutrophils in bronchoalveolar lavage fluid (BALF) was also evaluated by flow cytometry.

RESULTSIntratracheal instillation of LPS increased neutrophil counts, protein concentration in bronchoalveolar lavage fluid and myeloperoxidase activity, it induced lung histological injury and edema, and also suppressed apoptosis of neutrophils in BALF. Posttreatment with PD1 inhibited LPS-evoked changes in BALF neutrophil counts and protein concentration and lung myeloperoxidase activity, with the outcome of decreased pulmonary edema and histological injury. In addition, PD1 promoted apoptosis of neutrophils in BALF. The beneficial effects of PD1 were blocked by zVAD-fmk.

CONCLUSIONPosttreatment with PD1 enhances resolution of lung inflammation during LPS-induced acute lung injury by enhancing apoptosis in emigrated neutrophils, which is, at least in part, caspase-dependent.

Acute Lung Injury ; chemically induced ; drug therapy ; immunology ; Animals ; Apoptosis ; drug effects ; Docosahexaenoic Acids ; therapeutic use ; Inflammation ; drug therapy ; Lipopolysaccharides ; toxicity ; Male ; Mice ; Mice, Inbred BALB C ; Neutrophils ; cytology ; drug effects ; Peroxidase ; metabolism

BACKGROUNDA variety of inflammatory mediators and effector cells participate together in acute lung injury, and lead to secondary injury that is due to an inflammatory cascade and secondary diffuse lung parenchyma injury. Inflammation is associated with an oxidative stress reaction, which is produced in the development of airway inflammation, and which has positive feedback on inflammation itself. Resolvin D1 can reduce the infiltration of neutrophils, regulate cytokine levels and reduce the inflammation reaction, and thereby promote the resolution of inflammation. The purpose of this study is to investigate the effects of resolvin D1 on an inflammatory response and oxidative stress during lipopolysaccharide (LPS)-induced acute lung injury.

METHODSLPS (3 mg/kg) was used to induce the acute lung injury model. Pretreatment resolvin D1 (100 ng/mouse) was given to mice 30 minutes before inducing acute lung injury. Mice were observed at 6 hours, 12 hours, 1 day, 2 days, 3 days, 4 days and 7 days after LPS was administrated, then they were humanely sacrificed. We collected bronchoalveolar lavage fluid (BALF) and the lung tissues for further analysis. Paraffin section and HE staining of the lung tissues were made for histopathology observations. Parts of the lung tissues were evaluated for wet-to-dry (W/D) weight ratio. tumor necrosis factor (TNF)-α, inter leukin (IL)-1β, IL-10 and myeloperoxidase (MPO) were detected by enzyme-linked immunosorbent assay (ELISA). A lipid peroxidation malondialdehyde (MDA) assay kit was used to detect MDA. A total superoxide dismutase assay kit with WST-1 was used to analyze superoxide dismutase (SOD). We determined the apoptosis of neutrophils by Flow Cytometry. A real-time quantitative PCR Detecting System detected the expression of mRNA for heme oxygenase (HO)-1.

RESULTSPretreatment with resolvin D1 reduced the pathological damage in the lung, decreased the recruitment of neutrophils and stimulated their apoptosis. It markedly decreased the expressions of TNF-α, IL-1β and increased the expressions of IL-10, and decreased the production of MDA and increased the expressions of SOD. The mRNA expression of HO-1 was also significantly increased.

CONCLUSIONSResolvin D1 displays potent anti-inflammatory actions by regulating cytokines, inhibiting aberrant neutrophil recruitment and stimulating apoptosis of neutrophils. Resolvin D1 can also relieve the injury due to oxidative stress. The mechanisms might be related to increase HO-1 expression.

Acute Lung Injury ; chemically induced ; drug therapy ; immunology ; Animals ; Bronchoalveolar Lavage Fluid ; immunology ; Docosahexaenoic Acids ; therapeutic use ; Interleukin-10 ; metabolism ; Interleukin-1beta ; metabolism ; Lipopolysaccharides ; toxicity ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; drug effects ; Peroxidase ; metabolism ; Superoxide Dismutase ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo discuss the effect of matrine on nitric oxide (NO) and asymmetric methylarginine (ADMA) metabolism pathways in serum and tissues of mice with lipopolysaccharide (LPS) -induced intestine tissue inflammation.

METHODKunming mice were randomly divided into five groups: the normal control group, the LPS group and matrine (80, 40, 20 mg x kg(-1) x d(-1)) groups. The mice were intragastrically administered with drugs for 3 d (distilled water of the same volume for the normal control group and the LPS group). One hour after the last intragastrical administration, normal saline or LPS (1 mg x kg(-1)) were intraperitoneally injected. Twelve hours later, serum and tissues were collected to determine NO and ADMA levels and observe the pathological changes of intestinal tissues. The Western blot method was adopted to detect the protein expressions of arginine methyltransferases 1 (PRMT1) and dimethylarginine dimethylaminohydrolase 2 (DDAH2) in intestinal tissues.

RESULTCompared with the model group, matrine (80, 40, 20 mg x kg(-1) x d(-1)) groups showed lower NO content in serum and tissues, higher ADMA level in serum and increased PRMT1 expression in intestinal tissues, but without effect on DDAH2 expression.

CONCLUSIONMatrine could inhibit LPS-induced intestine tissue inflammation in mice. Its action mechanism is related to the decreased NO content in serum and tissues and increased ADMA level in serum and PRMT1 expression in intestinal tissues.

Alkaloids ; administration & dosage ; Animals ; Arginine ; analogs & derivatives ; blood ; metabolism ; Humans ; Inflammation ; Intestinal Diseases ; drug therapy ; enzymology ; immunology ; metabolism ; Intestines ; drug effects ; enzymology ; immunology ; metabolism ; Lipopolysaccharides ; adverse effects ; Male ; Mice ; Nitric Oxide ; blood ; metabolism ; Protein-Arginine N-Methyltransferases ; genetics ; metabolism ; Quinolizines ; administration & dosage