LPS-induced NF-κB Phosphorylation Research Articles

Identification of the Role of Mume fructus in Treating Nocturnal Asthma Based on Network Pharmacology and In vitro Investigation

Abstract Objective: Mume fructus is commonly used in traditional Chinese medicine to treat nocturnal asthma symptoms. However, the molecular mechanisms underlying its effects on nocturnal asthma have not yet been established. This study evaluated the therapeutic mechanisms of Mume fructus in treating nocturnal asthma. Materials and Methods: Network pharmacology was used to investigate the chemical composition, critical targets, and potential mechanisms of action of Mume fructus in treating nocturnal asthma. “Mume fructus” and “nocturnal asthma” were used as keywords to search the relevant databases. The 16HBE and RAW264.7 cells were treated with various concentrations of Mume fructus and lipopolysaccharides (LPSs). Data provided included analyses of cell viability detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, cell proliferation and apoptosis detected by 5-ethynyl-2’-deoxyuridine and Hoechst 33342, messenger ribonucleic acid (mRNA) levels obtained by real-time polymerase chain reaction, and protein expression detected by Western blotting. Additionally, immunofluorescence was used to detect nuclear translocation. Results: Network pharmacology analyses were mainly enriched in nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK) pathway, and interleukin (IL)-6. Mume fructus and LPS had no effect on viability, proliferation, and apoptosis in 16HBE and RAW264.7 cells under certain concentration conditions. Mume fructus counteracted LPS-stimulated mRNA and protein expression of IL-6. In addition, Mume fructus treatment prevented the LPS-induced phosphorylation of NF-κB and MAPK pathways, as well as the nuclear translocation of NF-κB p-p65 in the 16HBE and RAW264.7 cells. Conclusions: Mume fructus can treat nocturnal asthma by regulating the NF-κB and MAPK pathways and counteracting IL-6 expression. These findings provide a scientific basis for the use of Mume fructus in the treatment of nocturnal asthma.

Design and Synthesis of l-1'-Homologated Adenosine Derivatives as Potential Anti-inflammatory Agents.

Inflammatory responses are fundamental protective warning mechanisms. However, in certain instances, they contribute significantly to the development of several chronic diseases such as cancer. Based on previous studies of truncated 1'-homologated adenosine derivatives, l-nucleosides and their nucleobase-modified quinolone analogues were designed, synthesized, and evaluated for anti-inflammatory activities. The target molecules were synthesized via the key intramolecular cyclization of monotosylate and Mitsunobu condensation from the natural product, d-ribose. All compounds tested and showed potent anti-inflammatory activities, as indicated by their inhibition of LPS-induced IL-1β secretion from the RAW 264.7 macrophages. Gene expressions of pro-inflammatory cytokines showed that all compounds, except 3a and 3b, significantly reduced LPS-induced IL-1β and IL-6 mRNA expressions. The half-maximal inhibitory concentrations (IC50) of 2g and 2h against IL-1β were 1.08 and 2.28 μM, respectively. In contrast, only 2d, 2g, and 3d effectively reversed LPS-induced TNFα mRNA expression. Our mechanistic study revealed that LPS-induced phosphorylation of NF-κB was significantly downregulated by all compounds tested, providing evidence that the NF-κB signaling pathway is involved in their anti-inflammatory activities. Among the compounds tested, 2g and 2h had the most potent anti-inflammatory effects, as shown by the extent of decrease in pro-inflammatory gene expression, protein secretion, and NF-κB phosphorylation. These findings suggest that the l-truncated 1'-homologated adenosine skeleton and its nucleobase-modified analogues have therapeutic potential as treatments for various human diseases by mediating inflammatory processes.

In Vitro and In Vivo Anti-Inflammatory Effects of Cannabidiol Isolated from Novel Hemp (Cannabis sativa L.) Cultivar Pink Pepper.

Cannabis sativa L. contains more than 80 cannabinoids, among which cannabidiol (CBD) is the main neuroactive component. We aimed to investigate the anti-inflammatory efficacy of CBD in vitro and in vivo isolated from "Pink pepper", a novel hemp cultivar, by repeating the method of selecting and cultivating individuals with the highest CBD content. We investigated the effects of CBD on inflammatory markers elevated by lipopolysaccharide (LPS) treatment in RAW 264.7 mouse macrophage cells through Western blot and RT-PCR. In addition, we confirmed these effects through the ELISA of inflamed paw tissue of a λ-carrageenan-induced mouse edema model that received an oral administration of CBD. CBD inhibited the LPS-induced phosphorylation of NF-κB and MAPK in RAW 264.7 and exhibited anti-inflammatory effects by participating in these pathways. In our in vivo study, we confirmed that CBD also inhibited the inflammatory mediators of proteins extracted from edematous mouse paw tissue. These results show that CBD isolated from "Pink pepper" exhibits potent anti-inflammatory effects. These anti-inflammatory effects of CBD have pharmacological and physiological significance, highlighting the industrial value of this novel cultivar.

The Anti-inflammatory Effects of Two Ent-kaurane Diterpenes from the Stems and Leaves of Gochnatia decora

The Gochnatia decora (Kurz) A. L. Cabrera is a rare woody plant belonging to the family of Asteraceae. The bark of this plant is used as a Chinese folk medicine to treat cough and pneumonia. However, the effective substance related to its efficacy remains unknown. This study aims to evaluate the potential anti-inflammatory activities of the chemicals isolated from this plant using a model of LPS-induced RAW264.7 cells. Chemical constituents were isolated from the stems and leaves of G. decora by a series of chromatographic separation methods and identified by spectral analysis techniques. The model of inflammation in vitro was established by treatment of 1μM LPS on RAW264.7 cells. The influence of tested compounds on inflammatory factor production, including NO, TNF-α, IL-1β, IL-6, IL-17, was determined by ELISA. The mechanisms involved were studied by western blot analysis. Two known ent-kaurane diterpenes (1 and 2), identified as ent-17-hydroxy-15-oxokauran- 19-oic acid (1) and ent-15α-hydroxy-16-kauran-19-oic acid (2), were isolated from the stems and leaves of G. decora. The bioassay showed that both of them produced significant inhibition of LPS-induced release of NO, TNF-α, IL-1β, IL-6, IL-17, iNOS, and COX-2 expression. Western blot analysis showed that these two chemicals blocked LPS-induced phosphorylation of NF-κB. Compounds 1 and 2 were obtained from the genus Gochnatia.These compounds demonstrated useful anti-inflammatory activities in the model of LPS-induced RAW264.7 cells. A potential action mechanism may be the correlation of the NF-κB pathway.

Atorvastatin suppresses lipopolysaccharide-induced inflammation in human coronary artery endothelial cells

The present study was designed to examine the effects of atorvastatin on vascular inflammatory responses in human coronary artery endothelial cells(HCAECs), when challenged by lipopolysaccharide (LPS), a Toll-like receptor-4 (TLR4) ligand. HCAECs were pretreated with atorvastatin and induced by LPS. The expression of TLR4, interleukin -6(IL-6), monocyte chemoattractant protein 1(MCP-1), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecular-1(ICAM-1), nuclear factor-κB (NF-κB) and p38 mitogen activated protein kinase(p38 MAPK) were evaluated using Real-time polymerase chain reaction, cytokine ELISA assay and Western blotting. The results showed that pretreatment with atorvastatin down-regulated the expression of TLR4 in LPS-activated HCAECs. Atorvastatin also attenuated the LPS-induced expression of interleukin IL-6 and MCP-1, at both the transcription and translation level in HCAECs. LPS-induced endothelial cell adhesion molecules, ICAM-1 and VCAM-1 expression were also reduced by pretreatment with atorvastatin. Furthermore, atorvastatin efficiently suppressed LPS-induced phosphorylation of NF-κB and p38 MAPK in HCAECs. These findings show that atorvastatin suppresses endothelial cell inflammation, suggesting that atorvastatin may be suitable for development as a therapeutic agent for inflammatory cardiovascular disease.

Enhanced cell selectivity of hybrid peptides with potential antimicrobial activity and immunomodulatory effect

BackgroundHybridization is a useful strategy to bond the advantages of different peptides into novel constructions. We designed a series of AMPs based on the structures of a synthetic AMP KFA3 and a naturally-occurred host defense peptide substance P (SP) to obtain peptides retaining the high antibacterial activity of KFA3 and the immunomodulatory activity and low cytotoxicity of SP. MethodsTwo repeats of KFA and different C terminal fragments of SP were hybridized, generating a series of novel AMPs (KFSP1–8). The antibacterial activities, host cell toxicity and immunomodulation were measured. The antibacterial mechanisms were investigated. ResultsHybrid peptides KFSP1–4 exerted substantial antibacterial activities against Gram-negative bacteria of standard strains and clinical drug-resistant isolates including E.coli, A.baumannii and P.aeruginosa, while showing little toxicity towards host cells. Compared with KFA3, moderate reduction in α-helix content and the interruption in α-helix continuality were indicated in CD spectra analysis and secondary-structure simulation in these peptides. Membrane permeabilization combined with time-kill studies and FITC-labeled imaging, indicated a selective membrane interaction of KFSP1 with bacteria cell membranes. By specially activating NK1 receptor, the hybrid peptides kept the ability of SP to induce intracellular calcium release and ERK1/2 phosphorylation, but unable to stimulate NF-κB phosphorylation. KFSP1 facilitated the survival of mouse macrophage RAW264.7, directly interacting with LPS and inhibiting the LPS-induced NF-κB phosphorylation and TNF-α expression. ConclusionHybridization is a useful strategy to bond the advantages of different peptides. KFSP1 and its analogs are worth of advanced efforts to explore their potential applications as novel antimicrobial agents.

028 The activation status of nuclear factor κB in type 2 conventional dendritic cells before therapy correlates with clinical response to adalimumab

Biologic therapies have revolutionised the treatment of psoriasis. Nevertheless, clinical response to therapy is unpredictable. Thus, there is a need to identify biomarkers predictive of response to enable patient stratification. Here, we investigate the effects of adalimumab (TNF-inhibitor) on the activation of nuclear factor κB (NF-κB) in the immune cells of psoriasis patients during the early phase of therapy. We hypothesize that monitoring the activation of the transcription factor downstream of the cytokine neutralized by a biologic can guide in the discovery of predictive biomarkers. Whole blood (n=16) and peripheral blood mononuclear cells (n=30) samples, obtained from psoriasis patients at baseline and weeks 1, 4 and 12 after commencing treatment, were stimulated with TNF or LPS; NF-κB nuclear translocation was quantified by imaging flow and NF-κB phosphorylation by phospho-flow cytometry. Clinical response was defined as 75% reduction in baseline psoriasis area severity index (PASI75) at week 12. TNF induced NF-κB translocation in T cells, dendritic cells (DCs), monocytes and neutrophils, while LPS, activated monocytes, DCs and neutrophils at baseline. In patients receiving adalimumab, TNF activation was significantly inhibited at each time point in T cells (92% at week 1, p<0.01), and to a lesser extent, in DCs (55% at week 1, p<0.05) compared to baseline but did not change in monocytes or neutrophils. As expected, adalimumab did not affect LPS-induced NF-κB translocation. However, we observed increased LPS-induced NF-κB translocation at baseline in the DC of patients who did not reach PASI75, as compared to patients reaching PASI75 (FDR<0.01). Importantly, this finding was replicated in an extended cohort of patients receiving adalimumab, where we detected increased LPS-induced NF-κB phosphorylation at baseline in type 2 conventional DC (cDC2) of patients not reaching PASI75 (FDR<0.001). Taken together, these data suggest that clinical response to adalimumab may depend on the baseline NF-κB activation status of cDC2.

An Algal Metabolite-Based PPAR-γ Agonist Displayed Anti-Inflammatory Effect via Inhibition of the NF-κB Pathway

In our previous study, a synthetic compound, (+)-(R,E)-6a1, that incorporated the key structures of anti-inflammatory algal metabolites and the endogenous peroxisome proliferator-activated receptor γ (PPAR-γ) ligand 15-deoxy-∆12,14-prostaglandin J2 (15d-PGJ2), exerted significant PPAR-γ transcriptional activity. Because PPAR-γ expressed in macrophages has been postulated as a negative regulator of inflammation, this study was designed to investigate the anti-inflammatory effect of the PPAR-γ agonist, (+)-(R,E)-6a1. Compound (+)-(R,E)-6a1 displayed in vitro anti-inflammatory activity in lipopolysaccharides (LPS)-stimulated murine RAW264.7 macrophages. Compound (+)-(R,E)-6a1 suppressed the expression of proinflammatory factors, such as nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), possibly by the inhibition of the nuclear factor-κB (NF-κB) pathway. In macrophages, (+)-(R,E)-6a1 suppressed LPS-induced phosphorylation of NF-κB, inhibitor of NF-κB α (IκBα), and IκB kinase (IKK). These results indicated that PPAR-γ agonist, (+)-(R,E)-6a1, exerts anti-inflammatory activity via inhibition of the NF-κB pathway.

Salsalate ameliorates the atherosclerotic response through HO-1- and SIRT1-mediated suppression of ER stress and inflammation.

Inflammation plays a causative role in atherosclerosis development. Salsalate is an anti-inflammatory drug used to treat atherosclerosis, but the mechanisms by which it affects atherosclerotic progression remain unclear. Human umbilical vascular endothelial cells (HUVECs) and THP-1 human monocytes were treated with salsalate. Heme oxygenase 1 (HO-1) and sirtuin 1 (SIRT1) small interfering RNAs (siRNAs) were used to suppress each gene expression. Protein analyses were performed for measuring the expression of HO-1, SIRT1, nuclear factor kappa B (NFκB), cell adhesion molecules, and endoplasmic reticulum (ER) stress markers. Furthermore, cell adhesion assay, caspase 3 activity assay, and ELISA were also performed. In this study, we show that salsalate increases the expression of HO-1 and SIRT1 in HUVEC and suppresses lipopolysaccharide (LPS)-induced atherosclerotic responses via HO-1- and SIRT1-mediated pathways. Salsalate treatment of HUVEC and THP-1 cells reduced LPS-induced phosphorylation of NFκB and secretion of the proinflammatory cytokines TNFα and MCP-1. Salsalate treatment of HUVEC reduced the expression of the adhesion molecules ICAM, VCAM, and E-selectin and the LPS-induced adhesion of THP-1 cells to HUVEC. Salsalate treatment also attenuated LPS-induced ER stress and cell apoptosis. These anti-atherosclerotic effects were reversed by treating cells with siRNA for HO-1 and SIRT1. Salsalate ameliorates LPS-induced atherosclerotic reactions via HO-1 and SIRT1-dependent reduction of inflammation and ER stress. Activation of these pathways by salsalate may provide therapeutic strategies for treating atherosclerosis.

MicroRNA let-7c Improves LPS-Induced Outcomes of Endometritis by Suppressing NF-κB Signaling.

Endometritis is a common inflammatory disease which endangers human and animal reproductive health. MicroRNA (miRNA) let-7c plays an important role in the inflammatory process; however, the regulatory underlying mechanism of let-7c in endometritis is unclear. In this study, we confirmed that let-7c was significantly reduced in LPS-induced mouse endometritis model, and overexpression of let-7c was able to effectively reduce uterine tissue damage caused by lipopolysaccharide (LPS), and then, a LPS-induced bovine endometrial epithelial cell (BEND) line was used to mimic the inflammatory model in vitro. Our data showed that overexpression of let-7c significantly reduced the expression of pro-inflammatory cytokines in BEND cells induced by LPS. Meanwhile, immunofluorescence and western blotting results showed that let-7c significantly inhibited LPS-induced phosphorylation of NF-κB, thereby inhibiting downstream pro-inflammatory cytokine expression. Taken together, our results suggested that let-7c ameliorates LPS-induced endometritis by attenuating the expression of pro-inflammatory cytokines via inhibition of the activation of NF-κB.

Metformin Protects against LPS-Induced Intestinal Barrier Dysfunction by Activating AMPK Pathway.

Metformin not only regulates energy metabolism but also participates in many cellular processes. In this study, we investigated the effect of metformin on lipopolysaccharide (LPS)-induced intestinal barrier damage. We found that LPS treatment decreased the expression of tight junction proteins and caused a proinflammatory response and oxidative stress in the intestine. Interestingly, metformin treatments attenuated LPS-induced intestinal barrier damage, inflammation, and oxidative stress. We found that metformin improved the expression of intestinal tight junction proteins (ZO1, occludin, and Claudin1) that were reduced by LPS stimulation. Moreover, metformin alleviated LPS-induced NF-κB phosphorylation, promoted Nrf2 nuclear translocation, and increased the expression of the antioxidative genes (HO-1 and NQO-1), leading to reduced intestinal ROS content. Mechanistically, we found that metformin protects against LPS-induced intestinal barrier dysfunction by activating AMPK. These results reveal the potential of metformin as an effective therapy for treating intestinal diseases.

Teuvincenone F Suppresses LPS-Induced Inflammation and NLRP3 Inflammasome Activation by Attenuating NEMO Ubiquitination.

Inflammation causes many diseases that are serious threats to human health. However, the molecular mechanisms underlying regulation of inflammation and inflammasome activation are not fully understood which has delayed the discovery of new anti-inflammatory drugs of urgent clinic need. Here, we found that the natural compound Teuvincenone F, which was isolated and purified from the stems and leaves of Premna szemaoensis, could significantly inhibit lipopolysaccharide (LPS)–induced pro-inflammatory cytokines production and NLRP3 inflammasome activation. Our results showed that Teuvincenone F attenuated K63-linked ubiquitination of NF-κB-essential modulator (NEMO, also known as IKKγ) to suppress LPS-induced phosphorylation of NF-κB, and inhibited mRNA expression of IL-1β, IL-6, TNF-α, and NLRP3. In addition, we found that decreased NLRP3 expression by Teuvincenone F suppressed NLRP3 inflammasome activation and IL-1β/IL-18 maturation. In vivo, we revealed that Teuvincenone F treatment relieved LPS-induced inflammation. In conclusion, Teuvincenone F is a highly effective natural compound to suppress LPS-induced inflammation by attenuating K63-linked ubiquitination of NEMO, highlighting that Teuvincenone F may be a potential new anti-inflammatory drug for the treatment of inflammatory and NLRP3 inflammasome-driven diseases.

Glycolipids from spinach suppress LPS-induced vascular inflammation through eNOS and NK-κB signaling

Glycolipids are the major constituent of the thylakoid membrane of higher plants and have a variety of biological and pharmacological activities. However, anti-inflammatory effects of glycolipids on vascular endothelial cells have not been elucidated. Here, we investigated the effect of glycolipids extracted from spinach on lipopolysaccharides (LPS)-induced endothelial inflammation and evaluated the underlying molecular mechanisms. Treatment with glycolipids from spinach had no cytotoxic effects on cultured human umbilical vein endothelial cells (HUVECs) and significantly blocked the expression of LPS-induced interleukin (IL)-6, monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), and intracellular adhesion molecule-1 (ICAM-1) in them. Glycolipids treatment also effectively suppressed monocyte adhesion to HUVECs. Treatment with glycolipids inhibited LPS-induced NF-κB phosphorylation and nuclear translocation. In addition, glycolipids treatment significantly promoted endothelial nitric oxide synthase (eNOS) activation and nitric oxide (NO) production in HUVECs. Furthermore, glycolipids treatment blocked LPS-induced inducible NOS (iNOS) expression in HUVECs. Pretreatment with a NOS inhibitor attenuated glycolipids-induced suppression of NF-κB activation and adhesion molecule expression, and abolished the glycolipids-mediated suppression of monocyte adhesion to HUVECs. These results indicate that glycolipids suppress LPS-induced vascular inflammation through attenuation of the NF-κB pathway by increasing NO production in endothelial cells. These findings suggest that glycolipids from spinach may have a potential therapeutic use for inflammatory vascular diseases.

Alpha-ketoglutarate suppresses the NF-κB-mediated inflammatory pathway and enhances the PXR-regulated detoxification pathway.

Alpha-ketoglutarate (AKG) is a critical nutritional factor in the maintenance of intestinal homeostasis. However, the relative mechanism of AKG has not been well understood. It was recently shown that the interaction between nuclear factor kappa B (NF-κB)-mediated inflammatory pathway and pregnane X receptor (PXR)-regulated detoxification pathway is a check and balance mechanism for keeping the homeostatic state of the intestine, preventing the onset of intestinal inflammation which may lead to cancer. In the current study we used lipopolysaccharide (LPS)-challenged piglet and intestinal porcine epithelial cells-J2 models to investigate the effects of dietary AKG supplementation on the intestinal immune system and PXR regulated target expression. We found that LPS induced significant activation of the NF-κB-mediated inflammatory pathway with concomitant impairment of intestinal nutrient absorption. AKG administration increased intracellular AKG and its metabolite concentrations and enhanced the mRNA expression of alpha-ketoglutarate dehydrogenase in vivo and in vitro. Thus dietary AKG supplementation reversed the adverse effects induced by LPS. We also found a strong inhibitory effects on the NF-κB-mediated inflammatory pathway, especially, in the AKG-treated intestinal tissues, LPS-induced NF-κB phosphorylation was inhibited and TNF-α was suppressed. Interestingly, AKG has potent effects in regulating the PXR and its downstream targets such as CYP3As and CYP2Bs in vivo and in vitro, although AKG is not a known PXR ligand. One potential mechanism for the up-regulation of the PXR pathway is through the down-regulation of NF-κB pathway which in turn de-represses the PXR-regulated target expression. Taken together, our results suggest that AKG improves intestinal immune system through modulating the interaction between PXR and NF-κB. Our findings have important implications for the prevention and treatment of intestinal inflammatory diseases in neonates.

Nur77 attenuates endothelin-1 expression via downregulation of NF-κB and p38 MAPK in A549 cells and in an ARDS rat model.

Acute respiratory distress syndrome (ARDS) is characterized by inflammatory injury to the alveolar and capillary barriers that results in impaired gas exchange and severe acute respiratory failure. Nuclear orphan receptor Nur77 has emerged as a regulator of gene expression in inflammation, and its role in the pathogenesis of ARDS is not clear. The objective of this study is to investigate the potential role of Nur77 and its underlying mechanism in the regulation of endothelin-1 (ET-1) expression in lipopolysaccharide (LPS)-induced A549 cells and an ARDS rat model. We demonstrate that LPS induced Nur77 expression and nuclear export in A549 cells. Overexpression of Nur77 markedly decreased basal and LPS-induced ET-1 expression in A549 cells, whereas knockdown of Nur77 increased the ET-1 expression. LPS-induced phosphorylation and nuclear translocation of NF-κB and p38 MAPK were blocked by Nur77 overexpression and augmented by Nur77 knockdown in A549 cells. In vivo, LPS induced Nur77 expression in lung in ARDS rats. Pharmacological activation of Nur77 by cytosporone B (CsnB) inhibited ET-1 expression in ARDS rats, decreased LPS-induced phosphorylation of NF-κB and p38 MAPK, and relieved lung, liver, and kidney injury. Pharmacological deactivation of Nur77 by 1,1-bis-(3′-indolyl)-1-(p-hydroxyphenyl)methane (DIM-C-pPhOH, C-DIM8) had no effect on ET-1 expression and lung injury. These results indicated that Nur77 decreases ET-1 expression by suppressing NF-κB and p38 MAPK in LPS-stimulated A549 cells in vitro, and, in an LPS-induced ARDS rat model, CsnB reduced ET-1 expression and lung injury in ARDS rats.

Regulatory effect of cytokine-induced neutrophil chemoattractant, epithelial neutrophil-activating peptide 78 and pyrrolidine dithiocarbamate on pulmonary neutrophil aggregation mediated by nuclear factor-κB in lipopolysaccharide-induced acute respiratory distress syndrome mice.

In the present study, the regulatory effect of cytokine-induced neutrophil chemoattractant (CINC) and epithelial neutrophil-activating peptide 78 (ENA-78) on pulmonary neutrophil (PMN) accumulation in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) mice, and the therapeutic effect of pyrrolidine dithiocarbamate (PDTC), was investigated. BALB/c mice were divided into control, LPS and PDTC + LPS groups using a random number table. The phosphorylation of nuclear factor-κB (NF-κB) was detected using a western blot, and the mRNA expression levels of CINC were evaluated using reverse transcription-quantitative polymerase chain reaction. The expression of NF-κB, CINC and ENA-78 was detected using immunohistochemistry. The production of interleukin (IL)-8 and IL-10 in serum and broncho-alveolar lavage fluid (BALF) was analyzed using an enzyme-linked immunosorbent assay. The total number of leukocytes and proportion of PMNs in BALF was also determined. Following injection with LPS (20 mg/kg), the expression levels of p-NF-κB, CINC and ENA-78 were increased in lung tissue, and the expression levels of IL-8, IL-10 and the number of PMNs increased in serum and BALF. However, in comparison with the LPS group, the degree of lung injury was reduced in ARDS mice that were treated with PDTC. In addition, the expression level of p-NF-κB and the production of chemokines in lung tissue decreased in ARDS mice that were treated with PDTC, and the number of PMNs in BALF also decreased. In conclusion, the results of the present study suggest that the LPS-induced phosphorylation of NF-κB may result in the synthesis and release of CINC and ENA-78, which induce the accumulation of PMNs in the lung. Therefore, PDTC may be used to reduce the production of chemokines and cytokines, thereby decreasing the activation of PMNs in lung tissue and reducing the damage of lung tissue in ARDS.

C1P Attenuates Lipopolysaccharide-Induced Acute Lung Injury by Preventing NF-κB Activation in Neutrophils.

Recently, ceramide-1-phosphate (C1P) has been shown to modulate acute inflammatory events. Acute lung injury (Arnalich et al. 2000. Infect. Immun. 68: 1942-1945) is characterized by rapid alveolar injury, lung inflammation, induced cytokine production, neutrophil accumulation, and vascular leakage leading to lung edema. The aim of this study was to investigate the role of C1P during LPS-induced acute lung injury in mice. To evaluate the effect of C1P, we used a prophylactic and therapeutic LPS-induced ALI model in C57BL/6 male mice. Our studies revealed that intrapulmonary application of C1P before (prophylactic) or 24 h after (therapeutic) LPS instillation decreased neutrophil trafficking to the lung, proinflammatory cytokine levels in bronchoalveolar lavage, and alveolar capillary leakage. Mechanistically, C1P inhibited the LPS-triggered NF-κB levels in lung tissue in vivo. In addition, ex vivo experiments revealed that C1P also attenuates LPS-induced NF-κB phosphorylation and IL-8 production in human neutrophils. These results indicate C1P playing a role in dampening LPS-induced acute lung inflammation and suggest that C1P could be a valuable candidate for treatment of ALI.

N-adamantyl-4-methylthiazol-2-amine suppresses lipopolysaccharide-induced brain inflammation by regulating NF-κB signaling in mice

We report that N-adamantyl-4-methylthiazol-2-amine (KHG26693), a novel thiazole derivative, can prevent lipopolysaccharide (LPS)-induced brain inflammation in mice. In this LPS-induced model of brain inflammation, administration of KHG26693 effectively prevented increases in the levels of IL-1β, TNF-α, prostaglandin E2, malondialdehyde, and nitric oxide, and mitigated reductions in the levels of superoxide dismutase in the hippocampus. KHG26693 also prevented reductions in the levels of hippocampal brain-derived neurotrophic factors. Furthermore, pretreatment with KHG26693 prior to LPS treatment dramatically attenuated the elevation of inducible nitric oxide synthase and cyclooxygenase-2 protein levels. Moreover, pretreatment with KHG26693 significantly suppressed LPS-induced phosphorylation of NF-κB and IκBα through the inactivation of IKKβ. Additionally, KHG26693 caused the downregulation of LPS-induced cystathionine-b-synthase gene expression in the brain. Although the clinical relevance of our findings remains to be determined, our data suggest that KHG26693 might prevent neuronal cell injury via the reduction of inflammation and oxidative stress in the brain.

Modulation of endothelial cell integrity and inflammatory activation by commercial lipid emulsions.

BackgroundThrombosis and immune dysfunction are two important complications that result from the administration of parenteral nutrition. Endothelial cells within the vasculature are crucial components necessary for maintenance of normal coagulation and immune function.MethodsWe compared the effects of three commercial lipid emulsions (LEs; Intralipid®, ClinOleic® [or Clinolipid®], and Omegaven®) differing in the levels of omega-6 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, omega-9 monounsaturated fatty acids, and saturated fatty acids upon endothelial cell fatty acid composition using Gas chromatography, endothelial cell integrity by assessing measurement of apoptosis and necrosis using flow cytometry, endothelial cell inflammatory activation by assessing the induction of ICAM-1 by lipopolysaccharide [LPS]), and transcription factor activation (phosphorylation of NF-κB) using western blot analysis.ResultsGas chromatographic analysis confirmed cellular uptake of the fatty acids within the LEs; furthermore, these fatty acid changes reflected the composition of the oils and egg phosphatides used in the manufacturing of these emulsions. However, the kinetics of fatty acid uptake and processing differed between LEs. Fish oil LE negatively impacted cell viability by doubling the percentage of apoptotic and necrotic cell populations quantified by flow cytometry using Annexin V/Fluorescein and propidium iodide. The soybean oil LE did not alter cell viability, while the olive oil-predominate emulsion improved cell viability. All LEs were capable of suppressing LPS-induced ICAM-1 expression; however, the fish oil LE was more potent than the other emulsions. Fish oil LE supplementation of cells also suppressed LPS-induced phosphorylation of NF-κB, while the soybean oil and olive predominant LE had no effect upon NF-κB phosphorylation.ConclusionsLipid emulsions are readily incorporated and stored in the form of triacylglycerols. Soybean oil-based, olive oil-predominant and fish-oil based LEs differentially affected endothelial cell integrity. Importantly, these three LEs were capable of suppressing endothelial cell inflammatory response despite their fatty acid content.

Anti-inflammatory effect of litsenolide B2 isolated from Litsea japonica fruit via suppressing NF-κB and MAPK pathways in LPS-induced RAW264.7 cells

The anti-inflammatory effects of compounds isolated from the Litsea japonica fruit were investigated in LPS-stimulated murine macrophage (RAW 264.7) cells. The results indicated that litsenolide (LN)B2 significantly inhibited the LPS-induced release of pro-inflammatory mediators, such as NO and PGE2. LNC2, and, on the other hand, exhibited cytotoxicity at the same concentrations at which it exhibited an inhibitory property. Therefore, only LNB2 was used for further experimentation. LNB2 reduced the LPS-induced production of pro-inflammatory cytokines. We further investigated the mechanism by which LNB2 inhibits pro-inflammatory mediators and cytokines by examining the level of NF-κB and MAPKs phosphorylation, which all serve as key components in inflammation-induced signaling pathways in RAW 264.7 cells. LNB2 inhibited the LPS-induced phosphorylation of NF-κB and MAPKs. These results suggest that LNB2 has an anti-inflammatory effect, inhibiting the production of pro-inflammatory mediators and cytokines via inhibition of NF-κB and MAPK signaling in LPS-stimulated RAW 264.7 cells.