Release Of Tumor Necrosis Factor Research Articles

Aripiprazole inhibits polyI:C-induced microglial activation possibly via TRPM7

Viral infections during fetal and adolescent periods, as well as during the course of schizophrenia itself have been linked to the onset and/or relapse of a psychosis. We previously reported that the unique antipsychotic aripiprazole, a partial D2 agonist, inhibits the release of tumor necrosis factor (TNF)-α from interferon-γ-activated rodent microglial cells. Polyinosinic-polycytidylic acid (polyI:C) has recently been used as a standard model of viral infections, and recent in vitro studies have shown that microglia are activated by polyI:C. Aripiprazole has been reported to ameliorate behavioral abnormalities in polyI:C-induced mice.To clarify the anti-inflammatory properties of aripiprazole, we investigated the effects of aripiprazole on polyI:C-induced microglial activation in a cellular model of murine microglial cells and possible surrogate cells for human microglia.PolyI:C treatment of murine microglial cells activated the production of TNF-α and enhanced the p38 mitogen-activated protein kinase (MAPK) pathway, whereas aripiprazole inhibited these responses. In addition, polyI:C treatment of possible surrogate cells for human microglia markedly increased TNF-α mRNA expression in cells from three healthy volunteers. Aripiprazole inhibited this increase in cells from two individuals. PolyI:C consistently increased intracellular Ca2+ concentration ([Ca2+]i) in murine microglial cells by influx of extracellular Ca2+. We demonstrated that transient receptor potential in melastatin 7 (TRPM7) channels contributed to this polyI:C-induced increase in [Ca2+]i.Taken together, these data suggest that aripiprazole may be therapeutic for schizophrenia by reducing microglial inflammatory reactions, and TRPM7 may be a novel therapeutic target for schizophrenia. Further studies are needed to validate these findings.

Nanoemulsion as a carrier to improve the topical anti-inflammatory activity of stem bark extract of Rapanea ferruginea.

The aim of this study was to develop nanoemulsion containing soft extract of stem bark of Rapanea ferruginea to improve the topical delivery and anti-inflammatory activity. The extract of R. ferruginea stem bark was incorporated into the oily phase of the nanoemulsion by the method of phase inversion at low energy. The developed nanoemulsion had an average droplet size of 47.88±8.20 nm and a polydispersibility index of 0.228. Uniformity of size, spherical shape of droplet, and absence of clusters were confirmed by transmission electronic microscopy. The zeta potential was −34.7±1.15 mV. The nanoemulsion showed a moderate degree of skin irritation in the agarose overlay assay in vitro. The content of the extract markers, myrsinoic acids A and B, was 54.10±0.08 and 53.03 μg/g in the formulation, respectively. The formulation demonstrated pseudoplastic and thixotropic rheological behavior. In vitro release of chemical markers was controlled by diffusion mechanism. An extract-loaded nanoemulsion showed a topical anti-inflammatory activity in a croton oil-induced edema ear model, with a decrease in tumor necrosis factor release and myeloperoxidase activity. The nanoemulsion was 160% more efficient than the conventional cream containing 0.13% of the extract. The nanoemulsion showed suitable properties as a carrier for topical use of R. ferruginea extract and the approach for improving the topical anti-inflammatory activity.

Dendritic Cells Are Involved in the Effects of Exercise in a Model of Asthma.

This study investigated the effects of aerobic exercise (AE) on both the maturation of dendritic cells (DC) and the activation of lymphocytes in a mouse model of chronic allergic airway inflammation. C57BL/6 mice distributed into control, exercise, ovalbumin (OVA), and OVA + exercise groups were submitted to OVA sensitization and challenge. Treadmill training was performed for 4 wk, and mice were assessed for classical features of chronic allergic airway inflammation as well as dendritic cell activation and T-lymphocyte response. AE reduced OVA-induced eosinophilic inflammation as observed in bronchoalveolar lavage fluid (P < 0.001), airway walls (P < 0001), and also reduced collagen deposition (P < 0.001). AE also reduced bronchoalveolar lavage fluid cytokines (interleukin [IL]-4, P < 0.001; IL-5, P < 0.01; IL-6, P < 0.001; IL-13, P < 0.01; and tumor necrosis factor α, P < 0.01). Cells derived from mediastinal lymphnodes of AE animals that were restimulated with OVA produced less IL-4 (P < 0.01), IL-5 (P < 0.01), and IL-13 (P < 0.001). In addition, AE reduced both DC activation, as demonstrated by reduced release of IL-6 (P < 0.001), CXCL1/KC (P < 0.01), IL-12p70 (P < 0.01), and tumor necrosis factor α (P < 0.05) and DC maturation, as demonstrated by lower MCH-II expression (P < 0.001). AE attenuated dendritic cell and lymphocyte activation and maturation, which contributed to reduced airway inflammation and remodeling in the OVA model of chronic allergic airway inflammation.

IRhom2 (Uncv) mutation blocks bulge stem cells assuming the fate of hair follicle.

iRhom2 is necessary for maturation of TNFα-converting enzyme, which is required for the release of tumor necrosis factor. In the previous study, we found that the iRhom2 (Uncv) mutation in N-terminal cytoplasmic domain-encoding region (iRhom2 (Uncv) ) leads to aberrant hair shaft and inner root sheath differentiation, thus results in a hairless phenotype in homozygous iRhom2 (Uncv/Uncv) BALB/c mice. In this study, we found iRhom2 mutation decreased hair matrix proliferation, however, iRhom2 (Uncv/Uncv) mice displayed hyperproliferation and hyperkeratosis in the interfollicular epidermis along with hypertrophy in the sebaceous glands. The number of bulge SCs was not altered and the hair follicle cycle is normal in iRhom2 (Uncv/Uncv) mice. The decreased proliferation in hair matrix but increased proliferation in epidermis and sebaceous glands in iRhom2 (Uncv/Uncv) mice may implying that iRhom2 (Uncv) mutation blocks bugle stem cells assuming the fate of hair follicle. This study identifies iRhom2 as a novel regulator for determination of keratinocyte lineages.

Aqueous and Ethanol Extracts of Australian Cane Toad Skins Suppress Pro‐Inflammatory Cytokine Secretion in U937 Cells via NF‐κB Signaling Pathway

Toad skin extracts, such as aqueous extracts (AE) of Chinese toad skins, have demonstrated therapeutic benefits for a range of diseases including pain, inflammation, swelling, heart failure, and various types of cancers. In this study, we investigated the anti-inflammatory potential of an AE (0.1-10 μg/mL) and a 60% ethanol extract (EE; 0.1-10 μg/mL) from Australian cane toad (Bufo marinus) skins and the known bioactive compound, bufotenine (BT; 0.1-10 nM). The assay employed a model of the human monocyte cell line U937 stimulated with lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) for the release of tumor necrosis factor (TNF)-α and interleukin (IL)-6. We demonstrated that AE, EE, and BT significantly inhibited the release and expression of TNF-α and IL-6 in a dose-dependent manner when the cells were pre-treated at non-cytotoxic concentrations. Further investigation revealed that the inhibition of TNF-α and IL-6 release and expression was associated with the suppression of nuclear factor (NF)-kappa (κ)B activation. These results indicate that AE, EE, and BT are strong inflammation inhibitors, thus have the potential for further development as anti-inflammatory therapeutic agents from a natural source regarded as a feral pest in Australia. J. Cell. Biochem. 117: 2769-2780, 2016. © 2016 Wiley Periodicals, Inc.

Optineurin suppression activates the mediators involved in the terminal effector pathways of human labour and delivery

Spontaneous preterm birth remains the major cause of neonatal death and morbidity. Studies in non-gestational tissues report that optineurin (OPTN) is critical in the termination of NFKB1 activity and control of inflammation, central features of spontaneous preterm birth. The aims of the present study were to determine: (1) OPTN expression in fetal membranes and the myometrium during labour; (2) the effects of IL1B on OPTN expression in primary myometrial cells; and (3) the effects of OPTN short interference (si) RNA on IL1B-stimulated proinflammatory and prolabour mediators. OPTN mRNA and protein expression was significantly decreased with spontaneous term labour in fetal membranes and the myometrium. Although there was no effect of spontaneous preterm labour on OPTN expression in fetal membranes, there was decreased OPTN expression in membranes with chorioamnionitis and myometrial cells treated with 1ng mL-1 IL1B for 1 or 6h. In cells transfected with OPTN siRNA, significant increases were seen in IL1B-stimulated IL6, tumour necrosis factor, CXCL8 and monocyte chemoattractant protein-1 mRNA expression and release, cyclo-oxygenase-2 and prostanoid PTGFR receptor mRNA expression and the release of prostaglandin F2α. There was no change in IL1B-stimulated NFKBIA expression; however, there was increased NFKB1 p65 DNA-binding activity. The results of the present study suggest that OPTN is a negative regulator of inflammation-induced prolabour mediators.

Plasma Mitochondrial DNA--a Novel DAMP in Pediatric Sepsis.

Mitochondrial DNA (mtDNA) is a novel danger-associated molecular pattern that on its release into the extracellular milieu acts via toll-like receptor-9, a pattern recognition receptor of the immune system. We hypothesized that plasma mtDNA concentrations will be elevated in septic children, and these elevations are associated with an increase in the severity of illness. In a separate set of in vitro experiments, we test the hypothesis that exposing peripheral blood mononuclear cells (PBMC) to mtDNA activates the immune response and induces tumor necrosis factor (TNF) release. Children with sepsis/systemic inflammatory response syndrome or control groups were enrolled within 24 h of admission to the pediatric intensive care unit. Mitochondrial gene cytochrome c oxidase 1 (COX1) concentrations were measured by real-time quantitative PCR in the DNA extracted from plasma. PBMCs were treated with mtDNA (10 μg/mL) and supernatant TNF levels were measured. The median plasma mtDNA concentrations were significantly elevated in the septic patients as compared with the critically ill non-septic and healthy control patients [1.75E+05 (IQR 6.64E+04-3.67E+05) versus 5.73E+03 (IQR 3.90E+03-1.28E+04) and 6.64E+03 (IQR 5.22E+03-1.63E+04) copies/μL respectively]. The median concentrations of plasma mtDNA were significantly greater in patients with MOF as compared with patients without MOF (3.2E+05 (IQR 1.41E+05-1.08E+06) vs. 2.9E+04 (IQR 2.47E+04-5.43E+04) copies/μL). PBMCs treated with mtDNA demonstrated higher supernatant TNF levels as compared with control cells (6.5 ± 1.8 vs. 3.5 ± 0.5 pg/mL, P > 0.05). Our data suggest that plasma mtDNA is a novel danger-associated molecular pattern in pediatric sepsis and appears to be associated with MOF.

Effects of Geum urbanum L. root extracts and its constituents on polymorphonuclear leucocytes functions. Significance in periodontal diseases

Ethnopharmacological relevanceGeum urbanum L. (wood avens) root infusions and decoctions have been used externally for reducing the bleeding and inflammation of gums (gingivitis), and mucous membranes. Aim of the studyTaking into account that primed and hyperactivated neutrophils are an important factor in the transition from gingivitis to periodontitis, we investigated the effects of phytochemically characterised (HPLC-DAD-MSn) extracts of different polarity from Geum urbanum root on oxidative burst, elastase, metalloproteinase 9 (MMP-9), interleukin 8 (IL-8) and 1β (IL-1β), tumour necrosis factor (TNF-α) release, expression of adhesion molecules (CD62L and CD11b) and delayed apoptosis in stimulated neutrophils. As gemin A is a dominating compound in a raw material, so we considered its activity in parallel with the positive control quercetin. Materials and methodsThe extracts were characterised by HPLC-DAD- MSn method. The inhibition of ROS production by stimulated neutrophils was determined using luminol dependent chemiluminescence method. The effect on MMP-9, IL-1β, TNF-α and IL-8 production by neutrophils was measured by enzyme-linked immunosorbent assay (ELISA). Neutrophil elastase release was established spectrophotometrically. The expression of adhesion molecules and the apoptosis of neutrophils was analyzed with flow cytometry. ResultsThe main compounds detected in the extract belong mainly to the group of ellagitannin: pedunculagin, stachyurin, casuarynin and gemin A, and ellagic acid derivatives. Procyanidins and one complex tannin were found as minor compounds. Gemin A significantly affected the functions of stimulated neutrophils by reducing the surface expression of CD11b, and inhibiting the release of reactive oxygen species, and proteases (elastase, MMP-9), chemokines and cytokines (interleukins IL-8, IL-1β). Interestingly, gemin A stimulated the release of TNF-α, which may be one of the stimulators of apoptosis of neutrophil cells. The primary aqueous extract, the ethyl acetate and the butanolic fractions, all containing the highest level of gemin A, have exerted similar but weaker activity. ConclusionThe modulating effect on the neutrophils function of extracts, and its main constituent gemin A, support the traditional use of this plant material in cavity inflammation including mucositis, gingivitis and periodontosis.

Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major.

ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1) immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS), form neutrophil extracellular traps (NETs) and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF) and interleukin-1beta (IL-1β) release; otherwise, transforming growth factor-beta (TGF-β) production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be considered an appropriate molecular template for the construction of an efficient anti-infective agent.

Collagen-chitosan 3-D nano-scaffolds effects on macrophage phagocytosis and pro-inflammatory cytokine release

Macrophages are effector cells in the innate and adaptive immune systems and in situ exist within three-dimensional (3-D) microenvironments. As there has been an increase in interest in the use of 3-D scaffolds to mimic natural microenvironments in vitro, this study examined the impact on cultured mice peritoneal macrophages using standard 2-D plates as compared to 3-D collagen-chitosan scaffolds. Here, 2-D and 3-D cultured macrophages were evaluated for responses to lipopolysaccharide (LPS), dexamethasone (Dex), BSA (bovine serum albumin), safranal (herbal component isolated from safranal [Saf]) and Alyssum homolocarpum mucilage (A. muc: mixed herbal components). After treatments, cultured macrophages were evaluated for viability, phagocytic activity and release of tumor necrosis factor (TNF)-α and interleukin (IL)-1β pro-inflammatory cytokines. Comparison of 2-D vs 3-D cultures showed that use of either system – with or without any exogenous agent – had no effect on cell viability. In the case of cell function, macrophages cultured on scaffolds had increases in phagocytic activity relative to that by cells on 2-D plates. In general, the test herbal components Saf and A. muc. had more impact than any of the other exogenous agents on nanoparticle uptake. With respect to production of TNFα and IL-1β, compared to the 2-D cells, scaffold cells tended to have significantly different levels of production of each cytokine, with the effect varying (higher or lower) depending on the test agent used. However, unlike with particle uptake, here, while Saf and A. muc. led to significantly greater levels of cytokine formation by the 3-D culture cells vs that by the 2-D plate cells, there was no net effect (stimulatory) vs control cultures. These results illustrated that collagen-chitosan scaffolds could provide a suitable 3-D microenvironment for macrophage phagocytosis and could also impact on the formation of pro-inflammatory cytokines.

Recruitment of CD16+ monocytes to endothelial cells in response to LPS-treatment and concomitant TNF release is regulated by CX3CR1 and interfered by soluble fractalkine

Fractalkine (FKN, CX3CL1) is a regulator of leukocyte recruitment and adhesion, and controls leukocyte migration on endothelial cells (ECs). We show that FKN triggers different effects in CD16+ and CD16− monocytes, the two major subsets of human monocytes. In the presence of ECs a lipopolysaccharide (LPS)-stimulus led to a significant increase in tumor necrosis factor (TNF)-secretion by CD16+ monocytes, which depends on the interaction of CX3CR1 expressed on CD16+ monocytes with endothelial FKN. Soluble FKN that was efficiently shed from the surface of LPS-activated ECs in response to binding of CD16+ monocytes to ECs, diminished monocyte adhesion in down-regulating CX3CR1 expression on the surface of CD16+ monocytes resulting in decreased TNF-secretion. In this process the TNF-converting enzyme (TACE) acts as a central player regulating FKN-shedding and TNFα-release through CD16+ monocytes interacting with ECs. Thus, the release and local accumulation of sFKN represents a mechanism that limits the inflammatory potential of CD16+ monocytes by impairing their interaction with ECs during the initial phase of an immune response to LPS. This regulatory process represents a potential target for therapeutic approaches to modulate the inflammatory response to bacterial components.

Antituberculosis Activity of a Naturally Occurring Flavonoid, Isorhamnetin.

Isorhamnetin (1) is a naturally occurring flavonoid having anticancer and anti-inflammatory properties. The present study demonstrated that 1 had antimycobacterial effects on Mycobacterium tuberculosis H37Rv, multi-drug- and extensively drug-resistant clinical isolates with minimum inhibitory concentrations of 158 and 316 μM, respectively. Mycobacteria mainly affect the lungs, causing an intense local inflammatory response that is critical to the pathogenesis of tuberculosis. We investigated the effects of 1 on interferon (IFN)-γ-stimulated human lung fibroblast MRC-5 cells. Isorhamnetin suppressed the release of tumor necrosis factor (TNF)-α and interleukin (IL)-12. A nontoxic dose of 1 reduced mRNA expression of TNF-α, IL-1β, IL-6, IL-12, and matrix metalloproteinase-1 in IFN-γ-stimulated cells. Isorhamnetin inhibited IFN-γ-mediated stimulation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase and showed high-affinity binding to these kinases (binding constants: 4.46 × 10(6) M(-1) and 7.6 × 10(6) M(-1), respectively). The 4'-hydroxy group and the 3'-methoxy group of the B-ring and the 5-hydroxy group of the A-ring of 1 play key roles in these binding interactions. A mouse in vivo study of lipopolysaccharide-induced lung inflammation revealed that a nontoxic dose of 1 reduced the levels of IL-1β, IL-6, IL-12, and INF-γ in lung tissue. These data provide the first evidence that 1 could be developed as a potent antituberculosis drug.

Histopathophysiology of Gout

Despite being a frequent cause of arthritis and bone erosions, the underlying cellular and subcellular reaction in gout is insufficiently understood. The inflammasome as intracellular sensor for crystals plays an important role, notably resulting in interleukin (IL)-1 production. Morphologically, hyperplasia of the synovial membrane with joint effusion, along with fibrinogen deposition and influx of neutrophils and lymphocytes are observed. Extracellular NET formation by neutrophils is involved in the regulation of inflammatory tissue reaction. Furthermore, the release of IL-10 and tumor necrosis factor (TNF)-receptors along with lymphocyte proliferation induce the natural resolution of acute gouty arthritis which typically occurs after several days. In contrast to acute gout, tophi consisting of urate crystals are surrounded by histiocytes and multinucleated cells, resembling a foreign body reaction. The deposition of extracellular matrix by fibrocytes is usually observed around tophi. This fibrotic reaction is likely enhanced by Th2-lymphocytes. Bone erosions in gout occur around tophi and are triggered by osteoclast activation through RANK-ligand expression by lymphocytes. In conclusion, understanding the orchestration of inflammation in gout might help to identify new therapeutic targets.

Interaction of mitochondrial formylated peptides with formyl peptide receptor 1 in the pathogenesis of acute lung injury

BackgroundMortality in acute respiratory distress syndrome remains high with no effective pharmacological therapies. The syndrome is characterised by dysregulated neutrophilic inflammation and tissue damage, which leads to the release of various factors including mitochondrial formylated peptides to drive neutrophil migration to sites of inflammation. This study investigated the importance of mitochondrial formylated peptides and their interaction with formyl peptide receptor 1 (FPR1) in the pathogenesis of acute lung injury. MethodsFormylated peptides were identified in bronchoalveolar lavage fluid (BALF) from patients with acute respiratory distress syndrome and healthy controls by liquid chromatography-tandem mass spectrometry. Intratracheal hydrochloric acid (pH 2) was instilled in wild-type (WT) and FPR1–/– mice, and BALF neutrophils, cytokines, and protein were quantified at 24 h. WT mice received the FPR1 antagonist cyclosporin 12 h after injury. In-vitro experiments used neutrophils from healthy human blood to assess neutrophil responses to formylated peptides. Data were analysed by t testing and ANOVA. The study was approved by Lothian Research Ethics Committee. FindingsFormylated peptides were present in patients with acute respiratory distress syndrome (n=11) but were undetectable in healthy controls (n=10). FPR1–/– mice (n=8) had reduced concentration of BALF neutrophils compared with WT mice (n=10) (49 per μL BALF [SD 48] vs 160 [93], p=0·02), less cytokine release (tumour necrosis factor α 146 pg/mL [46] vs 242 [94], p=0·03), and less protein leak (IgM 282 ng/mL [190] vs 678 [616], p=0·04). Cyclosporin H similarly reduced lung inflammation. After identification of FPR1 on type 1 alveolar epithelial cells, bone marrow chimeras confirmed that both myeloid and non-myeloid cell FPR1 contributed to alveolar protein leak during lung injury. In-vitro studies revealed that mitochondrial formylated peptides induced neutrophil responses through intracellular MAPK/PI3K signalling and upregulation of β2-integrin heterodimer macrophage-1 antigen. InterpretationThis study demonstrated that mitochondrial formylated peptides are present in acute respiratory distress syndrome and that FPR1 inhibition, or absence, reduces lung injury through neutrophil-dependent and neutrophil-independent means. Although our study combined samples from patients with those of a clinically relevant model, we used only one method of inducing lung injury, unlike that seen in acute respiratory distress syndrome. Importantly, however, FPR1 antagonists delivered after injury reduced lung inflammation suggesting a potential therapeutic role. FundingWellcome Trust, Medical Research Council.

A novel eremophilane lactone inhibits FcεRI-dependent release of pro-inflammatory mediators: structure-dependent bioactivity.

Allergic inflammation is primarily mediated by immune effector cells such as mast cells and basophils that release proinflammatory cytokines. Both mast cells and basophils are activated via their high affinity IgE receptor (FcεRI) which initiates the release of proinflammatory mediators such as histamine and tumor necrosis factor (TNF). Considerable effort has been focused on finding an effective basophil stabilizer that inhibits the activation of FcεRI-activated mediator release. Recently, eremophilane lactones, a novel family of sesquiterpene compound originally isolated from Petasites japonicas (Sieb. et Zucc.), have been described, and it has been postulated that they may have anti-inflammatory activity, particularly in allergic disease. Our objective was to determine the effect of two eremophilane lactones derived from 6β-angeloyloxy-3β,8-dihydroxyeremophil-7(11)-en-12,8β-olide (F-1) on immunoglobulin E (IgE)-dependent release of pro-inflammatory mediators by a basophil cell line, RBL-2H3, a model system for FcεRI-mediated activation of pro-inflammatory mediator release. The parent compound (F-1) was chemically modified to produce F-1a [6β-angeloyloxy-3β-benzoyloxy-8-hydroxyeremophil-7(11)-en-12,8β-olide] and F-1b [6β-angeloyloxy-3β,8-diacetoxyeremophil-7(11)-en-12,8β-olide]. RBL-2H3 cells were sensitized with DNP-specific IgE and then activated with DNP-BSA. The effect of these compounds on IgE-dependent basophil degranulation was assessed by measuring the release of β-hexosaminidase (b-hex). In addition, TNF release was measured via ELISA. The phenylacetyl reaction modified C-8 and produced F-1a whereas acetylation of F-1 produced F-1b. F-1a was not cytotoxic to RBL-2H3 cells even at 50 μM, but F-1b was slightly cytotoxic at 50 μM, reducing viability of the cells by approximately 15 %. Neither F-1a nor F-1b inhibited FcεRI-dependent activation of RBL-2H3 cells when the cells were pretreated for only 30 min with the compounds. However, 24 h pretreatment with F-1a inhibited antigen-dependent degranulation by as much as 60 % and TNF production by as much as 90 %. F-1b had no effect on RBL-2H3 activation via FcεRI. These results indicate that F-1a inhibits degranulation of RBL-2H3 cells activated via the high affinity IgE receptor, FcεRI, and that this effect is dependent upon hydroxylation of the third carbon.

Neuropeptides CRH, SP, HK-1, and Inflammatory Cytokines IL-6 and TNF Are Increased in Serum of Patients with Fibromyalgia Syndrome, Implicating Mast Cells.

Fibromyalgia syndrome (FMS) is a chronic, idiopathic condition of widespread musculoskeletal pain affecting more women than men. Even though clinical studies have provided evidence of altered central pain pathways, the lack of definitive pathogenesis or reliable objective markers has hampered development of effective treatments. Here we report that the neuropeptides corticotropin-releasing hormone (CRH), substance P (SP), and SP-structurally-related hemokinin-1 (HK-1) were significantly (P = 0.026, P < 0.0001, and P = 0.002, respectively) elevated (0.82 ± 0.57 ng/ml, 0.39 ± 0.18 ng/ml, and 7.98 ± 3.12 ng/ml, respectively) in the serum of patients with FMS compared with healthy controls (0.49 ± 0.26 ng/ml, 0.12 ± 0.1 ng/ml, and 5.71 ± 1.08 ng/ml, respectively). Moreover, SP and HK-1 levels were positively correlated (Pearson r = 0.45, P = 0.002) in FMS. The serum concentrations of the inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF) were also significantly (P = 0.029 and P = 0.006, respectively) higher (2.97 ± 2.35 pg/ml and 0.92 ± 0.31 pg/ml, respectively) in the FMS group compared with healthy subjects (1.79 ± 0.62 pg/ml and 0.69 ± 0.16 pg/ml, respectively). In contrast, serum IL-31 and IL-33 levels were significantly lower (P = 0.0001 and P = 0.044, respectively) in the FMS patients (849.5 ± 1005 pg/ml and 923.2 ± 1284 pg/ml, respectively) in comparison with healthy controls (1281 ± 806.4 pg/ml and 3149 ± 4073 pg/ml, respectively). FMS serum levels of neurotensin were not different from controls. We had previously shown that CRH and SP stimulate IL-6 and TNF release from mast cells (MCs). Our current results indicate that neuropeptides could stimulate MCs to secrete inflammatory cytokines that contribute importantly to the symptoms of FMS. Treatment directed at preventing the secretion or antagonizing these elevated neuroimmune markers, both centrally and peripherally, may prove to be useful in the management of FMS.

Quetiapine Inhibits Microglial Activation by Neutralizing Abnormal STIM1-Mediated Intercellular Calcium Homeostasis and Promotes Myelin Repair in a Cuprizone-Induced Mouse Model of Demyelination.

Microglial activation has been considered as a crucial process in the pathogenesis of neuroinflammation and psychiatric disorders. Several antipsychotic drugs (APDs) have been shown to display inhibitory effects on microglial activation in vitro, possibly through the suppression of elevated intracellular calcium (Ca2+) concentration. However, the exact underlying mechanisms still remain elusive. In this study, we aimed to investigate the inhibitory effects of quetiapine (Que), an atypical APD, on microglial activation. We utilized a chronic cuprizone (CPZ)-induced demyelination mouse model to determine the direct effect of Que on microglial activation. Our results showed that treatment with Que significantly reduced recruitment and activation of microglia/macrophage in the lesion of corpus callosum and promoted remyelination after CPZ withdrawal. Our in vitro studies also confirmed the direct effect of Que on lipopolysaccharide (LPS)-induced activation of microglial N9 cells, whereby Que significantly inhibited the release of nitric oxide (NO) and tumor necrosis factor α (TNF-α). Moreover, we demonstrated that pretreatment with Que, neutralized the up-regulation of STIM1 induced by LPS and declined both LPS and thapsigargin (Tg)-induced store-operated Ca2+ entry (SOCE). Finally, we found that pretreatment with Que significantly reduced the translocation of nuclear factor kappa B (NF-κB) p65 subunit from cytoplasm to nuclei in LPS-activated primary microglial cells. Overall, our data suggested that Que may inhibit microglial activation by neutralization of the LPS-induced abnormal STIM1-mediated intercellular calcium homeostasis.

Pathophysiology of cardiovascular dysfunction in sepsis

### Key points Sepsis is a common condition with a high mortality, which can also lead to severe sepsis and shock. This review will look at the physiological disruption of the cardiovascular system and the reflexes which occur during sepsis. The host response to sepsis is controlled by inflammatory mediators, which transmit, amplify, and maintain the generation of the host response. A specific myocardial-depressant factor has been suggested for some time, but the concept of a single agent underestimates the complexity of the immune system in sepsis.1 ### Toll-like receptors These are intermediate signalling molecules, which respond to the inflammatory stimulus and lead to the release of tumour necrosis factor α (TNF-α). These receptors impair myocyte function in vitro . ### Cytokines The major pro-inflammatory mediators in sepsis are TNF-α, interleukin (IL) 1β, IL-6, and IL-8. They are secreted from macrophages and monocytes and are responsible for amplification of the septic cascade and have been demonstrated to cause fever, hypotension, and myocardial suppression. ### Nitric oxide Nitric oxide (NO) is secreted from the endothelium and is central to cardiovascular control in health. During sepsis, NO production is increased after activation of the endothelium by pro-inflammatory mediators, resulting in up-regulation of the enzyme inducible NO synthetase (iNOS). This inducible (pathological) NO is responsible for vasodilatation. It is also responsible for dysfunction of enzyme messenger systems associated with normal intracellular calcium homeostasis and the maintenance of reflexes. ### Oxidative stress Oxidative stress is a term …

The Dietary Flavonoid Rhamnetin Inhibits Both Inflammation and Excitotoxicity During Ethanol Withdrawal in Rat Organotypic Hippocampal Slice Cultures.

Ethanol (EtOH) causes neurotoxicity via several mechanisms including neuroinflammation (during EtOH exposure), and excitotoxicity (during EtOH withdrawal [EWD]). Alpha7 nicotinic acetylcholine receptor (nAChR) selective agonists have the potential to reduce both. The aim of this study was to evaluate the anti-inflammatory and neuroprotective potential of rhamnetin, a dietary flavonoid with alpha7 nAChR selective activity, in an invitro model of EtOH-induced neurotoxicity. The anti-inflammatory and neuroprotective properties of rhamnetin were assessed in neonatal organotypic hippocampal slice cultures undergoing EWD (or not) and challenged with N-methyl-D-aspartate (NMDA) and/or lipopolysaccharide (LPS). Neurotoxicity was determined using propidium iodide uptake, and the inflammatory response was evaluated by measuring the release of tumor necrosis factor (TNF)-alpha (NO; quantified by ELISA) and nitric oxide (quantified by the Griess reaction) into culture media. As predicted, rhamnetin reduced LPS-induced release of TNF-alpha and NO both under control conditions and during EWD. Additionally, rhamnetin had no effect on NMDA-induced neurotoxicity under control conditions, but significantly reduced NMDA toxicity during EWD. In contrast, rhamnetin had no effect on neurotoxicity induced by NMDA and LPS combined despite reducing TNF-alpha and NO levels under these conditions. Rhamnetin is anti-inflammatory and neuroprotective during EWD and therefore has potential value in treating neurotoxicity caused by EtOH.

Stress-dependent control of cytokine production in mast cells stimulated through FceRI and Toll-like 4 receptors

Mast cells (MC) play an important role on allergic reactions triggered by the IgE/Antigen-dependent crosslinking of the high affinity IgE receptor (FceRI), and their participation on inflammatory innate immune responses triggered by Toll-like receptors (TLRs) has started to be documented. Physiological conditions such as stress exert a modulatory effect on allergic reactions since stress mediators activate signaling cascades that either interfere or potentiate the FceRI-dependent cytokine production. Recently, the effect of stress mediators on cytokine production induced after Toll-like receptors (TLRs) has started to be addressed in this cell type. In a recent paper, we analyzed the effects of stress induced by forced swimming (FS) on the MC-dependent production of Tumor Necrosis Factor (TNF) induced by a single intraperitoneal injection of bacterial lipopolysaccharide (LPS) in mice. FS provoked an immediate and transient inhibition of LPS-elicited TNF accumulation in peritoneum, which lasted around to 30 min. With the aim to identify the mediator of stress responsible for the inhibition, we first blocked catecholamine release from adrenal glands (by adrenalectomy) or nerve terminals (with DSP4 treatment). With these manipulations we observed an important increase on basal ip TNF levels and enhanced LPS-induced TNF release without any effect on stress-induced inhibitory effects. We then pre-treated animals with the glucocorticoid receptor antagonist mifepristone and did not observe any change on basal levels or stress-induced inhibition of TNF release. Finally, we administered an antagonist of acetylcholine receptors (mecamylamine) and observed an increase on basal levels of ip TNF values together with an important blockage of stress effects. Those results show for the first time that early MC-derived TNF secretion after Toll-like receptors is negatively controlled by adrenaline and transiently inhibited by the anti-inflammatory cholinergic reflex. Our results adds to the description of stress effects on MC activation and open new avenues in the research on the control of chronic inflammatory reactions associated with long term MC-dependent cytokine secretion.