Anti-inflammatory lipid mediators and insights into the resolution of inflammation

Amelioration of inflammatory responses by Socheongryong-Tang, a traditional herbal medicine, in RAW 264.7 cells and rats

Socheongryong-Tang (SCRT) is a natural medicine prescription that has been mainly used in East Asia for the treatment of inflammatory disorders, including asthma and allergic rhinitis. The present study evaluated the anti-inflammatory effects of SCRT on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and in a rat model of carrageenan (CA)-induced paw edema. Levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and prostaglandin E2 (PGE2) in the culture supernatant were quantified and nitric oxide (NO) production was monitored. In addition, the effect of SCRT on the protein expression of nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was assessed by western blot analysis. Furthermore, the effects of SCRT on acute inflammation in vivo and changes in the histomorphometry and histopathology of paw skin were observed using CA-treated rats. SCRT (1 mg/ml) inhibited the LPS-induced changes in the protein expression of NF-κB, JNK, ERK1/2, iNOS and COX-2, as well as the production of NO, PGE2 and cytokines. In the rat paw edema assay, administration of 1 g/kg of lyophilized powder obtained from the aqueous extracts of SCRT for 3 consecutive days inhibited the CA-induced increases in skin thickness, mast cell degranulation, and infiltration of inflammatory cells in the ventral and dorsal pedis skin within 4 h. These results demonstrated that SCRT exerts its anti-inflammatory activities in LPS-stimulated RAW 264.7 cells through decreasing the production of inflammatory mediators, including PGE2, NO and cytokines, via suppression of the NF-κB and JNK and ERK1/2 signaling pathways. In addition, the data of the CA-induced paw edema indicated an anti-edema effect of SCRT. SCRT (1 g/kg) reduced acute edematous inflammation through inhibition of mast cell degranulation and infiltration of inflammatory cells. Therefore, the present study provided scientific evidence for the anti-inflammatory activities of SCRT as well as the underlying mechanisms.

Associations of the plasma lipidome with mortality in the acute respiratory distress syndrome: a longitudinal cohort study

Background

It is unknown if the plasma lipidome is a useful tool for improving our understanding of the acute respiratory distress syndrome (ARDS). Therefore, we measured the plasma lipidome of individuals with ARDS at two time-points to determine if changes in the plasma lipidome distinguished survivors from non-survivors. We hypothesized that both the absolute concentration and change in concentration over time of plasma lipids are associated with 28-day mortality in this population.

Methods

Samples for this longitudinal observational cohort study were collected at multiple tertiary-care academic medical centers as part of a previous multicenter clinical trial. A mass spectrometry shot-gun lipidomic assay was used to quantify the lipidome in plasma samples from 30 individuals. Samples from two different days were analyzed for each subject. After removing lipids with a coefficient of variation > 30%, differences between cohorts were identified using repeated measures analysis of variance. The false discovery rate was used to adjust for multiple comparisons. Relationships between significant compounds were explored using hierarchical clustering of the Pearson correlation coefficients and the magnitude of these relationships was described using receiver operating characteristic curves.

Results

The mass spectrometry assay reliably measured 359 lipids. After adjusting for multiple comparisons, 90 compounds differed between survivors and non-survivors. Survivors had higher levels for each of these lipids except for five membrane lipids. Glycerolipids, particularly those containing polyunsaturated fatty acid side-chains, represented many of the lipids with higher concentrations in survivors. The change in lipid concentration over time did not differ between survivors and non-survivors.

Conclusions

The concentration of multiple plasma lipids is associated with mortality in this group of critically ill patients with ARDS. Absolute lipid levels provided more information than the change in concentration over time. These findings support future research aimed at integrating lipidomics into critical care medicine.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0758-3) contains supplementary material, which is available to authorized users.

Anti-inflammatory steroidal glycosides from the berries of Solanum nigrum L. (European black nightshade)

Seven previously undescribed steroidal glycosides, along with three known congeners were isolated from the unripe berries of Solanum nigrum L. (Solanaceae). Their structures were elucidated on basis of 1D and 2D NMR, HR-ESI-MS spectroscopic data and GC analysis after acid hydrolysis. The potential inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide in RAW 264.7 cell line and the anti-proliferative activities against five cancer cell lines (HL-60, U-937, Jurkat, K562 and HepG2) were evaluated. Seven compounds exhibited inhibition activities on NO production with IC₅₀ values ranging from 11.33 to 49.35 μM. Structure-activity relationships of the isolated compounds were also discussed.

4-Acetylantroquinonol B inhibits lipopolysaccharide-induced cytokine release and alleviates sepsis through of MAPK and NFκB suppression

Background

Antrodia cinnamomea is an indigenous medicinal mushroom in Taiwan, commonly used for the treatment of cancers and inflammatory disorders. 4-acetylantroquinonol B (4AAQB) is one of the active component isolated from the mycelium of A. cinnamomea. However, whether 4AAQB exhibits anti-inflammatory effect is not clear.

Methods

The anti-inflammatory activity of 4AAQB was examined by ELISA to measure the pro-inflammatory cytokines production in lipopolysaccharide (LPS)-simulated RAW264.7 cells, peritoneal macrophages and in mice. The effect of 4AAQB for MAPK kinase molecules phosphorylation in LPS-stimulated RAW264.7 macrophage including ERK, JNK and p38 were evaluated. The in vivo efficacy of 4AAQB was also demonstrated.

Results

In the present study, we found that 4AAQB exhibits anti-inflammatory effects inhibit tumor necrosis factor-α (TNF-α)/interleukin-6 (IL-6) releasing and LPS-stimulated phagocytes migration without affect cell growth. In addition, the MAPK kinase molecules phosphorylation in LPS-stimulated RAW264.7 macrophage including ERK, JNK and p38 was inhibited by 4AAQB. The phosphorylation of NFκB subunit p65 and IkBα were also decreased after 4AAQB treatment. Furthermore, 4AAQB attenuates the cytokine production in LPS-induced and CLP-induced septic mice.

Conclusion

These results showed that 4AAQB exhibited anti-inflammatory property both in vitro and in vivo, suggesting that 4AAQB may be a therapeutic candidate which used in inflammatory disorders treatment.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2172-2) contains supplementary material, which is available to authorized users.

Cathepsin B-Mediated Activation of Trypsinogen in Endocytosing Macrophages Increases Severity of Pancreatitis in Mice

BACKGROUND & AIMS

Acute pancreatitis is characterized by premature intracellular activation of digestive proteases within pancreatic acini and a consecutive systemic inflammatory response. We investigated how these processes interact during severe pancreatitis in mice.

METHODS

Pancreatitis was induced in C57Bl/6 wild-type (control), cathepsin B (CTSB)-knockout, and cathepsin L-knockout mice by partial pancreatic duct ligation with supramaximal caerulein injection, or by repetitive supramaximal caerulein injections alone. Immune cells that infiltrated the pancreas were characterized by immunofluorescence detection of Ly6g, CD206, and CD68. Macrophages were isolated from bone marrow and incubated with bovine trypsinogen or isolated acinar cells; the macrophages were then transferred into pancreatitis control or cathepsin-knockout mice. Activities of proteases and nuclear factor (NF)-κB were determined using fluorogenic substrates and trypsin activity was blocked by nafamostat. Cytokine levels were measured using a cytometric bead array. We performed immunohistochemical analyses to detect trypsinogen, CD206, and CD68 in human chronic pancreatitis (n = 13) and acute necrotizing pancreatitis (n = 15) specimens.

RESULTS

Macrophages were the predominant immune cell population that migrated into the pancreas during induction of pancreatitis in control mice. CD68-positive macrophages were found to phagocytose acinar cell components, including zymogen-containing vesicles, in pancreata from mice with pancreatitis, as well as human necrotic pancreatic tissues. Trypsinogen became activated in macrophages cultured with purified trypsinogen or co-cultured with pancreatic acini and in pancreata of mice with pancreatitis; trypsinogen activation required macrophage endocytosis and expression and activity of CTSB, and was sensitive to pH. Activation of trypsinogen in macrophages resulted in translocation of NF-kB and production of inflammatory cytokines; mice without trypsinogen activation (CTSB-knockout mice) in macrophages developed less severe pancreatitis compared with control mice. Transfer of macrophage from control mice to CTSB-knockout mice increased the severity of pancreatitis. Inhibition of trypsin activity in macrophages prevented translocation of NF-κB and production of inflammatory cytokines.

CONCLUSIONS

Studying pancreatitis in mice, we found activation of digestive proteases to occur not only in acinar cells but also in macrophages that infiltrate pancreatic tissue. Activation of the proteases in macrophage occurs during endocytosis of zymogen-containing vesicles, and depends on pH and CTSB. This process involves macrophage activation via NF-κB-translocation, and contributes to systemic inflammation and severity of pancreatitis.

Clearance of Apoptotic Cells by Tissue Epithelia: A Putative Role for Hepatocytes in Liver Efferocytosis

Toxic substances and microbial or food-derived antigens continuously challenge the liver, which is tasked with their safe neutralization. This vital organ is also important for the removal of apoptotic immune cells during inflammation and has been previously described as a “graveyard” for dying lymphocytes. The clearance of apoptotic and necrotic cells is known as efferocytosis and is a critical liver function to maintain tissue homeostasis. Much of the research into this form of immunological control has focused on Kupffer cells, the liver-resident macrophages. However, hepatocytes (and other liver resident cells) are competent efferocytes and comprise 80% of the liver mass. Little is known regarding the mechanisms of apoptotic and necrotic cell capture by epithelia, which lack key receptors that mediate phagocytosis in macrophages. Herein, we discuss recent developments that increased our understanding of efferocytosis in tissues, with a special focus on the liver parenchyma. We discuss the impact of efferocytosis in health and in inflammation, highlighting the role of phagocytic epithelia.

Clitoria ternatea flower petals: Effect on TNFR1 neutralization via downregulation of synovial matrix metalloproteases

ETHNOPHARMACOLOGICAL RELEVANCE

Clitoria ternatea Linn. (C. ternatea) is a traditionally used herb in arthritis, and its anti-arthritic activity has been attributed to polyphenols (e.g. quercetins) from its flower petal.

AIM OF THE STUDY

The present study was designed to investigate whether C. ternatea or quercetin-3ß-D-glucoside (QG) support the antibody mediated TNFα-receptor 1 (TNFR1) neutralization to ameliorate arthritis in mice.

MATERIALS AND METHODS

Development of collagen-induced arthritis (CIA) in male Swiss mice (20-22g, 3-4 weeks of age) was followed by estimation of synovial polymorphonuclear cell (PMN) accumulation (in terms of myeloperoxidase activity), synovial and systemic release of cytokines, chemokines and C-reactive protein (CRP) by enzyme-linked immunosorbent assay (ELISA), biochemical estimation of synovial free radical generation and antioxidant status, as well as immunoblot assessment of synovial TNFR1, toll-like receptor 2(TLR2), cyclooxygenase-2(COX-2) and inducible nitric oxide synthase (iNOS) expression; and zymographic analysis of synovial matrix-metalloprotease-2 (MMP-2) activity.

RESULTS

CIA was induced from day 2 post-secondary immunizations as evidenced from arthritic scores and joint swelling in parallel to increased inflammatory and oxidative stress parameters in synovial joints. Long term supplementation with extract from Clitoria ternatea flower petals CTE (50mg/kg) and QG (2.5mg/kg) upto 24 days post booster immunization augmented anti-arthritic potential of TNFR1 neutralization with anti-TNFR1 antibody (10μg per mice) in terms of reduced MPO activity, decrease in release of pro-inflammatory cytokines, chemokines, reactive oxygen species (ROS)/ reactive nitrogen species (RNS) production in parallel to significant (p<0.05) reduction in TNFR1, TLR2, iNOS, COX-2 and MMP-2 expression.

CONCLUSION

CTE and QG possess potential anti-arthritic activity which targets synovial MMP-2 in arthritic joints and TNFR1 targeting followed by CTE or QG treatment might become a combinatorial approach in future therapeutic research in treatment of arthritis.

Anti-inflammatory sesquiterpenoids from the Traditional Chinese Medicine Salvia plebeia: Regulates pro-inflammatory mediators through inhibition of NF-κB and Erk1/2 signaling pathways in LPS-induced Raw264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia plebeia R. Brown, a traditional Chinese medicinal herb, has been used to treat inflammatory diseases such as cough, hepatitis, and diarrhea for a long history.

AIM OF THE STUDY

The aim of the present study was to isolate and identify potential anti-inflammatory agents from the herb of S. plebeia, which may have contributed to its folk pharmacological use in the treatment of inflammatory diseases.

MATERIAL AND METHODS

The aerial parts of S. plebeia were extracted with 95% ethanol and separated by silica gel, RP-C₁₈, Sephadex LH-20, and HPLC. The structures of the isolated compounds were elucidated by extensive spectroscopic analysis (MS, NMR, and X-ray). Anti-inflammatory activities of all compounds were evaluated by the model of LPS-induced up-regulated of NO in Raw264.7 macrophages. The expression levels of cytokine (TNF-α) and proteins (iNOS and COX-2) were assessed by ELISA kit and Western blotting analysis, respectively. Furthermore, the influences of salviplenoid A (1) on NF-κB and MAPK signaling pathways were determined by Western blotting analysis and immunofluorescence assay.

RESULTS

Six new (1-6, salviplenoids A-F) and ten known (7-16) sesquiterpenoids were isolated from the herb of S. plebeia. The absolute configurations of compounds 1, 2, and 7 were determined by X-ray diffraction. The new eudesmane-type sesquiterpenoid, salviplenoid A (1), significantly decreased the release of NO and TNF-α and the expression of proteins iNOS and COX-2. In addition, the biochemical mechanistic study indicated that 1 regulated the NF-κB dependent transcriptional activity through inhibiting the nuclear translocation of p50/p65 dimer and decreasing the phosphorylation of IκB and Erk1/2.

CONCLUSIONS

Among all sesquiterpenoids isolated from S. plebeian, the new salviplenoid A (1) exhibited the most potent anti-inflammatory activity in LPS-induced Raw264.7 cells via inhibition of NF-κB and Erk1/2 signaling pathways.

Function of Pro-Resolving Lipid Mediator Resolvin E1 in Type 2 Diabetes

Programming of inflammation resolution is governed by a class of specialized pro-resolving lipid mediators (SPMs) that act in concert to modulate epithelial, endothelial, and immune cell function for restoration of homeostasis. The resolution circuits are altered in obesity and associated morbidities, including type 2 diabetes mellitus (T2D), through reduced production and/or action of SPMs, which can be rescued by therapeutic SPM delivery or up-regulation of SPM receptors. Resolvin E1 (RvE1), an eicosapentaenoic acid derivative, has potent pro-resolving and insulin-sensitizing actions mediated by BLT1 and ERV1 receptors in the vasculature and metabolic organs. Nonetheless, the RvE1-mediated increase in protective adipokines such as adiponectin in white adipose tissues, the enhancement of monocyte patrolling function in the vasculature, as well as the macrophage-clearing functions improve metabolic control in obese-prone conditions. RvE1-enhanced resolving function in obesity prevents dysbiosis of the gut microflora and increased gut permeability. These functions suggest that RE1 has therapeutic potential for immunometabolic alterations associated with T2D in patients with reduced inflammation resolving capacity. SPM profiling in individuals at risk for T2D and associated complications will help to advance personalized disease management and precision medicine.

Lipid (per) oxidation in mitochondria: an emerging target in the ageing process?

Lipids are essential for physiological processes such as maintaining membrane integrity, providing a source of energy and acting as signalling molecules to control processes including cell proliferation, metabolism, inflammation and apoptosis. Disruption of lipid homeostasis can promote pathological changes that contribute towards biological ageing and age-related diseases. Several age-related diseases have been associated with altered lipid metabolism and an elevation in highly damaging lipid peroxidation products; the latter has been ascribed, at least in part, to mitochondrial dysfunction and elevated ROS formation. In addition, senescent cells, which are known to contribute significantly to age-related pathologies, are also associated with impaired mitochondrial function and changes in lipid metabolism. Therapeutic targeting of dysfunctional mitochondrial and pathological lipid metabolism is an emerging strategy for alleviating their negative impact during ageing and the progression to age-related diseases. Such therapies could include the use of drugs that prevent mitochondrial uncoupling, inhibit inflammatory lipid synthesis, modulate lipid transport or storage, reduce mitochondrial oxidative stress and eliminate senescent cells from tissues. In this review, we provide an overview of lipid structure and function, with emphasis on mitochondrial lipids and their potential for therapeutic targeting during ageing and age-related disease.

Anti-Inflammatory and Antinociceptive Effects of Ethyl Acetate Fraction of an Edible Red Macroalgae Sarcodia ceylanica

Research so far has only shown that edible red macroalgae, Sarcodia ceylanica has the ability to eliminate free radicals and anti-diabetic, anti-bacterial properties. This study was conducted both in vitro and in vivo on the ethyl acetate extract (PD1) of farmed red macroalgae in order to explore its anti-inflammatory properties. In order to study the in vitro anti-inflammatory effects of PD1, we used lipopolysaccharide (LPS) to induce inflammatory responses in murine macrophages. For evaluating the potential in vivo anti-inflammatory and antinociceptive effects of PD1, we used carrageenan-induced rat paw edema to produce inflammatory pain. The in vitro results indicated that PD1 inhibited the LPS-induced pro-inflammatory protein, inducible nitric oxide synthase (iNOS) in macrophages. Oral PD1 can reduce carrageenan-induced paw edema and inflammatory nociception. PD1 can significantly inhibit carrageenan-induced leukocyte infiltration, as well as the protein expression of inflammatory mediators (iNOS, interleukin-1β, and myeloperoxidase) in inflammatory tissue. The above results indicated that PD1 has great potential to be turned into a functional food or used in the development of new anti-inflammatory and antinociceptive agents. The results from this study are expected to help scientists in the continued development of Sarcodia ceylanica for other biomedical applications.

Anti-inflammatory activity of electron-deficient organometallics

We report an evaluation of the cytotoxicity of a series of electron-deficient (16-electron) half-sandwich precious metal complexes of ruthenium, osmium and iridium ([Os/Ru(η⁶-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)] (1/2), [Ir(η⁵-pentamethylcyclopentadiene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)] (3), [Os/Ru(η⁶-p-cymene)(benzene-1,2-dithiolato)] (4/5) and [Ir(η⁵-pentamethylcyclopentadiene)(benzene-1,2-dithiolato)] (6)) towards RAW 264.7 murine macrophages and MRC-5 fibroblast cells. Complexes 3 and 6 were found to be non-cytotoxic. The anti-inflammatory activity of 1-6 was evaluated in both cell lines after nitric oxide (NO) production and inflammation response induced by bacterial endotoxin lipopolysaccharide (LPS) as the stimulus. All metal complexes were shown to exhibit dose-dependent inhibitory effects on LPS-induced NO production on both cell lines. Remarkably, the two iridium complexes 3 and 6 trigger a full anti-inflammatory response against LPS-induced NO production, which opens up new avenues for the development of non-cytotoxic anti-inflammatory drug candidates with distinct structures and solution chemistry from that of organic drugs, and as such with potential novel mechanisms of action.

Nasunin inhibits the lipopolysaccharide-induced pro-inflammatory mediator production in RAW264 mouse macrophages by suppressing ROS-mediated activation of PI3 K/Akt/NF-κB and p38 signaling pathways

Nasunin is a major anthocyanin in eggplant peel. The purpose of this study was to examine the anti-inflammatory effects of nasunin in lipopolysaccharide (LPS)-stimulated RAW264 macrophages and to identify the molecular mechanisms underlying these effects. We found that nasunin reduced the LPS-induced secretion of tumor necrosis factor-α, interleukin-6 and nitric oxide, and expression of inducible nitric oxide synthase in a dose-dependent manner. Nasunin diminished LPS-induced nuclear factor-κB (NF-κB) activation by suppressing the degradation of inhibitor of κB-α and nuclear translocation of p65 subunit of NF-κB. Nasunin also attenuated the phosphorylation of Akt and p38, signaling molecules involved in pro-inflammatory mediator production. Moreover, nasunin inhibited the intracellular accumulation of ROS, leading to the suppression of NF-κB activation, Akt and p38 phosphorylation, and subsequent pro-inflammatory mediator production. These findings suggest that nasunin exerts an anti-inflammatory effect and this effect is mediated, at least in part, by its antioxidant activity.

The oxylipin and endocannabidome responses in acute phase Plasmodium falciparum malaria in children

BACKGROUND

Oxylipins and endocannabinoids are low molecular weight bioactive lipids that are crucial for initiation and resolution of inflammation during microbial infections. Metabolic complications in malaria are recognized contributors to severe and fatal malaria, but the impact of malaria infection on the production of small lipid derived signalling molecules is unknown. Knowledge of immunoregulatory patterns of these molecules in malaria is of great value for better understanding of the disease and improvement of treatment regimes, since the action of these classes of molecules is directly connected to the inflammatory response of the organism.

METHODS

Detection of oxylipins and endocannabinoids from plasma samples from forty children with uncomplicated and severe malaria as well as twenty controls was done after solid phase extraction followed by chromatography mass spectrometry analysis. The stable isotope dilution method was used for compound quantification. Data analysis was done with multivariate (principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA®) and univariate approaches (receiver operating characteristic (ROC) curves, t tests, correlation analysis).

RESULTS

Forty different oxylipin and thirteen endocannabinoid metabolites were detected in the studied samples, with one oxylipin (thromboxane B2, TXB2) in significantly lower levels and four endocannabinoids (OEA, PEA, DEA and EPEA) at significantly higher levels in infected individuals as compared to controls according to t test analysis with Bonferroni correction. Three oxylipins (13-HODE, 9-HODE and 13-oxo-ODE) were higher in severe compared to uncomplicated malaria cases according to the results from multivariate analysis. Observed changes in oxylipin levels can be connected to activation of cytochrome P450 (CYP) and 5-lipoxygenase (5-LOX) metabolic pathways in malaria infected individuals compared to controls, and related to increased levels of all linoleic acid oxylipins in severe patients compared to uncomplicated ones. The endocannabinoids were extremely responsive to malaria infection with majority of this class of molecules found at higher levels in infected individuals compared to controls.

CONCLUSIONS

It was possible to detect oxylipin and endocannabinoid molecules that can be potential biomarkers for differentiation between malaria infected individuals and controls and between different classes of malaria. Metabolic pathways that could be targeted towards an adjunctive therapy in the treatment of malaria were also pinpointed.

Targeting Inflammation to Improve Tumor Drug Delivery

Inefficient delivery of drugs is a main cause of chemotherapy failure in hypoperfused tumors. To enhance perfusion and drug delivery in these tumors, two strategies have been developed: vascular normalization, aiming at normalizing tumor vasculature and blood vessel leakiness, and stress alleviation, aiming at decompressing tumor vessels. Vascular normalization is based on anti-angiogenic drugs, whereas stress alleviation is based on stroma-depleting agents. We present here an alternative approach to normalize tumor vasculature, taking into account that malignant tumors tend to develop at sites of chronic inflammation. Similarly to tumor vessel leakiness, inflammation is also characterized by vascular hyperpermeability. Therefore, testing the ability of anti-inflammatory agents, such as non-steroidal anti-inflammatory drugs (NSAIDs) or inflammation resolution mediators, as an alternative means to increase tumor drug delivery might prove promising.

Comparison of Anti-Inflammatory Effects of Flavonoid-Rich Common and Tartary Buckwheat Sprout Extracts in Lipopolysaccharide-Stimulated RAW 264.7 and Peritoneal Macrophages

Buckwheat sprouts have been widely consumed all around world due to their great abundance of bioactive compounds. In this study, the anti-inflammatory effects of flavonoid-rich common buckwheat sprout (CBS) and tartary buckwheat sprout (TBS) extracts were evaluated in lipopolysaccharide- (LPS-) stimulated RAW 264.7 murine macrophages and primary peritoneal macrophages from male BALB/c mice. Based on the reversed-phase HPLC analysis, the major flavonoids in CBS were determined to be C-glycosylflavones (orientin, isoorientin, vitexin, and isovitexin), quercetin-3-O-robinobioside, and rutin, whereas TBS contained only high amounts of rutin. The TBS extract exhibited higher inhibitory activity as assessed by the production of proinflammatory mediators such as nitric oxide and cytokines including tumor necrosis factor-α, interleukin- (IL-) 6, and IL-12 in LPS-stimulated RAW 264.7 macrophages than CBS extract. In addition, TBS extract suppressed nuclear factor-kappa B activation by preventing inhibitor kappa B-alpha degradation and mitogen-activated protein kinase phosphorylation in LPS-stimulated RAW 264.7 macrophages. Moreover, the TBS extract markedly reduced LPS-induced cytokine production in peritoneal macrophages. Taken together, these findings suggest that TBS extract can be a potential source of anti-inflammatory agents that may influence macrophage-mediated inflammatory disorders.

The natural phosphoinositide derivative glycerophosphoinositol inhibits the lipopolysaccharide-induced inflammatory and thrombotic responses

Inflammatory responses are elicited through lipid products of phospholipase A2 activity that acts on the membrane phospholipids, including the phosphoinositides, to form the proinflammatory arachidonic acid and, in parallel, the glycerophosphoinositols. Here, we investigate the role of the glycerophosphoinositol in the inflammatory response. We show that it is part of a negative feedback loop that limits proinflammatory and prothrombotic responses in human monocytes stimulated with lipopolysaccharide. This inhibition is exerted both on the signaling cascade initiated by the lipopolysaccharide with the glycerophosphoinositol-dependent decrease in IκB kinase α/β, p38, JNK, and Erk1/2 kinase phosphorylation and at the nuclear level with decreased NF-κB translocation and binding to inflammatory gene promoters. In a model of endotoxemia in the mouse, treatment with glycerophosphoinositol reduced TNF-α synthesis, which supports the concept that glycerophosphoinositol inhibits the de novo synthesis of proinflammatory and prothrombotic compounds and might thus have a role as an endogenous mediator in the resolution of inflammation. As indicated, this effect of glycerophosphoinositol can also be exploited in the treatment of manifestations of severe inflammation by exogenous administration of the compound.

Design, synthesis and biological evaluation of hesperetin derivatives as potent anti-inflammatory agent

A flavonoid hesperetin is reported to have a variety of biological activities, including anticancer, antiviral, antioxidant, neuroprotective and anti-inflammatory properties. Thirty-one novel hesperetin derivatives were designed, synthesized and evaluated for anti-inflammatory activity using RAW264.7 cells and CCl4-induced acute liver injury model. Among these compounds, 5b displayed the excellent anti-inflammatory activity on decreasing NO, IL-6 and TNF-α both in vitro and vivo. In addition, 5b could also reduce the release of NO, IL-6 and TNF-α production by LPS stimulated RAW 264.7 cell through MAPK and NF-κB signaling pathway in a concentration dependent manner. From in vivo study, it was also observed that 5b attenuated liver histopathologic changes in mouse models.

Patchoulene Epoxide Isolated from Patchouli Oil Suppresses Acute Inflammation through Inhibition of NF-κB and Downregulation of COX-2/iNOS

According to the GC-MS analysis, compositional variation was observed between samples of patchouli oil, of which an unknown compound identified as patchoulene epoxide (PAO) was found only in the long-stored oil, whose biological activity still remains unknown. Therefore, the present study aimed to evaluate the potential anti-inflammatory activity with three in vivo inflammatory models: xylene-induced ear edema, acetic acid-induced vascular permeability, and carrageenan-induced paw edema. Further investigation into its underlying mechanism on carrageenan-induced paw edema was conducted. Results demonstrated that PAO significantly inhibited the ear edema induced by xylene, lowered vascular permeability induced by acetic acid and decreased the paw edema induced by carrageenan. Moreover, PAO markedly decreased levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandin E2 (PGE₂), and nitric oxide (NO), but increased levels of interleukin-4 (IL-4) and interleukin-10 (IL-10). PAO was also shown to significantly downregulate the protein and mRNA expressions of cyclooxygenase-2 (COX-2) and inducible nitric-oxide synthase (iNOS). Western blot analysis revealed that PAO remarkably inhibited p50 and p65 translocation from the cytosol to the nucleus by suppressing IKKβ and IκBα phosphorylation. In conclusion, PAO exhibited potent anti-inflammatory activity probably by suppressing the activation of iNOS, COX-2 and NF-κB signaling pathways.

Evasion of immunosurveillance by genomic alterations of PPARγ/RXRα in bladder cancer

Muscle-invasive bladder cancer (MIBC) is an aggressive disease with limited therapeutic options. Although immunotherapies are approved for MIBC, the majority of patients fail to respond, suggesting existence of complementary immune evasion mechanisms. Here, we report that the PPARγ/RXRα pathway constitutes a tumor-intrinsic mechanism underlying immune evasion in MIBC. Recurrent mutations in RXRα at serine 427 (S427F/Y), through conformational activation of the PPARγ/RXRα heterodimer, and focal amplification/overexpression of PPARγ converge to modulate PPARγ/RXRα-dependent transcription programs. Immune cell-infiltration is controlled by activated PPARγ/RXRα that inhibits expression/secretion of inflammatory cytokines. Clinical data sets and an in vivo tumor model indicate that PPARγ^High/RXRα^S427F/Y impairs CD8⁺ T-cell infiltration and confers partial resistance to immunotherapies. Knockdown of PPARγ or RXRα and pharmacological inhibition of PPARγ significantly increase cytokine expression suggesting therapeutic approaches to reviving immunosurveillance and sensitivity to immunotherapies. Our study reveals a class of tumor cell-intrinsic "immuno-oncogenes" that modulate the immune microenvironment of cancer.Muscle-invasive bladder cancer (MIBC) is a potentially lethal disease. Here the authors characterize diverse genetic alterations in MIBC that convergently lead to constitutive activation of PPARgamma/RXRalpha and result in immunosurveillance escape by inhibiting CD8+ T-cell recruitment.

Integrative functional analyses using rainbow trout selected for tolerance to plant diets reveal nutrigenomic signatures for soy utilization without the concurrence of enteritis

Finding suitable alternative protein sources for diets of carnivorous fish species remains a major concern for sustainable aquaculture. Through genetic selection, we created a strain of rainbow trout that outperforms parental lines in utilizing an all-plant protein diet and does not develop enteritis in the distal intestine, as is typical with salmonids on long-term plant protein-based feeds. By incorporating this strain into functional analyses, we set out to determine which genes are critical to plant protein utilization in the absence of gut inflammation. After a 12-week feeding trial with our selected strain and a control trout strain fed either a fishmeal-based diet or an all-plant protein diet, high-throughput RNA sequencing was completed on both liver and muscle tissues. Differential gene expression analyses, weighted correlation network analyses and further functional characterization were performed. A strain-by-diet design revealed differential expression ranging from a few dozen to over one thousand genes among the various comparisons and tissues. Major gene ontology groups identified between comparisons included those encompassing central, intermediary and foreign molecule metabolism, associated biosynthetic pathways as well as immunity. A systems approach indicated that genes involved in purine metabolism were highly perturbed. Systems analysis among the tissues tested further suggests the interplay between selection for growth, dietary utilization and protein tolerance may also have implications for nonspecific immunity. By combining data from differential gene expression and co-expression networks using selected trout, along with ontology and pathway analyses, a set of 63 candidate genes for plant diet tolerance was found. Risk loci in human inflammatory bowel diseases were also found in our datasets, indicating rainbow trout selected for plant-diet tolerance may have added utility as a potential biomedical model.

IL-4 up-regulates cyclooxygenase-1 expression in macrophages

Macrophages use various cell-surface receptors to sense their environment and undergo polarized responses. The cytokines, interleukin (IL)-4 and IL-13, released from T-helper type 2 (Th2) cells, drive macrophage polarization toward an alternatively activated phenotype (M2). This phenotype is associated with the expression of potent pro-resolving mediators, such as the prostaglandin (PG) D₂-derived cyclopentenone metabolite, 15d-PGJ₂, produced by the cyclooxygenase (Ptgs; Cox) pathway. Interestingly, IL-4 treatment of bone marrow-derived macrophages (BMDMs) significantly down-regulates Cox-2 protein expression, whereas Cox-1 levels are significantly increased. This phenomenon not only challenges the dogma that Cox-1 is only developmentally regulated, but also demonstrates a novel mechanism in which IL-4-dependent regulation of Cox-1 involves the activation of the mechanistic target of rapamycin complex (mTORC). Using specific chemical inhibitors, we demonstrate here that IL-4-dependent Cox-1 up-regulation occurs at the post-transcriptional level via the Fes-Akt-mTORC axis. Activation of AMP-activated protein kinase (AMPK) by metformin, inhibition of mTORC by torin 1, or CRISPR/Cas9-mediated genetic knock-out of tuberous sclerosis complex-2 (Tsc2) blocked the IL-4-dependent expression of Cox-1 and the ability of macrophages to polarize to M2. However, use of 15d-PGJ₂ partially rescued the effects of AMPK activation, suggesting the importance of Cox-1 in macrophage polarization as also observed in a model of gastrointestinal helminth clearance. In summary, these findings suggest a new paradigm where IL-4-dependent up-regulation of Cox-1 expression may play a key role in tissue homeostasis and wound healing during Th2-mediated immune responses, such as parasitic infections.

Myeloid Cells in Cutaneous Wound Repair

Cutaneous wound repair is a complex, dynamic process with the goal of rapidly sealing any breach in the skin's protective barrier. Myeloid cells compose a significant proportion of the inflammatory cells recruited to a wound site and play important roles in decontaminating the injured tissue of any invading microorganisms. Subsequently, myeloid cells are able to influence many aspects of the healing response, in part through their capacity to release a large array of signaling molecules that allow them to communicate with and regulate the behavior of other wound cells and in turn, be themselves exquisitely regulated by the wound microenvironment. Macrophages, for example, appear to play important, temporally changing roles in the initiation of scarring and subsequently in matrix remodeling to resolve fibrosis. In this way, myeloid cells seem to play both positive (e.g., pathogen killing and matrix remodeling) and negative (e.g., scarring) roles in wound repair. Further research is of course needed to elucidate the precise temporal and spatial myeloid cell phenotypes and behaviors and ultimately to design effective strategies to optimize the beneficial functions of these cells while minimizing their detrimental contributions to improve wound healing in the clinic.

Targeted lipidomics reveals activation of resolution pathways in knee osteoarthritis in humans

OBJECTIVE

To investigate the presence of inflammation and resolution pathways in osteoarthritis (OA).

DESIGN

Tissues were obtained from knee OA patients and control rheumatoid arthritis (RA) patients. Cells in synovial fluid (SF) were visualized by flow cytometry. Cytokines and chemokines were measured by multiplex assay. Lipid mediators (LMs) were determined by targeted lipidomics using liquid-chromatography mass spectrometry.

RESULTS

SF of OA patients contained less cells, especially neutrophils, less cytokines and comparable levels of chemokines compared to RA controls. Thirty-seven lipids were detected in the soluble fraction of SF, including polyunsaturated fatty acids (PUFAs) and their pro-inflammatory and pro-resolving lipoxygenase (LOX) and cyclooxygenase (COX) pathway markers in both OA and RA patients. Among these, pro-inflammatory LM such as prostaglandin E₂ (PGE₂) and thromboxane B₂, as well as precursors and pathway markers of resolution such as 17-HDHA and 18-HEPE were detected. Interestingly, the pro-resolving lipid RvD2 could also be detected, but only in the insoluble fraction (cells and undigested matrix). Ratios of metabolites to their precursors indicated a lower activity of 5-LOX and 15-LOX in OA compared to RA, with no apparent differences in COX-derived products. Interestingly, synovial tissue and SF cells could produce 5-LOX and 15-LOX metabolites, indicating these cells as possible source of LM.

CONCLUSIONS

By using a state-of-the-art technique, we show for the first time that resolution pathways are present in OA patients. A better understanding of these pathways could guide us to more effective therapeutic approaches to inhibit inflammation and further structural damage in OA and RA.

GM-CSF- and M-CSF-primed macrophages present similar resolving but distinct inflammatory lipid mediator signatures

M1 and M2 activated macrophages (Mϕs) have different roles in inflammation. Because pathogens may first encounter resting cells, we investigated lipid mediator profiles prior to full activation. Human monocytes were differentiated with granulocyte Mϕ colony-stimulating factor (GM-CSF) or Mϕ colony-stimulating factor (M-CSF), which are known to prime toward M1 or M2 phenotypes, respectively. Lipid mediators released during resting conditions and produced in response to bacterial stimuli (LPS/N-formylmethionyl-leucyl-phenylalanine or peptidoglycan) were quantified by liquid chromatography-mass spectrometry. In resting conditions, both Mϕ phenotypes released primarily proresolving lipid mediators (prostaglandin E₂ metabolite, lipoxin A₄, and 18-hydroxyeicosapentaenoic acid). A striking shift toward proinflammatory eicosanoids was observed when the same cells were exposed (30 min) to bacterial stimuli: M-CSF Mϕs produced considerably more 5-lipoxygenase products, particularly leukotriene C₄, potentially linked to M2 functions in asthma. Prostaglandins were formed by both Mϕ types. In the M-CSF cells, there was also an enhanced release of arachidonic acid and activation of cytosolic phospholipase A₂ However, GM-CSF cells expressed higher levels of 5-lipoxygenase and 5-lipoxygenase-activating protein, and in ionophore incubations these cells also produced the highest levels of 5-hydroxyeicosatetraenoic acid. In summary, GM-CSF and M-CSF Mϕs displayed similar proresolving lipid mediator formation in resting conditions but shifted toward different proinflammatory eicosanoids upon bacterial stimuli. This demonstrates that preference for specific eicosanoid pathways is primed by CSFs before full M1/M2 activation.-Lukic, A., Larssen, P., Fauland, A., Samuelsson, B., Wheelock, C. E., Gabrielsson, S., Radmark, O. GM-CSF- and M-CSF-primed macrophages present similar resolving but distinct inflammatory lipid mediator signatures.

Bergapten prevents lipopolysaccharide-induced inflammation in RAW264.7 cells through suppressing JAK/STAT activation and ROS production and increases the survival rate of mice after LPS challenge

Bergapten (BG) is a cumarine-derivate compound in many medicinal plants. Here, in vitro and in vivo experimental results indicated that BG possesses anti-inflammatory properties, Based on this, we further investigated the precise molecular mechanisms of BG in LPS-stimulated inflammation response. Studies revealed that BG inhibited LPS-stimulated productions of TNF-α, IL-1β, IL-6, PGE2 and NO as well as the expression of iNOS and COX-2, and at the same time, it increased LPS-induced release of IL-10 in a dose-dependent manner in RAW264.7 cells. Mechanistically, BG suppressed the activations of JAK/STAT, but not that of MAPKs and NF-κB. In addition, BG, as an antioxidant, prevented the accumulation of ROS, which further exerted its anti-inflammatory function. In vivo researches revealed that BG decreased LPS-induced mortality in mice. In conclusions, BG may be a potential candidate for inflammation therapy via inhibiting JAK/STAT activation and ROS production in RAW264.7 cells.

Pharmacological evaluation of 9,10-dihydrochromeno[8,7-e][1,3]oxazin-2(8H)-one derivatives as potent anti-inflammatory agent

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely administered drugs for the treatment of inflammation. However, they usually cause some unexpected side effects. Coumarins and their derivatives exhibit broad-spectrum biological activities. In order to develop new anti-inflammatory drugs with high anti-inflammatory activity and less side effects, a series of 9-substituted-9,10-dihydrochromeno[8,7-e][1,3]oxazin-2(8H)-one derivatives were designed, synthesized, and screened for their anti-inflammatory activities.

METHODS

We investigated the effect of compound 9-(2-chlorophenyl)-9,10-dihydrochromeno[8,7-e][1,3]oxazin-2(8H)-one (B3) on lipopolysaccharide (LPS)-induced cytokine levels in RAW 264.7 cells at concentrations between 6.25 μg/ml and 25 μg/ml. Concentrations of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Moreover, mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) activation was investigated by western blot assay.

RESULTS

Compound B3 could inhibit inflammatory responses via suppression of the NF-κB and MAPK signaling pathways. Docking study of the prepared compounds was performed for the study of interaction of molecules with the active site of TNF-α.

CONCLUSION

9,10-Dihydrochromeno[8,7-e][1,3]oxazin-2(8H)-one derivatives showed anti-inflammatory activity. Compound B3 was the most potent. The results of this study are encouraging further investigations to develop compound B3 as a novel therapeutic agent for inflammatory disorders.

Aspirin-Triggered Resolvin D1-modified materials promote the accumulation of pro-regenerative immune cell subsets and enhance vascular remodeling

Many goals in tissue engineering rely on modulating cellular localization and polarization of cell signaling, including the inhibition of inflammatory infiltrate, facilitation of inflammatory cell egress, and clearance of apoptotic cells. Omega-3 polyunsaturated fatty acid-derived resolvins are gaining increasing recognition for their essential roles in inhibition of neutrophil invasion into inflamed tissue and promotion of macrophage phagocytosis of cellular debris as well as their egress to the lymphatics. Biomaterial-based release of lipid mediators is a largely under-explored approach that provides a method to manipulate local lipid signaling gradients in vivo and direct the recruitment and/or polarization of anti-inflammatory cell subsets to suppress inflammatory signaling and enhance angiogenesis and tissue regeneration. The goal of this study was to encapsulate Aspirin-Triggered Resolvin D1 (AT-RvD1) into a degradable biomaterial in order to elucidate the effects of sustained, localized delivery in a model of sterile inflammation. Flow cytometric and imaging analysis at both 1 and 3days after injury showed that localized AT-RvD1 delivery was able significantly increase the accumulation of anti-inflammatory monocytes and M2 macrophages while limiting the infiltration of neutrophils. Additionally, cytokine profiling and longitudinal vascular analysis revealed a shift towards a pro-angiogenic profile with increased concentrations of VEGF and SDF-1α, and increased arteriolar diameter and tortuosity. These results demonstrate the ability of locally-delivered AT-RvD1 to increase pro-regenerative immune subpopulations and promote vascular remodeling.

STATEMENT OF SIGNIFICANCE

This work is motivated by our efforts to explore the underlying mechanisms of inflammation resolution after injury and to develop biomaterial-based approaches to amplify endogenous mechanisms of resolution and repair. Though specific lipid mediators have been identified that actively promote the resolution of inflammation, biomaterial-based localized delivery of these mediators has been largely unexplored. We loaded Aspirin-Triggered Resolvin D1 into a PLGA scaffold and examined the effects of sustained, localized delivery on the innate immune response. We found that biomaterial delivery of resolvin was able to enhance the accumulation of pro-regenerative populations of immune cells, including anti-inflammatory monocytes, population that has never before been shown to respond to resolvin treatment, and also enhance vascular remodeling in response to tissue injury.

Neuroendocrinology of mast cells: Challenges and controversies

Mast cells (MC) are hemotopoietically derived tissue immune cells that are ubiquitous in the body, including neuroendocrine organs such as the hypothalamus, pineal, pituitary, ovaries, pancreas and uterus where their action is not well understood. Mast cells have historically been associated with allergies because of their rich content of histamine and tryptase, but more recently with regulation of immunity and inflammation due to their synthesis and release of numerous cytokines and chemokines. Mast cells are located perivascularly and express numerous receptors for diverse ligands such as allergens, pathogens, neurotransmitters, neuropeptides and hormones including acetylcholine, calcitonin gene-related peptide (CGRP), corticosteroids, corticotropin-releasing hormone (CRH), β-endorphin, epinephrine, 17β-oestradiol, gonadotrophins, hemokinin-A (HKA), leptin, melatonin, neurotensin (NT), parathyroid hormone (PTH), substance P (SP) and vasoactive intestinal peptide (VIP). Moreover, MC can synthesize and release most of their neurohormonal triggers, including adrenocorticotropin hormone (ACTH), CRH, endorphins, HKA, leptin, melatonin, NT, SP and VIP. Animal experiments have shown that diencephalic MC increase in number during courting in doves, while stimulation of brain and nasal MC leads to activation of the hypothalamic-pituitary-adrenal (HPA) axis. Recent evidence indicates that MC reactivity exhibits diurnal variations, and it is interesting that melatonin appears to regulate MC secretion. However, the way MC change their phenotype or secrete specific molecules selectively at different pathophysiological settings still remains unknown. Mast cells developed over 500 million years ago and may have served as the original prototype neuroimmunoendocrine cell and then evolved into a master regulator of such interactions, especially as most of the known diseases involve neuroinflammation that worsens with stress.

Regulation of mRNA stability by CCCH-type zinc-finger proteins in immune cells

Current studies using knockout mice have revealed that some Cys-Cys-Cys-His (CCCH)-type zinc-finger proteins, namely tristetraprolin (TTP), Roquin and Regnase-1, play important roles in the immune system. These proteins are closely associated with the fate of their target RNAs in normal immune responses. However, the functions of many RNA-binding proteins have not been characterized precisely. To understand the molecular mechanisms of RNA metabolism in the immune system, investigation of TTP/Roquin/Regnase-1 might provide new knowledge. In this review, we will discuss the current understanding of these proteins in immune regulation and homeostasis and discuss RNA metabolism in the immune system.

Activation of PPARγ inhibits pro-inflammatory cytokines production by upregulation of miR-124 in vitro and in vivo

Peroxisome proliferator-activated receptor gamma (PPARγ) and miR-124 have been reported to play important roles in regulation of inflammation. However, the underlying anti-inflammatory mechanisms remain not well understood. In the present study, we demonstrated that the expression level of PPARγ is positively correlated with that of miR-124 in patients with sepsis. Activation of PPARγ upregulates miR-124 and in turn inhibits miR-124 target gene. PPARγ bound directly to PPRE in the miR-124 promoter region, and enhanced the promoter transcriptional activity. PPARγ-induced miR-124 is involved in the suppression of pro-inflammatory cytokine in vitro and in vivo. These results suggest that PPARγ-induced miR-124 inhibits the production of pro-inflammatory cytokines is a novel PPARγ anti-inflammatory mechanism and also indicate that miR-124 may be a potential therapeutic target for the treatment of inflammatory diseases.

Self-renewal and phenotypic conversion are the main physiological responses of macrophages to the endogenous estrogen surge

Beyond the physiology of reproduction, estrogen controls the homeostasis of several tissues. Although macrophages play a key role in tissue remodeling, the interplay with estrogen is still ill defined. Using a transcriptomic approach we first obtained a comprehensive list of genes that are differentially expressed in peritoneal macrophages in response to physiological levels of 17β-estradiol (E₂) injected in intact female mice. Our data also showed the dynamic nature of the macrophage response to E₂ and pointed to specific biological programs induced by the hormone, with cell proliferation, immune response and wound healing being the most prominent functional categories. Indeed, the exogenous administration of E₂ and, more importantly, the endogenous hormonal surge proved to support macrophage proliferation in vivo, as shown by cell cycle gene expression, BrdU incorporation and cell number. Furthermore, E₂ promoted an anti-inflammatory and pro-resolving macrophage phenotype, which converged on the induction of genes related to macrophage alternative activation and on IL-10 expression in vivo. Hormone action was maintained in an experimental model of peritoneal inflammation based on zymosan injection. These findings highlight a direct effect of estrogen on macrophage expansion and phenotypic adaptation in homeostatic conditions and suggest a role for this interplay in inflammatory pathologies.

CCL2 nitration is a negative regulator of chemokine-mediated inflammation

Chemokines promote leukocyte recruitment during inflammation. The oxidative burst is an important effector mechanism, this leads to the generation of reactive nitrogen species (RNS), including peroxynitrite (ONOO). The current study was performed to determine the potential for nitration to alter the chemical and biological properties of the prototypical CC chemokine, CCL2. Immunofluorescence was performed to assess the presence of RNS in kidney biopsies. Co-localisation was observed between RNS-modified tyrosine residues and the chemokine CCL2 in diseased kidneys. Nitration reduced the potential of CCL2 to stimulate monocyte migration in diffusion gradient chemotaxis assays (p < 0.05). This was consistent with a trend towards reduced affinity of the nitrated chemokine for its cognate receptor CCR2b. The nitrated chemokine was unable to induce transendothelial monocyte migration in vitro and failed to promote leukocyte recruitment when added to murine air pouches (p < 0.05). This could potentially be attributed to reduced glycosaminoglycan binding ability, as surface plasmon resonance spectroscopy showed that nitration reduced heparan sulphate binding by CCL2. Importantly, intravenous administration of nitrated CCL2 also inhibited the normal recruitment of leukocytes to murine air pouches filled with unmodified CCL2. Together these data suggest that nitration of CCL2 during inflammation provides a mechanism to limit and resolve acute inflammation.

Effect of lipid-bound apolipoprotein A-I cysteine mutant on ATF3 in RAW264.7 cells

Activating transcription factor 3 (ATF3) is a TLR-induced repressor that plays an important role in the inhibition of specific inflammatory signals. We previously constructed recombinant high density lipoproteins (rHDL) (including rHDL_WT, rHDL_M, rHDL₂₂₈ and rHDL₇₄) and found that rHDL₇₄ had a strong anti-inflammatory ability. In the present study, we investigate the roles of recombinant apolipoprotein A-I (ApoA-I) (rHDL_WT) and its cysteine mutant HDLs (rHDL_M, rHDL₂₂₈ and rHDL₇₄) on ATF3 function in RAW264.7 cells stimulated by lipopolysaccharide. Our results showed that compared with the LPS group, rHDL₇₄ can decrease the level of TNF-α and IL-6, whereas rHDL₂₂₈ increases their expression levels. RT-PCR and Western blotting results showed that compared with the LPS group, rHDL₇₄, rHDL_WT and rHDL_M can markedly increase the expression level of ATF3, whereas the level of ATF3 decreases in the rHDL₂₂₈ group. In summary, the different anti-inflammatory mechanisms of the ApoA-I cysteine mutants might be associated with the regulation of ATF3 level.

Stellera chamaejasme and its constituents induce cutaneous wound healing and anti-inflammatory activities

Stellera chamaejasme L. (Thymelaeaceae) is a perennial herb that is widely used in traditional Chinese medicine to treat tumours, tuberculosis and psoriasis. S. chamaejasme extract (SCE) possesses anti-inflammatory, analgesic and wound healing activities; however, the effect of S. chamaejasme and its active compounds on cutaneous wound healing has not been investigated. We assessed full-thickness wounds of Sprague-Dawley (SD) rats and topically applied SCE for 2 weeks. In vitro studies were performed using HaCaT keratinocytes, Hs68 dermal fibroblasts and RAW 264.7 macrophages to determine cell viability (MTT assay), cell migration, collagen expression, nitric oxide (NO) production, prostaglandin E₂ (PGE₂) production, inflammatory cytokine expression and β-catenin activation. In vivo, wound size was reduced and epithelisation was improved in SCE-treated SD rats. In vitro, SCE and its active compounds induced keratinocyte migration by regulating the β-catenin, extracellular signal-regulated kinase and Akt signalling pathways. Furthermore, SCE and its active compounds increased mRNA expression of type I and III collagen in Hs68 fibroblasts. SCE and chamechromone inhibited NO and PGE₂ release and mRNA expression of inflammatory mediators in RAW 264.7 macrophages. SCE enhances the motility of HaCaT keratinocytes and improves cutaneous wound healing in SD rats.

The lipidome in major depressive disorder: Shared genetic influence for ether-phosphatidylcholines, a plasma-based phenotype related to inflammation, and disease risk

BACKGROUND

The lipidome is rapidly garnering interest in the field of psychiatry. Recent studies have implicated lipidomic changes across numerous psychiatric disorders. In particular, there is growing evidence that the concentrations of several classes of lipids are altered in those diagnosed with MDD. However, for lipidomic abnormalities to be considered potential treatment targets for MDD (rather than secondary manifestations of the disease), a shared etiology between lipid concentrations and MDD should be demonstrated.

METHODS

In a sample of 567 individuals from 37 extended pedigrees (average size 13.57 people, range=3-80), we used mass spectrometry lipidomic measures to evaluate the genetic overlap between twenty-three biologically distinct lipid classes and a dimensional scale of MDD.

RESULTS

We found that the lipid class with the largest endophenotype ranking value (ERV, a standardized parametric measure of pleiotropy) were ether-phosphodatidylcholines (alkylphosphatidylcholine, PC(O) and alkenylphosphatidylcholine, PC(P) subclasses). Furthermore, we examined the cluster structure of the twenty-five species within the top-ranked lipid class, and the relationship of those clusters with MDD. This analysis revealed that species containing arachidonic acid generally exhibited the greatest degree of genetic overlap with MDD.

CONCLUSIONS

This study is the first to demonstrate a shared genetic etiology between MDD and ether-phosphatidylcholine species containing arachidonic acid, an omega-6 fatty acid that is a precursor to inflammatory mediators, such as prostaglandins. The study highlights the potential utility of the well-characterized linoleic/arachidonic acid inflammation pathway as a diagnostic marker and/or treatment target for MDD.

Ulinastatin downregulates TLR4 and NF-kB expression and protects mouse brains against ischemia/reperfusion injury

BACKGROUND

Inflammatory damage plays an important role in ischemic stroke and provides potential targets for therapy. Ulinastatin (UTI), a drug used to treat shock and acute pancreatitis in clinic, has attracted attention for its protective effects through immunomodulatory and anti-inflammatory properties. However, the effect of UTI in the acute phase of cerebral ischemia/reperfusion (I/R) is not clear. This study is to investigate the potential neuroprotective effect of UTI and explore its underlying mechanisms.

METHODS

Male CD-1 mice were subjected to transient middle cerebral artery occlusion (tMCAO) and randomly assigned into four groups: Sham (sham-operated) group, tMCAO (tMCAO + 0.9% saline) group, UTI-L (tMCAO + UTI 1500 U/100 g), and UTI-H (tMCAO + UTI 3000 U/100 g) group. UTI was administered immediately after reperfusion in the UTI-L and UTI-H groups. About 24 h after the reperfusion, the neurological deficit, brain water content, and infarct volume were detected. Immunohistochemistry, western blot and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to detect the expression of TLR4 and NF-κB in the ischemic cerebral cortex.

RESULTS

Compared with tMCAO group, both UTI-L and UTI-H groups dramatically ameliorated neurological deficit (p < 0.05), lessened the brain water content (p < 0.05) and infarct volume (p < 0.05), and decreased the expression of TLR4 and NF-κB.

CONCLUSION

These results showed that UTI protected the brain against ischemic injury which may be due to the alleviation of inflammation reaction in early stage through downregulating TLR4 and NF-κB expression.

Solving the puzzle: What is behind our forefathers' anti-inflammatory remedies?

Inflammation is a ubiquitous host response in charge of restoring normal tissue structure and function but is a double-edged sword, as the uncontrolled or excessive process can lead to the injury of host cells, chronic inflammation, chronic diseases, and also neoplastic transformation. Throughout history, a wide range of species has been claimed to have anti-inflammatory effects worldwide. Among them, Angelica sinensis, Tropaeolum majus, Castilleja tenuiflora, Biophytum umbraculum, to name just a few, have attracted the scientific and general public attention in the last years. Efforts have been made to assess their relevance through a scientific method. However, inflammation is a complex interdependent process, and phytomedicines are complex mixtures of compounds with multiple mechanisms of biological actions, which restricts systematic explanation. For this purpose, the omics techniques could prove extremely useful. They provide tools for interpreting and integrating results from both the classical medical tradition and modern science. As a result, the concept of network pharmacology applied to phytomedicines emerged. All of this is a step toward personalized therapy.

The Potential Therapeutic Application of Peptides and Peptidomimetics in Cardiovascular Disease

Cardiovascular disease (CVD) remains a leading cause of mortality and morbidity worldwide. Numerous therapies are currently under investigation to improve pathological cardiovascular complications, but yet, there have been very few new medications approved for intervention/treatment. Therefore, new approaches to treat CVD are urgently required. Attempts to prevent vascular complications usually involve amelioration of contributing risk factors and underlying processes such as inflammation, obesity, hyperglycaemia, or hypercholesterolemia. Historically, the development of peptides as therapeutic agents has been avoided by the Pharmaceutical industry due to their low stability, size, rate of degradation, and poor delivery. However, more recently, resurgence has taken place in developing peptides and their mimetics for therapeutic intervention. As a result, increased attention has been placed upon using peptides that mimic the function of mediators involved in pathologic processes during vascular damage. This review will provide an overview on novel targets and experimental therapeutic approaches based on peptidomimetics for modulation in CVD. We aim to specifically examine apolipoprotein A-I (apoA-I) and apoE mimetic peptides and their role in cholesterol transport during atherosclerosis, suppressors of cytokine signaling (SOCS)1-derived peptides and annexin-A1 as potent inhibitors of inflammation, incretin mimetics and their function in glucose-insulin tolerance, among others. With improvements in technology and synthesis platforms the future looks promising for the development of novel peptides and mimetics for therapeutic use. However, within the area of CVD much more work is required to identify and improve our understanding of peptide structure, interaction, and function in order to select the best targets to take forward for treatment.

The protective effects of Shikonin on lipopolysaccharide/d-galactosamine-induced acute liver injury via inhibiting MAPK and NF-κB and activating Nrf2/HO-1 signaling pathways

Shikonin (SHK) has various biological and pharmacological activities, including anticancer, antibacterial and anti-inflammation activities.

Inflammation and epigenetic regulation in osteoarthritis

Osteoarthritis (OA) was once defined as a non-inflammatory arthropathy, but it is now well-recognized that there is a major inflammatory component to this disease. In addition to synovial cells, articular chondrocytes and other cells of diarthrodial joints are also known to express inflammatory mediators. It has been proposed that targeting inflammation pathways could be a promising strategy to treat OA. There have been many reports of cross-talk between inflammation and epigenetic factors in cartilage. Specifically, inflammatory mediators have been shown to regulate levels of enzymes that catalyze changes in DNA methylation and histone structure, as well as alter levels of non-coding RNAs. In addition, expression levels of a number of these epigenetic factors have been shown to be altered in OA, thereby suggesting potential interplay between inflammation and epigenetics in this disease. This review provides information on inflammatory pathways in arthritis and summarizes published research on how epigenetic regulators are affected by inflammation in chondrocytes. Furthermore, we discuss data showing how altered expression of some of these epigenetic factors can induce either catabolic or anti-catabolic effects in response to inflammatory signals. A better understanding of how inflammation affects epigenetic factors in OA may provide us with novel therapeutic strategies to treat this condition.

3-Methoxy-catalposide inhibits inflammatory effects in lipopolysaccharide-stimulated RAW264.7 macrophages

Pseudolysimachion rotundum var. subintegrum is utilized as a traditional herbal remedy to treat cough, bronchitis, and asthma in Korea, Russia, China, and Europe. Here, we show that 3-methoxy-catalposide, a novel iridoide glycoside isolated from P. rotundum var. subintegrum has the anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated macrophages. The chemical structure of 3-methoxy-catalposide was determined by NMR, optical rotation and HRESIMS. In in vitro experiment, RAW264.7 cells were treated with 3-methoxy-catalposide for 2h before exposure to LPS for different times. Inflammatory gene and protein expressions were assayed using RT-PCR and ELISA. Activities of signal proteins were examined using western analysis. Our results demonstrated that 3-methoxy-catalposide significantly inhibits the expression of cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) in RAW264.7 cells stimulated by LPS, thereby suppressing the release of prostaglandin E2 (PGE₂) and nitric oxide (NO). Moreover, 3-methoxy-catalposide markedly reduced the LPS-induced expression of pro-inflammatory genes, such as interleukin (IL)-6, IL-1β, and TNF-α. Further, 3-methoxy-catalposide inhibited both LPS-induced activation of three MAP kinases (ERK 1/2, JNK, and p38) and the nuclear translocation of NF-κB and AP-1. These results support that 3-methoxy-catalposide may be a promising candidate for inflammation treatment.