Macrophage responses to lipopolysaccharide are modulated by a feedback loop involving prostaglandin E2, dual specificity phosphatase 1 and tristetraprolin

Paravertebrally-Injected Multifunctional Hydrogel for Sustained Anti-Inflammation and Pain Relief in Lumbar Disc Herniation

Pain caused by lumbar disc herniation (LDH) severely compromises patients' quality of life. The combination of steroid and local anesthetics is routinely employed in clinics to alleviate LDH-induced pain. However, the approach only mediates transient efficacy and requires repeated and invasive lumbar epidural injections. Here a paravertebrally-injected multifunctional hydrogel that can efficiently co-load and controlled release glucocorticoid betamethasone and anesthetics ropivacaine for sustained anti-inflammation, reactive oxygen species (ROS)-removal and pain relief in LDH is presented. Betamethasone is conjugated to hyaluronic acid (HA) via ROS-responsive crosslinker to form amphiphilic polymer that self-assemble into particles with ropivacaine loaded into the core. Solution of drug-loaded particles and thermo-sensitive polymer rapidly forms therapeutic hydrogel in situ upon injection next to the herniated disc, thus avoiding invasive epidural injection. In a rat model of LDH, multifunctional hydrogel maintains the local drug concentration 72 times longer than free drugs and more effectively inhibits the expression of pro-inflammatory cytokines and pain-related molecules including cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). Therapeutic hydrogel suppresses the LDH-induced pain in rats for 12 days while the equivalent dose of free drugs is only effective for 3 days. This platform is also applicable to ameliorate pain caused by other spine-related diseases.

Inhibition of macrophage MAPK/NF-κB pathway and Th2 axis by mangiferin ameliorates MC903-induced atopic dermatitis

Available online Atopic dermatitis (AD) is a chronic, persistent inflammatory skin disease characterized by eczema-like lesions and itching. Although topical steroids have been reported for treating AD, they are associated with adverse effects. Thus, safer medications are needed for those who cannot tolerate these agents for long periods. Mangiferin (MAN) is a flavonoid widely found in many herbs, with significant anti-inflammatory and immunomodulatory activities. However, the potential modulatory effects and mechanisms of MAN in treating Th2 inflammation in AD are unknown. In the present study, we reported that MAN could reduce inflammatory cell infiltration and scratching at the lesion site by decreasing MC903-induced levels of Th2-type cytokines, Histamine, thymic stromal lymphopoietin, Leukotriene B4, and immunoglobulin E. The mechanism may be related to reductions in MAPK and NF-κB-associated protein phosphorylation by macrophages. The results suggested that MAN may be a promising therapeutic agent for AD.

DUSP1/MKP-1 represents another piece in the P2X7R intracellular signaling puzzle in cerebellar cells: our last journey with Mª Teresa along the purinergic pathways of Eden

The P2X7 receptor (P2X7R) stands out within the purinergic family as it has exclusive pharmacological and regulatory features, and it fulfills distinct roles depending on the type of stimulation and cellular environment. Tonic activation of P2X7R promotes cell proliferation, whereas sustained activation is associated with cell death. Yet strikingly, prolonged P2X7R activation in rat cerebellar granule neurons and astrocytes does not affect cell survival. The intracellular pathways activated by P2X7Rs involve proteins like MAPKs, ERK1/2 and p38, and interactions with growth factor receptors could explain their behavior in populations of rat cerebellar cells. In this study, we set out to characterize the intracellular mechanisms through which P2X7Rs and Trk receptors, EGFR (epidermal growth factor receptor) and BDNFR (brain-derived neurotrophic factor receptor), regulate the dual-specificity phosphatase DUSP1. In cerebellar astrocytes, the regulation of DUSP1 expression by P2X7R depends on ERK and p38 activation. EGFR stimulation can also induce DUSP1 expression, albeit less strongly than P2X7R. Conversely, EGF was virtually ineffective in regulating DUSP1 in granule neurons, a cell type in which BDNF is the main regulator of DUSP1 expression and P2X7R only induces a mild response. Indeed, the regulation of DUSP1 elicited by BDNF reflects the balance between both transcriptional and post-transcriptional mechanisms. Importantly, when the regulation of DUSP1 expression is compromised, the viability of both astrocytes and neurons is impaired, suggesting this phosphatase is essential to maintain proper cell cytoarchitecture and functioning.

Aquaporins (AQPs) as a marker in the physiology of inflammation and its interaction studies with garcinol

Aquaporins like AQP1, AQP3, and AQP4 are known to be involved in the pathophysiology of inflammation based on earlier reports. This study aimed to evaluate the involvement of Aquaporins as a potential target of inflammation. The study also investigates the efficacy of methanolic extract of Garcinia (GME) and its potent phytocompound (garcinol) against the Aquaporins involved in inflammation. siRNA silencing of AQP3 was carried out in RAW264.7 cells followed by LPS stimulation (1 µg/ml) and assessment of important markers of inflammation including NO, PGE2, TNF-α, IL-6, IL-1β, CCL20, iNOS and COX-2. To assess the anti-inflammatory potential of Garcinia extract and garcinol, cells were stimulated with 1 µg/ml LPS in the absence and presence of increasing concentrations of GME and garcinol. During the experimental period, extract concentrations (115 µg/ml and 230 µg/ml for RAW264.7; 118 µg/ml and 236 µg/ml for THP-1) and garcinol concentrations (6 µM and 12 µM for RAW264.7; 3 µM and 6 µM for THP-1) were selected based on the IC50. The anti-inflammatory effects were assessed by measuring the levels of TNF-α, IL-1β, IL-6, and CCL20 in LPS-stimulated cells. The AQP expression was studied at transcriptional and translational levels using qPCR and Western blot analysis respectively. AQP3 knockdown significantly decreased the NO, PGE2, TNF-α, IL-1β levels along with iNOS and COX-2 mRNA expression. LPS stimulation led to a significant increase in the mRNA and protein level expression AQP1, AQP3, and AQP4 in RAW264.7 cells; and AQP1 and AQP3 in THP-1 cells indicating their role as markers of inflammation. GME and garcinol effectively suppressed the LPS-induced proinflammatory cytokine production in both cell lines. The results indicate that AQP1, AQP3, and AQP4 could play a crucial role as markers of inflammation. Anti-inflammatory agents like Garcinia could potentially decrease the expression of such AQPs, thus inhibiting the inflammatory process.

Arachidonic acid inhibition of the NLRP3 inflammasome is a mechanism to explain the anti-inflammatory effects of fasting

Elevated interleukin (IL)-1β levels, NLRP3 inflammasome activity, and systemic inflammation are hallmarks of chronic metabolic inflammatory syndromes, but the mechanistic basis for this is unclear. Here, we show that levels of plasma IL-1β are lower in fasting compared to fed subjects, while the lipid arachidonic acid (AA) is elevated. Lipid profiling of NLRP3-stimulated mouse macrophages shows enhanced AA production and an NLRP3-dependent eicosanoid signature. Inhibition of cyclooxygenase by nonsteroidal anti-inflammatory drugs decreases eicosanoid, but not AA, production. It also reduces both IL-1β and IL-18 production in response to NLRP3 activation. AA inhibits NLRP3 inflammasome activity in human and mouse macrophages. Mechanistically, AA inhibits phospholipase C activity to reduce JNK1 stimulation and hence NLRP3 activity. These data show that AA is an important physiological regulator of the NLRP3 inflammasome and explains why fasting reduces systemic inflammation and also suggests a mechanism to explain how nonsteroidal anti-inflammatory drugs work.

Microbiota promotes recruitment and pro-inflammatory response of caecal macrophages during E. tenella infection

BACKGROUND

Eimeria genus belongs to the apicomplexan parasite phylum and is responsible for coccidiosis, an intestinal disease with a major economic impact on poultry production. Eimeria tenella is one of the most virulent species in chickens. In a previous study, we showed a negative impact of caecal microbiota on the physiopathology of this infection. However, the mechanism by which microbiota leads to the physiopathology remained undetermined. Macrophages play a key role in inflammatory processes and their interaction with the microbiota during E. tenella infection have never been investigated. We therefore examined the impact of microbiota on macrophages during E. tenella infection. Macrophages were monitored in caecal tissues by immunofluorescence staining with KUL01 antibody in non-infected and infected germ-free and conventional chickens. Caecal cells were isolated, stained, analyzed and sorted to examine their gene expression using high-throughput qPCR.

RESULTS

We demonstrated that microbiota was essential for caecal macrophage recruitment in E. tenella infection. Furthermore, microbiota promoted a pro-inflammatory transcriptomic profile of macrophages characterized by increased gene expression of NOS2, ACOD1, PTGS2, TNFα, IL1β, IL6, IL8L1, IL8L2 and CCL20 in infected chickens. Administration of caecal microbiota from conventional chickens to germ-free infected chickens partially restored macrophage recruitment and response.

CONCLUSIONS

Taken together, these results suggest that the microbiota enhances the physiopathology of this infection through macrophage recruitment and activation. Consequently, strategies involving modulation of the gut microbiota may lead to attenuation of the macrophage-mediated inflammatory response, thereby limiting the negative clinical outcome of the disease.

Damage-mediated macrophage polarization in sterile inflammation

Most of the leading causes of death, such as cardiovascular diseases, cancer, dementia, neurodegenerative diseases, and many more, are associated with sterile inflammation, either as a cause or a consequence of these conditions. The ability to control the progression of inflammation toward tissue resolution before it becomes chronic holds significant clinical potential. During sterile inflammation, the initiation of inflammation occurs through damage-associated molecular patterns (DAMPs) in the absence of pathogen-associated molecules. Macrophages, which are primarily localized in the tissue, play a pivotal role in sensing DAMPs. Furthermore, macrophages can also detect and respond to resolution-associated molecular patterns (RAMPs) and specific pro-resolving mediators (SPMs) during sterile inflammation. Macrophages, being highly adaptable cells, are particularly influenced by changes in the microenvironment. In response to the tissue environment, monocytes, pro-inflammatory macrophages, and pro-resolution macrophages can modulate their differentiation state. Ultimately, DAMP and RAMP-primed macrophages, depending on the predominant subpopulation, regulate the balance between inflammatory and resolving processes. While sterile injury and pathogen-induced reactions may have distinct effects on macrophages, most studies have focused on macrophage responses induced by pathogens. In this review, which emphasizes available human data, we illustrate how macrophages sense these mediators by examining the expression of receptors for DAMPs, RAMPs, and SPMs. We also delve into the signaling pathways induced by DAMPs, RAMPs, and SPMs, which primarily contribute to the regulation of macrophage differentiation from a pro-inflammatory to a pro-resolution phenotype. Understanding the regulatory mechanisms behind the transition between macrophage subtypes can offer insights into manipulating the transition from inflammation to resolution in sterile inflammatory diseases.

Amelioration of DSS-induced colitis in mice by TNF-α-stimulated mesenchymal stem cells derived from feline adipose tissue via COX-2/PGE2 activation

BACKGROUND

Mesenchymal stem cells (MSCs) have been investigated as therapeutic agents for inflammatory bowel disease (IBD). Stimulation of MSCs with pro-inflammatory cytokines is an approach to enhance their immunomodulatory effects. However, further investigation is required to support their application in immune-mediated disorders and companion animals.

OBJECTIVES

This study aimed to assess the therapeutic effect of tumor necrosis factor (TNF)-α-stimulated feline adipose tissue-derived MSCs (fAT-MSCs) in a dextran sulfate sodium (DSS)-induced colitis mouse model.

METHODS

Colitis mice was made by drinking water with 3% DSS and fAT-MSCs were injected intraperitoneally. Colons were collected on day 10. The severity of the disease was evaluated and compared. Raw 264.7 cells were cultured with the conditioned medium to determine the mechanism, using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS

TNF-α-stimulated fAT-MSCs more improved severity of DSS-induced colitis in disease activity, colon length, histologic score, and inflammatory cytokine. In sectionized colon tissues, the group comprising TNF-α-stimulated fAT-MSCs had higher proportion of CD11b+CD206+ macrophages than in the other groups. In vitro, TNF-α-stimulation increased cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) secretion from fAT-MSCs. The conditioned medium from TNF-α-stimulated fAT-MSCs enhanced the expression of interleukin-10 and arginase-1 in LPS-activated Raw 264.7 cells.

CONCLUSIONS

These results represent that TNF-α-stimulated fat-mscs ameliorate the inflamed colon more effectively. Furthermore, we demonstrated that the effectiveness was interlinked with the COX-2/PGE2 pathway.

Caffeic acid methyl ester inhibits mast cell activation through the suppresion of MAPKs and NF-κB signaling in RBL-2H3 cells

Anti-inflammatory effects of caffeic acid derivatives have been widely reported. However, the effect of caffeic acid methyl ester (CAME) on the anti-allergic effect in mast cells has not been elucidated. The present study was aimed to investigate the anti-allergic properties of CAME and its underlying mechanism. Rat basophilic leukemia (RBL-2H3) cells were incubated withphorbol-12-myristate-13-acetate (PMA) and a calcium ionophore, A23187 to induce mast cell activation. Anti-allergic effect of CAME was examined by measuring cytokine, histamine and β-hexosaminidase release. Western blotting was conducted to determine cyclooxygenase-2 (COX-2) expression, Mitogen-activated protein kinases (MAPKs) activation and nuclear factor-κB (NF-κB) translocation. CAME significantly suppressed PMA/A23187-induced TNF-α secretion, and β-hexosaminidase and histamine release in a concentration-dependent manner. Furthermore, CAME significantly attenuated PMA/A23187-induced COX-2 expression and nuclear translocation of NF-κB. CAME significantly suppressed PMA/A23187-induced increased phosphorylation of p38, ERK and JNK RBL-2H3 cells. The results demonstrate that CAME significantly attenuates anti-allergic action by suppressing degranulation of mast cells through the suppression of MAPKs/NF-κB signaling pathway in RBL-2H3 cells.

Updates on Tumor Biology in Vestibular Schwannoma

Vestibular schwannomas (VSs) are benign tumors that develop after biallelic inactivation of the neurofibromatosis type 2 (NF2) gene that encodes the tumor suppressor merlin. Merlin inactivation leads to cell proliferation by dysregulation of receptor tyrosine kinase signaling and other intracellular pathways. In VS without NF2 mutations, dysregulation of non-NF2 genes can promote pathways favoring cell proliferation and tumorigenesis. The tumor microenvironment of VS consists of multiple cell types that influence VS tumor biology through complex intercellular networking and communications.

Resistance to Prostaglandin E2 Promotes Monocyte Activation During Chronic HIV Infection

BACKGROUND

Monocyte activation is a driver of inflammation in the course of chronic HIV infection. Prostaglandin E2 (PGE2) is known to mediate anti-inflammatory effects, notably the inhibition of tumor necrosis factor- (TNF-) production by monocytes. We aim to investigate the effects of PGE2 on activation of monocytes in chronic HIV infection and the mechanisms through which PGE2 modulates their inflammatory signature.

METHODS

We recruited a group of people with HIV (PWH) and matched healthy uninfected persons. We compared plasma levels of PGE2, monocyte activation, and sensitivity of monocytes to the inhibitory actions mediated by PGE2.

RESULTS

We found increased plasma levels of PGE2 in PWH, and an activated phenotype in circulating monocytes, compared with uninfected individuals. Monocytes from PWH showed a significant resistance to the inhibitory actions mediated by PGE2; the concentration of PGE2 able to inhibit 50 of the production of TNF- by lipopolysaccharide-stimulated monocytes was 10 times higher in PWH compared with uninfected controls. Furthermore, the expression of phosphodiesterase 4B, a negative regulator of PGE2 activity, was significantly increased in monocytes from PWH.

CONCLUSIONS

Resistance to the inhibitory actions mediated by PGE2 could account, at least in part, for the inflammatory profile of circulating monocytes in PWH.

Endotoxin tolerance and low activation of TLR-4/NF-κB axis in monocytes of COVID-19 patients

Higher endotoxin in the circulation may indicate a compromised state of host immune response against coinfections in severe COVID-19 patients. We evaluated the inflammatory response of monocytes from COVID-19 patients after lipopolysaccharide (LPS) challenge. Whole blood samples of healthy controls, patients with mild COVID-19, and patients with severe COVID-19 were incubated with LPS for 2 h. Severe COVID-19 patients presented higher LPS and sCD14 levels in the plasma than healthy controls and mild COVID-19 patients. In non-stimulated in vitro condition, severe COVID-19 patients presented higher inflammatory cytokines and PGE-2 levels and CD14 + HLA-DR^low monocytes frequency than controls. Moreover, severe COVID-19 patients presented higher NF-κB p65 phosphorylation in CD14 + HLA-DR^low, as well as higher expression of TLR-4 and NF-κB p65 phosphorylation in CD14 + HLA-DR^high compared to controls. The stimulation of LPS in whole blood of severe COVID-19 patients leads to lower cytokine production but higher PGE-2 levels compared to controls. Endotoxin challenge with both concentrations reduced the frequency of CD14 + HLA-DR^low in severe COVID-19 patients, but the increases in TLR-4 expression and NF-κB p65 phosphorylation were more pronounced in both CD14 + monocytes of healthy controls and mild COVID-19 patients compared to severe COVID-19 group. We conclude that acute SARS-CoV-2 infection is associated with diminished endotoxin response in monocytes. KEY MESSAGES: Severe COVID-19 patients had higher levels of LPS and systemic IL-6 and TNF-α. Severe COVID-19 patients presented higher CD14+HLA-DRlow monocytes. Increased TLR-4/NF-κB axis was identified in monocytes of severe COVID-19. Blunted production of cytokines after whole blood LPS stimulation in severe COVID-19. Lower TLR-4/NF-κB activation in monocytes after LPS stimulation in severe COVID-19.

The effect of Dioscorea esculenta powder on prostaglandin E2 and cytochrome c oxidase subunit 2 levels, menstrual pain, and premenstrual syndrome in young women: A randomized double-blind controlled trial

Background Diosgenin, extracted from Dioscorea esculenta, has been reported to decrease prostaglandin E2 (PGE2) levels and any other inflammatory cytokine in rodents. However, it is still unclear whether D. esculenta intake suppressed PGE2 production and menstrual pain and premenstrual syndrome (PMS) in younger female. Aim This study aims to investigate the effect of D. esculenta intake on PGE2 and cytochrome c oxidase subunit 2 (COX-2) levels and on menstrual pain and PMS in young women. This is a randomized, double-blind, placebo-controlled, crossover study. Methods Ten healthy young females were administered either a placebo or D. esculenta (300 mg/day) for 4 weeks, followed by a 4-week washout period. Fasting blood sample was taken from the fingertips on the second day of menstrual cycle began and obtained 24h before the last D. esculenta to avoid acute effects. Participants then switched treatments for 4 weeks as a second trial. Plasma PGE2 and COX-2 levels were measured before and after each trial. The visual analogue scale (VAS), McGill pain questionnaire (MPQ), and Daily Record of Severity of Problems (DRSP) were also evaluated. The study was set and conducted from 2019 to 2020. Results PGE2 and COX-2 levels significantly decreased after D. esculenta intake compared to placebo (p = 0.038, p = 0.042 each). The VAS and DRSP scores were also significantly lower after D. esculenta intake (p = 0.046, p = 0.035 each). Conclusion Four-week D. esculenta intake suppressed PGE2 and COX-2 levels resulting in an improvement in PMS symptoms and menstrual pain in young women.

Periodontal Stem Cells Synthesize Maresin Conjugate in Tissue Regeneration 3

Periodontal disease is a significant public health problem worldwide. Excess unresolved chronic inflammation destroys the periodontal tissues that surround and support the teeth, and efforts to control inflammation by removal of bacterial deposits on the teeth have limited long-term impact. Likewise, procedures aimed at regeneration of the periodontal tissues have shown limited success. Recent advances in stem cell research have shown promising novel prospects for the use of periodontal ligament stem cells (PDLSCs) in tissue regeneration; however, control of inflammation remains a barrier. Human PDLSCs have been shown to release specialized proresolving lipid mediators (SPMs) that modulate the immune response and promote resolution of inflammation, tissue repair, and regeneration. Studies on stem cell biology in periodontology have also been limited by the lack of a good large animal model. Herein, we describe PDLSC biology of the Yorkshire pig (pPDLSCs). pPDLSCs were isolated and characterized. Using lipid mediator profiling, we demonstrate for the first time that pPDLSCs biosynthesize cysteinyl-containing SPMs (cys-SPMs), specifically, maresin conjugates in tissue regeneration 3 (MCTR3) and its authentication using liquid chromatography/tandem mass spectrometry. The exogenous addition of the n-3 precursor docosahexaenoic acid enhances MCTR3 biosynthesis. Using immunocytochemistry, we show that pPDLSCs express 4 of the SPM biosynthetic pathway enzymes necessary for SPM biosynthesis, including 5-lipoxygenase, 12-lipoxygenase, and 15-lipoxygenase-1. In addition, we identified and quantified the cytokine/chemokine profile of pPDLSCs using a 13-plex immunology multiplex assay and found that the pretreatment of pPDLSCs with MCTR3 in an inflammatory environment reduced the production of acute and chronic proinflammatory cytokines/chemokines. Together, these results suggest that enhancing resolution of inflammation pathways and mediators may be a possible key early event in predictable periodontal regeneration.

Cynanoside F Controls Skin Inflammation by Suppressing Mitogen-Activated Protein Kinase Activation

Atopic dermatitis (AD) is a chronic inflammatory skin disease accompanied by severe itching and dry skin. Currently, the incidence of AD due to excessive activation of immune cells by various environmental factors is increasing worldwide, and research on inflammatory response inhibitors with fewer side effects is continuously needed. Cynanoside F (CF) is one of the pregnane-type compounds in the root of Cynanchum atratum, an oriental medicinal herb that has been shown to have antioxidant, antitumor, and anti-inflammatory effects. Although CF has been isolated as a component in Cynanchum atratum, the scientific role of CF has not yet been explored. In this study, we evaluated the effect of CF on AD and revealed the mechanism using in vitro and in vivo experimental models. CF significantly reduced lipopolysaccharide (LPS)-induced protein expression levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2), which are important proinflammatory mediators in the RAW264.7 macrophage cell line. CF did not inhibit the nuclear factor-kappa B (NF-κB) signaling activated by LPS but significantly reduced the phosphorylation of mitogen-activated protein kinases (MAPKs), such as p38 MAPK, JNK, and ERK. CF consistently inhibited the activity of the activator protein-1 (AP-1) transcription factor, a downstream molecule of MAPK signaling. In addition, in an experiment using an oxazolone-induced AD mouse model, the CF-treated group showed a marked decrease in epidermal thickness, the number of infiltrated mast cells, and the amount of histamine. The mRNA levels of IL-1β, interleukin-4 (IL-4), and thymic stromal lymphopoietin (TSLP) were consistently lowered in the group treated with CF. Moreover, the phosphorylation of c-Jun and c-Fos protein levels, which are the AP-1 components, were lowered in the skin tissues of CF-treated mice. These results provide the first evidence that CF has an inhibitory effect on AD and suggest the possibility of CF being developed as a potential therapeutic agent for AD.

Microfluidic-driven mixing of high molecular weight polymeric complexes for precise nanoparticle downsizing

Chitosan (CHIT) and hyaluronic acid (HA) are two polysaccharides (PSs) with high value in several biomedical applications. In this study, we present a microfluidic method to synthetize CHIT-HA NPs to overcome the disadvantages of the dropwise approach generally used for nanoprecipitation of polyelectrolyte complexes. The proposed microfluidic approach enables to generate monodisperse suspensions of NPs with ≈100 nm of size compared to the dropwise method that generated ≈2 times bigger NPs. Finally, we evaluated the potential of obtained NPs in an inflammatory scenario. The treatment with NPs led to the reduction of the main inflammatory molecules produced by macrophages (PGE₂, IL-6, IL-8, MCAF and TNF-α) and fibroblasts (IL-1 α, PGE₂, TNF-α) stimulated with lipopolysaccharide or conditioned medium, respectively. This study demonstrates that our approach can be used to enhance the synthesis of nanocarriers based on bioactive macromolecules.

Three-dimensional feature matching improves coverage for single-cell proteomics based on ion mobility filtering

Single-cell proteomics (scProteomics) promises to advance our understanding of cell functions within complex biological systems. However, a major challenge of current methods is their inability to identify and provide accurate quantitative information for low-abundance proteins. Herein, we describe an ion-mobility-enhanced mass spectrometry acquisition and peptide identification method, transferring identification based on FAIMS filtering (TIFF), to improve the sensitivity and accuracy of label-free scProteomics. TIFF extends the ion accumulation times for peptide ions by filtering out singly charged ions. The peptide identities are assigned by a three-dimensional MS1 feature matching approach (retention time, accurate mass, and FAIMS compensation voltage). The TIFF method enabled unbiased proteome analysis to a depth of >1,700 proteins in single HeLa cells, with >1,100 proteins consistently identified. As a demonstration, we applied the TIFF method to obtain temporal proteome profiles of >150 single murine macrophage cells during lipopolysaccharide stimulation and identified time-dependent proteome changes. A record of this paper's transparent peer review process is included in the supplemental information.

Molecular docking prediction and in vitro studies elucidate anti-inflammatory effect of Garcinia extract against inducible nitric oxide synthase and cyclooxygenase-2 targets

Background

Garcinia is a tropical plant that has been traditionally used in medicinal folklore for its potential antioxidant, antibacterial, anti-hyperlipidemic, anti-diabetic, hepatoprotective, etc. In this study, methanolic extract of Garcinia herbal supplement (GME) and its important phytoconstituents (Garcinol and hydroxycitric acid) were evaluated for their inhibitory action against important inflammatory markers iNOS and COX-2 in lipopolysaccharide-induced RAW 264.7 cells. iNOS and COX-2 play a major role in the process of inflammation, and inhibition of these molecules will help to alleviate the inflammatory process. The cells were pre-treated with two doses of GME (115 µg/ml and 230 µg/ml); Ggarcinol (6 µM and 12 µM); hydroxycitric acid (17.5 µg/ml and 35 µg/ml) followed by stimulation with 1 µg/ml of LPS for 24 h.

Results

The results of the study demonstrated that Garcinia and its active components Garcinol and HCA play an important role in suppressing LPS-induced relative mRNA expression of iNOS, COX-2, and subsequent reduction in the levels of total nitric oxide and prostaglandinE2. Molecular docking analysis of Ggarcinol and HCA with iNOS and COX-2 proteins showed potent interactions with negative binding energies.

Conclusions

This study suggests that Garcinia possess anti-inflammatory activity thus providing a possibility for drug designing as iNOS and COX-2 inhibitor.

Graphical Abstract

Oleacein Attenuates Lipopolysaccharide-Induced Inflammation in THP-1-Derived Macrophages by the Inhibition of TLR4/MyD88/NF-κB Pathway

It is known that plant phenolic compounds exert anti-inflammatory activity through both anti-oxidant effects and modulation of pivotal pro-inflammatory factors. Recently, Olea europaea has been studied as a natural source of bioactive molecules; however, few studies have focused on the biological effect of oleacein (OLC), the most abundant secoiridoid. Therefore, the aim of this study was to investigate the potential anti-oxidant activity of OLC, as well as to study its anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated THP-1-derived macrophages. LPS brought a dramatic increase of both release and gene expression of pro-inflammatory cytokines (IL-6, IL-1β and TNF-α), as well as a decrease of anti-inflammatory ones (IL-10), the effects of which are reverted by OLC. Moreover, it reduced the levels of COX-2, NO and PGE₂ elicited by LPS exposure in THP-1 macrophages. Interestingly, OLC modulated inflammatory signaling pathways through the inhibition of CD14/TLR4/CD14/MyD88 axis and the activation of NF-κB. Finally, OLC showed relevant anti-oxidant capability, assessed by abiotic assays, and reduced the intracellular amount of ROS generated by LPS exposure in THP-1 macrophages. Overall, these results suggest that the anti-oxidant activity and anti-inflammatory effect of OLC may cooperate in its protective effect against inflammatory stressors, thus being a possible alternative pharmacological strategy aimed at reducing the inflammatory process.

Macrophage COX2 Mediates Efferocytosis, Resolution Reprogramming, and Intestinal Epithelial Repair

BACKGROUND AND AIMS

Phagocytosis (efferocytosis) of apoptotic neutrophils by macrophages anchors the resolution of intestinal inflammation. Efferocytosis prevents secondary necrosis and inhibits further inflammation, and also reprograms macrophages to facilitate tissue repair and promote resolution function. Macrophage efferocytosis and efferocytosis-dependent reprogramming are implicated in the pathogenesis of inflammatory bowel disease. We previously reported that absence of macrophage cyclooxygenase 2 (COX2) exacerbates inflammatory bowel disease-like intestinal inflammation. To elucidate the underlying pathogenic mechanism, we investigated here whether COX2 mediates macrophage efferocytosis and efferocytosis-dependent reprogramming, including intestinal epithelial repair capacity.

METHODS

Using apoptotic neutrophils and synthetic apoptotic targets, we determined the effects of macrophage specific Cox2 knockout and pharmacological COX2 inhibition on the efferocytosis capacity of mouse primary macrophages. COX2-mediated efferocytosis-dependent eicosanoid lipidomics was determined by liquid chromatography tandem mass spectrometry. Small intestinal epithelial organoids were employed to assay the effects of COX2 on efferocytosis-dependent intestinal epithelial repair.

RESULTS

Loss of COX2 impaired efferocytosis in mouse primary macrophages, in part, by affecting the binding capacity of macrophages for apoptotic cells. This effect was comparable to that of high-dose lipopolysaccharide and was accompanied by both dysregulation of macrophage polarization and the inhibited expression of genes involved in apoptotic cell binding. COX2 modulated the production of efferocytosis-dependent lipid inflammatory mediators that include the eicosanoids prostaglandin I2, prostaglandin E2, lipoxin A4, and 15d-PGJ2; and further affected secondary efferocytosis. Finally, macrophage efferocytosis induced, in a macrophage COX2-dependent manner, a tissue restitution and repair phenotype in intestinal epithelial organoids.

CONCLUSIONS

Macrophage COX2 potentiates efferocytosis capacity and efferocytosis-dependent reprogramming, facilitating macrophage intestinal epithelial repair capacity.

Bioactive Diterpenes, Norditerpenes, and Sesquiterpenes from a Formosan Soft Coral Cespitularia sp

Chemical investigation of the soft coral Cespitularia sp. led to the discovery of twelve new verticillane-type diterpenes and norditerpenes: cespitulins H–O (1–8), one cyclic diterpenoidal amide cespitulactam L (9), norditerpenes cespitulin P (10), cespitulins Q and R (11 and 12), four new sesquiterpenes: cespilins A–C (13–15) and cespitulolide (16), along with twelve known metabolites. The structures of these metabolites were established by extensive spectroscopic analyses, including 2D NMR experiments. Anti-inflammatory effects of the isolated compounds were studied by evaluating the suppression of pro-inflammatory protein tumor necrosis factor-α (TNF-α) and nitric oxide (NO) overproduction, and the inhibition of the gene expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in lipopolysaccharide-induced dendritic cells. A number of these metabolites were found to exhibit promising anti-inflammatory activities.

Macrophage metabolic regulation in atherosclerotic plaque

Metabolism plays a key role in controlling immune cell functions. In this review, we will discuss the diversity of plaque resident myeloid cells and will focus on their metabolic demands that could reflect on their particular intraplaque localization. Defining the metabolic configuration of plaque resident myeloid cells according to their topologic distribution could provide answers to key questions regarding their functions and contribution to disease development.

Physiologically relevant aspirin concentrations trigger immunostimulatory cytokine production by human leukocytes

Acetylsalicylic acid is a globally used non-steroidal anti-inflammatory drug (NSAID) with diverse pharmacological properties, although its mechanism of immune regulation during inflammation (especially at in vivo relevant doses) remains largely speculative. Given the increase in clinical perspective of Acetylsalicylic acid in various diseases and cancer prevention, this study aimed to investigate the immunomodulatory role of physiological Acetylsalicylic acid concentrations (0.005, 0.02 and 0.2 mg/ml) in a human whole blood of infection-induced inflammation. We describe a simple, highly reliable whole blood assay using an array of toll-like receptor (TLR) ligands 1–9 in order to systematically explore the immunomodulatory activity of Acetylsalicylic acid plasma concentrations in physiologically relevant conditions. Release of inflammatory cytokines and production of prostaglandin E₂ (PGE₂) were determined directly in plasma supernatant. Experiments demonstrate for the first time that plasma concentrations of Acetylsalicylic acid significantly increased TLR ligand-triggered IL-1β, IL-10, and IL-6 production in a dose-dependent manner. In contrast, indomethacin did not exhibit this capacity, whereas cyclooxygenase (COX)-2 selective NSAID, celecoxib, induced a similar pattern like Acetylsalicylic acid, suggesting a possible relevance of COX-2. Accordingly, we found that exogenous addition of COX downstream product, PGE₂, attenuates the TLR ligand-mediated cytokine secretion by augmenting production of anti-inflammatory cytokines and inhibiting release of pro-inflammatory cytokines. Low PGE₂ levels were at least involved in the enhanced IL-1β production by Acetylsalicylic acid.

Impaired immune response mediated by prostaglandin E2 promotes severe COVID-19 disease

The SARS-CoV-2 coronavirus has led to a pandemic with millions of people affected. The present study finds that risk-factors for severe COVID-19 disease courses, i.e. male sex, older age and sedentary life style are associated with higher prostaglandin E2 (PGE2) serum levels in blood samples from unaffected subjects. In COVID-19 patients, PGE2 blood levels are markedly elevated and correlate positively with disease severity. SARS-CoV-2 induces PGE2 generation and secretion in infected lung epithelial cells by upregulating cyclo-oxygenase (COX)-2 and reducing the PG-degrading enzyme 15-hydroxyprostaglandin-dehydrogenase. Also living human precision cut lung slices (PCLS) infected with SARS-CoV-2 display upregulated COX-2. Regular exercise in aged individuals lowers PGE2 serum levels, which leads to increased Paired-Box-Protein-Pax-5 (PAX5) expression, a master regulator of B-cell survival, proliferation and differentiation also towards long lived memory B-cells, in human pre-B-cell lines. Moreover, PGE2 levels in serum of COVID-19 patients lowers the expression of PAX5 in human pre-B-cell lines. The PGE2 inhibitor Taxifolin reduces SARS-CoV-2-induced PGE2 production. In conclusion, SARS-CoV-2, male sex, old age, and sedentary life style increase PGE2 levels, which may reduce the early anti-viral defense as well as the development of immunity promoting severe disease courses and multiple infections. Regular exercise and Taxifolin treatment may reduce these risks and prevent severe disease courses.

Prostanoids and Resolution of Inflammation - Beyond the Lipid-Mediator Class Switch

Bioactive lipid mediators play a major role in regulating inflammatory processes. Herein, early pro-inflammatory phases are characterized and regulated by prostanoids and leukotrienes, whereas specialized pro-resolving mediators (SPM), including lipoxins, resolvins, protectins, and maresins, dominate during the resolution phase. While pro-inflammatory properties of prostanoids have been studied extensively, their impact on later phases of the inflammatory process has been attributed mainly to their ability to initiate the lipid-mediator class switch towards SPM. Yet, there is accumulating evidence that prostanoids directly contribute to the resolution of inflammation and return to homeostasis. In this mini review, we summarize the current knowledge of the resolution-regulatory properties of prostanoids and discuss potential implications for anti-inflammatory, prostanoid-targeted therapeutic interventions.

Post-Transcriptional Regulation of Immune Responses and Inflammatory Diseases by RNA-Binding ZFP36 Family Proteins

Post-transcriptional regulation is involved in the regulation of many inflammatory genes. Zinc finger protein 36 (ZFP36) family proteins are RNA-binding proteins involved in messenger RNA (mRNA) metabolism pathways. The ZFP36 family is composed of ZFP36 (also known as tristetraprolin, TTP), ZFP36L1, ZFP36L2, and ZFP36L3 (only in rodents). The ZFP36 family proteins contain two tandemly repeated CCCH-type zinc-finger motifs, bind to adenine uridine-rich elements in the 3’-untranslated regions (3’ UTR) of specific mRNA, and lead to target mRNA decay. Although the ZFP36 family members are structurally similar, they are known to play distinct functions and regulate different target mRNAs, probably due to their cell-type-specific expression patterns. For instance, ZFP36 has been well-known to function as an anti-inflammatory modulator in murine models of systemic inflammatory diseases by down-regulating the production of various pro-inflammatory cytokines, including TNF-α. Meanwhile, ZFP36L1 is required for the maintenance of the marginal-zone B cell compartment. Recently, we found that ZFP36L2 reduces the expression of Ikzf2 (encoding HELIOS) and suppresses regulatory T cell function. This review summarizes the current understanding of the post-transcriptional regulation of immunological responses and inflammatory diseases by RNA-binding ZFP36 family proteins.

Comparative Anti-Inflammatory Effects of Salix Cortex Extracts and Acetylsalicylic Acid in SARS-CoV-2 Peptide and LPS-Activated Human In Vitro Systems

The usefulness of anti-inflammatory drugs as an adjunct therapy to improve outcomes in COVID-19 patients is intensely discussed in this paper. Willow bark (Salix cortex) has been used for centuries to relieve pain, inflammation, and fever. Its main active ingredient, salicin, is metabolized in the human body into salicylic acid, the precursor of the commonly used pain drug acetylsalicylic acid (ASA). Here, we report on the in vitro anti-inflammatory efficacy of two methanolic Salix extracts, standardized to phenolic compounds, in comparison to ASA in the context of a SARS-CoV-2 peptide challenge. Using SARS-CoV-2 peptide/IL-1β- or LPS-activated human PBMCs and an inflammatory intestinal Caco-2/HT29-MTX co-culture, Salix extracts, and ASA concentration-dependently suppressed prostaglandin E2 (PGE₂), a principal mediator of inflammation. The inhibition of COX-2 enzyme activity, but not protein expression was observed for ASA and one Salix extract. In activated PBMCs, the suppression of relevant cytokines (i.e., IL-6, IL-1β, and IL-10) was seen for both Salix extracts. The anti-inflammatory capacity of Salix extracts was still retained after transepithelial passage and liver cell metabolism in an advanced co-culture model system consisting of intestinal Caco-2/HT29-MTX cells and differentiated hepatocyte-like HepaRG cells. Taken together, our in vitro data suggest that Salix extracts might present an additional anti-inflammatory treatment option in the context of SARS-CoV-2 peptides challenge; however, more confirmatory data are needed.

Applications of Lipidomics to Age-Related Musculoskeletal Disorders

PURPOSE OF REVIEW

The goal of this review is to highlight the need for new biomarkers for the diagnosis and treatment of musculoskeletal disorders, especially osteoporosis and sarcopenia. These conditions are characterized by loss of bone and muscle mass, respectively, leading to functional deterioration and the development of disabilities. Advances in high-resolution lipidomics platforms are being used to help identify new lipid biomarkers for these diseases.

RECENT FINDINGS

It is now well established that bone and muscle have important endocrine functions, including the release of bioactive factors in response to mechanical and biochemical stimuli. Bioactive lipids are a prominent set of these factors and some of these lipids are directly related to the mass and function of bone and muscle. Recent lipidomics studies have shown significant dysregulation of lipids in aged muscle and bone, including alterations in diacylglycerols and ceramides. Studies have shown that alterations in some types of plasma lipids are associated with aging including reduced bone mineral density and the occurrence of osteoporosis. Musculoskeletal disorders are a major burden in our society, especially for older adults. The development and application of new lipidomics methods is making significant advances in identifying new biomarkers for these diseases. These studies will not only lead to improved detection, but new mechanistic insights that could lead to new therapeutic targets and interventions.

Comparisons of Extracellular Vesicles from Human Epidural Fat-Derived Mesenchymal Stem Cells and Fibroblast Cells

Extracellular vesicles (EVs) are generated and secreted by cells into the circulatory system. Stem cell-derived EVs have a therapeutic effect similar to that of stem cells and are considered an alternative method for cell therapy. Accordingly, research on the characteristics of EVs is emerging. EVs were isolated from human epidural fat-derived mesenchymal stem cells (MSCs) and human fibroblast culture media by ultracentrifugation. The characterization of EVs involved the typical evaluation of cluster of differentiation (CD antigens) marker expression by fluorescence-activated cell sorting, size analysis with dynamic laser scattering, and morphology analysis with transmission electron microscopy. Lastly, the secreted levels of cytokines and chemokines in EVs were determined by a cytokine assay. The isolated EVs had a typical size of approximately 30–200 nm, and the surface proteins CD9 and CD81 were expressed on human epidural fat MSCs and human fibroblast cells. The secreted levels of cytokines and chemokines were compared between human epidural fat MSC-derived EVs and human fibroblast-derived EVs. Human epidural fat MSC-derived EVs showed anti-inflammatory effects and promoted macrophage polarization. In this study, we demonstrated for the first time that human epidural fat MSC-derived EVs exhibit inflammatory suppressive potency relative to human fibroblast-derived EVs, which may be useful for the treatment of inflammation-related diseases.

Longitudinal transcriptomics define the stages of myeloid activation in the living human brain after intracerebral hemorrhage

Opportunities to interrogate the immune responses in the injured tissue of living patients suffering from acute sterile injuries such as stroke and heart attack are limited. We leveraged a clinical trial of minimally invasive neurosurgery for patients with intracerebral hemorrhage (ICH), a severely disabling subtype of stroke, to investigate the dynamics of inflammation at the site of brain injury over time. Longitudinal transcriptional profiling of CD14⁺ monocytes/macrophages and neutrophils from hematomas of patients with ICH revealed that the myeloid response to ICH within the hematoma is distinct from that in the blood and occurs in stages conserved across the patient cohort. Initially, hematoma myeloid cells expressed a robust anabolic proinflammatory profile characterized by activation of hypoxia-inducible factors (HIFs) and expression of genes encoding immune factors and glycolysis. Subsequently, inflammatory gene expression decreased over time, whereas anti-inflammatory circuits were maintained and phagocytic and antioxidative pathways up-regulated. During this transition to immune resolution, glycolysis gene expression and levels of the potent proresolution lipid mediator prostaglandin E₂ remained elevated in the hematoma, and unexpectedly, these elevations correlated with positive patient outcomes. Ex vivo activation of human macrophages by ICH-associated stimuli highlighted an important role for HIFs in production of both inflammatory and anti-inflammatory factors, including PGE₂, which, in turn, augmented VEGF production. Our findings define the time course of myeloid activation in the human brain after ICH, revealing a conserved progression of immune responses from proinflammatory to proresolution states in humans after brain injury and identifying transcriptional programs associated with neurological recovery.

Functions of ROS in Macrophages and Antimicrobial Immunity

Reactive oxygen species (ROS) are a chemically defined group of reactive molecules derived from molecular oxygen. ROS are involved in a plethora of processes in cells in all domains of life, ranging from bacteria, plants and animals, including humans. The importance of ROS for macrophage-mediated immunity is unquestioned. Their functions comprise direct antimicrobial activity against bacteria and parasites as well as redox-regulation of immune signaling and induction of inflammasome activation. However, only a few studies have performed in-depth ROS analyses and even fewer have identified the precise redox-regulated target molecules. In this review, we will give a brief introduction to ROS and their sources in macrophages, summarize the versatile roles of ROS in direct and indirect antimicrobial immune defense, and provide an overview of commonly used ROS probes, scavengers and inhibitors.

The cancer metabolic reprogramming and immune response

The overlapping metabolic reprogramming of cancer and immune cells is a putative determinant of the antitumor immune response in cancer. Increased evidence suggests that cancer metabolism not only plays a crucial role in cancer signaling for sustaining tumorigenesis and survival, but also has wider implications in the regulation of antitumor immune response through both the release of metabolites and affecting the expression of immune molecules, such as lactate, PGE₂, arginine, etc. Actually, this energetic interplay between tumor and immune cells leads to metabolic competition in the tumor ecosystem, limiting nutrient availability and leading to microenvironmental acidosis, which hinders immune cell function. More interestingly, metabolic reprogramming is also indispensable in the process of maintaining self and body homeostasis by various types of immune cells. At present, more and more studies pointed out that immune cell would undergo metabolic reprogramming during the process of proliferation, differentiation, and execution of effector functions, which is essential to the immune response. Herein, we discuss how metabolic reprogramming of cancer cells and immune cells regulate antitumor immune response and the possible approaches to targeting metabolic pathways in the context of anticancer immunotherapy. We also describe hypothetical combination treatments between immunotherapy and metabolic intervening that could be used to better unleash the potential of anticancer therapies.

A proprietary herbal extract titred in verbascoside and aucubin suppresses lipopolysaccharide-stimulated expressions of cyclooxygenase-2 in human neutrophils

Introduction

Bacterial lipopolysaccharide (LPS) initiates several major cellular responses that play a crucial role in the pathogenesis of inflammation, including activation of neutrophils and production of prostaglandin E2 (PGE2) by cyclooxygenase-2 (COX-2).

Material and methods

Recent years have witnessed a growing interest in natural compounds as promising alternatives to synthetic COX-2 inhibitors. In this study, we sought to investigate the effect of a proprietary herbal extract from Lippia citriodora and Plantago lanceolata, titred in verbascoside (≥ 5%) and aucubin (≥ 2%), against LPS-stimulated expressions of COX-2 in human neutrophils using both reverse transcription-polymerase chain reaction (RT-PCR) and a PGE2 immunoassay.

Results

Our main results indicated that: 1. The proprietary herbal extract titred in verbascoside and aucubin is not significantly cytotoxic as shown by the MTT assay; 2. The extract does not significantly inhibit COX-1, whereas it is able to suppress LPS-elicited COX-2 hyperexpression at the mRNA level in human neutrophils; and 3. The effect of the extract at 5% concentration was comparable to that elicited celecoxib 1%, although, in terms of absolute and relative reduction of COX-2 mRNA expression and production of PGE2 in human neutrophils, the drug significantly outperformed the extract.

Conclusions

In general, these results suggest that the proprietary herbal extract titred in verbascoside and aucubin is safe and may possess significant anti-inflammatory and analgesic effects by acting as a specific COX-2 inhibitor. Further studies are required to confirm the clinical efficacy of the extract.

Role of Tristetraprolin in the Resolution of Inflammation

Simple Summary

Chronic inflammatory diseases account for up to 60% of deaths worldwide and, thus, are considered a great threat for human health by the World Health Organization. Nevertheless, acute inflammatory reactions are an integral part of the host defense against invading pathogens or injuries. To avoid excessive damage due to the persistence of a highly reactive environment, inflammations need to resolve in a coordinate and timely manner, ensuring for the immunological normalization of the affected tissues. Since post-transcriptional regulatory mechanisms are essential for effective resolution, the present review discusses the key role of the RNA-binding and post-transcriptional regulatory protein tristetraprolin in establishing resolution of inflammation.

Abstract

Inflammation is a crucial part of immune responses towards invading pathogens or tissue damage. While inflammatory reactions are aimed at removing the triggering stimulus, it is important that these processes are terminated in a coordinate manner to prevent excessive tissue damage due to the highly reactive inflammatory environment. Initiation of inflammatory responses was proposed to be regulated predominantly at a transcriptional level, whereas post-transcriptional modes of regulation appear to be crucial for resolution of inflammation. The RNA-binding protein tristetraprolin (TTP) interacts with AU-rich elements in the 3′ untranslated region of mRNAs, recruits deadenylase complexes and thereby facilitates degradation of its targets. As TTP regulates the mRNA stability of numerous inflammatory mediators, it was put forward as a crucial post-transcriptional regulator of inflammation. Here, we summarize the current understanding of the function of TTP with a specific focus on its role in adding to resolution of inflammation.

Biofunctionalization of 3D-printed silicone implants with immunomodulatory hydrogels for controlling the innate immune response: An in vivo model of tracheal defect repair

The recent advances in 3D-printed silicone (PDMS: polydimethylsiloxane) implants present prospects for personalized implants with highly accurate anatomical conformity. However, a potential adverse effect, such as granuloma formation due to immune reactions, still exists. One potential way to overcome this problem is to control the implant/host interface using immunomodulatory coatings. In this study, a new cytokine cocktail composed of interleukin-10 and prostaglandin-E2 was designed to decrease adverse immune reactions and promote tissue integration by fixing macrophages into M2 pro-healing phenotype for an extended period of time. In vitro, the cytokine cocktail maintained low levels of pro-inflammatory cytokine (TNF-α and IL-6) secretions and induced the secretion of IL-10 and the upregulation of multifunctional scavenging and sorting receptor stabilin-1, expressed by M2 macrophages. This cocktail was then loaded in a gelatine-based hydrogel to develop an immunomodulatory material that could be used as a coating for medical devices. The efficacy of this coating was demonstrated in an in vivo rat model during the reconstruction of a tracheal defect by 3D-printed silicone implants. The coating was stable on the silicone implants for over 2 weeks, and the controlled release of the cocktail components was achieved for at least 14 days. In vivo, only 33% of the animals with bare silicone implants survived, whereas 100% of the animals survived with the implant equipped with the immunomodulatory hydrogel. The presence of the hydrogel and the cytokine cocktail diminished the thickness of the inflammatory tissue, the intensity of both acute and chronic inflammation, the overall fibroblastic reaction, the presence of oedema and the formation of fibrinoid (assessed by histology) and led to a 100% survival rate. At the systemic level, the presence of immunomodulatory hydrogels significantly decreased pro-inflammatory cytokines such as TNF-α, IFN-γ, CXCL1 and MCP-1 levels at day 7 and significantly decreased IL-1α, IL-1β, CXCL1 and MCP-1 levels at day 21. The ability of this new immunomodulatory hydrogel to control the level of inflammation once applied to a 3D-printed silicone implant has been demonstrated. Such thin coatings can be applied to any implants or scaffolds used in tissue engineering to diminish the initial immune response, improve the integration and functionality of these materials and decrease potential complications related to their presence.

Impact of A Cargo-Less Liposomal Formulation on Dietary Obesity-Related Metabolic Disorders in Mice

Current therapeutic options for obesity often require pharmacological intervention with dietary restrictions. Obesity is associated with underlying inflammation due to increased tissue macrophage infiltration, and recent evidence shows that inflammation can drive obesity, creating a feed forward mechanism. Therefore, targeting obesity-induced macrophage infiltration may be an effective way of treating obesity. Here, we developed cargo-less liposomes (UTS-001) using 1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC (synthetic phosphatidylcholine) as a single-agent to manage weight gain and related glucose disorders due to high fat diet (HFD) consumption in mice. UTS-001 displayed potent immunomodulatory properties, including reducing resident macrophage number in both fat and liver, downregulating liver markers involved in gluconeogenesis, and increasing marker involved in thermogenesis. As a result, UTS-001 significantly enhanced systemic glucose tolerance in vivo and insulin-stimulated cellular glucose uptake in vitro, as well as reducing fat accumulation upon ad libitum HFD consumption in mice. UTS-001 targets tissue residence macrophages to suppress tissue inflammation during HFD-induced obesity, resulting in improved weight control and glucose metabolism. Thus, UTS-001 represents a promising therapeutic strategy for body weight management and glycaemic control.

DGLA from the Microalga Lobosphaera Incsa P127 Modulates Inflammatory Response, Inhibits iNOS Expression and Alleviates NO Secretion in RAW264.7 Murine Macrophages

Microalgae have been considered as a renewable source of nutritional, cosmetic and pharmaceutical compounds. The ability to produce health-beneficial long-chain polyunsaturated fatty acids (LC-PUFA) is of high interest. LC-PUFA and their metabolic lipid mediators, modulate key inflammatory pathways in numerous models. In particular, the metabolism of arachidonic acid under inflammatory challenge influences the immune reactivity of macrophages. However, less is known about another omega-6 LC-PUFA, dihomo-γ-linolenic acid (DGLA), which exhibits potent anti-inflammatory activities, which contrast with its delta-5 desaturase product, arachidonic acid (ARA). In this work, we examined whether administrating DGLA would modulate the inflammatory response in the RAW264.7 murine macrophage cell line. DGLA was applied for 24 h in the forms of carboxylic (free) acid, ethyl ester, and ethyl esters obtained from the DGLA-accumulating delta-5 desaturase mutant strain P127 of the green microalga Lobosphaera incisa. DGLA induced a dose-dependent increase in the RAW264.7 cells’ basal secretion of the prostaglandin PGE1. Upon bacterial lipopolysaccharide (LPS) stimuli, the enhanced production of pro-inflammatory cytokines, tumor necrosis factor alpha (TNFα) and interleukin 1β (IL-1β), was affected little by DGLA, while interleukin 6 (IL-6), nitric oxide, and total reactive oxygen species (ROS) decreased significantly. DGLA administered at 100 µM in all forms attenuated the LPS-induced expression of the key inflammatory genes in a concerted manner, in particular iNOS, IL-6, and LxR, in the form of free acid. PGE1 was the major prostaglandin detected in DGLA-supplemented culture supernatants, whose production prevailed over ARA-derived PGE2 and PGD2, which were less affected by LPS-stimulation compared with the vehicle control. An overall pattern of change indicated DGLA’s induced alleviation of the inflammatory state. Finally, our results indicate that microalgae-derived, DGLA-enriched ethyl esters (30%) exhibited similar activities to DGLA ethyl esters, strengthening the potential of this microalga as a potent source of this rare anti-inflammatory fatty acid.

Inflammatory macrophage memory in nonsteroidal anti-inflammatory drug-exacerbated respiratory disease

BACKGROUND

Nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD) is a chronic inflammatory condition, which is driven by an aberrant arachidonic acid metabolism. Macrophages are major producers of arachidonic acid metabolites and subject to metabolic reprogramming, but they have been neglected in N-ERD.

OBJECTIVE

This study sought to elucidate a potential metabolic and epigenetic macrophage reprogramming in N-ERD.

METHODS

Transcriptional, metabolic, and lipid mediator profiles in macrophages from patients with N-ERD and healthy controls were assessed by RNA sequencing, Seahorse assays, and LC-MS/MS. Metabolites in nasal lining fluid, sputum, and plasma from patients with N-ERD (n = 15) and healthy individuals (n = 10) were quantified by targeted metabolomics analyses. Genome-wide methylomics were deployed to define epigenetic mechanisms of macrophage reprogramming in N-ERD.

RESULTS

This study shows that N-ERD monocytes/macrophages exhibit an overall reduction in DNA methylation, aberrant metabolic profiles, and an increased expression of chemokines, indicative of a persistent proinflammatory activation. Differentially methylated regions in N-ERD macrophages included genes involved in chemokine signaling and acylcarnitine metabolism. Acylcarnitines were increased in macrophages, sputum, nasal lining fluid, and plasma of patients with N-ERD. On inflammatory challenge, N-ERD macrophages produced increased levels of acylcarnitines, proinflammatory arachidonic acid metabolites, cytokines, and chemokines as compared to healthy macrophages.

CONCLUSIONS

Together, these findings decipher a proinflammatory metabolic and epigenetic reprogramming of macrophages in N-ERD.

Inflammatory Responses during Tumour Initiation: From Zebrafish Transgenic Models of Cancer to Evidence from Mouse and Man

The zebrafish is now an important model organism for cancer biology studies and provides unique and complementary opportunities in comparison to the mammalian equivalent. The translucency of zebrafish has allowed in vivo live imaging studies of tumour initiation and progression at the cellular level, providing novel insights into our understanding of cancer. Here we summarise the available transgenic zebrafish tumour models and discuss what we have gleaned from them with respect to cancer inflammation. In particular, we focus on the host inflammatory response towards transformed cells during the pre-neoplastic stage of tumour development. We discuss features of tumour-associated macrophages and neutrophils in mammalian models and present evidence that supports the idea that these inflammatory cells promote early stage tumour development and progression. Direct live imaging of tumour initiation in zebrafish models has shown that the intrinsic inflammation induced by pre-neoplastic cells is tumour promoting. Signals mediating leukocyte recruitment to pre-neoplastic cells in zebrafish correspond to the signals that mediate leukocyte recruitment in mammalian tumours. The activation state of macrophages and neutrophils recruited to pre-neoplastic cells in zebrafish appears to be heterogenous, as seen in mammalian models, which provides an opportunity to study the plasticity of innate immune cells during tumour initiation. Although several potential mechanisms are described that might mediate the trophic function of innate immune cells during tumour initiation in zebrafish, there are several unknowns that are yet to be resolved. Rapid advancement of genetic tools and imaging technologies for zebrafish will facilitate research into the mechanisms that modulate leukocyte function during tumour initiation and identify targets for cancer prevention.

Inhibitory Effect of Probenecid on Osteoclast Formation via JNK, ROS and COX-2

Probenecid is a representative drug used in the treatment of gout. A recent study showed that probenecid effectively inhibits oxidative stress in neural cells. In the present study, we investigated whether probenecid can affect osteoclast formation through the inhibition of reactive oxygen species (ROS) formation in RAW264.7 cells. Lipopolysaccharide (LPS)-induced ROS levels were dose-dependently reduced by probenecid. Fluorescence microscopy analysis clearly showed that probenecid inhibits the generation of ROS. Western blot analysis indicated that probenecid affects two downstream signaling molecules of ROS, cyclooxygenase 2 (COX-2) and c-Jun N-terminal kinase (JNK). These results indicate that probenecid inhibits ROS generation and exerts antiosteoclastogenic activity by inhibiting the COX-2 and JNK pathways. These results suggest that probenecid could potentially be used as a therapeutic agent to prevent bone resorption.

Protein phosphatase 2A as a therapeutic target in inflammation and neurodegeneration

Protein phosphatase 2A (PP2A) is a highly complex heterotrimeric enzyme that catalyzes the selective removal of phosphate groups from protein serine and threonine residues. Emerging evidence suggests that it functions as a tumor suppressor by constraining phosphorylation-dependent signalling pathways that regulate cellular transformation and metastasis. Therefore, PP2A-activating drugs (PADs) are being actively sought and investigated as potential novel anti-cancer treatments. Here we explore the concept that PP2A also constrains inflammatory responses through its inhibitory effects on various signalling pathways, suggesting that PADs may be effective in the treatment of inflammation-mediated pathologies.

Role of Dual-Specificity Phosphatase 1 in Glucocorticoid-Driven Anti-inflammatory Responses

Glucocorticoids (GCs) potently inhibit pro-inflammatory responses and are widely used for the treatment of inflammatory diseases, such as allergies, autoimmune disorders, and asthma. Dual-specificity phosphatase 1 (DUSP1), also known as mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1), exerts its effects by dephosphorylation of MAPKs, i.e., extracellular-signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). Endogenous DUSP1 expression is tightly regulated at multiple levels, involving both transcriptional and post-transcriptional mechanisms. DUSP1 has emerged as a central mediator in the resolution of inflammation, and upregulation of DUSP1 by GCs has been suggested to be a key mechanism of GC actions. In this review, we discuss the impact of DUSP1 on the efficacy of GC-mediated suppression of inflammation and address the underlying mechanisms.

Sparks Fly in PGE2-Modulated Macrophage Polarization

How macrophages convey extracellular signals by bridging metabolism and functions remains unclear. In this issue of Immunity, Sanin et al. (2018) report that prostaglandin E2 (PGE2) treatment in interleukin-4-activated macrophages suppresses mitochondrial membrane potential to control voltage-regulated genes involved in proliferation and immune responses.

Prostaglandin E2, but not cAMP nor β2-agonists, induce tristetraprolin (TTP) in human airway smooth muscle cells

Tristetraprolin (TTP) is an anti-inflammatory molecule known to post-transcriptionally regulate cytokine production and is, therefore, an attractive drug target for chronic respiratory diseases driven by inflammation, such as asthma and chronic obstructive pulmonary disease. Our recent in vitro studies in primary human airway smooth (ASM) cells have confirmed the essential anti-inflammatory role played by TTP as a critical partner in a cytokine regulatory network. However, several unanswered questions remain. While prior in vitro studies have suggested that TTP is regulated in a cAMP-mediated manner, raising the possibility that this may be one of the ways in which β₂-agonists achieve beneficial effects beyond bronchodilation, the impact of β₂-agonists on ASM cells is unknown. Furthermore, the effect of prostaglandin E₂ (PGE₂) on TTP expression in ASM cells has not been reported. We address this herein and reveal, for the first time, that TTP is not regulated by cAMP-activating agents nor following treatment with long-acting β₂-agonists. However, PGE₂ does induce TTP mRNA expression and protein upregulation in ASM cells. Although the underlying mechanism of action remains undefined, we can confirm that PGE₂-induced TTP upregulation is not mediated via cAMP, or EP₂/EP₄ receptor activation, and occurred in a manner independent of the p38 MAPK-mediated pathway. Taken together, these data confirm that β₂-agonists do not upregulate TTP in human ASM cells and indicate that another way in which PGE₂ may achieve beneficial effects in asthma and COPD may be via upregulation of the master controller of inflammation-TTP.

Dietary arachidonate in milk replacer triggers dual benefits of PGE2 signaling in LPS-challenged piglet alveolar macrophages

Background

Respiratory infections challenge the swine industry, despite common medicinal practices. The dual signaling nature of PGE₂ (supporting both inflammation and resolution) makes it a potent regulator of immune cell function. Therefore, the use of dietary long chain n-6 PUFA to enhance PGE₂ effects merits investigation.

Methods

Day-old pigs (n = 60) were allotted to one of three dietary groups for 21 d (n = 20/diet), and received either a control diet (CON, arachidonate = 0.5% of total fatty acids), an arachidonate (ARA)-enriched diet (LC n-6, ARA = 2.2%), or an eicosapentaenoic (EPA)-enriched diet (LC n-3, EPA = 3.0%). Alveolar macrophages and lung parenchymal tissue were collected for fatty acid analysis. Isolated alveolar macrophages were stimulated with LPS in situ for 24 h, and mRNA was isolated to assess markers associated with inflammation and eicosanoid production. Culture media were collected to assess PGE₂ secretion. Oxidative burst in macrophages was measured by: 1) oxygen consumption and extracellular acidification (via Seahorse), 2) cytoplasmic oxidation and 3) nitric oxide production following 4, 18, and 24 h of LPS stimulation.

Results

Concentration of ARA (% of fatty acids, w/w) in macrophages from pigs fed LC n-6 was 86% higher than CON and 18% lower in pigs fed LC n-3 (P < 0.01). Following LPS stimulation, abundance of COX-2 and TNF-α mRNA (P <  0.0001), and PGE₂ secretion (P < 0. 01) were higher in LC n-6 PAM vs. CON. However, ALOX5 abundance was 1.6-fold lower than CON. Macrophages from CON and LC n-6 groups were 4-fold higher in ALOX12/15 abundance (P < 0.0001) compared to LC n-3. Oxygen consumption and extracellular acidification rates increased over 4 h following LPS stimulation (P < 0.05) regardless of treatment. Similarly, increases in cytoplasmic oxidation (P < 0.001) and nitric oxide production (P <  0.002) were observed after 18 h of LPS stimulation but were unaffected by diet.

Conclusions

We infer that enriching diets with arachidonic acid may be an effective means to enhance a stronger innate immunologic response to respiratory challenges in neonatal pigs. However, further work is needed to examine long-term safety, clinical efficacy and economic viability.

Electronic supplementary material

The online version of this article (10.1186/s40104-019-0321-1) contains supplementary material, which is available to authorized users.

Progesterone and cAMP synergize to inhibit responsiveness of myometrial cells to pro-inflammatory/pro-labor stimuli

Progesterone (P4) acting through the P4 receptor (PR) isoforms, PR-A and PR-B, promotes uterine quiescence for most of pregnancy, in part, by inhibiting the response of myometrial cells to pro-labor inflammatory stimuli. This anti-inflammatory effect is inhibited by phosphorylation of PR-A at serine-344 and -345 (pSer^344/345-PRA). Activation of the cyclic adenosine monophosphate (cAMP) signaling pathway also promotes uterine quiescence and myometrial relaxation. This study examined the cross-talk between P4/PR and cAMP signaling to exert anti-inflammatory actions and control pSer^344/345-PRA generation in myometrial cells. In the hTERT-HM^A/B immortalized human myometrial cell line P4 inhibited responsiveness to interleukin (IL)-1β and forskolin (increases cAMP) and 8-Br-cAMP increased this effect in a concentration-dependent and synergistic manner that was mediated by activation of protein kinase A (PKA). Forskolin also inhibited the generation of pSer^344/345-PRA and expression of key contraction-associated genes. Generation of pSer^344/345-PRA was catalyzed by stress-activated protein kinase/c-Jun NH₂-terminal kinase (SAPK/JNK). Forskolin inhibited pSer^344/345-PRA generation, in part, by increasing the expression of dual specificity protein phosphatase 1 (DUSP1), a phosphatase that inactivates mitogen-activated protein kinases (MAPKs) including SAPK/JNK. P4/PR and forskolin increased DUSP1 expression. The data suggest that P4/PR promotes uterine quiescence via cross-talk and synergy with cAMP/PKA signaling in myometrial cells that involves DUSP1-mediated inhibition of SAPK/JNK activation.

Mitochondrial Membrane Potential Regulates Nuclear Gene Expression in Macrophages Exposed to Prostaglandin E2

Metabolic engagement is intrinsic to immune cell function. Prostaglandin E2 (PGE2) has been shown to modulate macrophage activation, yet how PGE2 might affect metabolism is unclear. Here, we show that PGE2 caused mitochondrial membrane potential (Δψm) to dissipate in interleukin-4-activated (M(IL-4)) macrophages. Effects on Δψm were a consequence of PGE2-initiated transcriptional regulation of genes, particularly Got1, in the malate-aspartate shuttle (MAS). Reduced Δψm caused alterations in the expression of 126 voltage-regulated genes (VRGs), including those encoding resistin-like molecule α (RELMα), a key marker of M(IL-4) cells, and genes that regulate the cell cycle. The transcription factor ETS variant 1 (ETV1) played a role in the regulation of 38% of the VRGs. These results reveal ETV1 as a Δψm-sensitive transcription factor and Δψm as a mediator of mitochondrial-directed nuclear gene expression.

Isolevuglandins and cardiovascular disease

Isolevuglandins are 4-ketoaldehydes formed by peroxidation of arachidonic acid. Isolevuglandins react rapidly with primary amines including the lysyl residues of proteins to form irreversible covalent modifications. This review highlights evidence for the potential role of isolevuglandin modification in the disease processes, especially atherosclerosis, and some of the tools including small molecule dicarbonyl scavengers utilized to assess their contributions to disease.

Anti-inflammation effects of 8-oxo-9-octadecenoic acid isolated from Undaria peterseniana in lipopolysaccharide-stimulated macrophage cells

The aim of this study was to investigate the anti-inflammatory activity of 8-oxo-9-octadecenoic acid (OOA) isolated from Undaria peterseniana by examining its ability to inhibit the lipopolysaccharide (LPS)-induced production of inflammatory mediators in RAW 264.7 macrophage cells. We found that OOA significantly suppressed the LPS-induced production of nitric oxide (NO) and inflammatory cytokines. OOA downregulated the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2 proteins. With respect to proinflammatory signaling pathways, OOA inhibited LPS-induced mitogen-activated protein kinase signaling by inhibiting the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). Moreover, OOA inhibited LPS-induced nuclear factor (NF)-κB signaling by reducing the phosphorylation of IκB-α and p50 proteins. These results indicate that OOA significantly reduces proinflammatory signaling, which results in reduced expression of cytokines and proinflammatory mediators. Taken together, these results suggest that OOA has potent anti-inflammatory effects and could be considered an effective anti-inflammatory agent.

Control of cytokine mRNA degradation by the histone deacetylase inhibitor ITF2357 in rheumatoid arthritis fibroblast-like synoviocytes: beyond transcriptional regulation

BACKGROUND

Histone deacetylase inhibitors (HDACi) suppress cytokine production in immune and stromal cells of patients with rheumatoid arthritis (RA). Here, we investigated the effects of the HDACi givinostat (ITF2357) on the transcriptional and post-transcriptional regulation of inflammatory markers in RA fibroblast-like synoviocytes (FLS).

METHODS

The effects of ITF2357 on the expression and messenger RNA (mRNA) stability of IL-1β-inducible genes in FLS were analyzed using array-based qPCR and Luminex. The expression of primary and mature cytokine transcripts, the mRNA levels of tristetraprolin (TTP, or ZFP36) and other AU-rich element binding proteins (ARE-BP) and the cytokine profile of fibroblasts derived from ZFP36^+/+ and ZFP36^-/- mice was measured by qPCR. ARE-BP silencing was performed by small interfering RNA (siRNA)-mediated knockdown, and TTP post-translational modifications were analyzed by immunoblotting.

RESULTS

ITF2357 reduced the expression of 85% of the analyzed IL-1β-inducible transcripts, including cytokines (IL6, IL8), chemokines (CXCL2, CXCL5, CXCL6, CXCL10), matrix-degrading enzymes (MMP1, ADAMTS1) and other inflammatory mediators. Analyses of mRNA stability demonstrated that ITF2357 accelerates IL6, IL8, PTGS2 and CXCL2 mRNA degradation, a phenomenon associated with the enhanced transcription of TTP, but not other ARE-BP, and the altered post-translational status of TTP protein. TTP knockdown potentiated cytokine production in RA FLS and murine fibroblasts, which in the latter case was insensitive to inhibition by ITF2357 treatment.

CONCLUSIONS

Our study identifies that regulation of cytokine mRNA stability is a predominant mechanism underlying ITF2357 anti-inflammatory properties, occurring via regulation of TTP. These results highlight the therapeutic potential of ITF2357 in the treatment of RA.