Release Of Soluble Mediators Research Articles

Cholangiokines: undervalued modulators in the hepatic microenvironment.

The biliary epithelial cells, also known as cholangiocytes, line the intra- and extrahepatic bile ducts, forming a barrier between intra- and extra-ductal environments. Cholangiocytes are mostly known to modulate bile composition and transportation. In hepatobiliary diseases, bile duct injury leads to drastic alterations in cholangiocyte phenotypes and their release of soluble mediators, which can vary depending on the original insult and cellular states (quiescence, senescence, or proliferation). The cholangiocyte-secreted cytokines (also termed cholangiokines) drive ductular cell proliferation, portal inflammation and fibrosis, and carcinogenesis. Hence, despite the previous consensus that cholangiocytes are bystanders in liver diseases, their diverse secretome plays critical roles in modulating the intrahepatic microenvironment. This review summarizes recent insights into the cholangiokines under both physiological and pathological conditions, especially as they occur during liver injury-regeneration, inflammation, fibrosis and malignant transformation processes.

Clinacanthus nutans aqueous leaves extract exerts anti-allergic activity in preclinical anaphylactic models via alternative IgG pathway

Ethnopharmacological relevanceAllergy is mediated by the crosslinking of immunoglobulins (Ig) -E or -G to their respective receptors, which degranulates mast cells, macrophages, basophils, or neutrophils, releasing allergy-causing mediators. The removal of these mediators such as histamine, platelet-activating factor (PAF) and interleukins (ILs) released by effector cells will alleviate allergy. Clinacanthus nutans (C. nutans), an herbal plant in Southeast Asia, is used traditionally to treat skin rash, an allergic symptom. Previously, we have reported that C. nutans aqueous leaves extract (CNAE) was able to suppress the release of β-hexosaminidase and histamine but not interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-α) in the IgE-induced mast cell degranulation model at 5 mg/mL and above. We also found that CNAE could protect rats against ovalbumin-challenged active systemic anaphylaxis (OVA-ASA) through the downregulation and upregulation of certain metabolites using proton nuclear magnetic resonance (1H-NMR) metabolomics approach. Aim of the studyAs allergy could be mediated by both IgE and IgG, we further evaluated the anti-allergy potential of CNAE in both in vitro model of IgG-induced macrophage activation and in vivo anaphylaxis models to further dissect the mechanism of action underlying the anti-allergic properties of CNAE. Material & methodsThe anti-allergy potential of CNAE was evaluated in in vivo anaphylaxis models of ovalbumin-challenged active systemic anaphylaxis (OVA-ASA) and IgE-challenged passive systemic anaphylaxis (PSA) using Sprague Dawley rats as well as IgG-challenged passive systemic anaphylaxis (IgG-PSA) using C57BL/6 mice. Meanwhile, in vitro model of IgG-induced macrophage activation model was performed using IC-21 macrophages. The release of soluble mediators from both IgE and IgG-mediated pathways were measured using enzyme-linked immunosorbent assay (ELISA). The signaling molecules targeted by CNAE were identified by performing Western blot. ResultsIgG, platelet-activating factor (PAF) and IL-6 was suppressed by CNAE in OVA-ASA, but not IgE. In addition, CNAE significantly suppressed PAF and IL-6 in IgG-PSA but did not suppress histamine, IL-4 and leukotrienes C4 (LTC4) in IgE-PSA. CNAE also inhibited IL-6 and TNF-α by inhibiting the phosphorylation of ERK1/2 in the IgG-induced macrophage activation model. ConclusionOverall, our findings supported that CNAE exerts its anti-allergic properties by suppressing the IgG pathway and its mediators by inhibiting ERK1/2 phosphorylation, thus providing scientific evidence supporting its traditional use in managing allergy.

The role of platelet mediated thromboinflammation in acute liver injury.

Acute liver injuries have wide and varied etiologies and they occur both in patients with and without pre-existent chronic liver disease. Whilst the pathophysiological mechanisms remain distinct, both acute and acute-on-chronic liver injury is typified by deranged serum transaminase levels and if severe or persistent can result in liver failure manifest by a combination of jaundice, coagulopathy and encephalopathy. It is well established that platelets exhibit diverse functions as immune cells and are active participants in inflammation through processes including immunothrombosis or thromboinflammation. Growing evidence suggests platelets play a dualistic role in liver inflammation, shaping the immune response through direct interactions and release of soluble mediators modulating function of liver sinusoidal endothelial cells, stromal cells as well as migrating and tissue-resident leucocytes. Elucidating the pathways involved in initiation, propagation and resolution of the immune response are of interest to identify therapeutic targets. In this review the provocative role of platelets is outlined, highlighting beneficial and detrimental effects in a spatial, temporal and disease-specific manner.

Serum Soluble Mediator Profiles and Networks During Acute Infection With Distinct DENV Serotypes.

A panoramic analysis of chemokines, pro-inflammatory/regulatory cytokines, and growth factors was performed in serum samples from patients with acute DENV infection (n=317) by a high-throughput microbeads array. Most soluble mediators analyzed were increased in DENV patients regardless of the DENV serotype. The substantial increase (≥10-fold) of CXCL10, IL-6, and IFN-γ, and decreased levels of PDGF (<0.4-fold) was universally identified in all DENV serotypes. Of note, increased levels of CXCL8, CCL4, and IL-12 (≥3-9-fold) were selectively observed in DENV2 as compared to DENV1 and DENV4. Heatmap and biomarker signatures further illustrated the massive release of soluble mediators observed in DENV patients, confirming the marked increase of several soluble mediators in DENV2. Integrative correlation matrices and networks showed that DENV infection exhibited higher connectivity among soluble mediators. Of note, DENV2 displayed a more complex network, with higher connectivity involving a higher number of soluble mediators. The timeline kinetics (Day 0-1, D2, D3, D4-6) analysis additionally demonstrated differences among DENV serotypes. While DENV1 triggers a progressive increase of soluble mediators towards D3 and with a decline at D4-6, DENV2 and DENV4 develop with a progressive increase towards D4-6 with an early plateau observed in DENV4. Overall, our results provided a comprehensive overview of the immune response elicited by DENV infection, revealing that infection with distinct DENV serotypes causes distinct profiles, rhythms, and dynamic network connectivity of soluble mediators. Altogether, these findings may provide novel insights to understand the pathogenesis of acute infection with distinct DENV serotypes.

Neutrophil extracellular traps and cancer-associated thrombosis

The hypercoagulable state associated with malignancy is well described. However, the mechanisms by which tumors cause this hypercoagulable state are yet to be fully understood. This review summarizes the available literature of human and animal studies examining NETs and cancer-associated thrombosis. The methods for detecting and quantifying NET formation are growing but are not yet standardized in practice. Furthermore, it is important to distinguish between measuring neutrophil activation and NET formation, as the former can be present without the latter. Citrullination of histones by peptidylarginine deiminase 4 (PAD4) is considered one of the key pathways leading to NET formation. Cancer cells can prime neutrophils toward NET formation through the release of soluble mediators, such as interleukin-8, and activation of platelets, and may cause excess NET formation. Dismantling NETs through exogenous deoxyribonuclease has been shown to degrade NETs and reduce thrombus formation in vitro but may simultaneously release prothrombotic NET components, such as DNA and histones. Inhibiting PAD4 is far from clinical trials, but animal models show promising results with a potentially favorable safety profile. Interestingly, results from animal studies suggest that several therapies approved for other indications, such as interleukin-1 receptor blockade and JAK inhibition, may mitigate excessive NET formation or the prothrombotic effects of NETs in cancer. It is yet to be determined if inhibition of NET formation reduces cancer-associated thrombosis also in the clinical setting.

Inflammation and Cancer: From the Development of Personalized Indicators to Novel Therapeutic Strategies.

Colorectal (CRC) and hepatocellular carcinoma (HCC) are associated with chronic inflammation, which plays a role in tumor development and malignant progression. An unmet medical need in these settings is the availability of sensitive and specific noninvasive biomarkers. Their use will allow surveillance of high-risk populations, early detection, and monitoring of disease progression. Moreover, the characterization of specific fingerprints of patients with nonalcoholic fatty liver disease (NAFLD) without or with nonalcoholic steatohepatitis (NASH) at the early stages of liver fibrosis is necessary. Some lines of evidence show the contribution of platelets to intestinal and liver inflammation. Thus, low-dose Aspirin, an antiplatelet agent, reduces CRC and liver cancer incidence and mortality. Aspirin also produces antifibrotic effects in NAFLD. Activated platelets can trigger chronic inflammation and tissue fibrosis via the release of soluble mediators, such as thromboxane (TX) A2 and tumor growth factor (TGF)-β, and vesicles containing genetic material (including microRNA). These platelet-derived products contribute to cyclooxygenase (COX)-2 expression and prostaglandin (PG)E2 biosynthesis by tumor microenvironment cells, such as immune and endothelial cells and fibroblasts, alongside cancer cells. Enhanced COX-2-dependent PGE2 plays a crucial role in chronic inflammation and promotes tumor progression, angiogenesis, and metastasis. Antiplatelet agents can indirectly prevent the induction of COX-2 in target cells by inhibiting platelet activation. Differently, selective COX-2 inhibitors (coxibs) block the activity of COX-2 expressed in the tumor microenvironment and cancer cells. However, coxib chemopreventive effects are hampered by the interference with cardiovascular homeostasis via the coincident inhibition of vascular COX-2-dependent prostacyclin biosynthesis, resulting in enhanced risk of atherothrombosis. A strategy to improve anti-inflammatory agents’ use in cancer prevention could be to develop tissue-specific drug delivery systems. Platelet ability to interact with tumor cells and transfer their molecular cargo can be employed to design platelet-mediated drug delivery systems to enhance the efficacy and reduce toxicity associated with anti-inflammatory agents in these settings. Another peculiarity of platelets is their capability to uptake proteins and transcripts from the circulation. Thus, cancer patient platelets show specific proteomic and transcriptomic expression profiles that could be used as biomarkers for early cancer detection and disease monitoring.

Comprehensive Phytochemical Profiling of Polyherbal Divya-Kayakalp-Vati and Divya-Kayakalp-Oil and Their Combined Efficacy in Mouse Model of Atopic Dermatitis-Like Inflammation Through Regulation of Cytokines.

PurposeAtopic dermatitis (AD) is a chronic inflammatory disease that varies in signs and symptoms in different individuals. General symptoms include dryness of the skin, itching, and development of red to brownish-gray patches. Divya-Kayakalp-Vati (DKV) and -Oil (DKO) are Indian polyherbal compositions prescribed for treating inflammatory skin diseases. In the present study, we evaluated the anti-inflammatory efficacy of DKV and DKO co-treatment (DKV-O) in ameliorating Oxazolone (OXA)-stimulated AD-like inflammation and pro-inflammatory cytokine release in a Swiss albino mouse model.MethodsPhytochemical profiling of the DKV and DKO were done using Liquid Chromatography-Mass Spectroscopy (LC-MS) QToF. Swiss albino mice were sensitized for 7 days and treated with OXA in their ear region. Stimulated and control animals were orally treated with DKV and topically with DKO. Anti-inflammatory efficacy of DKV-O was determined in OXA-treated animals through physiological, histopathological, and biochemical parameter analysis.ResultsDKV and DKO formulations individually contained 39 and 59 phytochemicals, respectively. Many of the phytochemicals have been reported to have anti-inflammatory activities. In the OXA-sensitized Swiss albino mice, combined treatment with DKV-O, and separately with Dexamethasone (positive control) significantly reduced the OXA-stimulated ear edema, biopsy weight, and epidermal thickness. DKV-O further reduced OXA-stimulated induction of inflammatory lesions, neutrophil influx, and release of Interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and myeloperoxidase.ConclusionFinally, DKV-O co-treatment showed good pharmacological effects in ameliorating AD-like inflammation through the modulation of inflammatory cell influx and release of soluble mediators. Therefore, DKV-O treatment can be used as a suitable polyherbal therapeutic against AD-like inflammatory diseases.

Patient Heterogeneity in Acute Myeloid Leukemia: Leukemic Cell Communication by Release of Soluble Mediators and Its Effects on Mesenchymal Stem Cells.

Acute myeloid leukemia (AML) is an aggressive bone marrow malignancy, and non-leukemic stromal cells (including mesenchymal stem cells, MSCs) are involved in leukemogenesis and show AML-supporting effects. We investigated how constitutive extracellular mediator release by primary human AML cells alters proteomic profiles of normal bone marrow MSCs. An average of 6814 proteins (range 6493−6918 proteins) were quantified for 41 MSC cultures supplemented with AML-cell conditioned medium, whereas an average of 6715 proteins (range 6703−6722) were quantified for untreated control MSCs. The AML effect on global MSC proteomic profiles varied between patients. Hierarchical clustering analysis identified 10 patients (5/10 secondary AML) showing more extensive AML-effects on the MSC proteome, whereas the other 31 patients clustered together with the untreated control MSCs and showed less extensive AML-induced effects. These two patient subsets differed especially with regard to MSC levels of extracellular matrix and mitochondrial/metabolic regulatory proteins. Less than 10% of MSC proteins were significantly altered by the exposure to AML-conditioned media; 301 proteins could only be quantified after exposure to conditioned medium and 201 additional proteins were significantly altered compared with the levels in control samples (153 increased, 48 decreased). The AML-modulated MSC proteins formed several interacting networks mainly reflecting intracellular organellar structure/trafficking but also extracellular matrix/cytokine signaling, and a single small network reflecting altered DNA replication. Our results suggest that targeting of intracellular trafficking and/or intercellular communication is a possible therapeutic strategy in AML.

Dietary Fatty Acids at the Crossroad between Obesity and Colorectal Cancer: Fine Regulators of Adipose Tissue Homeostasis and Immune Response.

Colorectal cancer (CRC) is among the major threatening diseases worldwide, being the third most common cancer, and a leading cause of death, with a global incidence expected to increase in the coming years. Enhanced adiposity, particularly visceral fat, is a major risk factor for the development of several tumours, including CRC, and represents an important indicator of incidence, survival, prognosis, recurrence rates, and response to therapy. The obesity-associated low-grade chronic inflammation is thought to be a key determinant in CRC development, with the adipocytes and the adipose tissue (AT) playing a significant role in the integration of diet-related endocrine, metabolic, and inflammatory signals. Furthermore, AT infiltrating immune cells contribute to local and systemic inflammation by affecting immune and cancer cell functions through the release of soluble mediators. Among the factors introduced with diet and enriched in AT, fatty acids (FA) represent major players in inflammation and are able to deeply regulate AT homeostasis and immune cell function through gene expression regulation and by modulating the activity of several transcription factors (TF). This review summarizes human studies on the effects of dietary FA on AT homeostasis and immune cell functions, highlighting the molecular pathways and TF involved. The relevance of FA balance in linking diet, AT inflammation, and CRC is also discussed. Original and review articles were searched in PubMed without temporal limitation up to March 2021, by using fatty acid as a keyword in combination with diet, obesity, colorectal cancer, inflammation, adipose tissue, immune cells, and transcription factors.

Structure-guided design of ultrapotent disruptive IgE inhibitors to rapidly terminate acute allergic reactions

Anaphylaxis represents one of the most severe and fatal forms of allergic reactions. Like most other allergies, it is caused by activation of basophils and mast cells by allergen-mediated cross-linking of IgE bound to its high-affinity receptor, FcεRI, on the cell surface. The systemic release of soluble mediators induces an inflammatory cascade, rapidly causing symptoms with peak severity in minutes to hours after allergen exposure. Primary treatment for anaphylaxis consists of immediate intramuscular administration of adrenaline. While adrenaline alleviates life-threatening symptoms of an anaphylactic reaction, there are currently no disease-modifying interventions available. We sought to develop potent and fast-acting IgE inhibitors with the potential to rapidly terminate acute allergic reactions. Using affinity maturation by yeast display and structure-guided molecular engineering, we generated 3 optimized disruptive IgE inhibitors based on designed ankyrin repeat proteins and assessed their ability to actively remove IgE from allergic effector cells invitro as well as invivo in mice. The engineered IgE inhibitors rapidly dissociate preformed IgE:FcεRI complexes, terminate IgE-mediated signaling in preactivated human blood basophils invitro, and shut down preinitiated allergic reactions and anaphylaxis in mice invivo. Fast-acting disruptive IgE inhibitors demonstrate the feasibility of developing kinetically optimized inhibitors for the treatment of anaphylaxis and the rapid desensitization of allergic individuals.

The Neutrophil Secretome as a Crucial Link between Inflammation and Thrombosis.

Cardiovascular diseases are a leading cause of death. Blood–cell interactions and endothelial dysfunction are fundamental in thrombus formation, and so further knowledge of the pathways involved in such cellular crosstalk could lead to new therapeutical approaches. Neutrophils are secretory cells that release well-known soluble inflammatory signaling mediators and other complex cellular structures whose role is not fully understood. Studies have reported that neutrophil extracellular vesicles (EVs) and neutrophil extracellular traps (NETs) contribute to thrombosis. The objective of this review is to study the role of EVs and NETs as key factors in the transition from inflammation to thrombosis. The neutrophil secretome can promote thrombosis due to the presence of different factors in the EVs bilayer that can trigger blood clotting, and to the release of soluble mediators that induce platelet activation or aggregation. On the other hand, one of the main pathways by which NETs induce thrombosis is through the creation of a scaffold to which platelets and other blood cells adhere. In this context, platelet activation has been associated with the induction of NETs release. Hence, the structure and composition of EVs and NETs, as well as the feedback mechanism between the two processes that causes pathological thrombus formation, require exhaustive analysis to clarify their role in thrombosis.

The Extracellular Bone Marrow Microenvironment-A Proteomic Comparison of Constitutive Protein Release by In Vitro Cultured Osteoblasts and Mesenchymal Stem Cells.

Simple SummaryNormal blood cells are formed in the bone marrow by a process called hematopoiesis. This process is supported by a network of non-hematopoietic cells including connective tissue cells, blood vessel cells and bone-forming cells. However, these cells can also support the growth of cancer cells, i.e., hematological malignancies (e.g., leukemias) and cancers that arise in another organ and spread to the bone marrow. Two of these cancer-supporting normal cells are bone-forming osteoblasts and a subset of connective tissue cells called mesenchymal stem cells. One mechanism for their cancer support is the release of proteins that support cancer cell proliferation and progression of the cancer disease. Our present study shows that both these normal cells release a wide range of proteins that support cancer cells, and inhibition of this protein-mediated cancer support may become a new strategy for cancer treatment.Mesenchymal stem cells (MSCs) and osteoblasts are bone marrow stromal cells that contribute to the formation of stem cell niches and support normal hematopoiesis, leukemogenesis and development of metastases from distant cancers. This support is mediated through cell–cell contact, release of soluble mediators and formation of extracellular matrix. By using a proteomic approach, we characterized the protein release by in vitro cultured human MSCs (10 donors) and osteoblasts (nine donors). We identified 1379 molecules released by these cells, including 340 proteins belonging to the GO-term Extracellular matrix. Both cell types released a wide range of functionally heterogeneous proteins including extracellular matrix molecules (especially collagens), several enzymes and especially proteases, cytokines and soluble adhesion molecules, but also several intracellular molecules including chaperones, cytoplasmic mediators, histones and non-histone nuclear molecules. The levels of most proteins did not differ between MSCs and osteoblasts, but 82 proteins were more abundant for MSC (especially extracellular matrix proteins and proteases) and 36 proteins more abundant for osteoblasts. Finally, a large number of exosomal proteins were identified. To conclude, MSCs and osteoblasts show extracellular release of a wide range of functionally diverse proteins, including several extracellular matrix molecules known to support cancer progression (e.g., metastases from distant tumors, increased relapse risk for hematological malignancies), and the large number of identified exosomal proteins suggests that exocytosis is an important mechanism of protein release.

Role of Mitochondria in the Redox Signaling Network and Its Outcomes in High Impact Inflammatory Syndromes.

Inflammation is associated with the release of soluble mediators that drive cellular activation and migration of inflammatory leukocytes to the site of injury, together with endothelial expression of adhesion molecules, and increased vascular permeability. It is a stepwise tightly regulated process that has been evolved to cope with a wide range of different inflammatory stimuli. However, under certain physiopathological conditions, the inflammatory response overwhelms local regulatory mechanisms and leads to systemic inflammation that, in turn, might affect metabolism in distant tissues and organs. In this sense, as mitochondria are able to perceive signals of inflammation is one of the first organelles to be affected by a dysregulation in the systemic inflammatory response, it has been associated with the progression of the physiopathological mechanisms. Mitochondria are also an important source of ROS (reactive oxygen species) within most mammalian cells and are therefore highly involved in oxidative stress. ROS production might contribute to mitochondrial damage in a range of pathologies and is also important in a complex redox signaling network from the organelle to the rest of the cell. Therefore, a role for ROS generated by mitochondria in regulating inflammatory signaling was postulated and mitochondria have been implicated in multiple aspects of the inflammatory response. An inflammatory condition that affects mitochondrial function in different organs is the exposure to air particulate matter (PM). Both after acute and chronic pollutants exposure, PM uptake by alveolar macrophages have been described to induce local cell activation and recruitment, cytokine release, and pulmonary inflammation. Afterwards, inflammatory mediators have been shown to be able to reach the bloodstream and induce a systemic response that affects metabolism in distant organs different from the lung. In this proinflammatory environment, impaired mitochondrial function that leads to bioenergetic dysfunction and enhanced production of oxidants have been shown to affect tissue homeostasis and organ function. In the present review, we aim to discuss the latest insights into the cellular and molecular mechanisms that link systemic inflammation and mitochondrial dysfunction in different organs, taking the exposure to air pollutants as a case model.

Oleic acid and derivatives affect human endothelial cell mitochondrial function and vasoactive mediator production

BackgroundInhalation of common air pollutants such as diesel and biodiesel combustion products can induce vascular changes in humans which may contribute to increased mortality and morbidity associated with fine particulate matter exposures. Diesel, biodiesel, and other combustion byproducts contain fatty acid components capable of entering the body through particulate matter inhalation. Fatty acids can also be endogenously released into circulation following a systemic stress response to some inhaled pollutants such as ozone. When in the circulation, bioactive fatty acids may interact with cells lining the blood vessels, potentially inducing endothelial dysfunction. To examine whether fatty acids could potentially be involved in human vascular responses to air pollutants, we determined the effects of fatty acids and derivatives on important vascular cell functions.MethodsHuman umbilical vein endothelial cells (HUVEC) were exposed in vitro to oleic acid (OA) or OA metabolites for 4-48 h. Cytotoxicity, vasodilator production (by ELISA measurement), mitochondrial function (using Sea Horse assays), and iron metabolism (inferred by ICP-OES measurements) were examined, with standard statistical testing (ANOVA, t-tests) employed.ResultsDose-dependent cytotoxicity was noted at 24 h, with 12-hydroxy OA more potent than OA. Mitochondrial stress testing showed that 12-hydroxy OA and OA induce mitochondrial dysfunction. Analysis of soluble mediator release from HUVEC showed a dose-dependent increase in prostaglandin F2α, a lipid involved in control of vascular tone, at 24 h (85% above controls) after OA-BSA exposure. RT-PCR analysis revealed OA did not induce changes in gene expression at noncytotoxic concentrations in exposed HUVEC, but 12-OH OA did alter ICAM and COX2 gene expression.ConclusionsTogether, these data demonstrate that FA may be capable of inducing cytotoxic effects and altering expression of mediators of vascular function following inhalation exposure, and may be implicated in air pollutant-induced deaths and hospitalizations. (267 of max 350 words).

Immunomodulatory Drugs Alter the Metabolism and the Extracellular Release of Soluble Mediators by Normal Monocytes.

Immunomodulatory drugs (IMiDs) are used in the treatment of hematological malignancies, especially multiple myeloma. IMiDs have direct anticancer effects but also indirect effects via cancer-supporting stromal cells. Monocytes are a stromal cell subset whose metabolism is modulated by the microenvironment, and they communicate with neighboring cells through extracellular release of soluble mediators. Toll-like receptor 4 (TLR4) is then a common regulator of monocyte metabolism and mediator release. Our aim was to investigate IMiD effects on these two monocyte functions. We compared effects of thalidomide, lenalidomide, and pomalidomide on in vitro cultured normal monocytes. Cells were cultured in medium alone or activated by lipopolysaccharide (LPS), a TLR4 agonist. Metabolism was analyzed by the Seahorse XF 96 cell analyzer. Mediator release was measured as culture supernatant levels. TLR4 was a regulator of both monocyte metabolism and mediator release. All three IMiDs altered monocyte metabolism especially when cells were cultured with LPS; this effect was strongest for lenalidomide that increased glycolysis. Monocytes showed a broad soluble mediator release profile. IMiDs decreased TLR4-induced mediator release; this effect was stronger for pomalidomide than for lenalidomide and especially thalidomide. To conclude, IMiDs can alter the metabolism and cell–cell communication of normal monocytes, and despite their common molecular target these effects differ among various IMiDs.

Ex vivo culture of lesional psoriasis skin for pharmacological testing

BackgroundPsoriasis is a chronic, inflammatory skin disorder resulting from a complex interplay between immune and skin cells via release of soluble mediators. While a lot is known about the molecular mechanisms behind psoriasis pathogenesis, there is still a need for preclinical research models that accuratelyreplicate the disease. ObjectiveThis study aimed to develop and characterize ex vivo culture of psoriasis skin as a model for pharmacological testing, where the immunological events of psoriasis can be followed. MethodsFull thickness punch biopsies of lesional psoriasis skin were cultured in submerged conditions up to 144 h followingin situ T cell stimulation with rhIL-23 and anti-CD3 and anti-CD28 antibodies. The T cell mediated skin inflammation was assessed by gene and protein l analysis for a panel of inflammatory mediators. Tissue integrity and morphology were evaluated by histological analysis. ResultsT cell stimulation resulted in functional and psoriasis specificin situ activation of T cells. The expression levels of most of the proinflammatory mediators related to both immune and skin cells were comparable to these in freshly isolated tissue at 48 and 96 h of culture. Tissue integrity and morphology were sustained up to 96 h. Treatment with a corticosteroid reduced the expression of several pro-inflammatory cytokines and chemokines, whereas anti-IL-17A antibody treatment reduced the expression of the IL-17A downstream markers IL-8 and DEFB4. ConclusionBy preserving keyimmunopathological mechanisms of psoriasis, ex vivo culture of psoriasis skin can be used for the investigation of inflammatory processes of psoriasis and for preclinical drug discovery research.

Ethanol Induction of Innate Immune Signals Across BV2 Microglia and SH-SY5Y Neuroblastoma Involves Induction of IL-4 and IL-13.

Innate immune signaling molecules, such as Toll-like receptors (TLRs), cytokines and transcription factor NFκB, are increased in post-mortem human alcoholic brain and may play roles in alcohol dependence and neurodegeneration. Innate immune signaling involves microglia -neuronal signaling which while poorly understood, may impact learning and memory. To investigate mechanisms of ethanol induction of innate immune signaling within and between brain cells, we studied immortalized BV2 microglia and SH-SY5Y human neuroblastoma to model microglial and neuronal signaling. Cells were treated alone or in co-culture using a Transwell system, which allows transfer of soluble mediators. We determined immune signaling mRNA using real-time polymerase chain reaction. Ethanol induced innate immune genes in both BV2 and SH-SY5Y cultured alone, with co-culture altering gene expression at baseline and following ethanol exposure. Co-culture blunted ethanol-induced high mobility group box protein 1 (HMGB1)-TLR responses, corresponding with reduced ethanol induction of several proinflammatory NFκB target genes. In contrast, co-culture resulted in ethanol upregulation of cytokines IL-4 and IL-13 in BV2 and corresponding receptors, that is, IL-4 and IL-13 receptors, in SH-SY5Y, suggesting induction of a novel signaling pathway. Co-culture reduction in HMGB1-TLR levels occurs in parallel with reduced proinflammatory gene induction and increased IL-4 and IL-13 ligands and receptors. Findings from these immortalized and tumor-derived cell lines could provide insight into microglial-neuronal interactions via release of soluble mediators in vivo.

The Janus Face of Tumor Microenvironment Targeted by Immunotherapy.

The tumor microenvironment (TME) is a complex entity where host immune and non-immune cells establish a dynamic crosstalk with cancer cells. Through cell-cell interactions, which are mediated by key signals, such as the PD-1/PD-L1 axis, as well as the release of soluble mediators, this articulated process defines the nature of TME determining tumor development, prognosis, and response to therapy. Specifically, tumors are characterized by cellular plasticity that allows for the microenvironment to polarize towards inflammation or immunosuppression. Thus, the dynamic crosstalk among cancer, stromal, and immune components crucially favors the dominance of one of the Janus-faced contexture of TME crucial to the outcome of tumor development and therapeutic response. However, mostly, TME is dominated by an immunosuppressive landscape that blocks antitumor immunity and sustain tumor progression. Hence, in most cases, the immunosuppressive components of TME are highly competent in suppressing tumor-specific CD8+ T lymphocytes, the effectors of cancer destruction. In this complex context, immunotherapy aims to arm the hidden Janus face of TME disclosing and potentiating antitumor immune signals. Herein, we discuss recent knowledge on the immunosuppressive crosstalk within TME, and share perspectives on how immunotherapeutic approaches may exploit tumor immune signals to generate antitumor immunity.

Platelet-Neutrophil Crosstalk in Atherothrombosis.

Atherothrombosis is a frequent cause of cardiovascular mortality. It is mostly triggered by plaque rupture and exposure of the thrombogenic subendothelial matrix, which initiates platelet aggregation and clot formation. Current antithrombotic strategies, however, target both thrombosis and physiological hemostasis and thereby increase bleeding risk. Thus, there is an unmet clinical need for optimized therapies. Neutrophil activation and consecutive interactions of neutrophils and platelets contribute mechanistically to thromboinflammation and arterial thrombosis, and thus present a potential therapeutic target. Platelet-neutrophil interactions are mediated through adhesion molecules such as P-selectin and P-selectin glycoprotein ligand 1 as well as glycoprotein Ib and macrophage-1 antigen, which mediate physical cell interactions and intracellular signaling. Release of soluble mediators as well as direct signaling between platelets and neutrophils lead to their reciprocal activation and neutrophil release of extracellular traps, scaffolds of condensed chromatin that play a prothrombotic role in atherothrombosis. In this article, we review the role of neutrophils and neutrophil-derived prothrombotic molecules in platelet activation and atherothrombosis, and highlight potential therapeutic targets.

Platelet-Neutrophil Interplay: Insights Into Neutrophil Extracellular Trap (NET)-Driven Coagulation in Infection.

Well established for their central role in hemostasis, platelets have increasingly been appreciated as immune cells in recent years. This emerging role should not come as a surprise as the central immune cells of invertebrates, hemocytes, are able to phagocytose, secrete soluble mediators and promote coagulation of hemolymph, blurring the line between immunity and hemostasis. The undeniable evolutionary link between coagulation and immunity becomes even clearer as the role of platelets in inflammation is better understood. Platelets exert a range of immune-related functions, many of which involve an intimate interplay with leukocytes. Platelets promote leukocyte recruitment via endothelial activation and can serve as “landing pads” for leukocytes, facilitating cellular adhesion in vascular beds devoid of classic adhesion molecules. Moreover, platelets enhance leukocyte function both through direct interactions and through release of soluble mediators. Among neutrophil-platelets interactions, the modulation of neutrophil extracellular traps (NETs) is of great interest. Platelets have been shown to induce NET formation; and, in turn, NET components further regulate platelet and neutrophil function. While NETs have been shown to ensnare and kill pathogens, they also initiate coagulation via thrombin activation. In fact, increased NET formation has been associated with hypercoagulability in septic patients as well as in chronic vascular disorders. This review will delve into current knowledge of platelet-neutrophil interactions, with a focus on NET-driven coagulation, in the context of infectious diseases. A better understanding of these mechanisms will shed a light on the therapeutic potential of uncoupling immunity and coagulation through targeting of NETs.