Release Of Proinflammatory Chemokines Research Articles

Immunomodulatory effect of Mesenchymal stem cells: A blessing to combat cytokine storm appeared during COVID-19 infection

Whilst the manufacture of a safe and potent vaccine for SARS-CoV-2 is the ultimate goal of the COVID-19 response, research is also in progress to develop novel treatments that could facilitate infected patients in the meantime. Casualty in COVID-19 patients are connected with onset of acute respiratory distress syndrome (ARDS) due to its cytokine storm phenomenon resulting in abandoned systemic inflammatory response from the release of pro-inflammatory chemokines (CCL2, CCL3, CCL5, CXCL8, CXCL9, CXCL-10) and cytokines (TNF-α, TGF-β, IFN-α, IFNγ, IL-1β, IL-6, IL-12, IL-8, IL-33). This implies immune system is not capable to turn itself off once it has generated enough of a defense against the virus. An extended cytokine storm will finally shut down breathing completely, which may lead to death. In the context of COVID19, there is a likelihood possibility of treatment of patients by transplanting Mesenchymal Stem Cells (MSCs). MSCs are known to have an immune-regulatory role and MSCs have used in patients that have been affected by the cytokine storm may fine balance the immune system in order to stop the overreaction, without switching it completely off, so that the immune system can carry on to fight the infection. In this review, we have considered the research studies which have used MSCs for the treatment of COVID-19. The cohort study is needed to approve MSCs as therapy, although many clinical trials have been registered to apply MSCs as therapy for severely affected COVID-19 patients.

Anti-Inflammatory and Antiatopic Effects of Rorippa cantoniensis (Lour.) Ohwi in RAW 264.7 and HaCaT Cells.

This study evaluated the effects of Rorippa cantoniensis (Lour.) ohwi extract (RCE) on factors associated with inflammation-related skin lesions in RAW 264.7 and HaCaT cells. RCE inhibited the levels of proinflammatory mediators and cytokines such as nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-6, and tumor necrosis factor (TNF)-α in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. In addition, RCE significantly inhibited the expression of chemokines and cytokines such as MDC/CCL22, TARC/CCL17, RANTES/CCL5, CTSS, IL-6, IL-1β, and TNF-α in HaCaT cells costimulated by TNF-α and interferon (IFN)-γ in a concentration-dependent manner. These results suggest that RCE attenuated the TNF-α- and IFN-γ-induced release of proinflammatory chemokines and cytokines probably by suppressing the activation of MAPK (JNK and p38), NF-κB, and STAT1 signaling. Moreover, RCE significantly increased the expression of skin components such as hyaluronic acid and aquaporin, which play important roles in the physical and chemical barriers of the skin. These results suggest that RCE has significant anti-inflammatory and antiatopic activities, which may be beneficial for the topical treatment of inflammatory skin disorders.

Characterization of a Novel Anti-inflammatory Biogenic Amine

Abstract Tryptophan (Trp) is an essential amino acid whose catabolism generates a cascade of over fifty molecules in a cell-specific manner. Three major Trp metabolic pathways have been described: synthesis of serotonin, synthesis of melatonin and generation of kynurenines. In mammalian cells, 90% of Trp is processed through the kynurenine pathway and kynurenine metabolites are regarded as one of the most powerful mechanism for immune regulation. We recently reported a novel biogenic amine, 3HKA, generated through a still uncharacterized lateral pathway of Trp catabolism. This novel biogenic amine is generated by both professional (Dendritic Cells) and non-professional (Lymphatic Endothelial Cells) antigen presenting cells and, differently from all others Trp metabolites, display unique “in vivo” immunosuppressive capabilities. In vitro, 3-HKA exhibited an anti-inflammatory profile by inhibiting the IFN-g-mediated STAT1/NF-kB pathway in both mouse and human dendritic cells (DCs) with a consequent decrease in the release of pro-inflammatory chemokines and cytokines; most notably, TNFa, IL-6, and IL12p70. In vivo, 3-HKA exerted protective effects in an experimental mouse model of Psoriasis by decreasing skin thickness, erythema, scaling and fissuring, reducing TNFa, IL-1b, IFN-g, and IL-17 production, and inhibiting generation of effector CD8+ T cells. Similarly, in a mouse model of nephrotoxic nephritis, besides reducing inflammatory cytokines, 3-HKA improved proteinuria and serum urea nitrogen, overall ameliorating the immune-mediated glomerulonephritis and renal dysfunction. Overall we propose that this novel biological amine is a crucial component of Trp-mediated immune tolerance.

3-hydroxy-L-kynurenamine is an immunomodulatory biogenic amine

Tryptophan catabolism is a major metabolic pathway utilized by several professional and non-professional antigen presenting cells to maintain immunological tolerance. Here we report that 3-hydroxy-l-kynurenamine (3-HKA) is a biogenic amine produced via an alternative pathway of tryptophan metabolism. In vitro, 3-HKA has an anti-inflammatory profile by inhibiting the IFN-γ mediated STAT1/NF-κΒ pathway in both mouse and human dendritic cells (DCs) with a consequent decrease in the release of pro-inflammatory chemokines and cytokines, most notably TNF, IL-6, and IL12p70. 3-HKA has protective effects in an experimental mouse model of psoriasis by decreasing skin thickness, erythema, scaling and fissuring, reducing TNF, IL-1β, IFN-γ, and IL-17 production, and inhibiting generation of effector CD8+ T cells. Similarly, in a mouse model of nephrotoxic nephritis, besides reducing inflammatory cytokines, 3-HKA improves proteinuria and serum urea nitrogen, overall ameliorating immune-mediated glomerulonephritis and renal dysfunction. Overall, we propose that this biogenic amine is a crucial component of tryptophan-mediated immune tolerance.

SGLT-2 (Sodium-Glucose Cotransporter 2) Inhibition Reduces Ang II (Angiotensin II)-Induced Dissecting Abdominal Aortic Aneurysm in ApoE (Apolipoprotein E) Knockout Mice.

Abdominal aortic aneurysm (AAA) is a pathological condition of permanent vessel dilatation that predisposes to the potentially fatal consequence of aortic rupture. SGLT-2 (sodium-glucose cotransporter 2) inhibitors have emerged as powerful pharmacological tools for type 2 diabetes mellitus treatment. Beyond their glucose-lowering effects, recent studies have shown that SGLT-2 inhibitors reduce cardiovascular events and have beneficial effects on several vascular diseases such as atherosclerosis; however, the potential effects of SGLT-2 inhibition on AAA remain unknown. This study evaluates the effect of oral chronic treatment with empagliflozin-an SGLT-2 inhibitor-on dissecting AAA induced by Ang II (angiotensin II) infusion in apoE (apolipoprotein E)-/- mice. Approach and Results: Empagliflozin treatment significantly reduced the Ang II-induced increase in maximal suprarenal aortic diameter in apoE-/- mice independently of blood pressure effects. Immunohistochemistry analysis revealed that empagliflozin diminished Ang II-induced elastin degradation, neovessel formation, and macrophage infiltration at the AAA lesion. Furthermore, Ang II infusion resulted in a marked increase in the expression of chemokines (CCL-2 [chemokine (C-C motif) ligand 2] and CCL-5 [chemokine (C-C motif) ligand 5]), VEGF (vascular endothelial growth factor), and MMP (matrix metalloproteinase)-2 and MMP-9 in suprarenal aortic walls of apoE-/- mice, and all were reduced by empagliflozin cotreatment. Western blot analysis revealed that p38 MAPK (p38 mitogen-activated protein kinase) and NF-κB (nuclear factor-κB) activation was also reduced in the suprarenal aortas of apoE-/- mice cotreated with empagliflozin. Finally, in vitro studies in human aortic endothelial cells and macrophages showed that empagliflozin inhibited leukocyte-endothelial cell interactions and release of proinflammatory chemokines. Pharmacological inhibition of SGLT-2 by empagliflozin inhibits AAA formation. SGLT-2 inhibition might represent a novel promising therapeutic strategy to prevent AAA progression.

Synergistic interactions of chamomile flower, myrrh and coffee charcoal in inhibiting pro-inflammatory chemokine release from activated human macrophages

Abstract Background The herbal medicinal product Myrrhinil-Intest®, a combination of myrrh, chamomile flower extract and coffee charcoal is used for the maintenance therapy of inflammatory bowel disease. In vitro studies revealed that the herbal components influence chemokine signaling of human macrophages as part of an anti-inflammatory mechanism. However, the occurrence of synergistic effects remains unexplored. Aim The present study aims to investigate the synergistic effect of dual combinations of the plant extracts on the pro-inflammatory chemokine (CXCL13) release from activated human macrophages. Methods The single effect of myrrh, chamomile flower and coffee charcoal extract on CXCL13 release from lipopolysaccharide stimulated human macrophages was investigated using ELISA and IC50 values were determined. Budesonide served as positive control. To characterize the combined effect, IC50 values were used to prepare combinations of two plant extracts in different proportions to each other (3:5; 1:1; 5:3). Interpretation of the data was based on isobologram analysis and calculation of a combination index (CI). Results LPS-induced CXCL13 release from human macrophages was inhibited after treatment with myrrh (IC50 = 19 μg/ml), chamomile flower (IC50 = 82 μg/ml) and coffee charcoal (IC50 = 106 μg/ml) whereby the extent of inhibition was comparable to budesonide. All combinations of two plant extracts resulted in synergistic effects with varying magnitude (CI from 0.82 to 0.42). The combination of myrrh and coffee charcoal (ratio of 3:5) exhibited the strongest synergistic effect (CI = 0.42). Increasing amounts of coffee charcoal resulted in increased synergistic activity. Conclusion Synergistic effects between all plant components contribute to the anti-inflammatory activity of all dual combinations of the plant components and support the composition of the herbal combination.

Idelalisib Impairs TREM-1 and TLR Mediated Neutrophil Activation

Introduction: Polymorphonuclear neutrophils (PMN) play an essential role in innate inflammatory processes. Their functions are strictly regulated and many activating / inhibiting mechanisms along with their pathways are only incompletely understood. Besides toll-like receptors (TLR) and NOD-like receptors (NLR), triggering receptor expressed on myeloid cells (TREM)-1 is implicated in innate immune activation of these cells and plays a role in infectious as well as non-infectious conditions. Activation of TREM-1 results in release of pro-inflammatory chemokines and cytokines, increased surface expression of cell activation markers and degranulation. In TREM-1 downstream pathways and regulation of TREM-1 expression protein kinase A (PKA), phosphatidylinositide 3-kinase (PI3K), mitogen-activated protein kinases (p38 MAPK) and phospholipase C (PLC) are involved.During the last years, pharmacological development of small-molecule inhibitors for target therapy of hematological and oncological disease led to approval of different new drugs. Idelalisib, which is approved for B-cell malignancies functions as a selective PI3Kδ inhibitor and current data suggest that it influences innate immune defense. This may create a new high-risk group of patients vulnerable for severe infections when monitoring only for quantitative counts (as in neutropenia) but not for qualitative PMN functions.Methods: Idelalisib (Selleckchem) as a selective PI3Kδ inhibitor was used to get deeper insights in the involvement of PI3K in TREM-1 signaling in vitro. Therefore PMN from healthy humans were isolated by dextran sedimentation and Histopaque centrifugation and pretreated with idelalisib. Cells were activated with anti-TREM-1 agonistic antibody (6B1), isotope antibody (4C9) (both own production), lipopolysaccharide (LPS) or zymosan and effector functions like phagocytosis, L-selectin shedding, degranulation and oxidative burst were carried out by flow cytometry and kinetics in a fluorescence reader respectively. Interleukin 8 secretion was detected by ELISA (R&D), for apoptosis and viability Nicoletti staining and MTT assays were performed. Signal transduction pathways were evaluated by Western blot analysis of phosphorylated and non-phosphorylated molecules. For in vivo studies similarly, blood samples of patients receiving idelalisib treatment were followed up for PMN functions as described above to investigate immunomudulatory effects of this selective PI3Kδ inhibitor.Results: PMN of healthy human donors revealed functional deficiencies after pretreatment with idelalisib. We observed highly impaired oxidative burst, impaired phagocytosis, degranulation (reduced CD66b and CD11b surface expression) and L-selectin shedding (elevated CD62L surface expression) after cell activation by TREM-1 ligation as well as after activation with LPS. Cells liberated reduced amounts of IL-8, while apoptosis and viability remained nearly unchanged. Furthermore, we evaluated essential signaling molecules of the TREM-1 and TLR cascade in idelalisib-treated PMN by Western blot analysis.In vivo studies aimed to elucidate if this plays a relevant clinical role in immune responses of patients receiving idelalisib treatment by following up data and blood samples of patients receiving this therapy. Similarly, we observed impaired PMN functions, although the cells were preactivated to a much higher extend.Conclusion: So far these results provide a deeper understanding of innate immune response concerning TREM-1 signaling in PMN. By connecting the experimental data of functional impaired PMN after idelalisib pretreatment to the clinical aspects of patients receiving therapy with this small-molecule inhibitor we aim to highlight the clinical relevance of impaired PMN functions caused by new drugs, resulting in functional deficiencies but normal cell counts. In the future this may contribute to improved medical care for this patients by probably providing them with extended (prophylactic) anti-infective therapies. DisclosuresHess:Celgene: Honoraria; Pfizer: Honoraria; Roche: Honoraria; Novartis: Honoraria; Janssen: Honoraria; Roche, CTI, Pfizer, Celgene: Research Funding.

Silencing of Tumor Necrosis Factor Receptor-1 in Human Lung Microvascular Endothelial Cells Using Particle Platforms for siRNA Delivery.

Acute lung injury (ALI) and its most severe manifestation, acute respiratory distress syndrome (ARDS), is a clinical syndrome defined by acute hypoxemic respiratory failure and bilateral pulmonary infiltrates consistent with edema. In-hospital mortality is 38.5% for AL, and 41.1% for ARDS. Activation of alveolar macrophages in the donor lung causes the release of pro-inflammatory chemokines and cytokines, such as TNF-α. To determine the relevance of TNF-α in disrupting bronchial endothelial cell function, we stimulated human THP-1 macrophages with lipopolysaccharide (LPS) and used the resulting cytokine-supplemented media to disrupt normal endothelial cell functions. Endothelial tube formation was disrupted in the presence of LPS-activated THP- 1 conditioned media, with reversal of the effect occurring in the presence of 0.1µg/ml Enbrel, indicating that TNF-α was the major serum component inhibiting endothelial tube formation. To facilitate lung conditioning, we tested liposomal and porous silicon (pSi) delivery systems for their ability to selectively silence TNFR1 using siRNA technology. Of the three types of liposomes tested, only cationic liposomes had substantial endothelial uptake, with human cells taking up 10-fold more liposomes than their pig counterparts; however, non-specific cellular activation prohibited their use as immunosuppressive agents. On the other hand, pSi microparticles enabled the accumulation of large amounts of siRNA in endothelial cells compared to standard transfection with Lipofectamine(®) LTX, in the absence of non-specific activation of endothelia. Silencing of TNFR1 decreased TNF-α mediated inhibition of endothelial tube formation, as well as TNF-α-induced upregulation of ICAM-1, VCAM, and E-selection in human lung microvascular endothelial cells.

Metabotropic glutamate receptor 5 modulates calcium oscillation and innate immune response induced by lipopolysaccharide in microglial cell

Microglia, the primary immune cells in the brain, have been implicated as the predominant cells governing inflammation-mediated neuronal damage. In response to immunological challenges such as lipopolysaccharide (LPS), microglia are activated and subsequently inflammatory process is initiated as evidenced by the release of pro-inflammatory chemokines and cytokines. Here we show that Group I metabotropic glutamate receptor 5 (mGluR5) is involved in LPS-induced microglia activation. LPS triggered a similar pattern of [Ca2+]i oscillation in N9, Toll-like receptor 4 (TLR4)-mutant EOC 20, TLR4-wild-type and TLR4-deficient primary mouse microglia, suggesting that LPS-induced [Ca2+]i oscillation is independent of TLR4. The characteristics of [Ca2+]i oscillation induced by LPS are consistent with those observed in mGluR5 activation. In addition, mGluR5 antagonist 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) abolished LPS-induced [Ca2+]i oscillation. Immunocytochemistry demonstrated that LPS colocalizes with mGluR5 in microglia and the direct binding of LPS and mGluR5 was further validated by antibody-based fluorescence resonance energy transfer (FRET) technology. Activation of mGluR5 using a selective agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) significantly expanded LPS-induced nuclear factor-kappa B (NF-κB) activity and CHPG alone increased NF-κB activity as well. But, mGluR5 antagonist MTEP attenuated the actions of LPS, CHPG and the additive effect of LPS and CHPG in microglia. LPS induced tumor necrosis factor-α (TNF-α) secretion in N9 microglia, but not in TLR4-mutant EOC 20 and TLR4-deficient primary mouse microglia. CHPG reduced LPS-caused TNF-α production, but MTEP increased LPS-induced TNF-α production and blocked the effect of CHPG in N9 microglia. These data demonstrate that mGluR5 and TLR4 are two critical receptors that mediate microglia activation in response to LPS, suggesting that mGluR5 may represent a novel target for modulating microglia-dependent neuroinflammation.

Human Cord Blood-Derived Mast Cells Are Activated by the Nod1 Agonist M-TriDAP to Release Pro-Inflammatory Cytokines and Chemokines

Mast cells are among the first cells of our immune system to encounter exogenous danger. Intracellular receptors such as nucleotide-binding oligomerization domain (Nod) play an important role in responding to invading pathogens. Here, we have investigated the response of human mast cells to the Nod1 ligand M-TriDAP. Human cord blood-derived mast cells (CBMCs) were activated with M-TriDAP alone, or in combination with the Toll-like receptor (TLR) ligands lipopolysaccharide (LPS) and zymosan. Release of pro-inflammatory chemokines and cytokines was measured by ELISA, cytometric bead array and LUMINEX, and degranulation was evaluated by analysis of histamine release. M-TriDAP induced a dose-dependent release of IL-8, MIP-1α, MIP-1β and TNF. In contrast, degranulation could not be observed. When cells were treated with M-TriDAP in combination with the TLR4 agonist LPS, but not with TLR2 agonist zymosan, the secretion of cytokines was augmented. We here present results demonstrating that human CBMCs are stimulated by the Nod1 agonist M-TriDAP alone and in combination with LPS to produce pro-inflammatory cytokines and chemokines. Our results add to the concept that mast cells constitute an important part of our host defense, as they are equipped with several types of important pattern recognition receptors, including TLRs and Nod.

Release of pro-inflammatory chemokines from model intestinal epithelia is inhibited by lipoxin A4 analogs

Release of pro-inflammatory chemokines from model intestinal epithelia is inhibited by lipoxin A4 analogs