AT-RvD1 modulates CCL-2 and CXCL-8 production and NF-κB, STAT-6, SOCS1, and SOCS3 expression on bronchial epithelial cells stimulated with IL-4

Effects of combination of Cryptococcus gattii and IFN-γ, IL-4 or IL-27 on human bronchial epithelial cells

BACKGROUND

Airway epithelial cells are crucial for the establishment of cryptococcosis. In experimental cryptococcosis, the Th2 immune response is associated with host susceptibility, while Th1 cells are associated with protection. The absence of IL-27 receptor alpha in mice favor the increase Cryptococcus neoformans burden in the lung. Here, we evaluated the effects of the combination of IL-4, IFN-γ or IL-27 with C. gattii on human bronchial epithelial cells (BEAS-2B).

METHODS

BEAS-2B were stimulated with IL-4, IFN-γ or IL-27 (100 ng/mL) and/or live yeast forms of C. gattii (multiplicities of infection (MOI) of 1-100) and vice-versa, as well as with heat-killed cells of C. gattii for 24 h.

RESULTS

None of the C. gattii MOIs had cytotoxic effects on BEAS-2B when compared to control. The cells stimulated by cytokines (IL-4, IFN-γ or IL-27) followed by live yeast forms of C. gattii (MOI of 100) infection and vice-versa demonstrated a reduction in IL-6, IL-8 and/or CCL2 production and activation of STAT6 (induced by IL-4) and STAT1 (induced by IL-27 or IFN-γ) when compared to cells stimulated with C. gattii, IL-4, IFN-γ or IL-27. In the combination of cytokines and heat-killed cells of C. gattii, no inhibition of these inflammatory parameters was observed. The growth of C. gattii was increased while the phagocytosis of live yeast forms of C. gattii in the BEAS-2B were reduced in the presence of IL-4, IFN-γ or IL-27. Conclusion The association of live yeast forms, but not heat-killed yeast forms, of C. gattii with IL-4, IFN-γ or IL-27 induced an anti-inflammatory effect.

The role of Resolvin D1 in liver diseases

The liver is a parenchymatous organ closely related to immunity, detoxification and metabolism of the three major nutrients. The inflammatory response is a protective mechanism of the body to eliminate harmful stimuli. However, continuous inflammatory stimulation leads to occurrence of many liver diseases and brings great social burden. Resolvin D1, a member of the specialized pro-resolving lipid mediators family, exerts anti-inflammatory, anti-oxidant stress, anti-fibrosis, anti-apoptotic, and anti-tumor effects by binding to ALX/FPR2 or GPR32. RvD1 plays an important role and has great therapeutic potential in liver diseases, which has been validated in multiple models of preclinical disease. This review will provide a detailed summary of the role of RvD1 in different liver diseases, including acute liver injury, liver ischemia/reperfusion injury, non-alcoholic fatty liver disease, liver fibrosis, and liver cancer, so as to help people have a more comprehensive understanding of RvD1 and promote its further research.

Cryptococcus neoformans in Association with Dermatophagoides pteronyssinus has Pro- (IL-6/STAT3 Overproduction) and Anti-inflammatory (CCL2/ERK1/2 Downregulation) Effects on Human Bronchial Epithelial Cells

Cryptococcosis (caused, for example, by Cryptococcus neoformans) and allergic asthma (caused, for example, by Dermatophagoides pteronyssinus) target the respiratory tract (the lung and bronchial epithelium). C. neoformans and D. pteronyssinus can coexist in the same indoor environment, and exposure to both can cause alterations in the local airway inflammatory milieu and exacerbation of airway inflammatory diseases. Here, we evaluated the effects of the association between C. neoformans and D. pteronyssinus in the modulation of airway inflammatory responses in an in vitro experimental model using human bronchial epithelial cells. BEAS-2B cells were cultivated and stimulated with D. pteronyssinus (10 μg/mL) and/or C. neoformans (MOI 100) for 24 h. No cytotoxic effect was observed in cells stimulated by C. neoformans and/or D. pteronyssinus. The production of IL-8, IL-6, and/or CCL2, but not IL-10, as well as the activation of NF-kB, STAT3, STAT6, and/or ERK1/2 were increased in cells stimulated by C. neoformans or D. pteronyssinus compared to controls. C. neoformans in association with D. pteronyssinus inhibited the CCL2‑ERK1/2 signaling pathway in cells treated with both pathogens compared to cells stimulated by D. pteronyssinus alone. In addition, their association induced an additive effect on the IL-6/STAT3 signaling pathway in cells compared to cells stimulated with D. pteronyssinus or C. neoformans only. D. pteronyssinus increased the internalization and growth of C. neoformans in BEAS-2B cells. D. pteronyssinus in association with C. neoformans promoted pro- and anti-inflammatory responses, which can modulate cryptococcal infection and asthmaticus status.

Anti-inflammatory actions of aspirin-triggered resolvin D1 (AT-RvD1) in bronchial epithelial cells infected with Cryptococcus neoformans

BACKGROUND

The interaction of Cryptococcus neoformans with airway epithelial cells is crucial for the establishment of cryptococcosis. Aspirin-triggered-resolvin D1 (AT-RvD1) is a lipid mediator produced during the resolution of inflammation and demonstrates anti-inflammatory and pro-resolution effects in several inflammatory experimental models including in the airways.

METHOD

Here, we evaluated the effects of AT-RvD1 (1, 10 or 100 nM) on human bronchial epithelial cells (BEAS-2B) stimulated with C. neoformans (1, 10 or 100 multiplicities of infection; MOI).

RESULTS

After 24 h, C. neoformans (all MOI) demonstrated no cytotoxic effects and increased IL-8 production on BEAS-2B cells when compared to controls. In addition, C. neoformans (MOI 100) increased the concentration of IL-6, but not of IL-10. AT-RvD1 (100 nM) significantly reduced the concentration of IL-8 and IL-6 and increased IL-10 production in C. neoformans-stimulated BEAS-2B cells. C. neoformans increased the phosphorylation of NF-κB and ERK1/2, and ALX/FPR2 expression. AT-RvD1 reduced the activation of NF-kB without altering the ERK1/2 and ALX/FPR2 expression. The anti-inflammatory effects of AT-RvD1 were dependent on the ALX/FPR2, once its antagonist (BOC2) reversed its anti-inflammatory effects. No alteration on the fungal burden as well as interactions with BEAS-2B cells was observed by AT-RvD1.

CONCLUSION

AT-RvD1 demonstrated significant anti-inflammatory effects in bronchial epithelial cells infected with C. neoformans without affecting the development of C. neoformans infection in the airways.

TRIAL REGISTRATION

Not applicable.

Effects of cigarette smoke extract on bronchial epithelial cells stimulated with Cryptococcus neoformans

In the airways, the adhesion of Cryptococcus neoformans with airway epithelial cells is crucial for the establishment of cryptococcosis. Tobacco smoke is considered a risk factor for cryptococcosis. Here, we evaluated the effects of cigarette smoke extract (CSE) on human bronchial epithelial cells (BEAS-2B) stimulated with C. neoformans. Multiplicities of infection (MOIs) of 1-100 of C. neoformans per cell led to increased IL-8 production and no cytotoxic effects when compared to those of controls. C. neoformans (MOI 100) also significantly increased the concentration of IL-6. In cells stimulated with CSE doses (1.0, 2.5 and 5.0%) from one or five cigarettes, increased IL-1β production was observed only in doses from one (1.0%) and five (2.5%) cigarettes when compared to that of controls. However, only 1.0% CSE failed to show cytotoxic effects. In addition, CSE significantly increased the concentration of IL-8. Cells stimulated with both CSE and C. neoformans demonstrated a reduction in IL-6/STAT3 signalling compared to that in cells stimulated by C. neoformans. In addition, a significant increase in IL-10 production was also observed. No alterations in NF-kB or ICAM-1 expression were observed among the groups. The combination of CSE and C. neoformans favoured the increase of fungal numbers and extracellular adhering of C. neoformans on BEAS-2B cells. In addition, the internalization of C. neoformans on BEAS-2B cells was reduced after CSE stimulation. In conclusion, the association of CSE and C. neoformans induced an anti-inflammatory effect in bronchial epithelial cells, which might favour the development of C. neoformans infection in the airways.

Receptors for pro-resolving mediators as a therapeutic tool for smooth muscle remodeling-associated disorders

Respiratory airway, blood vessel and intestinal wall remodeling, in which smooth muscle remodeling plays a major role, is a key pathological event underlying the development of several associated diseases, including asthma, cardiovascular disorders (e.g., atherosclerosis, hypertension, and aneurism formation), and inflammatory bowel disease. However, the mechanisms underlying these remodeling processes remain poorly understood. We hypothesize that the creation of chronic inflammation-mediated networks that support and exacerbate the airway, as well as vascular and intestinal wall remodeling, is a crucial pathogenic mechanism governing the development of the associated diseases. The failed inflammation resolution might be one of the causal pathogenic mechanisms. Hence, it is reasonable to assume that applying specialized, pro-resolving mediators (SPMs), acting via cognate G-protein coupled receptors (GPCRs), could potentially be an effective pathway for treating these disorders. However, several obstacles, such as poor understanding of the SPM/receptor signaling pathways, SMP rapid inactivation as well as their complex and costly synthesis, limit their translational potential. In this connection, stable, small-molecule SPM mimetics and receptor agonists have emerged as new, potentially suitable drugs. It has been recently shown in preclinical studies that they can effectively attenuate the manifestations of asthma, atherosclerosis and Crohn's disease. Remarkably, some biased SPM receptor agonists, which cause a signaling response in the desired inflammation pro-resolving direction, revealed similar beneficial effects. These encouraging observations suggest that SPM mimetics and receptor agonists can be applied as a novel approach for the treatment of various chronic inflammation conditions, including airway, vascular and intestinal wall remodeling-associated disorders.

IL-27 regulates IL-4-induced chemokine production in human bronchial epithelial cells

IL-4 coordinates the Th2-type immune response in inflammatory diseases such as asthma. IL-27 can inhibit the development of both Th2 and Th1 cells. However, IL-27 can also drive naïve T cells to differentiate toward the Th1 phenotype. In this study, we investigated the effects of IL-27 on the activation of IL-4-induced human bronchial epithelial cells (BEAS-2B). Compared to controls, both IL-4 and IL-27 (25-100 ng/mL) increased the concentrations of CCL2 and IL-8 in a dose-dependent manner. However, compared to cells stimulated individually with IL-4 or IL-27, treatment with a combination of both cytokines reduced CCL2 and IL-8 concentrations in a dose- and time-dependent manner. IL-4 increased the activation of p38 MAPK, ERK1/2, STAT6 and NF-κB, while IL-27 increased the activation of p38 MAPK and ERK1/2 but not STAT6 and NF-κB. Compared to IL-4-stimulated cells, cells treated with both IL-27 and IL-4 displayed decreased activation of STAT6 and NF-κB but not ERK1/2 and p38 MAPK. Taken together, these results suggest that IL-27 plays a pro-inflammatory role when administered alone but downregulates bronchial epithelial cell activation when combined with IL-4. Therefore, IL-27 may be an interesting target for the treatment of Th2 inflammatory diseases.

Agaphelin modulates the activation of human bronchial epithelial cells induced by lipopolysaccharide and IL-4

Sand fly saliva presents molecules with potential to development of compounds for treatment of inflammatory diseases. Agaphelin, isolated from the saliva of the mosquito Anopheles gambiae, demonstrates anti-inflammatory properties such as neutrophils chemotaxis inhibition. Here, we extend these results and evaluated the role of agaphelin (0.1-100 nM) in an in vitro model consisting in the activation of human bronchial epithelial cells (BEAS-2B) by IL-4 (50 ng/mL) or lipopolysaccharide (LPS; 10 ng/mL). Agaphelin is non-cytotoxic for BEAS-2B cells. Notably, agaphelin markedly reduces CCL2 and IL-8 production induced by IL-4 or LPS, without altering the IL-10 production. The TLR4 expression and STAT1 phosphorylation induced by LPS were inhibited by agaphlin. In addition, agaphelin decreased the phosphorylation of STAT6 induce by IL-4, whose effect was independent of IL-4-binding activity. Taken together, these findings identify agaphelin as a potential anti-inflammatory therapeutic agent for airway inflammations.

Resident alveolar macrophage-derived vesicular SOCS3 dampens allergic airway inflammation

Resident alveolar macrophages (AMs) suppress allergic inflammation in murine asthma models. Previously we reported that resident AMs can blunt inflammatory signaling in alveolar epithelial cells (ECs) by transcellular delivery of suppressor of cytokine signaling 3 (SOCS3) within extracellular vesicles (EVs). Here we examined the role of vesicular SOCS3 secretion as a mechanism by which AMs restrain allergic inflammatory responses in airway ECs. Bronchoalveolar lavage fluid (BALF) levels of SOCS3 were reduced in asthmatics and in allergen-challenged mice. Ex vivo SOCS3 secretion was reduced in AMs from challenged mice and this defect was mimicked by exposing normal AMs to cytokines associated with allergic inflammation. Both AM-derived EVs and synthetic SOCS3 liposomes inhibited the activation of STAT3 and STAT6 as well as cytokine gene expression in ECs challenged with IL-4/IL-13 and house dust mite (HDM) extract. This suppressive effect of EVs was lost when they were obtained from AMs exposed to allergic inflammation-associated cytokines. Finally, inflammatory cell recruitment and cytokine generation in the lungs of OVA-challenged mice were attenuated by intrapulmonary pretreatment with SOCS3 liposomes. Overall, AM secretion of SOCS3 within EVs serves as a brake on airway EC responses during allergic inflammation, but is impaired in asthma. Synthetic liposomes encapsulating SOCS3 can rescue this defect and may serve as a framework for novel therapeutic approaches targeting airway inflammation.

Sonic hedgehog (Shh) and CC chemokine ligand 2 signaling pathways in asthma

Asthma is a chronic inflammatory disease of the airways in which many cells are involved, including mast cells, eosinophils, T lymphocytes, and so on. During the process, many chemokines and mediators are released to engage in recruiting and activating eosinophils and other inflammatory cells. Also, some signaling pathways are involved in the pathobiology of asthma. Sonic hedgehog (Shh) is one of the members of hedgehog gene families. Shh signaling plays a critical role in the embryonic development, including the lung. Previous findings from our team reveal that Shh is involved in the asthma pathogenesis. Recombinant Shh could induce the CC chemokine ligand 2 (CCL2) overexpressing and Smo inhibitor GDC-O449 could inhibit CCL2 expression in airway epithelial cells, monocytes, or macrophages. Hence, we reviewed the effects of Shh and CCL2 signaling pathways, and the interaction between signaling pathways in asthma.

The G-Protein-Coupled Receptor ALX/Fpr2 Regulates Adaptive Immune Responses in Mouse Submandibular Glands

Lipoxin receptor (ALX)/N-formyl peptide receptor (FPR)-2 is a G-protein-coupled receptor that has multiple binding partners, including the endogenous lipid mediators resolvin D1, lipoxin A₄, and the Ca²⁺-dependent phospholipid-binding protein annexin A1. Previous studies have demonstrated that resolvin D1 activates ALX/Fpr2 to resolve salivary gland inflammation in the NOD/ShiLtJ mouse model of Sjögren syndrome. Moreover, mice lacking the ALX/Fpr2 display an exacerbated salivary gland inflammation in response to lipopolysaccharide. Additionally, activation of ALX/Fpr2 has been shown to be important for regulating antibody production in B cells. These previous studies indicate that ALX/Fpr2 promotes resolution of salivary gland inflammation while modulating adaptive immunity, suggesting the need for investigation of the role of ALX/Fpr2 in regulating antibody production and secretory function in mouse salivary glands. Our results indicate that aging female knockout mice lacking ALX/Fpr2 display a significant reduction in saliva flow rates and weight loss, an increased expression of autoimmune-associated genes, an up-regulation of autoantibody production, and increased CD20-positive B-cell population. Although not all effects were noted among the male knockout mice, the results nonetheless indicate that ALX/Fpr2 is clearly involved in the adaptive immunity and secretory function in salivary glands, with further investigation warranted to determine the cause(s) of these between-sex differences.

miR-122-SOCS1-JAK2 axis regulates allergic inflammation and allergic inflammation-promoted cellular interactions

The regulatory role of suppressor of cytokine signaling 1 (SOCS1) in inflammation has been reported. However, its role in allergic inflammation has not been previously reported. SOCS1 mediated in vitro and in vivo allergic inflammation. Histone deacetylase-3 (HDAC3), a mediator of allergic inflammation, interacted with SOCS1, and miR-384 inhibitor, a positive regulator of HDAC3, induced features of allergic inflammation in an SOCS1-dependent manner. miRNA array analysis showed that the expression of miR-122 was decreased by antigen-stimulation. TargetScan analysis predicted the binding of miR-122 to the 3′-UTR of SOCS1. miR-122 inhibitor induced in vitro and in vivo allergic features in SOCS1-dependent manner. SOCS1 was necessary for allergic inflammation-promoted enhanced tumorigenic and metastatic potential of cancer cells. SOCS1 and miR-122 regulated cellular interactions involving cancer cells, mast cells and macrophages during allergic inflammation. SOCS1 mimetic peptide, D-T-H-F-R-T-F-R-S-H-S-D-Y-R-R-I, inhibited in vitro and in vivo allergic inflammation, allergic inflammation-promoted enhanced tumorigenic and metastatic potential of cancer cells, and cellular interactions during allergic inflammation. Janus kinase 2 (JAK2) exhibited binding to SOCS1 mimetic peptide and mediated allergic inflammation. Transforming growth factor- Δ1 (TGF-Δ1) was decreased during allergic inflammation and showed an anti-allergic effect. SOCS1 and JAK2 regulated the production of anti-allergic TGF-Δ1. Taken together, our results show that miR-122-SOCS1 feedback loop can be employed as a target for the development of anti-allergic and anti-cancer drugs.

Bronchoprotective mechanisms for specialized pro-resolving mediators in the resolution of lung inflammation

Bronchi are exposed daily to irritants, microbes and allergens as well as extremes of temperature and acid. The airway mucosal epithelium plays a pivotal role as a sentinel, releasing alarmins when danger is encountered. To maintain homeostasis, an elaborate counter-regulatory network of signals and cellular effector mechanisms are needed. Specialized pro-resolving mediators (SPMs) are chemical mediators that enact resolution programs in response to injury, infection or allergy. SPMs are enzymatically derived from essential polyunsaturated fatty acids with potent cell-type specific immunoresolvent properties. SPMs signal by engaging cell-based receptors to turn off acute inflammatory responses and restore tissue homeostasis. Several common lung diseases involving the airways, including asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF), are characterized by unresolved bronchial inflammation. In preclinical murine models of lung disease, SPMs carry potent bronchoprotective actions. Here, we review cellular and molecular effects for SPM-initiated catabasis in the lung and their human translation.

The anti-inflammatory and pro-resolution effects of aspirin-triggered RvD1 (AT-RvD1) on peripheral blood mononuclear cells from patients with severe asthma

Asthma is an inflammatory disease that is characterized by a predominance of eosinophils and/or neutrophils in the airways. In the resolution of inflammation, lipid mediators such as resolvin D1 (RvD1) and its epimer aspirin-triggered RvD1 (AT-RvD1) are produced and demonstrate anti-inflammatory and pro-resolution effects. In experimental models such as airway allergic inflammation induced by ovalbumin in mice, RvD1 and AT-RvD1 alleviate some of the most important phenotypes of asthma. Here, we demonstrated the effects of AT-RvD1 on peripheral blood mononuclear cells (PBMCs) from healthy individuals and patients with severe asthma stimulated with lipopolysaccharide (LPS) or Dermatophagoides pteronyssinus (DM). AT-RvD1 (100nM) reduced the concentration of TNF-α in PBMCs from healthy individuals and patients with severe asthma stimulated with LPS or DM. In addition, AT-RvD1 lowered the production of IL-10 only in PBMCs from patients with severe asthma stimulated with LPS. These effects were associated in part with decreasing NF-κB activation. Moreover, AT-RvD1 significantly increased phagocytosis of apoptotic neutrophils by monocytes from patients with severe asthma. In conclusion, AT-RvD1 demonstrated both anti-inflammatory and pro-resolution effects in PBMCs from patients with severe asthma and could become in the future an alternative treatment for asthma.