Proteomics profiling reveals inflammatory biomarkers of antidepressant treatment response: Findings from the CO-MED trial.

Animal and human studies suggest an association between depression and aberrant immune response. Further, common inflammatory markers may change during the course of antidepressant treatment in patients. The objective of this study was to evaluate changes in inflammatory markers and clinical outcomes from subjects enrolled in the Combining Medications to Enhance Depression Outcome (CO-MED) trial. At baseline and week 12 (treatment completion), plasma samples of 102 participants were analyzed via a multiplex assay comprised of inflammatory markers using a 27-plex standard assay panel plus a 4-plex human acute phase xMAP technology based platform. We carried out analyses in two steps. First, t-tests were used to identify inflammatory marker levels that changed between baseline and week 12. For markers that were altered, logistic regression models were then conducted to look for associated changes in remission at week 12. Among the 31 inflammatory markers analyzed, several cytokines (IL-5, IFN-γ, IL-13), two chemokines (Eotaxin-1/CCL11, RANTES) and an acute-phase reactant (serum amyloid P component) showed change from baseline to week 12. However, only two indicated differential remission responses. Interestingly, increased levels of Eotaxin-1/CCL11 correlated with remission at week 12, whereas decreased levels of IFN-γ correlated with non-remission at week 12. Results suggest that these inflammatory proteins may serve as predictors of treatment response.

Changes in cytokine and chemokine expression distinguish dysthymic disorder from major depression and healthy controls.

An important area of uncertainty is the inflammatory degree to which depression occurring as part of dysthymic disorder may differ from major depression. Using a 27-plex cytokine assay, we analyzed the serum of 12 patients with dysthymic disorder, 12 with major depression, and an age-, sex-, and body mass index-matched control group of 20 healthy volunteers. We observed that patients with dysthymic disorder exhibited aberrant cytokine and chemokine expression compared with healthy controls and patients with major depression. The levels of interferon-γ-induced protein 10 highly predicted dysthymic disorder. Network analyses revealed that in patients with dysthymic disorder, the vertices were more sparsely connected and adopted a more hub-like architecture, and the connections from neighboring vertices of interleukin 2 and eotaxin-1 increased. After treatment with the same antidepressant, there was no difference between dysthymic disorder and major depression regarding any of the cytokines or chemokines analyzed. For dysthymic disorder, changes in the levels of interferon-γ-induced protein 10 and macrophage inflammatory protein-1α correlated with depression improvement. The findings suggest that the cytokine milieu in dysthymic disorder differs either at the level of individual expression or in network patterns. Moreover, chemokines play an important role in driving the pathophysiology of dysthymic disorder.

Thrombomodulin inhibits the activation of eosinophils and mast cells.

Eosinophils and mast cells play critical roles in the pathogenesis of bronchial asthma. Activation of both cells leads to the release of pro-inflammatory mediators in the airway of asthmatic patients. Recently, we have shown that inhaled thrombomodulin inhibits allergic bronchial asthma in a mouse model. In the present study, we hypothesize that thrombomodulin can inhibit the activation of eosinophils and mast cells. The effect of thrombomodulin on the activation and release of inflammatory mediators from eosinophils and mast cells was evaluated. Thrombomodulin inhibited the eotaxin-induced chemotaxis, upregulation of CD11b and degranulation of eosinophils. Treatment with thrombomodulin also significantly suppressed the degranulation and synthesis of inflammatory cytokines and chemokines in eosinophils and mast cells. Mice treated with a low-dose of inhaled thrombomodulin have decreased number of eosinophils and activated mast cells and Th2 cytokines in the lungs compared to untreated mice. The results of this study suggest that thrombomodulin may modulate allergic responses by inhibiting the activation of both eosinophils and mast cells.

Synephrine inhibits eotaxin-1 expression via the STAT6 signaling pathway.

Citrus contain various flavonoids and alkaloids that have multiple biological activities. It is known that the immature Citrus contains larger amounts of bioactive components, than do the mature plants. Although Citrus flavonoids are well known for their biological activities, Citrus alkaloids have not previously been assessed. In this study, we identified synephrine alkaloids as an active compound from immature Citrus unshiu, and investigated the effect of synephrine on eotaxin-1 expression. Eotaxin-1 is a potent chemoattractant for eosinophils, and a critical mediator, during the development of eosinophilic inflammation. We found that synephrine significantly inhibited IL-4-induced eotaxin-1 expression. This synephrine effect was mediated through the inhibition of STAT6 phosphorylation in JAK/STAT signaling. We also found that eosinophil recruitment induced by eotaxin-1 overexpression was inhibited by synephrine. Taken together, these findings indicate that inhibiting IL-4-induced eotaxin-1 expression by synephrine occurs primarily through the suppression of eosinophil recruitment, which is mediated by inhibiting STAT6 phosphorylation.

Dietary fish oil reduces the acute inflammatory response and enhances resolution of antigen-induced peritonitis.

Dietary n-3 polyunsaturated fatty acids (PUFA) influence the inductive phase of inflammation but less is known about their effects on the resolution phase. This study examined the effects of dietary fish oil on induction and resolution of antigen-induced inflammation in mice. Mice were fed a control diet with or without 2.8% fish oil, immunized twice with methylated BSA (mBSA) and inflammation induced by intraperitoneal injection of mBSA. Prior to and at different time points after mBSA administration, peritoneal cells were analyzed and expression of surface molecules determined by flow cytometry. Concentration of chemokines, cytokines and soluble cytokine receptors was determined by ELISA. Mice fed the fish oil diet had fewer peritoneal neutrophils, shorter resolution interval and lower levels of pro-inflammatory cytokines and chemokines than mice fed the control diet. In mice fed the fish oil diet there was an early peak in peritoneal levels of the immunosuppressive molecules sIL-6R and TGF-ß, that was not seen in mice fed the control diet. In the resolution phase, peritoneal macrophages from mice fed the fish oil diet expressed more of the atypical chemokine receptor D6 and peritoneal TGF-ß levels were higher than that in mice fed the control diet. Furthermore, in the late-resolution phase there were more peritoneal eosinophils and macrophages in mice fed the fish oil diet than in mice fed the control diet. These results demonstrate a suppressive effect of n-3 PUFA on the inductive phase of inflammation and indicate an enhancing effect of n-3 PUFA on resolution of inflammation.

Activation of innate immunity accelerates sialoadenitis in a mouse model for Sjögren's syndrome-like disease.

OBJECTIVE: Sjögren's syndrome is a chronic autoimmune disorder characterized by progressive lymphocytic infiltration within the salivary and lacrimal glands. This study was undertaken to investigate the effects of innate immunity activation on sialoadenitis in a mouse strain genetically susceptible for development of SS-like disease. METHODS: Female New Zealand Black X New Zealand White F1 mice were repeatedly treated with toll-like 3 receptor agonist poly(I:C). Submandibular glands were investigated at different time points for sialoadenitis by immunohistochemistry and for gene expression of different chemokines by quantitative PCR. Submandibular gland-infiltrating cells were characterized by flow cytometry. RESULTS: Poly(I:C) treatment significantly upregulated the expression of multiple chemokines within the submandibular glands. The severity and incidence of sialoadenitis was considerably higher in poly(I:C)-treated mice. There was a preponderance of dendritic cells and NK cells in the initial inflammatory cell infiltrates, and these were followed by CD4+ T cells. CONCLUSIONS: Our data clearly demonstrate that systemic activation of innate immunity accelerates sialoadenitis in a mouse model for SS-like disease. These findings suggest that chronic activation of innate immunity can influence certain features of SS.

The effects of PG102, a water-soluble extract from Actinidia arguta, on serum total IgE levels: a double-blind, randomized, placebo-controlled exploratory clinical study.

BACKGROUND: Recent studies have reported that blocking IgE has a potentially beneficial role in the treatment of various allergic diseases. Previously, we found that PG102, a water-soluble extract prepared from the edible fruits of Actinidia arguta, can effectively reduce IgE levels using murine models. AIMS: To evaluate the efficacy of PG102 at lowering levels of total IgE in asymptomatic subjects with atopy. METHODS: A total of 90 asymptomatic subjects with atopy were randomized equally to a PG102 group or a placebo control group and treated for 8 weeks in a double-blind manner. Total serum IgE, eosinophilic cation protein (ECP), eotaxin, thymus, and activation-regulated chemokine (TARC), IL-4, IL-5, and IL-13 levels were measured. Eosinophil counts were determined before and after treatment, and results were compared. In addition, possible adverse reactions were thoroughly checked in this first human trial. RESULTS: Levels of total IgE significantly increased in the control group but showed no change in the PG102 group, and change differences between the control and PG102 groups were significant (+12.9%, vs.-5.7%, p = 0.015). Levels of ECP and eotaxin and eosinophil counts produced similar results. However, the other variables showed no significant changes after treatment. CONCLUSION: In this exploratory clinical trial, it was found that 8 weeks of treatment with PG102 effectively reduced the levels of total IgE in apparently asymptomatic subjects with atopy.

RANTES expression induced by Toll-like receptor 4 ligand in rat airway smooth muscle cells.

Airway smooth muscle cells (ASMCs) have been reported to express Toll-like receptors (TLRs) and take part in the pathogenesis of asthma exacerbation. Though TLRs were found to activate epidermal growth factor receptor (EGFR) in airway epithelial cells, little is known about the association of TLR ligands with EGFR signaling pathways in ASMCs. Using primary cultured ASMCs from Brown Norway rats, TLR4, eotaxin, and RANTES mRNA were examined by real-time quantitative RT-PCR after stimulation with the TLR4 ligand, lipopolysaccharides (LPS). The concentration of RANTES protein in culture supernatant was measured by ELISA. The effect of EGFR signaling inhibitors on RANTES expression was examined as well. Phosphorylation of EGFR after stimulation was examined by Western Blotting. Rat ASMCs expressed TLR4 and eotaxin, and LPS upregulated RANTES production. The EGFR tyrosine kinase inhibitor AG1478, the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, and the matrix metalloproteinase (MMP) inhibitor GM6001 inhibited RANTES expression induced by LPS. LPS phosphorylated EGFR. TLR4 activation can induce RANTES expression via EGFR transactivation and PI3K/Akt pathway in rat ASMCs. MMP-induced EGFR proligand cleavage and ligand binding to EGFR seem to be involved in this pathway. These findings may be critical in the pathogenesis of asthma exacerbation by airway infection.

Heparin and structurally related polymers attenuate eotaxin-1 (CCL11) release from human airway smooth muscle.

BACKGROUND AND PURPOSE: The glycosaminoglycan heparin has anti-inflammatory activity and is exclusively found in mast cells, which are localized within airway smooth muscle (ASM) bundles of asthmatic airways. Interleukin (IL)-13 induces the production of multiple inflammatory mediators from ASM including the eosinophil chemoattractant chemokine, eotaxin-1. Heparin and related glycosaminoglycan polymers having structurally heterogeneous polysaccharide side chains that varied in molecular weight, sulphation and anionic charge were used to identify features of the heparin molecule linked to anti-inflammatory activity. EXPERIMENTAL APPROACH: Cultured human ASM cells were stimulated with interleukin (IL)-13 in the absence or presence of heparin and related polymers. Eotaxin-1 was quantified using chemokine antibody arrays and ELISA. KEY RESULTS: Unfractionated heparin attenuated IL-13-dependent eotaxin-1 production and this effect was reproduced with low molecular weight heparins (3 and 6 kDa), demonstrating a minimum activity fragment of at least 3 kDa. N-desulphated, 20% re-N-acetylated heparin (anticoagulant) was ineffective against IL-13-dependent eotaxin-1 production compared with 90% re-N-acetylated (anticoagulant) or O-desulphated (non-anticoagulant) heparin, suggesting a requirement for N-sulphation independent of anticoagulant activity. Other sulphated molecules with variable anionic charge and molecular weight exceeding 3 kDa (dextran sulphate, fucoidan, chondroitin sulphate B) inhibited IL-13-stimulated eotaxin-1 release to varying degrees. However, non-sulphated dextran had no effect. CONCLUSIONS: Inhibition of IL-13-dependent eotaxin-1 release by heparin involved but did not depend upon sulphation, though loss of N-sulphation reduced the attenuating activity, which could be restored by N-acetylation. This anti-inflammatory effect was also partially dependent on anionic charge, but independent of molecular size above 3 kDa and the anticoagulant action of heparin.

[Role of eotaxin in the pathophysiology of asthma]. / Rola eotaksyn w patofizjologii astmy.

Asthma is associated with eosinophilic airway inflammation and eosinophils are believed to be important in the pathogenesis of asthma. IL-5 has been considered the central mediator for eosinophilic proliferation, differentiation and eosinophilic inflammation, but results of recent studies suggest that besides IL-5, eotaxin may contribute to the pathogenesis of asthma. Eotaxin is CC chemokine first isolated from guinea pig bronchoalveolar lavage. It selectively binds to a specific receptor (CCR3) highly expressed on eosinophils, basophils, and mast cells being important in the pathogenesis of asthma. Eotaxin is produced mainly by epithelial cells of lung and gut, to mediate organ preferential attraction of eosinophils. Production of eotaxin is stimulated by IL-4, IL-13, TNF(-alpha). Human eotaxin family includes: eotaxin-1 (CCL11), eotaxin-2 (CCL24) and eotaxin-3 (CCL26). It seems that eotaxin-3 may be expressed following allergen challenge. Studies with glucocorticosteroids have shown some inhibitory effect on eotaxin production in cell culture in vitro however, very little in vivo data exists in humans relating to corticosteroid effects on chemokine levels. CCR3 receptor is considered as the possible therapeutic target in asthma treatment.