Di(2-ethylhexyl) phthalate mediates IL-33 production via aryl hydrocarbon receptor and is associated with childhood allergy development.

Background: Few studies assess cord blood biomarkers to predict prenatal exposure to di(2-ethylhexyl) phthalate (DEHP) on the development of allergic diseases later in childhood. IL-33 has been indicated to play an important role in allergic diseases. We evaluated the association of prenatal DEHP exposure and IL-33 in cord blood on the development of allergic diseases. We also investigated the mechanism of DEHP in human lung epithelial cells and asthma animal models. Methods: 66 pregnant women were recruited, and their children followed when they were aged 3 years. Maternal urinary DEHP metabolites were determined using liquid chromatography-electrospray-ionization-tandem mass spectrometry. The effect of DEHP on IL-33 production was investigated in human lung epithelial cells and club cell-specific aryl hydrocarbon receptor (AhR) deficiency mice. ELISA and RT-PCR, respectively, measured the IL-33 cytokine concentration and mRNA expression. Results: The concentrations of maternal urinary DEHP metabolites and serum IL-33 in cord blood with childhood allergy were significantly higher than those in the non-childhood allergy group. DEHP and MEHP could induce IL-33 production and reverse by AhR antagonist and flavonoids in vitro. Enhanced ovalbumin-induced IL-4 and IL-33 production in bronchoalveolar lavage fluid (BALF) by DEHP exposure and suppressed in club cell-specific AhR null mice. Kaempferol has significantly reversed the DEHP effect in the asthma animal model. Conclusions: Cord blood IL-33 level was correlated to childhood allergy and associated with maternal DEHP exposure. IL-33 might be a potential target to assess the development of DEHP-related childhood allergic disease. Flavonoids might be the natural antidotes for DEHP.

Altered Pattern of Macrophage Polarization as a Biomarker for Severity of Childhood Asthma.

PURPOSE: Asthma causes a substantial morbidity and mortality burden in children and the pathogenesis of childhood asthma is not completely understood. Macrophages are heterogeneous with divergent M1/M2 polarization phenotypes in response to various stimulations during the inflammatory process. We aimed to investigate the pattern of macrophage polarization and its association with severity and exacerbation in asthmatic children. PATIENTS AND METHODS: Normal and asthmatic children aged 4-18 years were enrolled for 12 months. Children with asthma were further subgrouped according to their severity and the requirement for hospitalization during exacerbations. Clinical data were obtained from medical records. Peripheral blood samples were collected to analyze macrophage polarization, including M1, M2, and subsets, by flow cytometry. RESULTS: Fifty-one asthmatic cases and 27 normal controls were included in this study. The level of PM-2K+CD14+ but not PM-2K+CD14- was decreased in asthmatic children. The levels of M2a (CCR7-CXCR1+), M2b (CCR7-CD86+), and M2c (CCR7-CCR2+) subsets, but not M1 (CCR7+CD86+), were increased in asthmatic children. The levels of M1 were decreased, but the levels of M2c were increased, in children with moderate asthma compared to those with mild asthma. The levels of PM-2K+CD14+ cells and M1 subsets were decreased, but the M2c subset cells were increased in asthmatic children requiring hospitalization during exacerbations. CONCLUSION: Macrophage polarization may be involved in the pathogenesis of childhood asthma and is a potential biomarker of childhood asthma disease severity.

Immunological map in COVID-19.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by SARS-CoV-2, a newly discovered coronavirus that exhibits many similarities with the severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses (SARS-CoV and MERS-CoV, respectively). The definite pathogenesis and immunological influences of SARS-CoV-2 have not been fully elucidated. Therefore, we constructed a brief summary comparison of SARS-CoV-2, SARS-CoV, and MERS-CoV infections regarding their immunological changes. In addition, we further investigated the immunological differences between severe and nonsevere COVID-19 cases, and we searched for possible immunological predictors of the patient outcome by reviewing case series studies to date. Possible immunological predictors of a poor outcome are leukocytosis, neutrophilia, lymphopenia (both CD4 and CD8 T cells), an increased neutrophil-to-lymphocyte ratio (NLR), and increased levels of pro-inflammatory cytokines (IL-6 and TNF-α), Th1 cytokines (IL-2 and IFN-γ), regulatory T cell cytokines (IL-10) and Th17 cytokines (IL-17). A more precise immunological map needs to be established, which may assist in diagnosing this disease and facilitate immunological precision medicine treatment.

High-protein supplementation facilitates weight training-induced bone mineralization in baseball players.

OBJECTIVES: The aim of this study was to determine whether weight training combined with high-protein intake enhances total and regional bone mineral density (BMD) in athletes. METHODS: BMD of 27 Division 1 collegiate baseball players 18 to 22 y of age (N = 13, 2 dropouts) received either 14% protein or isocaloric 44% protein supplements and were assessed by dual-energy x-ray absorptiometry before and after a 12-wk weight training program (challenging upper and lower body). RESULTS: Baseline data showed unequivocally greater humerus BMD in the dominant arm than their contralateral non-dominant arm (∼20 %) among all baseball players. Humerus BMD of the non-dominant arm was enhanced by 2.7% after weight training for both low- and high-protein groups (main effect, P = 0.008), concurrent with an unexpected small decrease in total body BMD (main effect, P = 0.014). Humerus BMD of the dominant arm with greater baseline value than the non-dominant arm was not increased unless high protein was supplemented (+2.7 %; P < 0.05). CONCLUSION: Bones with relatively higher BMD show blunt adaptation against training, which can be relieved by high-protein supplementation. Total BMD of athletes cannot be further elevated by weight training.

Antibiotic exposure and asthma development in children with allergic rhinitis.

PURPOSE: Early-life antibiotic use may be associated with asthma, yet whether this association also exists in patients with allergic rhinitis (AR) remains unknown. We investigated the association between antibiotic exposure and asthma development in AR children. METHODS: AR patients less than 18 year-old were enrolled from the Taiwan National Health Insurance Database, which reported information from 2005 to 2010. The case group was defined as having newly developed asthma, and the control group was defined as never having an asthma diagnosis. The age of first exposure to antibiotic prescriptions and antibiotic exposure records preceding 5 years before the first asthma diagnosis were obtained from drug prescription records. The odds ratio (OR) was examined after adjusting for age, gender, resident urbanization, underlying medical disorders and medications. RESULTS: A total of 3236 AR patients with newly developed asthma and 9708 AR patients without asthma were included in this study. Antibiotic exposure before the age of 3 years was not associated with asthma development. Preceding 5-year antibiotic exposure increased the risk of asthma development with a dose-response relationship, even for antibiotics with low cumulative defined daily doses (adjusted OR 1.40, 95% CI 1.12-1.75). Preceding 5-year exposure to penicillin and macrolide significantly increased the risk of asthma when diagnosed before age 12 in AR patients, but this was not statistically significant when asthma diagnosed after age 12. CONCLUSION: Preceding 5-year antibiotic exposure, particularly to penicillin group of amoxicillin and macrolides, is associated with the risk of asthma development before age 12 in AR children.

Azithromycin suppresses Th1- and Th2-related chemokines IP-10/MDC in human monocytic cell line.

BACKGROUND: Cytokines and chemokines play critical roles in the pathogenesis of asthma. Azithromycin, a macrolides, is frequently used in asthmatic children with lower respiratory tract infection and is reported having anti-inflammatory and immunomodulatory effects. However, the effects of azithromycin on the expression of TNF-α, Th1- and Th2-related chemokines, and neutrophil chemoattractant are unknown. We investigated the in vitro effects of azithromycin on the expression of TNF-α, Th1-related chemokine interferon-γ-inducible protein-10 (IP-10/CXCL10), Th2-related chemokine macrophage-derived chemokine (MDC/CCL22) and neutrophil chemoattractant growth-related oncogene-α (GRO-α/CXCL1) in THP-1 cells as a model for human monocytes. METHODS: THP-1 cells were pretreated with various concentrations of azithromycin before Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS) stimulation. TNF-α, IP-10, MDC and GRO-α were measured by ELISA. Intracellular signaling was investigated by pathway inhibitors and Western blot. RESULT: Azithromycin suppressed MDC and IP-10 expression in LPS-stimulated THP-1 cells. However, azithromycin had no effect LPS-induced TNF-α and GRO-α expression. Western blotting revealed that azithromycin suppressed LPS-induced phosphorylation of mitogen-activated protein kinase (MAPK)-JNK and ERK expression, and also suppressed LPS-induced phosphorylation of nuclear factor (NF) κB-p65 expression. CONCLUSION: Azithromycin suppressed LPS-induced MDC expression via the MAPK-JNK and the NFκB-p65 pathway. Azithromycin also suppressed LPS-induced IP-10 via the MAPK-JNK/ERK and the NFκB-p65 pathway. Azithromycin may benefit asthmatic patients by suppressing chemokines expression.

The effects of acarbose on chemokine and cytokine production in human monocytic THP-1 cells.

BACKGROUND AND OBJECTIVES: Chronic inflammation induced by proinflammatory cytokines and chemokines is postulated to be involved in insulin resistance and ß-cell dysfunction in type 2 diabetes mellitus (T2DM). Acarbose, the α-glucosidase inhibitor, is an oral antidiabetic drug for T2DM. Acarbose suppresses inflammatory cytokine production in patients with T2DM, though the underlying mechanisms are unclear. In the present study, we aimed to investigate the anti-inflammatory effects and the exact mechanisms of acarbose in human monocytic THP-1 cells. METHODS: THP-1 cells were pretreated with acarbose and then stimulated with lipopolysaccharide (LPS). The levels of Th1-related chemokines, including interferon-γ-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), Th2-related chemokine macrophage-derived chemokine (MDC), and proinflammatory cytokine tumor necrosis factor-α (TNF-α), were determined by enzyme-linked immunosorbent assay. Intracellular signaling pathways were explored by Western blot analysis and using a chromatin immunoprecipitation assay. RESULTS: Acarbose suppressed the levels of IP-10, MCP-1, MDC, and TNF-α and downregulated phosphorylation of p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and nuclear factor-kappa B-p65 (NF-κB-p65) in LPS-stimulated THP-1 cells. Acarbose suppressed LPS-induced acetylation of histones H3 (H3) and H4 in the IP-10 and MCP-1 promoter regions. These findings revealed the suppressive effects of acarbose on IP-10, MCP-1, MDC, and TNF-α production in THP-1 cells via, at least partially, the p38, JNK, ERK, and NF-κB-p65 pathways, as well as through epigenetic regulation via histone H3 and H4 acetylation. CONCLUSION: Our study points to the therapeutic anti-inflammatory potential of acarbose.

M2 macrophage subset decrement is an indicator of bleeding tendency in pediatric dengue disease.

BACKGROUND/PURPOSE: Dengue disease is widespread in tropical and sub-tropical regions. Severe dengue infection is characterized by plasma leakage, fluid accumulation, severe bleeding, or vital organ impairment. Bleeding is a critical complication of dengue disease. However, the biomarkers of dengue disease are still unknown. Macrophages have a distinct polarization phenotype related to M1/M2 classification. Macrophage polarization toward the pro-inflammatory M1 phenotype is considered critical for efficient antiviral immune responses, whereas the anti-inflammatory M2 phenotype is considered essential for tissue remodeling. We investigated macrophage polarization patterns in the peripheral blood of pediatric patients with dengue disease. METHODS: Medical records and laboratory data were collected from 23 pediatric healthy controls and 100 dengue disease samples from 50 dengue patients. Macrophage polarization-related surface markers were assessed using flow cytometry. RESULTS: The percentage of macrophages in the peripheral blood was higher in dengue patients than in the healthy controls. The percentages of M2a and M2c macrophage subsets were higher and the percentage of M1 macrophage subset was lower in dengue patients than in healthy controls. However, the percentages of M1, M2a and M2b macrophage subsets in dengue patients with bleeding tendency were lower than that without bleeding tendency. The percentages of M2a, M2b, and M2c macrophage subsets were positively correlated with platelet counts. CONCLUSION: Decreased the percentages of M2 macrophage subsets in pediatric dengue patients are associated with bleeding tendency and lower platelet counts.

Suppressive effects of metformin on T-helper 1-related chemokines expression in the human monocytic leukemia cell line THP-1.

PURPOSE OF THE STUDY: Type 1 and type 2 diabetes mellitus (DM) are chronic T-cell-mediated inflammatory diseases. Metformin is a widely used drug for type 2 DM that reduces the need for insulin in type 1 DM. However, whether metformin has an anti-inflammatory effect for treating DM is unknown. We investigated the anti-inflammatory mechanism of metformin in the human monocytic leukemia cell line THP-1. MATERIALS AND METHODS: The human monocytic leukemia cell line THP-1 was pretreated with metformin and stimulated with lipopolysaccharide (LPS). The production of T-helper (Th)-1-related chemokines including interferon-γ-induced protein-10 (IP-10) and monocyte chemoattractant protein-1 (MCP-1), Th2-related chemokine macrophage-derived chemokine, and the proinflammatory chemokine tumor necrosis factor-α was measured using enzyme-linked immunosorbent assay. Intracellular signaling pathways were investigated using Western blot analysis and chromatin immunoprecipitation assay. RESULTS: Metformin suppressed LPS-induced IP-10 and MCP-1 production as well as LPS-induced phosphorylation of c-Jun N-terminal kinase (JNK), p38, extracellular signal-regulated kinase (ERK), and nuclear factor-kappa B (NF-κB). Moreover, metformin suppressed LPS-induced acetylation of histones H3 and H4 at the IP-10 promoter. CONCLUSIONS: Metformin suppressed the production of Th1-related chemokines IP-10 and MCP-1 in THP-1 cells. Suppressive effects of metformin on IP-10 production might be attributed at least partially to the JNK, p38, ERK, and NF-κB pathways as well as to epigenetic regulation through the acetylation of histones H3 and H4. These results indicated the therapeutic anti-inflammatory potential of metformin.

Altered pattern of monocyte differentiation and monocyte-derived TGF-ß1 in severe asthma.

CD14+ monocytes contain precursors for macrophages and fibrocytes, known to be involved in regulating airway remodeling in human asthma and distinguishable by the PM-2K marker. We sought to identify circulating subsets of PM-2K+ macrophage-like cells and evaluate their relationships to lung function, severity and control status. Circulating PM-2K+ macrophage-like cells and fibrocytes could be identified and distinguished between normal individuals (N = 152) and asthmatic subjects (N = 133) using multi-parametric flow cytometry. PM-2K+ macrophage-like cells were found to be significantly lower in asthmatic subjects, particularly noted for the CD14-PM-2K+ subset and PM-2K+CCR7-CD86+ cells in subjects with poor lung function (FEV%/FVC% < 80%) as compared to those of normal subjects and asthmatics with normal lung function, whereas the frequency of fibrocytes was higher in asthmatics and the CCR7-CD86+ subset distribution was significantly different in subjects with varying severity. Moreover, exogenous transforming growth factor beta 1 (TGF-ß1) was found to inhibit the generation of PM-2K+ macrophage-like cells, but promote the growth of fibrocytes, from CD14+ monocytes, and monocyte-derived TGF-ß1 was found to correlate with the lung function, severity and control status in asthmatic patients. Collectively, aberrant differentiation of monocytes into PM-2K+ macrophage-like cell subsets and fibrocytes, together with increased monocyte-derived TGF-ß1, characterized patients with severe asthma.

Effects of montelukast on M2-related cytokine and chemokine in M2 macrophages.

BACKGROUND/PURPOSE: Asthma is a chronic airway inflammatory disease mediated by T-helper (Th)2 cells. Montelukast (trade name Singulair) is a cysteinyl leukotriene receptor antagonist used for asthma treatment. Mirroring Th1-Th2 polarization, two distinct states of macrophages have been recognized: the classically activated (M1) macrophages and the alternatively activated (M2) macrophages. M2 polarization is known to be a response to the Th2 cytokines; however, the effects of montelukast on M2 macrophages have not been well characterized. The aim of the present study was to investigate the effects of montelukast on the expression of cytokines and chemokines in M2-like macrophages, and to explore possible intracellular signaling pathways. METHODS: The human monocytic leukemia cell line THP-1 and human monocytes from healthy donors were cultured with interleukin-4 for M2 polarization, and then the cells were pretreated with or without montelukast before lipopolysaccharide (LPS) stimulation. Supernatants were collected to determine interleukin-10, I-309/CCL1, and MDC/CCL22 levels by enzyme-linked immunosorbent assay. Intracellular signaling was investigated using nuclear factor (NF)-κB inhibitors, mitogen-activated protein kinase (MAPK) inhibitors, and western blot analysis. RESULTS: LPS-induced interleukin-10 and I-309/CCL1 expression was significantly suppressed by montelukast in THP-1-derived and human monocyte-derived M2 macrophages after LPS stimulation. MDC/CCL22 expression was only significantly suppressed by montelukast in THP-1-derived M2 macrophages after 48 hours of incubation. In western blot analysis, montelukast was able to suppress LPS-induced MAPK-phospho-p38 and NF-κB-phospho-p65 expression. CONCLUSION: Montelukast suppressed LPS-induced M2-related cytokines and chemokines in alternatively activated macrophages, and the effects might be mediated through the MAPK-p38 and NF-κB-p65 pathways.

Long-acting ß2-adrenoreceptor agonists suppress type 1 interferon expression in human plasmacytoid dendritic cells via epigenetic regulation.

The combination of inhaled long-acting ß2-adrenoreceptor (LABA) and inhaled glucocorticoid (ICS) is a major therapy for asthma. However, the increased risk of infection is still a concern. Plasmacytoid dendritic cells (pDCs) are the predominant cells producing type 1 interferon (IFN) against infection. The effect of LABA/ICS on type 1 IFN expression in human pDCs is unknown. Circulating pDCs were isolated from healthy human subjects and were pretreated with glucocorticoid (GCS), LABA or a cAMP analog, and were stimulated with Toll-like receptor (TLR) agonist CpG (TLR9) or imiquimod (TLR7) in the presence of IL-3. The expression of type 1 IFN (IFN-α/ß) were measured by ELISA. The mechanisms were investigated using receptor antagonists, pathway inhibitors, Western blotting and chromatin immunoprecipitation. GCS suppressed TLR-induced IFN-α expression, and LABA enhanced the suppressive effect. LABA alone also suppressed TLR-induced IFN-α/ß expression, and the effect was reversed by the ß2-adrenoreceptor antagonist ICI118551. Dibutyryl-cAMP, a cAMP analog, conferred a similar suppressive effect, and the effect was abrogated by the exchange protein directly activated by cAMP (Epac) inhibitor HJC0197 or intracellular free Ca2+ chelator BAPTA-AM. Formoterol suppressed TLR-induced phosphorylation of mitogen-activated protein kinase (MAPK)-p38/ERK. Formoterol suppressed interferon regulatory factor (IRF)-3/IRF-7 expression. Formoterol suppressed CpG-induced translocation of H3K4 specific methyltransferase WDR5 and suppressed H3K4 trimethylation in the IFNA and IFNB gene promoter region. LABA suppressed TLR7/9-induced type 1 IFNs production, at least partly, via the ß2-adrenoreceptor-cAMP-Epac-Ca2+, IRF-3/IRF-7, the MAPK-p38/ERK pathway, and epigenetic regulation by suppressing histone H3K4 trimethylation through inhibiting the translocation of WDR5 from cytoplasm to nucleus. LABA may interfere with anti-viral immunity.

The effects of asthma medications on reactive oxygen species production in human monocytes.

OBJECTIVE: Asthma is a chronic inflammatory airway disease induced by many environmental factors. The inhalation of allergens and pollutants promotes the production of reactive oxygen species (ROS) leading to airway inflammation, hyper-responsiveness, and remodeling in allergic asthma. The effects of asthma medications on ROS production are unclear. The present study investigated the anti-ROS effects of current asthma medications including inhaled corticosteroid (ICS; budesonide and fluticasone), leukotriene receptor antagonist (LTRA; montelukast), long-acting ß2 agonists (LABAs; salmeterol and formoterol), and a new extra-LABA (indacaterol). METHODS: The human monocyte cell line THP-1 cells were pre-treated with different concentrations of the asthma medications at different time points after hydrogen peroxide (H2O2) stimulation. H2O2 production was measured with DCFH-DA by flow cytometry. RESULTS: Montelukast, fluticasone, and salmeterol suppressed H2O2-induced ROS production. Indacaterol enhanced H2O2-induced ROS production. Budesonide and formoterol alone had no anti-ROS effects, but the combination of these two drugs significantly suppressed H2O2-induced ROS production. CONCLUSIONS: Different asthma medications have different anti-ROS effects on monocytes. The combination therapy with LABA and ICS seemed not to be the only choice for asthma control. Montelukast may also be a good supplemental treatment for the poorly controlled asthma because of its powerful anti-ROS effects. Our findings provide a novel therapeutic view in asthma.

Tumor necrosis factor-alpha inhibitors suppress CCL2 chemokine in monocytes via epigenetic modification.

The treatment of rheumatoid arthritis (RA) with tumor necrosis factor-alpha (TNF-α) inhibitors could lead to adverse effects. Therefore, the identification of downstream therapeutic targets is important. Monocyte chemoattractant protein-1 (MCP-1, also called CCL2) is related to RA disease activity, and epigenetic modifications are hypothesized to regulate gene expression in RA pathogenesis. We studied the effects of two TNF-α inhibitors, etanercept and adalimumab, on CCL2 expression and the potentially associated intracellular mechanisms, including epigenetic regulation. Etanercept and adalimumab decreased CCL2 production in THP-1 cells and human primary monocytes, as detected using enzyme-linked immunosorbent assays, and these changes in the CCL2 levels were independent of the TNF-α levels. Etanercept and adalimumab suppressed mitogen-activated protein kinase (MAPK) phospho-p38, phospho-JNK, phospho-ERK and nuclear factor-κB (NF-κB) phospho-p65, as demonstrated using western blot analyses. The investigation of epigenetic modifications using chromatin immunoprecipitation revealed that etanercept and adalimumab down-regulated acetylation of histone (H)3 and H4 in the CCL2 promoter region by decreasing the recruitment of the NF-κB associated acetyltransferases p300, CBP and PCAF. Etanercept and adalimumab also down-regulated trimethylation of H3K4, H3K27, H3K36 and H3K79 in the CCL2 promoter region by decreasing the expression of the related methyltransferases WDR5 and Smyd2. We demonstrated that TNF-α inhibitors exert immunomodulatory effects on CCL2 expression in human monocytes via MAPKs, NF-κB and epigenetic modifications. These findings broaden the mechanistic knowledge related to TNF-α inhibitors and provide novel therapeutic targets for RA.

Cysteinyl leukotriene receptor antagonist epigenetically modulates cytokine expression and maturation of human myeloid dendritic cells.

BACKGROUND: Cysteinyl leukotriene receptor antagonists are important controllers in treating asthma. Human myeloid DCs (mDCs) play critical roles in the pathogenesis of asthma. However, the effects of cysteinyl leukotriene receptor antagonist on human mDCs are unknown. METHODS: To investigate the effects of cysteinyl leukotriene receptor antagonist on the function of human mDCs, circulating mDCs were isolated from six health subjects. Human mDCs were pretreated with montelukast and were stimulated with toll-like receptor (TLR) ligands lipopolysaccharide (LPS) or polyinosinic-polycytidylic acid (poly I:C). Tumor necrosis factor (TNF)-α and interleukin (IL)-10 were measured by ELISA. Intracellular signaling was investigated by pathway inhibitors, western blot and chromatin immunoprecipitation. Costimulatory molecules expression was investigated by flow cytometry. T cell polarization function of mDCs was investigated by measuring interferon (IFN)-γ, IL-13, IL-10 and IL-17A production by T cells using mDC/T cell coculture assay. RESULTS: Montelukast suppressed TLR-mediated TNF-α expression via the NFκB-p65 and mitogen-activated protein kinase (MAPK)-JNK pathway, and enhanced TLR-mediated IL-10 expression via the MAPK-p38 pathway and epigenetic regulation by histone H3 acetylation. Montelukast suppressed LPS-induced CD80, CD86, CD40 and HLA-DR expression. Montelukast-treated mDCs suppressed IFN-γ and IL-13 production by T cells. CONCLUSION: Cysteinyl leukotriene receptor antagonist alters the function of human mDCs by epigenetically modulating cytokine expression, suppressing costimulatory molecules expression and inhibiting the ability to initiate Th1/Th2 responses. The effects of cysteinyl leukotriene receptor antagonist on human mDCs can be an important mechanism in treating asthma.

Tacrolimus suppresses atopic dermatitis-associated cytokines and chemokines in monocytes.

BACKGROUND: Calcineurin inhibitors (CNIs) exhibit remarkable efficacy in atopic dermatitis (AD). Tacrolimus, one type of CNI, is prevalently used to treat AD. AD is a chronic inflammatory disease that exhibits predominant infiltration of T-helper type 2 (Th2) cell in the acute phase and a mixed Th1 and Th0 cell pattern in chronic lesions. Cytokines such as tumor necrosis factor-α (TNF-α), Th2-related chemokines [e.g., macrophage-derived chemokine (MDC)/CCL22 and I-309/CCL1], Th1-related chemokines [e.g., interferon γ-induced protein 10 (IP-10)/CXCL10], and neutrophil chemoattractant growth-related oncogene-α (GRO-α)/CXCL1 are involved in the pathogenesis of AD. However, whether tacrolimus modulates the expression of AD-associated cytokines and chemokines remains unknown. The intracellular mechanisms of tacrolimus are also unclear. METHODS: Human monocytic cell line THP-1 cells were pretreated with tacrolimus and stimulated with lipopolysaccharide (LPS). The MDC, I-309, IP-10, GRO-α, and TNF-α concentrations of the cell supernatants were measured using enzyme-linked immunosorbent assay. Intracellular signaling was investigated using the Western blot analysis. RESULTS: Tacrolimus suppressed the expression of MDC, IP-10, I-309, GRO-α, and TNF-α in LPS-stimulated THP-1 cells in a dose- and time-dependent manner. All three mitogen-activated protein kinase (MAPK) inhibitors and the nuclear factor-κB inhibitor suppressed LPS-induced MDC, I-309, and TNF-α expressions in THP-1 cells. Only MAPK inhibitors suppressed LPS-induced expression of IP-10 and GRO-α. Tacrolimus suppressed the LPS-induced phosphorylation of MAPK-extracellular signal-related kinase (ERK). CONCLUSION: Tacrolimus suppressed LPS-induced MDC, I-309, IP-10, GRO-α, and TNF-α expressions in monocytes through the MAPK-ERK pathway; thus, tacrolimus may yield therapeutic efficacy by modulating AD-associated cytokines and chemokines.

Use of Fomepizole in Pediatric Methanol Exposure: The First Case Report in Taiwan and a Literature Review.

Methanol poisoning is rare in the pediatric population, but a delay in diagnosis and intervention may cause severe morbidity and mortality. The current therapy for methanol poisoning is ethanol or fomepizole, which acts as a competitive inhibitor of hepatic alcohol dehydrogenase to inhibit the production of toxic metabolites derived from the oxidation of methanol. However, clinical experience in pediatric methanol poisoning is limited, and the safety profiles of the antidotes have not been established in children, especially in Asian populations. This is the first case to describe the use of fomepizole in a child with methanol exposure in Taiwan.

Effect of prostaglandin I2 analogs on monocyte chemoattractant protein-1 in human monocyte and macrophage.

Chemokines play essential roles during inflammatory responses and in pathogenesis of inflammatory diseases. Monocyte chemotactic protein-1 (MCP-1) is a critical chemokine in the development of atherosclerosis and acute cardiovascular syndromes. MCP-1, by its chemotactic activity, causes diapedesis of monocytes from the lumen to the subendothelial space that leads to atherosclerotic plaque formation. Prostaglandin I2 (PGI2) analogs are used clinically for patients with pulmonary hypertension and have anti-inflammatory effects. However, little is known about the effect of PGI2 analogs on the MCP-1 production in human monocytes and macrophages. We investigated the effects of three conventional (iloprost, beraprost and treprostinil) and one new (ONO-1301) PGI2 analogs, on the expression of MCP-1 expression in human monocytes and macrophages. Human monocyte cell line, THP-1 cell, was treated with PGI2 analogs after LPS stimulation. Supernatants were harvested to measure MCP-1 levels and measured by ELISA. To explore which receptors involved the effects of PGI2 analogs on the expression of MCP-1 expression, IP and EP, PPAR-α and PPAR-γ receptor antagonists were used. Forskolin, a cAMP activator, was used to further confirm the involvement of cAMP on MCP-1 production in human monocytes. Three PGI2 analogs suppressed LPS-induced MCP-1 production in THP-1 cells and THP-1-induced macrophages. Higher concentrations of ONO-1301 also had the suppressive effect. CAY 10449, an IP receptor antagonist, could reverse the effects on MCP-1 production of iloprost on THP-1 cells. Other reported PGI2 receptor antagonists including EP1, EP2, EP4, PPAR-α and PPAR-γ antagonists could not reverse the effect. Forskolin, a cAMP activator, also suppressed MCP-1 production in THP-1 cells. PGI2 analogs suppressed LPS-induced MCP-1 production in human monocytes and macrophages via the IP receptor and cAMP pathway. The new PGI2 analog (ONO-1301) was not better than conventional PGI2 analog in the suppression of MCP-1 production in human monocytes.

The effects of environmental toxins on allergic inflammation.

The prevalence of asthma and allergic disease has increased worldwide over the last few decades. Many common environmental factors are associated with this increase. Several theories have been proposed to account for this trend, especially those concerning the impact of environmental toxicants. The development of the immune system, particularly in the prenatal period, has far-reaching consequences for health during early childhood, and throughout adult life. One underlying mechanism for the increased levels of allergic responses, secondary to exposure, appears to be an imbalance in the T-helper function caused by exposure to the toxicants. Exposure to environmental endocrine-disrupting chemicals can result in dramatic changes in cytokine production, the activity of the immune system, the overall Th1 and Th2 balance, and in mediators of type 1 hypersensitivity mediators, such as IgE. Passive exposure to tobacco smoke is a common risk factor for wheezing and asthma in children. People living in urban areas and close to roads with a high volume of traffic, and high levels of diesel exhaust fumes, have the highest exposure to environmental compounds, and these people are strongly linked with type 1 hypersensitivity disorders and enhanced Th2 responses. These data are consistent with epidemiological research that has consistently detected increased incidences of allergies and asthma in people living in these locations. During recent decades more than 100,000 new chemicals have been used in common consumer products and are released into the everyday environment. Therefore, in this review, we discuss the environmental effects on allergies of indoor and outside exposure.

Effects of the mTOR inhibitor rapamycin on monocyte-secreted chemokines.

BACKGROUND: Mammalian target of rapamycin (mTOR) inhibitors, such as sirolimus and its derivative, everolimus, are potent immunosuppressive and antiproliferative drugs. Inflammatory diseases are characterized by immunological dysfunction, and monocyte recruitment underlies the mechanism of cell damage. Chemokines attract inflammatory cells to sites of inflammation. Interleukin-8 (IL-8/CXCL8); the monocyte chemoattractant protein-1 (MCP-1/CCL2); the regulated on activation, normal T cell expressed, presumably secreted protein (RANTES/CCL5); the macrophage inflammatory protein (MIP)-1α (CCL3); and MIP-1ß (CCL4) are involved in the pathogenesis of inflammation. However, whether mTOR inhibitors moderate the production of chemokines in monocytes remains unclear. METHODS: A human monocyte cell line, THP-1, and primary monocytes obtained from human volunteers, were stimulated using lipopolysaccharide (LPS), and then treated with sirolimus. The expression of the MCP-1, RANTES, IL-8, MIP-1α, MIP-1ß, and TNF-α proteins was measured using enzyme-linked immunosorbent assays, and intracellular signalling was examined using western blotting. RESULTS: Sirolimus significantly suppressed the LPS-induced expression of MCP-1, IL-8, RANTES, MIP-1α, and MIP-1ß in the THP-1 cells and human primary monocytes. The mitogen-activated protein kinase (MAPK) inhibitors that were examined suppressed the LPS-induced expression of MCP-1, IL-8, RANTES, MIP-1α, and MIP-1ß. In addition, sirolimus suppressed the LPS-induced phosphorylation of p38 and p65 in the THP-1 and human primary monocytes. CONCLUSION: Sirolimus downregulates the expression of chemokines in monocytes, including MCP-1, RANTES, IL-8, MIP-1α, and MIP-1ß, by inhibiting the NF-κB-p65 and MAPK-p38 signalling pathways.