TNF-α-induced protein 3 is a key player in childhood asthma development and environment-mediated protection.

BACKGROUND: Childhood asthma prevalence is significantly greater in urban areas compared with rural/farm environments. Murine studies have shown that TNF-α-induced protein 3 (TNFAIP3; A20), an anti-inflammatory regulator of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, mediates environmentally induced asthma protection. OBJECTIVE: We aimed to determine the role of TNFAIP3 for asthma development in childhood and the immunomodulatory effects of environmental factors. METHODS: In a representative selection of 250 of 2168 children from 2 prospective birth cohorts and 2 cross-sectional studies, we analyzed blood cells of healthy and asthmatic children from urban and rural/farm environments from Europe and China. PBMCs were stimulated ex vivo with dust from "asthma-protective" farms or LPS. NF-κB signaling-related gene and protein expression was assessed in PBMCs and multiplex gene expression assays (NanoString Technologies) in isolated dendritic cells of schoolchildren and in cord blood mononuclear cells from newborns. RESULTS: Anti-inflammatory TNFAIP3 gene and protein expression was consistently decreased, whereas proinflammatory Toll-like receptor 4 expression was increased in urban asthmatic patients (P < .05), reflecting their increased inflammatory status. Ex vivo farm dust or LPS stimulation restored TNFAIP3 expression to healthy levels in asthmatic patients and shifted NF-κB signaling-associated gene expression toward an anti-inflammatory state (P < .001). Farm/rural children had lower expression, indicating tolerance induction by continuous environmental exposure. Newborns with asthma at school age had reduced TNFAIP3 expression at birth, suggesting TNFAIP3 as a possible biomarker predicting subsequent asthma. CONCLUSION: Our data indicate TNFAIP3 as a key regulator during childhood asthma development and its environmentally mediated protection. Because environmental dust exposure conferred the anti-inflammatory effects, it might represent a promising future agent for asthma prevention and treatment.

Aberrant Expression of Novel Cytokine IL-38 and Regulatory T Lymphocytes in Childhood Asthma.

We investigated the expression of novel anti-inflammatory interleukin (IL)-38 and regulatory T (Treg) lymphocytes in childhood asthma patients. The protein and mRNA expression level of IL-38, periostin, peripheral CD4⁺CD25⁺CD134⁺ T lymphocytes as well as CD4⁺CD25(high)FoxP3⁺ and CD4⁺CD25(high)CD127(-) Treg lymphocytes from 40 asthmatic patients and 20 normal control (NC) subjects were studied using ELISA, qPCR and flow cytometry. Serum and supernatant cytokines/chemokines were determined by multiplex assay. Serum IL-38, IL-5, IL-17, IL-6, interferon-γ, periostin, IL-1ß and IL-13 concentrations were significantly higher in asthmatic patients with or without steroid treatment than those in controls (all p < 0.05). The percentages of both CD4⁺CD25(high)FoxP3⁺ and CD4⁺CD25(high)CD127(-) Treg lymphocytes were markedly decreased in asthmatic patients with and without steroid treatment than those in controls (all p < 0.05). The elevated IL-38 concentration negatively correlated with the percentage of Treg lymphocytes in asthmatic patients with high level (>40 ng/mL) of periostin (p < 0.05). Although the comparable mRNA levels of IL-38 and its receptor IL-36R were found between patients and controls, the mRNA level of IL-38 positively correlated with IL-36R and negatively correlated with IL-10 in all asthmatic patients (both p < 0.05). The percentage of CD4⁺CD25⁺CD134⁺ activated T lymphocytes was also significantly higher in asthmatic patients with steroid treatment than those in controls (p < 0.05). This cross-sectional study demonstrated that the overexpression of circulating IL-38 may play a role in the immunopathogenesis in asthma.

Anti-Inflammatory Activities of Pentaherbs Formula, Berberine, Gallic Acid and Chlorogenic Acid in Atopic Dermatitis-Like Skin Inflammation.

Atopic dermatitis (AD) is a common allergic skin disease, characterized by dryness, itchiness, thickening and inflammation of the skin. Infiltration of eosinophils into the dermal layer and presence of edema are typical characteristics in the skin biopsy of AD patients. Previous in vitro and clinical studies showed that the Pentaherbs formula (PHF) consisting of five traditional Chinese herbal medicines, Flos Lonicerae, Herba Menthae, Cortex Phellodendri, Cortex Moutan and Rhizoma Atractylodis at w/w ratio of 2:1:2:2:2 exhibited therapeutic potential in treating AD. In this study, an in vivo murine model with oxazolone (OXA)-mediated dermatitis was used to elucidate the efficacy of PHF. Active ingredients of PHF water extract were also identified and quantified, and their in vitro anti-inflammatory activities on pruritogenic cytokine IL-31- and alarmin IL-33-activated human eosinophils and dermal fibroblasts were evaluated. Ear swelling, epidermis thickening and eosinophils infiltration in epidermal and dermal layers, and the release of serum IL-12 of the murine OXA-mediated dermatitis were significantly reduced upon oral or topical treatment with PHF (all p < 0.05). Gallic acid, chlorogenic acid and berberine contents (w/w) in PHF were found to be 0.479%, 1.201% and 0.022%, respectively. Gallic acid and chlorogenic acid could suppress the release of pro-inflammatory cytokine IL-6 and chemokine CCL7 and CXCL8, respectively, in IL-31- and IL-33-treated eosinophils-dermal fibroblasts co-culture; while berberine could suppress the release of IL-6, CXCL8, CCL2 and CCL7 in the eosinophil culture and eosinophils-dermal fibroblasts co-culture (all p < 0.05). These findings suggest that PHF can ameliorate allergic inflammation and attenuate the activation of eosinophils.

Childhood asthma is associated with polymorphic markers of PROC on 2q14 in addition to 17q21 locus.

BACKGROUND: Childhood asthma is caused by both genetic and environmental factors. The first genomewide association study (GWAS) for asthma revealed putative candidates on nine chromosomal regions in Caucasians, with 17q21 locus being the most widely replicated one. However, there was no replication study for the other loci. This study investigated genetic associations between childhood asthma and autosomal single nucleotide polymorphisms (SNPs) on eight loci reported in the first GWAS among Hong Kong Chinese. METHODS: 510 asthmatic children and 510 non-allergic controls were recruited. 110 tagging SNPs selected based on r(2 ) ≥ 0.80 and minor allele frequency ≥0.05 for Han Chinese among all SNPs located 50-kb upstream and downstream of significant autosomal SNPs were genotyped by TaqMan allelic discrimination assays. Transcription factor binding of SNPs was determined by electrophoretic mobility shift assay (EMSA). RESULTS: Asthma was significantly associated with SNPs on 17q21 and 2q14 loci. Twelve SNPs on 17q21 were associated with asthma, with rs6503527 being the most significant SNP. Five SNPs of protein C gene (PROC) on 2q14 were associated with asthma, with rs6755028 being the most significant SNP. Plasma protein C concentrations were higher in asthmatic patients than controls, and five PROC SNPs were associated with plasma protein C concentrations. EMSA showed specific differential binding of rs878461 to nuclear extracts from bronchial epithelial and hepatocarcinoma cell lines. CONCLUSIONS: Our findings identify PROC on 2q14 as a novel candidate for childhood asthma and replicate the genetic association for 17q21 locus. Rs878461 of PROC may increase asthma susceptibility by altering transcription factor binding.

Anti-inflammatory and anti-allergic activities of Pentaherb formula, Moutan Cortex (Danpi) and gallic acid.

Pentaherb formula (PHF) has been proven to improve the quality of life of children with atopic dermatitis without side effects. The aim of this study was to elucidate the potential anti-inflammatory and anti-allergic activities of PHF, Moutan Cortex (Danpi/DP) and gallic acid (GA) using human basophils (KU812 cells), which are crucial effector cells in allergic inflammation. PHF, DP and GA could significantly suppress the expression of allergic inflammatory cytokine IL-33-upregulated intercellular adhesion molecule (ICAM)-1, and the release of chemokines CCL2, CCL5, CXCL8 and inflammatory cytokine IL-6 from KU812 cells (all p < 0.05). With the combined use of dexamethasone (0.01 µg/mL) and GA (10 µg/mL), the suppression of ICAM-1 expression and CCL5 and IL-6 release of IL-33-activated KU812 cells were significantly greater than the use of GA alone (all p < 0.05). The suppression of the IL-33-induced activation of intracellular signalling molecules p38 mitogen activated protein kinase, nuclear factor-kB and c-Jun amino-terminal kinase in GA-treated KU812 cells could be the underlying mechanism for the suppression on ICAM-1, chemokines and cytokines. The combined use of dexamethasone with the natural products PHF or DP or GA might therefore enhance the development of a novel therapeutic modality for allergic inflammatory diseases with high potency and fewer side effects.

Genomic and proteomic analysis of invertebrate iridovirus type 9.

Iridoviruses (IV) are nuclear cytoplasmic large DNA viruses that are receiving increasing attention as sublethal pathogens of a range of insects. Invertebrate iridovirus type 9 (IIV-9; Wiseana iridovirus) is a member of the major phylogenetic group of iridoviruses for which there is very limited genomic and proteomic information. The genome is 205,791 bp, has a G+C content of 31%, and contains 191 predicted genes, with approximately 20% of its repeat sequences being located predominantly within coding regions. The repeated sequences include 11 proteins with helix-turn-helix motifs and genes encoding related tandem repeat amino acid sequences. Of the 191 proteins encoded by IIV-9, 108 are most closely related to orthologs in IIV-3 (Chloriridovirus genus), and 114 of the 126 IIV-3 genes have orthologs in IIV-9. In contrast, only 97 of 211 IIV-6 genes have orthologs in IIV-9. There is almost no conservation of gene order between IIV-3, IIV-6, and IIV-9. Phylogenetic analysis using a concatenated sequence of 26 core IV genes confirms that IIV-3 is more closely related to IIV-9 than to IIV-6, despite being from a different genus of the Iridoviridae. An interaction between IIV and small RNA regulatory systems is supported by the prediction of seven putative microRNA (miRNA) sequences combined with XRN exonuclease, RNase III, and double-stranded RNA binding activities encoded on the genome. Proteomic analysis of IIV-9 identified 64 proteins in the virus particle and, when combined with infected cell analysis, confirmed the expression of 94 viral proteins. This study provides the first full-genome and consequent proteomic analysis of group II IIV.

Thymic stromal lymphopoietin induces chemotactic and prosurvival effects in eosinophils: implications in allergic inflammation.

Thymic stromal lymphopoietin (TSLP) is highly expressed by bronchial epithelial cells and skin keratinocytes in allergic diseases. TSLP acts as a master switch for allergic inflammation through the activation of dendritic cells and mast cells for initiating inflammatory type 2 T-helper lymphocyte responses. To elucidate the immunological cascades of epithelium/keratinocyte-eosinophil-mediated allergic inflammation, we examined the modulating effects of TSLP on human eosinophils. Expression of TSLP receptor complex was detected by RT-PCR, flow cytometry, and Western blot. Adhesion molecules, cytokine, and chemokines were quantitated by flow cytometry or ELISA. Intracellular signal transduction molecules were measured by Western blot and flow cytometry. We observed that human eosinophils constitutively expressed functional heterodimeric TSLP receptor complex comprising TSLP-binding chain TSLPR and IL-7Ralpha chain. TSLP could significantly delay eosinophil apoptosis, up-regulate cell surface expression of adhesion molecule CD18 and intercellular adhesion molecule-1, but down-regulate L-selectin, enhance eosinophil adhesion onto fibronectin, and induce the release of inflammatory cytokine IL-6 and chemokines CXCL8, CXCL1, and CCL2 (all P < 0.05). All these effects were concentration dependent and TSLP specific. TSLP regulated the above effects through the activation of extracellular signal-regulated protein kinase, p38 mitogen-activated protein kinase, and NF-kappaB signaling pathway, but not signal transducer and activator of transcription 5 and 3, which were usually activated in other effector cells upon TSLP stimulation. Collectively, the above findings elucidate the proallergic mechanisms of TSLP via the activation of distinct intracellular signaling pathways in eosinophils.

Activation of human bronchial epithelial cells by inflammatory cytokines IL-27 and TNF-alpha: implications for immunopathophysiology of airway inflammation.

Interleukin (IL)-27 is a member of IL-6/IL-12 family cytokines produced by antigen-presenting cells in immune responses. IL-27 can drive the commitment of naive T cells to a T helper type 1 (Th1) phenotype and inhibit inflammation in later phases of infection. Human bronchial epithelial cells have been shown to express IL-27 receptor complex. In this study, we investigated the in vitro effects of IL-27, alone or in combination with inflammatory cytokine tumor necrosis factor (TNF)-alpha on the pro-inflammatory activation of human primary bronchial epithelial cells and the underlying intracellular signaling mechanisms. IL-27 was found to enhance intercellular adhesion molecule 1 (ICAM-1) expression on the surface of human bronchial epithelial cells, and a synergistic effect was observed in the combined treatment of IL-27 and TNF-alpha on the expression of ICAM-1. Although IL-27 did not alter the basal IL-6 secretion from bronchial epithelial cells, it could significantly augment TNF-alpha-induced IL-6 release. These synergistic effects on the up-regulation of ICAM-1 and IL-6 were partially due to the elevated expression of TNF-alpha receptor (p55TNFR) induced by IL-27. Further investigations showed that the elevation of ICAM-1 and IL-6 in human bronchial epithelial cells stimulated by IL-27 and TNF-alpha was differentially regulated by phosphatidylinositol 3-OH kinase (PI3K)-Akt, p38 mitogen-activated protein kinase, and nuclear factor-kappaB pathways. Our results therefore provide a new insight into the molecular mechanisms involved in airway inflammation.

Association of plasma soluble CTLA-4 with lung function and gene polymorphism in Chinese asthmatic children.

BACKGROUND: Cytotoxic T lymphocyte antigen 4 (CTLA-4) is known to downregulate the T(H)2 immune response. Recent studies have suggested an association of CTLA-4 polymorphisms with allergic diseases. We investigated the effects of single nucleotide polymorphisms (SNPs) of CTLA-4 on asthma traits and plasma sCTLA-4 in 298 Chinese asthmatic children and 175 controls. METHODS: Plasma sCTLA-4, total and allergen-specific IgE concentrations were measured by enzyme immunoassay. Six SNPs, namely -1147CT, +49AG, CT60, JO31, JO30 and JO27_1, in CTLA-4 were genotyped by restriction fragment length polymorphism. RESULTS: Plasma sCTLA-4 was negatively associated with FEV(1)/FVC (r = -0.146, p = 0.036) among our asthmatic patients. Analysis of locus-locus interaction by generalized multifactor dimensionality reduction showed that -1147CT was the best model for plasma sCTLA-4 with a cross-validation consistency of 10 out of 10 and a prediction error of 40.9% (p < 0.001). Multivariate regression analysis confirmed the association between plasma sCTLA-4 concentration with -1147CT among the 6 SNPs tested (p = 0.002) after adjustment for gender and age. The plasma sCTLA-4 concentration was significantly lower in patients homozygous for the C allele than in T allele carriers (p = 0.001). There was also a significant association between the most common haplotypes with low sCTLA-4 in asthmatics. We could not find any significant association between plasma total IgE, atopy and lung function with the 6 SNPs after Bonferroni correction. CONCLUSIONS: Plasma sCTLA-4 is associated with lung function and -1147CT polymorphism in Chinese asthmatic children. This may help to identify CTLA-4 signaling as a potential therapeutic target in asthma.

Signalling mechanisms regulating the activation of human eosinophils by mast-cell-derived chymase: implications for mast cell-eosinophil interaction in allergic inflammation.

Allergic diseases such as asthma and allergic dermatitis are associated with the degranulation of mast cells. Chymase, a mast-cell-specific protease, is the major component in mast cell granules that can induce eosinophil infiltration into inflammatory sites. We examined the immunopathological mechanisms for the activation of eosinophils by chymase in allergic inflammation. Cytokines were measured by cytometric bead array Flex Sets multiplex assay using flow cytometry and enzyme-linked immunosorbent assay. Adhesion molecules, migration and intracellular signalling pathways were assessed by flow cytometry, Boyden chamber assay and Western blot, respectively. Chymase suppressed the apoptosis of eosinophils and induce the release of the cytokine interleukin-6 (IL-6) and chemokines CXCL8, CCL2 and CXCL1 by eosinophils dose-dependently. It also up-regulated the surface expression of adhesion molecule CD18 and stimulated the chemokinetic migration of eosinophils. The expressions of adhesion molecules, cytokines and chemokines, and chemokinetic migration were differentially regulated by the activation of extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, Akt, Janus-activated kinase and nuclear factor-kappaB pathways. Chymase therefore plays a pivotal immunological role in the interaction between mast cells and eosinophils in allergic diseases such as allergic dermatitis by inducing adhesion molecule-mediated chemokinetic migration and inflammatory cytokines and chemokines of eosinophils, through multiple intracellular signalling molecules and transcription factor. Our results therefore provide a further biochemical basis for the pathogenesis of allergic inflammation consequent on the interaction between mast cells and eosinophils, and give insight for the development of new therapies.

Activation profile of intracellular mitogen-activated protein kinases in peripheral lymphocytes of patients with systemic lupus erythematosus.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease associated with aberrant activation of T and B lymphocytes. Abnormal activation of intracellular signaling molecules in lymphocytes by inflammatory cytokines can instigate the inflammation in SLE. MATERIALS AND METHODS: The activation of extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) in inflammatory cytokine IL-18-activated monocytes, CD4+ T helper (Th) lymphocytes, CD8+ T lymphocytes, and CD19+ B lymphocytes in 22 SLE patients and 20 sex- and age-matched control subjects were measured by flow cytometry. RESULTS AND DISCUSSION: The basal expressions of phospho-p38 MAPK in CD4+ T lymphocytes, CD8+ T lymphocytes, and B lymphocytes were significantly higher in SLE patients than controls (all p<0.05). The expression of phospho-p38 MAPK in CD4+ T lymphocytes, CD8+ T lymphocytes and B lymphocytes, and phospho-JNK in CD8+ T lymphocytes and B lymphocytes was also significantly elevated in SLE patients upon the activation by IL-18, exhibiting significant correlation with the plasma concentrations of Th1 chemokine CXCL10 (all p<0.05). The expression of phospho-JNK in IL-18 activated CD8+ T lymphocytes and the relative % fold increase of the expression of phospho-JNK upon IL-18 activation in B lymphocytes were significantly correlated with SLE disease activity index (both p<0.05). CONCLUSION: The inflammation-mediated activation of JNK and p38 MAPK signaling pathways in T and B lymphocytes can be the underlying intracellular mechanisms causing lymphocyte hyperactivity in SLE.

Cytokine responses in a severe case of glandular fever treated successfully with foscarnet combined with prednisolone and intravenous immunoglobulin.

Viral loads and cytokine responses Epstein-Barr virus (EBV) were measured in an 18-year-old boy with severe glandular fever complicated by a mild anaemia, severe thrombocytopaenia and neutropaenia. Hepatosplenomegaly was detected by abdominal ultrasound in the presence of significant hepatitis. Cytokine testing demonstrated elevated cell-mediated Th1 (IFN-gamma, IL-12, sTNFR1, CXCL10, CXCL9 and CCL3) and humoral Th2 (IL-4) immune responses. Serum antibodies to EBV virus capsid antigen (VCA) IgM and IgG antibodies were detected, together with a raised EBV DNA level (up to about 70,000 DNA copies/mL) in the acute phase of the illness. This EBV DNA load decreased rapidly in response to treatment with a combination of foscarnet, intravenous immunoglobulin and prednisolone, and the boy's symptoms settled eventually after approximately 50 days of illness, following this combined antiviral and immune-modulating therapy. Detailed immunological, virological, haematological and biochemical laboratory parameters are presented to document this patient's severe EBV disease and eventual recovery.

Association of early growth response-1 gene polymorphisms with total IgE and atopy in asthmatic children.

Early growth response-1 (Egr-1) is expressed in human airways and found to modulate tumor necrosis factor, immunoglobulin E (IgE), airway responsiveness, and interleukin-13-induced inflammation in mice. We investigated the effects of Chinese-tagging single nucleotide polymorphisms (SNPs) of Egr-1 on asthma traits in 298 Chinese asthmatic children and 175 controls, and a replication community cohort of 191 controls. Tag SNP (-4071 A-->G) and three additional SNPs (-1427 C-->T, -151 C-->T and IVS1 -42 C-->T) were genotyped by restriction fragment length polymorphism (RFLP). Significant associations were found between plasma total IgE concentration and -4071 A-->G (p = 0.008) and IVS1 -42 C-->T (p = 0.027) in asthmatic patients. After Bonferroni correction, only -4071 A-->G showed significant association. Multivariate regression analysis confirmed this significant association with a standardized coefficient beta of 0.156 (95% CI: 0.046-0.317; p = 0.009) in asthmatics among the three SNPs with age and gender-adjusted. In -4071 A-->G, IgE(log) was significantly higher in patients with the GG genotype than the AA genotype (p = 0.009). In addition, -4071 A-->G was significantly associated with atopy (p = 0.016) and high total IgE concentration (p = 0.030) among asthmatics. Patients with the G allele had a 3.5-fold risk of having atopy and a 2.0-fold risk of having high total IgE concentration than those homozygous for the A allele. This is the first report to show significant association of Egr-1 polymorphisms with plasma total IgE and atopy in asthmatics. It may help to explore the pharmacogenetics of Egr-1 inhibitors.

IL33: Roles in Allergic Inflammation and Therapeutic Perspectives.

Interleukin (IL)-33 belongs to IL-1 cytokine family which is constitutively produced from the structural and lining cells including fibroblasts, endothelial cells, and epithelial cells of skin, gastrointestinal tract, and lungs that are exposed to the environment. Different from most cytokines that are actively secreted from cells, nuclear cytokine IL-33 is passively released during cell necrosis or when tissues are damaged, suggesting that it may function as an alarmin that alerts the immune system after endothelial or epithelial cell damage during infection, physical stress, or trauma. IL-33 plays important roles in type-2 innate immunity via activation of allergic inflammation-related eosinophils, basophils, mast cells, macrophages, and group 2 innate lymphoid cells (ILC2s) through its receptor ST2. In this review, we focus on the recent advances of the underlying intercellular and intracellular mechanisms by which IL-33 can regulate the allergic inflammation in various allergic diseases including allergic asthma and atopic dermatitis. The future pharmacological strategy and application of traditional Chinese medicines targeting the IL-33/ST2 axis for anti-inflammatory therapy of allergic diseases were also discussed.

Mucosal immunization with purified ClpP could elicit protective efficacy against pneumococcal pneumonia and sepsis in mice.

Caseinolytic protease (ClpP) has been found to be highly conserved among different strains of Streptococcus pneumoniae and intraperitoneal immunization with ClpP could elicit protection against invasive pneumococcal infections. In this study, mucosal immunization with ClpP antigen induced both systemic and mucosal antibodies, and in this way reduced lung colonization in an invasive pneumococcal pneumonia model and also protected mice against death in an intraperitoneal-sepsis model. Surface localization of ClpP was confirmed using flow cytometry analysis. Furthermore, characterization of human sera for anti-ClpP IgG antibody levels demonstrated that ClpP protein was immunogenic in healthy children and was expressed during disease based on the elevated antibody levels in infected individuals. Finally, we describe that in vitro functional anti-ClpP antibody could kill streptococcus pneumoniae by polymorphonuclear leukocytes in a complement-dependent assay. To our knowledge, this is the first study about the protective efficacy of mucosal immunization with ClpP as a promising pneumococcal protein antigen.

Interleukin-31 induces cytokine and chemokine production from human bronchial epithelial cells through activation of mitogen-activated protein kinase signalling pathways: implications for the allergic response.

Interleukin-31 (IL-31) is a novel T-helper-lymphocyte-derived cytokine that plays an important role in allergic skin inflammation and atopic dermatitis. It has recently been implicated in bronchial inflammation. We investigated the functions and mechanisms of IL-31-induced activation of human bronchial epithelial cells. The gene and protein expressions of candidate cytokines/chemokines from IL-31-stimulated human bronchial epithelial BEAS-2B cells were first quantified by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The activity of different mitogen-activated protein kinases (MAPKs) in IL-31-stimulated BEAS-2B cells was assessed by Western blot. The IL-31 could significantly elevate the gene and protein expressions of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1/CCL2) of BEAS-2B cells in both time-dependently and dose-dependently. Combination of IL-31 with either IL-4 or IL-13 further enhanced VEGF and CCL2 production while IL-31 could synergistically augment the release of EGF, VEGF, CCL2, IL-6 and IL-8 in cocultures of BEAS-2B cells and eosinophils. In addition, IL-31 could activate p38 MAPK, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) of BEAS-2B cells. Selective inhibitors of p38 MAPK (SB203580), ERK (PD98059), and JNK (SP600125) could differentially inhibit the production of EGF, VEGF and CCL2, thereby suggesting a role for MAPKs in IL-31 functions. In conclusion, the activation of MAPKs can be crucial for IL-31-mediated activation of bronchial epithelial cells, thereby providing an immunological role for IL-31 in bronchial inflammation, at least partly, via epithelial EGF, VEGF and CCL2 production.

Cadmium and lead in Hong Kong school children.

AIM: Cadmium (Cd) and lead (Pb) are toxic elements in our environment. This study is to determine the reference intervals of Cd and Pb in blood and urine from Hong Kong school children and to identify their determinants. METHODS: A total of 2209 secondary school children and 893 preschool children were recruited. Cd and Pb in blood and urine were measured by inductively-coupled plasma mass spectrometry. RESULTS: Blood Cd was affected by age, smoking and residential district, while urine Cd was influenced by age and blood Cd. Blood Cd was positively correlated with smoking as confirmed by urinary cotinine (rho  = 0.183, p  <  0.001, n = 2074). Blood Pb was dependent on gender and residential district, while urinary Pb was dependent on gender and blood Pb. Students from schools of lower academic grading had higher blood Cd and Pb than those from higher academic grading schools (p < 0.001, respectively). Urinary albumin was positively associated with urinary Cd and Pb. CONCLUSIONS: Using a non-occupationally exposed population, the reference ranges are: blood Cd < 21.9  nmol/L for smokers and < 8.8  nmol/L for non-smokers, and blood Pb < 203.8  nmol/L. Reference intervals for urinary Cd and Pb are also reported.

Activation of human fibroblast-like synoviocytes by uric acid crystals in rheumatoid arthritis.

Hyperuricemia-mediated uric acid crystal formation may cause joint inflammation and provoke the destruction of joints through the activation of inflammasome-mediated innate immune responses. However, the immunopathological effects and underlying intracellular regulatory mechanisms of uric acid crystal-mediated activation of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) have not been elucidated. Therefore, we investigated the in vitro effects of monosodium urate crystals, alone or in combination with the inflammatory cytokines tumor-necrosis factor (TNF)-α or interleukin (IL)-1ß, on the activation of human FLS from RA patients and normal control subjects and the underlying intracellular signaling mechanisms of treatment with these crystals. Monosodium urate crystals were able to significantly increase the release of the inflammatory cytokine IL-6, the chemokine CXCL8 and the matrix metalloproteinase (MMP)-1 from both normal and RA-FLS (all P<0.05). Moreover, the additive or synergistic effect on the release of IL-6, CXCL8 and MMP-1 from both normal and RA-FLS was observed following the combined treatment with monosodium urate crystals and TNF-α or IL-1ß. Further experiments showed that the release of the measured inflammatory cytokine, chemokine and MMP-1 stimulated by monosodium urate crystals were differentially regulated by the intracellular activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase pathways but not the p38 mitogen-activated protein kinase pathway. Our results therefore provide a new insight into the uric acid crystal-activated immunopathological mechanisms mediated by distinct intracellular signal transduction pathways leading to joint inflammation in RA.

Effects of inflammatory cytokine IL-27 on the activation of fibroblast-like synoviocytes in rheumatoid arthritis.

INTRODUCTION: Interleukin (IL)-27 is a novel member of the IL-6/IL-12 family cytokines that are produced early by antigen-presenting cells in T helper (Th)1-mediated inflammation. Elevated expression of IL-27 has been detected in the synovial membranes and fluid of rheumatoid arthritis (RA). METHODS: We investigated the in vitro effects of IL-27, alone or in combination with inflammatory cytokine tumor necrosis factor (TNF)-α or IL-1 ß on the pro-inflammatory activation of human primary fibroblast-like synoviocytes (FLS) from RA patients and normal control subjects, and the underlying intracellular signaling molecules were determined by intracellular staining using flow cytometry. RESULTS: Significantly higher plasma concentration of IL-27 was found in RA patients (n = 112) than control subjects (n = 46). Both control and RA-FLS constitutively express functional IL-27 receptor heterodimer, gp130 and WSX-1, with more potent IL-27-mediated activation of signal transducers and activators of transcription (STAT)1 in RA-FLS. IL-27 was found to induce significantly higher cell surface expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 and release of inflammatory chemokine IL-6, CCL2, CXCL9, CXCL10 and matrix metalloproteinase-1 of RA-FLS than that of control FLS (all P < 0.05). Moreover, an additive or synergistic effect was observed in the combined treatment of IL-27 and TNF-α or IL-1 ß on the surface expression of ICAM-1 and VCAM-1 and the release of CXCL9 and CXCL10 of RA-FLS. Further investigations showed that the expression of ICAM-1, VCAM-1 and chemokines stimulated by IL-27 was differentially regulated by intracellular activation of phosphatidylinositol 3-OH kinase-AKT, c-Jun amino-terminal kinase and Janus kinase pathways. CONCLUSIONS: Our results therefore provide a new insight into the IL-27-activated immunopathological mechanisms mediated by distinct intracellular signal transductions in joint inflammation of RA.