Interleukin-17A and Toll-Like Receptor 3 Ligand Poly(I:C) Synergistically Induced Neutrophil Chemoattractant Production by Bronchial Epithelial Cells

Chronic inflammatory airway diseases, such as bronchial asthma and chronic obstructive pulmonary disease, are common respiratory disorders worldwide. Exacerbations of these diseases are frequent and worsen patients’ respiratory condition and overall health. However, the mechanisms of exacerbation have not been fully elucidated. Recently, it was reported that interleukin (IL)-17A might play an important role in neutrophilic inflammation, which is characteristic of such exacerbations, through increased production of neutrophil chemoattractants. Therefore, we hypothesized that IL-17A was involved in the pathogenesis of acute exacerbation, due to viral infection in chronic inflammatory airway diseases. In this study, we assessed chemokine production by bronchial epithelial cells and investigated the underlying mechanisms. Comprehensive chemokine analysis showed that, compared with poly(I:C) alone, co-stimulation of BEAS-2B cells with IL-17A and poly(I:C) strongly induced production of such neutrophil chemoattractants as CXC chemokine ligand (CXCL)8, growth-related oncogene (GRO), and CXCL1. Co-stimulation synergistically induced CXCL8 and CXCL1 mRNA and protein production by BEAS-2B cells and normal human bronchial epithelial cells. Poly(I:C) induced chemokine expression by BEAS-2B cells mainly via Toll-like receptor 3/TIR-domain-containing adapter-inducing interferon-β–mediated signals. The co-stimulation with IL-17A and poly(I:C) markedly activated the p38 and extracellular-signal-regulated kinase 1/2 pathway, compared with poly(I:C), although there was little change in nuclear factor-κB translocation into the nucleus or the transcriptional activities of nuclear factor-κB and activator protein 1. IL-17A promoted stabilization of CXCL8 mRNA in BEAS-2B cells treated with poly(I:C). In conclusion, IL-17A appears to be involved in the pathogenesis of chronic inflammatory airway disease exacerbation, due to viral infection by promoting release of neutrophil chemoattractants from bronchial epithelial cells.

The expression and regulation of chemerin in the epidermis

Chemerin is a protein ligand for the G protein-coupled receptor CMKLR1 and also binds to two atypical heptahelical receptors, CCRL2 and GPR1. Chemerin is a leukocyte attractant, adipokine, and antimicrobial protein. Although chemerin was initially identified as a highly expressed gene in healthy skin keratinocytes that was downregulated during psoriasis, the regulation of chemerin and its receptors in the skin by specific cytokines and microbial factors remains unexplored. Here we show that chemerin, CMKLR1, CCRL2 and GPR1 are expressed in human and mouse epidermis, suggesting that this tissue may be both a source and target for chemerin mediated effects. In human skin cultures, chemerin is significantly downregulated by IL-17 and IL-22, key cytokines implicated in psoriasis, whereas it is upregulated by acute phase cytokines oncostatin M and IL-1β. Moreover, we show that human keratinocytes in vitro and mouse skin in vivo respond to specific microbial signals to regulate expression levels of chemerin and its receptors. Furthermore, in a cutaneous infection model, chemerin is required for maximal bactericidal effects in vivo. Together, our findings reveal previously uncharacterized regulators of chemerin expression in skin and identify a physiologic role for chemerin in skin barrier defense against microbial pathogens.

Inhibitory action of levocetirizine on the production of eosinophil chemoattractants RANTES and eotaxin in vitro and in vivo

Eosinophils are well known to play essential roles in the development and maintenance of allergic diseases. However, the influence of histamine H1 receptor antagonists on eosinophil functions, especially chemokine production, are not well-defined. Therefore, in the present study, we examined the influence of histamine H1 receptor antagonist on chemokine production by eosinophils through the use of levocetirizine in vitro and in vivo. Eosinophils prepared from mice were stimulated with specific antigens in the presence of different concentrations of levocetirizine. After 24 h, regulated on activation normal T cell expressed and secreted (RANTES) and eotaxin levels in culture supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Patients with Japanese cedar pollinosis were treated with 5 mg levocetirizine once a day for four weeks during the pollen season (February 2012 to April 2012). RANTES and eotaxin levels in nasal secretions were also examined by ELISA. The addition of levocetirizine to eosinophil cultures caused a dose-dependent decrease in the ability of cells to produce RANTES and eotaxin in response to antigen stimulation, and the minimum concentration that caused a significant decrease was 0.05 μM. Although cetirizine also exerted suppressive effects on the production of RANTES and eotaxin by eosinophils, the minimum concentration that caused significant suppression was 0.15 μM, which was three-times higher than that of levocetirizine. Oral administration of levocetirizine for four weeks also reduced RANTES and eotaxin levels in nasal secretions from patients with pollinosis, along with attenuation of clinical symptoms. The ability of levocetirizine to reduce RANTES and eotaxin levels may account, at least in part, for the clinical efficacy of the agent for allergic disorders, including allergic rhinitis.

Suppressive activity of quercetin on the production of eosinophil chemoattractants from eosinophils in vitro

Quercetin, a flavonoid found in a wide variety of plants, has been studied for possible health benefits, and it has been found to have potent anti-oxidant, anti-viral and anticancer effects. Although quercetin is also reported to act as an antihistamine and an anti-inflammatory through the suppression of mast cell activation, the influence of quercetin on eosinophil activation is not fully understood. The present study, therefore, was undertaken to examine the influence of quercetin on eosinophil activation, especially chemokine production by using an in vitro cell culture technique. Eosinophils (5×10(5) cells/ml) obtained from Mesocestoides corti-infected mice were stimulated with 200 ng/ml stem cell factor in the presence of different concentrations of quercetin for 24 h. Chemokine, eotaxin, regulated on activation normal T cell expressed and secreted and macrophage inflammatory protein-1β, levels in culture supernatants were examined by enzyme-linked immunosorbent assay (ELISA). We also examined the influence of quercetin on chemokine mRNA expression and transcription factor, nuclear factor kappa B and activator protein 1, activation by real-time reverse transcription polymerase chain reaction and ELISA, respectively. Treatment of eosinophils with quercetin at more than 4.5 μM caused a significant decrease in chemokine levels in culture supernatants. Quercetin also suppressed transcription factor activation in 4 h-cultured cells and mRNA expression of chemokine in 12 h-cultured cells, which were increased by stem cell factor stimulation. These results may suggest that quercetin inhibits eosinophil activation, especially chemokine production, and results in inhibition of the development of eosinophilic inflammatory responses.

Elastase and tryptase govern TNFα-mediated production of active chemerin by adipocytes

Chemerin is a leukocyte chemoattractant and adipokine with important immune and metabolic roles. Chemerin, secreted in an inactive form prochemerin, undergoes C-terminal proteolytic cleavage to generate active chemerin, a ligand for the chemokine-like receptor-1 (CMKLR1). We previously identified that adipocytes secrete and activate chemerin. Following treatment with the obesity-associated inflammatory mediator TNFα, unknown adipocyte mechanisms are altered resulting in an increased ratio of active to total chemerin production. Based on these findings we hypothesized adipocytes produce proteases capable of modifying chemerin and its ability to activate CMKRL1. 3T3-L1 adipocytes expressed mRNA of immunocyte and fibrinolytic proteases known to activate chemerin in vitro. Following treatment with a general protease inhibitor cocktail (PIC), the TNFα-stimulated increase in apparent active chemerin concentration in adipocyte media was amplified 10-fold, as measured by CMKLR1 activation. When the components of the PIC were investigated individually, aprotinin, a serine protease inhibitor, blocked 90% of the TNFα-associated increase in active chemerin. The serine proteases, elastase and tryptase were elevated in adipocyte media following treatment with TNFα and their targeted neutralization recapitulated the aprotinin-mediated effects. In contrast, bestatin, an aminopeptidase inhibitor, further elevated the TNFα-associated increase in active chemerin. Our results support that adipocytes regulate chemerin by serine protease-mediated activation pathways and aminopeptidase deactivation pathways. Following TNFα treatment, increased elastase and tryptase modify the balance between activation and deactivation, elevating active chemerin concentration in adipocyte media and subsequent CMKLR1 activation.

ChemR23 dampens lung inflammation and enhances anti-viral immunity in a mouse model of acute viral pneumonia

Viral diseases of the respiratory tract, which include influenza pandemic, children acute bronchiolitis, and viral pneumonia of the elderly, represent major health problems. Plasmacytoid dendritic cells play an important role in anti-viral immunity, and these cells were recently shown to express ChemR23, the receptor for the chemoattractant protein chemerin, which is expressed by epithelial cells in the lung. Our aim was to determine the role played by the chemerin/ChemR23 system in the physiopathology of viral pneumonia, using the pneumonia virus of mice (PVM) as a model. Wild-type and ChemR23 knock-out mice were infected by PVM and followed for functional and inflammatory parameters. ChemR23^−/− mice displayed higher mortality/morbidity, alteration of lung function, delayed viral clearance and increased neutrophilic infiltration. We demonstrated in these mice a lower recruitment of plasmacytoid dendritic cells and a reduction in type I interferon production. The role of plasmacytoid dendritic cells was further addressed by performing depletion and adoptive transfer experiments as well as by the generation of chimeric mice, demonstrating two opposite effects of the chemerin/ChemR23 system. First, the ChemR23-dependent recruitment of plasmacytoid dendritic cells contributes to adaptive immune responses and viral clearance, but also enhances the inflammatory response. Second, increased morbidity/mortality in ChemR23^−/− mice is not due to defective plasmacytoid dendritic cells recruitment, but rather to the loss of an anti-inflammatory pathway involving ChemR23 expressed by non-leukocytic cells. The chemerin/ChemR23 system plays important roles in the physiopathology of viral pneumonia, and might therefore be considered as a therapeutic target for anti-viral and anti-inflammatory therapies.

Infections of the lower respiratory tract by single-stranded RNA viruses represent a major health problem worldwide. Animal models indicate that the severity of infections caused by these viruses is due essentially to an excessive primary immune response of the host, rather than the direct cytopathogenicity of the viruses. Plasmacytoid dendritic cells have been reported to play an important role in anti-viral immunity, but the factors responsible for the recruitment of these cells to the infected lung were unknown. This study depicts the roles of the G protein-coupled receptor ChemR23 in the recruitment of plasmacytoid dendritic cells and anti-viral immunity in a mouse model of acute viral pneumonia. The data also highlight the role of ChemR23 in dampening the lung inflammatory response. This latter effect is independent of pDC recruitment but involves non-leukocytic cells. This observation is of particular interest considering the established role of airway endothelial and epithelial cells in the immune responses following bacterial, viral and fungal infections. Our results suggest therefore that the chemerin/ChemR23 system might be considered as a target for anti-viral and anti-inflammatory therapies.

S100A2 level changes are related to human periodontitis

Periodontitis is an inflammatory disease, which, when severe, can result in tooth loss, that affects the quality of life. S100A2 was previously identified as a component of gingival crevicular fluid (GCF) via proteome analysis, but it has not been investigated whether S100A2 plays a role in periodontitis. In this study, we analyzed mRNA expression of S100A2 in gingival tissues from normal and classified periodontal disease patients and compared it to that of S100A8 and S100A9. Quantitative real time-PCR revealed that the mRNA expression levels of S100A2, S100A8, and S100A9 were significantly upregulated in gingival tissues with gingivitis, moderate periodontitis, and severe periodontitis compared to normal tissues. In addition, S100A2 proteins in GCF and the conditioned media of lipopolysaccharide (LPS)-treated Jurkat cells were confirmed by ELISA. S100A2 protein levels were significantly higher in GCF in gingivitis and moderate periodontitis groups than in normal groups. S100A2 mRNA expression and protein secretion were also increased by LPS stimulation. Based on the up-regulation of S100A2 in LPS-stimulated immune cells, gingival tissues and GCF from periodontal disease groups, we conclude that S100A2 is a functional component in the immune response during periodontitis and may serve as a potential biomarker for periodontitis.

The role of ChemR23 in the induction and resolution of cigarette smoke-induced inflammation

Chronic obstructive pulmonary disease is mainly triggered by cigarette smoke (CS) and progresses even after smoking cessation. CS induces an exaggerated influx of inflammatory cells to the bronchoalveolar space and lung parenchyma, likely resulting from a complex interplay between chemoattractants and their respective receptors. In a murine CS model of chronic obstructive pulmonary disease, we studied the importance of chemokine-like receptor ChemR23 for the induction and resolution of inflammation in CS-exposed lungs. Subacute and chronic CS exposure increased protein levels of the ChemR23 ligand and chemoattractant, chemerin, in bronchoalveolar lavage (BAL) fluid of wild-type (WT) mice. Moreover, the proinflammatory chemokines CXCL1, CCL2, and CCL20 were increased in the airways of CS-exposed WT mice, accompanied by a massive accumulation of inflammatory neutrophils and monocytes, CD11b(hi)CD103(-) and CD11b(lo)CD103(+) dendritic cells (DCs), and CD4(+) and CD8(+) T cells. The lung parenchyma of WT mice was infiltrated with inflammatory neutrophils, CD11b(hi)CD103(-) DCs, and activated CD4(+) T cells after CS exposure. CS-induced inflammation was severely attenuated in BAL fluid and lungs of ChemR23 knockout mice with regard to the induction of inflammatory chemokines and the recruitment of inflammatory cells. Neutrophils and CD8(+) T cells persisted in the airways of WT mice, as did the airway-derived conventional DCs in the mediastinal lymph nodes, for at least 14 d after smoking cessation. In the BAL fluid of CS-exposed ChemR23 knockout mice, there was a remarkable delayed accumulation of T cells 14 d after the final exposure. Our data support a role for ChemR23 in directing innate and adaptive immune cells to CS-exposed lungs.

[Alteration of tazarotene induced gene-2 expression in psoriasis vulgaris]

OBJECTIVE

To investigate the role of tazarotene induced gene-2 (TIG2) in psoriasis vulgaris.

METHODS

TIG2 protein and mRNA expressions in normal tissues, psoriatic lesions and uninvolved skin tissues were detected by immunohistochemistry and in situ hybridization, respectively.

RESULTS

TIG2 protein and mRNA were expressed in all the layers of normal and uninvolved epidermis. TIG2 expression was detected in the upper layers of the stratum spinosum of the marginal region of the psoriatic lesions, but not in the central area of the lesions. TIG2 expression was significantly lower in the basal layers of the central area of the paoriasis than that in the normal skin and uninvolved tissues (P < 0.01), and also lower in the marginal regions of the lesions (P < 0.01).The suprabasal layers of the marginal region in the lesion showed significantly lower TIG2 expression than the central area of the lesion (P < 0.01).

CONCLUSION

TIG2 may maintain the normal differentiation of epidermal keratinocytes and implicate in the pathogenesis and development of psoriasis vulgaris.

The prognostic value of Stathmin-1, S100A2, and SYK proteins in ER-positive primary breast cancer patients treated with adjuvant tamoxifen monotherapy: an immunohistochemical study

INTRODUCTION

We recently found that DNA methylation of S100A2, spleen tyrosine kinase (SYK), and Stathmin-1 (STMN1) correlates with response to tamoxifen therapy in metastatic breast cancer. In this retrospective study, we investigated immunohistochemically whether these three markers are predictors of relapse in early breast cancer (EBC) patients treated with adjuvant tamoxifen alone.

METHODS

Immunohistochemical staining was performed for S100A2, SYK and STMN1 on a tissue microarray containing ER-positive invasive breast carcinomas from a study cohort of 215 operable breast cancer patients, who underwent radical local therapy and who were treated with adjuvant tamoxifen monotherapy. Cox regression was used to correlate staining intensity of the three markers with main endpoints in our study; disease-free survival (DFS), and disease-specific survival (DSS).

RESULTS

In univariate analysis, only STMN1 staining intensity strongly correlated with DFS (P = 0.014) and DSS (P = 0.002). In the groups of low and high STMN1 intensity, DFS was 84% and 63%, and DSS was 89% and 70%. STMN1 retained its prognostic value for DFS (P = 0.002) and DSS (<0.001) in the multivariate model together with lymph node status. We found also a trend to better DFS in patients with low STMN1 intensity in both lymph node-positive (P = 0.001) and -negative patients (P = 0.065). As the tumour cells did not express S100A2 (except in one case) the potential prognostic value of this marker was not evaluated.

CONCLUSIONS

Staining intensity of STMN1, but not SYK, predicted outcome in our collective of ER- positive tamoxifen treated EBC patients.

Enzymatic digestion of the milk protein beta-casein releases potent chemotactic peptide(s) for monocytes and macrophages

Proteins in the milk release biologically active peptides upon enzymatic digestion. In the present study, we report the identification of novel monocyte/macrophage chemotactic peptides derived from enzymatically digested bovine beta-casein, a casein family member that is a major constituent of milk. Beta-casein fragments generated by actinase E showed potent chemotactic activity for human and mouse monocytes/macrophages, but not neutrophils, T lymphocytes or dendritic cells. The fragment-induced migration of human monocytes was inhibited by pertussis toxin and was not desensitized by a variety of known chemoattractants, suggesting that the digests activate a unique G protein-coupled receptor(s). The digests were further fractionated and purified to yield 3 small peptides. One peptide Q1 designated as "beta-casochemotide-1" with the amino acid sequence of YPVEP (f114-118 of beta-casein) induced high levels of macrophage chemotaxis. It also promoted calcium mobilization in macrophages, another indication of cell activation. Our study suggests that biologically active peptides released by actinase-digested milk beta-casein may promote innate host immune responses by inducing macrophage migration and activation.

[Study of the mechanism of mast cell increase in cellular leiomyoma of uterus]

OBJECTIVE

To study the mechanism of mast cell increase in cellular leiomyoma of uterus.

METHODS

Tissue sections from 30 cases of cellular leiomyoma of uterus, 15 cases of leiomyosarcoma and 30 cases of ordinary leiomyoma were studied using immunohistochemical double labeling techniques. The expression of mast cell tryptase and Ki-67 as well as mast cell tryptase and chemotactic factors RANTES, Eotaxin, monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-beta (TGF-beta) were double immunostained.

RESULTS

Ki-67 in mast cells was rarely expressed in each group. Expressions of regulate upon activation normal T cell expressed and secreted (RANTES), Eotaxin and TGF -beta in cellular leiomyoma were 78%, 89%, 91%, respectively. They were all higher than those in ordinary leiomyoma and leiomyosarcoma (P < 0.01), which were 60%, 81%, 86% and 39%, 44%, 59%, respectively. There were positive correlations between RANTES and the number of mast cells (r = 0.655, P < 0.01) as well as between Eotaxin and the number of mast cells (r = 0.543, P < 0.01). However, expression of MCP-1 was not observed in tumor cells in any group.

CONCLUSIONS

Mast cell increase in cellular leiomyoma of the uterus is due to local recruitment of mast cells. RANTES and Eotaxin secreted by smooth muscle tumor cells correlates with the recruitment of mast cells, but MCP-1 and TGF-beta do not.

The myeloid differentiation factor 88 is dispensable for the development of a delayed host response to Pseudomonas aeruginosa lung infection in mice

Because MyD88 transduces a core set of Toll-like receptor (TLR)-induced signals, microbial-induced host responses can be divided broadly into the MyD88-dependent and MyD88-independent pathways. A specific pathogen induces a distinct pattern of host response dependent upon the signalling pathways employed. Recently, we demonstrated that a MyD88-dependent pathway is essential for the development of early (4-8 h) host response to Pseudomonas aeruginosa lung infection. Here, we show that the development of a delayed (24-48 h) host response to P. aeruginosa is independent of MyD88. Using MyD88-deficient mice, the production of macrophage inflammatory protein 2, tumour necrosis factor and interleukin 1alpha in the airway was observed following P. aeruginosa lung infection for 24 or 48 h. Moreover, the MyD88-deficient mice recruited sufficient neutrophils in the lung and cleared the bacteria efficiently from the lung after 48 h. Thus, the full development of host responses to P. aeruginosa lung infection involves, in a sequential, stepwise fashion, a MyD88-dependent early response and a MyD88-independent delayed mechanism.

Coronary collateral function long after drug-eluting stent implantation

OBJECTIVES

This study was designed to compare coronary collateral function in patients after bare-metal stent (BMS) or drug-eluting stent (DES) implantation.

BACKGROUND

Drug-eluting stents have an inhibitory effect on the production of cytokines, chemotactic proteins, and growth factors, and may therefore negatively affect coronary collateral growth.

METHODS

A total of 120 patients with long-term stable coronary artery disease (CAD) after stent implantation were included. Both the BMS group and the DES group comprised 60 patients matched for in-stent stenosis severity of the vessel undergoing collateral flow index (CFI) measurement at follow-up and for the duration of follow-up. The primary end point of the investigation was invasively determined coronary collateral function 6 months after stent implantation. Collateral function was assessed by simultaneous aortic, coronary wedge, and central venous pressure measurements (yielding CFI) and by intracoronary electrocardiogram during balloon occlusion.

RESULTS

There were no differences between the groups regarding age, gender, body mass index, frequency of cardiovascular risk factors, use of cardiovascular drugs, severity of CAD, or site of coronary artery stenoses. Despite equal in-stent stenosis severity (46 +/- 34% and 45 +/- 36%) and equal follow-up duration (6.2 +/- 10 months and 6.5 +/- 5.4 months), CFI was diminished in the DES versus BMS group (0.154 +/- 0.097 vs. 0.224 +/- 0.142; p = 0.0049), and the rate of collaterals insufficient to prevent ischemia during occlusion (intracoronary electrocardiographic ST-segment elevation > or =0.1 mV) was higher with 50 of 60 patients in the DES group and 33 of 60 patients in the BMS group (p = 0.001).

CONCLUSIONS

Collateral function long after coronary stenting is impaired with DES (sirolimus and paclitaxel) when compared with BMS. Considering the protective nature of collateral vessels, this could lead to more serious cardiac events in the presence of an abrupt coronary occlusion.

Regulatory mechanisms of galectin-9 and eotaxin-3 synthesis in epidermal keratinocytes: possible involvement of galectin-9 in dermal eosinophilia of Th1-polarized skin inflammation

BACKGROUND

Skin eosinophilia is a common feature of allergic skin diseases, but it is unclear how epidermal and dermal eosinophil infiltration is controlled. To investigate regulation of localization of eosinophils in skin, we examined the regulatory mechanisms of expression of eosinophil-specific chemoattractants in dermal fibroblasts and epidermal keratinocytes.

METHODS

We analyzed production of eotaxin, eotaxin-2, eotaxin-3 and galectin-9 by dermal fibroblasts and epidermal keratinocytes in response to several stimuli in vitro.

RESULTS

Dermal fibroblasts produced eotaxin and eotaxin-3 in response to stimulation by interleukin (IL)-4 and/or tumor necrosis factor-alpha. Similarly, IL-4 stimulated epidermal keratinocytes to secrete eotaxin-3. However, we did not detect eotaxin mRNA expression or protein secretion by keratinocytes stimulated in vitro. Interferon (IFN)-gamma induced galectin-9 expression on dermal fibroblasts. Conversely, expression of galectin-9 on epidermal keratinocytes was dose-dependently inhibited by IFN-gamma. The immunohistochemical assays revealed that dermal fibroblasts (but not epidermal keratinocytes) in the lesional skin of psoriasis vulgaris (a Th1-polarized disease) express significant levels of galectin-9.

CONCLUSION

Eotaxin-3 contributes to dermal and epidermal eosinophil infiltration in Th2-polarized skin inflammation in which IL-4 is produced. In contrast, IFN-gamma-dominated inflammation appears to mediate eosinophil extravasation into the dermis and eosinophil adhesion to dermal fibroblasts via galectin-9 in association with decreased chemoattractant activity of epidermal galectin-9. The present results reveal a novel mechanism of dermal eosinophilia in IFN-gamma-mediated skin inflammation, and reflect concerted chemoattractant production involving dermal and/or epidermal eosinophilia during changes in the local cytokine profile.

[Expression of S100A2 in secondarily radioresistant pancreatic cancer cells and significance thereof]

OBJECTIVE

To investigate the association of S100A2 expression with the secondary radioresistance in pancreatic cancer cells.

METHODS

Human pancreatic cancer cells of the line SW1990, parental line, and the secondarily radioresistant human pancreatic cancer cells of the line SW1990/R were cultured and inoculated into the wells of a 6-well plate. 5-Aza-2'-deoxycytidine (5-aza-DC) of different concentrations was added into the culture fluid. Forty-eight hours later X-ray irradiation was conducted. Cloning efficiency assay was used to assess the cell survival. The cell cycle was analyzed by flow cytometry. The mRNA expression of S100A2 was examined by real-time RT-PCR and the protein expression of S100A2 was examined by immunofluorescence quantitative analysis.

RESULTS

The S100A2 mRNA expression level of the SW1990 line was significantly higher than that of the SW1990/R line. Treated by 5-aza-dC, the S100A2 mRNA expression level of the SW1990/R line increased by 2 approximately 3 times. The S100A2 protein expression level of the SW1990 line was significantly higher than that of the SW1990/R line (t = 3.648, P = 0.022). Treated by 5-aza-dC, the S100A2 protein expression level of the SW1990/R line increased, by 5 times at most (t = -11.404, P = 0.001). The G(2)/M of the SW1990 line was 16.2%, significantly higher than that of the SW1990/R line (16.2%), and the G(2)/M levels of the SW1990/R line treated by 5-aza-dC of different concentrations were all increased dose-dependently. The colony-forming rates of the SW1990/R line of the 5-aza-dC + irradiation groups were all significantly lower than that of the SW1990/R line of the pure irradiation group, even the dose of 5-aza-dC was as low as 0.025 microm. The SF2 (cell survival rate with the irradiation dose of 2 Gy) of the 5-aza-dC + irradiation group was 0.122, significantly lower than that of the pure irradiation group (0.460).

CONCLUSION

The expression level of S100A2 is low in the radioresistant pancreatic cancer cells, which may be one of the mechanisms of radioresistance of these cells.

Sivelestat reduces inflammatory mediators and preserves neutrophil deformability during simulated extracorporeal circulation

BACKGROUND

Neutrophil is a major focus in efforts to ameliorate the systemic inflammatory response associated with cardiopulmonary bypass. Neutrophil elastase is a powerful proteolytic enzyme, and plays a pivotal role in the development of the inflammatory response. This study assesses the inhibitory effects of sivelestat, a highly specific neutrophil elastase inhibitor, on elastase levels, cytokine production, and the functional changes of neutrophils in a simulated extracorporeal circulation model.

METHODS

Simulated recirculation was established by recirculating heparinized (3.75 U/mL) human blood for 120 minutes in an oxygenator and a roller pump circuit with and without 100 micromol/L of sivelestat (n = 7 for each group). Neutrophil elastase and interleukin-8 were measured with an enzyme immunoassay. Neutrophil deformability was evaluated by simulated microcapillaries. The neutrophil F-actin and the expression of CD11b and L-selectin were measured by flow cytometry.

RESULTS

Sivelestat reduced both neutrophil elastase levels (p = 0.0006) and interleukin-8 production (p < 0.0001) at 120 minutes of recirculation. Sivelestat also significantly preserved neutrophil deformability (p = 0.017) and reduced F-actin expression (p = 0.0037). The drug did not modulate the changes of CD11b or L-selectin.

CONCLUSIONS

This study suggests that specific elastase inhibition with sivelestat could be a feasible therapeutic strategy for patients undergoing cardiopulmonary bypass to attenuate neutrophil-derived inflammatory response and organ injuries.

A selective COX-2 inhibitor suppresses chronic pancreatitis in an animal model (WBN/Kob rats): significant reduction of macrophage infiltration and fibrosis

INTRODUCTION

Therapeutic strategies to treat chronic pancreatitis (CP) are very limited. Other chronic inflammatory diseases can be successfully suppressed by selective cyclooxygenase 2 (COX-2) inhibitors. As COX-2 is elevated in CP, we attempted to inhibit COX-2 activity in an animal model of CP (WBN/Kob rat). We then analysed the effect of COX-2 inhibition on macrophages, important mediators of chronic inflammation.

METHODS

Male WBN/Kob rats were continuously fed the COX-2 inhibitor rofecoxib, starting at the age of seven weeks. Animals were sacrificed 2, 5, 9, 17, 29, 41, and 47 weeks later. In some animals, treatment was discontinued after 17 weeks, and animals were observed for another 24 weeks.

RESULTS

Compared with the spontaneous development of inflammatory injury and fibrosis in WBN/Kob control rats, animals treated with rofecoxib exhibited a significant reduction and delay (p<0.0001) in inflammation. Collagen and transforming growth factor beta synthesis were significantly reduced. Similarly, prostaglandin E(2) levels were markedly lower, indicating strong inhibition of COX-2 activity (p<0.003). If treatment was discontinued at 24 weeks of age, all parameters of inflammation strongly increased comparable with that in untreated rats. The correlation of initial infiltration with subsequent fibrosis led us to determine the effect of rofecoxib on macrophage migration. In chemotaxis experiments, macrophages became insensitive to the chemoattractant fMLP in the presence of rofecoxib.

CONCLUSION

In the WBN/Kob rat, chronic inflammatory changes and subsequent fibrosis can be inhibited by rofecoxib. Initial events include infiltration of macrophages. Cell culture experiments indicate that migration of macrophages is COX-2 dependent.

FGF as a Target-Derived Chemoattractant for Developing Motor Axons Genetically Programmed by the LIM Code

LIM transcription factors confer developing axons with specific navigational properties, but the downstream guidance receptors and ligands are not well defined. The dermomyotome, a transient structure from which axial muscles arise, is the source of a secreted long-range chemoattractant specific for medial-class spinal motor neuron axons (MMCm axons). We show that fibroblast growth factors (FGFs) produced by the dermomyotome selectively attract MMCm axons in vitro. FGF receptor 1 (FGFR1) expression is restricted to MMCm neurons, and conditional deletion of FGFR1 causes motor axon guidance defects. Furthermore, reprogramming the identity of limb-innervating motor neurons to that of dermomyotome-innervating MMCm cells using the LIM factor Lhx3 induces FGFR1 expression and shifts an increased number of motor axons to an FGF-responsive state. These results point to a role for FGF signaling in axon guidance and further unravel how downstream effectors of LIM codes direct wiring of the developing nervous system.

The role of S100A6 in pancreatic cancer development and its clinical implication as a diagnostic marker and therapeutic target

Recent microarray analyses showed that the S100 family contains members that are candidate diagnostic markers or therapeutic targets. In the present study, to evaluate the involvement of S100A6 in pancreatic cancer and its clinical usefulness for diagnosis, we examined S100A6 mRNA expression in pancreatic tissues and pancreatic juice from patients with different pancreatic diseases. To investigate the role of S100A6 in carcinogenesis of pancreatic cancer and the potential of S100A6 as a diagnostic marker for early detection of pancreatic cancer, we did immunohistochemistry and microdissection-based mRNA analysis of pancreatic normal ducts, pancreatic intraepithelial neoplasias, and invasive ductal carcinomas. We also used in vitro experiments and microarray analysis with RNA interference to evaluate the functional role of S100A6 and its potential as a therapeutic target for pancreatic cancer. S100A6 mRNA levels were significantly higher in carcinoma specimens than in nonneoplastic tissues. In pancreatic juice, there was a significant difference in S100A6 expression between patients with carcinoma and those with nonneoplastic disease. Receiver operating characteristic curves revealed that S100A6 might be a useful marker for diagnosis of pancreatic cancer. Immunohistochemistry and microdissection-based analysis showed differential expression of S100A6 among normal ducts, pancreatic intraepithelial neoplasias, and invasive ductal carcinomas. In vitro data showed that inhibition of S100A6 decreased proliferation and invasiveness of cancer cells, and these findings were supported by microarray data. Our present results suggest that quantitation of S100A6 mRNA is a promising tool for diagnosis of pancreatic cancer, and that S100A6 may be a promising therapeutic target for pancreatic cancer.

Role of metallothionein in coagulatory disturbance and systemic inflammation induced by lipopolysaccharide in mice

Although metallothionein (MT) can be induced by inflammatory mediators, its roles in coagulatory disturbance during inflammation are poorly defined. We determined whether MT protects against coagulatory and fibrinolytic disturbance and systemic inflammation induced by intraperitoneal administration of lipopolysaccharide (LPS) in MT-I/II null (-/-) and wild-type (WT) mice. As compared with WT mice, MT (-/-) mice revealed significant prolongation of prothrombin and activated partial thromboplastin time, a significant increase in the levels of fibrinogen and fibrinogen/fibrin degradation products, and a significant decrease in activated protein C, after LPS treatment. LPS induced inflammatory organ damages in the lung, kidney, and liver in both genotypes of mice. The damages, including neutrophil infiltration, were more prominent in MT (-/-) mice than in WT mice after LPS treatment. In both genotypes of mice, LPS enhanced protein expression of interleukin (IL)-1beta, IL-6, granulocyte/macrophage-colony-stimulating factor, macrophage inflammatory protein (MIP)-1alpha, MIP-2, macrophage chemoattractant protein-1, and keratinocyte chemoattractant in the lung, kidney, and liver and circulatory levels of IL-1beta, IL-6, MIP-2, and KC. In overall trends, however, the levels of these proinflammatory proteins were greater in MT (-/-) mice than in WT mice after LPS challenge. Our results suggest that MT protects against coagulatory and fibrinolytic disturbance and multiple organ damages induced by LPS, at least partly, via the inhibition of the expression of proinflammatory proteins.

S100A2 expression as a predictive marker for late cervical metastasis in stage I and II invasive squamous cell carcinoma of the oral cavity

The purpose of this study was to discover whether S100A2 expression is associated with late cervical metastasis in patients with stage I and II invasive squamous cell carcinoma of the oral cavity. We retrospectively investigated the clinicopathological parameters and S100A2 expression in surgical specimens taken from 52 patients with T1-2N0M0 invasive squamous cell carcinoma of the oral cavity (OSCC) who had not undergone elective neck dissection or irradiation to the neck. All of the clinicopathological factors and S100A2 expression were compared in terms of late cervical metastasis. In univariate analysis, late cervical metastasis correlated with poor overall survival. A higher rate of late cervical metastasis was observed in patients with S100A2-negative tumors than those with S100A2-positive tumors. Multivariate analysis on late cervical metastasis revealed that S100A2 expression was demonstrated to be the only independent factor for late cervical metastasis. Our results indicate that patients with stage I or II invasive OSCC without S100A2 expression should be considered a high-risk group for late cervical metastasis when a wait-and-see policy for the neck is being considered.

Promoter hyper-methylation of calcium binding proteins S100A6 and S100A2 in human prostate cancer

BACKGROUND

S100A6 and S100A2 are members of the S100 family of calcium binding proteins, which are down regulated in prostate cancer, however the molecular mechanism(s) underlying their loss of expression is unknown.

METHODS

The promoter and exon 1 region of the S100A6 and S100A2 genes was sequenced in bisulfite modified DNA from non-malignant, benign prostatic hyperplasia (BPH), malignant and metastatic prostate tissues and in cell lines. Immunohistochemistry was performed to correlate S100A2 expression with methylation status.

RESULTS

S100A6 methylation was absent or occurred at isolated sites in 14/14 cases of non-malignant epithelium and 5/5 cases of BPH tissues, whereas methylation was seen in 14/27 (52%) cases of prostatic cancer (P<0.0001), 2/2 cases of metastatic cancer and in the CWR22 prostatic cancer xenograft. Critical CpG sites within the S100A2 promoter were methylated in LNCaP, LNCaP-LN3, and CWR22 cells but not in Du145, PC3 or BPH45 cells. In tissues, S100A2 methylation was seen in 32/34 (94%) cases of adenocarcinoma and 5/5 cases of metastatic cancer. However, S100A2 methylation was also seen in 9/12 (75%) cases of non-malignant tissues and in 5/5 cases of BPH. Immunostaining, showed absent S100A2 expression all 41 cases of prostatic cancer, whereas staining was seen in the basal cells of non-malignant epithelium.

CONCLUSIONS

Loss of S100A6 and S100A2 proteins is frequent in human prostatic cancer. A major mechanism underlying the loss of S100A6 expression appears to involve promoter hyper-methylation. However, mechanisms other than methylation of the known promoter are involved in silencing S100A2 in the prostate.

Establishment of an immortalized cell line from a precancerous lesion of lung adenocarcinoma, and genes highly expressed in the early stages of lung adenocarcinoma development

Atypical adenomatous hyperplasia (AAH) is classified as a precancerous lesion of lung adenocarcinoma. We established an immortalized AAH cell line (PL16T) and a human non-neoplastic bronchial epithelial cell line (PL16B) from the same patient by transfection with the gene for SV40 large T antigen. The expression profile of PL16T was compared with that of PL16B by the suppression subtractive hybridization method. From 704 selectively hybridized clones, we finally selected 25 fragments of mRNA that showed transcription levels more than three times higher in PL16T than in PL16B. Thirteen (52%) and eight (32%) of them encoded tumor-associated calcium signal transducer 2 (TACSTD2) and S100 calcium binding protein A2 (S100A2), respectively. The high transcription of TACSTD2 and S100A2 in PL16T was confirmed by in situ hybridization. In normal lung tissue, both TACSTD2 and S100A2 were expressed at very low levels, but seven and five of 14 AAH were positive for TACSTD2 and S100A2, respectively. The frequency of TACSTD2 positivity was increased in 16 of 22 bronchioloalveolar carcinomas (BAC) and adenocarcinoma with mixed subtype with BAC component (mixed BAC). Positivity for S100A2 occurred in four of 22 BAC and mixed BAC. The abnormal transcription of TACSTD2 and S100A2 are thought to be unique molecular markers of the preinvasive stage of lung adenocarcinoma.

Involvement of phospholipase A2 in Pseudomonas aeruginosa-mediated PMN transepithelial migration

Inflammation resulting from bacterial infection of the respiratory mucosal surface during pneumonia and cystic fibrosis contributes to pathology. A major consequence of the inflammatory response is recruitment of polymorphonuclear cells (PMNs) to the infected site. To reach the airway, PMNs must travel through several cellular and extracellular barriers, via the actions of multiple cytokines, chemokines, and adhesion molecules. Using a model of polarized lung epithelial cells (A549 or Calu-3) grown on Transwell filters and human PMNs, we have shown that Pseudomonas aeruginosa induces PMN migration across lung epithelial barriers. The process is mediated by epithelial production of the eicosanoid hepoxilin A(3) (HXA(3)) in response to P. aeruginosa infection. HXA(3) is a PMN chemoattractant metabolized from arachidonic acid (AA). Given that release of AA is believed to be the rate-limiting step in generating eicosanoids, we investigated whether P. aeruginosa infection of lung epithelial cells resulted in an increase in free AA. P. aeruginosa infection of A549 or Calu-3 monolayers resulted in a significant increase in [(3)H]AA released from prelabeled lung epithelial cells. This was partially inhibited by PLA(2) inhibitors ONO-RS-082 and ACA as well as an inhibitor of diacylglycerol lipase. Both PLA(2) inhibitors dramatically reduced P. aeruginosa-induced PMN transmigration, whereas the diacylglycerol lipase inhibitor had no effect. In addition, we observed that P. aeruginosa infection caused an increase in the phosphorylation of cytosolic PLA(2) (cPLA(2)), suggesting a mechanism whereby P. aeruginosa activates cPLA(2) generating free AA that may be converted to HXA(3), which is required for mediating PMN transmigration.

Expression of S100A2 and S100A6 in thyroid carcinomas

AIMS

S100 calcium-binding proteins are known to play multiple roles in carcinoma development. In this study, we focused on two kinds of these proteins, S100A2 and S100A6, and investigated their expression in thyroid neoplasms.

METHODS AND RESULTS

We investigated S100A2 and S100A6 expression in 141 thyroid neoplasms by immunohistochemistry. S100A2 was not expressed in normal follicles or follicular tumours, with one exception. Although 89.5% of papillary carcinoma were positive for S100A2, the expression was heterogeneous except in two cases. In anaplastic carcinoma, 78.5% of cases expressed S100A2 diffusely, while the remaining cases were negative. In normal follicles, S100A6 expression was always low, while 8.3% of follicular adenomas and 39.5% of follicular carcinomas showed increased expression. In papillary carcinomas, S100A6 expression was increased in 75% of cases, but in anaplastic carcinomas it was decreased, with only 14.3% showing high expression.

CONCLUSIONS

The expression patterns of S100A2 and S100A6 in thyroid neoplasms are unique compared with those of other carcinomas, suggesting that: (i) S100A2 and S100A6 contribute to certain events in papillary carcinoma progression, and (ii) S100A2 expression is one of the biological characteristics of anaplastic carcinoma.

Biochemistry, biology and chemistry of the 5-lipoxygenase product 5-oxo-ETE

5-Oxo-ETE (5-oxo-6,8,11,14-eicosatetraenoic acid) is an arachidonic acid metabolite formed by the oxidation of 5S-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE) by 5-hydroxyeicosanoid dehydrogenase (5-HEDH), a microsomal enzyme found in leukocytes and platelets. 5-HEDH is highly selective for 5S-HETE, and displays little activity for other monohydroxy metabolites of arachidonic acid. The synthesis of 5-oxo-ETE requires NADP(+) and can be stimulated by activation of the respiratory burst and by oxidative stress. 5-Oxo-ETE is a chemoattractant for eosinophils and neutrophils, and elicits a variety of responses in these cells, including actin polymerization, calcium mobilization, integrin expression, and degranulation. Its primary target appears to be the eosinophil, and among lipid mediators it is the strongest chemoattractant for these cells. It is also a chemoattractant for monocytes and stimulates the proliferation of prostate tumor cells. Its actions are mediated by a G(i) protein-coupled receptor (OXE receptor) that is highly expressed by eosinophils>neutrophils>monocytes. When administered in vivo in both humans and rodents it elicits tissue eosinophilia, suggesting that it may be an important mediator in allergic diseases such as asthma, and that the development of drugs designed to prevent its formation or effects may be useful therapeutic agents in these diseases.

Role of ChemR23 in directing the migration of myeloid and plasmacytoid dendritic cells to lymphoid organs and inflamed skin

Chemerin is a chemotactic agent that was recently identified as the ligand of ChemR23, a serpentine receptor expressed by activated macrophages and monocyte-derived dendritic cells (DCs). This paper shows that blood plasmacytoid and myeloid DCs express functional ChemR23. Recombinant chemerin induced the transmigration of plasmacytoid and myeloid DCs across an endothelial cell monolayer. In secondary lymphoid organs (lymph nodes and tonsils), ChemR23 is expressed by CD123⁺ plasmacytoid DCs and by CD1a⁺ DC-SIGN⁺ DCs in the interfollicular T cell area. ChemR23⁺ DCs were also observed in dermis from normal skin, whereas Langerhans cells were negative. Chemerin expression was selectively detected on the luminal side of high endothelial venules in secondary lymphoid organs and in dermal endothelial vessels of lupus erythematosus skin lesions. Chemerin⁺ endothelial cells were surrounded by ChemR23⁺ plasmacytoid DCs. Thus, ChemR23 is expressed and functional in plasmacytoid DCs, a property shared only by CXCR4 among chemotactic receptors. This finding, together with the selective expression of the cognate ligand on the luminal side of high endothelial venules and inflamed endothelium, suggests a key role of the ChemR23/chemerin axis in directing plasmacytoid DC trafficking.

Overexpression of S100A2 protein as a prognostic marker for patients with stage I non small cell lung cancer

S100A2, a calcium-binding protein, recently became of major interest because of its differential expression during transformation and metastasis in various tumors. The purpose of this study was to investigate the prognostic significance of S100A2 expression in the early-stage non small lung cancer (NSCLC). Immunohistochemical analysis to determine the percentage of cells staining positive for S100A2 was performed on 11 NSCLC tissue microarray slides containing samples from 113 patients with pathologic stage I NSCLC who had undergone curative surgery. S100A2 was expressed in samples from 79 patients (69.9%). Kaplan-Meier analysis showed that patients whose tumors had positive S100A2 expression had a significantly lower overall survival and disease-specific survival rate at 5 years after surgery than did patients with negative S100A2 expression (p < 0.001 and p < 0.001, respectively). Age at diagnosis, histologic type of cancer, degree of differentiation and smoking history did not have a statistically significant effect on survival. Multivariate analysis confirmed that S100A2 expression is a better predictor for disease-specific survival than were other clinical and histologic variables tested. Our results suggested that the expression of the S100A2 protein in stage I NSCLC indicates poor prognosis and may be used to identify patients with early-stage NSCLC who might benefit from adjuvant treatment.

Lipoteichoic acid from Staphylococcus aureus is a potent stimulus for neutrophil recruitment

Lipoteichoic acid (LTA) is a major immunostimulatory principle of Gram-positive bacteria. Intranasal application of LTA from S. aureus to mice resulted in greatly increased neutrophil and macrophage counts in the bronchoalveolar lavage as well as increased levels of the chemokine KC. The potential of highly pure, bioactive LTA from S. aureus to induce neutrophil recruitment and activation was investigated further in the human system. Although neutrophils expressed the key known receptors, CD14, TLR2 and TLR6, LTA did not induce or prime neutrophils for oxidative burst, or release of chemokines, bactericidal permeability-increasing protein or myeloperoxidase. However, LTA induced a strong release of the chemoattractants LTB4, IL-8, C5a, MCP-1 and the colony-stimulating factor G-CSF in whole blood comparable to stimulation with the same concentration of LPS (S. abortus equi). Further, the cytokine and chemoattractant pattern induced by LTA correlated well with that induced by live S. aureus of the same strain. LTA does not appear to activate neutrophils directly, but is a strong stimulus for the recruitment of phagocytes to the site of infection.

Synovial fibroblasts from patients with rheumatoid arthritis, like fibroblasts from Graves' disease, express high levels of IL-16 when treated with Igs against insulin-like growth factor-1 receptor

We have reported recently that IgG from patients with Graves' disease (GD) can induce the expression of the CD4-specific T lymphocyte chemoattractant, IL-16, and RANTES, a C-C chemokine, in their fibroblasts. This induction is mediated through the insulin-like growth factor-1 receptor (IGF-1R) pathway. We now report that Abs from individuals with active rheumatoid arthritis (RA-IgG) stimulate in their synovial fibroblasts the expression of these same cytokines. IgG from individuals without known autoimmune disease fails to elicit this chemoattractant production. Furthermore, RA-IgG fails to induce IL-16 or RANTES expression in synovial fibroblasts from donors with osteoarthritis. RA-IgG-provoked IL-16 and RANTES production also appears to involve the IGF-1R because receptor-blocking Abs prevent the response. RA fibroblasts transfected with a dominant-negative mutant IGF-1R fail to respond to RA-IgG. IGF-1 and the IGF-1R-specific analog Des(1-3) also induce cytokine production in RA fibroblasts. RA-IgG-provoked IL-16 expression is inhibited by rapamycin, a specific macrolide inhibitor of the Akt/FRAP/mammalian target of rapamycin/p70(s6k) pathway, and by dexamethasone. GD-IgG can also induce IL-16 in RA fibroblasts, and RA-IgG shows similar activity in GD fibroblasts. Thus, IgGs from patients with RA, like those associated with GD, activate IGF-1R, and in so doing provoke T cell chemoattraction expression in fibroblasts, suggesting a potential common pathway in the two diseases. Immune-competent cell trafficking to synovial tissue is integral to the pathogenesis of RA. Recognition of this novel RA-IgG/fibroblast interaction and its functional consequences may help identify therapeutic targets.

Estrogen Modulates Inflammatory Mediator Expression and Neutrophil Chemotaxis in Injured Arteries

BACKGROUND

We have previously shown that estrogen (17beta-estradiol; E2) inhibits neointima formation and migration of leukocytes, particularly neutrophils, into rat carotid arteries after acute endoluminal injury. This study tested the hypothesis that E2 inhibits expression of adhesion molecules, chemokines, and proinflammatory cytokines in rat carotid arteries in the early hours after balloon injury, thus attenuating the stimulus for leukocyte entry and negatively modulating the injury response.

METHODS AND RESULTS

Ovariectomized (OVX) rats were randomly assigned to treatment with E2 or vehicle (V) and subjected to balloon injury of the right carotid artery. After 2, 6, and 24 hours, rats were euthanized, and both carotid arteries were processed for real-time reverse transcription-polymerase chain reaction (2 and 24 hours), ELISA (6 hours), or neutrophil chemotaxis assay (24 hours). Expression of mRNA for adhesion molecules (P-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1), chemoattractants (cytokine-induced neutrophil chemoattractant [CINC]-2beta and monocyte chemoattractant protein [MCP]-1), and proinflammatory cytokines (interleukin [IL]-1 and IL-6) was markedly increased (2 to 5000 times) in injured arteries of OVX+V rats at 2 hours and was reduced by 24 hours. E2 significantly attenuated expression of the proinflammatory mediators (by 60% to 80%) at 2 hours. ELISA confirmed injury-induced upregulation of neutrophil and monocyte/macrophage chemoattractants (CINC-2alpha, MCP-1) in OVX+V arteries and E2-induced inhibition of CINC-2alpha expression. E2 significantly (by 65%) inhibited neutrophil chemotactic activity of arterial homogenates.

CONCLUSIONS

E2 attenuates the early vascular injury response, at least in part, by negatively modulating proinflammatory mediator expression and the resultant chemotactic activity of injured vessels for neutrophils.

FcεRI engagement of Langerhans cell–like dendritic cells and inflammatory dendritic epidermal cell–like dendritic cells induces chemotactic signals and different T-cell phenotypes in vitro☆

BACKGROUND

Atopic dermatitis (AD) is a biphasic inflammatory skin disease characterized by an initial phase predominated by T(H)2 cytokines, which switches into a second T(H)1-dominated chronic phase. Thus far, the small number of FcepsilonRI-bearing Langerhans cells (LCs) and inflammatory dendritic epidermal cells (IDECs) in the epidermis of patients with AD has hampered a detailed functional analysis and limited our knowledge of these dendritic cells (DCs).

OBJECTIVE

We studied FcepsilonRI-mediated mechanisms of LCs and IDECs with the help of a novel in vitro model.

METHODS

Langerhans cell-like dendritic cells (LC-DCs) and inflammatory dendritic epidermal cell-like dendritic cells (IDEC-DCs) bearing FcepsilonRI have been generated from monocytes of the same atopic donor and compared functionally with LCs and IDECs isolated from the skin of patients with AD.

RESULTS

We found that FcepsilonRI-activated LC-DCs release chemotactic signals, and supernatants of FcepsilonRI-activated LC-DCs increase the migratory capacity of precursor cells of IDECs and naive T cells in vitro. FcepsilonRI-activated IDEC-DCs produce high amounts of proinflammatory cytokines and chemokines and might thereby amplify the inflammatory immune reaction in patients with AD. Furthermore, FcepsilonRI-activated IDEC-DCs prime naive T cells into IFN-gamma-producing T cells and release IL-12 and IL-18, which together might lead to the switch of the initial T(H)2-type immune response into a response of the T(H)1 type in vivo.

CONCLUSION

The present study provides evidence that FcepsilonRI-activated LC-DCs and IDEC-DCs contribute distinctly to the outcome of T-cell responses in vitro and might have implications for the biphasic nature of AD in vivo.

Positive selection during the diversification of class I vomeronasal receptor-like (V1RL) genes, putative pheromone receptor genes, in human and primate evolution

Vomeronasal receptors are the major receptors for pheromones in vertebrates, and five putative type 1 vomeronasal receptors (V1RL) have been identified in humans. The evolution of the V1RL1 gene in non-human primates, and patterns of selection on V1RL genes, were investigated. The presumed ortholog of V1RL1 was sequenced from 13 species of nonhuman primate, and in eight of these species V1RL1 was a pseudogene. Phylogenetic reconstructions reveal that V1RL1 pseudogene formation occurred independently in multiple primate lineages. Using maximum likelihood estimates of dN/dS ratios in PAML, we show that V1RL genes have evolved under neutral evolution in lineages in which they became a pseudogene. In contrast, among lineages in which V1RL genes contain an open reading frame, the majority of sites are under purifying selection and a minority are under significant positive selection. These results provide an interesting case where all three categories of selection can be teased apart in the same data set using maximum likelihood methods. The finding of positive selection on V1RL genes during primate evolution provides indirect support for the hypothesis that V1RL genes have a function in species-specific pheromone detection in primates.

HMG-CoA reductase inhibitor, fluvastatin, has cholesterol-lowering independent "direct" effects on atherosclerotic vessels in high cholesterol diet-fed rabbits

Recent clinical studies suggest that some of the beneficial effects of 3-hydroxy-3-metylglutaryl coenzyme A (HMG-CoA) reductase inhibitors on the incidence of myocardial infarctions and ischemic strokes may be through their non-cholesterol-lowering "direct" effects on atherosclerotic vessels. We designed this study to test the hypothesis that fluvastatin inhibits atheroma formation and increase plaque stability independent of cholesterol-lowering effects. Rabbits were fed 0.5% high-cholesterol diet for 12 weeks (progression phase) and then fed the high-cholesterol diet either containing or not containing fluvastatin 2mg/kg per day for additional 8 weeks (treatment phase). Rabbits fed normal diet were used as control. Plasma total and LDL-cholesterol concentrations did not differ during the treatment phase of the experiment. Atherosclerotic changes (plaque formation, lipid- and macrophage-rich intimal thickening, the increase in MCP-1, IL-8, TNF-alpha, IL-1beta, M-CSF, MMP-1, MMP-9, MMP-12, and ACE mRNA expression, and the increase in plasma MCP-1 levels) were observed in the high-cholesterol diet group (HC). All of these changes were less in the fluvastatin-treated group (HC+Flu) than in HC. There was no significant difference in aortic collagen (type I and type IV) mRNA expression between groups. Furthermore, fluvastatin increased the extracellular matrix content (collagen) and vascular smooth muscle cell composition in the atherosclerotic lesion, leading to the increase in plaque stability score (collagen+smooth muscle cell area)/(macrophage+lipid deposition area) in HC+Flu. Fluvastatin not only reduced atherogenesis but also to stabilized vulnerable atheromatous plaques in atherosclerotic rabbits, presumably through the macrophage recruitment and activation in the aortic lesion, at a low dose without cholesterol-lowering effects.

Induction of C-X-C chemokines, growth-related oncogene alpha expression, and epithelial cell-derived neutrophil-activating protein-78 by ML-1 (interleukin-17F) involves activation of Raf1-mitogen-activated protein kinase kinase-extracellular signal-regulated kinase 1/2 pathway

Neutrophil recruitment into the airway typifies pulmonary inflammation and is regulated through chemokine network, in which two C-X-C chemokines play a critical role. Airway epithelial cells and vein endothelial cells are major cell sources of chemokines. ML-1 (interleukin-17F) is a recently discovered cytokine and its function still remains elusive. In this report, we investigated the functional effect of ML-1 in the expression of growth-related oncogene (GRO)alpha and epithelial cell-derived neutrophil activating protein (ENA)-78. The results showed first that ML-1 induces, in time- and dose-dependent manners, the gene and protein expressions for both chemokines in normal human bronchial epithelial cells and human umbilical vein endothelial cells. Furthermore, selective mitogen-activated protein kinase kinase (MEK) inhibitors 2'-amino-3'-methoxyflavone (PD98059), 1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenylmercapto) butadiene (U0126), and Raf1 kinase inhibitor I partially inhibited Ml-1-induced GROalpha and ENA-78 production. In contrast, the combination of PD98059 and Raf1 kinase inhibitor I completely abrogated the chemokine production, whereas a protein kinase C inhibitor, 2-(1-(3-aminopropyl) indol-3-yl)-3-(1-methylindol-3-yl) maleimide, acetate (Ro-31-7549), and a phosphatidylinositol 3-kinase inhibitor, 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), did not affect their production. Together, these data indicates a role for Raf1-MEK-extracellular signal-regulated kinase 1/2 pathway in ML-1 induced C-X-C chemokine expression, suggesting potential pharmacological targets for modulation.

Differential interleukin-8 and nitric oxide production in epithelial cells induced by mucosally invasive and noninvasive Trypanosoma cruzi trypomastigotes

Trypanosoma cruzi metacyclic trypomastigotes (MT), but not blood form trypomastigotes (BFT), are highly mucosally infective. We investigated the abilities of MT and BFT to induce inflammation and/or intracellular killing activity within mucosal epithelia. BFT, but not MT, induced marked increases in interleukin-8, GRO-alpha, MCP-1, and nitric oxide production in HeLa and AGS cells, despite similar infectivities. MT may avoid induction of inflammation as an important biological mechanism facilitating mucosal invasion.

Liver inflammation during monocrotaline hepatotoxicity

Monocrotaline (MCT) is a pyrrolizidine alkaloid (PA) plant toxin that causes hepatotoxicity in humans and animals. Human exposure occurs from consumption of contaminated grains and herbal teas and medicines. Intraperitoneal injection (i.p.) of 300 mg/kg MCT in rats produced time-dependent hepatic parenchymal cell (HPC) injury beginning at 12 h. At this time, an inflammatory infiltrate consisting of neutrophils (PMNs) appeared in areas of hepatocellular injury, and activation of the coagulation system occurred. PMN accumulation was preceded by up-regulation of the PMN chemokines cytokine-induced neutrophil chemoattractant-1 (CINC-1) and macrophage inflammatory protein-2 (MIP-2) in the liver. The monocyte chemokine, monocyte chemoattractant protein-1 (MCP-1), was also upregulated. Inhibition of Kupffer cell function with gadolinium chloride (GdCl(3)) significantly reduced CINC-1 protein in plasma after MCT treatment but had no effect on hepatic PMN accumulation. Since inflammation can contribute to either pathogenesis or resolution of tissue injury, we explored inflammatory factors as a contributor to MCT hepatotoxicity. To test the hypothesis that PMNs contribute to MCT-induced HPC injury, rats were depleted of PMNs with a rabbit anti-PMN serum prior to MCT treatment. Anti-PMN treatment reduced hepatic PMN accumulation by 80% but had no effect on MCT-induced HPC injury or activation of the coagulation system. To test the hypothesis that Kupffer cells and/or tumor necrosis factor-alpha (TNF-alpha) are required for MCT-induced HPC injury, rats were treated with either GdCl(3) to inhibit Kupffer cell function or pentoxifylline (PTX) to prevent synthesis of TNF-alpha. Neither treatment prevented MCT-induced HPC injury. Results from these studies suggest that PMNs, Kupffer cells and TNF-alpha are not critical mediators of MCT hepatotoxicity. Accordingly, although inflammation occurs in the liver after MCT treatment, it is not required for HPC injury and possibly occurs secondary to hepatocellular injury.

Transcriptional profiling of targets for combination therapy of lung carcinoma with paclitaxel and mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor

A combination of paclitaxel (Taxol) and mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK/Erk) inhibitor represents a rational new approach to chemotherapy. We performed Affymetrix microarray analysis to understand the global effects of this combination in lung carcinoma. Genes involved in cell cycle control, apoptosis, adhesion, proliferation, invasion, and metastasis were modulated. We observed similar patterns of gene modulation in ovarian and melanoma cell lines, indicating the general applicability of these findings. Functional genomic analysis identified two genes as new targets of drug-induced tumor apoptosis. The MGSA/Gro1 gene, important in melanoma growth, was induced by paclitaxel and reduced by MEK inhibition. Blockage of paclitaxel-induced melanoma growth stimulatory activity significantly reduced melanoma growth. Additionally, the expression of topoisomerase III beta, which exhibited a clear pattern of gene reduction by a combination of the two drugs, was significantly increased (5.7-fold) in primary lung cancers but not adjacent tissues. These findings provide potential new biomarkers and gene targets for the development of improved cancer treatment.

CINC-1 is an acute-phase protein induced by focal brain injury causing leukocyte mobilization and liver injury

Following injury or infection, the liver releases acute-phase proteins (APP). After a severe focal injury, this systemic response can be excessive and may lead to multiorgan dysfunction (MODS). CINC-1 is a neutrophil chemoattractant, and we have now established that it also functions as an early APP after injury to the brain or to peripheral tissues. After induction of a focal inflammatory lesion in the brain, there is rapid hepatic and serum CINC-1 induction, which is associated with increases in neutrophil numbers within the liver and within the circulation. CINC-1-mediated recruitment of neutrophils to organs distant from the primary injury site may contribute to MODS. Indeed, we found that enzyme markers of liver tissue injury are increased in the serum following generation of a focal inflammatory lesion in the brain. Neutralization of CINC-1 in the periphery reversed brain-injury-induced neutrophil mobilization and inhibited recruitment of neutrophils to the brain and to the liver. Thus, a significant component of the hepatic acute-phase response is the release of chemokines by the liver, which act to amplify the inflammatory response and modulate the subsequent leukocytosis and secondary tissue damage. Hepatic CINC-1 synthesis following injury presents a novel focus for treatment of inflammation.

Expression and production of the CXC chemokine growth-related oncogene-alpha by human eosinophils

Eosinophils are seen together with neutrophils at sites of inflammation. However, their roles are not clear. In addition, eosinophils infiltrate tumor tissue in some neoplastic diseases. In this study, we show that large amounts of the neutrophil-activating CXC chemokine growth-related oncogene (GRO)-alpha can be produced by human eosinophils. Eosinophils showed presence of preformed GRO-alpha in the crystalloid-containing specific granules (190 pg/2 x 10(6) cells). During incubation, a strong increase in GRO-alpha gene expression was seen. At a low cell density, addition of TNF-alpha or IL-1 beta increased the production of GRO-alpha in eosinophils, which was not the case at a higher cell density. Eosinophils can produce TNF-alpha themselves, and neutralizing Abs against TNF-alpha significantly inhibited GRO-alpha production. This suggests that autocrine and paracrine effects from TNF-alpha can be important when up-regulating GRO-alpha gene expression. In contrast, IFN-gamma, a prototypic Th1-cytokine, down-regulated expression of GRO-alpha. This may be important during resolution of inflammation but also suggests different roles for eosinophils depending on the inflammatory context. Tumor-infiltrating eosinophils in Hodgkin's disease of the nodular sclerosing type are associated with a poor prognosis. Eosinophils from such tumor tissue showed an abundant expression of GRO-alpha. The GRO-alpha receptor CXCR2 was also detected in tumor tissue, proposing interactions between eosinophils and the tumor. Our findings suggest that eosinophils can promote inflammation through recruitment of CXCR2-bearing cells. In addition, this feature of the eosinophils indicates a role for these cells in the biology of certain tumors.

Thrombin and protease-activated receptor-1 agonists promote lipopolysaccharide-induced hepatocellular injury in perfused livers

Bacterial lipopolysaccharide (LPS) is a potent inflammatory agent capable of producing liver injury, the pathogenesis of which depends on numerous mediators, including thrombin. Previous studies showed that thrombin promotes LPS-induced liver injury independent of its ability to form fibrin clots. In isolated, buffer-perfused livers from LPS-treated rats, thrombin added to the perfusion buffer caused dose-dependent liver injury with an EC(50) value of 0.4 nM, consistent with activation by thrombin of a protease-activated receptor (PAR). Actions of thrombin at PARs can be mimicked by thrombin receptor-activating peptides (TRAPs). TRAPs for PAR-1 reproduced the injury caused by thrombin in isolated livers, suggesting that one mechanism by which thrombin promotes LPS-induced liver injury is by activating PAR-1. Immunocytochemistry demonstrated the presence of PAR-1 on sinusoidal endothelial cells and Kupffer cells but not on parenchymal cells or neutrophils. Previous studies showed that thrombin interacts with neutrophils in the genesis of liver injury after LPS treatment. To explore this interaction further, the influence of thrombin on mediators that modulate neutrophil function were evaluated. Inhibition of thrombin in LPS-treated rats prevented liver injury but did not prevent up-regulation of cytokine-induced neutrophil chemoattractant-1, macrophage inflammatory protein-2, or intercellular adhesion molecule-1. Thrombin inhibition did, however, prevent neutrophil (PMN) degranulation in vivo as measured by plasma elastase levels. In addition, elastase concentration was increased in the perfusion medium of livers isolated from LPS-treated rats and perfused with TRAPs. These results suggest that activation of PAR-1 after LPS exposure promotes PMN activation and hepatic parenchymal cell injury.

Complement factor C5a mediates renal ischemia-reperfusion injury independent from neutrophils

The complement system has been shown to mediate renal ischemia-reperfusion (I/R) injury. However, the contribution of complement factor C5a to I/R injury, in particular in the kidney, remains to be established. In this study, we investigated the impact of blocking the C5aR pathway on the inflammatory response and on the renal function in a murine model of I/R injury. First, we analyzed C5aR expression in kidneys of healthy mice. Intriguingly, we found expression on mesangial, as well as on tubular epithelial, cells. After I/R injury, C5aR expression was up-regulated in tubular epithelial cells. In addition, mRNA levels of CXC chemokines and TNF-alpha increased significantly and kidneys were heavily infiltrated by neutrophils. Blocking the C5aR pathway by a specific C5a receptor antagonist (C5aRA) abrogated up-regulation of CXC chemokines but not of TNF-alpha and reduced neutrophil infiltration by >50%. Moreover, application of the C5aRA significantly reduced loss of renal function. This improvement of function was independent of the presence of neutrophils because neutrophil depletion by mAb NIMP-R14 did not affect the protective effect of C5aRA treatment. Furthermore, blocking of the C5aR pathway had no influence on renal apoptosis. These data provide evidence that C5a is crucially involved in the pathogenesis of renal I/R injury by modulation of neutrophil-dependent as well as neutrophil-independent pathways, which include the regulation of CXC chemokines but not TNF-alpha or apoptotic pathways.

Proinflammatory activities of S100: proteins S100A8, S100A9, and S100A8/A9 induce neutrophil chemotaxis and adhesion

S100A8 and S100A9 are small calcium-binding proteins that are highly expressed in neutrophil and monocyte cytosol and are found at high levels in the extracellular milieu during inflammatory conditions. Although reports have proposed a proinflammatory role for these proteins, their extracellular activity remains controversial. In this study, we report that S100A8, S100A9, and S100A8/A9 caused neutrophil chemotaxis at concentrations of 10(-12)-10(-9) M. S100A8, S100A9, and S100A8/A9 stimulated shedding of L-selectin, up-regulated and activated Mac-1, and induced neutrophil adhesion to fibrinogen in vitro. Neutralization with Ab showed that this adhesion was mediated by Mac-1. Neutrophil adhesion was also associated with an increase in intracellular calcium levels. However, neutrophil activation by S100A8, S100A9, and S100A8/A9 did not induce actin polymerization. Finally, injection of S100A8, S100A9, or S100A8/A9 into a murine air pouch model led to rapid, transient accumulation of neutrophils confirming their activities in vivo. These studies 1) show that S100A8, S100A9, and S100A8/A9 are potent stimulators of neutrophils and 2) strongly suggest that these proteins are involved in neutrophil migration to inflammatory sites.

GRO-alpha and CXCR2 in the human fetal brain and multiple sclerosis lesions

Chemokines, small proinflammatory cytokines, are involved in migration of inflammatory cells, but also have a role in normal central nervous system development. One chemokine, growth-related oncogene-alpha (GRO-alpha) and its receptor CXCR2, are involved in proliferation and migration of oligodendrocyte progenitors in rats. Here we studied the regional and cell type-specific expression of GRO-alpha and CXCR2 in the human telencephalon at midgestation, the time that oligodendrocytes are being generated in the human brain. Our results showed that both GRO-alpha and CXCR2 are predominately expressed by oligodendrocyte progenitors and activated microglial cells in the highly proliferative subventricular zone. This cellular and regional localization suggests that GRO-alpha/CXCR2 may play a role in human oligodendrocyte proliferation and subsequent migration. We also studied the expression of GRO-alpha and CXCR2 in brain sections of multiple sclerosis (MS) patients. Consistent with their role in the inflammatory process of MS, both GRO-alpha and CXCR2 were expressed in activated microglia localized on the border of MS lesions. However, neither GRO-alpha nor CXCR2 were present in early oligodendrocyte progenitors, a finding that may partially explain why remyelination is not more efficient in MS.

Stromal cell-derived factor 1 is secreted by meningeal cells and acts as chemotactic factor on neuronal stem cells of the cerebellar external granular layer

The cerebellar external granular layer (EGL) is an unusually long-lasting neural proliferative zone positioned immediately beneath the pial surface. Its position and stability critically depend on meningeal cells, as their selective destruction leads to its rapid dispersal, creating massive cortical ectopia. Similar ectopias have recently been described as a side effect of deficiency for stromal cell-derived factor 1 (SDF-1), a chemoattractant for haematopoietic precursor cell migration. Here we show that SDF-1 is present in meningeal cells in vivo and in vitro, where it is secreted in functionally relevant concentrations into the medium. Correspondingly, the SDF-1 receptor (termed CXCR4) can be demonstrated on stem cells of the external granular layer, but is absent on postmitotic cells commencing their final inward migration. We show that SDF-1 is concentrated by heparan sulphate proteoglycans highly expressed in the EGL in a laminar fashion, which thus might act to locally restrict SDF-1 action to the EGL in a kind of step gradient. In vitro, SDF-1 chemotactically attracts neuronal cells isolated from the external, but not from the internal granular layer, in a Boyden chamber assay in concentrations found in meningeal cell-conditioned medium. Selective removal of SDF-1 from conditioned media by immunoprecipitation abolishes their chemoattractive action, which can be reconstituted again by the addition of recombinant SDF-1. Meningeal cells are thus an important source for the expression of SDF-1 during brain development, which--comparable to its role in haematopoiesis--appears to be a key factor attracting precursor cells to their proliferative compartment.

The primary role in biologic activity of the neutrophil chemokines IL-8 and GRO-alpha in cultured nasal epithelial cells

Primary nasal epithelial cells were investigated for their ability to synthesize and deliver neutrophil chemotactic factors (chemokines) following tumor necrosis factor-alpha (TNF-alpha) induction. The chemokines interleukin8 (IL-8), growth-related oncogene-alpha (GRO-alpha), epithelial cell-derived neutrophil attractant-78 (ENA-78), and granulocyte chemotactic protein-2 (GCP-2) have been detected and characterized and shown to have different potencies in the chemotaxis of neutrophils. Cultures of primary nasal epithelial cells were treated with TNF-alpha in concentrations of 20 and 200 ng/ml for 2, 8, 24, and 72 h. The chemokine protein concentrations in the supernatants of the incubations were determined by the ELISA technique. Chemokine mRNA expression in epithelial cells was also measured using the reverse transcriptase-polymerase chain reaction (RT-PCR). The biologic activity of the chemokines was identified using a three-step high-performance liquid chromatography (HPLC) technique, a bioassay involving measurement of neutrophil chemotaxis in a single Boyden chamber. Both the IL-8 and GRO-alpha proteins and their respective mRNA appear to be induced by TNF-alpha in epithelial cells. The chemotactic responsiveness of both GRO-alpha and IL-8 appears to predominate after 24 h incubation with TNF-alpha. The chemokines GCP-2 and ENA-78 were only weakly induced by TNF-alpha. The neutrophil chemokines IL-8 and GRO-alpha were synthesized in nasal epithelial cell culture induced by TNF-alpha in biologically active concentrations of 0.8 ng/ml and 1.42 ng/ml, respectively. It appears that both the IL-8 and GRO-alpha chemokines may contribute to neutrophil tissue migration in sinusitis, whereas GCP-2 and ENA-78 are of secondary importance to the chemotaxis of neutrophils in this condition.

Interferon-gamma enhances the pulmonary CXC chemokine response to intratracheal lipopolysaccharide challenge

CXC chemokines are major chemoattractants for pulmonary polymorphonuclear leukocyte (PMNL) recruitment. To study the effects of interferon (IFN)-gamma on the pulmonary chemokine response to lipopolysaccharide (LPS) challenge, rats were treated with intratracheal IFN-gamma (1x10(5) U/rat) 24 h before an intratracheal LPS (100 microg/rat) challenge. Intratracheal LPS caused significant increases in both cytokine-induced neutrophil chemoattractant (CINC) and macrophage inflammatory protein-2 in bronchoalveolar lavage (BAL) fluid and pulmonary PMNL recruitment. IFN-gamma enhanced these responses. IFN-gamma also increased LPS-induced tumor necrosis factor (TNF)-alpha in BAL fluid. LPS-induced TNF-alpha and CINC mRNA expression in alveolar macrophages was increased by IFN-gamma. CD11b/c and CD18 expression on circulating PMNLs was not affected by IFN-gamma, nor was the chemotaxis of these cells. IFN-gamma increases the pulmonary CXC chemokine response, which may serve as one mechanism underlying enhanced PMNL delivery into the lung.