High S100A2 expression in keratinocytes in patients with drug eruption.

Telaprevir used as a protease inhibitor against hepatitis C virus is frequently associated with cutaneous adverse reactions. To explore a histological biomarker of cutaneous adverse events induced by telaprevir, we systematically searched for genes that were dysregulated by telaprevir in normal human epidermal keratinocytes (NHEKs). Microarray analysis and real-time polymerase chain reaction (PCR) revealed the significant increase in the expression of S100 calcium-binding protein A2 (S100A2) gene following treatment of NHEKs with telaprevir. Immunohistochemical analysis demonstrated that the expression of S100A2 was dominant in the spinous layer of the epidermis in patients with telaprevir-mediated severe-type drug eruptions and limited to the basal layer of the epidermis in healthy subjects. Furthermore, S100A2 expression increased after treatment with trichloroethylene and other medications, and the degree of S100A2 expression correlated with the severity of cutaneous adverse events. S100A2 expression also significantly increased in the skin of patients with atopic dermatitis and psoriasis. Taken together, S100A2 is highly expressed in the epidermis under inflammatory conditions and drug eruptions and may serve as a marker for keratinocyte damage in response to any inflammatory or toxic condition.

Development of 3D Lymph Node Mimetic for Studying Prostate Cancer Metastasis.

Lymph node (LN) metastasis causes poor prognosis for patients with prostate cancer (PCa). Although LN-cells and cellular responses play a pivotal role in cancer metastasis, the interplay between LN-cells and PCa cells is undetermined due to the small size and widespread distribution of LNs. To identify factors responsible for LN metastasis, a 3D cell culture biosystem is fabricated to simulate LN responses during metastasis. First, it is determined that LN explants previously exposed to high metastatic PCa release substantially more chemotactic factors to promote metastatic PCa migration than those exposed to low-metastatic PCa. Furthermore, T-lymphocytes are found to produce chemotactic factors in LNs, among which, CXCL12, CCL21, and IL-10 are identified to have the most chemotactic effect. To mimic the LN microenvironment, Cytodex beads are seeded with T cells to produce a LN-mimetic biosystem in both static and flow conditions. As expected, the flow condition permits prolonged cellular responses. Interestingly, when PCa cells with varying metastatic potentials are introduced into the system, it produces PCa-specific chemokines accordingly. These results support that the LN mimetic helps in analyzing the processes underlying metastasized LNs and for testing various treatments to reduce cancer LN metastasis.

Metabolically conditioned media derived from bone marrow stromal cells or human skin fibroblasts act as effective chemoattractants for mesenchymal stem cells.

BACKGROUND: The main goal of bone tissue engineering has been the generation of healthy bone in order to replace affected tissue. Therefore, optimized biomaterials are needed which allow the survival and growth of mesenchymal stem cells. Until now the key challenge in the clinical application of cell-based tissue engineering bone implants was poor diffusion of oxygen into the tissue, making functional blood vessel networks a necessity. With their ability to evolve into different cell types, to expand extensively in vitro, and to release paracrine soluble factors, bone marrow stromal cells (BMSC) are highly attractive for tissue engineering. During the last years hypoxia became a proven method to control proliferation, differentiation, and pluripotency of BMSC. Here we applied different methods to characterize metabolically conditioned media (MCM) in comparison to hypoxia conditioned media (HCM) and evaluated their ability to attract BMSC in 2-D migration assays. METHODS: BMSC and fibroblasts of human origin were isolated and cultivated to obtain HCM and MCM. Both media were characterized by angiogenesis arrays, cytokine arrays, and ELISA for selected factors. 2-D migration tests were performed with Corning Transwell®-96 permeable support chambers with porous polyester membranes with a pore size of 8.0 µm. RESULTS: Characterization of HCM and MCM revealed that the concentration of angiogenic factors was higher in MCM than in HCM. However, the chemoattractive capacity of MCM for BMSC was equivalent to that of HCM. HCM and MCM produced by human skin fibroblasts attracted human BMSC as efficiently as HCM and MCM produced by human BMSC. CONCLUSIONS: HCM and MCM have a high chemoattractive capacity for BMSC. Both conditioned media harbor high concentrations of angiogenic factors which are important for angiogenesis and cell migration. Both chemoattracting conditioned media can also be derived from skin fibroblasts which can easily be obtained from patients in individualized therapy approaches.

Disrupting ceramide-CD300f interaction prevents septic peritonitis by stimulating neutrophil recruitment.

Sepsis is a serious clinical problem. Negative regulation of innate immunity is associated with sepsis progression, but the underlying mechanisms remains unclear. Here we show that the receptor CD300f promotes disease progression in sepsis. CD300f -/- mice were protected from death after cecal ligation and puncture (CLP), a murine model of septic peritonitis. CD300f was highly expressed in mast cells and recruited neutrophils in the peritoneal cavity. Analysis of mice (e.g., mast cell-deficient mice) receiving transplants of wild-type or CD300f -/- mast cells or neutrophils indicated that CD300f deficiency did not influence intrinsic migratory abilities of neutrophils, but enhanced neutrophil chemoattractant production (from mast cells and neutrophils) in the peritoneal cavity of CLP-operated mice, leading to robust accumulation of neutrophils which efficiently eliminated Escherichia coli. Ceramide-CD300f interaction suppressed the release of neutrophil chemoattractants from Escherichia coli-stimulated mast cells and neutrophils. Administration of the reagents that disrupted the ceramide-CD300f interaction prevented CLP-induced sepsis by stimulating neutrophil recruitment, whereas that of ceramide-containing vesicles aggravated sepsis. Extracellular concentrations of ceramides increased in the peritoneal cavity after CLP, suggesting a possible role of extracellular ceramides, CD300f ligands, in the negative-feedback suppression of innate immune responses. Thus, CD300f is an attractive target for the treatment of sepsis.

Individual female differences in chemoattractant production change the scale of sea urchin gamete interactions.

Sperm selection by females is an important process influencing fertilization and, particularly in broadcast-spawning organisms, often occurs before sperm reach the egg. Waterborne sperm chemoattractants are one mechanism by which eggs selectively influence conspecific sperm behavior, but it remains an open question whether the eggs from different females produce different amounts of sperm chemoattractant, and how that might influence sperm behavior. Here, we quantify the differences in attractant production between females of the sea urchin species Lytechinus pictus and use computational models and microfluidic sperm chemotaxis assays to determine how differences in chemoattractant production between females affects their ability to attract sperm. Our study demonstrates that there is significant individual female variation in egg chemoattractant production, and that this variation changes the scope and strength of sperm attraction. These results provide evidence for the importance of individual female variability in differential sperm attraction and fertilization success.

Caterpillar-induced plant volatiles attract conspecific adults in nature.

Plants release volatiles in response to caterpillar feeding that attract natural enemies of the herbivores, a tri-trophic interaction which has been considered an indirect plant defence against herbivores. The caterpillar-induced plant volatiles have been reported to repel or attract conspecific adult herbivores. To date however, no volatile signals that either repel or attract conspecific adults under field conditions have been chemically identified. Apple seedlings uniquely released seven compounds including acetic acid, acetic anhydride, benzyl alcohol, benzyl nitrile, indole, 2-phenylethanol, and (E)-nerolidol only when infested by larvae of the light brown apple moth, Epiphyas postvittana. In field tests in New Zealand, a blend of two of these, benzyl nitrile and acetic acid, attracted a large number of conspecific male and female adult moths. In North America, male and female adults of the tortricid, oblique-banded leafroller, Choristoneura rosaceana, were most attracted to a blend of 2-phenylethanol and acetic acid. Both sexes of the eye-spotted bud moth, Spilonota ocellana, were highly attracted to a blend of benzyl nitrile and acetic acid. This study provides the first identification of caterpillar-induced plant volatiles that attract conspecific adult herbivores under natural conditions, challenging the expectation of herbivore avoidance of these induced volatiles.

Transcriptome analysis of phycocyanin inhibitory effects on SKOV-3 cell proliferation.

Phycocyanin (PC) from Spirulina platensis has inhibitory effects on tumor cell growth. In this research, the transcriptome study was designed to investigate the underlying molecular mechanisms of PC inhibition on human ovarian cancer cell SKOV-3 proliferation. The PC IC50 was 216.6µM and 163.8µM for 24h and 48h exposure, respectively, as determined by CCK-8 assay. The morphological changes of SKOV-3 cells after PC exposure were recorded using HE staining. Cells arrested in G2/M stages as determined by flow cytometry. The transcriptome analysis showed that 2031 genes (with > three-fold differences) were differentially expressed between the untreated and the PC-treated cells, including 1065 up-regulated and 966 down-regulated genes. Gene ontology and KEGG pathway analysis identified 18 classical pathways that were remarkably enriched, such as neurotrophin signaling pathway, VEGF signaling pathway and P53 signaling pathway. qPCR results further showed that PTPN12, S100A2, RPL26, and LAMA3 increased while HNRNPA1P10 decreased in PC-treated cells. Molecules and genes in those pathways may be potential targets to develop treatments for ovarian cancer.

Lymphangiogenic and Chemotactic Factors in Conjunctival Melanoma.

PURPOSE: The aim of this study was to evaluate expression patterns of known lymphangiogenic growth factors and chemokines in conjunctival melanoma, and to describe patterns of lymphatic vessel growth in these tumors. METHODS: This was a retrospective chart review comprising 5 participants (6 tumor specimens) and the main outcome measures were expression of growth factors, chemokines, and their receptors known to be important in tumor lymphangiogenesis as well as patterns of lymphatic vessel growth on immunohistochemical sections. RESULTS: Tumor cells in all specimens expressed lymphangiogenic growth factors VEGFC, VEGFD, and their receptor VEGFR3. Chemotactic factors CXCL12 and CCL21 and their receptors, CXCR4 and CCL21, were also expressed in tumor cells and lymphatic endothelial cells. Staining was most intense for these proteins at the invasive tumor edge, suggesting increased lymphangiogenic activity at this location. In addition, lymphatic vessels clustered near the invasive edge of the tumors. CONCLUSIONS: VEGFC, VEGFD, and VEGR3 are diffusely expressed by conjunctival melanoma cells, most intensely at the invasive tumor edge. CXCL12, CXCR4, CCL21, and CCR7 were also most intensely expressed at the invasive edge, where the highest density of lymphatic vessels was also observed. These expression patterns suggest that these mediators of tumor-associated lymphangiogenesis warrant further investigation as potential therapeutic targets in conjunctival melanoma.

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-ß-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.

iTRAQ-based quantitative proteomic analysis on S100 calcium binding protein A2 in metastasis of laryngeal cancer.

Laryngeal cancer is the most frequent neoplasm in the head and neck region, with the vast majority of tumors originating from squamous cells. The survival rate of patients with laryngeal cancer has not improved substantially over the past 25 years. To acquire further knowledge regarding the molecules responsible for laryngeal cancer oncogenesis and, in turn, to improve target therapy iTRAQ and mass spectrometry analysis were utilized to detect differences in protein expression from 15 paired laryngeal cancer and adjacent non-cancerous tissue samples. Using mass spectrometry analysis, the expression levels of 100 proteins in laryngeal cancer samples were distinct from the non-tumor, non-cancerous samples. Further validation of the differentially expressed proteins S100A2, KRT16, FGB and HSPB1 were carried out using quantitative real-time RT-PCR, immunoblot and immunohistochemistry. Functional analysis of one of the highly expressed proteins, S100 calcium binding protein A2 (S100A2), was performed using RNA interference. As a consequence, attenuated S100A2 expression enhanced the ability of HEp-2 cell lines to migrate and invade in vitro. Our investigation complements the current understanding of laryngeal cancer progression. Furthermore, this study supports the concept that enhanced expression of S100A2 may be a promising strategy in developing novel cancer therapeutic drugs.

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-1ß. 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.

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-1ß, 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.

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.

Chemerin is highly expressed in hepatocytes and is induced in non-alcoholic steatohepatitis liver.

Chemerin is a recently described adipokine whose adipose tissue and serum levels are increased in obesity. Chemerin is expressed in the liver, and here, expression of chemerin has been studied in liver cells and in non-alcoholic fatty liver disease (NAFLD) which is more often found in obesity. Chemerin is shown to be highly expressed in primary human hepatocytes (PHH) whereas hepatic stellate cells (HSC) produce only low levels of this protein. In mice fed a high fat diet hepatic chemerin mRNA but not protein is increased. Chemerin protein is comparably expressed in the liver of control animals and ob/ob mice. Rodents fed a Paigen diet or methionine-choline deficient diet (MCD) develop non-alcoholic steatohepatitis (NASH), and liver chemerin protein tends to be higher in the first and is significantly increased in the latter. Of note, MCD fed mice have similar serum chemerin levels as the respective control animals despite lower body weight. In human fatty liver and NASH liver chemerin mRNA also tends to be induced. Cytokines like TNF and adipokines with an established role in NASH do not considerably affect PHH chemerin protein. The antidiabetic drug metformin reduces cellular and soluble chemerin in PHH as has already been described in adipose tissue. In conclusion current data show that primary human hepatocytes are a major source of hepatic chemerin and increased liver chemerin in NASH may even contribute to systemic levels.

Ceramide-1-phosphate regulates migration of multipotent stromal cells and endothelial progenitor cells--implications for tissue regeneration.

Ceramide-1-phosphate (C1P) is a bioactive lipid that, in contrast to ceramide, is an antiapoptotic molecule released from cells that are damaged and "leaky." As reported recently, C1P promotes migration of hematopoietic cells. In this article, we tested the hypothesis that C1P released upon tissue damage may play an underappreciated role in chemoattraction of various types of stem cells and endothelial cells involved in tissue/organ regeneration. We show for the first time that C1P is upregulated in damaged tissues and chemoattracts bone marrow (BM)-derived multipotent stromal cells, endothelial progenitor cells, and very small embryonic-like stem cells. Furthermore, compared to other bioactive lipids, C1P more potently chemoattracted human umbilical vein endothelial cells and stimulated tube formation by these cells. C1P also promoted in vivo vascularization of Matrigel implants and stimulated secretion of stromal cell-derived factor-1 from BM-derived fibroblasts. Thus, our data demonstrate, for the first time, that C1P is a potent bioactive lipid released from damaged cells that potentially plays an important and novel role in recruitment of stem/progenitor cells to damaged organs and may promote their vascularization.

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.

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.

Processing of HEBP1 by cathepsin D gives rise to F2L, the agonist of formyl peptide receptor 3.

The peptide F2L was previously characterized as a high-affinity natural agonist for the human formyl peptide receptor (FPR) 3. F2L is an acetylated 21-aa peptide corresponding with the N terminus of the intracellular heme-binding protein 1 (HEBP1). In the current work, we have investigated which proteases were able to generate the F2L peptide from its precursor HEBP1. Structure-function analysis of F2L identified three amino acids, G(3), N(7), and S(8), as the most important for interaction of the peptide with FPR3. We expressed a C-terminally His-tagged form of human HEBP1 in yeast and purified it to homogeneity. The purified protein was used as substrate to identify proteases generating bioactive peptides for FPR3-expressing cells. A conditioned medium from human monocyte-derived macrophages was able to generate bioactivity from HEBP1, and this activity was inhibited by pepstatin A. Cathepsin D was characterized as the protease responsible for HEBP1 processing, and the bioactive product was identified as F2L. We have therefore determined how F2L, the specific agonist of FPR3, is generated from the intracellular protein HEBP1, although it is unknown in which compartment the processing by cathepsin D occurs in vivo.

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.