114 research outputs found

    Influence of energy balance on the antimicrobial peptides S100A8 and S100A9 in the endometrium of the postpartum dairy cow

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    Uterine inflammation occurs after calving in association with extensive endometrial remodelling and bacterial contamination. If the inflammation persists, it leads to reduced fertility. Chronic endometritis is highly prevalent in high-yielding cows that experience negative energy balance (NEB) in early lactation. This study investigated the effect of NEB on the antimicrobial peptides S100A8 and S100A9 in involuting uteri collected 2 weeks post partum. Holstein-Friesian cows (six per treatment) were randomly allocated to two interventions designed to produce mild or severe NEB (MNEB and SNEB) status. Endometrial samples were examined histologically, and the presence of neutrophils, macrophages, lymphocytes and natural killer cells was confirmed using haematoxylin and eosin and immunostaining. SNEB cows had greater signs of uterine inflammation. Samples of previously gravid uterine horn were used to localise S100A8 and S100A9 by immunohistochemistry. Both S100 proteins were present in bovine endometrium with strong staining in epithelial and stromal cells and in infiltrated leucocytes. Immunostaining was significantly higher in SNEB cows along with increased numbers of segmented neutrophils. These results suggest that the metabolic changes of a post-partum cow suffering from NEB delay uterine involution and promote a chronic state of inflammation. We show that upregulation of S100A8 and S100A9 is clearly a key component of the early endometrial response to uterine infection. Further studies are warranted to link the extent of this response after calving to the likelihood of cows developing endometritis and to their subsequent fertility

    Early detection of breast cancer based on gene-expression patterns in peripheral blood cells

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    INTRODUCTION: Existing methods to detect breast cancer in asymptomatic patients have limitations, and there is a need to develop more accurate and convenient methods. In this study, we investigated whether early detection of breast cancer is possible by analyzing gene-expression patterns in peripheral blood cells. METHODS: Using macroarrays and nearest-shrunken-centroid method, we analyzed the expression pattern of 1,368 genes in peripheral blood cells of 24 women with breast cancer and 32 women with no signs of this disease. The results were validated using a standard leave-one-out cross-validation approach. RESULTS: We identified a set of 37 genes that correctly predicted the diagnostic class in at least 82% of the samples. The majority of these genes had a decreased expression in samples from breast cancer patients, and predominantly encoded proteins implicated in ribosome production and translation control. In contrast, the expression of some defense-related genes was increased in samples from breast cancer patients. CONCLUSION: The results show that a blood-based gene-expression test can be developed to detect breast cancer early in asymptomatic patients. Additional studies with a large sample size, from women both with and without the disease, are warranted to confirm or refute this finding

    S100A8/A9 Is Not Involved in Host Defense against Murine Urinary Tract Infection

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    Background: Inflammation is commonly followed by the release of endogenous proteins called danger associated molecular patterns (DAMPs) that are able to warn the host for eminent danger. S100A8/A9 subunits are DAMPs that belong to the S100 family of calcium binding proteins. S100A8/A9 complexes induce an inflammatory response and their expression correlates with disease severity in several inflammatory disorders. S100A8/A9 promote endotoxin-and Escherichia (E.) coli-induced sepsis showing its contribution in systemic infection. The role of S100A8/A9 during a local infection of the urinary tract system caused by E. coli remains unknown. Methodology/Principal Findings: We investigated the contribution of S100A8/A9 in acute urinary tract infection (UTI) by instilling 2 different doses of uropathogenic E. coli transurethrally in wild type (WT) and S100A9 knockout (KO) mice. Subsequently, we determined bacterial outgrowth, neutrophilic infiltrate and inflammatory mediators in bladder and kidney 24 and 48 hours later. UTI resulted in a substantial increase of S100A8/A9 protein in bladder and kidney tissue of WT mice. S100A9 KO mice displayed similar bacterial load in bladder or kidney homogenate compared to WT mice using 2 different doses at 2 different time points. S100A9 deficiency had little effect on the inflammatory responses to E. Coli-induced UTI infection, as assessed by myeloperoxidase activity in bladder and kidneys, histopathologic analysis, and renal and bladder cytokine concentrations. Conclusions: We show that despite high S100A8/A9 expression in bladder and kidney tissue upon UTI, S100A8/A9 does not contribute to an effective host response against E. Coli in the urinary tract syste

    Transcriptomic analysis of the temporal host response to skin infestation with the ectoparasitic mite Psoroptes ovis

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    <p>Abstract</p> <p>Background</p> <p>Infestation of ovine skin with the ectoparasitic mite <it>Psoroptes ovis </it>results in a rapid cutaneous immune response, leading to the crusted skin lesions characteristic of sheep scab. Little is known regarding the mechanisms by which such a profound inflammatory response is instigated and to identify novel vaccine and drug targets a better understanding of the host-parasite relationship is essential. The main objective of this study was to perform a combined network and pathway analysis of the <it>in vivo </it>skin response to infestation with <it>P. ovis </it>to gain a clearer understanding of the mechanisms and signalling pathways involved.</p> <p>Results</p> <p>Infestation with <it>P. </it>ovis resulted in differential expression of 1,552 genes over a 24 hour time course. Clustering by peak gene expression enabled classification of genes into temporally related groupings. Network and pathway analysis of clusters identified key signalling pathways involved in the host response to infestation. The analysis implicated a number of genes with roles in allergy and inflammation, including pro-inflammatory cytokines (<it>IL1A, IL1B, IL6, IL8 </it>and <it>TNF</it>) and factors involved in immune cell activation and recruitment (<it>SELE, SELL, SELP, ICAM1, CSF2, CSF3, CCL2 </it>and <it>CXCL2</it>). The analysis also highlighted the influence of the transcription factors NF-kB and AP-1 in the early pro-inflammatory response, and demonstrated a bias towards a Th2 type immune response.</p> <p>Conclusions</p> <p>This study has provided novel insights into the signalling mechanisms leading to the development of a pro-inflammatory response in sheep scab, whilst providing crucial information regarding the nature of mite factors that may trigger this response. It has enabled the elucidation of the temporal patterns by which the immune system is regulated following exposure to <it>P. ovis</it>, providing novel insights into the mechanisms underlying lesion development. This study has improved our existing knowledge of the host response to <it>P. ovis</it>, including the identification of key parallels between sheep scab and other inflammatory skin disorders and the identification of potential targets for disease control.</p

    Keratin and S100 calcium-binding proteins are major constituents of the bovine teat canal lining

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    The bovine teat canal provides the first-line of defence against pathogenic bacteria infecting the mammary gland, yet the protein composition and host-defence functionality of the teat canal lining (TCL) are not well characterised. In this study, TCL collected from six healthy lactating dairy cows was subjected to two-dimensional electrophoresis (2-DE) and mass spectrometry. The abundance and location of selected identified proteins were determined by western blotting and fluorescence immunohistochemistry. The variability of abundance among individual cows was also investigated. Two dominant clusters of proteins were detected in the TCL, comprising members of the keratin and S100 families of proteins. The S100 proteins were localised to the teat canal keratinocytes and were particularly predominant in the cornified outermost layer of the teat canal epithelium. Significant between-animal variation in the abundance of the S100 proteins in the TCL was demonstrated. Four of the six identified S100 proteins have been reported to have antimicrobial activity, suggesting that the TCL has additional functionality beyond being a physical barrier to invading microorganisms. These findings provide new insights into understanding host-defence of the teat canal and resistance of cows to mastitis

    Subversion of antimicrobial calprotectin (S100A8/S100A9 complex) in the cytoplasm of TR146 epithelial cells after invasion by Listeria monocytogenes

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Expressed by squamous mucosal keratinocytes, calprotectin is a complex of two EF-hand calcium-binding proteins of the S100 subfamily (S100A8 and S100A9) with significant antimicrobial activity. Calprotectin-expressing cells resist invasion by Porphyromonas gingivalis, Listeria monocytogenes, and Salmonella enterica serovar Typhimurium ( S. typhimurium). To understand the interactions between calprotectin and invasive bacteria, we studied the distribution of calprotectin in the cytoplasm of TR146 epithelial cells. In response to L. monocytogenes, calprotectin mobilized from a diffuse cytoplasmic distribution to a filamentous pattern and colocalized with the microtubule network. Listeria more frequently invaded cells with mobilized calprotectin. Calprotectin mobilization was listeriolysin O-dependent and required calcium ( extracellular and intracellular) and an intact microtubule network. In the presence of preformed microtubules in vitro, the anti-Listeria activity of calprotectin was abrogated. To facilitate intraepithelial survival, therefore, Listeria mobilizes calprotectin to colocalize with cytoplasmic microtubules, subverting anti-Listeria activity and autonomous cellular immunity.214353NIH [RO1DE11831, P30DE09737, RO1GM62112]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The Royal Thai governmentFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)NIH [RO1DE11831, P30DE09737, RO1GM62112]FAPESP [99/10079-4
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