75 research outputs found

    Production of volatile fatty acids from slaughterhouse blood by mixed-culture fermentation

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    The volatile fatty acids (VFA) production potential from animal blood and the factors affecting this process were investigated in this study. In order to simulate an industrial process different operation modes, batch, fed batch and semi-continuous, were also evaluated. Due to high ammonia concentration in fermentation broth, VFA concentration up to 100 g L-1 was achieved without addition of buffer and methanogen inhibitor. In general, acetic, n-butyric and iso-valeric acids were the most predominant species, although different operational conditions affected the VFA concentration, profile, production rate and yield. The microbial community analysis was conducted on the reactors with the best performance, revealing that 70-90% of the microbial population was from the Clostridiales order with a strong presence from the Sporanaerobacter genus. These results demonstrated the feasibility of a VFA-platform bio-refinery using high-protein wastes as substrate via mixed-culture fermentation under non-sterilised conditions

    Age-related changes in the local milieu of inflamed tissues cause aberrant neutrophil trafficking and subsequent remote organ damage

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    Aging is associated with dysregulated immune functions. Here, we investigated the impact of age on neutrophil diapedesis. Using confocal intravital microscopy, we found that in inflamed aged tissues neutrophils exhibited a high frequency of reverse transendothelial migration (rTEM). This retrograde breaching of the endothelium by neutrophils was governed by enhanced production of the chemokine CXCL1 from mast cells that localized at endothelial cell (EC) junctions. Increased EC expression of the atypical chemokine receptor 1 (ACKR1) supported this pro-inflammatory milieu in aged venules. Accumulation of CXCL1 caused desensitization of the chemokine receptor CXCR2 on neutrophils and loss of neutrophil directional motility within EC junctions. Fluorescent tracking revealed that in aged mice, neutrophils undergoing rTEM re-entered the circulation and disseminated to the lungs where they caused vascular leakage. Thus, neutrophils stemming from a local inflammatory site contribute to remote organ damage, with implication to the dysregulated systemic inflammation associated with aging

    Age-related changes in the local milieu of inflamed tissues cause aberrant neutrophil trafficking and subsequent remote organ damage

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    Aging is associated with dysregulated immune functions. Here, we investigated the impact of age on neutrophil diapedesis. Using confocal intravital microscopy, we found that in aged mice, neutrophils adhered to vascular endothelium in inflamed tissues but exhibited a high frequency of reverse transendothelial migration (rTEM). This retrograde breaching of the endothelium by neutrophils was governed by enhanced production of the chemokine CXCL1 from mast cells that localized at endothelial cell (EC) junctions. Increased EC expression of the atypical chemokine receptor 1 (ACKR1) supported this pro-inflammatory milieu in aged venules. Accumulation of CXCL1 caused desensitization of the chemokine receptor CXCR2 on neutrophils and loss of neutrophil directional motility within EC junctions. Fluorescent tracking revealed that in aged mice, neutrophils undergoing rTEM re-entered the circulation and disseminated to the lungs where they caused vascular leakage. Thus, neutrophils stemming from a local inflammatory site contribute to remote organ damage, with implication to the dysregulated systemic inflammation associated with aging

    Tracking of dietary intakes in early childhood : the Melbourne InFANT program

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    Background/Objectives: The objectives of the present study were to describe food and nutrient intakes in children aged 9 and 18 months, and to assess tracking of intakes between these two ages.Subjects/Methods: Participants were 177 children of first-time mothers from the control arm of the Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program. Dietary intake was collected at 9 and 18 months using three 24&thinsp;h diet recalls. Tracking was assessed for food and nutrient intakes using logistic regression analysis and estimating partial correlation coefficients, respectively.Results: Although overall nutrient intakes estimated in this study did not indicate a particular risk of nutrient deficiency, our findings suggest that consumption of energy-dense, nutrient-poor foods occurred as early as 9 months of age, with some of these foods tracking highly over the weaning period. Intakes of healthier foods such as fruits, vegetables, dairy products, eggs, fish and water were also relatively stable over this transition from infancy to toddlerhood, along with moderate tracking for riboflavin, iodine, fibre, calcium and iron. Tracking was low but close to &rho;=0.3 for zinc, magnesium and potassium intakes.Conclusions: The tracking of energy-dense, nutrient-poor foods has important implications for public health, given the development of early eating behaviours is likely to be modifiable. At this stage of life, dietary intakes are largely influenced by the foods parents provide, parental feeding practices and modelling. This study supports the importance of promoting healthy dietary trajectories from infancy.<br /

    Jak3 Is Involved in Dendritic Cell Maturation and CCR7-Dependent Migration

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    BACKGROUND: CCR7-mediated signalling is important for dendritic cell maturation and homing to the lymph nodes. We have previously demonstrated that Jak3 participates in the signalling pathway of CCR7 in T lymphocytes. METHODOLOGY AND PRINCIPAL FINDINGS: Here, we used Jak3(-/-) mice to analyze the role of Jak3 in CCR7-mediated dendritic cells migration and function. First, we found no differences in the generation of DCs from Jak3(-/-) bone marrow progenitors, when compared to wild type cells. However, phenotypic analysis of the bone marrow derived DCs obtained from Jak3(-/-) mice showed reduced expression of co-stimulatory molecules compared to wild type (Jak3(+/+)). In addition, when we analyzed the migration of Jak3(-/-) and Jak3(+/+) mature DCs in response to CCL19 and CCL21 chemokines, we found that the absence of Jak3 results in impaired chemotactic responses both in vitro and in vivo. Moreover, lymphocyte proliferation and contact hypersensitivity experiments showed that DC-mediated T lymphocyte activation is reduced in the absence of Jak3. CONCLUSION/SIGNIFICANCE: Altogether, our data provide strong evidence that Jak3 is important for DC maturation, migration and function, through a CCR7-mediated signalling pathway

    Mutations in ASXL1 are associated with poor prognosis across the spectrum of malignant myeloid diseases

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    The ASXL1 gene is one of the most frequently mutated genes in malignant myeloid diseases. The ASXL1 protein belongs to protein complexes involved in the epigenetic regulation of gene expression. ASXL1 mutations are found in myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia (AML). They are generally associated with signs of aggressiveness and poor clinical outcome. Because of this, a systematic determination of ASXL1 mutational status in myeloid malignancies should help in prognosis assessment

    Expression of osterix Is Regulated by FGF and Wnt/β-Catenin Signalling during Osteoblast Differentiation

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    Osteoblast differentiation from mesenchymal cells is regulated by multiple signalling pathways. Here we have analysed the roles of Fibroblast Growth Factor (FGF) and canonical Wingless-type MMTV integration site (Wnt/β-Catenin) signalling pathways on zebrafish osteogenesis. We have used transgenic and chemical interference approaches to manipulate these pathways and have found that both pathways are required for osteoblast differentiation in vivo. Our analysis of bone markers suggests that these pathways act at the same stage of differentiation to initiate expression of the osteoblast master regulatory gene osterix (osx). We use two independent approaches that suggest that osx is a direct target of these pathways. Firstly, we manipulate signalling and show that osx gene expression responds with similar kinetics to that of known transcriptional targets of the FGF and Wnt pathways. Secondly, we have performed ChIP with transcription factors for both pathways and our data suggest that a genomic region in the first intron of osx mediates transcriptional activation. Based upon these data, we propose that FGF and Wnt/β-Catenin pathways act in part by directing transcription of osx to promote osteoblast differentiation at sites of bone formation

    Nck2 promotes human melanoma cell proliferation, migration and invasion in vitro and primary melanoma-derived tumor growth in vivo

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    <p>Abstract</p> <p>Background</p> <p>Nck1 and Nck2 adaptor proteins are involved in signaling pathways mediating proliferation, cytoskeleton organization and integrated stress response. Overexpression of Nck1 in fibroblasts has been shown to be oncogenic. Through the years this concept has been challenged and the consensus is now that overexpression of either Nck cooperates with strong oncogenes to transform cells. Therefore, variations in Nck expression levels in transformed cells could endorse cancer progression.</p> <p>Methods</p> <p>Expression of Nck1 and Nck2 proteins in various cancer cell lines at different stages of progression were analyzed by western blots. We created human primary melanoma cell lines overexpressing GFP-Nck2 and investigated their ability to proliferate along with metastatic characteristics such as migration and invasion. By western blot analysis, we compared levels of proteins phosphorylated on tyrosine as well as cadherins and integrins in human melanoma cells overexpressing or not Nck2. Finally, in mice we assessed tumor growth rate of human melanoma cells expressing increasing levels of Nck2.</p> <p>Results</p> <p>We found that expression of Nck2 is consistently increased in various metastatic cancer cell lines compared with primary counterparts. Particularly, we observed significant higher levels of Nck2 protein and mRNA, as opposed to no change in Nck1, in human metastatic melanoma cell lines compared with non-metastatic melanoma and normal melanocytes. We demonstrated the involvement of Nck2 in proliferation, migration and invasion in human melanoma cells. Moreover, we discovered that Nck2 overexpression in human primary melanoma cells correlates with higher levels of proteins phosphorylated on tyrosine residues, assembly of Nck2-dependent pY-proteins-containing molecular complexes and downregulation of cadherins and integrins. Importantly, we uncovered that injection of Nck2-overexpressing human primary melanoma cells into mice increases melanoma-derived tumor growth rate.</p> <p>Conclusions</p> <p>Collectively, our data indicate that Nck2 effectively influences human melanoma phenotype progression. At the molecular level, we propose that Nck2 in human primary melanoma promotes the formation of molecular complexes regulating proliferation and actin cytoskeleton dynamics by modulating kinases or phosphatases activities that results in increased levels of proteins phosphorylated on tyrosine residues. This study provides new insights regarding cancer progression that could impact on the therapeutic strategies targeting cancer.</p

    Endogenous VEGF Is Required for Visual Function: Evidence for a Survival Role on Müller Cells and Photoreceptors

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    Vascular endothelial growth factor (VEGF) is well known for its role in normal and pathologic neovascularization. However, a growing body of evidence indicates that VEGF also acts on non-vascular cells, both developmentally as well as in the adult. In light of the widespread use of systemic and intraocular anti-VEGF therapies for the treatment of angiogenesis associated with tumor growth and wet macular degeneration, systematic investigation of the role of VEGF in the adult retina is critical.Using immunohistochemistry and Lac-Z reporter mouse lines, we report that VEGF is produced by various cells in the adult mouse retina and that VEGFR2, the primary signaling receptor, is also widely expressed, with strong expression by Müller cells and photoreceptors. Systemic neutralization of VEGF was accomplished in mice by adenoviral expression of sFlt1. After 14 days of VEGF neutralization, there was no effect on the inner and outer retina vasculature, but a significant increase in apoptosis of cells in the inner and outer nuclear layers. By four weeks, the increase in neural cell death was associated with reduced thickness of the inner and outer nuclear layers and a decline in retinal function as measured by electroretinograms. siRNA-based suppression of VEGF expression in a Müller cell line in vitro supports the existence of an autocrine role for VEGF in Müller cell survival. Similarly, the addition of exogenous VEGF to freshly isolated photoreceptor cells and outer-nuclear-layer explants demonstrated VEGF to be highly neuroprotective.These results indicate an important role for endogenous VEGF in the maintenance and function of adult retina neuronal cells and indicate that anti-VEGF therapies should be administered with caution
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