554 research outputs found

    Distinct roles of the RasGAP family proteins in C. elegans associative learning and memory

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    The Ras GTPase activating proteins (RasGAPs) are regulators of the conserved Ras/MAPK pathway. Various roles of some of the RasGAPs in learning and memory have been reported in different model systems, yet, there is no comprehensive study to characterize all gap genes in any organism. Here, using reverse genetics and neurobehavioural tests, we studied the role of all known genes of the rasgap family in C. elegans in associative learning and memory. We demonstrated that their proteins are implicated in different parts of the learning and memory processes. We show that gap-1 contribute redundantly with gap-3 to the chemosensation of volatile compounds, gap-1 plays a major role in associative learning, while gap-2 and gap-3 are predominantly required for short- and long-term associative memory. Our results also suggest that the C. elegans Ras orthologue let-60 is involved in multiple processes during learning and memory. Thus, we show that the different classes of RasGAP proteins are all involved in cognitive function and their complex interplay ensures the proper formation and storage of novel information in C. elegans

    Impact of Aspergillus fumigatus in allergic airway diseases

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    For decades, fungi have been recognized as associated with asthma and other reactive airway diseases. In contrast to type I-mediated allergies caused by pollen, fungi cause a large number of allergic diseases such as allergic bronchopulmonary mycoses, rhinitis, allergic sinusitis and hypersensitivity pneumonitis. Amongst the fungi, Aspergillus fumigatus is the most prevalent cause of severe pulmonary allergic disease, including allergic bronchopulmonary aspergillosis (ABPA), known to be associated with chronic lung injury and deterioration in pulmonary function in people with chronic asthma and cystic fibrosis (CF). The goal of this review is to discuss new understandings of host-pathogen interactions in the genesis of allergic airway diseases caused by A. fumigatus. Host and pathogen related factors that participate in triggering the inflammatory cycle leading to pulmonary exacerbations in ABPA are discussed

    Mucosal sensitization to German cockroach involves protease-activated receptor-2

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    <p>Abstract</p> <p>Background</p> <p>Allergic asthma is on the rise in developed countries. A common characteristic of allergens is that they contain intrinsic protease activity, and many have been shown to activate protease-activated receptor (PAR)-2 <it>in vitro</it>. The role for PAR-2 in mediating allergic airway inflammation has not been assessed using a real world allergen.</p> <p>Methods</p> <p>Mice (wild type or PAR-2-deficient) were sensitized to German cockroach (GC) feces (frass) or protease-depleted GC frass by either mucosal exposure or intraperitoneal injection and measurements of airway inflammation (IL-5, IL-13, IL-17A, and IFNγ levels in the lung, serum IgE levels, cellular infiltration, mucin production) and airway hyperresponsiveness were performed.</p> <p>Results</p> <p>Following systemic sensitization, GC frass increased airway hyperresponsiveness, Th2 cytokine release, serum IgE levels, cellular infiltration and mucin production in wild type mice. Interestingly, PAR-2-deficient mice had similar responses as wild type mice. Since these data were in direct contrast to our finding that mucosal sensitization with GC frass proteases regulated airway hyperresponsiveness and mucin production in BALB/c mice (Page et. al. 2007 Resp Res 8:91), we backcrossed the PAR-2-deficient mice into the BALB/c strain. Sensitization to GC frass could now occur via the more physiologically relevant method of intratracheal inhalation. PAR-2-deficient mice had significantly reduced airway hyperresponsiveness, Th2 and Th17 cytokine release, serum IgE levels, and cellular infiltration compared to wild type mice when sensitization to GC frass occurred through the mucosa. To confirm the importance of mucosal exposure, mice were systemically sensitized to GC frass or protease-depleted GC frass via intraperitoneal injection. We found that removal of proteases from GC frass had no effect on airway inflammation when administered systemically.</p> <p>Conclusions</p> <p>We showed for the first time that allergen-derived proteases in GC frass elicit allergic airway inflammation via PAR-2, but only when allergen was administered through the mucosa. Importantly, our data suggest the importance of resident airway cells in the initiation of allergic airway disease, and could make allergen-derived proteases attractive therapeutic targets.</p

    Therapeutic efficacy in a hemophilia B model using a biosynthetic mRNA liver depot system

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    DNA-based gene therapy has considerable therapeutic potential, but the challenges associated with delivery continue to limit progress. Messenger RNA (mRNA) has the potential to provide for transient production of therapeutic proteins, without the need for nuclear delivery and without the risk of insertional mutagenesis. Here we describe the sustained delivery of therapeutic proteins in vivo in both rodents and non-human primates via nanoparticle-formulated mRNA. Nanoparticles formulated with lipids and lipid-like materials were developed for delivery of two separate mRNA transcripts encoding either human erythropoietin (hEPO) or factor IX (hFIX) protein. Dose-dependent protein production was observed for each mRNA construct. Upon delivery of hEPO mRNA in mice, serum EPO protein levels reached several orders of magnitude (>125 000-fold) over normal physiological values. Further, an increase in hematocrit (Hct) was established, demonstrating that the exogenous mRNA-derived protein maintained normal activity. The capacity of producing EPO in non-human primates via delivery of formulated mRNA was also demonstrated as elevated EPO protein levels were observed over a 72-h time course. Exemplifying the possible broad utility of mRNA drugs, therapeutically relevant amounts of human FIX (hFIX) protein were achieved upon a single intravenous dose of hFIX mRNA-loaded lipid nanoparticles in mice. In addition, therapeutic value was established within a hemophilia B (FIX knockout (KO)) mouse model by demonstrating a marked reduction in Hct loss following injury (incision) to FIX KO mice

    Association of IL-4RA single nucleotide polymorphisms, HLA-DR and HLA-DQ in children with Alternaria-sensitive moderate-severe asthma

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    <p>Abstract</p> <p>Background</p> <p>Asthma afflicts 6% to 8% of the United States population, and severe asthma represents approximately 10% of asthmatic patients. Several epidemiologic studies in the United States and Europe have linked <it>Alternaria </it>sensitivity to both persistence and severity of asthma. In order to begin to understand genetic risk factors underlying <it>Alternaria </it>sensitivity and asthma, in these studies we examined T cell responses to <it>Alternaria </it>antigens, HLA Class II restriction and HLA-DQ protection in children with severe asthma.</p> <p>Methods</p> <p>Sixty children with <it>Alternaria</it>-sensitive moderate-severe asthma were compared to 49 children with <it>Alternaria</it>-sensitive mild asthma. We examined HLA-DR and HLA-DQ frequencies in <it>Alternaria</it>-sensitive asthmatic by HLA typing. To determine ratios of Th1/Th2 <it>Alternaria</it>-specific T-cells, cultures were stimulated in media alone, <it>Alternaria alternata </it>extract and Alt a1. Sensitivity to IL-4 stimulation was measured by up-regulation of CD23 on B cells.</p> <p>Results</p> <p>Children with <it>Alternaria</it>-sensitive moderate-severe asthma trended to have increased sensitivities to <it>Cladosporium </it>(46% versus 35%), to <it>Aspergillus </it>(43% versus 28%), and significantly increased sensitivities to trees (78% versus 57%) and to weeds (68% versus 48%). The IL-4RA ile75val polymorphism was significantly increased in <it>Alternaria</it>-sensitive moderate-severe asthmatics, 83% (0.627 allele frequency) compared to <it>Alternaria</it>-sensitive mild asthmatics, 57% (0.388 allele frequency). This was associated with increased sensitivity to IL-4 stimulation measured by significantly increased IL-4 stimulated CD23 expression on CD19+ and CD86+CD19+ B cells of <it>Alternaria</it>-sensitive moderate-severe asthmatics. IL-5 and IL-13 synthesis was significantly increased in <it>Alternaria</it>-sensitive moderate-severe asthmatics compared to mild asthmatics to <it>Alternaria </it>extract and Alt a1 stimulation. The frequency of HLA-DQB1*03 allele was significantly decreased in <it>Alternaria</it>-sensitive moderate-severe asthmatics compared to mild asthmatics, 39% versus 63%, with significantly decreased allele frequency, 0.220 versus 0.398.</p> <p>Summary</p> <p>In children with <it>Alternaria</it>-sensitive moderate severe asthma, there was an increased Th2 response to <it>Alternaria </it>stimulation and increased sensitivity to IL-4 stimulation. This skewing towards a Th2 response was associated with an increased frequency of the IL-4RA ile75val polymorphism. In evaluating the HLA association, there was a decreased frequency of HLA-DQB1*03 in <it>Alternaria</it>-sensitive moderate severe asthmatic children consistent with previous studies suggest that HLA-DQB1*03 may be protective against the development of mold-sensitive severe asthma.</p

    Immune response CC chemokines CCL2 and CCL5 are associated with pulmonary sarcoidosis

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    Abstract Background Pulmonary sarcoidosis involves an intense leukocyte infiltration of the lung with the formation of non-necrotizing granulomas. CC chemokines (chemokine (C-C motif) ligand 2 (CCL2)-CCL5) are chemoattractants of mononuclear cells and act through seven transmembrane G-coupled receptors. Previous studies have demonstrated conflicting results with regard to the associations of these chemokines with sarcoidosis. In an effort to clarify previous discrepancies, we performed the largest observational study to date of CC chemokines in bronchoalveolar lavage fluid (BALF) from patients with pulmonary sarcoidosis. Results BALF chemokine levels from 72 patients affected by pulmonary sarcoidosis were analyzed by enzyme-linked immunosorbent assay (ELISA) and compared to 8 healthy volunteers. BALF CCL3 and CCL4 levels from pulmonary sarcoidosis patients were not increased compared to controls. However, CCL2 and CCL5 levels were elevated, and subgroup analysis showed higher levels of both chemokines in all stages of pulmonary sarcoidosis. CCL2, CCL5, CC chemokine receptor type 1 (CCR1), CCR2 and CCR3 were expressed from mononuclear cells forming the lung granulomas, while CCR5 was only found on mast cells. Conclusions These data suggest that CCL2 and CCL5 are important mediators in recruiting CCR1, CCR2, and CCR3 expressing mononuclear cells as well as CCR5-expressing mast cells during all stages of pulmonary sarcoidosis

    Candida soluble cell wall β-glucan facilitates ovalbumin-induced allergic airway inflammation in mice: Possible role of antigen-presenting cells

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    <p>Abstract</p> <p>Background</p> <p>Although fungi have been implicated as initiating/deteriorating factors for allergic asthma, their contributing components have not been fully elucidated. We previously isolated soluble β-glucan from <it>Candida albicans </it>(CSBG) (Ohno et al., 2007). In the present study, the effects of CSBG exposure on airway immunopathology in the presence or absence of other immunogenic allergen was investigated <it>in vivo</it>, and their cellular mechanisms were analyzed both <it>in vivo </it>and <it>in vitro</it>.</p> <p>Methods</p> <p><it>In vivo</it>, ICR mice were divided into 4 experimental groups: vehicle, CSBG (25 μg/animal), ovalbumin (OVA: 2 μg/animal), and CSBG + OVA were repeatedly administered intratracheally. The bronchoalveolar lavage cellular profile, lung histology, levels of cytokines and chemokines in the lung homogenates, the expression pattern of antigen-presenting cell (APC)-related molecules in the lung digests, and serum immunoglobulin values were studied. <it>In vitro</it>, the impacts of CSBG (0–12.5 μg/ml) on the phenotype and function of immune cells such as splenocytes and bone marrow-derived dendritic cells (BMDCs) were evaluated in terms of cell proliferation, the surface expression of APC-related molecules, and OVA-mediated T-cell proliferating activity.</p> <p>Results</p> <p><it>In vivo</it>, repeated pulmonary exposure to CSBG induced neutrophilic airway inflammation in the absence of OVA, and markedly exacerbated OVA-related eosinophilic airway inflammation with mucus metaplasia in mice, which was concomitant with the amplified lung expression of Th2 cytokines and IL-17A and chemokines related to allergic response. Exposure to CSBG plus OVA increased the number of cells bearing MHC class II with or without CD80 in the lung compared to that of others. <it>In vitro</it>, CSBG significantly augmented splenocyte proliferation in the presence or absence of OVA. Further, CSBG increased the expression of APC-related molecules such as CD80, CD86, and DEC205 on BMDCs and amplified OVA-mediated T-cell proliferation through BMDCs.</p> <p>Conclusion</p> <p>CSBG potentiates allergic airway inflammation with maladaptive Th immunity, and this potentiation was associated with the enhanced activation of APCs including DC.</p

    Dual Organism Transcriptomics of Airway Epithelial Cells Interacting with Conidia of Aspergillus fumigatus

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    Background Given the complex nature of the responses that can occur in host-pathogen interactions, dual transcriptomics offers a powerful method of elucidating these interactions during infection. The gene expression patterns of Aspergillus fumigatus conidia or host cells have been reported in a number of previous studies, but each focused on only one of the interacting organisms. In the present study, we profiled simultaneously the transcriptional response of both A. fumigatus and human airway epithelial cells (AECs). Methodology 16HBE14o- transformed bronchial epithelial cells were incubated with A. fumigatus conidia at 37°C for 6 hours, followed by genome-wide transcriptome analysis using human and fungal microarrays. Differentially expressed gene lists were generated from the microarrays, from which biologically relevant themes were identified. Human and fungal candidate genes were selected for validation, using RT-qPCR, in both 16HBE14o- cells and primary AECs co-cultured with conidia. Principal Findings We report that ontologies related to the innate immune response are activated by co-incubation with A. fumigatus condia, and interleukin-6 (IL-6) was confirmed to be up-regulated in primary AECs via RT-qPCR. Concomitantly, A. fumigatus was found to up-regulate fungal pathways involved in iron acquisition, vacuolar acidification, and formate dehydrogenase activity

    PrtT-Regulated Proteins Secreted by Aspergillus fumigatus Activate MAPK Signaling in Exposed A549 Lung Cells Leading to Necrotic Cell Death

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    Aspergillus fumigatus is the most commonly encountered mold pathogen of humans, predominantly infecting the respiratory system. Colonization and penetration of the lung alveolar epithelium is a key but poorly understood step in the infection process. This study focused on identifying the transcriptional and cell-signaling responses activated in A549 alveolar carcinoma cells incubated in the presence of A. fumigatus wild-type and ΔPrtT protease-deficient germinating conidia and culture filtrates (CF). Microarray analysis of exposed A549 cells identified distinct classes of genes whose expression is altered in the presence of germinating conidia and CF and suggested the involvement of both NFkB and MAPK signaling pathways in mediating the cellular response. Phosphoprotein analysis of A549 cells confirmed that JNK and ERK1/2 are phosphorylated in response to CF from wild-type A. fumigatus and not phosphorylated in response to CF from the ΔPrtT protease-deficient strain. Inhibition of JNK or ERK1/2 kinase activity substantially decreased CF-induced cell damage, including cell peeling, actin-cytoskeleton damage, and reduction in metabolic activity and necrotic death. These results suggest that inhibition of MAPK-mediated host responses to treatment with A. fumigatus CF decreases cellular damage, a finding with possible clinical implications

    The Past and Future of Evolutionary Economics : Some Reflections Based on New Bibliometric Evidence

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    This document is the Accepted Manuscript version of the following article: Geoffrey M. Hodgson, and Juha-Antti Lamberg, ‘The past and future of evolutionary economics: some reflections based on new bibliometric evidence’, Evolutionary and Institutional Economics Review, first online 20 June 2016. The final publication is available at Springer via doi: http://dx.doi.org/10.1007/s40844-016-0044-3 © Japan Association for Evolutionary Economics 2016The modern wave of ‘evolutionary economics’ was launched with the classic study by Richard Nelson and Sidney Winter (1982). This paper reports a broad bibliometric analysis of ‘evolutionary’ research in the disciplines of management, business, economics, and sociology over 25 years from 1986 to 2010. It confirms that Nelson and Winter (1982) is an enduring nodal reference point for this broad field. The bibliometric evidence suggests that ‘evolutionary economics’ has benefitted from the rise of business schools and other interdisciplinary institutions, which have provided a home for evolutionary terminology, but it has failed to nurture a strong unifying core narrative or theory, which in turn could provide superior answers to important questions. This bibliometric evidence also shows that no strong cluster of general theoretical research immediately around Nelson and Winter (1982) has subsequently emerged. It identifies developmental problems in a partly successful but fragmented field. Future research in ‘evolutionary economics’ needs a more integrated research community with shared conceptual narratives and common research questions, to promote conversation and synergy between diverse clusters of research.Peer reviewedFinal Accepted Versio
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