940 research outputs found

    Expression Profiles of Exosomal MicroRNAs from HEV- and HCV-Infected Blood Donors and Patients:A Pilot Study

    Get PDF
    Exosomes seem to play an important role in hepatits C virus (HCV) and hepatitis E virus (HEV) infection by shielding their cargo from the host immune responses, with microRNAs being key exosomal components. Little is known about their involvement in a mixed HCV/HEV infection or at the early stages of infection, such as in asymptomatic blood donors (BDs). To obtain preliminary data, we have compared the exosomal microRNA expression profiles in four each of HCV RNA-positive, HEV RNA-positive and negative blood donors and four patients, one of whom was a rare patient with HCV/HEV co-infection. Exosomes were purified from sera by a combination of a precipitation and density gradient centrifugation and exosomal microRNA was analysed using Taqman array cards. Out of 33 deregulated miRNAs, miR-885-5p and miR-365 were upregulated in HCV BDs, miR-627-5p was downregulated in HCV BD and miR-221 was downregulated in HCV patients and BDs. In HEV infection, miR-526b appeared specifically downregulated. Six miRNAs (miR-628-3p, miR-194, miR-151-3p, miR-512-3p, miR-335 and miR-590) indicated a potential involvement in both infections. First time preliminary data on pre- and post-antiviral treatment exosomal microRNA profiles of the HEV/HCV co-infected patient revealed a pool of 77 upregulated and 43 downregulated miRNAs to be further investigated for their potential roles in these viral infections

    Reducing hepatocyte injury and necrosis in response to paracetamol using non-coding RNAs

    Get PDF
    The liver performs multiple functions within the human body. It is composed of numerous cell types, which play important roles in organ physiology. Our study centers on the major metabolic cell type of the liver, the hepatocyte, and its susceptibility to damage during drug overdose. In these studies, hepatocytes were generated from a renewable and genetically defined resource. In vitro-derived hepatocytes were extensively profiled and exposed to varying levels of paracetamol and plasma isolated from liver-failure patients, with a view to identifying noncoding microRNAs that could reduce drug- or serum-induced hepatotoxicity. We identified a novel anti-microRNA, which reduced paracetamol-induced hepatotoxicity and glutathione depletion. Additionally, we identified a prosurvival role for anti-microRNA-324 following exposure to plasma collected from liver failure patients. We believe that these studies represent an important advance for the field, demonstrating the power of stem cell-derived systems to model human biology “in a dish” and identify novel noncoding microRNAs, which could be translated to the clinic in the future. SIGNIFICANCE: The liver performs vital functions within the human body and is composed of numerous cell types. The major metabolic cell type of the liver, the hepatocyte, is susceptible to damage during drug overdose. In these studies, hepatocytes were generated from a renewable resource and exposed to varying levels of paracetamol, with a view to identifying interventions that could reduce or attenuate drug-induced liver toxicity. A novel noncoding RNA that reduced paracetamol-induced hepatocyte toxicity was identified. These findings may represent an important advance for the field

    Mapping of A(1 )conferring resistance to the aphid Amphorophora idaei and dw (dwarfing habit) in red raspberry (Rubus idaeus L.) using AFLP and microsatellite markers

    Get PDF
    BACKGROUND: Raspberry breeding programmes worldwide aim to produce improved cultivars to satisfy market demands and within these programmes there are many targets, including increased fruit quality, yield and season, and improved pest and disease resistance and plant habit. The large raspberry aphid, Amphorophora idaei, transmits four viruses and vector resistance is an objective in raspberry breeding. The development of molecular tools that discriminate between aphid resistance genes from different sources will allow the pyramiding of such genes and the development of raspberry varieties with superior pest resistance. We have raised a red raspberry (Rubus idaeus) F(1 )progeny from the cross 'Malling Jewel' × 'Malling Orion' (MJ × MO), which segregates for resistance to biotype 1 of the aphid Amphorophora idaei and for a second phenotypic trait, dwarf habit. These traits are controlled by single genes, denoted (A(1)) and (dw) respectively. RESULTS: The progeny of 94 seedlings was scored for the segregation of 95 AFLP and 22 SSR markers and a linkage map was constructed that covers a total genetic distance of 505 cM over seven linkage groups. The average linkage group length was 72.2 cM and there was an average of 17 markers per linkage group, of which at least two were codominant SSRs, allowing comparisons with previously published maps of raspberry. The two phenotypic traits, A(1 )and dw, mapped to linkage groups 3 and 6 respectively. CONCLUSION: The mapping of A(1 )will facilitate the discrimination of resistance genes from different sources and the pyramiding of aphid resistance genes in new raspberry cultivars; the mapping of dw will allow further investigations into the genetics of dwarfing habit in Rubus

    Developing Novel Host-Based Therapies Targeting Microbicidal Responses in Macrophages and Neutrophils to Combat Bacterial Antimicrobial Resistance

    Get PDF
    Antimicrobial therapy has provided the main component of chemotherapy against bacterial pathogens. The effectiveness of this strategy has, however, been increasingly challenged by the emergence of antimicrobial resistance which now threatens the sustained utility of this approach. Humans and animals are constantly exposed to bacteria and have developed effective strategies to control pathogens involving innate and adaptive immune responses. Impaired pathogen handling by the innate immune system is a key determinant of susceptibility to bacterial infection. However, the essential components of this response, specifically those which are amenable to re-calibration to improve host defense, remain elusive despite extensive research. We provide a mini-review focusing on therapeutic targeting of microbicidal responses in macrophages and neutrophils to de-stress reliance on antimicrobial therapy. We highlight pre-clinical and clinical data pointing toward potential targets and therapies. We suggest that developing focused host-directed therapeutic strategies to enhance “pauci-inflammatory” microbial killing in myeloid phagocytes that maximizes pathogen clearance while minimizing the harmful consequences of the inflammatory response merits particular attention. We also suggest the importance of One Health approaches in developing host-based approaches through model development and comparative medicine in informing our understanding of how to deliver this strategy

    The citric acid cough threshold and the ventilatory response to carbon dioxide on ascent to high altitude

    Get PDF
    SummaryVentilatory control undergoes profound changes on ascent to high altitude. We hypothesized that the fall in citric acid cough threshold seen on ascent to altitude is mediated by changes in the central control of cough and would parallel changes in central ventilatory control assessed by the hypercapnic ventilatory response (HCVR). Twenty-five healthy volunteers underwent measurements of HCVR and citric acid sensitivity at sea level and during a 9 day sojourn at 5200m. None of the subjects had any evidence of respiratory infection. Citric acid cough threshold fell significantly on ascent to 5200m. The slope, S, of the HCVR increased significantly on ascent to 5200m and during the stay at altitude. There was no correlation between citric acid sensitivity and HCVR. We conclude that the change in citric acid cough threshold seen on exposure to hypobaric hypoxia is unlikely to be mediated by changes in the central control of cough. Sensitivity to citric acid may be due to early subclinical pulmonary edema stimulating airway sensory nerve endings

    Diet modulates the relationship between immune gene expression and functional immune responses

    Get PDF
    Nutrition is vital to health and the availability of resources has long been acknowledged as a key factor in the ability to fight off parasites, as investing in the immune system is costly. Resources have typically been considered as something of a "black box", with the quantity of available food being used as a proxy for resource limitation. However, food is a complex mixture of macro- and micronutrients, the precise balance of which determines an animal's fitness. Here we use a state-space modelling approach, the Geometric Framework for Nutrition (GFN), to assess for the first time, how the balance and amount of nutrients affects an animal's ability to mount an immune response to a pathogenic infection. Spodoptera littoralis caterpillars were assigned to one of 20 diets that varied in the ratio of macronutrients (protein and carbohydrate) and their calorie content to cover a large region of nutrient space. Caterpillars were then handled or injected with either live or dead Xenorhabdus nematophila bacterial cells. The expression of nine genes (5 immune, 4 non-immune) was measured 20 h post immune challenge. For two of the immune genes (PPO and Lysozyme) we also measured the relevant functional immune response in the haemolymph. Gene expression and functional immune responses were then mapped against nutritional intake. The expression of all immune genes was up-regulated by injection with dead bacteria, but only those in the IMD pathway (Moricin and Relish) were substantially up-regulated by both dead and live bacterial challenge. Functional immune responses increased with the protein content of the diet but the expression of immune genes was much less predictable. Our results indicate that diet does play an important role in the ability of an animal to mount an adequate immune response, with the availability of protein being the most important predictor of the functional (physiological) immune response. Importantly, however, immune gene expression responds quite differently to functional immunity and we would caution against using gene expression as a proxy for immune investment, as it is unlikely to be reliable indicator of the immune response, except under specific dietary conditions. [Abstract copyright: Copyright © 2019. Published by Elsevier Ltd.
    corecore