103 research outputs found

    Nuclear hyaluronidase 2 drives alternative splicing of CD44 pre-mRNA to determine profibrotic or antifibrotic cell phenotype.

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    This is the author accepted manuscript. The final version is available from American Association for the Advancement of Science via the DOI in this record.The cell surface protein CD44 is involved in diverse physiological processes, and its aberrant function is linked to various pathologies such as cancer, immune dysregulation, and fibrosis. The diversity of CD44 biological activity is partly conferred by the generation of distinct CD44 isoforms through alternative splicing. We identified an unexpected function for the ubiquitous hyaluronan-degrading enzyme, hyaluronidase 2 (HYAL2), as a regulator of CD44 splicing. Standard CD44 is associated with fibrotic disease, and its production is promoted through serine-arginine-rich (SR) protein-mediated exon exclusion. HYAL2 nuclear translocation was stimulated by bone morphogenetic protein 7, which inhibits the myofibroblast phenotype. Nuclear HYAL2 displaced SR proteins from the spliceosome, thus enabling HYAL2, spliceosome components (U1 and U2 small nuclear ribonucleoproteins), and CD44 pre-mRNA to form a complex. This prevented double-exon splicing and facilitated the inclusion of CD44 exons 11 and 12, which promoted the accumulation of the antifibrotic CD44 isoform CD44v7/8 at the cell surface. These data demonstrate previously undescribed mechanisms regulating CD44 alternative splicing events that are relevant to the regulation of cellular phenotypes in progressive fibrosis.Medical Research Counci

    Isolation of cytotoxic triterpenes from the mangrove plant, Scyphiphora hydrophyllacea C.F.Gaertn (Rubiaceae)

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    Purpose: To isolate active cytotoxic compounds from the hexane and chloroform  extracts of the leaves of the mangrove plant, Scyphiphora hydrophyllacea C.F. Gaertn (Rubiaceae), grown in Sri Lanka.Methods: Dried pulverized leaves of S. hydrophyllacea were extracted with hexane and chloroform. Vacuum liquid chromatography (VLC), column chromatography (size exclusion chromatography, Sephadex LH-20) and reversed phase preparative recycling high performance liquid chromatography (HPLC) techniques were used to isolate three compounds (compounds 1, 2 and 3). The structures of the isolated compounds were established with the aid of 1H, 13C and two-dimensional nuclear magnetic resonance (2D-NMR) and electron ionization-mass spectrometry (EI-MS) techniques. 3-(4,5- Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the cytotoxic effects of the compounds on oestrogen receptor positive breast (MCF-7) and non-small cell lung (NCIH- 292) cancer cells.Results: The isolated compounds were identified as oleanolic acid (1), ursolic acid (2) and eichlerianic acid (3). Ursolic acid and eichlerianic acid showed strong  cytotoxic effects {IC50- ursolic acid: 8.47 μg/mL (24 h, MCF-7), 7.78 μg/mL (24 h, NCI-H292) and eichlerianic acid: 8.86 μg/mL (24 h, MCF-7), 10.15 μg/mL (24 h, NCI-H292)} in MCF-7 and NCI-H292 cancer cells at 24, 48 and 72 h  post-incubation periods.Conclusion: Hexane and chloroform extracts of the leaves of S. hydrophyllacea yielded three compounds namely oleanolic acid, eichlerianic acid and ursolic acid. Ursolic acid and eichlerianic acid have been isolated for the first time from the leaves of S. hydrophyllacea grown in Sri Lanka and demonstrate in-vitro cytotoxic effects in oestrogen receptor positive (MCF-7) and non-small lung cancer (NCI-H-292) cells.Keywords: Scyphiphora hydrophyllacea, eichlerianic acid, ursolic acid, oleanolic acid, MCF-7, NCI-H-29

    In vitro Cytotoxic and Antioxidant Activity of Leaf Extracts of Mangrove Plant, Phoenix paludosa Roxb

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    Purpose: To investigate the anti-proliferative and antioxidant potentials of four different solvent extracts of Phoenix paludosa Roxb leaves.Methods: Four different solvent (hexane, chloroform, ethyl acetate and methanol) leaf extracts of the plant were tested for cytotoxicity against four cancer cells, viz, MCF-7 (oestrogen positive breast cancer cell line), MDA-MB-231 (triple negative breast cancer cell line), SK-BR-3 (breast adenocarcinoma) and ACHN (renal adenocarcinoma) as well as two normal cell lines, namely, HEK-293 (embryonic kidney cells) and MCF-10A (normal mammary epithelial cells)]. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and 2, 29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging assays were used to evaluate the antioxidant activity of the crude extracts.Results: The methanol extract showed the highest antioxidant activity (DPPH, half maximal inhibitory concentration (IC50) = 30.17 ± 6.21 μg/mL) and (ABTS, IC50 = 27.91 ± 3.21 μg/mL). Of the four extracts, methanol extract showed the strongest significant (p < 0.05) cytotoxicity to all four cancer cell lines at 24 and 48 h of incubation followed by the chloroform extract (IC50 of methanol extract (24 and 48 h): 36.71 ± 8.72 and 33.19 ± 5.53 μg/mL (MCF-7), 159.7 ± 32.09 and 141.9 ± 26.2 μg/mL (MDA-MB-231), 103.3 ± 18.9 and 75.39 ± 19.39 μg/mL (SKBR-3), 57.21 ± 3.72 and 43.16 ± 10.25 μg/mL (MCF-10A), 37.48 ± 5.75 and 26.99 ± 1.85 (ACHN) and 66.83 ± 14.26 and 60.34 ± 10.66 μg/mL (HEK-293)). Furthermore, the methanol extract was least cytotoxic to normal cell lines.Conclusion: The results obtained indicate that the methanol leaf extract of P. paludosa exhibit potent antioxidant and cytotoxic activities and has the potential of being developed into an anti-cancer agent.Keywords: Phoenix paludosa, antiproliferative, antioxidant, cytotoxicit

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    International criteria for acute kidney injury: advantages and remaining challenges

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    • Acute Kidney Injury (AKI) is defined using widely accepted international criteria that are based on changes in serum creatinine concentration and degree of oliguria. • AKI, when defined in this way, has a strong association with poor patient outcomes, including high mortality rates and longer hospital admissions with increased resource utilisation and subsequent chronic kidney disease. • The detection of AKI using current criteria can assist with AKI diagnosis and stratification of individual patient risk. • The diagnosis of AKI requires clinical judgement to integrate the definition of AKI with the clinical situation, to determine underlying cause of AKI, and to take account of factors that may affect performance of current definitions

    Meta Modeling for Business Process Improvement

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    Conducting business process improvement (BPI) initiatives is a topic of high priority for today’s companies. However, performing BPI projects has become challenging. This is due to rapidly changing customer requirements and an increase of inter-organizational business processes, which need to be considered from an end-to-end perspective. In addition, traditional BPI approaches are more and more perceived as overly complex and too resource-consuming in practice. Against this background, the paper proposes a BPI roadmap, which is an approach for systematically performing BPI projects and serves practitioners’ needs for manageable BPI methods. Based on this BPI roadmap, a domain-specific conceptual modeling method (DSMM) has been developed. The DSMM supports the efficient documentation and communication of the results that emerge during the application of the roadmap. Thus, conceptual modeling acts as a means for purposefully codifying the outcomes of a BPI project. Furthermore, a corresponding software prototype has been implemented using a meta modeling platform to assess the technical feasibility of the approach. Finally, the usability of the prototype has been empirically evaluated

    NOX1 loss-of-function genetic variants in patients with inflammatory bowel disease.

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    Genetic defects that affect intestinal epithelial barrier function can present with very early-onset inflammatory bowel disease (VEOIBD). Using whole-genome sequencing, a novel hemizygous defect in NOX1 encoding NAPDH oxidase 1 was identified in a patient with ulcerative colitis-like VEOIBD. Exome screening of 1,878 pediatric patients identified further seven male inflammatory bowel disease (IBD) patients with rare NOX1 mutations. Loss-of-function was validated in p.N122H and p.T497A, and to a lesser degree in p.Y470H, p.R287Q, p.I67M, p.Q293R as well as the previously described p.P330S, and the common NOX1 SNP p.D360N (rs34688635) variant. The missense mutation p.N122H abrogated reactive oxygen species (ROS) production in cell lines, ex vivo colonic explants, and patient-derived colonic organoid cultures. Within colonic crypts, NOX1 constitutively generates a high level of ROS in the crypt lumen. Analysis of 9,513 controls and 11,140 IBD patients of non-Jewish European ancestry did not reveal an association between p.D360N and IBD. Our data suggest that loss-of-function variants in NOX1 do not cause a Mendelian disorder of high penetrance but are a context-specific modifier. Our results implicate that variants in NOX1 change brush border ROS within colonic crypts at the interface between the epithelium and luminal microbes

    IMPROVE-PD Finder: A Web-Based Platform to Search and Share Peritoneal Dialysis Biobank, Registry, and Clinical Trial Metadata

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    Peritoneal dialysis (PD) is a life-sustaining kidney replacement therapy for the increasing number of people with permanent kidney failure across all age groups worldwide. Although PD potentially offers socioeconomic and performance benefits over hemodialysis, both treatments severely accelerate complications of chronic kidney disease, in particular atherosclerotic disease progression that worsens outcomes when compared with non-dialysis patients.1 Improved understanding of the underlying molecular pathogenic mechanisms should help in the design of interventions that improve outcomes.2 Current state of the art in PD research, however, faces major limitations. Although there are numerous in vitro and ex vivo studies on complex cellular and molecular networks active in PD3, 4, 5 and in vivo animal models of PD6, 7, 8 that provide in-depth pathomechanistic insights and allow identification of promising therapeutic targets,9,S1,S2 translation into clinical studies is a major challenge.S3 Patient studies that aim to substantiate experimental findings with definitive clinical outcome data are mostly small. As a result, they have not provided sufficient power to derive meaningful or clinically implementable conclusions.2 Basic PD technique has hardly changed over decades, despite high PD-related complication rates. Randomized prospective trials with hard clinical end points studied with adequate power are difficult to realize in a multifactorial setting with low patient numbers (360,000 worldwide) and are associated with high costs. To overcome these barriers intermediate end points such as PD effluent biomarkers associated (but not necessarily causally related) with hard clinical end points and composite end points are often studied.S4,S5 Equally, combining analyses of existing cohort studies and trial data through collaborative sharing might be of considerable benefit
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