321 research outputs found

    Role of type IV secretion systems in trafficking of virulence determinants of Burkholderia cenocepacia

    Get PDF
    Type IV secretion systems have been identified in several human pathogens including Bordetella pertussis, Helicobacter pylori, and Legionella pneumophila. These systems are responsible for the translocation of virulence proteins and/or DNA, thereby playing an important role in the pathogenesis of infection and plasticity of genomes. Burkholderia cenocepacia is an important opportunistic human pathogen, particularly in persons with cystic fibrosis (CF). Respiratory tract infection by B. cenocepacia in CF patients is often associated with a decline in respiratory function, and can result in acute systemic infection. Burkholderia cenocepacia strain K56-2 is part of the epidemic and clinically problematic ET12 lineage. Two type IV secretion systems have been identified in this strain; one system is plasmid encoded (designated the Ptw type IV secretion system) whereas the other is chromosomally encoded (designated the VirB/D type IV secretion system) and shows homology to the Agrobacterium tumefaciens VirB/D4 type IV secretion system. It was determined that the plasmid encoded Ptw system is a chimeric type IV secretion system composed of VirB/D4-like elements and F-specific subunits. More recently, it was found that this system translocates a protein effector (PtwE1) that is cytotoxic to plant cells. It was also determined that the positively charged C-terminal region of PtwE1 is important for translocation via the Ptw type IV secretion system. Strains of the epidemic B. cenocepacia PHDC lineage contain only a chromosomal VirB/D4-like type IV secretion system (designated BcVirB/D); and a putative effector protein associated with this system has been identified that has C-terminal transport signal and sequences different from the effectors of the Ptw type IV secretion system. It has also been shown that a competing plasmid substrate and a plasmid fertility inhibition factor act to render B. cenocepacia of the PHDC lineage incapable of expressing a plant phenotype. Thus, three type IV secretion systems have been identified in epidemic B. cenocepacia lineages. From two of these, an effector has been identified that has cytotoxic effects on eukaryotic cells, and at least one of these type IV secretion systems is able to translocate DNA substrates

    Detection of Genome‐Wide IGF ‐ 1R Recruitment to Enhancer and Promoter Regions of Chromatin in Clinical Prostate Cancers

    Get PDF
    Introduction: Nuclear insulin‐like growth factor‐1 receptor (IGF‐1R) undergoes IGF‐induced recruitment to cancer cell chromatin in vitro and associates with advanced prostate cancer (PCa) stage in clinical tissue, prompting this investigation of IGF‐1R chromatin recruitment in vivo. Methods: Human tissues surplus to diagnostic need were obtained from consenting patients undergoing transurethral resection of the prostate (TURP) or radical prostatectomy (RP). Initial tissue samples were processed for H3K4me1‐positive control ChIP to optimise homogenisation, fixation and ChIP conditions. Following successful method optimization, IGF‐1R and H3K4me1 ChIP‐seq was performed on six treatment‐naïve localized PCa samples, along with parallel IGF‐1R immunohistochemistry analysis. MACS2 and LanceOtron peak callers were used to identify binding sites from ChIP‐seq data and MEME Suite was used to identify an IGF‐1R binding motif. In vitro chromatin immunoprecipitation qPCR (ChIP‐qPCR) was used for ChIP‐seq data validation. Results: We identified 5743 unique IGF‐1R binding sites, with 37% within 3 kb of gene transcription start sites (TSSs). Of these sites, 72.3% coincided with enhancer mark H3K4me1, suggesting regulatory function. Motif analysis identified an IGF‐1R consensus binding motif for the first time, with a sequence resembling that of the insulin receptor and PITX2 transcription factor binding motifs, supporting functional similarities. In vitro ChIP‐qPCR confirmed IGF‐1R recruitment to a site identified in vivo in the RRM2 TSS, a gene involved in DNA replication and repair and regulated by the IGF‐axis, highlighting potential regulatory function of nuclear IGF‐1R. Conclusion: Overall, these data represent the first characterization of genome‐wide IGF‐1R recruitment in PCa tissue and are consistent with a transcriptional regulatory role, further elucidating the contribution of nuclear IGF‐1R to advanced clinical stage

    When xylarium and herbarium meet : linking Tervuren xylarium wood samples with their herbarium specimens at Meise Botanic Garden

    Get PDF
    Background: The current data paper aims to interlink the African plant collections of the Meise Botanic Garden Herbarium (BR) and the Royal Museum for Central Africa Xylarium (Tw). Complementing both collections strengthens the reference value of each institutional collection, as more complete metadata are made available and it enables increased quality control for the identification of wood specimens. Furthermore, the renewed connection enables the linking of available wood trait data with data on phenology, leaf morphology or even molecular information for many tree species, allowing assessments of performance of individual trees. In addition to studies at the interspecific level, comparisons at the intraspecific level become possible, which could lead to important new insights into resilience to and impact of global change, as well as biodiversity conservation or forest management of Central African forest ecosystems. New information: By interlinking the Tervuren Xylarium Wood database with the recently digitised herbarium of Meise Botanic Garden, we were able to establish a link between 6,621 xylarium and 9,641 herbarium records for 6,953 plant specimens. Both institutional databases were complemented with reliable specimen metadata. The Tervuren xylarium now profits from taxonomic revisions made by botanists at Meise Botanic Garden and a list of phenotypical features for woody African species can be extended with wood anatomical descriptors. New metadata from the Tw xylarium records were used to add the country of collection to 50 linked BR herbarium specimens for which this information was missing. Furthermore, metadata available from the labels on digitised BR herbarium specimens was used to update Tw xylarium records with the date of collection (817 records), collection locality (698 records), coordinates (482 records) and altitude (817 records). In conclusion, we created a reference database with reliable botanic identities which can be used in a range of studies, such as modelling analyses, community assessments or trait analyses, all framed in a spatiotemporal context. Furthermore, the linked collections hold historical reference data and specimens that can be studied in the context of global changes

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

    Get PDF
    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    Distinct regulation of hippocampal neuroplasticity and ciliary genes by corticosteroid receptors

    Get PDF
    Glucocorticoid hormones (GCs) are of critical importance for maintaining brain health, but their involvement in mental disorders is poorly understood. Here the authors show how GCs act through hippocampal mineralocorticoid and glucocorticoid receptors to impact the gene regulatory programs underpinning neuronal plasticity, ciliogenesis and behavioral adaptation

    The Meise Botanic Garden Herbarium Data Management Plan

    Get PDF
    This Data Management Plan outlines a comprehensive strategy for handling, storing, and sharing of data generated by digitisation projects of the herbarium at Meise Botanic Garden with Index Herbarium code BR. Its purpose is to establish clear guidelines for both staff and external users, specifying the terms governing data usage and storage. It aims to prioritise the FAIR principles (Findable, Accessible, Interoperable and Reusable), ensure responsible data management, facilitate long-term preservation, uphold legal and ethical obligations, all while aligning with the research excellence mission of Meise Botanic Garden. This plan serves as a guiding document to effectively and efficiently achieve these goals
    corecore