14478 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• ARHGAP11A Maintains Cortical Progenitor Identity Through RHOA–ROCK Signalling During Human Brain Development

  Mammalian brain development involves coordinated progenitor amplification, migration, and differentiation. Apical progenitors (APs) establish the ventricular zone (VZ) and are key determinants of brain size and complexity. Rho-family guanosine triphosphatases (Rho GTPases) regulate cytoskeletal dynamics and AP behaviour, but how specific Rho GTPase-activating proteins (Rho GAPs) influence progenitor identity and VZ architecture remains unclear. Using human forebrain organoids, we investigated the Rho GAP ARHGAP11A in human corticogenesis. CRISPR/Cas9-mediated ARHGAP11A knockout revealed its essential role in maintaining VZ integrity. Loss of ARHGAP11A impaired neuroepithelial organisation and randomised mitotic cleavage plane orientation via the RHOA–ROCK–actin axis. This led to premature AP delamination, AP depletion, and reduced cell density and glial numbers. Pharmacological inhibition of RHOA or ROCK rescued these defects, highlighting ARHGAP11A’s role in cytoskeletal remodelling to maintain cortical progenitors. Our findings establish ARHGAP11A as a critical regulator of AP identity and VZ integrity, with broad implications for human corticogenesis.

  Study EGAS00001008322

• Prematurity and Respiratory Outcome Program: Clinical Research Center Study of Functional and Lymphocytic Markers of Respiratory Morbidity in Hyperoxic Preemies

  Approximately 550,000 babies born prematurely each year in the United States suffer from birth at a time in development when the respiratory tract and immune system would normally be protected and maintained in a naïve state. This project is a component of the NIH Prematurity and Respiratory Outcomes Program (PROP) whose goals are the identification of disease mechanisms and biomarkers to stratify premature infants, at the time of discharge, for their risk of subsequent pulmonary morbidity. This Clinical Research Center (CRC) project will investigate prematurity-dependent alterations in cellular innate and adaptive immune systems resulting in increased susceptibility to respiratory infections and environmental irritants, and leading to respiratory morbidity in the first year of life. Prior studies have established developmental (maturity) and disease-related changes in circulating and pulmonary lymphocyte populations, but a comprehensive assessment of their relationship to disease risk/outcome has not been undertaken. We hypothesize that cellular and molecular immuno-maturity is altered due to intrinsic and extrinsic factors presented by premature birth in such a way as to reduce resistance to viral infections and to promote cytotoxic damage to the lung. We will evaluate immunologic maturity by comprehensively phenotyping lymphocyte populations in peripheral blood sampled at premature delivery, at the time of discharge from the hospital and at twelve months corrected age. The lymphocytic phenotype will be analyzed particularly in the context of gestational age and maternal-fetal stressors capable of modulating oxidative stress (oxygen exposure, infection and environmental tobacco smoke exposure). Additionally, we will assess changes in the molecular phenotype of isolated CD8 lymphocytes, a cell type preferentially recruited to the lungs of premature infants and capable of contributing to disease pathogenesis, by genome-wide expression profiling, in order to uncover novel disease pathways and define a gene expression signature associated with disease risk. We propose to build a statistical model, using cellular and molecular phenotypes and additional clinical variables, for stratifying risk of lung morbidity within the first year of life. Finally, we will assess the development of the gut microbiome in the preterm subjects to correlate with the observation of development of the adaptive immune system.

  Study phs001297

• Single Cell and Spatial Transcriptomics Studies of Fibrosis in Prospective Registry in IBD Study at MGH and GI Disease and Endoscopy Registry

  Stricturing disease or fibrosis is a common complication of inflammatory bowel disease (IBD), often requiring surgical intervention. This process is caused by the abnormal deposition of extracellular matrix in the context of inflammation, and thus involves crosstalk between multiple cell types including fibroblasts and immune cells. To understand the cellular interactions involved in fibrosis, we performed single cell and spatial transcriptomic analyses of biopsy or resection samples from IBD patients, diverticulitis patients or controls.For single cell analyses, intestinal samples were processed within three hours of collection by first stripping the epithelial layer with EDTA and then enzymatically digesting the underlying tissue. Cells from both the epithelial and tissue fractions were separately loaded in two channels on a 10x Chromium controller and libraries were generated with the 3'v3 Chemistry pipeline before sequencing on an Illumina sequencer. The resulting sequence data was demultiplexed and analyzed with the CellRanger pipeline to generate raw fastq files and processed gene-count matrices for each sample.For spatial transcriptomic analyses, intestinal resection samples were snap frozen in OCT (optimal cutting temperature embedding medium). Blocks were cut into 10μm sections in a cryostat and transferred to a 10x Genomics Visium slide v1. Spatially barcoded libraries were prepared according to manufacturer's instructions and sequencing on an Illumina sequencer. The resulting sequence data was processed with the SpaceRanger pipeline to generate fastq files and processed barcode-count matrices. Using the samples deposited here, we defined 68 fine-grained cell types across the ileum and colon of control and fibrotic intestinal tissues. We show that intestinal strictures were characterized by increased immune cells - including IgG+ plasma cells and CCR7hiCD4+ T cells - and inflammatory fibroblasts. We also define the transcriptional differences associated with fibrosis, with inflammatory fibroblasts in particular showing broad changes in gene expression. Spatial transcriptomics showed that key subsets colocalize within diseased tissues and identified additional populations such as interstitial cells of Cajal and enteric neurons. Further, we mapped gene expression onto intestinal biogeography, finding that known genetic risk loci are enriched within discrete spatial modules, defined by the presence of inflammatory fibroblasts and lymphoid follicles. Altogether, our datasets chart the key transcriptomic and cellular networks in stricturing CD and highlight the spatial organization of multicellular genetic risk factors.

  Study phs003943

• HCA_Adrenal_Foetal_WSSS_RNA_SB

  The Human Cell Atlas initiative is an ambitious global research effort which aims to describe every cell in the human body across all developmental stages to generate a reference map to accelerate progress in science and medicine particularly relating to human development and disease. The initiative is led by investigators based at the Wellcome Sanger Institute and the Broad Institute of MIT and Harvard and funding support from the Wellcome and NIH. This specific project will assess human development. We aim to interrogate the cellular composition and molecular regulators underpinning development and maturation through single cell RNA-sequencing/spatial transcriptomics and computational algorithms to predict cellular developmental trajectories and cell-cell interactions. We will subsequent validate these findings in situ using allied imaging technologies e.g. immunohistochemistry and RNAscope and in vitro culture of human intestinal organoids (HIOs). This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001004089

• Prediction of plasma ctDNA fraction and prognostic implications of liquid biopsy in advanced prostate cancer

  No consensus strategies exist for prognosticating metastatic castration-resistant prostate cancer (mCRPC). Circulating tumor DNA fraction (ctDNA%) is increasingly reported by commercial and laboratory tests but its utility for risk stratification is unclear. Here, we intersect ctDNA%, treatment outcomes, and clinical characteristics across 738 plasma samples from 491 male mCRPC patients from two randomized multicentre phase II trials and a prospective province-wide blood biobanking program. ctDNA% correlates with serum and radiographic metrics of disease burden and is highest in patients with liver metastases. ctDNA% strongly predicts overall survival, progression-free survival, and treatment response independent of therapeutic context and outperformed established prognostic clinical factors. Recognizing that ctDNA-based biomarker genotyping is limited by low ctDNA% in some patients, we leverage the relationship between clinical prognostic factors and ctDNA% to develop a clinically-interpretable machine learning tool that predicts whether a patient has sufficient ctDNA% for informative ctDNA genotyping (available online: https://www.ctDNA.org). Our results affirm ctDNA% as an actionable tool for patient risk stratification and provide a practical framework for optimized biomarker testing.

  Study EGAS50000000211

• Comprehensive spatial landscape and plasticity of immunosuppressive fibroblasts in breast cancer

  Although immunosuppressive and pro-metastatic functions of FAP+ Cancer-Associated Fibroblasts (CAF) are well-established, their plasticity and spatial distribution remain poorly understood. Here, we analyze trajectory inference, deconvolute spatial transcriptomics at single-cell level and perform functional assays to generate an integrative high-resolution map of breast cancer (BC), focusing particularly on the different subpopulations within inflammatory and myofibroblastic (iCAF/myCAF) FAP+ CAF. We identify 10 spatially-organized FAP+ CAF-related cellular niches, called EcoCellTypes, which are precisely localized within tumors. Consistent with their spatial organization, we identify DPP4- and YAP1-dependent mechanisms, by which cancer cells drive the transition of the detoxification-associated inflammatory FAP+ CAF cluster (Detox-iCAF) towards immunosuppressive extracellular matrix (ECM)-producing myofibroblasts (ECM-myCAF). In turn, ECM-myCAF polarize TREM2+ macrophages and regulatory NK cells to induce immunosuppressive EcoCellTypes. FAP+ CAF subpopulations accumulate differently depending on the invasive BC status and predict invasive recurrence of ductal carcinoma in situ (DCIS), which could help in identifying low-risk DCIS patients eligible for therapeutic de-escalation.

  Study EGAS50000000220

• Circulating Tumor Cell Heterogeneity in Neuroendocrine Prostate Cancer by Single Cell Copy Number Analysis

  Neuroendocrine prostate cancer (NEPC) is an aggressive variant of prostate cancer that may arise de novo or develop from pre-existing prostate adenocarcinoma as a mechanism of treatment resistance. Combined loss of tumor suppressors RB1, TP53, PTEN are frequent in NEPC but also present in a subset of prostate adenocarcinomas. Most clinical and preclinical studies support a trans-differentiation process, whereby NEPC arises clonally from a prostate adenocarcinoma precursor during the course of treatment resistance. Here we highlight a case of NEPC with significant intra-patient heterogeneity observed across metastases. We further demonstrate how single-cell genomic analysis of circulating tumor cells combined with phenotypic evaluation of cellular diversity can be considered as a window into tumor heterogeneity in patients with advanced prostate cancer. We performed whole genome sequencing of circulating tumor cells (CTCs) from patients with castration resistant adenocarcinoma (n=4) and neuroendocrine prostate cancer (n=8). CTCs were collected via Epic Sciences platform and single CTC genomic data (n=215) generated via Illumina NextSeq500. 

  Study phs002462

• Gut microbiome profiles according to sex, body mass index and dietary fiber intake

  Findings from recent studies suggest that the community of microbes residing in the human body is important in disease etiology; however, it remains unclear whether personal factors modulate human microbial composition. Studies based on animal models indicate that differences in composition might be attributed to sex-mediated effects. We analyzed the relationship of sex, adiposity, and dietary fiber intake with gut microbial composition using fecal samples from human subjects. We explored the associations of these factors with metrics of community composition and specific taxon abundances. We found that men and women had significantly different microbial community composition and that women had reduced abundance of a major phylum. Adiposity was associated with gut microbiome composition and specifically in women but not in men. Fiber from fruits and vegetables and fiber from beans were each associated with increased abundance of specific bacterial taxa. These findings provide initial indications that sex, adiposity, and dietary fiber might play important roles in influencing the human gut microbiome. Better understanding of these factors may have significant implications for gastrointestinal health and disease prevention.

  Study phs000884

• Genome-Wide Discovery of Novel Colon Cancer Predisposing Mutations

  Cancer risk shows clear heritability, but the inherited genetic factors remain largely unknown. This project will seek to identify new genes in which mutations confer hereditary risk for early onset colorectal cancer, with important implications for both biological understanding and clinical prediction and prevention. Identifying cancer predisposing mutations can provide new biological insights and significantly impact important clinical decision making regarding treatment, surveillance and preventive approaches. Hereditary colon cancer patients commonly present to Cancer Genetics clinics, but the majority of these patients do not have identifiable mutations in known candidate genes. We have performed whole exome sequencing to discover novel colorectal cancer susceptibility genes. The patients have been recruited from the Memorial Sloan Kettering Cancer Center (PIs Kenneth Offit, Nathan Ellis, and Zsofia Stadler), and Case Western University and University Hospitals of Cleveland (PIs Joseph Willis and Sanford Markowitz). All exome sequencing was performed at the Broad Institute of Harvard and MIT; samples sequence capture was performed using Agilent SureSelect Human All Exon Kit v2 and sequencing was performed on an Illumina HiSeq 2000 or 2500.

  Study phs000824

• The spectrum of somatic mutations in high-risk acute myeloid leukemia with -7/del(7q)

  Patients with myeloid malignancies bearing high-risk cytogenetic abnormalities lack effective therapies and have a poor overall survival. -7/del(7q) is identified in half of high-risk myeloid neoplasms. We recently identified CUX1 to be a haploinsufficient myeloid tumor suppressor gene located within the commonly deleted segment of 7q22. Here we identify the spectrum of somatic mutations that co-occur with loss of CUX1 and chromosome 7 in patients with de novo acute myeloid leukemia (AML) or a therapy-related myeloid neoplasm. -7/del(7q) leukemias have a distinct mutational profile characterized by low frequencies of alterations in major leukemogenic pathways, including genes encoding transcription factors, cohesin, and DNA-methylation-related proteins. In contrast, RAS pathway activating mutations occurred in 40% of -7/del(7q) samples, a significantly higher frequency than other AMLs and higher than previously reported. As targeted therapeutics advance, our data provide guidance for which pathways are most relevant in the treatment of adverse-risk myeloid leukemia.

  Study phs000759