22948 results for "ega"

in 33.95 milliseconds.

• FLT3-targeting and places FLT3 as an ideal therapeutic target to selectively eradicate LSCs, while sparing HSC.

  CRISPR/Cas9 FLT3 knock-out (FLT3-KO) in human HSCs and LSCs followed by functional xenograft assays to test their ability to regenerate human hematopoiesis and leukemia, respectively. FLT3-KO in HSCs from human fetal liver, cord blood and adult bone marrow showed no impairment in multilineage hematopoiesis in primary and secondary xenografts. By contrast, FLT3-KO LSCs from 6 of 7 FLT3-ITD mutated AMLs were able to generate short-term engraftment but were completely exhausted by 12 weeks. Thus, FLT3 is essential for LSC long-term propagation. This dependency was unique to FLT3-ITD AML samples as non-FLT3-ITD AML samples generated leukemic grafts upon FLT3-KO. Transcriptomic analysis revealed that FLT3-KO induced downregulation of DNA repair and cell cycle checkpoints, uniquely in FLT3-ITD AML, but not in healthy HSCs or other AMLs. Our research highlights a critical distinction between healthy HSCs and LSCs: whereas healthy hematopoiesis proceeds unperturbed upon FLT3-KO, FLT3-ITD leukemogenesis is impaired through elimination of LSCs. This evidence underscores the necessity for more potent FLT3-targeting and places FLT3 as an ideal therapeutic target to selectively eradicate LSCs, while sparing HSC.

  Study EGAS50000000437

• Proteomic predictors of individualized nutrient-specific insulin secretion in health and disease

  Population level variation and molecular mechanisms behind insulin secretion in response to carbohydrate, protein, and fat remain uncharacterized despite ramifications for personalized nutrition. We now define prototypical insulin secretion dynamics in response to the three macronutrients in islets from 140 cadaveric donors, including those diagnosed with type 2 diabetes. We leverage the insulin response heterogeneity and use transcriptomics and proteomics to identify molecular pathways of specific nutrient responsiveness. Surprisingly, we find robust insulin secretion to fatty acid stimulus in ~8% of donors, challenging the idea that fat has negligible effects on insulin release. Distinct islet proteomes with differences in metabolic signalling networks convey this hyper-responsiveness to fat relative to carbohydrate. By comparing human islets to human embryonic stem cell-derived islet clusters, we show that, unlike glucose-responsiveness, fat hyper-responsiveness is equivalent and may be a hallmark of functionally immature cells. Our study represents the first comparison of dynamic responses to nutrients and multi-omics analysis in human insulin secreting cells. Responses of different people’s islets to carbohydrate, protein, and fat lay the groundwork for personalized nutrition.

  Study EGAS00001007241

• Context-specific regulatory genetic variation in MTOR dampens neutrophil-T cell crosstalk in pneumonia-associated sepsis, modulating disease

  Sepsis is a heterogeneous clinical syndrome with a high mortality, requiring personalised stratification strategies. Here, we characterise genetic variation that modulates MTOR, a critical regulator of metabolism and immune responses in sepsis. The effects are highly context specific, involving a regulatory element that affects MTOR expression in activated T cells with opposite direction of effect in neutrophils. We show that the G-allele of the lead variant, rs4845987, associated with decreased risk of T2D, reduces MTOR expression in T cells and improves survival in sepsis due to pneumonia, with effects specific to sepsis endotype. Using ex vivo models, we demonstrate that activated T cells promote immunosuppressive sepsis neutrophils through released cytokines, a process dampened by hypoxia and the mTOR inhibitor rapamycin. Our work demonstrates a novel epigenetic mechanism that fine-tunes MTOR transcription and T cell activity via the variant-containing regulatory element, which further exhibits an allelic effect upon vitamin C treatment. These findings reveal how genetic variation interacts with disease state to modulate immune cell-cell communication, providing a patient stratification strategy to inform more effective sepsis treatment.

  Study EGAS50000000894

• A Single-Cell and Spatial Atlas of Early Human Olfactory Development

  The human nasal region is a complex anatomical structure comprising neural crest- and placode-derived lineages, yet its developmental dynamics in humans remain poorly understood due to limited access to fetal tissue and challenges in resolving its spatial and cellular complexity. We built a single-cell and spatial transcriptomic atlas of the human fetal nasal region from 10 fetuses spanning post-conceptional weeks 7 to 12. Using snRNA-seq, we identify 34 cell types in the fetal nasal region and reconstruct lineage trajectories in the olfactory epithelium (OE). Spatial analyses uncover regionalized OE organization, dorsoventral gradients of olfactory receptors (ORs) and high-resolution OR expression. Combining snRNAseq and MERFISH, we reveal early onset of OR gene expression, with most olfactory sensory neurons (OSNs) following the one neuron-one receptor rule already during the first trimester. This work provides the first integrated molecular and spatial framework of early human nasal region and it provides an unprecedented molecular blueprint of the human olfactory system development. In addition, this study offers a foundational resource for embryologists and developmental biologists investigating sensory neurogenesis, epithelial patterning, and congenital diseases.

  Study EGAS50000001203

• Whole-genome methylation profiling of menstrual stem cells identifies novel biomarkers for endometriosis

  Endometriosis is a highly prevalent condition that remains underdiagnosed and poorly managed due to the lack of clinically validated biomarkers and limited understanding of its underlying pathophysiology. Although menstrual blood–derived stem cells (MenSCs) have been implicated in disease pathogenesis, their potential as a diagnostic source has not been systematically explored. We conducted a clinical study including 42 women (19 with endometriosis and 23 controls) to evaluate whether DNA methylation profiles from freshly isolated MenSCs could identify disease-specific biomarkers. Whole-genome DNA methylation sequencing identified differentially methylated regions (DMRs) enriched in genes associated with key features of endometriosis, including inflammation, tissue remodelling, and developmental processes. These DMRs robustly discriminated cases from controls, independently of technical and clinical confounders. Machine learning models trained and validated on these regions demonstrated strong diagnostic performance (specificity 83%, sensitivity 79%). Integration with an independent single-cell RNA sequencing dataset suggested that the identified DMRs may influence gene expression, supporting their biological relevance. Collectively, these findings highlight MenSC DNA methylation profiling as a promising, non-invasive strategy for early diagnosis and personalised management of endometriosis. (PubMed IDs will be provided once the manuscript is published.)

  Study EGAS50000001640

• Gut microbiome dynamics unravelled with metagenomics sequencing

  It has been already several years since we discovered that microbial therapeutics like Faecal Microbiota Transplantation can be used to treat Clostridium difficile infection (CDI) and Inflammatory bowel disease (IBD) with great success. The concept has challenged us to test the limits of our knowledge with the perspective to improve health in the most diverse conditions like Parkinson disease, depression, autism and obesity, just to mention a few. Note: the figure belongs to the original paper and is owned by the authors. Allyson L.Bird and colleagues from Genentech Inc. (San Francisco) recently published an interesting study building up on the key concept that “As microbial therapeutics are increasingly being tested in diverse patient populations, it is essential to understand the host and environmental factors influencing the microbiome.” The authors of this work analysed 1359 gut microbiome samples using shotgun metagenomics sequencing.  The results of the comparison done between microbiota composition across the different groups showed that biological sex is the strongest driver of diversity, while aging (age range studied: 20–69) appears to be the second factor. As smartly outlined in the authors’ own graphical abstract (figure to the left), Bacteroidota species consistently increased with donors' age while Actinobacteriota species, including Bifidobacterium, decreased. This study also integrated data from oncological patients to draw cancer-related evidences. After correcting the biases for technical and geographic differences, they found that cancer patients show significantly altered gut bacterial communities compared with their healthy counterparts. Eg. E.coli was found to be increased in cancer patients together with Bacteroidota/Firmicutes ratios. By comparing sequential samples taken from the same donors (413) within short-distance time points, the authors found that in the short term, intra-individual differences were less than the inter-individual ones, indicating a certain community stability being the norm. One of the pivotal points from this interesting study is that the data proceeds from extremely well-defined and selected donors. Specifically, the data for 949 selected healthy donors came from the Milieu Intérieur (MI) Consortium and extensive metadata, including demographic variables, serological measures, dietary information, and systemic immune profiles, are available. This precise stratification allowed for the robust detection of smaller changes, compared to former works. All sequencing data has been deposited in the EGA archive under the accession number EGAS00001004437. Enjoy this amazing open access paper published in the Experimental Journal of Medicine on January 2021.

  Blog gut-microbiome-dynamics-unravelled

• Non-canonical NF-κB signaling skews B cells away from germinal center to low-affinity effector fate

  The non-canonical (NC) NF-κB pathway is a central regulator of B-cell development and survival, yet its role during B-cell mediated adaptive responses remains uncharted. Here, we uncover an unanticipated regulatory function for NC NF-κB in shaping humoral immunity. High-resolution mapping of NC NF-kB status in B cells from human lymphoid tissues revealed low activity in germinal center B-cells (GCB) than effector subsets, suggesting a selective attenuation. Consistently, mice model harboring B-cells with enforced NC NF-κB activation revealed near- complete loss of GCB and high-affinity antibodies, following vaccination. GCB loss was not driven by intrinsic defects in formation or expansion, but by an immune-niche dysregulation marked by regulatory T-cell expansion. Mechanistically, NC NF-κB activation promoted B-cell- derived IL-10, and blocking this axis normalize the niche and rescue GCB. Concurrently, NC NF- κB signaling boosted low-affinity antibody responses by transcriptionally priming follicular B- cells for plasmacytic differentiation. Together, these findings position NC NF-κB as a tunable rheostat linking B-cell signaling to immune-niche control and humoral immunity.

  Study EGAS50000001646

• WTCCC2 Visceral Leishmaniasis (VL) samples

  A WTCCC2 project genome-wide association study for visceral leishmaniasis (VL) in individuals from India, Brazil and Sudan, genotyped on the custom Illumina 670k array. The WTCCC2 analysis of the Brazilian and Indian samples is described in Fakiola et al. [Nat Genet. 2013 Feb;45(2):208-13].It should be noted that due to expected family structure in the data, normal analyses of these data should include an estimation of the relatedness between the samples. For more details about sample collection for the project please refer to the Methods section of the paper above. The samples from India were all collected from Bihar state in northeastern India. The Brazilian samples were collected from a wide area of northern Brazil, and managed at two laboratories in Natal and Belem. For more details on the geographic distribution of the Brazil samples please see Jamieson et al. [Genes Immun. 2007 Jan;8(1):84-90]. We have not generated qc_passed or info files for the Sudanese data, a preliminary scan of the data indicated that there may be DNA quality issues with these samples.

  Study EGAS00001000773

• UK10K_OBESITY_GS

  In the UK10K project we propose a series of complementary genetic approaches to find new low frequency/rare variants contributing to disease phenotypes. These will be based on obtaining the genome wide sequence of 4000 samples from the TwinsUK and ALSPAC cohorts (at 6x sequence coverage), and the exome sequence (protein coding regions and related conserved sequence) of 6000 samples selected for extreme phenotypes. Our studies will focus primarily on cardiovascular-related quantitative traits, obesity and related metabolic traits, neurodevelopmental disorders and a limited number of extreme clinical phenotypes that will provide proof-of-concept for future familial trait sequencing. We will analyse directly quantitative traits in the cohorts and the selected traits in the extreme samples, and also use imputation down to 0.1% allele frequency to extend the analyses to further sample sets with genome wide genotype data. In each case we will investigate indels and larger structural variants as well as SNPs, and use statistical methods that combine rare variants in a locus or pathway as well as single-variant approaches. The GS samples are part of the Obesity group and will undergo exome sequencing.

  Study EGAS00001000242

• Genomic analysis of Smoothened inhibitor resistance in basal cell carcinoma

  Smoothened inhibitors are currently being investigated for the treatment of several cancers. Vismodegib is approved for the treatment of locally advanced and metastatic basal cell carcinoma (BCC). The majority of BCC patients treated with vismodegib experience significant clinical benefit, however, a small number of patients develop resistance. Knowledge of resistance mechanisms can generate predictive biomarkers and is critical for the design of additional therapeutic strategies aimed at circumventing resistance. To investigate mechanisms of resistance to vismodegib in BCC we sequenced and profiled biopsies from patients who initially responded to treatment and subsequently progressed on drug.We find that resistance is associated with re-activation of the Hedgehog (Hh) pathway through diverse mechanisms, including concurrent copy number alterations in the downstream Hh pathway components SUFU and GLI2, as well as novel SMO mutations that reduce sensitivity to vismodegib. The latter fall into two classes: those that activate SMO and those that directly affect the vismodegib-binding pocket. Additionally, we observe evidence of clonal selection of SMO mutations and intra-tumor heterogeneity of resistance mechanisms, which implies diverse and combinatorial strategies are required to overcome resistance.

  Study EGAS00001000845