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Sökning: WFRF:(Larsson Ludvig)

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1.
  • Bergenstråhle, Ludvig, et al. (författare)
  • Super-resolved spatial transcriptomics by deep data fusion
  • 2022
  • Ingår i: Nature Biotechnology. - : Nature Research. - 1087-0156 .- 1546-1696. ; 40:4, s. 476-479
  • Tidskriftsartikel (refereegranskat)abstract
    • Current methods for spatial transcriptomics are limited by low spatial resolution. Here we introduce a method that integrates spatial gene expression data with histological image data from the same tissue section to infer higher-resolution expression maps. Using a deep generative model, our method characterizes the transcriptome of micrometer-scale anatomical features and can predict spatial gene expression from histology images alone. 
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3.
  • Berglund, Emelie, et al. (författare)
  • Automation of Spatial Transcriptomics library preparation to enable rapid and robust insights into spatial organization of tissues
  • 2020
  • Ingår i: BMC Genomics. - : Springer Nature. - 1471-2164. ; 21:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Interest in studying the spatial distribution of gene expression in tissues is rapidly increasing. Spatial Transcriptomics is a novel sequencing-based technology that generates high-throughput information on the distribution, heterogeneity and co-expression of cells in tissues. Unfortunately, manual preparation of high-quality sequencing libraries is time-consuming and subject to technical variability due to human error during manual pipetting, which results in sample swapping and the accidental introduction of batch effects. All these factors complicate the production and interpretation of biological datasets.Results: We have integrated an Agilent Bravo Automated Liquid Handling Platform into the Spatial Transcriptomics workflow. Compared to the previously reported Magnatrix 8000+ automated protocol, this approach increases the number of samples processed per run, reduces sample preparation time by 35%, and minimizes batch effects between samples. The new approach is also shown to be highly accurate and almost completely free from technical variability between prepared samples.Conclusions: The new automated Spatial Transcriptomics protocol using the Agilent Bravo Automated Liquid Handling Platform rapidly generates high-quality Spatial Transcriptomics libraries. Given the wide use of the Agilent Bravo Automated Liquid Handling Platform in research laboratories and facilities, this will allow many researchers to quickly create robust Spatial Transcriptomics libraries.
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4.
  • Erickson, A, et al. (författare)
  • Spatially resolved clonal copy number alterations in benign and malignant tissue
  • 2022
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 608:7922, s. 360-
  • Tidskriftsartikel (refereegranskat)abstract
    • Defining the transition from benign to malignant tissue is fundamental to improving early diagnosis of cancer1. Here we use a systematic approach to study spatial genome integrity in situ and describe previously unidentified clonal relationships. We used spatially resolved transcriptomics2 to infer spatial copy number variations in >120,000 regions across multiple organs, in benign and malignant tissues. We demonstrate that genome-wide copy number variation reveals distinct clonal patterns within tumours and in nearby benign tissue using an organ-wide approach focused on the prostate. Our results suggest a model for how genomic instability arises in histologically benign tissue that may represent early events in cancer evolution. We highlight the power of capturing the molecular and spatial continuums in a tissue context and challenge the rationale for treatment paradigms, including focal therapy.
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5.
  • Erickson, Andrew, et al. (författare)
  • The spatial landscape of clonal somatic mutations in benign and malignant tissue
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Defining the transition from benign to malignant tissue is fundamental to improve early diagnosis of cancer. Here, we provide an unsupervised approach to study spatial genome integrity in situ to gain molecular insight into clonal relationships. We employed spatially resolved transcriptomics to infer spatial copy number variations in >120 000 regions across multiple organs, in benign and malignant tissues. We demonstrate that genome-wide copy number variation reveals distinct clonal patterns within tumours and in nearby benign tissue. Our results suggest a model for how genomic instability arises in histologically benign tissue that may represent early events in cancer evolution. We highlight the power of an unsupervised approach to capture the molecular and spatial continuums in a tissue context and challenge the rationale for treatment paradigms, including focal therapy.
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7.
  • Larsson, Ludvig, et al. (författare)
  • Spatial transcriptomics
  • 2022
  • Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 185:15, s. 2840-2840.e1
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Spatially resolved transcriptomics methodologies using RNA sequencing principles have and will continue to contribute to decode the molecular landscape of tissues. Linking quantitative sequencing data with tissue morphology empowers profiling of cellular morphology and transcription over time and space in health and disease. To view this SnapShot, open or download the PDF.
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8.
  • Muus, Christoph, et al. (författare)
  • Single-cell meta-analysis of SARS-CoV-2 entry genes across tissues and demographics
  • 2021
  • Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 27:3, s. 546-559
  • Tidskriftsartikel (refereegranskat)abstract
    • Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2(+)TMPRSS2(+) cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention. An integrated analysis of over 100 single-cell and single-nucleus transcriptomics studies illustrates severe acute respiratory syndrome coronavirus 2 viral entry gene coexpression patterns across different human tissues, and shows association of age, smoking status and sex with viral entry gene expression in respiratory cell populations.
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9.
  • Akhter, Tansim, 1967-, et al. (författare)
  • Elevated Plasma Levels of Arginines During Labor Among Women with Spontaneous Preterm Birth : A Prospective Cohort Study
  • 2024
  • Ingår i: American Journal of Reproductive Immunology. - : John Wiley & Sons. - 1046-7408 .- 1600-0897. ; 91:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Problem: Preterm birth (PTB) is a leading cause of infant mortality and morbidity. The pathogenesis of PTB is complex and involves many factors, including socioeconomy, inflammation and infection. Asymmetric dimethylarginine, ADMA and symmetric dimethylarginine, SDMA are involved in labor as inhibitors of nitric oxide, a known relaxant of the uterine smooth muscles. Arginines are scarcely studied in relation to PTB and we aimed to investigate arginines (ADMA, SDMA and L-arginine) in women with spontaneous PTB and term birth.Methods of the Study: The study was based on data from the population-based, prospective cohort BASIC study conducted in Uppsala County, Sweden, between September 2009 and November 2018. Arginines were analyzed by Ultra-High Performance Liquid Chromatography using plasma samples taken at the onset of labor from women with spontaneous PTB (n = 34) and term birth (n = 45). We also analyzed the inflammation markers CRP, TNF-R1 and TNF-R2 and GDF-15.Results: Women with spontaneous PTB had higher plasma levels of ADMA (p < 0.001), and L-Arginine (p = 0.03). In addition, inflammation marker, TNF-R1 (p = 0.01) was higher in spontaneous PTB compared to term birth. Further, in spontaneous PTB, no significant correlations could be observed when comparing levels of arginines with inflammation markers, except ADMA versus CRP.Conclusions: These findings provide novel evidence for the potential involvement of arginines in the pathogenesis of spontaneous PTB and it seems that arginine levels at labor vary independently of several inflammatory markers. Further research is warranted to investigate the potential of arginines as therapeutic targets in the prevention and management of spontaneous PTB.
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10.
  • Alrutz, Marie, et al. (författare)
  • Projektledning
  • 2013
  • Bok (populärvet., debatt m.m.)abstract
    • Projektledning är ett yrke med egen certifiering. Det pågår en spännande utveckling inom området och det blir allt viktigare att hålla sig ajour med utvecklingen.Det övergripande målet med den här handboken är att vara en ständigt aktuell heltäckande bok om projektar­bete. Innehållsmässigt täcker den både frågor som har med struktur och styrning att göra och frågor om ledning av människor och mänskliga processer i grupp. Kompetens inom projekt byggs av både kunskap och erfarenhet. Vi följer kontinuerligt aktuell forskning inom dessa områden och bjuder in intressanta forskare att medverka som författare. Vi skildrar verkliga projekt och låter erfarenheterna få plats, både de bästa erfarenheterna och de utmaningar som man tagit sig igenom.Handboken är levande och det innebär att artiklar tas bort för att ge plats för nya, i takt med att den uppdateras fortlöpande.
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11.
  • amundsen, silja, et al. (författare)
  • A comprehensive screen for SNP associations on chromosome region 5q31-33 in Swedish/Norwegian celiac disease families.
  • 2007
  • Ingår i: European Journal of Human genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 15:9, s. 980-987
  • Tidskriftsartikel (refereegranskat)abstract
    • Celiac disease (CD) is a gluten-induced enteropathy, which results from the interplay between environmental and genetic factors. There is a strong human leukocyte antigen (HLA) association with the disease, and HLA-DQ alleles represent a major genetic risk factor. In addition to HLA-DQ, non-HLA genes appear to be crucial for CD development. Chromosomal region 5q31–33 has demonstrated linkage with CD in several genome-wide studies, including in our Swedish/Norwegian cohort. In a European meta-analysis 5q31–33 was the only region that reached a genome-wide level of significance except for the HLA region. To identify the genetic variant(s) responsible for this linkage signal, we performed a comprehensive single nucleotide polymorphism (SNP) association screen in 97 Swedish/Norwegian multiplex families who demonstrate linkage to the region. We selected tag SNPs from a 16 Mb region representing the 95% confidence interval of the linkage peak. A total of 1404 SNPs were used for the association analysis. We identified several regions with SNPs demonstrating moderate single- or multipoint associations. However, the isolated association signals appeared insufficient to account for the linkage signal seen in our cohort. Collective effects of multiple risk genes within the region, incomplete genetic coverage or effects related to copy number variation are possible explanations for our findings.
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12.
  • Andersson, Alma, et al. (författare)
  • Spatial deconvolution of HER2-positive breast cancer delineates tumor-associated cell type interactions
  • 2021
  • Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • In the past decades, transcriptomic studies have revolutionized cancer treatment and diagnosis. However, tumor sequencing strategies typically result in loss of spatial information, critical to understand cell interactions and their functional relevance. To address this, we investigate spatial gene expression in HER2-positive breast tumors using Spatial Transcriptomics technology. We show that expression-based clustering enables data-driven tumor annotation and assessment of intra- and interpatient heterogeneity; from which we discover shared gene signatures for immune and tumor processes. By integration with single cell data, we spatially map tumor-associated cell types to find tertiary lymphoid-like structures, and a type I interferon response overlapping with regions of T-cell and macrophage subset colocalization. We construct a predictive model to infer presence of tertiary lymphoid-like structures, applicable across tissue types and technical platforms. Taken together, we combine different data modalities to define a high resolution map of cellular interactions in tumors and provide tools generalizing across tissues and diseases. While transcriptomics have enhanced our understanding for cancer, spatial transcriptomics enable the characterisation of cellular interactions. Here, the authors integrate single cell data with spatial information for HER2 + tumours and develop tools for the prediction of interactions between tumour-infiltrating cells.
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13.
  • Andersson, Alma, et al. (författare)
  • Spatial Deconvolution of HER2-positive Breast Tumors Reveals Novel Intercellular Relationships
  • 2020
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • In the past decades, transcriptomic studies have revolutionized cancer treatment and diagnosis. However, tumor sequencing strategies typically result in loss of spatial information, critical to understand cell interactions and their functional relevance. To address this, we investigate spatial gene expression in HER2-positive breast tumors using Spatial Transcriptomics technology. We show that expression-based clustering enables data-driven tumor annotation and assessment of intra-and interpatient heterogeneity; from which we discover shared gene signatures for immune and tumor processes. We integrate and spatially map tumor-associated types from single cell data to find: segregated epithelial cells, interactions between B and T-cells and myeloid cells, co-localization of macrophage and T-cell subsets. A model is constructed to infer presence of tertiary lymphoid structures, applicable across tissue types and technical platforms. Taken together, we combine different data modalities to define novel interactions between tumor-infiltrating cells in breast cancer and provide tools generalizing across tissues and diseases.
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14.
  • Andersson, Martin, et al. (författare)
  • Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics
  • 2017
  • Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 27:1
  • Tidskriftsartikel (refereegranskat)abstract
    • High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO2. No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5-13.8 mm/s. By this, a better control of high-pressure microfluidic platforms has been achieved.
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15.
  • Asp, Michaela, et al. (författare)
  • A Spatiotemporal Organ-Wide Gene Expression and Cell Atlas of the Developing Human Heart
  • 2019
  • Ingår i: Cell. - : CELL PRESS. - 0092-8674 .- 1097-4172. ; 179:7, s. 1647-
  • Tidskriftsartikel (refereegranskat)abstract
    • The process of cardiac morphogenesis in humans is incompletely understood. Its full characterization requires a deep exploration of the organ-wide orchestration of gene expression with a single-cell spatial resolution. Here, we present a molecular approach that reveals the comprehensive transcriptional landscape of cell types populating the embryonic heart at three developmental stages and that maps cell-type-specific gene expression to specific anatomical domains. Spatial transcriptomics identified unique gene profiles that correspond to distinct anatomical regions in each developmental stage. Human embryonic cardiac cell types identified by single-cell RNA sequencing confirmed and enriched the spatial annotation of embryonic cardiac gene expression. In situ sequencing was then used to refine these results and create a spatial subcellular map for the three developmental phases. Finally, we generated a publicly available web resource of the human developing heart to facilitate future studies on human cardiogenesis.
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16.
  • Bergenstråhle, Joseph, et al. (författare)
  • Seamless integration of image and molecular analysis for spatial transcriptomics workflows
  • 2020
  • Ingår i: BMC Genomics. - : BioMed Central. - 1471-2164. ; 21:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Recent advancements in in situ gene expression technologies constitute a new and rapidly evolving field of transcriptomics. With the recent launch of the 10x Genomics Visium platform, such methods have started to become widely adopted. The experimental protocol is conducted on individual tissue sections collected from a larger tissue sample. The two-dimensional nature of this data requires multiple consecutive sections to be collected from the sample in order to construct a comprehensive three-dimensional map of the tissue. However, there is currently no software available that lets the user process the images, align stacked experiments, and finally visualize them together in 3D to create a holistic view of the tissue. Results: We have developed an R package named STUtility that takes 10x Genomics Visium data as input and provides features to perform standardized data transformations, alignment of multiple tissue sections, regional annotation, and visualizations of the combined data in a 3D model framework. Conclusions: STUtility lets the user process, analyze and visualize multiple samples of spatially resolved RNA sequencing and image data from the 10x Genomics Visium platform. The package builds on the Seurat framework and uses familiar APIs and well-proven analysis methods. An introduction to the software package is available at https://ludvigla.github.io/STUtility_web_site/.
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17.
  • Berglund, Emelie, et al. (författare)
  • Spatial maps of prostate cancer transcriptomes reveal an unexplored landscape of heterogeneity
  • 2018
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
  • Tidskriftsartikel (refereegranskat)abstract
    • Intra-tumor heterogeneity is one of the biggest challenges in cancer treatment today. Here we investigate tissue-wide gene expression heterogeneity throughout a multifocal prostate cancer using the spatial transcriptomics (ST) technology. Utilizing a novel approach for deconvolution, we analyze the transcriptomes of nearly 6750 tissue regions and extract distinct expression profiles for the different tissue components, such as stroma, normal and PIN glands, immune cells and cancer. We distinguish healthy and diseased areas and thereby provide insight into gene expression changes during the progression of prostate cancer. Compared to pathologist annotations, we delineate the extent of cancer foci more accurately, interestingly without link to histological changes. We identify gene expression gradients in stroma adjacent to tumor regions that allow for re-stratification of the tumor microenvironment. The establishment of these profiles is the first step towards an unbiased view of prostate cancer and can serve as a dictionary for future studies.
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18.
  • Bäckström, Alexandra, et al. (författare)
  • Combinatorial gene targeting in primary human hematopoietic stem and progenitor cells
  • 2022
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The CRISPR/Cas9 system offers enormous versatility for functional genomics but many applications have proven to be challenging in primary human cells compared to cell lines or mouse cells. Here, to establish a paradigm for multiplexed gene editing in primary human cord blood-derived hematopoietic stem and progenitor cells (HSPCs), we used co-delivery of lentiviral sgRNA vectors expressing either Enhanced Green Fluorescent Protein (EGFP) or Kusabira Orange (KuO), together with Cas9 mRNA, to simultaneously edit two genetic loci. The fluorescent markers allow for tracking of either single- or double-edited cells, and we could achieve robust double knockout of the cell surface molecules CD45 and CD44 with an efficiency of ~ 70%. As a functional proof of concept, we demonstrate that this system can be used to model gene dependencies for cell survival, by simultaneously targeting the cohesin genes STAG1 and STAG2. Moreover, we show combinatorial effects with potential synergy for HSPC expansion by targeting the Aryl Hydrocarbon Receptor (AHR) in conjunction with members of the CoREST complex. Taken together, our traceable multiplexed CRISPR/Cas9 system enables studies of genetic dependencies and cooperation in primary HSPCs, and has important implications for modelling polygenic diseases, as well as investigation of the underlying mechanisms of gene interactions.
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19.
  • Carlberg, Konstantin, et al. (författare)
  • Exploring inflammatory signatures in arthritic joint biopsies with Spatial Transcriptomics
  • 2019
  • Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 9
  • Tidskriftsartikel (refereegranskat)abstract
    • Lately it has become possible to analyze transcriptomic profiles in tissue sections with retained cellular context. We aimed to explore synovial biopsies from rheumatoid arthritis (RA) and spondyloarthritis (SpA) patients, using Spatial Transcriptomics (ST) as a proof of principle approach for unbiased mRNA studies at the site of inflammation in these chronic inflammatory diseases. Synovial tissue biopsies from affected joints were studied with ST. The transcriptome data was subjected to differential gene expression analysis (DEA), pathway analysis, immune cell type identification using Xcell analysis and validation with immunohistochemistry (IHC). The ST technology allows selective analyses on areas of interest, thus we analyzed morphologically distinct areas of mononuclear cell infiltrates. The top differentially expressed genes revealed an adaptive immune response profile and T-B cell interactions in RA, while in SpA, the profiles implicate functions associated with tissue repair. With spatially resolved gene expression data, overlaid on high-resolution histological images, we digitally portrayed pre-selected cell types in silico. The RA displayed an overrepresentation of central memory T cells, while in SpA effector memory T cells were most prominent. Consequently, ST allows for deeper understanding of cellular mechanisms and diversity in tissues from chronic inflammatory diseases.
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20.
  • Carlberg, Konstantin, et al. (författare)
  • Integrated Single Cell and Spatial Transcriptomics Reveal Autoreactive Differentiated B Cells in Joints of Early Rheumatoid Arthritis
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Rheumatoid Arthritis (RA) is a prevalent autoimmune disease characterized by inflammation of peripheral joints. Patients can be subdivided by the presence or absence of Rheumatoid Factor and anti-citrullinated protein antibodies (ACPA) in their circulation. Inflammation of the joint tissue is associated with infiltration of leukocytes from the blood, which can result in generation of lymphoid structures composed of B and T cells. Previous studies have shown that both memory B cells and antibody-secreting plasma cells populate the rheumatic joint tissue when captured from established and often long-standing disease. However, it has remained unclear, whether these cells are autoreactive and whether the associated lymphoid structures are present at the site of inflammation already at the time of diagnosis. Here, we used an integrated single cell and spatial transcriptomic approach to study B and plasma cells in synovial tissue of ACPA- and ACPA+ RA patients at this early time point. We found evidence for T cell help to B cells and presence of memory B and plasma cell pools in ACPA- as well as in ACPA+ RA. Our results demonstrated common supportive microenvironments in both patient subgroups, clonal relationships between the memory B and plasma cell pools and autoreactivity within the plasma cell compartment. These findings challenge our understanding of the dynamics of local adaptive immune responses in the RA joint of ACPA- and ACPA+ patients at the time of diagnosis, with direct implications for B and T cell targeting therapies for both patient subgroups. 
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21.
  • Elfwen, Ludvig, et al. (författare)
  • Direct or subacute coronary angiography in out-of-hospital cardiac arrest (DISCO)-An initial pilot-study of a randomized clinical trial
  • 2019
  • Ingår i: Resuscitation. - : ELSEVIER IRELAND LTD. - 0300-9572 .- 1873-1570. ; 139, s. 253-261
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: The clinical importance of immediate coronary angiography, with potentially subsequent percutaneous coronary intervention (PCI), in out-of-hospital cardiac arrest (OHCA) patients without ST-elevation on the ECG is unclear. In this study, we assessed feasibility and safety aspects of performing immediate coronary angiography in a pre-specified pilot phase of the 'DIrect or Subacute Coronary angiography in Out-of-hospital cardiac arrest' (DISCO) randomized controlled trial (ClinicalTrials.gov ID: NCT02309151). Methods: Resuscitated bystander witnessed OHCA patients > 18 years without ST-elevation on the ECG were randomized to immediate coronary angiography versus standard of care. Event times, procedure related adverse events and safety variables within 7 days were recorded. Results: In total, 79 patients were randomized to immediate angiography (n = 39) or standard of care (n = 40). No major differences in baseline characteristics between the groups were found. There were no differences in the proportion of bleedings and renal failure. Three patients randomized to immediate angiography and six patients randomized to standard care died within 24 h. The median time from EMS arrival to coronary angiography was 135 min in the immediate angiography group. In patients randomized to immediate angiography a culprit lesion was found in 14/38 (36.8%) and PCI was performed in all these patients. In 6/40 (15%) patients randomized to standard of care, coronary angiography was performed before the stipulated 3 days. Conclusion: In this out-of-hospital cardiac arrest population without ST-elevation, randomization to a strategy to perform immediate coronary angiography was feasible although the time window of 120 min from EMS arrival at the scene of the arrest to start of coronary angiography was not achieved. No significant safety issues were reported.
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22.
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23.
  • Fan, Yuhang, et al. (författare)
  • Expansion spatial transcriptomics
  • 2023
  • Ingår i: Nature Methods. - : Springer Nature. - 1548-7091 .- 1548-7105. ; 20:8, s. 1179-1182
  • Tidskriftsartikel (refereegranskat)abstract
    • Capture array-based spatial transcriptomics methods have been widely used to resolve gene expression in tissues; however, their spatial resolution is limited by the density of the array. Here we present expansion spatial transcriptomics to overcome this limitation by clearing and expanding tissue prior to capturing the entire polyadenylated transcriptome with an enhanced protocol. This approach enables us to achieve higher spatial resolution while retaining high library quality, which we demonstrate using mouse brain samples. 
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24.
  • Firsova, Alexandra, et al. (författare)
  • Topographic atlas of cell states identifies regional gene expression in the adult human lung
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Single cell mRNA sequencing of the whole organ has become a popular technique to reveal rare types and subtypes of previously characterized cells as well as to distinguish and characterize gene expression of previously unknown cell types. Unsupervised clustering can reveal tens or even hundreds of variable genes that characterize cell types. Variation in gene expression is often observed within one cell type, and sometimes cannot be biologically explained without mapping of mRNA on tissue. In this study we aim to (i) map the majority of cell types of human lung, (ii) describe variability in their gene expression and (iii) relate this gene expression to cellular location and neighborhoods. Using three different spatial transcriptomics approaches, we mapped epithelial cell states of airways and submucosal gland, and defined cell type-unrelated gene expression variability along proximo-distal axis, including potential regulators and co-regulators of such cell states in the mesenchymal and immune cell niches. In addition, we mapped rare cell types, such as subtypes of neuroendocrine cells, ionocytes and tuft (brush) cells, revealing tracheal preference for ionocytes, and distal airways for GHRL-positive neuroendocrine cells. Finally, we used the created map as a reference for the diseased tissue from patients with stage II COPD and revealed perturbed cell states and COPD-specific imbalance of cell types, affecting immune and AT0 clusters. 
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25.
  • Frede, Annika, et al. (författare)
  • B cell expansion hinders the stroma-epithelium regenerative cross talk during mucosal healing
  • 2022
  • Ingår i: Immunity. - : Elsevier BV. - 1074-7613 .- 1097-4180. ; 55:12, s. 2336-
  • Tidskriftsartikel (refereegranskat)abstract
    • Therapeutic promotion of intestinal regeneration holds great promise, but defining the cellular mechanisms that influence tissue regeneration remains an unmet challenge. To gain insight into the process of mucosal healing, we longitudinally examined the immune cell composition during intestinal damage and regeneration. B cells were the dominant cell type in the healing colon, and single-cell RNA sequencing (scRNA-seq) re-vealed expansion of an IFN-induced B cell subset during experimental mucosal healing that predominantly located in damaged areas and associated with colitis severity. B cell depletion accelerated recovery upon injury, decreased epithelial ulceration, and enhanced gene expression programs associated with tissue re-modeling. scRNA-seq from the epithelial and stromal compartments combined with spatial transcriptomics and multiplex immunostaining showed that B cells decreased interactions between stromal and epithelial cells during mucosal healing. Activated B cells disrupted the epithelial-stromal cross talk required for orga-noid survival. Thus, B cell expansion during injury impairs epithelial-stromal cell interactions required for mucosal healing, with implications for the treatment of IBD.
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26.
  • Hardt, Uta, et al. (författare)
  • Integrated single cell and spatial transcriptomics reveal autoreactive differentiated B cells in joints of early rheumatoid arthritis
  • 2022
  • Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • B cells play a significant role in established Rheumatoid Arthritis (RA). However, it is unclear to what extent differentiated B cells are present in joint tissue already at the onset of disease. Here, we studied synovial biopsies (n = 8) captured from untreated patients at time of diagnosis. 3414 index-sorted B cells underwent RNA sequencing and paired tissue pieces were subjected to spatial transcriptomics (n = 4). We performed extensive bioinformatics analyses to dissect the local B cell composition. Select plasma cell immunoglobulin sequences were expressed as monoclonal antibodies and tested by ELISA. Memory and plasma cells were found irrespective of autoantibody status of the patients. Double negative memory B cells were prominent, but did not display a distinct transcriptional profile. The tissue architecture implicate both local B cell maturation via T cell help and plasma cell survival niches with a strong CXCL12-CXCR4 axis. The immunoglobulin sequence analyses revealed clonality between the memory B and plasma cell pools further supporting local maturation. One of the plasma cell-derived antibodies displayed citrulline autoreactivity, demonstrating local autoreactive plasma cell differentiation in joint biopsies captured from untreated early RA. Hence, plasma cell niches are not a consequence of chronic inflammation, but are already present at the time of diagnosis.
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27.
  • Hasselquist, David, et al. (författare)
  • Longitudinal Analysis of Wildcard Certificates in the WebPKI
  • 2023
  • Ingår i: 2023 IFIP NETWORKING CONFERENCE, IFIP NETWORKING. - : IEEE. - 9783903176577 - 9798350339383
  • Konferensbidrag (refereegranskat)abstract
    • The use of wildcard certificates and multi-domain certificates can impact how sensitive a certificate is to attacks and how many (sub)domains and machines may be impacted if a private key is compromised. Unfortunately, there are no globally agreed-upon best practices for these certificate types and the recommendations have changed many times over the years. In this paper, we present a 10-year longitudinal analysis of the usage of wildcard certificates and multi-domain certificates on the internet. Our analysis captures and highlights substantial differences in the heterogenous wildcard and multi-domain certificate practices. The results also show that there are several ways that CAs and domain owners have chosen to improve their practices, with many appearing to reduce the number of domains (and subdomains) for which each certificate is responsible.
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28.
  • Hildebrandt, Franziska, 1994-, et al. (författare)
  • Spatial Transcriptomics to define transcriptional patterns of zonation and structural components in the mouse liver
  • 2021
  • Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Reconstruction of heterogeneity through single cell transcriptional profiling has greatly advanced our understanding of the spatial liver transcriptome in recent years. However, global transcriptional differences across lobular units remain elusive in physical space. Here, we apply Spatial Transcriptomics to perform transcriptomic analysis across sectioned liver tissue. We confirm that the heterogeneity in this complex tissue is predominantly determined by lobular zonation. By introducing novel computational approaches, we enable transcriptional gradient measurements between tissue structures, including several lobules in a variety of orientations. Further, our data suggests the presence of previously transcriptionally uncharacterized structures within liver tissue, contributing to the overall spatial heterogeneity of the organ. This study demonstrates how comprehensive spatial transcriptomic technologies can be used to delineate extensive spatial gene expression patterns in the liver, indicating its future impact for studies of liver function, development and regeneration as well as its potential in pre-clinical and clinical pathology. Global transcriptional differences across lobular units in the liver remain unknown. Here the authors perform spatial transcriptomics of liver tissue to delineate transcriptional differences in physical space, confirm lobular zonation along transcriptional gradients and suggest the presence of previously uncharacterized structures within liver tissue.
  •  
29.
  • Ji, Andrew L., et al. (författare)
  • Multimodal Analysis of Composition and Spatial Architecture in Human Squamous Cell Carcinoma
  • 2020
  • Ingår i: Cell. - : Cell Press. - 0092-8674 .- 1097-4172. ; 182:2, s. 497-
  • Tidskriftsartikel (refereegranskat)abstract
    • To define the cellular composition and architecture of cutaneous squamous cell carcinoma (cSCC), we combined single-cell RNA sequencing with spatial transcriptomics and multiplexed ion beam imaging from a series of human cSCCs and matched normal skin. cSCC exhibited four tumor subpopulations, three recapitulating normal epidermal states, and a tumor-specific keratinocyte (TSK) population unique to cancer, which localized to a fibrovascular niche. Integration of single-cell and spatial data mapped ligand-receptor networks to specific cell types, revealing TSK cells as a hub for intercellular communication. Multiple features of potential immunosuppression were observed, including T regulatory cell (Treg) co-localization with CD8 T cells in compartmentalized tumor stroma. Finally, single-cell characterization of human tumor xenografts and in vivo CRISPR screens identified essential roles for specific tumor subpopulation-enriched gene networks in tumorigenesis. These data define cSCC tumor and stromal cell subpopulations, the spatial niches where they interact, and the communicating gene networks that they engage in cancer.
  •  
30.
  • Kvastad, Linda, et al. (författare)
  • The spatial landscape of transcriptomes and genomes in pediatric brain tumors
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Treatment of pediatric brain tumors is continually being improved; still, there is a great need for new treatment options. Here we explore the spatial transcriptomic and genomic landscape in a cohort of pediatric brain tumors using a new generation of unbiased methodologies. We demonstrate the gene expression patterns of the essential cancer-related gene programs of epithelial-to-mesenchymal transition (EMT), the reverse process mesenchymal-to-epithelial transition (MET), and tumor microenvironment (TME) observations through microglia. Furthermore, we identify the gene expression of SPP1 by microglia in the TME as a potential prognostic mRNA marker - in pediatric brain tumor relapse patients.
  •  
31.
  • Kvastad, Linda, et al. (författare)
  • The spatial RNA integrity number assay for in situ evaluation of transcriptome quality
  • 2021
  • Ingår i: Communications Biology. - : Springer Nature. - 2399-3642. ; 4:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The RNA integrity number (RIN) is a frequently used quality metric to assess the completeness of rRNA, as a proxy for the corresponding mRNA in a tissue. Current methods operate at bulk resolution and provide a single average estimate for the whole sample. Spatial transcriptomics technologies have emerged and shown their value by placing gene expression into a tissue context, resulting in transcriptional information from all tissue regions. Thus, the ability to estimate RNA quality in situ has become of utmost importance to overcome the limitation with a bulk rRNA measurement. Here we show a new tool, the spatial RNA integrity number (sRIN) assay, to assess the rRNA completeness in a tissue wide manner at cellular resolution. We demonstrate the use of sRIN to identify spatial variation in tissue quality prior to more comprehensive spatial transcriptomics workflows. Kvastad et al. develop the spatial RNA Integrity Number (sRIN) assay that evaluates the RNA integrity at cellular resolution. This method improves the resolution of a similar method called the RNA Integrity Number (RIN), demonstrating spatial variation in the quality of RNA samples.
  •  
32.
  • Lagedal, Rickard, et al. (författare)
  • Design of DISCO—Direct or Subacute Coronary Angiography in Out-of-Hospital Cardiac Arrest study
  • 2018
  • Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 197, s. 53-61
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Acute coronary syndrome is a common cause of out-of-hospital cardiac arrest (OHCA). In patients with OHCA presenting with ST elevation, immediate coronary angiography and potential percutaneous coronary intervention (PCI) after return of spontaneous circulation are recommended. However, the evidence for this invasive strategy in patients without ST elevation is limited. Observational studies have shown a culprit coronary artery occlusion in about 30% of these patients, indicating the electrocardiogram's (ECG's) limited sensitivity. The aim of this study is to determine whether immediate coronary angiography and subsequent PCI will provide outcome benefits in OHCA patients without ST elevation. Methods/design We describe the design of the DIrect or Subacute Coronary angiography in Out-of-hospital cardiac arrest study (DISCO)—a pragmatic national, multicenter, randomized, clinical study. OHCA patients presenting with no ST elevation on their first recorded ECG will be randomized to a strategy of immediate coronary angiography or to standard of care with admission to intensive care and angiography after 3 days at the earliest unless the patient shows signs of acute ischemia or hemodynamic instability. Primary end point is 30-day survival. An estimated 1,006 patients give 80% power (α =.05) to detect a 20% improved 30-day survival rate from 45% to 54%. Secondary outcomes include good neurologic recovery at 30 days and 6 months, and cognitive function and cardiac function at 6 months. Conclusion This randomized clinical study will evaluate the effect of immediate coronary angiography after OHCA on 30-day survival in patients without ST elevation on their first recorded ECG.
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33.
  • Larsson, Christer, et al. (författare)
  • Prognostic implications of the expression levels of different immunoglobulin heavy chain-encoding RNAs in early breast cancer
  • 2020
  • Ingår i: npj Breast Cancer. - : Springer Science and Business Media LLC. - 2374-4677. ; 6:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The extent and composition of the immune response in a breast cancer is one important prognostic factor for the disease. The aim of the current work was to refine the analysis of the humoral component of an immune response in breast tumors by quantifying mRNA expression of different immunoglobulin classes and study their association with prognosis. We used RNA-Seq data from two local population-based breast cancer cohorts to determine the expression of IGJ and immunoglobulin heavy (IGH) chain-encoding RNAs. The association with prognosis was investigated and public data sets were used to corroborate the findings. Except for IGHE and IGHD, mRNAs encoding heavy chains were generally detected at substantial levels and correlated with other immune-related genes. High IGHG1 mRNA was associated with factors related to poor prognosis such as estrogen receptor negativity, HER2 amplification, and high grade, whereas high IGHA2 mRNA levels were primarily associated with lower age at diagnosis. High IGHA2 and IGJ mRNA levels were associated with a more favorable prognosis both in univariable and multivariable Cox models. When adjusting for other prognostic factors, high IGHG1 mRNA levels were positively associated with improved prognosis. To our knowledge, these results are the first to demonstrate that expression of individual Ig class types has prognostic implications in breast cancer.
  •  
34.
  • Larsson, Ludvig (författare)
  • Mapping Transcriptomes in Tissues
  • 2023
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Over the past few decades, the advent of pioneering biotechnological methods has allowed scientists to analyze the molecular components of multicellular organisms with remarkable precision. The field of transcriptomics has witnessed a rapid development of technologies for gene expression profiling of biological samples. These gene expression profiles offer crucial insights into biological processes that underlie organism development, homeostasis, and disease-causing dysregulation. Modern transcriptomics technologies can profile samples at various degrees of precision and resolution, and when combined, they contribute to a comprehensive understanding of the complex molecular mechanisms that shape entire organisms. Some of these molecular mechanisms occur at the microscopic scale, controlled by communication between nearby cells. Other mechanisms depend on coordinated efforts between large networks of cells organized into tissues and organs. Cells, tissues and organs represent hierarchical levels of structural organization, and each level plays a vital role in the proper functioning of the organism. Gene expression profiling technologies yield comprehensive data that can be harnessed to explore and characterize biological phenomena within and across these structural levels. The central theme of this thesis revolves around the use of experimental technologies and computational methods in the field of transcriptomics to enhance our understanding of multicellular life. Particular attention is directed at a technology known as Visium, which has held an important position in the field in recent years. The research articles included in this thesis demonstrate the applications of Visium and related technologies in biological research.In article I, we present a computational toolbox for processing, analyzing, and visualizing Visium data, assembled into an open-source package written in the R programming language. The package facilitates the characterization of gene expression profiles in tissue sections and seamlessly integrates expression data with corresponding histological images. This computational framework was used extensively for the data analyses presented in articles II, III and IV and the articles listed in the extended list of publications.In article II, we report one of the first spatiotemporal, transcriptomics atlases of the developing human heart. The atlas encompasses three developmental time points during the first trimester, and is constructed from gene expression data from isolated cells and intact tissue sections. Joint analysis of this data enabled characterization of the transcriptomic profiles and the cellular composition of anatomical domains within the heart, illuminating biological processes that underlie cardiac morphogenesis in humans.Article III constitutes a study of the transcriptomic landscape of the murine colon generated using spatially resolved transcriptomics. By folding the organ into a roll, we successfully obtained tissue sections covering the entire colon, enabling organ-wide transcriptomic profiling. Sections were acquired from a healthy colon and a colon recovering from damage due to treatment with a tissue-damaging substance. Data-driven analysis of the healthy colon unveiled a previously undiscovered molecular regionalization from the proximal to distal parts. In the recovering colon, we observed dramatic alterations in the distal tissues, while the proximal parts remained more similar to the healthy colon. In the injured distal colon, we mapped multiple gene expression programs associated with distinct biological responses to tissue injury.In article IV, we introduce an experimental protocol that makes the Visium method compatible with fresh frozen tissue samples with low RNA quality. The protocol was tested on human prostate cancer, lung, colon, small intestine and pediatric brain tumor tissue samples, as well as mouse brain and cartilage tissue samples. Together, these tissue samples represented a wide selection of specimens with varying composition and RNA quality. Through comparative analyses, we demonstrated that the proposed experimental protocol surpassed the standard Visium protocol in performance for samples with low to moderate RNA integrity.Finally, in article V, we present an updated R package for Visium data analysis. This R package builds upon the work presented in article I, but offers a more versatile and efficient computational framework. The package features web-based tools for interactive data exploration, image processing methods and methods to map cell types in tissue sections. Additionally, it includes several spatially aware analysis methods that incorporate information about distances between measurements to investigate biological phenomena that exhibit spatial patterns.
  •  
35.
  • Larsson, Ludvig, et al. (författare)
  • Semla : a versatile toolkit for spatially resolved transcriptomics analysis and visualization
  • 2023
  • Ingår i: Bioinformatics. - : Oxford University Press (OUP). - 1367-4803 .- 1367-4811. ; 39:10
  • Tidskriftsartikel (refereegranskat)abstract
    • SUMMARY: Spatially resolved transcriptomics technologies generate gene expression data with retained positional information from a tissue section, often accompanied by a corresponding histological image. Computational tools should make it effortless to incorporate spatial information into data analyses and present analysis results in their histological context. Here, we present semla, an R package for processing, analysis, and visualization of spatially resolved transcriptomics data generated by the Visium platform, that includes interactive web applications for data exploration and tissue annotation. AVAILABILITY AND IMPLEMENTATION: The R package semla is available on GitHub (https://github.com/ludvigla/semla), under the MIT License, and deposited on Zenodo (https://doi.org/10.5281/zenodo.8321645). Documentation and tutorials with detailed descriptions of usage can be found at https://ludvigla.github.io/semla/.
  •  
36.
  • Larsson, Ludvig, 1991- (författare)
  • Semla: A versatile toolkit for spatially resolved transcriptomics analysis and visualization
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Spatially resolved transcriptomics technologies generate gene expression data with retained positional information from a tissue section, often accompanied by a corresponding histological image. Computational tools should make it effortless to incorporate spatial information into data analyses and present analysis results in their histological context. Here, we present semla, an R package for processing, analysis, and visualization of spatially resolved transcriptomics data, which includes interactive web applications for data exploration and tissue annotation.
  •  
37.
  • Larsson, Ludvig, et al. (författare)
  • Spatially resolved transcriptomics adds a new dimension to genomics
  • 2021
  • Ingår i: Nature Methods. - : NATURE RESEARCH. - 1548-7091 .- 1548-7105. ; 18:1, s. 15-18
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • As single-cell omics continue to advance, the field of spatially resolved transcriptomics has emerged with a set of experimental and computational methods to map out the positions of cells and their gene expression profiles in space. Here we summarize current transcriptome-wide and sequencing-based methodologies and their applications in genomics research.
  •  
38.
  • Larsson, Oscar, 1978- (författare)
  • Polarization characteristics in polyelectrolyte thin film capacitors : Targeting field-effect transistors and sensors
  • 2009
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Polymers are very attractive materials that can be tailored for specific needs and functionality. They can for instance be made electrically insulating or (semi)conducting, with specific mechanical properties. Polymers are often processable from a solution, which enables the use of low-cost manufacturing techniques to fabricate polymer devices. Polymer-based electronic and electrochemical devices and sensors have been developed.This thesis is related to the polarization characteristics in polyelectrolyte thin film capacitor structures. The polarization characteristics have been analyzed at various humidity levels for polyelectrolyte capacitors alone and when incorporated as the gate-insulating material in polyelectrolyte-gated organic field-effect transistors. Both limitations and possibilities of this class of transistors have been identified. Also, a concept for wireless readout of a passively operated humidity sensor circuit is demonstrated. The sensing mechanism of this sensor is related to the polarization in a polyelectrolyte thin film capacitor. This sensor circuit can be manufactured entirely with common printing technologies of today and can be integrated into a low-cost passive sensor label.
  •  
39.
  • Lázár, Enikő, et al. (författare)
  • Spatial Dynamics of the Developing Human Heart
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Heart development relies on a topologically defined interplay between a diverse array of cardiac cells. We finely curated spatial and single-cell measurements with subcellular imaging-based transcriptomics validation to explore spatial dynamics during early human cardiogenesis. Analyzing almost 80,000 individual cells and 70,000 spatially barcoded tissue regions between the 5.5th and 14th postconceptional weeks, we identified 31 coarse- and 72 fine-grained cell states and mapped them to highly resolved cardiac cellular niches. We provide novel insight into the development of the cardiac pacemaker-conduction system, heart valves, and atrial septum, and decipher heterogeneity of the hitherto elusive cardiac fibroblast population. Furthermore, we describe the formation of cardiac autonomic innervation and present the first spatial account of chromaffin cells in the fetal human heart. In summary, our study delineates the cellular and molecular landscape of the developing heart’s architecture, offering links to genetic causes of heart disease.
  •  
40.
  • Li, Xiaofei, et al. (författare)
  • Profiling spatiotemporal gene expression of the developing human spinal cord and implications for ependymoma origin
  • 2023
  • Ingår i: Nature Neuroscience. - : Springer Nature. - 1097-6256 .- 1546-1726. ; 26:5, s. 891-901
  • Tidskriftsartikel (refereegranskat)abstract
    • The authors created a comprehensive developmental cell atlas for spatiotemporal gene expression of the human spinal cord, revealed species-specific regulation during development and used the atlas to infer novel markers for pediatric ependymomas. The spatiotemporal regulation of cell fate specification in the human developing spinal cord remains largely unknown. In this study, by performing integrated analysis of single-cell and spatial multi-omics data, we used 16 prenatal human samples to create a comprehensive developmental cell atlas of the spinal cord during post-conceptional weeks 5-12. This revealed how the cell fate commitment of neural progenitor cells and their spatial positioning are spatiotemporally regulated by specific gene sets. We identified unique events in human spinal cord development relative to rodents, including earlier quiescence of active neural stem cells, differential regulation of cell differentiation and distinct spatiotemporal genetic regulation of cell fate choices. In addition, by integrating our atlas with pediatric ependymomas data, we identified specific molecular signatures and lineage-specific genes of cancer stem cells during progression. Thus, we delineate spatiotemporal genetic regulation of human spinal cord development and leverage these data to gain disease insight.
  •  
41.
  • Lopez de Lapuente Portilla, Aitzkoa, et al. (författare)
  • Genome-wide association study on 13 167 individuals identifies regulators of blood CD34+cell levels
  • 2022
  • Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 139:11, s. 1659-1669
  • Tidskriftsartikel (refereegranskat)abstract
    • Stem cell transplantation is a cornerstone in the treatment of blood malignancies. The most common method to harvest stem cells for transplantation is by leukapheresis, requiring mobilization of CD34+ hematopoietic stem and progenitor cells (HSPCs) from the bone marrow into the blood. Identifying the genetic factors that control blood CD34+ cell levels could reveal new drug targets for HSPC mobilization. Here we report the first large-scale, genome-wide association study on blood CD34+ cell levels. Across 13 167 individuals, we identify 9 significant and 2 suggestive associations, accounted for by 8 loci (PPM1H, CXCR4, ENO1-RERE, ITGA9, ARHGAP45, CEBPA, TERT, and MYC). Notably, 4 of the identified associations map to CXCR4, showing that bona fide regulators of blood CD34+ cell levels can be identified through genetic variation. Further, the most significant association maps to PPM1H, encoding a serine/threonine phosphatase never previously implicated in HSPC biology. PPM1H is expressed in HSPCs, and the allele that confers higher blood CD34+ cell levels downregulates PPM1H. Through functional fine-mapping, we find that this downregulation is caused by the variant rs772557-A, which abrogates an MYB transcription factor–binding site in PPM1H intron 1 that is active in specific HSPC subpopulations, including hematopoietic stem cells, and interacts with the promoter by chromatin looping. Furthermore, PPM1H knockdown increases the proportion of CD34+ and CD34+90+ cells in cord blood assays. Our results provide the first large-scale analysis of the genetic architecture of blood CD34+ cell levels and warrant further investigation of PPM1H as a potential inhibition target for stem cell mobilization.
  •  
42.
  • Lopez de Lapuente Portilla, Aitzkoa, et al. (författare)
  • Genome-wide association study on 13,167 individuals identifies regulators of hematopoietic stem and progenitor cell levels in human blood
  • 2021
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Understanding how hematopoietic stem and progenitor cells (HSPCs) are regulated is of central importance for the development of new therapies for blood disorders and stem cell transplantation. To date, HSPC regulation has been extensively studied in vitro and in animal models, but less is known about the mechanisms in vivo in humans. Here, in a genome-wide association study on 13,167 individuals, we identify 9 significant and 2 suggestive DNA sequence variants that influence HSPC (CD34+) levels in human blood. The identified loci associate with blood disorders, harbor known and novel HSPC genes, and affect gene expression in HSPCs. Interestingly, our strongest association maps to the PPM1H gene, encoding an evolutionarily conserved serine/threonine phosphatase never previously implicated in stem cell biology. PPM1H is expressed in HSPCs, and the allele that confers higher blood CD34+ cell levels downregulates PPM1H. By functional fine-mapping, we find that this downregulation is caused by the variant rs772557-A, which abrogates a MYB transcription factor binding site in PPM1H intron 1 that is active in specific HSPC subpopulations, including hematopoietic stem cells, and interacts with the promoter by chromatin looping. Furthermore, rs772557-A selectively increases HSPC subpopulations in which the MYB site is active, and PPM1H shRNA- knockdown increased CD34+ and CD34+90+ cell proportions in umbilical cord blood cultures. Our findings represent the first large-scale association study on a stem cell trait, illuminating HSPC regulation in vivo in humans, and identifying PPM1H as a novel inhibition target that can potentially be utilized clinically to facilitate stem cell harvesting for transplantation.
  •  
43.
  • Lopez de Lapuente Portilla, Aitzkoa, et al. (författare)
  • Identification of regulators of hematopoietic stem and progenitor cells in vivo in humans using population genetics
  • 2020
  • Konferensbidrag (refereegranskat)abstract
    • Introduction: Understanding how hematopoietic stem- and progenitor cells (HSPCs) are regulated is of central importance for the development of new therapies for blood disorders and for regenerative medicine. Traditionally, however, HSPC regulation has been studied in model systems, and little is known about the situation in vivo in humans. Methods: To learn how HSPCs are regulated under native conditions in humans, we carried out a first large-scale genome-wide association study on CD34+ cells, representing HSPCs in blood. We used circulating CD34+ levels as a proxy trait to expose regulators of key phenomena like HSPC pool size, migration, and early differentiation. We created a unique phenotyping platform based on high-throughput, high-resolution flow-cytometry and machine learning-based algorithms for automated flow data analysis, and quantified CD34+ cells in 9,936 adults.Results: We identified 8 genome-wide (P<5x10-8) and 20 suggestive loci (P<5x10-6) associated with CD34+ levels. The two strongest were the HSPC migration receptor CXCR4 and a novel protein phosphatase never previously implicated in stem cell biology. Using eQTL, ATAC-seq, and promoter capture Hi-C analysis in isolated HSPCs, we pinpoint likely causal variants, including variants in distant regulatory elements selectively active in specific HSPC subpopulations. Furthermore, shRNA knockdown in primary CD34+ cells supports that some of the identified genes affect CD34+ proliferation and differentiation.Conclusions: We report the first large-scale analysis of the genetic architecture of HSPC regulation, with potential implications for stem cell transplantation and the treatment of hematologic malignancies.Grant information: European Research Council, Swedish Research Council, Swedish Cancer Society.
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44.
  • Luecken, Malte D., et al. (författare)
  • The discovAIR project : a roadmap towards the Human Lung Cell Atlas
  • 2022
  • Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 60:2
  • Forskningsöversikt (refereegranskat)abstract
    • The Human Cell Atlas (HCA) consortium aims to establish an atlas of all organs in the healthy human body at single-cell resolution to increase our understanding of basic biological processes that govern development, physiology and anatomy, and to accelerate diagnosis and treatment of disease. The Lung Biological Network of the HCA aims to generate the Human Lung Cell Atlas as a reference for the cellular repertoire, molecular cell states and phenotypes, and cell-cell interactions that characterise normal lung homeostasis in healthy lung tissue. Such a reference atlas of the healthy human lung will facilitate mapping the changes in the cellular landscape in disease. The discovAIR project is one of six pilot actions for the HCA funded by the European Commission in the context of the H2020 framework programme. discovAIR aims to establish the first draft of an integrated Human Lung Cell Atlas, combining single-cell transcriptional and epigenetic profiling with spatially resolving techniques on matched tissue samples, as well as including a number of chronic and infectious diseases of the lung. The integrated Human Lung Cell Atlas will be available as a resource for the wider respiratory community, including basic and translational scientists, clinical medicine, and the private sector, as well as for patients with lung disease and the interested lay public. We anticipate that the Human Lung Cell Atlas will be the founding stone for a more detailed understanding of the pathogenesis of lung diseases, guiding the design of novel diagnostics and preventive or curative interventions.
  •  
45.
  • Mirzazadeh, Reza, et al. (författare)
  • Spatially resolved transcriptomic profiling of degraded and challenging fresh frozen samples
  • 2023
  • Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Spatially resolved transcriptomics has enabled precise genome-wide mRNA expression profiling within tissue sections. The performance of methods targeting the polyA tails of mRNA relies on the availability of specimens with high RNA quality. Moreover, the high cost of currently available spatial resolved transcriptomics assays requires a careful sample screening process to increase the chance of obtaining high-quality data. Indeed, the upfront analysis of RNA quality can show considerable variability due to sample handling, storage, and/or intrinsic factors. We present RNA-Rescue Spatial Transcriptomics (RRST), a workflow designed to improve mRNA recovery from fresh frozen specimens with moderate to low RNA quality. First, we provide a benchmark of RRST against the standard Visium spatial gene expression protocol on high RNA quality samples represented by mouse brain and prostate cancer samples. Then, we test the RRST protocol on tissue sections collected from five challenging tissue types, including human lung, colon, small intestine, pediatric brain tumor, and mouse bone/cartilage. In total, we analyze 52 tissue sections and demonstrate that RRST is a versatile, powerful, and reproducible protocol for fresh frozen specimens of different qualities and origins. 
  •  
46.
  • Papmehl-Dufay, Ludvig, 1976- (författare)
  • Shaping an identity : Pitted Ware pottery and potters in southeast Sweden
  • 2006
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The thesis is concerned with pottery and culture during the Middle Neolithic (c. 3300 – 2300 cal BC) in southeast Sweden. Its purpose is to investigate and discuss the significance of pottery in the Pitted Ware culture, particularly on the island of Öland in the Baltic Sea. The history of research concerning this subject area is recounted and the known Neolithic remains from the island of Öland are reviewed. The two Pitted Ware sites so far excavated on the island, Köpingsvik and Ottenby Royal Manor, are presented in detail, and ceramics from these two sites are used in the pottery analysis that makes up the empirical core of the work. The assemblages are approached by similar methods and by posing similar questions, and the analytical methods used include recording of the large ceramic assemblages (aspects of design), microscopic analysis of ceramic thin sections and raw clay samples (aspects of raw material use and pottery technology) and lipid residue analysis performed on extracts from pulverised ceramic ware (aspects of pottery use). The results clearly point to a rather elaborate and socially embedded ceramic craft tradition, with a strong preference for decorated vessels and clearly defined ideas on how the pots should be produced and what they should look like. The technological analysis revealed a rather complicated and restrictive raw material situation, with which the potters coped partly by developing local tempering traditions. The functional analysis revealed a striking variability in pottery use between the two sites. The various differences in pottery observed between the two sites are discussed in terms of local sub-traditions within the overall Pitted Ware ceramic tradition, that may have developed through the work of individual potters and contacts with different areas and groups of people. In this way an attempt is made to view pottery and the ceramic craft in the Pitted Ware culture from a more dynamic perspective.
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47.
  •  
48.
  • Parigi, Sara M., et al. (författare)
  • The spatial transcriptomic landscape of the healing mouse intestine following damage
  • 2022
  • Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The colon is comprised of specialized cells that interact with each other to function, however, the molecular regionalization of the colon is incompletely understood. Here, the authors use spatial transcriptomics to generate a publicly available resource defining the transcriptomic regionalization of the colon during steady state and mucosal healing. The intestinal barrier is composed of a complex cell network defining highly compartmentalized and specialized structures. Here, we use spatial transcriptomics to define how the transcriptomic landscape is spatially organized in the steady state and healing murine colon. At steady state conditions, we demonstrate a previously unappreciated molecular regionalization of the colon, which dramatically changes during mucosal healing. Here, we identified spatially-organized transcriptional programs defining compartmentalized mucosal healing, and regions with dominant wired pathways. Furthermore, we showed that decreased p53 activation defined areas with increased presence of proliferating epithelial stem cells. Finally, we mapped transcriptomics modules associated with human diseases demonstrating the translational potential of our dataset. Overall, we provide a publicly available resource defining principles of transcriptomic regionalization of the colon during mucosal healing and a framework to develop and progress further hypotheses.
  •  
49.
  • Ratz, M., et al. (författare)
  • Clonal relations in the mouse brain revealed by single-cell and spatial transcriptomics
  • 2022
  • Ingår i: Nature Neuroscience. - : Springer Nature. - 1097-6256 .- 1546-1726. ; 25:3, s. 285-294
  • Tidskriftsartikel (refereegranskat)abstract
    • The mammalian brain contains many specialized cells that develop from a thin sheet of neuroepithelial progenitor cells. Single-cell transcriptomics revealed hundreds of molecularly diverse cell types in the nervous system, but the lineage relationships between mature cell types and progenitor cells are not well understood. Here we show in vivo barcoding of early progenitors to simultaneously profile cell phenotypes and clonal relations in the mouse brain using single-cell and spatial transcriptomics. By reconstructing thousands of clones, we discovered fate-restricted progenitor cells in the mouse hippocampal neuroepithelium and show that microglia are derived from few primitive myeloid precursors that massively expand to generate widely dispersed progeny. We combined spatial transcriptomics with clonal barcoding and disentangled migration patterns of clonally related cells in densely labeled tissue sections. Our approach enables high-throughput dense reconstruction of cell phenotypes and clonal relations at the single-cell and tissue level in individual animals and provides an integrated approach for understanding tissue architecture.
  •  
50.
  • Salmén, Fredrik, et al. (författare)
  • Multidimensional transcriptomics provides detailed information about immune cell distribution an identity in HER2+ breast tumors
  • 2018
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • The comprehensive analysis of tumor tissue heterogeneity is crucial for determining specific disease states and establishing suitable treatment regimes. Here, we analyze tumor tissue sections from ten patients diagnosed with HER2+ breast cancer. We obtain and analyze multidimensional, genome-wide transcriptomics data to resolve spatial immune cell distribution and identity within the tissue sections. Furthermore, we determine the extent of immune cell infiltration in different regions of the tumor tissue, including invasive cancer regions. We combine cross-sectioning and computational alignment to build three-dimensional images of the transcriptional landscape of the tumor and its microenvironment. The three-dimensional data clearly demonstrates the heterogeneous nature of tumor-immune interactions and reveal interpatient differences in immune cell infiltration patterns. Our study shows the potential for an improved stratification and description of the tumor-immune interplay, which is likely to be essential in treatment decisions.
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