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  1. Article ; Online: A Quantitative Framework for Evaluating Single-Cell Data Structure Preservation by Dimensionality Reduction Techniques

    Cody N. Heiser / Ken S. Lau

    Cell Reports, Vol 31, Iss 5, Pp - (2020)

    2020  

    Abstract: Summary: High-dimensional data, such as those generated by single-cell RNA sequencing (scRNA-seq), present challenges in interpretation and visualization. Numerical and computational methods for dimensionality reduction allow for low-dimensional ... ...

    Abstract Summary: High-dimensional data, such as those generated by single-cell RNA sequencing (scRNA-seq), present challenges in interpretation and visualization. Numerical and computational methods for dimensionality reduction allow for low-dimensional representation of genome-scale expression data for downstream clustering, trajectory reconstruction, and biological interpretation. However, a comprehensive and quantitative evaluation of the performance of these techniques has not been established. We present an unbiased framework that defines metrics of global and local structure preservation in dimensionality reduction transformations. Using discrete and continuous real-world and synthetic scRNA-seq datasets, we show how input cell distribution and method parameters are largely determinant of global, local, and organizational data structure preservation by 11 common dimensionality reduction methods.
    Keywords single-cell transcriptomics ; dimensionality reduction ; visualization ; single-cell analysis ; data analysis ; unsupervised learning ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2020-05-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: A contamination focused approach for optimizing the single-cell RNA-seq experiment

    Deronisha Arceneaux / Zhengyi Chen / Alan J. Simmons / Cody N. Heiser / Austin N. Southard-Smith / Michael J. Brenan / Yilin Yang / Bob Chen / Yanwen Xu / Eunyoung Choi / Joshua D. Campbell / Qi Liu / Ken S. Lau

    iScience, Vol 26, Iss 7, Pp 107242- (2023)

    2023  

    Abstract: Summary: Droplet-based single-cell RNA-seq (scRNA-seq) data are plagued by ambient contaminations caused by nucleic acid material released by dead and dying cells. This material is mixed into the buffer and is co-encapsulated with cells, leading to a ... ...

    Abstract Summary: Droplet-based single-cell RNA-seq (scRNA-seq) data are plagued by ambient contaminations caused by nucleic acid material released by dead and dying cells. This material is mixed into the buffer and is co-encapsulated with cells, leading to a lower signal-to-noise ratio. Although there exist computational methods to remove ambient contaminations post-hoc, the reliability of algorithms in generating high-quality data from low-quality sources remains uncertain. Here, we assess data quality before data filtering by a set of quantitative, contamination-based metrics that assess data quality more effectively than standard metrics. Through a series of controlled experiments, we report improvements that can minimize ambient contamination outside of tissue dissociation, via cell fixation, improved cell loading, microfluidic dilution, and nuclei versus cell preparation; many of these parameters are inaccessible on commercial platforms. We provide end-users with insights on factors that can guide their decision-making regarding optimizations that minimize ambient contamination, and metrics to assess data quality.
    Keywords Computational bioinformatics ; Transcriptomics ; Biology experimental methods ; Science ; Q
    Subject code 310
    Language English
    Publishing date 2023-07-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: SELENOP modifies sporadic colorectal carcinogenesis and WNT signaling activity through LRP5/6 interactions

    Jennifer M. Pilat / Rachel E. Brown / Zhengyi Chen / Nathaniel J. Berle / Adrian P. Othon / M. Kay Washington / Shruti A. Anant / Suguru Kurokawa / Victoria H. Ng / Joshua J. Thompson / Justin Jacobse / Jeremy A. Goettel / Ethan Lee / Yash A. Choksi / Ken S. Lau / Sarah P. Short / Christopher S. Williams

    The Journal of Clinical Investigation, Vol 133, Iss

    2023  Volume 13

    Abstract: Although selenium deficiency correlates with colorectal cancer (CRC) risk, the roles of the selenium-rich antioxidant selenoprotein P (SELENOP) in CRC remain unclear. In this study, we defined SELENOP’s contributions to sporadic CRC. In human single-cell ...

    Abstract Although selenium deficiency correlates with colorectal cancer (CRC) risk, the roles of the selenium-rich antioxidant selenoprotein P (SELENOP) in CRC remain unclear. In this study, we defined SELENOP’s contributions to sporadic CRC. In human single-cell cRNA-Seq (scRNA-Seq) data sets, we discovered that SELENOP expression rose as normal colon stem cells transformed into adenomas that progressed into carcinomas. We next examined the effects of Selenop KO in a mouse adenoma model that involved conditional, intestinal epithelium-specific deletion of the tumor suppressor adenomatous polyposis coli (Apc) and found that Selenop KO decreased colon tumor incidence and size. We mechanistically interrogated SELENOP-driven phenotypes in tumor organoids as well as in CRC and noncancer cell lines. Selenop-KO tumor organoids demonstrated defects in organoid formation and decreases in WNT target gene expression, which could be reversed by SELENOP restoration. Moreover, SELENOP increased canonical WNT signaling activity in noncancer and CRC cell lines. In defining the mechanism of action of SELENOP, we mapped protein-protein interactions between SELENOP and the WNT coreceptors low-density lipoprotein receptor–related proteins 5 and 6 (LRP5/6). Last, we confirmed that SELENOP-LRP5/6 interactions contributed to the effects of SELENOP on WNT activity. Overall, our results position SELENOP as a modulator of the WNT signaling pathway in sporadic CRC.
    Keywords Gastroenterology ; Medicine ; R
    Subject code 570
    Language English
    Publishing date 2023-07-01T00:00:00Z
    Publisher American Society for Clinical Investigation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: MTG16 regulates colonic epithelial differentiation, colitis, and tumorigenesis by repressing E protein transcription factors

    Rachel E. Brown / Justin Jacobse / Shruti A. Anant / Koral M. Blunt / Bob Chen / Paige N. Vega / Chase T. Jones / Jennifer M. Pilat / Frank Revetta / Aidan H. Gorby / Kristy R. Stengel / Yash A. Choksi / Kimmo Palin / M. Blanca Piazuelo / Mary Kay Washington / Ken S. Lau / Jeremy A. Goettel / Scott W. Hiebert / Sarah P. Short /
    Christopher S. Williams

    JCI Insight, Vol 7, Iss

    2022  Volume 10

    Abstract: Aberrant epithelial differentiation and regeneration contribute to colon pathologies, including inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Myeloid translocation gene 16 (MTG16, also known as CBFA2T3) is a transcriptional ... ...

    Abstract Aberrant epithelial differentiation and regeneration contribute to colon pathologies, including inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Myeloid translocation gene 16 (MTG16, also known as CBFA2T3) is a transcriptional corepressor expressed in the colonic epithelium. MTG16 deficiency in mice exacerbates colitis and increases tumor burden in CAC, though the underlying mechanisms remain unclear. Here, we identified MTG16 as a central mediator of epithelial differentiation, promoting goblet and restraining enteroendocrine cell development in homeostasis and enabling regeneration following dextran sulfate sodium–induced (DSS-induced) colitis. Transcriptomic analyses implicated increased Ephrussi box–binding transcription factor (E protein) activity in MTG16-deficient colon crypts. Using a mouse model with a point mutation that attenuates MTG16:E protein interactions (Mtg16P209T), we showed that MTG16 exerts control over colonic epithelial differentiation and regeneration by repressing E protein–mediated transcription. Mimicking murine colitis, MTG16 expression was increased in biopsies from patients with active IBD compared with unaffected controls. Finally, uncoupling MTG16:E protein interactions partially phenocopied the enhanced tumorigenicity of Mtg16–/– colon in the azoxymethane/DSS-induced model of CAC, indicating that MTG16 protects from tumorigenesis through additional mechanisms. Collectively, our results demonstrate that MTG16, via its repression of E protein targets, is a key regulator of cell fate decisions during colon homeostasis, colitis, and cancer.
    Keywords Cell biology ; Gastroenterology ; Medicine ; R
    Subject code 570
    Language English
    Publishing date 2022-05-01T00:00:00Z
    Publisher American Society for Clinical investigation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Interleukin-23 receptor signaling impairs the stability and function of colonic regulatory T cells

    Justin Jacobse / Rachel E. Brown / Jing Li / Jennifer M. Pilat / Ly Pham / Sarah P. Short / Christopher T. Peek / Andrea Rolong / M. Kay Washington / Ruben Martinez-Barricarte / Mariana X. Byndloss / Catherine Shelton / Janet G. Markle / Yvonne L. Latour / Margaret M. Allaman / James E. Cassat / Keith T. Wilson / Yash A. Choksi / Christopher S. Williams /
    Ken S. Lau / Charles R. Flynn / Jean-Laurent Casanova / Edmond H.H.M. Rings / Janneke N. Samsom / Jeremy A. Goettel

    Cell Reports, Vol 42, Iss 2, Pp 112128- (2023)

    2023  

    Abstract: Summary: The cytokine interleukin-23 (IL-23) is involved in the pathogenesis of inflammatory and autoimmune conditions including inflammatory bowel disease (IBD). IL23R is enriched in intestinal Tregs, yet whether IL-23 modulates intestinal Tregs remains ...

    Abstract Summary: The cytokine interleukin-23 (IL-23) is involved in the pathogenesis of inflammatory and autoimmune conditions including inflammatory bowel disease (IBD). IL23R is enriched in intestinal Tregs, yet whether IL-23 modulates intestinal Tregs remains unknown. Here, investigating IL-23R signaling in Tregs specifically, we show that colonic Tregs highly express Il23r compared with Tregs from other compartments and their frequency is reduced upon IL-23 administration and impairs Treg suppressive function. Similarly, colonic Treg frequency is increased in mice lacking Il23r specifically in Tregs and exhibits a competitive advantage over IL-23R-sufficient Tregs during inflammation. Finally, IL-23 antagonizes liver X receptor pathway, cellular cholesterol transporter Abca1, and increases Treg apoptosis. Our results show that IL-23R signaling regulates intestinal Tregs by increasing cell turnover, antagonizing suppression, and decreasing cholesterol efflux. These results suggest that IL-23 negatively regulates Tregs in the intestine with potential implications for promoting chronic inflammation in patients with IBD.
    Keywords CP: Immunology ; Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2023-02-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Clinically adaptable polymer enables simultaneous spatial analysis of colonic tissues and biofilms

    Mary C. Macedonia / Julia L. Drewes / Nicholas O. Markham / Alan J. Simmons / Joseph T. Roland / Paige N. Vega / Cherie’ R. Scurrah / Robert J. Coffey / Martha J. Shrubsole / Cynthia L. Sears / Ken S. Lau

    npj Biofilms and Microbiomes, Vol 6, Iss 1, Pp 1-

    2020  Volume 10

    Abstract: Abstract Microbial influences on host cells depend upon the identities of the microbes, their spatial localization, and the responses they invoke on specific host cell populations. Multimodal analyses of both microbes and host cells in a spatially ... ...

    Abstract Abstract Microbial influences on host cells depend upon the identities of the microbes, their spatial localization, and the responses they invoke on specific host cell populations. Multimodal analyses of both microbes and host cells in a spatially resolved fashion would enable studies into these complex interactions in native tissue environments, potentially in clinical specimens. While techniques to preserve each of the microbial and host cell compartments have been used to examine tissues and microbes separately, we endeavored to develop approaches to simultaneously analyze both compartments. Herein, we established an original method for mucus preservation using Poloxamer 407 (also known as Pluronic F-127), a thermoreversible polymer with mucus-adhesive characteristics. We demonstrate that this approach can preserve spatially-defined compartments of the mucus bi-layer in the colon and the bacterial communities within, compared with their marked absence when tissues were processed with traditional formalin-fixed paraffin-embedded (FFPE) pipelines. Additionally, antigens for antibody staining of host cells were preserved and signal intensity for 16S rRNA fluorescence in situ hybridization (FISH) was enhanced in poloxamer-fixed samples. This in turn enabled us to integrate multimodal analysis using a modified multiplex immunofluorescence (MxIF) protocol. Importantly, we have formulated Poloxamer 407 to polymerize and cross-link at room temperature for use in clinical workflows. These results suggest that the fixative formulation of Poloxamer 407 can be integrated into biospecimen collection pipelines for simultaneous analysis of microbes and host cells.
    Keywords Microbial ecology ; QR100-130
    Language English
    Publishing date 2020-09-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Quantitative assessment of cell population diversity in single-cell landscapes.

    Qi Liu / Charles A Herring / Quanhu Sheng / Jie Ping / Alan J Simmons / Bob Chen / Amrita Banerjee / Wei Li / Guoqiang Gu / Robert J Coffey / Yu Shyr / Ken S Lau

    PLoS Biology, Vol 16, Iss 10, p e

    2018  Volume 2006687

    Abstract: Single-cell RNA sequencing (scRNA-seq) has become a powerful tool for the systematic investigation of cellular diversity. As a number of computational tools have been developed to identify and visualize cell populations within a single scRNA-seq dataset, ...

    Abstract Single-cell RNA sequencing (scRNA-seq) has become a powerful tool for the systematic investigation of cellular diversity. As a number of computational tools have been developed to identify and visualize cell populations within a single scRNA-seq dataset, there is a need for methods to quantitatively and statistically define proportional shifts in cell population structures across datasets, such as expansion or shrinkage or emergence or disappearance of cell populations. Here we present sc-UniFrac, a framework to statistically quantify compositional diversity in cell populations between single-cell transcriptome landscapes. sc-UniFrac enables sensitive and robust quantification in simulated and experimental datasets in terms of both population identity and quantity. We have demonstrated the utility of sc-UniFrac in multiple applications, including assessment of biological and technical replicates, classification of tissue phenotypes and regional specification, identification and definition of altered cell infiltrates in tumorigenesis, and benchmarking batch-correction tools. sc-UniFrac provides a framework for quantifying diversity or alterations in cell populations across conditions and has broad utility for gaining insight into tissue-level perturbations at the single-cell resolution.
    Keywords Biology (General) ; QH301-705.5
    Subject code 612
    Language English
    Publishing date 2018-10-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Heterogeneity and dynamics of active Kras-induced dysplastic lineages from mouse corpus stomach

    Jimin Min / Paige N. Vega / Amy C. Engevik / Janice A. Williams / Qing Yang / Loraine M. Patterson / Alan J. Simmons / R. Jarrett Bliton / Joshua W. Betts / Ken S. Lau / Scott T. Magness / James R. Goldenring / Eunyoung Choi

    Nature Communications, Vol 10, Iss 1, Pp 1-

    2019  Volume 16

    Abstract: How a precancerous form (dysplasia) becomes gastric cancer is unclear. Here, the authors assess the role of Kras activation in heterogenous dysplastic cells in murine stomach corpus organoids, identifying two dysplastic stem cell populations and show ... ...

    Abstract How a precancerous form (dysplasia) becomes gastric cancer is unclear. Here, the authors assess the role of Kras activation in heterogenous dysplastic cells in murine stomach corpus organoids, identifying two dysplastic stem cell populations and show that MEK inhibition causes alterations in cell behavior.
    Keywords Science ; Q
    Language English
    Publishing date 2019-12-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Heterogeneity and dynamics of active Kras-induced dysplastic lineages from mouse corpus stomach

    Jimin Min / Paige N. Vega / Amy C. Engevik / Janice A. Williams / Qing Yang / Loraine M. Patterson / Alan J. Simmons / R. Jarrett Bliton / Joshua W. Betts / Ken S. Lau / Scott T. Magness / James R. Goldenring / Eunyoung Choi

    Nature Communications, Vol 10, Iss 1, Pp 1-

    2019  Volume 16

    Abstract: How a precancerous form (dysplasia) becomes gastric cancer is unclear. Here, the authors assess the role of Kras activation in heterogenous dysplastic cells in murine stomach corpus organoids, identifying two dysplastic stem cell populations and show ... ...

    Abstract How a precancerous form (dysplasia) becomes gastric cancer is unclear. Here, the authors assess the role of Kras activation in heterogenous dysplastic cells in murine stomach corpus organoids, identifying two dysplastic stem cell populations and show that MEK inhibition causes alterations in cell behavior.
    Keywords Science ; Q
    Language English
    Publishing date 2019-12-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Multi-scale in vivo systems analysis reveals the influence of immune cells on TNF-α-induced apoptosis in the intestinal epithelium.

    Ken S Lau / Virna Cortez-Retamozo / Sarah R Philips / Mikael J Pittet / Douglas A Lauffenburger / Kevin M Haigis

    PLoS Biology, Vol 10, Iss 9, p e

    2012  Volume 1001393

    Abstract: Intestinal epithelial cells exist within a complex environment that affects how they interpret and respond to stimuli. We have applied a multi-scale in vivo systems approach to understand how intestinal immune cells communicate with epithelial cells to ... ...

    Abstract Intestinal epithelial cells exist within a complex environment that affects how they interpret and respond to stimuli. We have applied a multi-scale in vivo systems approach to understand how intestinal immune cells communicate with epithelial cells to regulate responses to inflammatory signals. Multivariate modeling analysis of a large dataset composed of phospho-signals, cytokines, and immune cell populations within the intestine revealed an intimate relationship between immune cells and the epithelial response to TNF-α. Ablation of lymphocytes in the intestine prompted a decrease in the expression of MCP-1, which in turn increased the steady state number of intestinal plasmacytoid dendritic cells (pDCs). This change in the immune compartment affected the intestinal cytokine milieu and subsequent epithelial cell signaling network, with cells becoming hypersensitive to TNF-α-induced apoptosis in a way that could be predicted by mathematical modeling. In summary, we have uncovered a novel cellular network that regulates the response of intestinal epithelial cells to inflammatory stimuli in an in vivo setting.
    Keywords Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2012-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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