LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 50

Search options

  1. Article ; Online: Unbiased image segmentation assessment toolkit for quantitative differentiation of state-of-the-art algorithms and pipelines.

    Goyal, Vishakha / Schaub, Nick J / Voss, Ty C / Hotaling, Nathan A

    BMC bioinformatics

    2023  Volume 24, Issue 1, Page(s) 388

    Abstract: Background: Image segmentation pipelines are commonly used in microscopy to identify cellular compartments like nucleus and cytoplasm, but there are few standards for comparing segmentation accuracy across pipelines. The process of selecting a ... ...

    Abstract Background: Image segmentation pipelines are commonly used in microscopy to identify cellular compartments like nucleus and cytoplasm, but there are few standards for comparing segmentation accuracy across pipelines. The process of selecting a segmentation assessment pipeline can seem daunting to researchers due to the number and variety of metrics available for evaluating segmentation quality.
    Results: Here we present automated pipelines to obtain a comprehensive set of 69 metrics to evaluate segmented data and propose a selection methodology for models based on quantitative analysis, dimension reduction or unsupervised classification techniques and informed selection criteria.
    Conclusion: We show that the metrics used here can often be reduced to a small number of metrics that give a more complete understanding of segmentation accuracy, with different groups of metrics providing sensitivity to different types of segmentation error. These tools are delivered as easy to use python libraries, command line tools, Common Workflow Language Tools, and as Web Image Processing Pipeline interactive plugins to ensure a wide range of users can access and use them. We also present how our evaluation methods can be used to observe the changes in segmentations across modern machine learning/deep learning workflows and use cases.
    MeSH term(s) Image Processing, Computer-Assisted/methods ; Algorithms ; Microscopy ; Machine Learning ; Cytoplasm
    Language English
    Publishing date 2023-10-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 2041484-5
    ISSN 1471-2105 ; 1471-2105
    ISSN (online) 1471-2105
    ISSN 1471-2105
    DOI 10.1186/s12859-023-05486-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Dynamic regulation of transcriptional states by chromatin and transcription factors.

    Voss, Ty C / Hager, Gordon L

    Nature reviews. Genetics

    2013  Volume 15, Issue 2, Page(s) 69–81

    Abstract: The interaction of regulatory proteins with the complex nucleoprotein structures that are found in mammalian cells involves chromatin reorganization at multiple levels. Mechanisms that support these transitions are complex on many timescales, which range ...

    Abstract The interaction of regulatory proteins with the complex nucleoprotein structures that are found in mammalian cells involves chromatin reorganization at multiple levels. Mechanisms that support these transitions are complex on many timescales, which range from milliseconds to minutes or hours. In this Review, we discuss emerging concepts regarding the function of regulatory elements in living cells. We also explore the involvement of these dynamic and stochastic processes in the evolution of fluctuating transcriptional activity states that are now commonly reported in eukaryotic systems.
    MeSH term(s) Animals ; Chromatin/genetics ; Chromatin/metabolism ; Chromatin Assembly and Disassembly/genetics ; Gene Expression Regulation ; Humans ; Models, Genetic ; Nucleosomes/genetics ; Nucleosomes/metabolism ; Protein Binding ; Transcription Factors/metabolism ; Transcription, Genetic/genetics
    Chemical Substances Chromatin ; Nucleosomes ; Transcription Factors
    Language English
    Publishing date 2013-12-17
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 2035157-4
    ISSN 1471-0064 ; 1471-0056
    ISSN (online) 1471-0064
    ISSN 1471-0056
    DOI 10.1038/nrg3623
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article: Nonspecific membrane bilayer perturbations by ivermectin underlie SARS-CoV-2

    Eastman, Richard T / Rusinova, Radda / Herold, Karl F / Huang, Xi-Ping / Dranchak, Patricia / Voss, Ty C / Rana, Sandeep / Shrimp, Jonathan H / White, Alex D / Hemmings, Hugh C / Roth, Bryan L / Inglese, James / Andersen, Olaf S / Dahlin, Jayme L

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Since it was proposed as a potential host-directed antiviral agent for SARS-CoV-2, the antiparasitic drug ivermectin has been investigated thoroughly in clinical trials, which have provided insufficient support for its clinical efficacy. To examine the ... ...

    Abstract Since it was proposed as a potential host-directed antiviral agent for SARS-CoV-2, the antiparasitic drug ivermectin has been investigated thoroughly in clinical trials, which have provided insufficient support for its clinical efficacy. To examine the potential for ivermectin to be repurposed as an antiviral agent, we therefore undertook a series of preclinical studies. Consistent with early reports, ivermectin decreased SARS-CoV-2 viral burden in
    Language English
    Publishing date 2023-10-24
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.10.23.563088
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Stress-free cell aggregation by using the CEPT cocktail enhances embryoid body and organoid fitness.

    Ryu, Seungmi / Weber, Claire / Chu, Pei-Hsuan / Ernest, Ben / Jovanovic, Vukasin M / Deng, Tao / Slamecka, Jaroslav / Hong, Hyenjong / Jethmalani, Yogita / Baskir, Hannah M / Inman, Jason / Braisted, John / Hirst, Marissa B / Simeonov, Anton / Voss, Ty C / Tristan, Carlos A / Singeç, Ilyas

    Biofabrication

    2023  Volume 16, Issue 1

    Abstract: Embryoid bodies (EBs) and self-organizing organoids derived from human pluripotent stem cells (hPSCs) recapitulate tissue development in a dish and hold great promise for disease modeling and drug development. However, current protocols are hampered by ... ...

    Abstract Embryoid bodies (EBs) and self-organizing organoids derived from human pluripotent stem cells (hPSCs) recapitulate tissue development in a dish and hold great promise for disease modeling and drug development. However, current protocols are hampered by cellular stress and apoptosis during cell aggregation, resulting in variability and impaired cell differentiation. Here, we demonstrate that EBs and various organoid models (e.g., brain, gut, kidney) can be optimized by using the small molecule cocktail named CEPT (chroman 1, emricasan, polyamines, trans-ISRIB), a polypharmacological approach that ensures cytoprotection and cell survival. Application of CEPT for just 24 h during cell aggregation has long-lasting consequences affecting morphogenesis, gene expression, cellular differentiation, and organoid function. Various qualification methods confirmed that CEPT treatment enhanced experimental reproducibility and consistently improved EB and organoid fitness as compared to the widely used ROCK inhibitor Y-27632. Collectively, we discovered that stress-free cell aggregation and superior cell survival in the presence of CEPT are critical quality control determinants that establish a robust foundation for bioengineering complex tissue and organ models.
    MeSH term(s) Humans ; Embryoid Bodies/metabolism ; Reproducibility of Results ; Organoids ; Pluripotent Stem Cells ; Cell Differentiation
    Language English
    Publishing date 2023-12-11
    Publishing country England
    Document type Journal Article
    ZDB-ID 2500944-8
    ISSN 1758-5090 ; 1758-5082
    ISSN (online) 1758-5090
    ISSN 1758-5082
    DOI 10.1088/1758-5090/ad0d13
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Efficient and safe single-cell cloning of human pluripotent stem cells using the CEPT cocktail.

    Tristan, Carlos A / Hong, Hyenjong / Jethmalani, Yogita / Chen, Yu / Weber, Claire / Chu, Pei-Hsuan / Ryu, Seungmi / Jovanovic, Vukasin M / Hur, Inae / Voss, Ty C / Simeonov, Anton / Singeç, Ilyas

    Nature protocols

    2022  Volume 18, Issue 1, Page(s) 58–80

    Abstract: Human pluripotent stem cells (hPSCs) are inherently sensitive cells. Single-cell dissociation and the establishment of clonal cell lines have been long-standing challenges. This inefficiency of cell cloning represents a major obstacle for the ... ...

    Abstract Human pluripotent stem cells (hPSCs) are inherently sensitive cells. Single-cell dissociation and the establishment of clonal cell lines have been long-standing challenges. This inefficiency of cell cloning represents a major obstacle for the standardization and streamlining of gene editing in induced pluripotent stem cells for basic and translational research. Here we describe a chemically defined protocol for robust single-cell cloning using microfluidics-based cell sorting in combination with the CEPT small-molecule cocktail. This advanced strategy promotes the viability and cell fitness of self-renewing stem cells. The use of low-pressure microfluidic cell dispensing ensures gentle and rapid dispensing of single cells into 96- and 384-well plates, while the fast-acting CEPT cocktail minimizes cellular stress and maintains cell structure and function immediately after cell dissociation. The protocol also facilitates clone picking and produces genetically stable clonal cell lines from hPSCs in a safe and cost-efficient fashion. Depending on the proliferation rate of the clone derived from a single cell, this protocol can be completed in 7-14 d and requires experience with aseptic cell culture techniques. Altogether, the relative ease, scalability and robustness of this workflow should boost gene editing in hPSCs and leverage a wide range of applications, including cell line development (e.g., reporter and isogenic cell lines), disease modeling and applications in regenerative medicine.
    MeSH term(s) Humans ; Pluripotent Stem Cells ; Induced Pluripotent Stem Cells ; Cell Culture Techniques/methods ; Cell Line ; Cell Differentiation ; Cloning, Molecular
    Language English
    Publishing date 2022-10-19
    Publishing country England
    Document type Journal Article ; Review ; Research Support, N.I.H., Intramural ; Research Support, N.I.H., Extramural
    ZDB-ID 2244966-8
    ISSN 1750-2799 ; 1754-2189
    ISSN (online) 1750-2799
    ISSN 1754-2189
    DOI 10.1038/s41596-022-00753-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Identification by high-throughput imaging of the histone methyltransferase EHMT2 as an epigenetic regulator of VEGFA alternative splicing.

    Salton, Maayan / Voss, Ty C / Misteli, Tom

    Nucleic acids research

    2014  Volume 42, Issue 22, Page(s) 13662–13673

    Abstract: Recent evidence points to a role of chromatin in regulation of alternative pre-mRNA splicing (AS). In order to identify novel chromatin regulators of AS, we screened an RNAi library of chromatin proteins using a cell-based high-throughput in vivo assay. ... ...

    Abstract Recent evidence points to a role of chromatin in regulation of alternative pre-mRNA splicing (AS). In order to identify novel chromatin regulators of AS, we screened an RNAi library of chromatin proteins using a cell-based high-throughput in vivo assay. We identified a set of chromatin proteins that regulate AS. Using simultaneous genome-wide expression and AS analysis, we demonstrate distinct and non-overlapping functions of these chromatin modifiers on transcription and AS. Detailed mechanistic characterization of one dual function chromatin modifier, the H3K9 methyltransferase EHMT2 (G9a), identified VEGFA as a major chromatin-mediated AS target. Silencing of EHMT2, or its heterodimer partner EHMT1, affects AS by promoting exclusion of VEGFA exon 6a, but does not alter total VEGFA mRNA levels. The epigenetic regulatory mechanism of AS by EHMT2 involves an adaptor system consisting of the chromatin modulator HP1γ, which binds methylated H3K9 and recruits splicing regulator SRSF1. The epigenetic regulation of VEGFA is physiologically relevant since EHMT2 is transcriptionally induced in response to hypoxia and triggers concomitant changes in AS of VEGFA. These results characterize a novel epigenetic regulatory mechanism of AS and they demonstrate separate roles of epigenetic modifiers in transcription and alternative splicing.
    MeSH term(s) Alternative Splicing ; Cell Hypoxia ; Cell Line, Tumor ; Chromatin/metabolism ; Chromosomal Proteins, Non-Histone/metabolism ; Epigenesis, Genetic ; HEK293 Cells ; Histocompatibility Antigens/physiology ; Histone-Lysine N-Methyltransferase/physiology ; Humans ; MCF-7 Cells ; Microscopy, Fluorescence ; Nuclear Proteins/metabolism ; RNA Interference ; RNA-Binding Proteins/metabolism ; Serine-Arginine Splicing Factors ; Vascular Endothelial Growth Factor A/genetics ; Vascular Endothelial Growth Factor A/metabolism
    Chemical Substances CBX3 protein, human ; Chromatin ; Chromosomal Proteins, Non-Histone ; Histocompatibility Antigens ; Nuclear Proteins ; RNA-Binding Proteins ; VEGFA protein, human ; Vascular Endothelial Growth Factor A ; Serine-Arginine Splicing Factors (170974-22-8) ; EHMT2 protein, human (EC 2.1.1.43) ; Histone-Lysine N-Methyltransferase (EC 2.1.1.43)
    Language English
    Publishing date 2014-12-16
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Intramural
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gku1226
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: High-throughput fluorescence-based screen to identify factors involved in nuclear receptor recruitment to response elements.

    Miranda, Tina B / Voss, Ty C / Hager, Gordon L

    Methods in molecular biology (Clifton, N.J.)

    2013  Volume 1042, Page(s) 3–12

    Abstract: The glucocorticoid receptor is an inducible transcription factor which plays important roles in many -physiological processes. Upon activation, GR interacts with regulatory elements and modulates the expression of genes. Although GR is widely expressed ... ...

    Abstract The glucocorticoid receptor is an inducible transcription factor which plays important roles in many -physiological processes. Upon activation, GR interacts with regulatory elements and modulates the expression of genes. Although GR is widely expressed in multiple tissues, its binding sites within chromatin and the genes it regulates are tissue specific. Many accessory proteins and cofactors are thought to play a role in dictating GR's function; however, mechanisms involved in targeting GR to specific sites in the genome are not well understood. Here we describe a high-throughput fluorescence-based method to identify factors involved in GR loading at response elements. This screen utilizes a genetically engineered cell line that contains 200 repeats of a glucocorticoid response promoter and expresses GFP-tagged GR. Upon treatment with corticosteroids, GFP-GR forms a steady-state distribution at the promoter array, and its concentration at this focal point can be quantitatively determined. This system provides a novel approach to identify activities important for GR loading at its response element using siRNA libraries to target factors that enhance or inhibit receptor localization.
    MeSH term(s) Adrenal Cortex Hormones/antagonists & inhibitors ; Adrenal Cortex Hormones/metabolism ; Animals ; Binding Sites ; Cell Line ; Chromatin/metabolism ; Dexamethasone/pharmacology ; Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)/genetics ; Green Fluorescent Proteins/genetics ; High-Throughput Screening Assays/methods ; Mice ; Mifepristone/pharmacology ; Promoter Regions, Genetic ; RNA Interference ; RNA, Small Interfering ; Receptors, Glucocorticoid/metabolism ; Response Elements/genetics
    Chemical Substances Adrenal Cortex Hormones ; Chromatin ; RNA, Small Interfering ; Receptors, Glucocorticoid ; Green Fluorescent Proteins (147336-22-9) ; Mifepristone (320T6RNW1F) ; Dexamethasone (7S5I7G3JQL) ; Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) (EC 1.2.1.12)
    Language English
    Publishing date 2013-08-25
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, N.I.H., Intramural
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-62703-526-2_1
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: A defined roadmap of radial glia and astrocyte differentiation from human pluripotent stem cells.

    Jovanovic, Vukasin M / Weber, Claire / Slamecka, Jaroslav / Ryu, Seungmi / Chu, Pei-Hsuan / Sen, Chaitali / Inman, Jason / De Sousa, Juliana Ferreira / Barnaeva, Elena / Hirst, Marissa / Galbraith, David / Ormanoglu, Pinar / Jethmalani, Yogita / Mercado, Jennifer Colon / Michael, Sam / Ward, Michael E / Simeonov, Anton / Voss, Ty C / Tristan, Carlos A /
    Singeç, Ilyas

    Stem cell reports

    2023  Volume 18, Issue 8, Page(s) 1701–1720

    Abstract: Human gliogenesis remains poorly understood, and derivation of astrocytes from human pluripotent stem cells (hPSCs) is inefficient and cumbersome. Here, we report controlled glial differentiation from hPSCs that bypasses neurogenesis, which otherwise ... ...

    Abstract Human gliogenesis remains poorly understood, and derivation of astrocytes from human pluripotent stem cells (hPSCs) is inefficient and cumbersome. Here, we report controlled glial differentiation from hPSCs that bypasses neurogenesis, which otherwise precedes astrogliogenesis during brain development and in vitro differentiation. hPSCs were first differentiated into radial glial cells (RGCs) resembling resident RGCs of the fetal telencephalon, and modulation of specific cell signaling pathways resulted in direct and stepwise induction of key astroglial markers (NFIA, NFIB, SOX9, CD44, S100B, glial fibrillary acidic protein [GFAP]). Transcriptomic and genome-wide epigenetic mapping and single-cell analysis confirmed RGC-to-astrocyte differentiation, obviating neurogenesis and the gliogenic switch. Detailed molecular and cellular characterization experiments uncovered new mechanisms and markers for human RGCs and astrocytes. In summary, establishment of a glia-exclusive neural lineage progression model serves as a unique serum-free platform of manufacturing large numbers of RGCs and astrocytes for neuroscience, disease modeling (e.g., Alexander disease), and regenerative medicine.
    MeSH term(s) Humans ; Astrocytes/metabolism ; Ependymoglial Cells/metabolism ; Pluripotent Stem Cells/metabolism ; Neurogenesis ; Cell Differentiation ; Glial Fibrillary Acidic Protein/metabolism
    Chemical Substances Glial Fibrillary Acidic Protein
    Language English
    Publishing date 2023-07-13
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, N.I.H., Intramural
    ZDB-ID 2720528-9
    ISSN 2213-6711 ; 2213-6711
    ISSN (online) 2213-6711
    ISSN 2213-6711
    DOI 10.1016/j.stemcr.2023.06.007
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Cell cycle staging of individual cells by fluorescence microscopy.

    Roukos, Vassilis / Pegoraro, Gianluca / Voss, Ty C / Misteli, Tom

    Nature protocols

    2015  Volume 10, Issue 2, Page(s) 334–348

    Abstract: Progression through the cell cycle is one of the most fundamental features of cells. Studies of the cell cycle have traditionally relied on the analysis of populations, and they often require specific markers or the use of genetically modified systems, ... ...

    Abstract Progression through the cell cycle is one of the most fundamental features of cells. Studies of the cell cycle have traditionally relied on the analysis of populations, and they often require specific markers or the use of genetically modified systems, making it difficult to determine the cell cycle stage of individual, unperturbed cells. We describe a protocol, suitable for use in high-resolution imaging approaches, for determining cell cycle staging of individual cells by measuring their DNA content by fluorescence microscopy. The approach is based on the accurate quantification by image analysis of the integrated nuclear intensity of cells stained with a DNA dye, and it can be used in combination with several histochemical methods. We describe and provide the algorithms for two automated image analysis pipelines and the derivation of cell cycle profiles with both commercial and open-source software. This 1-2-d protocol is applicable to adherent cells, and it is adaptable for use with several DNA dyes.
    MeSH term(s) Algorithms ; Animals ; Cell Cycle ; Cell Line ; Fluorescent Dyes ; Humans ; Image Processing, Computer-Assisted/methods ; Indoles/chemistry ; Mice ; Microscopy, Fluorescence/methods ; Single-Cell Analysis/methods ; Software
    Chemical Substances Fluorescent Dyes ; Indoles ; DAPI (47165-04-8)
    Language English
    Publishing date 2015-01-29
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Intramural
    ZDB-ID 2244966-8
    ISSN 1750-2799 ; 1754-2189
    ISSN (online) 1750-2799
    ISSN 1754-2189
    DOI 10.1038/nprot.2015.016
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Scalable generation of sensory neurons from human pluripotent stem cells.

    Deng, Tao / Jovanovic, Vukasin M / Tristan, Carlos A / Weber, Claire / Chu, Pei-Hsuan / Inman, Jason / Ryu, Seungmi / Jethmalani, Yogita / Ferreira de Sousa, Juliana / Ormanoglu, Pinar / Twumasi, Prisca / Sen, Chaitali / Shim, Jaehoon / Jayakar, Selwyn / Bear Zhang, Han-Xiong / Jo, Sooyeon / Yu, Weifeng / Voss, Ty C / Simeonov, Anton /
    Bean, Bruce P / Woolf, Clifford J / Singeç, Ilyas

    Stem cell reports

    2023  Volume 18, Issue 4, Page(s) 1030–1047

    Abstract: Development of new non-addictive analgesics requires advanced strategies to differentiate human pluripotent stem cells (hPSCs) into relevant cell types. Following principles of developmental biology and translational applicability, here we developed an ... ...

    Abstract Development of new non-addictive analgesics requires advanced strategies to differentiate human pluripotent stem cells (hPSCs) into relevant cell types. Following principles of developmental biology and translational applicability, here we developed an efficient stepwise differentiation method for peptidergic and non-peptidergic nociceptors. By modulating specific cell signaling pathways, hPSCs were first converted into SOX10
    MeSH term(s) Humans ; Neurons/metabolism ; Nociceptors ; Cell Differentiation ; Signal Transduction ; Pluripotent Stem Cells ; Ganglia, Spinal/metabolism ; Sensory Receptor Cells
    Language English
    Publishing date 2023-04-11
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2720528-9
    ISSN 2213-6711 ; 2213-6711
    ISSN (online) 2213-6711
    ISSN 2213-6711
    DOI 10.1016/j.stemcr.2023.03.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top