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  1. Article ; Online: Single-Nucleus ATAC-seq for Mapping Chromatin Accessibility in Individual Cells of Murine Hearts.

    Yekelchyk, Michail / Li, Xiang / Guenther, Stefan / Braun, Thomas

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

    2024  Volume 2752, Page(s) 245–257

    Abstract: During the last decade a wide range of single-cell and single-nucleus next-generation sequencing techniques have been developed, which revolutionized detection of rare cell populations, enabling creation of comprehensive cell atlases of complex organs ... ...

    Abstract During the last decade a wide range of single-cell and single-nucleus next-generation sequencing techniques have been developed, which revolutionized detection of rare cell populations, enabling creation of comprehensive cell atlases of complex organs and tissues. State-of-the-art methods do not only allow classical transcriptomics of individual cells but also comprise a number of epigenetic approaches, including assessment of chromatin accessibility by single-nucleus Assay for Transposase Accessible Chromatin ATAC-seq (snATAC-seq). The snATAC-seq assay detects "open chromatin," a term for low nucleosome occupancy of genomic regions, which is a prerequisite for effective transcription factor binding. Information about open chromatin at the single-nucleus level helps to recognize epigenetic changes, sometimes before transcription of respective genes occurs. snATAC-seq detects cellular heterogeneity in otherwise still transcriptionally and/or morphologically homogeneous cell populations. Chromatin accessibility assays may be used to detect epigenetic changes in cardiac lineages during heart development, chromatin landscape changes during aging, and epigenetic alterations in heart diseases. Here, we provide an optimized protocol for snATAC-seq of murine hearts. We describe isolation of single nuclei from snap-frozen hearts, provide hints for preparation of libraries suitable for snATAC-seq next-generation sequencing (NGS) using the Chromium 10× platform, and give general recommendations for downstream analysis using conventional bioinformatic pipelines and packages. The protocol should serve as a beginner's guide to generate high-quality snATAC-seq datasets and to perform chromatin accessibility analysis of individual heart-derived cell nuclei.
    MeSH term(s) Animals ; Mice ; Chromatin/genetics ; Chromatin Immunoprecipitation Sequencing ; Heart ; Nucleosomes ; Cell Nucleus/genetics
    Chemical Substances Chromatin ; Nucleosomes
    Language English
    Publishing date 2024-01-09
    Publishing country United States
    Document type Journal Article
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-0716-3621-3_16
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Online ; Thesis: Deciphering cellular heterogeneity of cardiomyocytes and muscle stem cells during pathology and ageing

    Yekelchyk, Michail [Verfasser]

    2021  

    Author's details Michail Yekelchyk
    Keywords Biowissenschaften, Biologie ; Life Science, Biology
    Subject code sg570
    Language English
    Publisher Universitätsbibliothek
    Publishing place Gießen
    Document type Book ; Online ; Thesis
    Database Digital theses on the web

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  3. Article ; Online: Assay for Transposase-Accessible Chromatin Using Sequencing of Freshly Isolated Muscle Stem Cells.

    Yekelchyk, Michail / Guenther, Stefan / Braun, Thomas

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

    2023  Volume 2640, Page(s) 397–412

    Abstract: Actively transcribed genes harbor cis-regulatory modules with comparatively low nucleosome occupancy and few high-order structures (="open chromatin"), whereas non-transcribed genes are characterized by high nucleosome density and extensive interactions ... ...

    Abstract Actively transcribed genes harbor cis-regulatory modules with comparatively low nucleosome occupancy and few high-order structures (="open chromatin"), whereas non-transcribed genes are characterized by high nucleosome density and extensive interactions between nucleosomes (="closed chromatin"), preventing transcription factor binding. Knowledge about chromatin accessibility is crucial to understand gene regulatory networks determining cellular decisions. Several techniques are available to map chromatin accessibility, among which the Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) is one of the most popular. ATAC-seq is based on a straightforward and robust protocol but requires adjustments for different cell types. Here, we describe an optimized protocol for ATAC-seq of freshly isolated murine muscle stem cells. We provide details for the isolation of MuSC, tagmentation, library amplification, double-sided SPRI bead cleanup, and library quality assessment and give recommendations for sequencing parameters and downstream analysis. The protocol should facilitate generation of high-quality data sets of chromatin accessibility in MuSCs, even for newcomers to the field.
    MeSH term(s) Animals ; Mice ; Chromatin/genetics ; Nucleosomes ; Chromatin Immunoprecipitation Sequencing ; Transposases/metabolism ; High-Throughput Nucleotide Sequencing/methods ; Sequence Analysis, DNA/methods ; Stem Cells/metabolism ; Muscles/metabolism
    Chemical Substances Chromatin ; Nucleosomes ; Transposases (EC 2.7.7.-)
    Language English
    Publishing date 2023-03-30
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-0716-3036-5_27
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Mono- and multi-nucleated ventricular cardiomyocytes constitute a transcriptionally homogenous cell population.

    Yekelchyk, Michail / Guenther, Stefan / Preussner, Jens / Braun, Thomas

    Basic research in cardiology

    2019  Volume 114, Issue 5, Page(s) 36

    Abstract: Individual adult ventricular cardiomyocytes are either mono- or multi-nucleated and undergo morphological changes during cardiac hypertrophy. However, corresponding transcriptional signatures, reflecting potentially different functions or the ability for ...

    Abstract Individual adult ventricular cardiomyocytes are either mono- or multi-nucleated and undergo morphological changes during cardiac hypertrophy. However, corresponding transcriptional signatures, reflecting potentially different functions or the ability for cell-cycle entry, are not known. The aim of this study was to determine the transcriptional profile of mono- and multi-nucleated adult cardiomyocytes by single-cell RNA-sequencing (scRNA-seq) and to investigate heterogeneity among cardiomyocytes under baseline conditions and in pressure-induced cardiac hypertrophy. We developed an array-based approach for scRNA-seq of rod-shaped multi-nucleated cardiomyocytes from both healthy and hypertrophic hearts. Single-cell transcriptomes of mono- or multi-nucleated cardiomyocytes were highly similar, although a certain degree of variation was noted across both populations. Non-image-based quality control allowing inclusion of damaged cardiomyocytes generated artificial cell clusters demonstrating the need for strict exclusion criteria. In contrast, cardiomyocytes isolated from hypertrophic heart after transverse aortic constriction showed heterogeneous transcriptional signatures, characteristic for hypoxia-induced responses. Immunofluorescence analysis revealed an inverse correlation between HIF1α
    MeSH term(s) Animals ; Cardiomegaly/pathology ; Heart Ventricles/cytology ; Male ; Mice ; Mice, Inbred C57BL ; Myocytes, Cardiac/cytology ; Transcriptome
    Language English
    Publishing date 2019-08-09
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 189755-x
    ISSN 1435-1803 ; 0300-8428 ; 0175-9418
    ISSN (online) 1435-1803
    ISSN 0300-8428 ; 0175-9418
    DOI 10.1007/s00395-019-0744-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Cell competition in intratumoral and tumor microenvironment interactions.

    Parker, Taylor M / Gupta, Kartik / Palma, António M / Yekelchyk, Michail / Fisher, Paul B / Grossman, Steven R / Won, Kyoung Jae / Madan, Esha / Moreno, Eduardo / Gogna, Rajan

    The EMBO journal

    2021  Volume 40, Issue 17, Page(s) e107271

    Abstract: Tumors are complex cellular and acellular environments within which cancer clones are under continuous selection pressures. Cancer cells are in a permanent mode of interaction and competition with each other as well as with the immediate microenvironment. ...

    Abstract Tumors are complex cellular and acellular environments within which cancer clones are under continuous selection pressures. Cancer cells are in a permanent mode of interaction and competition with each other as well as with the immediate microenvironment. In the course of these competitive interactions, cells share information regarding their general state of fitness, with less-fit cells being typically eliminated via apoptosis at the hands of those cells with greater cellular fitness. Competitive interactions involving exchange of cell fitness information have implications for tumor growth, metastasis, and therapy outcomes. Recent research has highlighted sophisticated pathways such as Flower, Hippo, Myc, and p53 signaling, which are employed by cancer cells and the surrounding microenvironment cells to achieve their evolutionary goals by means of cell competition mechanisms. In this review, we discuss these recent findings and explain their importance and role in evolution, growth, and treatment of cancer. We further consider potential physiological conditions, such as hypoxia and chemotherapy, that can function as selective pressures under which cell competition mechanisms may evolve differently or synergistically to confer oncogenic advantages to cancer.
    MeSH term(s) Animals ; Cell Competition ; Humans ; Neoplasms/metabolism ; Neoplasms/pathology ; Signal Transduction ; Tumor Microenvironment
    Language English
    Publishing date 2021-08-09
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 586044-1
    ISSN 1460-2075 ; 0261-4189
    ISSN (online) 1460-2075
    ISSN 0261-4189
    DOI 10.15252/embj.2020107271
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Cell Competition Boosts Clonal Evolution and Hypoxic Selection in Cancer.

    Madan, Esha / Peixoto, Maria Leonor / Dimitrion, Peter / Eubank, Timothy D / Yekelchyk, Michail / Talukdar, Sarmistha / Fisher, Paul B / Mi, Qing-Sheng / Moreno, Eduardo / Gogna, Rajan

    Trends in cell biology

    2020  Volume 30, Issue 12, Page(s) 967–978

    Abstract: The comparison of fitness between cells leads to the elimination of less competent cells in the presence of more competent neighbors via cell competition (CC). This phenomenon has been linked with several cancer-related genes and thus may play an ... ...

    Abstract The comparison of fitness between cells leads to the elimination of less competent cells in the presence of more competent neighbors via cell competition (CC). This phenomenon has been linked with several cancer-related genes and thus may play an important role in cancer. Various processes are involved in the regulation of tumor initiation and growth, including tumor hypoxia, clonal stem cell selection, and immune cell response, all of which have been recently shown to have a potential connection with the mechanisms involved in CC. This review aims to unravel the relation between these processes and competitive cell interactions and how this affects disease progression.
    MeSH term(s) Animals ; Cell Competition ; Clonal Evolution ; Humans ; Lymph Nodes/pathology ; Stem Cells/metabolism ; Tumor Hypoxia ; Tumor Microenvironment
    Language English
    Publishing date 2020-11-04
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 30122-x
    ISSN 1879-3088 ; 0962-8924
    ISSN (online) 1879-3088
    ISSN 0962-8924
    DOI 10.1016/j.tcb.2020.10.002
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Single cell RNA-seq and ATAC-seq analysis of cardiac progenitor cell transition states and lineage settlement.

    Jia, Guangshuai / Preussner, Jens / Chen, Xi / Guenther, Stefan / Yuan, Xuejun / Yekelchyk, Michail / Kuenne, Carsten / Looso, Mario / Zhou, Yonggang / Teichmann, Sarah / Braun, Thomas

    Nature communications

    2018  Volume 9, Issue 1, Page(s) 4877

    Abstract: Formation and segregation of cell lineages forming the heart have been studied extensively but the underlying gene regulatory networks and epigenetic changes driving cell fate transitions during early cardiogenesis are still only partially understood. ... ...

    Abstract Formation and segregation of cell lineages forming the heart have been studied extensively but the underlying gene regulatory networks and epigenetic changes driving cell fate transitions during early cardiogenesis are still only partially understood. Here, we comprehensively characterize mouse cardiac progenitor cells (CPCs) marked by Nkx2-5 and Isl1 expression from E7.5 to E9.5 using single-cell RNA sequencing and transposase-accessible chromatin profiling (ATAC-seq). By leveraging on cell-to-cell transcriptome and chromatin accessibility heterogeneity, we identify different previously unknown cardiac subpopulations. Reconstruction of developmental trajectories reveal that multipotent Isl1
    MeSH term(s) Animals ; Body Patterning/genetics ; Cell Differentiation ; Cell Lineage/genetics ; Chromatin/chemistry ; Chromatin/metabolism ; Embryo, Mammalian ; Gene Expression Regulation, Developmental ; Gene Regulatory Networks ; Homeobox Protein Nkx-2.5/genetics ; Homeobox Protein Nkx-2.5/metabolism ; LIM-Homeodomain Proteins/genetics ; LIM-Homeodomain Proteins/metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Mouse Embryonic Stem Cells/cytology ; Mouse Embryonic Stem Cells/metabolism ; Myocytes, Cardiac/cytology ; Myocytes, Cardiac/metabolism ; Sequence Analysis, RNA ; Signal Transduction ; Single-Cell Analysis ; Transcription Factors/genetics ; Transcription Factors/metabolism ; Transcriptome
    Chemical Substances Chromatin ; Homeobox Protein Nkx-2.5 ; LIM-Homeodomain Proteins ; Nkx2-5 protein, mouse ; Transcription Factors ; insulin gene enhancer binding protein Isl-1
    Language English
    Publishing date 2018-11-19
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-018-07307-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Pleiotropic effects of laminar flow and statins depend on the Krüppel-like factor-induced lncRNA MANTIS.

    Leisegang, Matthias S / Bibli, Sofia-Iris / Günther, Stefan / Pflüger-Müller, Beatrice / Oo, James A / Höper, Cindy / Seredinski, Sandra / Yekelchyk, Michail / Schmitz-Rixen, Thomas / Schürmann, Christoph / Hu, Jiong / Looso, Mario / Sigala, Fragiska / Boon, Reinier A / Fleming, Ingrid / Brandes, Ralf P

    European heart journal

    2019  Volume 40, Issue 30, Page(s) 2523–2533

    Abstract: Aims: To assess the functional relevance and therapeutic potential of the pro-angiogenic long non-coding RNA MANTIS in vascular disease development.: Methods and results: RNA sequencing, CRISPR activation, overexpression, and RNAi demonstrated that ... ...

    Abstract Aims: To assess the functional relevance and therapeutic potential of the pro-angiogenic long non-coding RNA MANTIS in vascular disease development.
    Methods and results: RNA sequencing, CRISPR activation, overexpression, and RNAi demonstrated that MANTIS, especially its Alu-element, limits endothelial ICAM-1 expression in different types of endothelial cells. Loss of MANTIS increased endothelial monocyte adhesion in an ICAM-1-dependent manner. MANTIS reduced the binding of the SWI/SNF chromatin remodelling factor BRG1 at the ICAM-1 promoter. The expression of MANTIS was induced by laminar flow and HMG-CoA-reductase inhibitors (statins) through mechanisms involving epigenetic rearrangements and the transcription factors KLF2 and KLF4. Mutation of the KLF binding motifs in the MANTIS promoter blocked the flow-induced MANTIS expression. Importantly, the expression of MANTIS in human carotid artery endarterectomy material was lower compared with healthy vessels and this effect was prevented by statin therapy. Interestingly, the protective effects of statins were mediated in part through MANTIS, which was required to facilitate the atorvastatin-induced changes in endothelial gene expression. Moreover, the beneficial endothelial effects of statins in culture models (spheroid outgrowth, proliferation, telomerase activity, and vascular organ culture) were lost upon knockdown of MANTIS.
    Conclusion: MANTIS is tightly regulated by the transcription factors KLF2 and KLF4 and limits the ICAM-1 mediated monocyte adhesion to endothelial cells and thus potentially atherosclerosis development in humans. The beneficial effects of statin treatment and laminar flow are dependent on MANTIS.
    MeSH term(s) Angiogenesis Inducing Agents/metabolism ; Blood Flow Velocity/physiology ; Carotid Stenosis/metabolism ; Cell Adhesion/drug effects ; Cell Adhesion/physiology ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology ; Intercellular Adhesion Molecule-1/metabolism ; Kruppel-Like Transcription Factors/metabolism ; RNA, Long Noncoding/metabolism
    Chemical Substances Angiogenesis Inducing Agents ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; ICAM1 protein, human ; Kruppel-Like Transcription Factors ; RNA, Long Noncoding ; Intercellular Adhesion Molecule-1 (126547-89-5)
    Language English
    Publishing date 2019-06-20
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 603098-1
    ISSN 1522-9645 ; 0195-668X
    ISSN (online) 1522-9645
    ISSN 0195-668X
    DOI 10.1093/eurheartj/ehz393
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Single cell RNA-seq and ATAC-seq analysis of cardiac progenitor cell transition states and lineage settlement

    Guangshuai Jia / Jens Preussner / Xi Chen / Stefan Guenther / Xuejun Yuan / Michail Yekelchyk / Carsten Kuenne / Mario Looso / Yonggang Zhou / Sarah Teichmann / Thomas Braun

    Nature Communications, Vol 9, Iss 1, Pp 1-

    2018  Volume 17

    Abstract: Cardiac progenitor cells (CPCs) form cardiomyocytes, pericytes, smooth muscle and endothelial cells during embryonic development. Here, the authors characterize mouse CPCs marked by Nkx2.5 and Isl1 from E7.5 to E9.5 by single cell RNA-seq and ATAC-seq, ... ...

    Abstract Cardiac progenitor cells (CPCs) form cardiomyocytes, pericytes, smooth muscle and endothelial cells during embryonic development. Here, the authors characterize mouse CPCs marked by Nkx2.5 and Isl1 from E7.5 to E9.5 by single cell RNA-seq and ATAC-seq, showing fate transitions involve distinct open chromatin state.
    Keywords Science ; Q
    Language English
    Publishing date 2018-11-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Flower lose, a cell fitness marker, predicts COVID-19 prognosis.

    Yekelchyk, Michail / Madan, Esha / Wilhelm, Jochen / Short, Kirsty R / Palma, António M / Liao, Linbu / Camacho, Denise / Nkadori, Everlyne / Winters, Michael T / Rice, Emily S / Rolim, Inês / Cruz-Duarte, Raquel / Pelham, Christopher J / Nagane, Masaki / Gupta, Kartik / Chaudhary, Sahil / Braun, Thomas / Pillappa, Raghavendra / Parker, Mark S /
    Menter, Thomas / Matter, Matthias / Haslbauer, Jasmin Dionne / Tolnay, Markus / Galior, Kornelia D / Matkwoskyj, Kristina A / McGregor, Stephanie M / Muller, Laura K / Rakha, Emad A / Lopez-Beltran, Antonio / Drapkin, Ronny / Ackermann, Maximilian / Fisher, Paul B / Grossman, Steven R / Godwin, Andrew K / Kulasinghe, Arutha / Martinez, Ivan / Marsh, Clay B / Tang, Benjamin / Wicha, Max S / Won, Kyoung Jae / Tzankov, Alexandar / Moreno, Eduardo / Gogna, Rajan

    EMBO molecular medicine

    2021  Volume 13, Issue 11, Page(s) e13714

    Abstract: Risk stratification of COVID-19 patients is essential for pandemic management. Changes in the cell fitness marker, hFwe-Lose, can precede the host immune response to infection, potentially making such a biomarker an earlier triage tool. Here, we evaluate ...

    Abstract Risk stratification of COVID-19 patients is essential for pandemic management. Changes in the cell fitness marker, hFwe-Lose, can precede the host immune response to infection, potentially making such a biomarker an earlier triage tool. Here, we evaluate whether hFwe-Lose gene expression can outperform conventional methods in predicting outcomes (e.g., death and hospitalization) in COVID-19 patients. We performed a post-mortem examination of infected lung tissue in deceased COVID-19 patients to determine hFwe-Lose's biological role in acute lung injury. We then performed an observational study (n = 283) to evaluate whether hFwe-Lose expression (in nasopharyngeal samples) could accurately predict hospitalization or death in COVID-19 patients. In COVID-19 patients with acute lung injury, hFwe-Lose is highly expressed in the lower respiratory tract and is co-localized to areas of cell death. In patients presenting in the early phase of COVID-19 illness, hFwe-Lose expression accurately predicts subsequent hospitalization or death with positive predictive values of 87.8-100% and a negative predictive value of 64.1-93.2%. hFwe-Lose outperforms conventional inflammatory biomarkers and patient age and comorbidities, with an area under the receiver operating characteristic curve (AUROC) 0.93-0.97 in predicting hospitalization/death. Specifically, this is significantly higher than the prognostic value of combining biomarkers (serum ferritin, D-dimer, C-reactive protein, and neutrophil-lymphocyte ratio), patient age and comorbidities (AUROC of 0.67-0.92). The cell fitness marker, hFwe-Lose, accurately predicts outcomes in COVID-19 patients. This finding demonstrates how tissue fitness pathways dictate the response to infection and disease and their utility in managing the current COVID-19 pandemic.
    MeSH term(s) Biomarkers ; COVID-19 ; Flowers ; Humans ; Pandemics ; ROC Curve ; Retrospective Studies ; SARS-CoV-2 ; Severity of Illness Index
    Chemical Substances Biomarkers
    Language English
    Publishing date 2021-10-18
    Publishing country England
    Document type Journal Article ; Observational Study ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2467145-9
    ISSN 1757-4684 ; 1757-4676
    ISSN (online) 1757-4684
    ISSN 1757-4676
    DOI 10.15252/emmm.202013714
    Database MEDical Literature Analysis and Retrieval System OnLINE

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