scholarly journals Cell-type specific and combinatorial usage of diverse transcription factors revealed by genome-wide binding studies in multiple human cells

2011 ◽  
Vol 22 (1) ◽  
pp. 9-24 ◽  
Author(s):  
B.-K. Lee ◽  
A. A. Bhinge ◽  
A. Battenhouse ◽  
R. M. McDaniell ◽  
Z. Liu ◽  
...  
Blood ◽  
2021 ◽  
Author(s):  
Bon Q Trinh ◽  
Simone Ummarino ◽  
Yanzhou Zhang ◽  
Alexander K Ebralidze ◽  
Mahmoud A Bassal ◽  
...  

The mechanism underlying cell type-specific gene induction conferred by ubiquitous transcription factors as well as disruptions caused by their chimeric derivatives in leukemia is not well understood. Here we investigate whether RNAs coordinate with transcription factors to drive myeloid gene transcription. In an integrated genome-wide approach surveying for gene loci exhibiting concurrent RNA- and DNA-interactions with the broadly expressed transcription factor RUNX1, we identified the long noncoding RNA LOUP. This myeloid-specific and polyadenylated lncRNA induces myeloid differentiation and inhibits cell growth, acting as a transcriptional inducer of the myeloid master regulator PU.1. Mechanistically, LOUP recruits RUNX1 to both the PU.1 enhancer and the promoter, leading to the formation of an active chromatin loop. In t(8;21) acute myeloid leukemia, wherein RUNX1 is fused to ETO, the resulting oncogenic fusion protein RUNX1-ETO limits chromatin accessibility at the LOUP locus, causing inhibition of LOUP and PU.1 expression. These findings highlight the important role of the interplay between cell type-specific RNAs and transcription factors as well as their oncogenic derivatives in modulating lineage-gene activation and raise the possibility that RNA regulators of transcription factors represent alternative targets for therapeutic development.


2018 ◽  
Author(s):  
Bryce van de Geijn ◽  
Hilary Finucane ◽  
Steven Gazal ◽  
Farhad Hormozdiari ◽  
Tiffany Amariuta ◽  
...  

AbstractIt is widely known that regulatory variation plays a major role in complex disease and that cell-type-specific binding of transcription factors (TF) is critical to gene regulation, but genomic annotations from directly measured TF binding information are not currently available for most cell-type-TF pairs. Here, we construct cell-type-specific TF binding annotations by intersecting sequence-based TF binding predictions with cell-type-specific chromatin data; this strategy addresses both the limitation that identical sequences may be bound or unbound depending on surrounding chromatin context, and the limitation that sequence-based predictions are generally not cell-type-specific. We evaluated different combinations of sequence-based TF predictions and chromatin data by partitioning the heritability of 49 diseases and complex traits (average N=320K) using stratified LD score regression with the baseline-LD model (which is not cell-type-specific). We determined that 100bp windows around MotifMap sequenced-based TF binding predictions intersected with a union of six cell-type-specific chromatin marks (imputed using ChromImpute) performed best, with an 58% increase in heritability enrichment compared to the chromatin marks alone (11.6x vs 7.3x; P = 9 × 10-14 for difference) and a 12% increase in cell-type-specific signal conditional on annotations from the baseline-LD model (P = 8 × 10-11 for difference). Our results show that intersecting sequence-based TF predictions with cell-type-specific chromatin information can help refine genome-wide association signals.


2015 ◽  
Author(s):  
Hilary Kiyo Finucane ◽  
Brendan Bulik-Sullivan ◽  
Alexander Gusev ◽  
Gosia Trynka ◽  
Yakir Reshef ◽  
...  

Recent work has demonstrated that some functional categories of the genome contribute disproportionately to the heritability of complex diseases. Here, we analyze a broad set of functional elements, including cell-type-specific elements, to estimate their polygenic contributions to heritability in genome-wide association studies (GWAS) of 17 complex diseases and traits spanning a total of 1.3 million phenotype measurements. To enable this analysis, we introduce a new method for partitioning heritability from GWAS summary statistics while controlling for linked markers. This new method is computationally tractable at very large sample sizes, and leverages genome-wide information. Our results include a large enrichment of heritability in conserved regions across many traits; a very large immunological disease-specific enrichment of heritability in FANTOM5 enhancers; and many cell-type-specific enrichments including significant enrichment of central nervous system cell types in body mass index, age at menarche, educational attainment, and smoking behavior. These results demonstrate that GWAS can aid in understanding the biological basis of disease and provide direction for functional follow-up.


2020 ◽  
Author(s):  
Álvaro Inglés-Prieto ◽  
Nikolas Furthmann ◽  
Samuel Crossman ◽  
Nina Hoyer ◽  
Meike Petersen ◽  
...  

AbstractOptogenetics has been harnessed to shed new mechanistic light on current therapies and to develop future treatment strategies. This has been to date achieved by the correction of electrical signals in neuronal cells and neural circuits that are affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and thereby may modify progression of degenerative disorders, has never been demonstrated in an animal disease model. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson’s disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to overcome limitations of current strategies towards a spatio-temporal regulation of tissue repair.Significance StatementThe death of physiologically important cell populations underlies of a wide range of degenerative disorders, including Parkinson’s disease (PD). Two major strategies to counter cell degeneration, soluble growth factor injection and growth factor gene therapy, can lead to the undesired activation of bystander cells and non-natural permanent signaling responses. Here, we employed optogenetics to deliver cell type-specific pro-survival signals in a genetic model of PD. In Drosophila and human cells exhibiting loss of the PINK1 kinase, akin to autosomal recessive PD, we efficiently suppressed disease phenotypes using a light-activated tyrosine kinase receptor. This work demonstrates a spatio-temporally precise strategy to interfere with degeneration and may open new avenues towards tissue repair in disease models.


2019 ◽  
Author(s):  
Hyeon-Jin Kim ◽  
Galip Gürkan Yardımcı ◽  
Giancarlo Bonora ◽  
Vijay Ramani ◽  
Jie Liu ◽  
...  

AbstractSingle-cell Hi-C (scHi-C) interrogates genome-wide chromatin interaction in individual cells, allowing us to gain insights into 3D genome organization. However, the extremely sparse nature of scHi-C data poses a significant barrier to analysis, limiting our ability to tease out hidden biological information. In this work, we approach this problem by applying topic modeling to scHi-C data. Topic modeling is well-suited for discovering latent topics in a collection of discrete data. For our analysis, we generate twelve different single-cell combinatorial indexed Hi-C (sciHi-C) libraries from five human cell lines (GM12878, H1Esc, HFF, IMR90, and HAP1), consisting over 25,000 cells. We demonstrate that topic modeling is able to successfully capture cell type differences from sciHi-C data in the form of “chromatin topics.” We further show enrichment of particular compartment structures associated with locus pairs in these topics.


2019 ◽  
Author(s):  
Igor Mačinković ◽  
Ina Theofel ◽  
Tim Hundertmark ◽  
Kristina Kovač ◽  
Stephan Awe ◽  
...  

Abstract CoREST has been identified as a subunit of several protein complexes that generate transcriptionally repressive chromatin structures during development. However, a comprehensive analysis of the CoREST interactome has not been carried out. We use proteomic approaches to define the interactomes of two dCoREST isoforms, dCoREST-L and dCoREST-M, in Drosophila. We identify three distinct histone deacetylase complexes built around a common dCoREST/dRPD3 core: A dLSD1/dCoREST complex, the LINT complex and a dG9a/dCoREST complex. The latter two complexes can incorporate both dCoREST isoforms. By contrast, the dLSD1/dCoREST complex exclusively assembles with the dCoREST-L isoform. Genome-wide studies show that the three dCoREST complexes associate with chromatin predominantly at promoters. Transcriptome analyses in S2 cells and testes reveal that different cell lineages utilize distinct dCoREST complexes to maintain cell-type-specific gene expression programmes: In macrophage-like S2 cells, LINT represses germ line-related genes whereas other dCoREST complexes are largely dispensable. By contrast, in testes, the dLSD1/dCoREST complex prevents transcription of germ line-inappropriate genes and is essential for spermatogenesis and fertility, whereas depletion of other dCoREST complexes has no effect. Our study uncovers three distinct dCoREST complexes that function in a lineage-restricted fashion to repress specific sets of genes thereby maintaining cell-type-specific gene expression programmes.


Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 937 ◽  
Author(s):  
Derya Kabacaoglu ◽  
Dietrich A. Ruess ◽  
Jiaoyu Ai ◽  
Hana Algül

Regulation of Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/Rel transcription factors (TFs) is extremely cell-type-specific owing to their ability to act disparately in the context of cellular homeostasis driven by cellular fate and the microenvironment. This is also valid for tumor cells in which every single component shows heterogenic effects. Whereas many studies highlighted a per se oncogenic function for NF-κB/Rel TFs across cancers, recent advances in the field revealed their additional tumor-suppressive nature. Specifically, pancreatic ductal adenocarcinoma (PDAC), as one of the deadliest malignant diseases, shows aberrant canonical-noncanonical NF-κB signaling activity. Although decades of work suggest a prominent oncogenic activity of NF-κB signaling in PDAC, emerging evidence points to the opposite including anti-tumor effects. Considering the dual nature of NF-κB signaling and how it is closely linked to many other cancer related signaling pathways, it is essential to dissect the roles of individual Rel TFs in pancreatic carcinogenesis and tumor persistency and progression. Here, we discuss recent knowledge highlighting the role of Rel TFs RelA, RelB, and c-Rel in PDAC development and maintenance. Next to providing rationales for therapeutically harnessing Rel TF function in PDAC, we compile strategies currently in (pre-)clinical evaluation.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Jun Wang ◽  
Liangjiang Wang

Abstract N6-adenosine methylation (m6A) is the most abundant internal RNA modification in eukaryotes, and affects RNA metabolism and non-coding RNA function. Previous studies suggest that m6A modifications in mammals occur on the consensus sequence DRACH (D = A/G/U, R = A/G, H = A/C/U). However, only about 10% of such adenosines can be m6A-methylated, and the underlying sequence determinants are still unclear. Notably, the regulation of m6A modifications can be cell-type-specific. In this study, we have developed a deep learning model, called TDm6A, to predict RNA m6A modifications in human cells. For cell types with limited availability of m6A data, transfer learning may be used to enhance TDm6A model performance. We show that TDm6A can learn common and cell-type-specific motifs, some of which are associated with RNA-binding proteins previously reported to be m6A readers or anti-readers. In addition, we have used TDm6A to predict m6A sites on human long non-coding RNAs (lncRNAs) for selection of candidates with high levels of m6A modifications. The results provide new insights into m6A modifications on human protein-coding and non-coding transcripts.


Author(s):  
Xiangyu Luo ◽  
Joel Schwartz ◽  
Andrea Baccarelli ◽  
Zhonghua Liu

Abstract Epigenome-wide mediation analysis aims to identify DNA methylation CpG sites that mediate the causal effects of genetic/environmental exposures on health outcomes. However, DNA methylations in the peripheral blood tissues are usually measured at the bulk level based on a heterogeneous population of white blood cells. Using the bulk level DNA methylation data in mediation analysis might cause confounding bias and reduce study power. Therefore, it is crucial to get fine-grained results by detecting mediation CpG sites in a cell-type-specific way. However, there is a lack of methods and software to achieve this goal. We propose a novel method (Mediation In a Cell-type-Specific fashion, MICS) to identify cell-type-specific mediation effects in genome-wide epigenetic studies using only the bulk-level DNA methylation data. MICS follows the standard mediation analysis paradigm and consists of three key steps. In step1, we assess the exposure-mediator association for each cell type; in step 2, we assess the mediator-outcome association for each cell type; in step 3, we combine the cell-type-specific exposure-mediator and mediator-outcome associations using a multiple testing procedure named MultiMed [Sampson JN, Boca SM, Moore SC, et al. FWER and FDR control when testing multiple mediators. Bioinformatics 2018;34:2418–24] to identify significant CpGs with cell-type-specific mediation effects. We conduct simulation studies to demonstrate that our method has correct FDR control. We also apply the MICS procedure to the Normative Aging Study and identify nine DNA methylation CpG sites in the lymphocytes that might mediate the effect of cigarette smoking on the lung function.


Blood ◽  
2012 ◽  
Vol 119 (24) ◽  
pp. e161-e171 ◽  
Author(s):  
Thu-Hang Pham ◽  
Christopher Benner ◽  
Monika Lichtinger ◽  
Lucia Schwarzfischer ◽  
Yuhui Hu ◽  
...  

Abstract Cellular differentiation is orchestrated by lineage-specific transcription factors and associated with cell type–specific epigenetic signatures. In the present study, we used stage-specific, epigenetic “fingerprints” to deduce key transcriptional regulators of the human monocytic differentiation process. We globally mapped the distribution of epigenetic enhancer marks (histone H3 lysine 4 monomethylation, histone H3 lysine 27 acetylation, and the histone variant H2AZ), describe general properties of marked regions, and show that cell type–specific epigenetic “fingerprints” are correlated with specific, de novo–derived motif signatures at all of the differentiation stages studied (ie, hematopoietic stem cells, monocytes, and macrophages). We validated the novel, de novo–derived, macrophage-specific enhancer signature, which included ETS, CEBP, bZIP, EGR, E-Box and NF-κB motifs, by ChIP sequencing for a subset of motif corresponding transcription factors (PU.1, C/EBPβ, and EGR2), confirming their association with differentiation-associated epigenetic changes. We describe herein the dynamic enhancer landscape of human macrophage differentiation, highlight the power of genome-wide epigenetic profiling studies to reveal novel functional insights, and provide a unique resource for macrophage biologists.


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