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Jalili V, Cremona MA, Palluzzi F. Rescuing biologically relevant consensus regions across replicated samples. BMC Bioinformatics 2023; 24:240. [PMID: 37286963 PMCID: PMC10246347 DOI: 10.1186/s12859-023-05340-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 05/16/2023] [Indexed: 06/09/2023] Open
Abstract
BACKGROUND Protein-DNA binding sites of ChIP-seq experiments are identified where the binding affinity is significant based on a given threshold. The choice of the threshold is a trade-off between conservative region identification and discarding weak, but true binding sites. RESULTS We rescue weak binding sites using MSPC, which efficiently exploits replicates to lower the threshold required to identify a site while keeping a low false-positive rate, and we compare it to IDR, a widely used post-processing method for identifying highly reproducible peaks across replicates. We observe several master transcription regulators (e.g., SP1 and GATA3) and HDAC2-GATA1 regulatory networks on rescued regions in K562 cell line. CONCLUSIONS We argue the biological relevance of weak binding sites and the information they add when rescued by MSPC. An implementation of the proposed extended MSPC methodology and the scripts to reproduce the performed analysis are freely available at https://genometric.github.io/MSPC/ ; MSPC is distributed as a command-line application and an R package available from Bioconductor ( https://doi.org/doi:10.18129/B9.bioc.rmspc ).
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Affiliation(s)
- Vahid Jalili
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Marzia A Cremona
- Department of Operations and Decision Systems, Université Laval, Quebec, Canada.
- CHU de Québec - Université Laval Research Center, Quebec, Canada.
| | - Fernando Palluzzi
- Department of Brain and Behavioral Sciences, Università di Pavia, Pavia, Italy.
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Murtaj V, Butti E, Martino G, Panina-Bordignon P. Endogenous neural stem cells characterization using omics approaches: Current knowledge in health and disease. Front Cell Neurosci 2023; 17:1125785. [PMID: 37091923 PMCID: PMC10113633 DOI: 10.3389/fncel.2023.1125785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/03/2023] [Indexed: 04/08/2023] Open
Abstract
Neural stem cells (NSCs), an invaluable source of neuronal and glial progeny, have been widely interrogated in the last twenty years, mainly to understand their therapeutic potential. Most of the studies were performed with cells derived from pluripotent stem cells of either rodents or humans, and have mainly focused on their potential in regenerative medicine. High-throughput omics technologies, such as transcriptomics, epigenetics, proteomics, and metabolomics, which exploded in the past decade, represent a powerful tool to investigate the molecular mechanisms characterizing the heterogeneity of endogenous NSCs. The transition from bulk studies to single cell approaches brought significant insights by revealing complex system phenotypes, from the molecular to the organism level. Here, we will discuss the current literature that has been greatly enriched in the “omics era”, successfully exploring the nature and function of endogenous NSCs and the process of neurogenesis. Overall, the information obtained from omics studies of endogenous NSCs provides a sharper picture of NSCs function during neurodevelopment in healthy and in perturbed environments.
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Affiliation(s)
- Valentina Murtaj
- Division of Neuroscience, San Raffaele Vita-Salute University, Milan, Italy
- Neuroimmunology, Division of Neuroscience, Institute of Experimental Neurology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Erica Butti
- Neuroimmunology, Division of Neuroscience, Institute of Experimental Neurology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Gianvito Martino
- Division of Neuroscience, San Raffaele Vita-Salute University, Milan, Italy
- Neuroimmunology, Division of Neuroscience, Institute of Experimental Neurology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Paola Panina-Bordignon
- Division of Neuroscience, San Raffaele Vita-Salute University, Milan, Italy
- Neuroimmunology, Division of Neuroscience, Institute of Experimental Neurology, IRCCS Ospedale San Raffaele, Milan, Italy
- *Correspondence: Paola Panina-Bordignon
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Wu X, Liu S, Liang G. Detecting clusters of transcription factors based on a nonhomogeneous poisson process model. BMC Bioinformatics 2022; 23:535. [PMID: 36494794 PMCID: PMC9738027 DOI: 10.1186/s12859-022-05090-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Rapidly growing genome-wide ChIP-seq data have provided unprecedented opportunities to explore transcription factor (TF) binding under various cellular conditions. Despite the rich resources, development of analytical methods for studying the interaction among TFs in gene regulation still lags behind. RESULTS In order to address cooperative TF binding and detect TF clusters with coordinative functions, we have developed novel computational methods based on clustering the sample paths of nonhomogeneous Poisson processes. Simulation studies demonstrated the capability of these methods to accurately detect TF clusters and uncover the hierarchy of TF interactions. A further application to the multiple-TF ChIP-seq data in mouse embryonic stem cells (ESCs) showed that our methods identified the cluster of core ESC regulators reported in the literature and provided new insights on functional implications of transcrisptional regulatory modules. CONCLUSIONS Effective analytical tools are essential for studying protein-DNA relations. Information derived from this research will help us better understand the orchestration of transcription factors in gene regulation processes.
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Affiliation(s)
- Xiaowei Wu
- grid.438526.e0000 0001 0694 4940Department of Statistics, Virginia Tech, 250 Drillfield Drive, Blacksburg, VA 24061 USA
| | - Shicheng Liu
- grid.438526.e0000 0001 0694 4940Department of Mathematics, Virginia Tech, 225 Stanger Street, Blacksburg, VA 24061 USA
| | - Guanying Liang
- grid.438526.e0000 0001 0694 4940Department of Mathematics, Virginia Tech, 225 Stanger Street, Blacksburg, VA 24061 USA
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Transcriptome Analysis and Intraspecific Variation in Spanish Fir ( Abies pinsapo Boiss.). Int J Mol Sci 2022; 23:ijms23169351. [PMID: 36012612 PMCID: PMC9409315 DOI: 10.3390/ijms23169351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/10/2022] [Accepted: 08/17/2022] [Indexed: 11/16/2022] Open
Abstract
Spanish fir (Abies pinsapo Boiss.) is an endemic, endangered tree that has been scarcely investigated at the molecular level. In this work, the transcriptome of Spanish fir was assembled, providing a large catalog of expressed genes (22,769), within which a high proportion were full-length transcripts (12,545). This resource is valuable for functional genomics studies and genome annotation in this relict conifer species. Two intraspecific variations of A. pinsapo can be found within its largest population at the Sierra de las Nieves National Park: one with standard green needles and another with bluish-green needles. To elucidate the causes of both phenotypes, we studied different physiological and molecular markers and transcriptome profiles in the needles. "Green" trees showed higher electron transport efficiency and enhanced levels of chlorophyll, protein, and total nitrogen in the needles. In contrast, needles from "bluish" trees exhibited higher contents of carotenoids and cellulose. These results agreed with the differential transcriptomic profiles, suggesting an imbalance in the nitrogen status of "bluish" trees. Additionally, gene expression analyses suggested that these differences could be associated with different epigenomic profiles. Taken together, the reported data provide new transcriptome resources and a better understanding of the natural variation in this tree species, which can help improve guidelines for its conservation and the implementation of adaptive management strategies under climatic change.
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Faux T, Rytkönen KT, Mahmoudian M, Paulin N, Junttila S, Laiho A, Elo LL. Differential ATAC-seq and ChIP-seq peak detection using ROTS. NAR Genom Bioinform 2021; 3:lqab059. [PMID: 34235431 PMCID: PMC8253552 DOI: 10.1093/nargab/lqab059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/12/2021] [Accepted: 06/11/2021] [Indexed: 12/30/2022] Open
Abstract
Changes in cellular chromatin states fine-tune transcriptional output and ultimately lead to phenotypic changes. Here we propose a novel application of our reproducibility-optimized test statistics (ROTS) to detect differential chromatin states (ATAC-seq) or differential chromatin modification states (ChIP-seq) between conditions. We compare the performance of ROTS to existing and widely used methods for ATAC-seq and ChIP-seq data using both synthetic and real datasets. Our results show that ROTS outperformed other commonly used methods when analyzing ATAC-seq data. ROTS also displayed the most accurate detection of small differences when modeling with synthetic data. We observed that two-step methods that require the use of a separate peak caller often more accurately called enrichment borders, whereas one-step methods without a separate peak calling step were more versatile in calling sub-peaks. The top ranked differential regions detected by the methods had marked correlation with transcriptional differences of the closest genes. Overall, our study provides evidence that ROTS is a useful addition to the available differential peak detection methods to study chromatin and performs especially well when applied to study differential chromatin states in ATAC-seq data.
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Affiliation(s)
- Thomas Faux
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
| | - Kalle T Rytkönen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
- Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20014, Finland
| | - Mehrad Mahmoudian
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
- Department of Future Technologies, University of Turku, FI-20014 Turku, Finland
| | - Niklas Paulin
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
| | - Sini Junttila
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
| | - Asta Laiho
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
| | - Laura L Elo
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
- Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20014, Finland
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Yin L, Banerjee S, Fan J, He J, Lu X, Xie H. Epigenetic regulation of neuronal cell specification inferred with single cell "Omics" data. Comput Struct Biotechnol J 2020; 18:942-952. [PMID: 32368329 PMCID: PMC7184133 DOI: 10.1016/j.csbj.2020.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/04/2020] [Accepted: 04/05/2020] [Indexed: 12/19/2022] Open
Abstract
The brain is a highly complex organ consisting of numerous types of cells with ample diversity at the epigenetic level to achieve distinct gene expression profiles. During neuronal cell specification, transcription factors (TFs) form regulatory modules with chromatin remodeling proteins to initiate the cascade of epigenetic changes. Currently, little is known about brain epigenetic regulatory modules and how they regulate gene expression in a cell-type specific manner. To infer TFs involved in neuronal specification, we applied a recursive motif search approach on the differentially methylated regions identified from single-cell methylomes. The epigenetic transcription regulatory modules (ETRM), including EGR1 and MEF2C, were predicted and the co-expression of TFs in ETRMs were examined with RNA-seq data from single or sorted brain cells using a conditional probability matrix. Lastly, computational predications were validated with EGR1 ChIP-seq data. In addition, methylome and RNA-seq data generated from Egr1 knockout mice supported the essential role of EGR1 in brain epigenome programming, in particular for excitatory neurons. In summary, we demonstrated that brain single cell methylome and RNA-seq data can be integrated to gain a better understanding of how ETRMs control cell specification. The analytical pipeline implemented in this study is freely accessible in the Github repository (https://github.com/Gavin-Yinld/brain_TF).
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Affiliation(s)
- Liduo Yin
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing 100101, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
| | - Sharmi Banerjee
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA 24061, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Jiayi Fan
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Jianlin He
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Xuemei Lu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing 100101, China
| | - Hehuang Xie
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA.,Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, 24061, USA.,School of Neuroscience, Blacksburg, VA, 24061, USA
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7
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Banerjee S, Wei X, Xie H. Recursive Motif Analyses Identify Brain Epigenetic Transcription Regulatory Modules. Comput Struct Biotechnol J 2019; 17:507-515. [PMID: 31011409 PMCID: PMC6462766 DOI: 10.1016/j.csbj.2019.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/12/2019] [Accepted: 04/03/2019] [Indexed: 01/26/2023] Open
Abstract
DNA methylation is an epigenetic modification modulating the structure of DNA molecule and the interactions with its binding proteins. Accumulating large-scale methylation data motivates the development of analytic tools to facilitate methylome data mining. One critical phenomenon associated with dynamic DNA methylation is the altered DNA binding affinity of transcription factors, which plays key roles in gene expression regulation. In this study, we conceived an algorithm to predict epigenetic regulatory modules through recursive motif analyses on differentially methylated loci. A two-step procedure was implemented to first group differentially methylated loci into clusters according to their correlations in methylation profiles and then to repeatedly identify the transcription factor binding motifs significantly enriched in each cluster. We applied this tool on methylome datasets generated for mouse brains which have a lack of DNA demethylation enzymes TET1 or TET2. Compared with wild type control, the differentially methylated CpG sites identified in TET1 knockout mouse brains differed significantly from those determined for TET2 knockout. Transcription factors with zinc finger DNA binding domains including Egr1, Zic3, and Zeb1 were predicted to be associated with TET1 mediated brain methylome programming, while Lhx family members with Homeobox domains were predicted to be associated with TET2 function. Interestingly, genomic loci from a co-methylated cluster often host motifs for transcription factors sharing the same DNA binding domains. Altogether, our study provided a systematic approach for epigenetic regulatory module identification and will help throw light on the interplay of DNA methylation and transcription factors.
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Affiliation(s)
- Sharmi Banerjee
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA 24061, USA.,Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061, USA
| | - Xiaoran Wei
- Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061, USA.,Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA 24061, USA
| | - Hehuang Xie
- Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061, USA.,Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA 24061, USA.,School of Neuroscience, Blacksburg, VA 24061, USA
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