1
|
Taskiran II, Spanier KI, Dickmänken H, Kempynck N, Pančíková A, Ekşi EC, Hulselmans G, Ismail JN, Theunis K, Vandepoel R, Christiaens V, Mauduit D, Aerts S. Cell-type-directed design of synthetic enhancers. Nature 2024; 626:212-220. [PMID: 38086419 PMCID: PMC10830415 DOI: 10.1038/s41586-023-06936-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 12/05/2023] [Indexed: 01/19/2024]
Abstract
Transcriptional enhancers act as docking stations for combinations of transcription factors and thereby regulate spatiotemporal activation of their target genes1. It has been a long-standing goal in the field to decode the regulatory logic of an enhancer and to understand the details of how spatiotemporal gene expression is encoded in an enhancer sequence. Here we show that deep learning models2-6, can be used to efficiently design synthetic, cell-type-specific enhancers, starting from random sequences, and that this optimization process allows detailed tracing of enhancer features at single-nucleotide resolution. We evaluate the function of fully synthetic enhancers to specifically target Kenyon cells or glial cells in the fruit fly brain using transgenic animals. We further exploit enhancer design to create 'dual-code' enhancers that target two cell types and minimal enhancers smaller than 50 base pairs that are fully functional. By examining the state space searches towards local optima, we characterize enhancer codes through the strength, combination and arrangement of transcription factor activator and transcription factor repressor motifs. Finally, we apply the same strategies to successfully design human enhancers, which adhere to enhancer rules similar to those of Drosophila enhancers. Enhancer design guided by deep learning leads to better understanding of how enhancers work and shows that their code can be exploited to manipulate cell states.
Collapse
Affiliation(s)
- Ibrahim I Taskiran
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Katina I Spanier
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Hannah Dickmänken
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Niklas Kempynck
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Alexandra Pančíková
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
- VIB-KULeuven Center for Cancer Biology, Leuven, Belgium
| | - Eren Can Ekşi
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Gert Hulselmans
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Joy N Ismail
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
- UK Dementia Research Institute at Imperial College London, London, UK
| | - Koen Theunis
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Roel Vandepoel
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Valerie Christiaens
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - David Mauduit
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Stein Aerts
- Laboratory of Computational Biology, VIB Center for AI & Computational Biology (VIB.AI), Leuven, Belgium.
- VIB-KULeuven Center for Brain & Disease Research, Leuven, Belgium.
- Department of Human Genetics, KU Leuven, Leuven, Belgium.
| |
Collapse
|
2
|
Ismail JN, Mantash S, Hallal M, Jabado N, Khoueiry P, Shirinian M. Phenotypic and transcriptomic impact of expressing mammalian TET2 in the Drosophila melanogaster model. Epigenetics 2023; 18:2192375. [PMID: 36989121 PMCID: PMC10072067 DOI: 10.1080/15592294.2023.2192375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
Ten-Eleven Translocation (TET) proteins have recently come to light as important epigenetic regulators conserved in multicellular organisms. TET knockdown studies in rodents have highlighted the critical role of these proteins for proper brain development and function. Mutations in mammalian mTET proteins and mTET2 specifically are frequent and deregulated in leukaemia and glioma respectively. Accordingly, we examined the role of mTET2 in tumorigenesis in larval haemocytes and adult heads in Drosophila melanogaster. Our findings showed that expression of mutant and wild type mTET2 resulted in general phenotypic defects in adult flies and accumulation of abdominal melanotic masses. Notably, flies with mTET2-R43G mutation at the N-terminus of mTET2 exhibited locomotor and circadian behavioural deficits, as well as reduced lifespan. Flies with mTET2-R1261C mutation in the catalytic domain, a common mutation in acute myeloid leukaemia (AML), displayed alterations affecting haemocyte haemostasis. Using transcriptomic approach, we identified upregulated immune genes in fly heads that were not exclusive to TET2 mutants but also found in wild type mTET2 flies. Furthermore, inhibiting expression of genes that were found to be deregulated in mTET2 mutants, such as those involved in immune pathways, autophagy, and transcriptional regulation, led to a rescue in fly survival, behaviour, and hemocyte number. This study identifies the transcriptomic profile of wild type mTET2 versus mTET2 mutants (catalytic versus non-catalytic) with indications of TET2 role in normal central nervous system (CNS) function and innate immunity.
Collapse
Affiliation(s)
- Joy N Ismail
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Sarah Mantash
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Mohammad Hallal
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Biomedical Engineering Program, American University of Beirut, Beirut, Lebanon
| | - Nada Jabado
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Pierre Khoueiry
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Pillar Genomics Institute, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Margret Shirinian
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| |
Collapse
|
3
|
De Rop FV, Ismail JN, Bravo González-Blas C, Hulselmans GJ, Flerin CC, Janssens J, Theunis K, Christiaens VM, Wouters J, Marcassa G, de Wit J, Poovathingal S, Aerts S. Hydrop enables droplet-based single-cell ATAC-seq and single-cell RNA-seq using dissolvable hydrogel beads. eLife 2022; 11:e73971. [PMID: 35195064 PMCID: PMC8993220 DOI: 10.7554/elife.73971] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Single-cell RNA-seq and single-cell assay for transposase-accessible chromatin (ATAC-seq) technologies are used extensively to create cell type atlases for a wide range of organisms, tissues, and disease processes. To increase the scale of these atlases, lower the cost and pave the way for more specialized multiome assays, custom droplet microfluidics may provide solutions complementary to commercial setups. We developed HyDrop, a flexible and open-source droplet microfluidic platform encompassing three protocols. The first protocol involves creating dissolvable hydrogel beads with custom oligos that can be released in the droplets. In the second protocol, we demonstrate the use of these beads for HyDrop-ATAC, a low-cost noncommercial scATAC-seq protocol in droplets. After validating HyDrop-ATAC, we applied it to flash-frozen mouse cortex and generated 7996 high-quality single-cell chromatin accessibility profiles in a single run. In the third protocol, we adapt both the reaction chemistry and the capture sequence of the barcoded hydrogel bead to capture mRNA, and demonstrate a significant improvement in throughput and sensitivity compared to previous open-source droplet-based scRNA-seq assays (Drop-seq and inDrop). Similarly, we applied HyDrop-RNA to flash-frozen mouse cortex and generated 9508 single-cell transcriptomes closely matching reference single-cell gene expression data. Finally, we leveraged HyDrop-RNA's high capture rate to analyze a small population of fluorescence-activated cell sorted neurons from the Drosophila brain, confirming the protocol's applicability to low input samples and small cells. HyDrop is currently capable of generating single-cell data in high throughput and at a reduced cost compared to commercial methods, and we envision that HyDrop can be further developed to be compatible with novel (multi) omics protocols.
Collapse
Affiliation(s)
- Florian V De Rop
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Joy N Ismail
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Carmen Bravo González-Blas
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Gert J Hulselmans
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Christopher Campbell Flerin
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research NetworkChevy ChaseUnited States
| | - Jasper Janssens
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Koen Theunis
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research NetworkChevy ChaseUnited States
| | - Valerie M Christiaens
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Jasper Wouters
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Gabriele Marcassa
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Synapse Biology, Department of Neurosciences, KU LeuvenLeuvenBelgium
| | - Joris de Wit
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Synapse Biology, Department of Neurosciences, KU LeuvenLeuvenBelgium
| | | | - Stein Aerts
- VIB-KU Leuven/VIB Center for Brain & Disease ResearchLeuvenBelgium
- Laboratory of Computational Biology, Department of Human Genetics, KU LeuvenLeuvenBelgium
| |
Collapse
|
4
|
Janssens J, Aibar S, Taskiran II, Ismail JN, Gomez AE, Aughey G, Spanier KI, De Rop FV, González-Blas CB, Dionne M, Grimes K, Quan XJ, Papasokrati D, Hulselmans G, Makhzami S, De Waegeneer M, Christiaens V, Southall T, Aerts S. Decoding gene regulation in the fly brain. Nature 2022; 601:630-636. [PMID: 34987221 DOI: 10.1038/s41586-021-04262-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 11/17/2021] [Indexed: 12/13/2022]
Abstract
The Drosophila brain is a frequently used model in neuroscience. Single-cell transcriptome analysis1-6, three-dimensional morphological classification7 and electron microscopy mapping of the connectome8,9 have revealed an immense diversity of neuronal and glial cell types that underlie an array of functional and behavioural traits in the fly. The identities of these cell types are controlled by gene regulatory networks (GRNs), involving combinations of transcription factors that bind to genomic enhancers to regulate their target genes. Here, to characterize GRNs at the cell-type level in the fly brain, we profiled the chromatin accessibility of 240,919 single cells spanning 9 developmental timepoints and integrated these data with single-cell transcriptomes. We identify more than 95,000 regulatory regions that are used in different neuronal cell types, of which 70,000 are linked to developmental trajectories involving neurogenesis, reprogramming and maturation. For 40 cell types, uniquely accessible regions were associated with their expressed transcription factors and downstream target genes through a combination of motif discovery, network inference and deep learning, creating enhancer GRNs. The enhancer architectures revealed by DeepFlyBrain lead to a better understanding of neuronal regulatory diversity and can be used to design genetic driver lines for cell types at specific timepoints, facilitating their characterization and manipulation.
Collapse
Affiliation(s)
- Jasper Janssens
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Sara Aibar
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Ibrahim Ihsan Taskiran
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Joy N Ismail
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | | | - Gabriel Aughey
- Department of Life Sciences, Imperial College London, London, UK
| | - Katina I Spanier
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Florian V De Rop
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Carmen Bravo González-Blas
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Marc Dionne
- Department of Life Sciences, Imperial College London, London, UK
| | - Krista Grimes
- Department of Life Sciences, Imperial College London, London, UK
| | - Xiao Jiang Quan
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Dafni Papasokrati
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Gert Hulselmans
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Samira Makhzami
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Maxime De Waegeneer
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Valerie Christiaens
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Tony Southall
- Department of Life Sciences, Imperial College London, London, UK
| | - Stein Aerts
- VIB Center for Brain & Disease Research, Leuven, Belgium. .,Department of Human Genetics, KU Leuven, Leuven, Belgium.
| |
Collapse
|
5
|
Ismail JN, Ghannam M, Al Outa A, Frey F, Shirinian M. Ten-eleven translocation proteins and their role beyond DNA demethylation - what we can learn from the fly. Epigenetics 2020; 15:1139-1150. [PMID: 32419604 DOI: 10.1080/15592294.2020.1767323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Ten-eleven Translocation (TET) proteins have emerged as a family of epigenetic regulators that are important during development and have been implicated in various types of cancers. TET is a highly conserved protein that has orthologues in almost all multicellular organisms. Here, we review recent literature on the novel substrate specificity of this family of DNA 5-methylcytosine demethylases on DNA 6-methyladenine and RNA 5-methylcytosine that were first identified in the invertebrate model Drosophila. We focus on the biological role of these novel epigenetic marks in the fruit fly and mammals and highlight TET proteins' critical function during development specifically in brain development.
Collapse
Affiliation(s)
- Joy N Ismail
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut , Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center , Beirut, Lebanon
| | - Mirna Ghannam
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut , Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center , Beirut, Lebanon
| | - Amani Al Outa
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut , Beirut, Lebanon
| | - Felice Frey
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut , Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center , Beirut, Lebanon
| | - Margret Shirinian
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut , Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center , Beirut, Lebanon
| |
Collapse
|
6
|
Ismail JN, Badini S, Frey F, Abou-Kheir W, Shirinian M. Drosophila Tet Is Expressed in Midline Glia and Is Required for Proper Axonal Development. Front Cell Neurosci 2019; 13:252. [PMID: 31213988 PMCID: PMC6558204 DOI: 10.3389/fncel.2019.00252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/20/2019] [Indexed: 01/10/2023] Open
Abstract
Ten-Eleven Translocation (TET) proteins are important epigenetic regulators that play a key role in development and are frequently deregulated in cancer. Drosophila melanogaster has a single homologous Tet gene (dTet) that is highly expressed in the central nervous system during development. Here, we examined the expression pattern of dTet in the third instar larval CNS and discovered its presence in a specific set of glia cells: midline glia (MG). Moreover, dTet knockdown resulted in significant lethality, locomotor dysfunction, and alterations in axon patterning in the larval ventral nerve cord. Molecular analyses on dTet knockdown larvae showed a downregulation in genes involved in axon guidance and reduced expression of the axon guidance cue Slit. Our findings point toward a potential role for dTet in midline glial function, specifically the regulation of axon patterning during neurodevelopment.
Collapse
Affiliation(s)
- Joy N Ismail
- Department of Experimental Pathology and Immunology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Shireen Badini
- Department of Experimental Pathology and Immunology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Felice Frey
- Department of Experimental Pathology and Immunology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Wassim Abou-Kheir
- Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Margret Shirinian
- Department of Experimental Pathology and Immunology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| |
Collapse
|