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Molecular diversity and phenotypic pleiotropy of ancient genomic regulatory loci derived from human endogenous retrovirus type H (HERVH) promoter LTR7 and HERVK promoter LTR5_Hs and their contemporary impacts on pathophysiology of Modern Humans. Mol Genet Genomics 2022; 297:1711-1740. [PMID: 36121513 PMCID: PMC9483895 DOI: 10.1007/s00438-022-01954-7] [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: 05/07/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022]
Abstract
Timelines of population-level effects of viruses on humans varied from the evolutionary scale of million years to contemporary spread of viral infections. Correspondingly, these events are exemplified by: (i) emergence of human endogenous retroviruses (HERVs) from ancient germline infections leading to stable integration of viral genomes into human chromosomes; and (ii) wide-spread viral infections reaching a global pandemic state such as the COVID-19 pandemic. Despite significant efforts, understanding of HERV’s roles in governance of genomic regulatory networks, their impacts on primate evolution and development of human-specific physiological and pathological phenotypic traits remains limited. Remarkably, present analyses revealed that expression of a dominant majority of genes (1696 of 1944 genes; 87%) constituting high-confidence down-steam regulatory targets of defined HERV loci was significantly altered in cells infected with the SARS-CoV-2 coronavirus, a pathogen causing the global COVID-19 pandemic. This study focused on defined sub-sets of DNA sequences derived from HERVs that are expressed at specific stages of human preimplantation embryogenesis and exert regulatory actions essential for self-renewal and pluripotency. Evolutionary histories of LTR7/HERVH and LTR5_Hs/HERVK were charted based on evidence of the earliest presence and expansion of highly conserved (HC) LTR sequences. Sequence conservation analyses of most recent releases 17 primate species’ genomes revealed that LTR7/HERVH have entered germlines of primates in Africa after the separation of the New World Monkey lineage, while LTR5_Hs/HERVK successfully colonized primates’ germlines after the segregation of Gibbons’ species. Subsequently, both LTR7 and LTR5_Hs undergo a marked ~ fourfold–fivefold expansion in genomes of Great Apes. Timelines of quantitative expansion of both LTR7 and LTR5_Hs loci during evolution of Great Apes appear to replicate the consensus evolutionary sequence of increasing cognitive and behavioral complexities of non-human primates, which seems particularly striking for LTR7 loci and 11 distinct LTR7 subfamilies. Consistent with previous reports, identified in this study, 351 human-specific (HS) insertions of LTR7 (175 loci) and LTR5_Hs (176 loci) regulatory sequences have been linked to genes implicated in establishment and maintenance of naïve and primed pluripotent states and preimplantation embryogenesis phenotypes. Unexpectedly, HS-LTRs manifest regulatory connectivity to genes encoding markers of 12 distinct cells’ populations of fetal gonads, as well as genes implicated in physiology and pathology of human spermatogenesis, including Y-linked spermatogenic failure, oligo- and azoospermia. Granular interrogations of genes linked with 11 distinct LTR7 subfamilies revealed that mammalian offspring survival (MOS) genes seem to remain one of consistent regulatory targets throughout ~ 30 MYA of the divergent evolution of LTR7 loci. Differential GSEA of MOS versus non-MOS genes identified clearly discernable dominant enrichment patterns of phenotypic traits affected by MOS genes linked with LTR7 (562 MOS genes) and LTR5_Hs (126 MOS genes) regulatory loci across the large panel of genomics and proteomics databases reflecting a broad spectrum of human physiological and pathological traits. GSEA of LTR7-linked MOS genes identified more than 2200 significantly enriched records of human common and rare diseases and gene signatures of 466 significantly enriched records of Human Phenotype Ontology traits, including Autosomal Dominant (92 genes) and Autosomal Recessive (93 genes) Inheritance. LTR7 regulatory elements appear linked with genes implicated in functional and morphological features of central nervous system, including synaptic transmission and protein–protein interactions at synapses, as well as gene signatures differentially regulated in cells of distinct neurodevelopmental stages and morphologically diverse cell types residing and functioning in human brain. These include Neural Stem/Precursor cells, Radial Glia cells, Bergman Glia cells, Pyramidal cells, Tanycytes, Immature neurons, Interneurons, Trigeminal neurons, GABAergic neurons, and Glutamatergic neurons. GSEA of LTR7-linked genes identified significantly enriched gene sets encoding markers of more than 80 specialized types of neurons and markers of 521 human brain regions, most prominently, subiculum and dentate gyrus. Identification and characterization of 1944 genes comprising high-confidence down-steam regulatory targets of LTR7 and/or LTR5_Hs loci validated and extended these observations by documenting marked enrichments for genes implicated in neoplasm metastasis, intellectual disability, autism, multiple cancer types, Alzheimer’s, schizophrenia, and other brain disorders. Overall, genes representing down-stream regulatory targets of ancient retroviral LTRs exert the apparently cooperative and exceedingly broad phenotypic impacts on human physiology and pathology. This is exemplified by altered expression of 93% high-confidence LTR targets in cells infected by contemporary viruses, revealing a convergence of virus-inflicted aberrations on genomic regulatory circuitry governed by ancient retroviral LTR elements and interference with human cells’ differentiation programs.
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Dominant role of DNA methylation over H3K9me3 for IAP silencing in endoderm. Nat Commun 2022; 13:5447. [PMID: 36123357 PMCID: PMC9485127 DOI: 10.1038/s41467-022-32978-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 08/25/2022] [Indexed: 12/03/2022] Open
Abstract
Silencing of endogenous retroviruses (ERVs) is largely mediated by repressive chromatin modifications H3K9me3 and DNA methylation. On ERVs, these modifications are mainly deposited by the histone methyltransferase Setdb1 and by the maintenance DNA methyltransferase Dnmt1. Knock-out of either Setdb1 or Dnmt1 leads to ERV de-repression in various cell types. However, it is currently not known if H3K9me3 and DNA methylation depend on each other for ERV silencing. Here we show that conditional knock-out of Setdb1 in mouse embryonic endoderm results in ERV de-repression in visceral endoderm (VE) descendants and does not occur in definitive endoderm (DE). Deletion of Setdb1 in VE progenitors results in loss of H3K9me3 and reduced DNA methylation of Intracisternal A-particle (IAP) elements, consistent with up-regulation of this ERV family. In DE, loss of Setdb1 does not affect H3K9me3 nor DNA methylation, suggesting Setdb1-independent pathways for maintaining these modifications. Importantly, Dnmt1 knock-out results in IAP de-repression in both visceral and definitive endoderm cells, while H3K9me3 is unaltered. Thus, our data suggest a dominant role of DNA methylation over H3K9me3 for IAP silencing in endoderm cells. Our findings suggest that Setdb1-meditated H3K9me3 is not sufficient for IAP silencing, but rather critical for maintaining high DNA methylation. Silencing of endogenous retroviruses is crucial for maintaining transcriptional and genomic integrity of cells and is maintained by histone H3K9 methylation and/or DNA methylation in various cell types. Here the authors show that loss of DNA methyltransferase DNMT1 in endoderm results in ERV derepression while H3K9me3 is unaltered.
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Ai Z, Xiang X, Xiang Y, Szczerbinska I, Qian Y, Xu X, Ma C, Su Y, Gao B, Shen H, Bin Ramli MN, Chen D, Liu Y, Hao JJ, Ng HH, Zhang D, Chan YS, Liu W, Liang H. Krüppel-like factor 5 rewires NANOG regulatory network to activate human naive pluripotency specific LTR7Ys and promote naive pluripotency. Cell Rep 2022; 40:111240. [PMID: 36001968 DOI: 10.1016/j.celrep.2022.111240] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/06/2022] [Accepted: 07/27/2022] [Indexed: 12/01/2022] Open
Abstract
Endogenous retroviruses (ERVs) have been reported to participate in pre-implantation development of mammalian embryos. In early human embryogenesis, different ERV sub-families are activated in a highly stage-specific manner. How the specificity of ERV activation is achieved remains largely unknown. Here, we demonstrate the mechanism of how LTR7Ys, the human morula-blastocyst-specific HERVH long terminal repeats, are activated by the naive pluripotency transcription network. We find that KLF5 interacts with and rewires NANOG to bind and regulate LTR7Ys; in contrast, the primed-specific LTR7s are preferentially bound by NANOG in the absence of KLF5. The specific activation of LTR7Ys by KLF5 and NANOG in pluripotent stem cells contributes to human-specific naive pluripotency regulation. KLF5-LTR7Y axis also promotes the expression of trophectoderm genes and contributes to the expanded cell potential toward extra-embryonic lineage. Our study suggests that HERVs are activated by cell-state-specific transcription machinery and promote stage-specific transcription network and cell potency.
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Affiliation(s)
- Zhipeng Ai
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, and Institute of Genetics, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Xinyu Xiang
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, 718 East Haizhou Road, Haining 314400, China
| | - Yangquan Xiang
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, and Institute of Genetics, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Iwona Szczerbinska
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore
| | - Yuli Qian
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Xiao Xu
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, and Institute of Genetics, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Chenyang Ma
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, and Institute of Genetics, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Yaqi Su
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, 718 East Haizhou Road, Haining 314400, China
| | - Bing Gao
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, 718 East Haizhou Road, Haining 314400, China
| | - Hao Shen
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, and Institute of Genetics, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Muhammad Nadzim Bin Ramli
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore
| | - Di Chen
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, 718 East Haizhou Road, Haining 314400, China
| | - Yue Liu
- Guangzhou Laboratory, No. 9 Xing Dao Huan Bei Road, Guangzhou International Bio Island, Guangzhou 510005, China
| | - Jia-Jie Hao
- Guangzhou Laboratory, No. 9 Xing Dao Huan Bei Road, Guangzhou International Bio Island, Guangzhou 510005, China
| | - Huck Hui Ng
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117597, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 639798, Singapore
| | - Dan Zhang
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.
| | - Yun-Shen Chan
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore; Guangzhou Laboratory, No. 9 Xing Dao Huan Bei Road, Guangzhou International Bio Island, Guangzhou 510005, China.
| | - Wanlu Liu
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, 718 East Haizhou Road, Haining 314400, China; Department of Orthopedic Surgery of the Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310029, China; Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University, Hangzhou 310058, China.
| | - Hongqing Liang
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, and Institute of Genetics, Zhejiang University School of Medicine, Hangzhou 310006, China.
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Hijacking of transcriptional condensates by endogenous retroviruses. Nat Genet 2022; 54:1238-1247. [PMID: 35864192 PMCID: PMC9355880 DOI: 10.1038/s41588-022-01132-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 05/26/2022] [Indexed: 12/20/2022]
Abstract
Most endogenous retroviruses (ERVs) in mammals are incapable of retrotransposition; therefore, why ERV derepression is associated with lethality during early development has been a mystery. Here, we report that rapid and selective degradation of the heterochromatin adapter protein TRIM28 triggers dissociation of transcriptional condensates from loci encoding super-enhancer (SE)-driven pluripotency genes and their association with transcribed ERV loci in murine embryonic stem cells. Knockdown of ERV RNAs or forced expression of SE-enriched transcription factors rescued condensate localization at SEs in TRIM28-degraded cells. In a biochemical reconstitution system, ERV RNA facilitated partitioning of RNA polymerase II and the Mediator coactivator into phase-separated droplets. In TRIM28 knockout mouse embryos, single-cell RNA-seq analysis revealed specific depletion of pluripotent lineages. We propose that coding and noncoding nascent RNAs, including those produced by retrotransposons, may facilitate ‘hijacking’ of transcriptional condensates in various developmental and disease contexts. TRIM28 depletion in embryonic stem cells disconnects transcriptional condensates from super-enhancers, which is rescued by knockdown of endogenous retroviruses.
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Epigenetics as "conductor" in "orchestra" of pluripotent states. Cell Tissue Res 2022; 390:141-172. [PMID: 35838826 DOI: 10.1007/s00441-022-03667-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 07/01/2022] [Indexed: 11/02/2022]
Abstract
Pluripotent character is described as the potency of cells to differentiate into all three germ layers. The best example to reinstate the term lies in the context of embryonic stem cells (ESCs). Pluripotent ESC describes the in vitro status of those cells that originate during the complex process of embryogenesis. Pre-implantation to post-implantation development of embryo embrace cells with different levels of stemness. Currently, four states of pluripotency have been recognized, in the progressing order of "naïve," "poised," "formative," and "primed." Epigenetics act as the "conductor" in this "orchestra" of transition in pluripotent states. With a distinguishable gene expression profile, these four states associate with different epigenetic signatures, sometimes distinct while otherwise overlapping. The present review focuses on how epigenetic factors, including DNA methylation, bivalent chromatin, chromatin remodelers, chromatin/nuclear architecture, and microRNA, could dictate pluripotent states and their transition among themselves.
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Rashmi R, Majumdar S. Pan-Cancer Analysis Reveals the Prognostic Potential of the THAP9/THAP9-AS1 Sense-Antisense Gene Pair in Human Cancers. Noncoding RNA 2022; 8:ncrna8040051. [PMID: 35893234 PMCID: PMC9326536 DOI: 10.3390/ncrna8040051] [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: 04/05/2022] [Revised: 06/11/2022] [Accepted: 06/13/2022] [Indexed: 11/18/2022] Open
Abstract
Human THAP9, which encodes a domesticated transposase of unknown function, and lncRNA THAP9-AS1 (THAP9-antisense1) are arranged head-to-head on opposite DNA strands, forming a sense and antisense gene pair. We predict that there is a bidirectional promoter that potentially regulates the expression of THAP9 and THAP9-AS1. Although both THAP9 and THAP9-AS1 are reported to be involved in various cancers, their correlative roles on each other’s expression has not been explored. We analyzed the expression levels, prognosis, and predicted biological functions of the two genes across different cancer datasets (TCGA, GTEx). We observed that although the expression levels of the two genes, THAP9 and THAP9-AS1, varied in different tumors, the expression of the gene pair was strongly correlated with patient prognosis; higher expression of the gene pair was usually linked to poor overall and disease-free survival. Thus, THAP9 and THAP9-AS1 may serve as potential clinical biomarkers of tumor prognosis. Further, we performed a gene co-expression analysis (using WGCNA) followed by a differential gene correlation analysis (DGCA) across 22 cancers to identify genes that share the expression pattern of THAP9 and THAP9-AS1. Interestingly, in both normal and cancer samples, THAP9 and THAP9-AS1 often co-express; moreover, their expression is positively correlated in each cancer type, suggesting the coordinated regulation of this H2H gene pair.
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57
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Yu H, Chen M, Hu Y, Ou S, Yu X, Liang S, Li N, Yang M, Kong X, Sun C, Jia S, Zhang Q, Liu L, Hurst LD, Li R, Wang W, Wang J. Dynamic reprogramming of H3K9me3 at hominoid-specific retrotransposons during human preimplantation development. Cell Stem Cell 2022; 29:1031-1050.e12. [PMID: 35803225 DOI: 10.1016/j.stem.2022.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 04/06/2022] [Accepted: 06/08/2022] [Indexed: 12/13/2022]
Abstract
Reprogramming of H3K9me3-dependent heterochromatin is required for early development. How H3K9me3 is involved in early human development remains, however, largely unclear. Here, we resolve the temporal landscape of H3K9me3 during human preimplantation development and its regulation for diverse hominoid-specific retrotransposons. At the 8-cell stage, H3K9me3 reprogramming at hominoid-specific retrotransposons termed SINE-VNTR-Alu (SVA) facilitates interaction between certain promoters and SVA-derived enhancers, promoting the zygotic genome activation. In trophectoderm, de novo H3K9me3 domains prevent pluripotent transcription factors from binding to hominoid-specific retrotransposons-derived regulatory elements for inner cell mass (ICM)-specific genes. H3K9me3 re-establishment at SVA elements in the ICM is associated with higher transcription of DNA repair genes, when compared with naive human pluripotent stem cells. Our data demonstrate that species-specific reorganization of H3K9me3-dependent heterochromatin at hominoid-specific retrotransposons plays important roles during early human development, shedding light on how the epigenetic regulation for early development has evolved in mammals.
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Affiliation(s)
- Hanwen Yu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Manqi Chen
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Yuanlang Hu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China; The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
| | - Songbang Ou
- Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Xiu Yu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Shiqi Liang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Niannian Li
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Mingzhu Yang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Xuhui Kong
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Chuanbo Sun
- Laboratory of Medical Systems Biology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Shiqi Jia
- The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
| | - Qingxue Zhang
- Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Laurence D Hurst
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - Ruiqi Li
- Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.
| | - Wenjun Wang
- Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.
| | - Jichang Wang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China.
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58
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Fueyo R, Judd J, Feschotte C, Wysocka J. Roles of transposable elements in the regulation of mammalian transcription. Nat Rev Mol Cell Biol 2022; 23:481-497. [PMID: 35228718 PMCID: PMC10470143 DOI: 10.1038/s41580-022-00457-y] [Citation(s) in RCA: 123] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2022] [Indexed: 12/16/2022]
Abstract
Transposable elements (TEs) comprise about half of the mammalian genome. TEs often contain sequences capable of recruiting the host transcription machinery, which they use to express their own products and promote transposition. However, the regulatory sequences carried by TEs may affect host transcription long after the TEs have lost the ability to transpose. Recent advances in genome analysis and engineering have facilitated systematic interrogation of the regulatory activities of TEs. In this Review, we discuss diverse mechanisms by which TEs contribute to transcription regulation. Notably, TEs can donate enhancer and promoter sequences that influence the expression of host genes, modify 3D chromatin architecture and give rise to novel regulatory genes, including non-coding RNAs and transcription factors. We discuss how TEs spur regulatory evolution and facilitate the emergence of genetic novelties in mammalian physiology and development. By virtue of their repetitive and interspersed nature, TEs offer unique opportunities to dissect the effects of mutation and genomic context on the function and evolution of cis-regulatory elements. We argue that TE-centric studies hold the key to unlocking general principles of transcription regulation and evolution.
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Affiliation(s)
- Raquel Fueyo
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Julius Judd
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Cedric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
| | - Joanna Wysocka
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA.
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.
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59
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Chang NC, Rovira Q, Wells J, Feschotte C, Vaquerizas JM. Zebrafish transposable elements show extensive diversification in age, genomic distribution, and developmental expression. Genome Res 2022; 32:1408-1423. [PMID: 34987056 PMCID: PMC9341512 DOI: 10.1101/gr.275655.121] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 12/30/2021] [Indexed: 12/02/2022]
Abstract
There is considerable interest in understanding the effect of transposable elements (TEs) on embryonic development. Studies in humans and mice are limited by the difficulty of working with mammalian embryos and by the relative scarcity of active TEs in these organisms. The zebrafish is an outstanding model for the study of vertebrate development, and over half of its genome consists of diverse TEs. However, zebrafish TEs remain poorly characterized. Here we describe the demography and genomic distribution of zebrafish TEs and their expression throughout embryogenesis using bulk and single-cell RNA sequencing data. These results reveal a highly dynamic genomic ecosystem comprising nearly 2000 distinct TE families, which vary in copy number by four orders of magnitude and span a wide range of ages. Longer retroelements tend to be retained in intergenic regions, whereas short interspersed nuclear elements (SINEs) and DNA transposons are more frequently found nearby or within genes. Locus-specific mapping of TE expression reveals extensive TE transcription during development. Although two-thirds of TE transcripts are likely driven by nearby gene promoters, we still observe stage- and tissue-specific expression patterns in self-regulated TEs. Long terminal repeat (LTR) retroelements are most transcriptionally active immediately following zygotic genome activation, whereas DNA transposons are enriched among transcripts expressed in later stages of development. Single-cell analysis reveals several endogenous retroviruses expressed in specific somatic cell lineages. Overall, our study provides a valuable resource for using zebrafish as a model to study the impact of TEs on vertebrate development.
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Affiliation(s)
- Ni-Chen Chang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850, USA
| | - Quirze Rovira
- Max Planck Institute for Molecular Biomedicine, 48149 Muenster, Germany
| | - Jonathan Wells
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850, USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850, USA
| | - Juan M Vaquerizas
- Max Planck Institute for Molecular Biomedicine, 48149 Muenster, Germany
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom
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Yu X, Liang S, Chen M, Yu H, Li R, Qu Y, Kong X, Guo R, Zheng R, Izsvák Z, Sun C, Yang M, Wang J. Recapitulating early human development with 8C-like cells. Cell Rep 2022; 39:110994. [PMID: 35732112 DOI: 10.1016/j.celrep.2022.110994] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/21/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022] Open
Abstract
In human embryos, major zygotic genome activation (ZGA) initiates at the eight-cell (8C) stage. Abnormal ZGA leads to developmental defects and even contributes to the failure of human blastocyst formation or implantation. An in vitro cell model mimicking human 8C blastomeres would be invaluable to understanding the mechanisms regulating key biological events during early human development. Using the non-canonical promoter of LEUTX that putatively regulates human ZGA, we developed an 8C::mCherry reporter, which specifically marks the 8C state, to isolate rare 8C-like cells (8CLCs) from human preimplantation epiblast-like stem cells. The 8CLCs express a panel of human ZGA genes and have a unique transcriptome resembling that of the human 8C embryo. Using the 8C::mCherry reporter, we further optimize the chemical-based culture condition to increase and maintain the 8CLC population. Functionally, 8CLCs can self-organize to form blastocyst-like structures. The discovery and maintenance of 8CLCs provide an opportunity to recapitulate early human development.
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Affiliation(s)
- Xiu Yu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Shiqi Liang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Manqi Chen
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Hanwen Yu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Ruiqi Li
- Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Yuliang Qu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Xuhui Kong
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Ruirui Guo
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Rongyan Zheng
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Zsuzsanna Izsvák
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Chuanbo Sun
- Laboratory of Medical Systems Biology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China.
| | - Mingzhu Yang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China.
| | - Jichang Wang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China.
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61
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Activation of lnc-ALVE1-AS1 inhibited ALV-J replication through triggering the TLR3 pathway in chicken macrophage like cell line. Vet Res Commun 2022; 47:431-443. [PMID: 35715584 DOI: 10.1007/s11259-022-09960-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 06/14/2022] [Indexed: 11/27/2022]
Abstract
Endogenous retroviruses (ERVs) are remnants of the historical retroviral infections, and their derived transcripts with viral signatures are important sources of long noncoding RNAs (lncRNAs). We have previously shown that the chicken ERV-derived lncRNA lnc-ALVE1-AS1 exerts antiviral innate immunity in chicken embryo fibroblasts. However, it is not clear whether this endogenous retroviral RNA has a similar function in immune cells. Here, we found that lnc-ALVE1-AS1 was persistently inhibited in chicken macrophages after avian leukosis virus subgroup J (ALV-J) infection. Furthermore, overexpression of lnc-ALVE1-AS1 significantly inhibited the replication of exogenous ALV-J, whereas knockdown of lnc-ALVE1-AS1 promoted the replication of ALV-J in chicken macrophages. This phenomenon is attributed to the induction of antiviral innate immunity by lnc-ALVE1-AS1 in macrophages, whereas knockdown of lnc-ALVE1-AS1 had the opposite effect. Mechanistically, lnc-ALVE1-AS1 can be sensed by the cytosolic pattern recognition receptor TLR3 and trigger the type I interferons response. The present study provides novel insights into the antiviral defense of ERV-derived lncRNAs in macrophages and offers new strategies for future antiviral solutions.
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62
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Yu C, Lei X, Chen F, Mao S, Lv L, Liu H, Hu X, Wang R, Shen L, Zhang N, Meng Y, Shen Y, Chen J, Li P, Huang S, Lin C, Zhang Z, Yuan K. ARID1A loss derepresses a group of human endogenous retrovirus-H loci to modulate BRD4-dependent transcription. Nat Commun 2022; 13:3501. [PMID: 35715442 PMCID: PMC9205910 DOI: 10.1038/s41467-022-31197-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 06/07/2022] [Indexed: 11/25/2022] Open
Abstract
Transposable elements (TEs) through evolutionary exaptation have become an integral part of the human genome, offering ample regulatory sequences and shaping chromatin 3D architecture. While the functional impacts of TE-derived sequences on early embryogenesis have been recognized, their roles in malignancy are only starting to emerge. Here we show that many TEs, especially the pluripotency-related human endogenous retrovirus H (HERVH), are abnormally activated in colorectal cancer (CRC) samples. Transcriptional upregulation of HERVH is associated with mutations of several tumor suppressors, particularly ARID1A. Knockout of ARID1A in CRC cells leads to increased transcription at several HERVH loci, which involves compensatory contribution by ARID1B. Suppression of HERVH in CRC cells and patient-derived organoids impairs tumor growth. Mechanistically, HERVH transcripts colocalize with nuclear BRD4 foci, modulating their dynamics and co-regulating many target genes. Altogether, we uncover a critical role for ARID1A in restraining HERVH, whose abnormal activation can promote tumorigenesis by stimulating BRD4-dependent transcription. Here the authors show mutation of the BAF chromatin remodeler subunit ARID1A results in an ARID1B-dependent upregulation of HERVH, an ERV required for the pluripotency regulatory network. These HERVH RNAs can partition into BRD4 foci, affecting BRD4-dependent transcription. Suppression of HERVH in colorectal cancer cells and patient-derived organoids impairs tumor growth.
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Affiliation(s)
- Chunhong Yu
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiaoyun Lei
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fang Chen
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Song Mao
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lu Lv
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Honglu Liu
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xueying Hu
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Runhan Wang
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Licong Shen
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Gynecology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Na Zhang
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yang Meng
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yunfan Shen
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Jiale Chen
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Pishun Li
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shi Huang
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Changwei Lin
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Gastrointestinal Surgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhuohua Zhang
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Kai Yuan
- Hunan Key Laboratory of Molecular Precision Medicine, Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,The Biobank of Xiangya Hospital, Central South University, Changsha, Hunan, China.
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63
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Louro AF, Virgolini N, Paiva MA, Isidro IA, Alves PM, Gomes-Alves P, Serra M. Expression of Extracellular Vesicle PIWI-Interacting RNAs Throughout hiPSC-Cardiomyocyte Differentiation. Front Physiol 2022; 13:926528. [PMID: 35784878 PMCID: PMC9243413 DOI: 10.3389/fphys.2022.926528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Extracellular Vesicles (EV) play a critical role in the regulation of regenerative processes in wounded tissues by mediating cell-to-cell communication. Multiple RNA species have been identified in EV, although their function still lacks understanding. We previously characterized the miRNA content of EV secreted over hiPSC-cardiomyocyte differentiation and found a distinct miRNA expression in hiPSC-EV driving its in vitro bioactivity. In this work, we investigated the piRNA profiles of EV derived from key stages of the hiPSC-CM differentiation and maturation, i.e., from hiPSC (hiPSC-EV), cardiac progenitors (CPC-EV), immature (CMi-EV), and mature (CMm-EV) cardiomyocytes, demonstrating that EV-piRNA expression differs greatly from the miRNA profiles we previously identified. Only four piRNA were significantly deregulated in EV, one in hiPSC-EV, and three in CPC-EV, as determined by differential expression analysis on small RNA-seq data. Our results provide a valuable source of information for further studies aiming at defining the role of piRNA in the bioactivity and therapeutic potential of EV.
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64
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Ma G, Babarinde IA, Zhou X, Hutchins AP. Transposable Elements in Pluripotent Stem Cells and Human Disease. Front Genet 2022; 13:902541. [PMID: 35719395 PMCID: PMC9201960 DOI: 10.3389/fgene.2022.902541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/20/2022] [Indexed: 11/18/2022] Open
Abstract
Transposable elements (TEs) are mobile genetic elements that can randomly integrate into other genomic sites. They have successfully replicated and now occupy around 40% of the total DNA sequence in humans. TEs in the genome have a complex relationship with the host cell, being both potentially deleterious and advantageous at the same time. Only a tiny minority of TEs are still capable of transposition, yet their fossilized sequence fragments are thought to be involved in various molecular processes, such as gene transcriptional activity, RNA stability and subcellular localization, and chromosomal architecture. TEs have also been implicated in biological processes, although it is often hard to reveal cause from correlation due to formidable technical issues in analyzing TEs. In this review, we compare and contrast two views of TE activity: one in the pluripotent state, where TEs are broadly beneficial, or at least mechanistically useful, and a second state in human disease, where TEs are uniformly considered harmful.
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65
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Grillo G, Lupien M. Cancer-associated chromatin variants uncover the oncogenic role of transposable elements. Curr Opin Genet Dev 2022; 74:101911. [PMID: 35487182 DOI: 10.1016/j.gde.2022.101911] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/08/2022] [Accepted: 03/24/2022] [Indexed: 11/26/2022]
Abstract
The vast array of cell states found across human tissue arises from chromatin variants, which correspond to segments of the genome, known as DNA elements, adopting a different chromatin state over cell state transitions. Oncogenesis stems from alterations to the chromatin states over DNA elements that result in cancer-associated chromatin variants. Here, we review how cancer-associated chromatin variants call attention to repetitive DNA elements, and guide the functional characterization of transposable elements to decode their role in oncogenesis. We further discuss prevailing opportunities in the study of repetitive DNA elements to move towards the 'complete cancer genome' goal for precision medicine in oncology.
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Affiliation(s)
- Giacomo Grillo
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada.
| | - Mathieu Lupien
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Ontario Institute for Cancer Research, Toronto, Ontario, Canada.
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66
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A retrotransposon storm marks clinical phenoconversion to late-onset Alzheimer's disease. GeroScience 2022; 44:1525-1550. [PMID: 35585302 PMCID: PMC9213607 DOI: 10.1007/s11357-022-00580-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 04/26/2022] [Indexed: 12/03/2022] Open
Abstract
Recent reports have suggested that the reactivation of otherwise transcriptionally silent transposable elements (TEs) might induce brain degeneration, either by dysregulating the expression of genes and pathways implicated in cognitive decline and dementia or through the induction of immune-mediated neuroinflammation resulting in the elimination of neural and glial cells. In the work we present here, we test the hypothesis that differentially expressed TEs in blood could be used as biomarkers of cognitive decline and development of AD. To this aim, we used a sample of aging subjects (age > 70) that developed late-onset Alzheimer’s disease (LOAD) over a relatively short period of time (12–48 months), for which blood was available before and after their phenoconversion, and a group of cognitive stable subjects as controls. We applied our developed and validated customized pipeline that allows the identification, characterization, and quantification of the differentially expressed (DE) TEs before and after the onset of manifest LOAD, through analyses of RNA-Seq data. We compared the level of DE TEs within more than 600,000 TE-mapping RNA transcripts from 25 individuals, whose specimens we obtained before and after their phenotypic conversion (phenoconversion) to LOAD, and discovered that 1790 TE transcripts showed significant expression differences between these two timepoints (logFC ± 1.5, logCMP > 5.3, nominal p value < 0.01). These DE transcripts mapped both over- and under-expressed TE elements. Occurring before the clinical phenoconversion, this TE storm features significant increases in DE transcripts of LINEs, LTRs, and SVAs, while those for SINEs are significantly depleted. These dysregulations end with signs of manifest LOAD. This set of highly DE transcripts generates a TE transcriptional profile that accurately discriminates the before and after phenoconversion states of these subjects. Our findings suggest that a storm of DE TEs occurs before phenoconversion from normal cognition to manifest LOAD in risk individuals compared to controls, and may provide useful blood-based biomarkers for heralding such a clinical transition, also suggesting that TEs can indeed participate in the complex process of neurodegeneration.
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67
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Zhang T, Zheng R, Li M, Yan C, Lan X, Tong B, Lu P, Jiang W. Active endogenous retroviral elements in human pluripotent stem cells play a role in regulating host gene expression. Nucleic Acids Res 2022; 50:4959-4973. [PMID: 35451484 PMCID: PMC9122532 DOI: 10.1093/nar/gkac265] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 03/22/2022] [Accepted: 04/01/2022] [Indexed: 12/20/2022] Open
Abstract
Human endogenous retroviruses, also called LTR elements, can be bound by transcription factors and marked by different histone modifications in different biological contexts. Recently, individual LTR or certain subclasses of LTRs such as LTR7/HERVH and LTR5_Hs/HERVK families have been identified as cis-regulatory elements. However, there are still many LTR elements with unknown functions. Here, we dissected the landscape of histone modifications and regulatory map of LTRs by integrating 98 ChIP-seq data in human embryonic stem cells (ESCs), and annotated the active LTRs enriching enhancer/promoter-related histone marks. Notably, we found that MER57E3 functionally acted as proximal regulatory element to activate respective ZNF gene. Additionally, HERVK transcript could mainly function in nucleus to activate the adjacent genes. Since LTR5_Hs/LTR5 was bound by many early embryo-specific transcription factors, we further investigated the expression dynamics in different pluripotent states. LTR5_Hs/LTR5/HERVK exhibited higher expression level in naïve ESCs and extended pluripotent stem cells (EPSCs). Functionally, the LTR5_Hs/LTR5 with high activity could serve as a distal enhancer to regulate the host genes. Ultimately, our study not only provides a comprehensive regulatory map of LTRs in human ESCs, but also explores the regulatory models of MER57E3 and LTR5_Hs/LTR5 in host genome.
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Affiliation(s)
- Tianzhe Zhang
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Ran Zheng
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Mao Li
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Chenchao Yan
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Xianchun Lan
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Bei Tong
- Department of Cardiology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Pei Lu
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Wei Jiang
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China.,Human Genetics Resource Preservation Center of Wuhan University, Wuhan 430071, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China
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68
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A hypothesis: Retrotransposons as a relay of epigenetic marks in intergenerational epigenetic inheritance. Gene 2022; 817:146229. [PMID: 35063571 DOI: 10.1016/j.gene.2022.146229] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/13/2021] [Accepted: 01/13/2022] [Indexed: 12/19/2022]
Abstract
Epigenetic marks in gametes, which both respond to the parental environmental factors and shape offspring phenotypes, are usually positioned to mediate intergenerational or transgenerational epigenetic inheritance. Nonetheless, the mechanisms through which gametic epigenetic signatures encode parental acquired phenotypes, and further initiate a cascade of molecular events to affect offspring phenotypes during early embryonic development, remain unclear. Retrotransposons are mobile DNA elements that could resist to genomic epigenetic reprogramming at specific loci and rewire the core regulatory networks of embryogenesis. Increasing evidences show that retrotransposons in the embryonic genome could interact with gametic epigenetic marks, which provides a tentative possibility that retrotransposons may serve as a relay of gametic epigenetic marks to transmit parental acquired traits. Here, we summarize the recent progress in exploring the crosstalk between gametic epigenetic marks and retrotransposons, and the regulation of gene expression and early embryonic development by retrotransposons. Accordingly, deciphering the mystery of interactions between gametic epigenetic marks and retrotransposons during early embryonic development will provide valuable insights into the intergenerational or transgenerational transmission of acquired traits.
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69
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van Bree EJ, Guimarães RLFP, Lundberg M, Blujdea ER, Rosenkrantz JL, White FTG, Poppinga J, Ferrer-Raventós P, Schneider AFE, Clayton I, Haussler D, Reinders MJT, Holstege H, Ewing AD, Moses C, Jacobs FMJ. A hidden layer of structural variation in transposable elements reveals potential genetic modifiers in human disease-risk loci. Genome Res 2022; 32:656-670. [PMID: 35332097 PMCID: PMC8997352 DOI: 10.1101/gr.275515.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 01/28/2022] [Indexed: 11/24/2022]
Abstract
Genome-wide association studies (GWAS) have been highly informative in discovering disease-associated loci but are not designed to capture all structural variations in the human genome. Using long-read sequencing data, we discovered widespread structural variation within SINE-VNTR-Alu (SVA) elements, a class of great ape-specific transposable elements with gene-regulatory roles, which represents a major source of structural variability in the human population. We highlight the presence of structurally variable SVAs (SV-SVAs) in neurological disease-associated loci, and we further associate SV-SVAs to disease-associated SNPs and differential gene expression using luciferase assays and expression quantitative trait loci data. Finally, we genetically deleted SV-SVAs in the BIN1 and CD2AP Alzheimer's disease-associated risk loci and in the BCKDK Parkinson's disease-associated risk locus and assessed multiple aspects of their gene-regulatory influence in a human neuronal context. Together, this study reveals a novel layer of genetic variation in transposable elements that may contribute to identification of the structural variants that are the actual drivers of disease associations of GWAS loci.
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Affiliation(s)
- Elisabeth J van Bree
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Rita L F P Guimarães
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands.,Genomics of Neurodegenerative Diseases and Aging, Department of Human Genetics, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands.,Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands
| | - Mischa Lundberg
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Elena R Blujdea
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Jimi L Rosenkrantz
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Fred T G White
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Josse Poppinga
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Paula Ferrer-Raventós
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Anne-Fleur E Schneider
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Isabella Clayton
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - David Haussler
- UC Santa Cruz Genomics Institute, and Howard Hughes Medical Institute, UC Santa Cruz, Santa Cruz, California 95064, USA
| | - Marcel J T Reinders
- Delft Bioinformatics Lab, Delft University of Technology, 2628 XE Delft, The Netherlands
| | - Henne Holstege
- Genomics of Neurodegenerative Diseases and Aging, Department of Human Genetics, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands.,Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands.,Delft Bioinformatics Lab, Delft University of Technology, 2628 XE Delft, The Netherlands.,Amsterdam Neuroscience, Complex Trait Genetics, University of Amsterdam, Amsterdam, The Netherlands
| | - Adam D Ewing
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Colette Moses
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Frank M J Jacobs
- Evolutionary Neurogenomics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands.,Amsterdam Neuroscience, Complex Trait Genetics, University of Amsterdam, Amsterdam, The Netherlands
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70
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Lecuelle J, Favier L, Fraisse C, Lagrange A, Kaderbhai C, Boidot R, Chevrier S, Joubert P, Routy B, Truntzer C, Ghiringhelli F. MER4 endogenous retrovirus correlated with better efficacy of anti-PD1/PD-L1 therapy in non-small cell lung cancer. J Immunother Cancer 2022; 10:jitc-2021-004241. [PMID: 35277462 PMCID: PMC8919440 DOI: 10.1136/jitc-2021-004241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2022] [Indexed: 12/15/2022] Open
Abstract
Background Endogenous retroviruses (ERVs) are highly expressed in various cancer types and are associated with increased innate immune response and better efficacy of antiprogrammed death-1/ligand-1 (anti-PD1/PD-L1)-directed immune checkpoint inhibitors (ICI) in preclinical models. However, their role in human non-small cell lung cancer (NSCLC) remains unknown. Methods We conducted a retrospective study of patients receiving ICI for advanced NSCLC in two independent cohorts. ERV expression was determined by RNA sequencing. The primary endpoint was progression-free survival (PFS) under ICI. The secondary endpoint was overall survival (OS) from ICI initiation. We studied expression of 6205 ERVs. Multivariate Cox regression model with lasso penalty was estimated on the training set to select ERVs significantly associated with survival. The predictive power of these ERVs was compared with that of previously described transcriptomic signatures. Results We studied two independent cohorts of 89 and 70 patients, used as training and validation sets. Clinicopathological characteristics included 75% of patients with non-squamous NSCLC. We selected four ERVs significantly associated with PFS. Only high MER4 ERV was associated with better PFS and OS in both cohorts. From a biological point of view, high MER4 expression is associated with higher infiltration of eosinophils and inflammatory gene signatures, while low MER4 expression is associated with enrichment in metabolism and proliferation signatures. Adding MER4 to previously described transcriptomic signatures of response to ICI improved their predictive power. Conclusions MER4 ERV expression is useful to stratify risk and predict PFS and OS in patients treated with ICI for NSCLC. It also improves the predictive power of other known transcriptomic signatures.
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Affiliation(s)
- Julie Lecuelle
- Platform of Transfer in Biological Oncology, Georges-Francois Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
- UMR INSERM 1231, Dijon, Bourgogne-Franche-Comté, France
- Genomic and Immunotherapy Medical Institute, Dijon University Hospital, Dijon, Bourgogne-Franche-Comté, France
- University of Burgundy-Franche Comté, Dijon, Bourgogne-Franche-Comté, France
| | - Laure Favier
- Departmnt of Medical Oncology, Georges François Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
| | - Cléa Fraisse
- Departmnt of Medical Oncology, Georges François Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
| | - Aurélie Lagrange
- Departmnt of Medical Oncology, Georges François Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
| | - Coureche Kaderbhai
- Departmnt of Medical Oncology, Georges François Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
| | - Romain Boidot
- Department of Biopathology, Georges François Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
| | - Sandy Chevrier
- Department of Biopathology, Georges François Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
| | - Philippe Joubert
- Department of Pathology, Quebec Heart and Lung Institute Research Center, Quebec City, Quebec, Canada
| | - Bertrand Routy
- Department of Medicine Montréal, Division of Oncology, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
- Division of Hematology-Oncology, Centre Hospitalier de l'Université de Montréal (CHUM), Quebec City, Quebec, Canada
| | - Caroline Truntzer
- Platform of Transfer in Biological Oncology, Georges-Francois Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
- UMR INSERM 1231, Dijon, Bourgogne-Franche-Comté, France
- Genomic and Immunotherapy Medical Institute, Dijon University Hospital, Dijon, Bourgogne-Franche-Comté, France
- University of Burgundy-Franche Comté, Dijon, Bourgogne-Franche-Comté, France
| | - Francois Ghiringhelli
- Platform of Transfer in Biological Oncology, Georges-Francois Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
- UMR INSERM 1231, Dijon, Bourgogne-Franche-Comté, France
- Genomic and Immunotherapy Medical Institute, Dijon University Hospital, Dijon, Bourgogne-Franche-Comté, France
- University of Burgundy-Franche Comté, Dijon, Bourgogne-Franche-Comté, France
- Departmnt of Medical Oncology, Georges François Leclerc Cancer Center - UNICANCER, Dijon, Bourgogne-Franche-Comté, France
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71
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Creamer KM, Larsen EC, Lawrence JB. ZNF146/OZF and ZNF507 target LINE-1 sequences. G3 (BETHESDA, MD.) 2022; 12:jkac002. [PMID: 35100360 PMCID: PMC8896011 DOI: 10.1093/g3journal/jkac002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Repetitive sequences including transposable elements and transposon-derived fragments account for nearly half of the human genome. While transposition-competent transposable elements must be repressed to maintain genomic stability, mutated and fragmented transposable elements comprising the bulk of repetitive sequences can also contribute to regulation of host gene expression and broader genome organization. Here, we analyzed published ChIP-seq data sets to identify proteins broadly enriched on transposable elements in the human genome. We show 2 of the proteins identified, C2H2 zinc finger-containing proteins ZNF146 (also known as OZF) and ZNF507, are targeted to distinct sites within LINE-1 ORF2 at thousands of locations in the genome. ZNF146 binding sites are found at old and young LINE-1 elements. In contrast, ZNF507 preferentially binds at young LINE-1 sequences correlated to sequence changes in LINE-1 elements at ZNF507's binding site. To gain further insight into ZNF146 and ZNF507 function, we disrupt their expression in HEK293 cells using CRISPR/Cas9 and perform RNA sequencing, finding modest gene expression changes in cells where ZNF507 has been disrupted. We further identify a physical interaction between ZNF507 and PRMT5, suggesting ZNF507 may target arginine methylation activity to LINE-1 sequences.
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Affiliation(s)
- Kevin M Creamer
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Eric C Larsen
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Jeanne B Lawrence
- Department of Neurology and Pediatrics, University of Massachusetts Medical School, Worcester, MA 01655, USA
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72
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Carter T, Singh M, Dumbovic G, Chobirko JD, Rinn JL, Feschotte C. Mosaic cis-regulatory evolution drives transcriptional partitioning of HERVH endogenous retrovirus in the human embryo. eLife 2022; 11:76257. [PMID: 35179489 PMCID: PMC8912925 DOI: 10.7554/elife.76257] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/17/2022] [Indexed: 12/05/2022] Open
Abstract
The human endogenous retrovirus type-H (HERVH) family is expressed in the preimplantation embryo. A subset of these elements are specifically transcribed in pluripotent stem cells where they appear to exert regulatory activities promoting self-renewal and pluripotency. How HERVH elements achieve such transcriptional specificity remains poorly understood. To uncover the sequence features underlying HERVH transcriptional activity, we performed a phyloregulatory analysis of the long terminal repeats (LTR7) of the HERVH family, which harbor its promoter, using a wealth of regulatory genomics data. We found that the family includes at least eight previously unrecognized subfamilies that have been active at different timepoints in primate evolution and display distinct expression patterns during human embryonic development. Notably, nearly all HERVH elements transcribed in ESCs belong to one of the youngest subfamilies we dubbed LTR7up. LTR7 sequence evolution was driven by a mixture of mutational processes, including point mutations, duplications, and multiple recombination events between subfamilies, that led to transcription factor binding motif modules characteristic of each subfamily. Using a reporter assay, we show that one such motif, a predicted SOX2/3 binding site unique to LTR7up, is essential for robust promoter activity in induced pluripotent stem cells. Together these findings illuminate the mechanisms by which HERVH diversified its expression pattern during evolution to colonize distinct cellular niches within the human embryo.
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Affiliation(s)
- Thomas Carter
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States [US]
| | - Manvendra Singh
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Gabrijela Dumbovic
- Department of Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Jason D Chobirko
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - John L Rinn
- Department of Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
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73
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Taubenschmid-Stowers J, Rostovskaya M, Santos F, Ljung S, Argelaguet R, Krueger F, Nichols J, Reik W. 8C-like cells capture the human zygotic genome activation program in vitro. Cell Stem Cell 2022; 29:449-459.e6. [PMID: 35216671 PMCID: PMC8901440 DOI: 10.1016/j.stem.2022.01.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/26/2021] [Accepted: 01/28/2022] [Indexed: 01/12/2023]
Abstract
The activation of the embryonic genome marks the first major wave of transcription in the developing organism. Zygotic genome activation (ZGA) in mouse 2-cell embryos and 8-cell embryos in humans is crucial for development. Here, we report the discovery of human 8-cell-like cells (8CLCs) among naive embryonic stem cells, which transcriptionally resemble the 8-cell human embryo. They express ZGA markers, including ZSCAN4 and LEUTX, and transposable elements, such as HERVL and MLT2A1. 8CLCs show reduced SOX2 levels and can be identified using TPRX1 and H3.Y marker proteins in vitro. Overexpression of the transcription factor DUX4 and spliceosome inhibition increase human ZGA-like transcription. Excitingly, the 8CLC markers TPRX1 and H3.Y are also expressed in ZGA-stage 8-cell human embryos and may thus be relevant in vivo. 8CLCs provide a unique opportunity to characterize human ZGA-like transcription and might provide critical insights into early events in embryogenesis in humans. ZGA genes and transposable elements are expressed in 8CLCs but not in naive stem cells DUX4 overexpression and spliceosome inhibition induce ZGA-like transcription 8CLC marker proteins TPRX1 and H3.Y are expressed in 8-cell human embryos 8CLCs can be used to study human ZGA-like programs in vitro
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Affiliation(s)
| | | | - Fátima Santos
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK; Centre for Trophoblast Research, University of Cambridge, Cambridge CB2 3EG, UK
| | - Sebastian Ljung
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | | | - Felix Krueger
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | - Jennifer Nichols
- Centre for Trophoblast Research, University of Cambridge, Cambridge CB2 3EG, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EL, UK
| | - Wolf Reik
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK; Centre for Trophoblast Research, University of Cambridge, Cambridge CB2 3EG, UK; Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK.
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74
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Pradhan RK, Ramakrishna W. Transposons: Unexpected players in cancer. Gene 2022; 808:145975. [PMID: 34592349 DOI: 10.1016/j.gene.2021.145975] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/19/2021] [Accepted: 09/24/2021] [Indexed: 12/21/2022]
Abstract
Transposons are repetitive DNA sequences encompassing about half of the human genome. They play a vital role in genome stability maintenance and contribute to genomic diversity and evolution. Their activity is regulated by various mechanisms considering the deleterious effects of these mobile elements. Various genetic risk factors and environmental stress conditions affect the regulatory pathways causing alteration of transposon expression. Our knowledge of the biological role of transposons is limited especially in various types of cancers. Retrotransposons of different types (LTR-retrotransposons, LINEs and SINEs) regulate a plethora of genes that have a role in cell reprogramming, tumor suppression, cell cycle, apoptosis, cell adhesion and migration, and DNA repair. The regulatory mechanisms of transposons, their deregulation and different mechanisms underlying transposon-mediated carcinogenesis in humans focusing on the three most prevalent types, lung, breast and colorectal cancers, were reviewed. The modes of regulation employed include alternative splicing, deletion, insertion, duplication in genes and promoters resulting in upregulation, downregulation or silencing of genes.
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75
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Abstract
The development of therapies to eliminate the latent HIV-1 reservoir is hampered by our incomplete understanding of the biomolecular mechanism governing HIV-1 latency. To further complicate matters, recent single cell RNA-seq studies reported extensive heterogeneity between latently HIV-1-infected primary T cells, implying that latent HIV-1 infection can persist in greatly differing host cell environments. We here show that transcriptomic heterogeneity is also found between latently infected T cell lines, which allowed us to study the underlying mechanisms of intercell heterogeneity at high signal resolution. Latently infected T cells exhibited a de-differentiated phenotype, characterized by the loss of T cell-specific markers and gene regulation profiles reminiscent of hematopoietic stem cells (HSC). These changes had functional consequences. As reported for stem cells, latently HIV-1 infected T cells efficiently forced lentiviral superinfections into a latent state and favored glycolysis. As a result, metabolic reprogramming or cell re-differentiation destabilized latent infection. Guided by these findings, data-mining of single cell RNA-seq data of latently HIV-1 infected primary T cells from patients revealed the presence of similar dedifferentiation motifs. >20% of the highly detectable genes that were differentially regulated in latently infected cells were associated with hematopoietic lineage development (e.g. HUWE1, IRF4, PRDM1, BATF3, TOX, ID2, IKZF3, CDK6) or were hematopoietic markers (SRGN; hematopoietic proteoglycan core protein). The data add to evidence that the biomolecular phenotype of latently HIV-1 infected cells differs from normal T cells and strategies to address their differential phenotype need to be considered in the design of therapeutic cure interventions. IMPORTANCE HIV-1 persists in a latent reservoir in memory CD4 T cells for the lifetime of a patient. Understanding the biomolecular mechanisms used by the host cells to suppress viral expression will provide essential insights required to develop curative therapeutic interventions. Unfortunately, our current understanding of these control mechanisms is still limited. By studying gene expression profiles, we demonstrated that latently HIV-1-infected T cells have a de-differentiated T cell phenotype. Software-based data integration allowed for the identification of drug targets that would re-differentiate viral host cells and, in extension, destabilize latent HIV-1 infection events. The importance of the presented data lies within the clear demonstration that HIV-1 latency is a host cell phenomenon. As such, therapeutic strategies must first restore proper host cell functionality to accomplish efficient HIV-1 reactivation.
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76
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Zhang Y, Ding H, Wang X, Wang X, Wan S, Xu A, Gan R, Ye SD. MK2 promotes Tfcp2l1 degradation via β-TrCP ubiquitin ligase to regulate mouse embryonic stem cell self-renewal. Cell Rep 2021; 37:109949. [PMID: 34731635 DOI: 10.1016/j.celrep.2021.109949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 08/31/2021] [Accepted: 10/14/2021] [Indexed: 10/19/2022] Open
Abstract
Tfcp2l1 can maintain mouse embryonic stem cell (mESC) self-renewal. However, it remains unknown how Tfcp2l1 protein stability is regulated. Here, we demonstrate that β-transducin repeat-containing protein (β-TrCP) targets Tfcp2l1 for ubiquitination and degradation in a mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MK2)-dependent manner. Specifically, β-TrCP1 and β-TrCP2 recognize and ubiquitylate Tfcp2l1 through the canonical β-TrCP-binding motif DSGDNS, in which the serine residues have been phosphorylated by MK2. Point mutation of serine-to-alanine residues reduces β-TrCP-mediated ubiquitylation and enhances the ability of Tfcp2l1 to promote mESC self-renewal while repressing the speciation of the endoderm, mesoderm, and trophectoderm. Similarly, inhibition of MK2 reduces the association of Tfcp2l1 with β-TrCP1 and increases the self-renewal-promoting effects of Tfcp2l1, whereas overexpression of MK2 or β-TrCP genes decreases Tfcp2l1 protein levels and induces mESC differentiation. Collectively, our study reveals a posttranslational modification of Tfcp2l1 that will expand our understanding of the regulatory network of stem cell pluripotency.
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Affiliation(s)
- Yan Zhang
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui 230601, China
| | - Huiwen Ding
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui 230601, China
| | - Xiaoxiao Wang
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Xin Wang
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui 230601, China
| | - Shengpeng Wan
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui 230601, China
| | - Anchun Xu
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui 230601, China
| | - Ruoyi Gan
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui 230601, China
| | - Shou-Dong Ye
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, Hefei, Anhui 230601, China; Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China.
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77
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Mao J, Zhang Q, Cong YS. Human endogenous retroviruses in development and disease. Comput Struct Biotechnol J 2021; 19:5978-5986. [PMID: 34849202 PMCID: PMC8604659 DOI: 10.1016/j.csbj.2021.10.037] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs) represent ∼8% of human genome, deriving from exogenous retroviral infections of germ line cells occurred millions of years ago and being inherited by the offspring in a Mendelian fashion. Most of HERVs are nonprotein-coding because of the accumulation of mutations, insertions, deletions, and/or truncations. It has been long thought that HERVs were "junk DNA". However, it is now known that HERVs are involved in various biological processes through encoding proteins, acting as promoters/enhancers, or lncRNAs to affect human health and disease. In this review, we summarized recent findings about HERVs, with implications in embryonic development, pluripotency, cancer, aging, and neurodegenerative diseases.
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Affiliation(s)
- Jian Mao
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University School of Basic Medical Sciences, Hangzhou, China
| | - Qian Zhang
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University School of Basic Medical Sciences, Hangzhou, China
| | - Yu-Sheng Cong
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University School of Basic Medical Sciences, Hangzhou, China
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78
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Senft AD, Macfarlan TS. Transposable elements shape the evolution of mammalian development. Nat Rev Genet 2021; 22:691-711. [PMID: 34354263 DOI: 10.1038/s41576-021-00385-1] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2021] [Indexed: 02/06/2023]
Abstract
Transposable elements (TEs) promote genetic innovation but also threaten genome stability. Despite multiple layers of host defence, TEs actively shape mammalian-specific developmental processes, particularly during pre-implantation and extra-embryonic development and at the maternal-fetal interface. Here, we review how TEs influence mammalian genomes both directly by providing the raw material for genetic change and indirectly via co-evolving TE-binding Krüppel-associated box zinc finger proteins (KRAB-ZFPs). Throughout mammalian evolution, individual activities of ancient TEs were co-opted to enable invasive placentation that characterizes live-born mammals. By contrast, the widespread activity of evolutionarily young TEs may reflect an ongoing co-evolution that continues to impact mammalian development.
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Affiliation(s)
- Anna D Senft
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, MD, USA.
| | - Todd S Macfarlan
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, MD, USA.
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79
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Upregulation of Human Endogenous Retroviruses in Bronchoalveolar Lavage Fluid of COVID-19 Patients. Microbiol Spectr 2021; 9:e0126021. [PMID: 34612698 PMCID: PMC8510252 DOI: 10.1128/spectrum.01260-21] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Severe COVID-19 pneumonia has been associated with the development of intense inflammatory responses during the course of infections with SARS-CoV-2. Given that human endogenous retroviruses (HERVs) are known to be activated during and participate in inflammatory processes, we examined whether HERV dysregulation signatures are present in COVID-19 patients. By comparing transcriptomes of bronchoalveolar lavage fluid (BALF) of COVID-19 patients and healthy controls, and peripheral blood monocytes (PBMCs) from patients and controls, we have shown that HERVs are intensely dysregulated in BALF of COVID-19 patients compared to those in BALF of healthy control patients but not in PBMCs. In particular, upregulation in the expression of specific HERV families was detected in BALF samples of COVID-19 patients, with HERV-FRD being the most highly upregulated family among the families analyzed. In addition, we compared the expression of HERVs in human bronchial epithelial cells (HBECs) without and after senescence induction in an oncogene-induced senescence model in order to quantitatively measure changes in the expression of HERVs in bronchial cells during the process of cellular senescence. This apparent difference of HERV dysregulation between PBMCs and BALF warrants further studies in the involvement of HERVs in inflammatory pathogenetic mechanisms as well as exploration of HERVs as potential biomarkers for disease progression. Furthermore, the increase in the expression of HERVs in senescent HBECs in comparison to that in noninduced HBECs provides a potential link for increased COVID-19 severity and mortality in aged populations. IMPORTANCE SARS-CoV-2 emerged in late 2019 in China, causing a global pandemic. Severe COVID-19 is characterized by intensive inflammatory responses, and older age is an important risk factor for unfavorable outcomes. HERVs are remnants of ancient infections whose expression is upregulated in multiple conditions, including cancer and inflammation, and their expression is increased with increasing age. The significance of this work is that we were able to recognize dysregulated expression of endogenous retroviral elements in BALF samples but not in PBMCs of COVID-19 patients. At the same time, we were able to identify upregulated expression of multiple HERV families in senescence-induced HBECs in comparison to that in noninduced HBECs, a fact that could possibly explain the differences in disease severity among age groups. These results indicate that HERV expression might play a pathophysiological role in local inflammatory pathways in lungs afflicted by SARS-CoV-2 and their expression could be a potential therapeutic target.
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80
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Affiliation(s)
- Seungbok Yang
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Yoonjae Cho
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Jiwon Jang
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
- Institute of Convergence Science, Yonsei University, Seoul 03722, Korea
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81
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Dittmar T, Weiler J, Luo T, Hass R. Cell-Cell Fusion Mediated by Viruses and HERV-Derived Fusogens in Cancer Initiation and Progression. Cancers (Basel) 2021; 13:5363. [PMID: 34771528 PMCID: PMC8582398 DOI: 10.3390/cancers13215363] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/22/2021] [Accepted: 10/24/2021] [Indexed: 12/13/2022] Open
Abstract
Cell fusion is a well-known, but still scarcely understood biological phenomenon, which might play a role in cancer initiation, progression and formation of metastases. Although the merging of two (cancer) cells appears simple, the entire process is highly complex, energy-dependent and tightly regulated. Among cell fusion-inducing and -regulating factors, so-called fusogens have been identified as a specific type of proteins that are indispensable for overcoming fusion-associated energetic barriers and final merging of plasma membranes. About 8% of the human genome is of retroviral origin and some well-known fusogens, such as syncytin-1, are expressed by human (cancer) cells. Likewise, enveloped viruses can enable and facilitate cell fusion due to evolutionarily optimized fusogens, and are also capable to induce bi- and multinucleation underlining their fusion capacity. Moreover, multinucleated giant cancer cells have been found in tumors derived from oncogenic viruses. Accordingly, a potential correlation between viruses and fusogens of human endogenous retroviral origin in cancer cell fusion will be summarized in this review.
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Affiliation(s)
- Thomas Dittmar
- Institute of Immunology, Center for Biomedical Education and Research (ZBAF), Witten/Herdecke University, 58448 Witten, Germany;
| | - Julian Weiler
- Institute of Immunology, Center for Biomedical Education and Research (ZBAF), Witten/Herdecke University, 58448 Witten, Germany;
| | - Tianjiao Luo
- Biochemistry and Tumor Biology Laboratory, Department of Obstetrics and Gynecology, Hannover Medical School, 30625 Hannover, Germany;
| | - Ralf Hass
- Biochemistry and Tumor Biology Laboratory, Department of Obstetrics and Gynecology, Hannover Medical School, 30625 Hannover, Germany;
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82
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Hsieh FK, Ji F, Damle M, Sadreyev RI, Kingston RE. HERVH-derived lncRNAs negatively regulate chromatin targeting and remodeling mediated by CHD7. Life Sci Alliance 2021; 5:5/1/e202101127. [PMID: 34663690 PMCID: PMC8548210 DOI: 10.26508/lsa.202101127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/13/2022] Open
Abstract
Mutations in CHD7 are diagnostic for human CHARGE syndrome. RNAs expressed from the HERVH repeats modulate CHD7 function providing one mechanism for regulation of differentiation of pluripotent cells. Chd7 encodes an ATP-dependent chromatin remodeler which has been shown to target specific genomic loci and alter local transcription potentially by remodeling chromatin structure. De novo mutations in CHD7 are the major cause of CHARGE syndrome which features multiple developmental defects. We examined whether nuclear RNAs might contribute to its targeting and function and identified a preferential interaction between CHD7 and lncRNAs derived from HERVH loci in pluripotent stem cells. Knockdown of HERVH family lncRNAs using LNAs or knockout of an individual copy of HERVH by CRISPR-Cas9 both resulted in increased binding of CHD7 and increased levels of H3K27ac at a subset of enhancers. Depletion of HERVH family RNAs led to the activation of multiple genes. CHD7 bound HERVH RNA with high affinity but low specificity and this interaction decreased the ability of CHD7 to bind and remodel nucleosomes. We present a model in which HERVH lncRNAs act as a decoy to modulate the dynamics of CHD7 binding to enhancers in pluripotent cells and the activation of numerous genes that might impact the differentiation process.
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Affiliation(s)
- Fu-Kai Hsieh
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Fei Ji
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Manashree Damle
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Ruslan I Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Robert E Kingston
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA .,Department of Genetics, Harvard Medical School, Boston, MA, USA
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83
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Duan K, Si CY, Zhao SM, Ai ZY, Niu BH, Yin Y, Xiang LF, Ding H, Zheng Y. The Long Terminal Repeats of ERV6 Are Activated in Pre-Implantation Embryos of Cynomolgus Monkey. Cells 2021; 10:cells10102710. [PMID: 34685690 PMCID: PMC8534818 DOI: 10.3390/cells10102710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/28/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022] Open
Abstract
Precise gene regulation is critical during embryo development. Long terminal repeat elements (LTRs) of endogenous retroviruses (ERVs) are dynamically expressed in blastocysts of mammalian embryos. However, the expression pattern of LTRs in monkey blastocyst is still unknown. By single-cell RNA-sequencing (seq) data of cynomolgus monkeys, we found that LTRs of several ERV families, including MacERV6, MacERV3, MacERV2, MacERVK1, and MacERVK2, were highly expressed in pre-implantation embryo cells including epiblast (EPI), trophectoderm (TrB), and primitive endoderm (PrE), but were depleted in post-implantation. We knocked down MacERV6-LTR1a in cynomolgus monkeys with a short hairpin RNA (shRNA) strategy to examine the potential function of MacERV6-LTR1a in the early development of monkey embryos. The silence of MacERV6-LTR1a mainly postpones the differentiation of TrB, EPI, and PrE cells in embryos at day 7 compared to control. Moreover, we confirmed MacERV6-LTR1a could recruit Estrogen Related Receptor Beta (ESRRB), which plays an important role in the maintenance of self-renewal and pluripotency of embryonic and trophoblast stem cells through different signaling pathways including FGF and Wnt signaling pathways. In summary, these results suggest that MacERV6-LTR1a is involved in gene regulation of the pre-implantation embryo of the cynomolgus monkeys.
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Affiliation(s)
- Kui Duan
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Chen-Yang Si
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Shu-Mei Zhao
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Zong-Yong Ai
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Bao-Hua Niu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Yu Yin
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Li-Feng Xiang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Hao Ding
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
| | - Yun Zheng
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (K.D.); (C.-Y.S.); (S.-M.Z.); (Z.-Y.A.); (B.-H.N.); (Y.Y.); (L.-F.X.); (H.D.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming University of Science and Technology, Kunming 650500, China
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Provincial Academy of Science and Technology, Kunming 650500, China
- Correspondence:
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84
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Endogenous reverse transcriptase and RNase H-mediated antiviral mechanism in embryonic stem cells. Cell Res 2021; 31:998-1010. [PMID: 34158624 PMCID: PMC8217788 DOI: 10.1038/s41422-021-00524-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 05/26/2021] [Indexed: 02/06/2023] Open
Abstract
Nucleic acid-based systems play important roles in antiviral defense, including CRISPR/Cas that adopts RNA-guided DNA cleavage to prevent DNA phage infection and RNA interference (RNAi) that employs RNA-guided RNA cleavage to defend against RNA virus infection. Here, we report a novel type of nucleic acid-based antiviral system that exists in mouse embryonic stem cells (mESCs), which suppresses RNA virus infection by DNA-mediated RNA cleavage. We found that the viral RNA of encephalomyocarditis virus can be reverse transcribed into complementary DNA (vcDNA) by the reverse transcriptase (RTase) encoded by endogenous retrovirus-like elements in mESCs. The vcDNA is negative-sense single-stranded and forms DNA/RNA hybrid with viral RNA. The viral RNA in the heteroduplex is subsequently destroyed by cellular RNase H1, leading to robust suppression of viral growth. Furthermore, either inhibition of the RTase activity or depletion of endogenous RNase H1 results in the promotion of virus proliferation. Altogether, our results provide intriguing insights into the antiviral mechanism of mESCs and the antiviral function of endogenized retroviruses and cellular RNase H. Such a natural nucleic acid-based antiviral mechanism in mESCs is referred to as ERASE (endogenous RTase/RNase H-mediated antiviral system), which is an addition to the previously known nucleic acid-based antiviral mechanisms including CRISPR/Cas in bacteria and RNAi in plants and invertebrates.
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85
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Babarinde IA, Ma G, Li Y, Deng B, Luo Z, Liu H, Abdul MM, Ward C, Chen M, Fu X, Shi L, Duttlinger M, He J, Sun L, Li W, Zhuang Q, Tong G, Frampton J, Cazier JB, Chen J, Jauch R, Esteban MA, Hutchins AP. Transposable element sequence fragments incorporated into coding and noncoding transcripts modulate the transcriptome of human pluripotent stem cells. Nucleic Acids Res 2021; 49:9132-9153. [PMID: 34390351 PMCID: PMC8450112 DOI: 10.1093/nar/gkab710] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 12/12/2022] Open
Abstract
Transposable elements (TEs) occupy nearly 40% of mammalian genomes and, whilst most are fragmentary and no longer capable of transposition, they can nevertheless contribute to cell function. TEs within genes transcribed by RNA polymerase II can be copied as parts of primary transcripts; however, their full contribution to mature transcript sequences remains unresolved. Here, using long and short read (LR and SR) RNA sequencing data, we show that 26% of coding and 65% of noncoding transcripts in human pluripotent stem cells (hPSCs) contain TE-derived sequences. Different TE families are incorporated into RNAs in unique patterns, with consequences to transcript structure and function. The presence of TE sequences within a transcript is correlated with TE-type specific changes in its subcellular distribution, alterations in steady-state levels and half-life, and differential association with RNA Binding Proteins (RBPs). We identify hPSC-specific incorporation of endogenous retroviruses (ERVs) and LINE:L1 into protein-coding mRNAs, which generate TE sequence-derived peptides. Finally, single cell RNA-seq reveals that hPSCs express ERV-containing transcripts, whilst differentiating subpopulations lack ERVs and express SINE and LINE-containing transcripts. Overall, our comprehensive analysis demonstrates that the incorporation of TE sequences into the RNAs of hPSCs is more widespread and has a greater impact than previously appreciated.
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Affiliation(s)
- Isaac A Babarinde
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Gang Ma
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuhao Li
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Boping Deng
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Zhiwei Luo
- Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Hao Liu
- Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Mazid Md Abdul
- Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Carl Ward
- Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Minchun Chen
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xiuling Fu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Liyang Shi
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Martha Duttlinger
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jiangping He
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China
| | - Li Sun
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenjuan Li
- Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Qiang Zhuang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Guoqing Tong
- Center for Reproductive Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200120, China
| | - Jon Frampton
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Jean-Baptiste Cazier
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK.,Centre for Computational Biology, University of Birmingham, Birmingham, UK
| | - Jiekai Chen
- Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China.,Joint School of Life Sciences, Guangzhou Medical University and Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Ralf Jauch
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Miguel A Esteban
- Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China
| | - Andrew P Hutchins
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
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86
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Hermant C, Torres-Padilla ME. TFs for TEs: the transcription factor repertoire of mammalian transposable elements. Genes Dev 2021; 35:22-39. [PMID: 33397727 PMCID: PMC7778262 DOI: 10.1101/gad.344473.120] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this review, Hermant and Torres-Padilla summarize and discuss the transcription factors known to be involved in the sequence-specific recognition and transcriptional activation of specific transposable element families or subfamilies. Transposable elements (TEs) are genetic elements capable of changing position within the genome. Although their mobilization can constitute a threat to genome integrity, nearly half of modern mammalian genomes are composed of remnants of TE insertions. The first critical step for a successful transposition cycle is the generation of a full-length transcript. TEs have evolved cis-regulatory elements enabling them to recruit host-encoded factors driving their own, selfish transcription. TEs are generally transcriptionally silenced in somatic cells, and the mechanisms underlying their repression have been extensively studied. However, during germline formation, preimplantation development, and tumorigenesis, specific TE families are highly expressed. Understanding the molecular players at stake in these contexts is of utmost importance to establish the mechanisms regulating TEs, as well as the importance of their transcription to the biology of the host. Here, we review the transcription factors known to be involved in the sequence-specific recognition and transcriptional activation of specific TE families or subfamilies. We discuss the diversity of TE regulatory elements within mammalian genomes and highlight the importance of TE mobilization in the dispersal of transcription factor-binding sites over the course of evolution.
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Affiliation(s)
- Clara Hermant
- Institute of Epigenetics and Stem Cells (IES), Helmholtz Zentrum München, D-81377 München, Germany
| | - Maria-Elena Torres-Padilla
- Institute of Epigenetics and Stem Cells (IES), Helmholtz Zentrum München, D-81377 München, Germany.,Faculty of Biology, Ludwig-Maximilians Universität München, D-82152 Planegg-Martinsried, Germany
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87
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Liu Y, He J, Chen R, Liu H, Chen J, Liu Y, Wang B, Guo L, Pei D, Wang J, Liu J, Chen J. AP-1 activity is a major barrier of human somatic cell reprogramming. Cell Mol Life Sci 2021; 78:5847-5863. [PMID: 34181046 PMCID: PMC11072308 DOI: 10.1007/s00018-021-03883-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: 10/09/2020] [Revised: 05/09/2021] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
Human induced pluripotent stem cells (iPSCs) technology has been widely applied to cell regeneration and disease modeling. However, most mechanism of somatic reprogramming is studied on mouse system, which is not always generic in human. Consequently, the generation of human iPSCs remains inefficient. Here, we map the chromatin accessibility dynamics during the induction of human iPSCs from urine cells. Comparing to the mouse system, we found that the closing of somatic loci is much slower in human. Moreover, a conserved AP-1 motif is highly enriched among the closed loci. The introduction of AP-1 repressor, JDP2, enhances human reprogramming and facilitates the reactivation of pluripotent genes. However, ESRRB, KDM2B and SALL4, several known pluripotent factors promoting mouse somatic reprogramming fail to enhance human iPSC generation. Mechanistically, we reveal that JDP2 promotes the closing of somatic loci enriching AP-1 motifs to enhance human reprogramming. Furthermore, JDP2 can rescue reprogramming deficiency without MYC or KLF4. These results indicate AP-1 activity is a major barrier to prevent chromatin remodeling during somatic cell reprogramming.
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Affiliation(s)
- Yuting Liu
- CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Jiangping He
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory, Guangzhou Regenerative Medicine and Health GuangDong Laboratory , Guangzhou, 510005, China
| | - Ruhai Chen
- Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 511436, China
| | - He Liu
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory, Guangzhou Regenerative Medicine and Health GuangDong Laboratory , Guangzhou, 510005, China
| | - Jocelyn Chen
- The Loomis Chaffee School, Windsor, CT, 06095, USA
| | - Yujian Liu
- CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Bo Wang
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory, Guangzhou Regenerative Medicine and Health GuangDong Laboratory , Guangzhou, 510005, China
| | - Lin Guo
- CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory, Guangzhou Regenerative Medicine and Health GuangDong Laboratory , Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Duanqing Pei
- CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 511436, China
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory, Guangzhou Regenerative Medicine and Health GuangDong Laboratory , Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Jie Wang
- CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Jing Liu
- CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory, Guangzhou Regenerative Medicine and Health GuangDong Laboratory , Guangzhou, 510005, China.
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
| | - Jiekai Chen
- CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 511436, China.
- Center for Cell Lineage and Atlas (CCLA), Bioland Laboratory, Guangzhou Regenerative Medicine and Health GuangDong Laboratory , Guangzhou, 510005, China.
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
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88
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Sexton CE, Tillett RL, Han MV. The essential but enigmatic regulatory role of HERVH in pluripotency. Trends Genet 2021; 38:12-21. [PMID: 34340871 DOI: 10.1016/j.tig.2021.07.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 01/09/2023]
Abstract
Human specific endogenous retrovirus H (HERVH) is highly expressed in both naive and primed stem cells and is essential for pluripotency. Despite the proven relationship between HERVH expression and pluripotency, there is no single definitive model for the function of HERVH. Instead, several hypotheses of a regulatory function have been put forward including HERVH acting as enhancers, long noncoding RNAs (lncRNAs), and most recently as markers of topologically associating domain (TAD) boundaries. Recently several enhancer-associated lncRNAs have been characterized, which bind to Mediator and are necessary for promoter-enhancer folding interactions. We propose a synergistic model of HERVH function combining relevant findings and discuss the current limitations for its role in regulation, including the lack of evidence for a pluripotency-associated target gene.
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Affiliation(s)
- Corinne E Sexton
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154, USA
| | | | - Mira V Han
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154, USA; Nevada Institute of Personalized Medicine, Las Vegas, NV 89154, USA.
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89
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Lu P, Li M, Zhang D, Jiang W. Lnc-ing pluripotency maintenance and early differentiation in human pluripotent stem cells. FASEB J 2021; 35:e21438. [PMID: 33749897 DOI: 10.1096/fj.202002278r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/28/2020] [Accepted: 01/29/2021] [Indexed: 01/17/2023]
Abstract
Pluripotency maintenance and lineage differentiation are two major characteristics of human embryonic and induced pluripotent stem cells. The determination of self-renewal or differentiation is under the exquisite control of the gene regulatory network, which is composed of transcription factors, signaling pathways, metabolic factors, chromatin or histone modifiers, miRNAs, and lncRNAs. Growing evidence has shown that long noncoding RNAs (lncRNAs) play important roles in epigenetic, transcriptional, and posttranscriptional gene regulation during the cell fate determination of pluripotent stem cells. Here, we summarize recent reports of lncRNA functions in pluripotency maintenance/exit and the early germ layer specification of human pluripotent stem cells. We also illustrate four major lncRNA functional mechanisms according to different types of cofactors: chromatin or histone modifiers, transcription factors, canonical and noncanonical RNA-binding proteins, and miRNAs. Further understanding of lncRNA-based regulation will provide more insights into the drivers manipulating cell fate and promote the therapeutic and research potential of human embryonic and induced pluripotent stem cells.
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Affiliation(s)
- Pei Lu
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Mao Li
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Donghui Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, China
| | - Wei Jiang
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China.,Human Genetics Resource Preservation Center of Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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90
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Yedavalli VRK, Patil A, Parrish J, Kozak CA. A novel class III endogenous retrovirus with a class I envelope gene in African frogs with an intact genome and developmentally regulated transcripts in Xenopus tropicalis. Retrovirology 2021; 18:20. [PMID: 34261506 PMCID: PMC8278194 DOI: 10.1186/s12977-021-00564-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/29/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Retroviruses exist as exogenous infectious agents and as endogenous retroviruses (ERVs) integrated into host chromosomes. Such endogenous retroviruses (ERVs) are grouped into three classes roughly corresponding to the seven genera of infectious retroviruses: class I (gamma-, epsilonretroviruses), class II (alpha-, beta-, delta-, lentiretroviruses) and class III (spumaretroviruses). Some ERVs have counterparts among the known infectious retroviruses, while others represent paleovirological relics of extinct or undiscovered retroviruses. RESULTS Here we identify an intact ERV in the Anuran amphibian, Xenopus tropicalis. XtERV-S has open reading frames (ORFs) for gag, pol (polymerase) and env (envelope) genes, with a small additional ORF in pol and a serine tRNA primer binding site. It has unusual features and domain relationships to known retroviruses. Analyses based on phylogeny and functional motifs establish that XtERV-S gag and pol genes are related to the ancient env-less class III ERV-L family but the surface subunit of env is unrelated to known retroviruses while its transmembrane subunit is class I-like. LTR constructs show transcriptional activity, and XtERV-S transcripts are detected in embryos after the maternal to zygotic mid-blastula transition and before the late tailbud stage. Tagged Gag protein shows typical subcellular localization. The presence of ORFs in all three protein-coding regions along with identical 5' and 3' LTRs (long terminal repeats) indicate this is a very recent germline acquisition. There are older, full-length, nonorthologous, defective copies in Xenopus laevis and the distantly related African bullfrog, Pyxicephalus adspersus. Additional older, internally deleted copies in X. tropicalis carry a 300 bp LTR substitution. CONCLUSIONS XtERV-S represents a genera-spanning member of the largely env-less class III ERV that has ancient and modern copies in Anurans. This provirus has an env ORF with a surface subunit unrelated to known retroviruses and a transmembrane subunit related to class I gammaretroviruses in sequence and organization, and is expressed in early embryogenesis. Additional XtERV-S-related but defective copies are present in X. tropicalis and other African frog taxa. XtERV-S is an unusual class III ERV variant, and it may represent an important transitional retroviral form that has been spreading in African frogs for tens of millions of years.
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Affiliation(s)
- Venkat R K Yedavalli
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD, 20892, USA
| | - Akash Patil
- Department of Biomedical Engineering, John Hopkins University, Baltimore, MD, 21205, USA
| | - Janay Parrish
- Internal Medicine, Northwell Health, Lenox Hill Hospital, New York, NY, 10075, USA
| | - Christine A Kozak
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD, 20892, USA.
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91
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Global Transcriptional Analyses of the Wnt-Induced Development of Neural Stem Cells from Human Pluripotent Stem Cells. Int J Mol Sci 2021; 22:ijms22147473. [PMID: 34299091 PMCID: PMC8308016 DOI: 10.3390/ijms22147473] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/02/2021] [Accepted: 07/07/2021] [Indexed: 12/28/2022] Open
Abstract
The differentiation of human pluripotent stem cells (hPSCs) to neural stem cells (NSCs) is the key initial event in neurogenesis and is thought to be dependent on the family of Wnt growth factors, their receptors and signaling proteins. The delineation of the transcriptional pathways that mediate Wnt-induced hPSCs to NSCs differentiation is vital for understanding the global genomic mechanisms of the development of NSCs and, potentially, the creation of new protocols in regenerative medicine. To understand the genomic mechanism of Wnt signaling during NSCs development, we treated hPSCs with Wnt activator (CHIR-99021) and leukemia inhibitory factor (LIF) in a chemically defined medium (N2B27) to induce NSCs, referred to as CLNSCs. The CLNSCs were subcultured for more than 40 passages in vitro; were positive for AP staining; expressed neural progenitor markers such as NESTIN, PAX6, SOX2, and SOX1; and were able to differentiate into three neural lineage cells: neurons, astrocytes, and oligodendrocytes in vitro. Our transcriptome analyses revealed that the Wnt and Hedgehog signaling pathways regulate hPSCs cell fate decisions for neural lineages and maintain the self-renewal of CLNSCs. One interesting network could be the deregulation of the Wnt/β-catenin signaling pathway in CLNSCs via the downregulation of c-MYC, which may promote exit from pluripotency and neural differentiation. The Wnt-induced spinal markers HOXA1-4, HOXA7, HOXB1-4, and HOXC4 were increased, however, the brain markers FOXG1 and OTX2, were absent in the CLNSCs, indicating that CLNSCs have partial spinal cord properties. Finally, a CLNSC simple culture condition, when applied to hPSCs, supports the generation of NSCs, and provides a new and efficient cell model with which to untangle the mechanisms during neurogenesis.
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92
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Fu H, Zhang W, Li N, Yang J, Ye X, Tian C, Lu X, Liu L. Elevated retrotransposon activity and genomic instability in primed pluripotent stem cells. Genome Biol 2021; 22:201. [PMID: 34243810 PMCID: PMC8268579 DOI: 10.1186/s13059-021-02417-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/24/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Naïve and primed pluripotent stem cells (PSCs) represent two different pluripotent states. Primed PSCs following in vitro culture exhibit lower developmental potency as evidenced by failure in germline chimera assays, unlike mouse naïve PSCs. However, the molecular mechanisms underlying the lower developmental competency of primed PSCs remain elusive. RESULTS We examine the regulation of telomere maintenance, retrotransposon activity, and genomic stability of primed PSCs and compare them with naïve PSCs. Surprisingly, primed PSCs only minimally maintain telomeres and show fragile telomeres, associated with declined DNA recombination and repair activity, in contrast to naïve PSCs that robustly elongate telomeres. Also, we identify LINE1 family integrant L1Md_T as naïve-specific retrotransposon and ERVK family integrant IAPEz to define primed PSCs, and their transcription is differentially regulated by heterochromatic histones and Dnmt3b. Notably, genomic instability of primed PSCs is increased, in association with aberrant retrotransposon activity. CONCLUSIONS Our data suggest that fragile telomere, retrotransposon-associated genomic instability, and declined DNA recombination repair, together with reduced function of cell cycle and mitochondria, increased apoptosis, and differentiation properties may link to compromised developmental potency of primed PSCs, noticeably distinguishable from naïve PSCs.
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Affiliation(s)
- Haifeng Fu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
| | - Weiyu Zhang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
- College of Pharmacy, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Niannian Li
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
| | - Jiao Yang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaoying Ye
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
| | - Chenglei Tian
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
| | - Xinyi Lu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
- College of Pharmacy, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China.
- The Key Laboratory of Bioactive Materials Ministry of Education, Nankai University, Tianjin, China.
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93
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Almojil D, Bourgeois Y, Falis M, Hariyani I, Wilcox J, Boissinot S. The Structural, Functional and Evolutionary Impact of Transposable Elements in Eukaryotes. Genes (Basel) 2021; 12:genes12060918. [PMID: 34203645 PMCID: PMC8232201 DOI: 10.3390/genes12060918] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
Transposable elements (TEs) are nearly ubiquitous in eukaryotes. The increase in genomic data, as well as progress in genome annotation and molecular biology techniques, have revealed the vast number of ways mobile elements have impacted the evolution of eukaryotes. In addition to being the main cause of difference in haploid genome size, TEs have affected the overall organization of genomes by accumulating preferentially in some genomic regions, by causing structural rearrangements or by modifying the recombination rate. Although the vast majority of insertions is neutral or deleterious, TEs have been an important source of evolutionary novelties and have played a determinant role in the evolution of fundamental biological processes. TEs have been recruited in the regulation of host genes and are implicated in the evolution of regulatory networks. They have also served as a source of protein-coding sequences or even entire genes. The impact of TEs on eukaryotic evolution is only now being fully appreciated and the role they may play in a number of biological processes, such as speciation and adaptation, remains to be deciphered.
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Affiliation(s)
- Dareen Almojil
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi P.O. Box 129188, United Arab Emirates; (D.A.); (M.F.); (I.H.); (J.W.)
| | - Yann Bourgeois
- School of Biological Sciences, University of Portsmouth, Portsmouth, UK;
| | - Marcin Falis
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi P.O. Box 129188, United Arab Emirates; (D.A.); (M.F.); (I.H.); (J.W.)
| | - Imtiyaz Hariyani
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi P.O. Box 129188, United Arab Emirates; (D.A.); (M.F.); (I.H.); (J.W.)
| | - Justin Wilcox
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi P.O. Box 129188, United Arab Emirates; (D.A.); (M.F.); (I.H.); (J.W.)
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Saadiyat Island, Abu Dhabi P.O. Box 129188, United Arab Emirates
| | - Stéphane Boissinot
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi P.O. Box 129188, United Arab Emirates; (D.A.); (M.F.); (I.H.); (J.W.)
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Saadiyat Island, Abu Dhabi P.O. Box 129188, United Arab Emirates
- Correspondence:
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94
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Lu JY, Chang L, Li T, Wang T, Yin Y, Zhan G, Han X, Zhang K, Tao Y, Percharde M, Wang L, Peng Q, Yan P, Zhang H, Bi X, Shao W, Hong Y, Wu Z, Ma R, Wang P, Li W, Zhang J, Chang Z, Hou Y, Zhu B, Ramalho-Santos M, Li P, Xie W, Na J, Sun Y, Shen X. Homotypic clustering of L1 and B1/Alu repeats compartmentalizes the 3D genome. Cell Res 2021; 31:613-630. [PMID: 33514913 PMCID: PMC8169921 DOI: 10.1038/s41422-020-00466-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 12/17/2020] [Indexed: 01/30/2023] Open
Abstract
Organization of the genome into euchromatin and heterochromatin appears to be evolutionarily conserved and relatively stable during lineage differentiation. In an effort to unravel the basic principle underlying genome folding, here we focus on the genome itself and report a fundamental role for L1 (LINE1 or LINE-1) and B1/Alu retrotransposons, the most abundant subclasses of repetitive sequences, in chromatin compartmentalization. We find that homotypic clustering of L1 and B1/Alu demarcates the genome into grossly exclusive domains, and characterizes and predicts Hi-C compartments. Spatial segregation of L1-rich sequences in the nuclear and nucleolar peripheries and B1/Alu-rich sequences in the nuclear interior is conserved in mouse and human cells and occurs dynamically during the cell cycle. In addition, de novo establishment of L1 and B1 nuclear segregation is coincident with the formation of higher-order chromatin structures during early embryogenesis and appears to be critically regulated by L1 and B1 transcripts. Importantly, depletion of L1 transcripts in embryonic stem cells drastically weakens homotypic repeat contacts and compartmental strength, and disrupts the nuclear segregation of L1- or B1-rich chromosomal sequences at genome-wide and individual sites. Mechanistically, nuclear co-localization and liquid droplet formation of L1 repeat DNA and RNA with heterochromatin protein HP1α suggest a phase-separation mechanism by which L1 promotes heterochromatin compartmentalization. Taken together, we propose a genetically encoded model in which L1 and B1/Alu repeats blueprint chromatin macrostructure. Our model explains the robustness of genome folding into a common conserved core, on which dynamic gene regulation is overlaid across cells.
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Affiliation(s)
- J Yuyang Lu
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Lei Chang
- State Key Laboratory of Membrane Biology, Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, and College of Future Technology, Peking University, Beijing, 100871, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong, 510005, China
| | - Tong Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ting Wang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yafei Yin
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ge Zhan
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xue Han
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ke Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yibing Tao
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Michelle Percharde
- MRC London Institute of Medical Sciences (LMS), London, W120NN, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W120NN, UK
| | - Liang Wang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qi Peng
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Pixi Yan
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Hui Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xianju Bi
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wen Shao
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yantao Hong
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhongyang Wu
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Runze Ma
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Peizhe Wang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wenzhi Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jing Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zai Chang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yingping Hou
- State Key Laboratory of Membrane Biology, Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, and College of Future Technology, Peking University, Beijing, 100871, China
| | - Bing Zhu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Miguel Ramalho-Santos
- Lunenfeld-Tanenbaum Research Institute, University of Toronto, Toronto, Ontario, M5T 3H7, Canada
| | - Pilong Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wei Xie
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jie Na
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, and College of Future Technology, Peking University, Beijing, 100871, China.
| | - Xiaohua Shen
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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95
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Bello-Morales R, Andreu S, Ripa I, López-Guerrero JA. HSV-1 and Endogenous Retroviruses as Risk Factors in Demyelination. Int J Mol Sci 2021; 22:ijms22115738. [PMID: 34072259 PMCID: PMC8199333 DOI: 10.3390/ijms22115738] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/19/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) is a neurotropic alphaherpesvirus that can infect the peripheral and central nervous systems, and it has been implicated in demyelinating and neurodegenerative processes. Transposable elements (TEs) are DNA sequences that can move from one genomic location to another. TEs have been linked to several diseases affecting the central nervous system (CNS), including multiple sclerosis (MS), a demyelinating disease of unknown etiology influenced by genetic and environmental factors. Exogenous viral transactivators may activate certain retrotransposons or class I TEs. In this context, several herpesviruses have been linked to MS, and one of them, HSV-1, might act as a risk factor by mediating processes such as molecular mimicry, remyelination, and activity of endogenous retroviruses (ERVs). Several herpesviruses have been involved in the regulation of human ERVs (HERVs), and HSV-1 in particular can modulate HERVs in cells involved in MS pathogenesis. This review exposes current knowledge about the relationship between HSV-1 and human ERVs, focusing on their contribution as a risk factor for MS.
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Affiliation(s)
- Raquel Bello-Morales
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (S.A.); (I.R.); (J.A.L.-G.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, 28049 Madrid, Spain
- Correspondence:
| | - Sabina Andreu
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (S.A.); (I.R.); (J.A.L.-G.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, 28049 Madrid, Spain
| | - Inés Ripa
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (S.A.); (I.R.); (J.A.L.-G.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, 28049 Madrid, Spain
| | - José Antonio López-Guerrero
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (S.A.); (I.R.); (J.A.L.-G.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, 28049 Madrid, Spain
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96
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The pluripotent stem cell-specific transcript ESRG is dispensable for human pluripotency. PLoS Genet 2021; 17:e1009587. [PMID: 34033652 PMCID: PMC8184003 DOI: 10.1371/journal.pgen.1009587] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 06/07/2021] [Accepted: 05/06/2021] [Indexed: 12/29/2022] Open
Abstract
Human pluripotent stem cells (PSCs) express human endogenous retrovirus type-H (HERV-H), which exists as more than a thousand copies on the human genome and frequently produces chimeric transcripts as long-non-coding RNAs (lncRNAs) fused with downstream neighbor genes. Previous studies showed that HERV-H expression is required for the maintenance of PSC identity, and aberrant HERV-H expression attenuates neural differentiation potentials, however, little is known about the actual of function of HERV-H. In this study, we focused on ESRG, which is known as a PSC-related HERV-H-driven lncRNA. The global transcriptome data of various tissues and cell lines and quantitative expression analysis of PSCs showed that ESRG expression is much higher than other HERV-Hs and tightly silenced after differentiation. However, the loss of function by the complete excision of the entire ESRG gene body using a CRISPR/Cas9 platform revealed that ESRG is dispensable for the maintenance of the primed and naïve pluripotent states. The loss of ESRG hardly affected the global gene expression of PSCs or the differentiation potential toward trilineage. Differentiated cells derived from ESRG-deficient PSCs retained the potential to be reprogrammed into induced PSCs (iPSCs) by the forced expression of OCT3/4, SOX2, and KLF4. In conclusion, ESRG is dispensable for the maintenance and recapturing of human pluripotency. We have been interested in the role of human endogenous retrovirus (HERVs) in human pluripotent stem cells (PSCs). Although we and others have demonstrated that HERV expression is crucial for somatic cell reprogramming to a pluripotent state and the characteristics of PSCs. Little is known which one of more than 1,000 copies of HERVs is important. Thus, in this study, we focused on a HERV-related gene, ESRG which is expressed strongly and specifically in human PSCs but not in differentiated cells. Using a CRISPR/Cas9 platform, we generated complete knockout cell lines by deleting the entire gene body of ESRG. Our results demonstrate that ESRG is dispensable for the PSC characters such as gene expression, self-renewing capacity, and differentiation potential. In addition, ESRG does not contribute to the reprogramming of differentiated cells to a pluripotent state. Altogether, we concluded that ESRG is an excellent marker of pluripotency but dispensable for the PSC identity.
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97
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Jansz N, Faulkner GJ. Endogenous retroviruses in the origins and treatment of cancer. Genome Biol 2021; 22:147. [PMID: 33971937 PMCID: PMC8108463 DOI: 10.1186/s13059-021-02357-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/21/2021] [Indexed: 02/07/2023] Open
Abstract
Endogenous retroviruses (ERVs) are emerging as promising therapeutic targets in cancer. As remnants of ancient retroviral infections, ERV-derived regulatory elements coordinate expression from gene networks, including those underpinning embryogenesis and immune cell function. ERV activation can promote an interferon response, a phenomenon termed viral mimicry. Although ERV expression is associated with cancer, and provisionally with autoimmune and neurodegenerative diseases, ERV-mediated inflammation is being explored as a way to sensitize tumors to immunotherapy. Here we review ERV co-option in development and innate immunity, the aberrant contribution of ERVs to tumorigenesis, and the wider biomedical potential of therapies directed at ERVs.
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Affiliation(s)
- Natasha Jansz
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, QLD, 4102, Australia.
| | - Geoffrey J Faulkner
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, QLD, 4102, Australia. .,Queensland Brain Institute, University of Queensland, Brisbane, QLD, 4072, Australia.
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98
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Padmanabhan Nair V, Liu H, Ciceri G, Jungverdorben J, Frishman G, Tchieu J, Cederquist GY, Rothenaigner I, Schorpp K, Klepper L, Walsh RM, Kim TW, Cornacchia D, Ruepp A, Mayer J, Hadian K, Frishman D, Studer L, Vincendeau M. Activation of HERV-K(HML-2) disrupts cortical patterning and neuronal differentiation by increasing NTRK3. Cell Stem Cell 2021; 28:1566-1581.e8. [PMID: 33951478 DOI: 10.1016/j.stem.2021.04.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 03/05/2021] [Accepted: 04/12/2021] [Indexed: 12/20/2022]
Abstract
The biological function and disease association of human endogenous retroviruses (HERVs) are largely elusive. HERV-K(HML-2) has been associated with neurotoxicity, but there is no clear understanding of its role or mechanistic basis. We addressed the physiological functions of HERV-K(HML-2) in neuronal differentiation using CRISPR engineering to activate or repress its expression levels in a human-pluripotent-stem-cell-based system. We found that elevated HERV-K(HML-2) transcription is detrimental for the development and function of cortical neurons. These effects are cell-type-specific, as dopaminergic neurons are unaffected. Moreover, high HERV-K(HML-2) transcription alters cortical layer formation in forebrain organoids. HERV-K(HML-2) transcriptional activation leads to hyperactivation of NTRK3 expression and other neurodegeneration-related genes. Direct activation of NTRK3 phenotypically resembles HERV-K(HML-2) induction, and reducing NTRK3 levels in context of HERV-K(HML-2) induction restores cortical neuron differentiation. Hence, these findings unravel a cell-type-specific role for HERV-K(HML-2) in cortical neuron development.
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Affiliation(s)
| | - Hengyuan Liu
- Department of Genome-Oriented Bioinformatics, Technical University Munich, Munich, Germany
| | - Gabriele Ciceri
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Johannes Jungverdorben
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Goar Frishman
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jason Tchieu
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Gustav Y Cederquist
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ina Rothenaigner
- Assay Development and Screening Platform, Helmholtz Zentrum München, Neuherberg, Germany
| | - Kenji Schorpp
- Assay Development and Screening Platform, Helmholtz Zentrum München, Neuherberg, Germany
| | - Lena Klepper
- Institute of Virology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Ryan M Walsh
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Tae Wan Kim
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Daniela Cornacchia
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Andreas Ruepp
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jens Mayer
- Institute of Human Genetics, University of Saarland, Homburg, Germany
| | - Kamyar Hadian
- Assay Development and Screening Platform, Helmholtz Zentrum München, Neuherberg, Germany
| | - Dmitrij Frishman
- Department of Genome-Oriented Bioinformatics, Technical University Munich, Munich, Germany
| | - Lorenz Studer
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Michelle Vincendeau
- Institute of Virology, Helmholtz Zentrum München, Neuherberg, Germany; Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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Glinsky GV. Genomics-Guided Drawing of Molecular and Pathophysiological Components of Malignant Regulatory Signatures Reveals a Pivotal Role in Human Diseases of Stem Cell-Associated Retroviral Sequences and Functionally-Active hESC Enhancers. Front Oncol 2021; 11:638363. [PMID: 33869024 PMCID: PMC8044830 DOI: 10.3389/fonc.2021.638363] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 03/10/2021] [Indexed: 12/31/2022] Open
Abstract
Repetitive DNA sequences (repeats) colonized two-third of human genome and a majority of repeats comprised of transposable genetic elements (TE). Evolutionary distinct categories of TE represent nucleic acid sequences that are repeatedly copied from and pasted into chromosomes at multiple genomic locations and acquired a multitude of regulatory functions. Here, genomics-guided maps of stemness regulatory signatures were drawn to dissect the contribution of TE to clinical manifestations of malignant phenotypes of human cancers. From patients’ and physicians’ perspectives, the clinical definition of a tumor’s malignant phenotype could be restricted to the early diagnosis of sub-types of malignancies with the increased risk of existing therapy failure and high likelihood of death from cancer. It is the viewpoint from which the understanding of stemness and malignant regulatory signatures is considered in this contribution. Genomics-guided analyses of experimental and clinical observations revealed the pivotal role of human stem cell-associated retroviral sequences (SCARS) in the origin and pathophysiology of clinically-lethal malignancies. SCARS were defined as the evolutionary- and biologically-related family of genomic regulatory sequences, the principal physiological function of which is to create and maintain the stemness phenotype during human preimplantation embryogenesis. For cell differentiation to occur, SCARS expression must be silenced and SCARS activity remains repressed in most terminally-differentiated human cells which are destined to perform specialized functions in the human body. Epigenetic reprogramming, de-repression, and sustained activity of SCARS results in various differentiation-defective phenotypes. One of the most prominent tissue- and organ-specific clinical manifestations of sustained SCARS activities is diagnosed as a pathological condition defined by a consensus of morphological, molecular, and genetic examinations as the malignant growth. Here, contemporary evidence are acquired, analyzed, and reported defining both novel diagnostic tools and druggable molecular targets readily amenable for diagnosis and efficient therapeutic management of clinically-lethal malignancies. These diagnostic and therapeutic approaches are based on monitoring of high-fidelity molecular signals of continuing SCARS activities in conjunction with genomic regulatory networks of thousands’ functionally-active embryonic enhancers affecting down-stream phenotype-altering genetic loci. Collectively, reported herein observations support a model of SCARS-activation triggered singular source code facilitating the intracellular propagation and intercellular (systemic) dissemination of disease states in the human body.
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Affiliation(s)
- Gennadi V Glinsky
- Institute of Engineering in Medicine, University of California, San Diego, CA, United States.,Department of Functional & Translational Genomics, OncoSCAR, Inc., Portland, OR, United States
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Römer C. Viruses and Endogenous Retroviruses as Roots for Neuroinflammation and Neurodegenerative Diseases. Front Neurosci 2021; 15:648629. [PMID: 33776642 PMCID: PMC7994506 DOI: 10.3389/fnins.2021.648629] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 02/05/2021] [Indexed: 12/15/2022] Open
Abstract
Many neurodegenerative diseases are associated with chronic inflammation in the brain and periphery giving rise to a continuous imbalance of immune processes. Next to inflammation markers, activation of transposable elements, including long intrespersed nuclear elements (LINE) elements and endogenous retroviruses (ERVs), has been identified during neurodegenerative disease progression and even correlated with the clinical severity of the disease. ERVs are remnants of viral infections in the human genome acquired during evolution. Upon activation, they produce transcripts and the phylogenetically youngest ones are still able to produce viral-like particles. In addition, ERVs can bind transcription factors and modulate immune response. Being between own and foreign, ERVs are reviewed in the context of viral infections of the central nervous system, in aging and neurodegenerative diseases. Moreover, this review tests the hypothesis that viral infection may be a trigger at the onset of neuroinflammation and that ERVs sustain the inflammatory imbalance by summarizing existing data of neurodegenerative diseases associated with viruses and/or ERVs.
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Affiliation(s)
- Christine Römer
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, The Berlin Institute for Medical Systems Biology, Berlin, Germany
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