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Lin W, Wall JD, Li G, Newman D, Yang Y, Abney M, VandeBerg JL, Olivier M, Gilad Y, Cox LA. Genetic regulatory effects in response to a high-cholesterol, high-fat diet in baboons. Cell Genom 2024; 4:100509. [PMID: 38430910 PMCID: PMC10943580 DOI: 10.1016/j.xgen.2024.100509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/20/2023] [Accepted: 02/05/2024] [Indexed: 03/05/2024]
Abstract
Steady-state expression quantitative trait loci (eQTLs) explain only a fraction of disease-associated loci identified through genome-wide association studies (GWASs), while eQTLs involved in gene-by-environment (GxE) interactions have rarely been characterized in humans due to experimental challenges. Using a baboon model, we found hundreds of eQTLs that emerge in adipose, liver, and muscle after prolonged exposure to high dietary fat and cholesterol. Diet-responsive eQTLs exhibit genomic localization and genic features that are distinct from steady-state eQTLs. Furthermore, the human orthologs associated with diet-responsive eQTLs are enriched for GWAS genes associated with human metabolic traits, suggesting that context-responsive eQTLs with more complex regulatory effects are likely to explain GWAS hits that do not seem to overlap with standard eQTLs. Our results highlight the complexity of genetic regulatory effects and the potential of eQTLs with disease-relevant GxE interactions in enhancing the understanding of GWAS signals for human complex disease using non-human primate models.
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Affiliation(s)
- Wenhe Lin
- Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA.
| | - Jeffrey D Wall
- Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ge Li
- Center for Precision Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Deborah Newman
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78229, USA
| | - Yunqi Yang
- Committee on Genetics, Genomics and System Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Mark Abney
- Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA
| | - John L VandeBerg
- Department of Human Genetics, South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley, Brownsville, TX 78520, USA
| | - Michael Olivier
- Center for Precision Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Yoav Gilad
- Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA; Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL 60637, USA.
| | - Laura A Cox
- Center for Precision Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA; Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78229, USA.
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2
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McIntire E, Barr KA, Gonzales NM, Gilad Y. Guided Differentiation of Pluripotent Stem Cells for Cardiac Cell Diversity. bioRxiv 2024:2023.07.21.550072. [PMID: 37502898 PMCID: PMC10370173 DOI: 10.1101/2023.07.21.550072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
We have developed a guided differentiation protocol for induced pluripotent stem cells (iPSCs) that rapidly generates a temporally and functionally diverse set of cardiac-relevant cell types. By leveraging techniques used in embryoid body and cardiac organoid generation, we produce both progenitor and terminal cardiac cell types concomitantly in just 10 days. Our results show that guided differentiation generates functionally relevant cardiac cell types that closely align with the transcriptional profiles of cells from differentiation time-course collections, mature cardiac organoids, and in vivo heart tissue. Guided differentiation prioritizes simplicity by minimizing the number of reagents and steps required, thereby enabling rapid and cost-effective experimental throughput. We expect this approach will provide a scalable cardiac model for population-level studies of gene regulatory variation and gene-by-environment interactions.
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Affiliation(s)
- Erik McIntire
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Kenneth A Barr
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Natalia M Gonzales
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
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3
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Adegunsoye A, Gonzales NM, Gilad Y. Induced Pluripotent Stem Cells in Disease Biology and the Evidence for Their In Vitro Utility. Annu Rev Genet 2023; 57:341-360. [PMID: 37708421 DOI: 10.1146/annurev-genet-022123-090319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
Many human phenotypes are impossible to recapitulate in model organisms or immortalized human cell lines. Induced pluripotent stem cells (iPSCs) offer a way to study disease mechanisms in a variety of differentiated cell types while circumventing ethical and practical issues associated with finite tissue sources and postmortem states. Here, we discuss the broad utility of iPSCs in genetic medicine and describe how they are being used to study musculoskeletal, pulmonary, neurologic, and cardiac phenotypes. We summarize the particular challenges presented by each organ system and describe how iPSC models are being used to address them. Finally, we discuss emerging iPSC-derived organoid models and the potential value that they can bring to studies of human disease.
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Affiliation(s)
- Ayodeji Adegunsoye
- Genetics, Genomics, and Systems Biology, Section of Pulmonary and Critical Care, and the Department of Medicine, University of Chicago, Chicago, Illinois, USA;
| | - Natalia M Gonzales
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, Illinois, USA; ,
| | - Yoav Gilad
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, Illinois, USA; ,
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
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4
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Lin W, Wall JD, Li G, Newman D, Yang Y, Abney M, VandeBerg JL, Olivier M, Gilad Y, Cox LA. Genetic regulatory effects in response to a high cholesterol, high fat diet in baboons. bioRxiv 2023:2023.08.01.551489. [PMID: 37577666 PMCID: PMC10418186 DOI: 10.1101/2023.08.01.551489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Steady-state expression quantitative trait loci (eQTLs) explain only a fraction of disease-associated loci identified through genome-wide association studies (GWAS), while eQTLs involved in gene-by-environment (GxE) interactions have rarely been characterized in humans due to experimental challenges. Using a baboon model, we found hundreds of eQTLs that emerge in adipose, liver, and muscle after prolonged exposure to high dietary fat and cholesterol. Diet-responsive eQTLs exhibit genomic localization and genic features that are distinct from steady-state eQTLs. Furthermore, the human orthologs associated with diet-responsive eQTLs are enriched for GWAS genes associated with human metabolic traits, suggesting that context-responsive eQTLs with more complex regulatory effects are likely to explain GWAS hits that do not seem to overlap with standard eQTLs. Our results highlight the complexity of genetic regulatory effects and the potential of eQTLs with disease-relevant GxE interactions in enhancing the understanding of GWAS signals for human complex disease using nonhuman primate models.
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Affiliation(s)
- Wenhe Lin
- Department of Human Genetics, The University of Chicago, Chicago, USA
| | - Jeffrey D. Wall
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
- Present address: Galatea Bio, Hialeah, FL, USA
| | - Ge Li
- Center for Precision Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Deborah Newman
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Yunqi Yang
- Committee on Genetics, Genomics and System Biology, The University of Chicago, Chicago, USA
| | - Mark Abney
- Department of Human Genetics, The University of Chicago, Chicago, USA
| | - John L. VandeBerg
- Department of Human Genetics, South Texas Diabetes and Obesity Institute, University of Texas Rio Grand Valley, Brownsville, TX, USA
| | - Michael Olivier
- Center for Precision Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Yoav Gilad
- Department of Human Genetics, The University of Chicago, Chicago, USA
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, USA
- Lead contact
| | - Laura A. Cox
- Center for Precision Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
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5
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Barr KA, Rhodes KL, Gilad Y. The relationship between regulatory changes in cis and trans and the evolution of gene expression in humans and chimpanzees. Genome Biol 2023; 24:207. [PMID: 37697401 PMCID: PMC10496171 DOI: 10.1186/s13059-023-03019-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 07/21/2023] [Indexed: 09/13/2023] Open
Abstract
BACKGROUND Comparative gene expression studies in apes are fundamentally limited by the challenges associated with sampling across different tissues. Here, we used single-cell RNA sequencing of embryoid bodies to collect transcriptomic data from over 70 cell types in three humans and three chimpanzees. RESULTS We find hundreds of genes whose regulation is conserved across cell types, as well as genes whose regulation likely evolves under directional selection in one or a handful of cell types. Using embryoid bodies from a human-chimpanzee fused cell line, we also infer the proportion of inter-species regulatory differences due to changes in cis and trans elements between the species. Using the cis/trans inference and an analysis of transcription factor binding sites, we identify dozens of transcription factors whose inter-species differences in expression are affecting expression differences between humans and chimpanzees in hundreds of target genes. CONCLUSIONS Here, we present the most comprehensive dataset of comparative gene expression from humans and chimpanzees to date, including a catalog of regulatory mechanisms associated with inter-species differences.
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Affiliation(s)
- Kenneth A Barr
- Department of Medicine, University of Chicago, Chicago, IL, 60637, USA
| | | | - Yoav Gilad
- Department of Medicine, University of Chicago, Chicago, IL, 60637, USA.
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA.
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6
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Housman G, Briscoe E, Gilad Y. Evolutionary insights into primate skeletal gene regulation using a comparative cell culture model. PLoS Genet 2022; 18:e1010073. [PMID: 35263340 PMCID: PMC8936463 DOI: 10.1371/journal.pgen.1010073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 03/21/2022] [Accepted: 02/02/2022] [Indexed: 01/10/2023] Open
Abstract
The evolution of complex skeletal traits in primates was likely influenced by both genetic and environmental factors. Because skeletal tissues are notoriously challenging to study using functional genomic approaches, they remain poorly characterized even in humans, let alone across multiple species. The challenges involved in obtaining functional genomic data from the skeleton, combined with the difficulty of obtaining such tissues from nonhuman apes, motivated us to consider an alternative in vitro system with which to comparatively study gene regulation in skeletal cell types. Specifically, we differentiated six human (Homo sapiens) and six chimpanzee (Pan troglodytes) induced pluripotent stem cell lines (iPSCs) into mesenchymal stem cells (MSCs) and subsequently into osteogenic cells (bone cells). We validated differentiation using standard methods and collected single-cell RNA sequencing data from over 100,000 cells across multiple samples and replicates at each stage of differentiation. While most genes that we examined display conserved patterns of expression across species, hundreds of genes are differentially expressed (DE) between humans and chimpanzees within and across stages of osteogenic differentiation. Some of these interspecific DE genes show functional enrichments relevant in skeletal tissue trait development. Moreover, topic modeling indicates that interspecific gene programs become more pronounced as cells mature. Overall, we propose that this in vitro model can be used to identify interspecific regulatory differences that may have contributed to skeletal trait differences between species. Primates display a range of skeletal morphologies and susceptibilities to skeletal diseases, but the molecular basis of these phenotypic differences is unclear. Studies of gene expression variation in primate skeletal tissues are extremely restricted due to the ethical and practical challenges associated with collecting samples. Nevertheless, the ability to study gene regulation in primate skeletal tissues is crucial for understanding how the primate skeleton has evolved. We therefore developed a comparative primate skeletal cell culture model that allows us to access a spectrum of human and chimpanzee cell types as they differentiate from stem cells into bone cells. While most gene expression patterns are conserved across species, we also identified hundreds of differentially expressed genes between humans and chimpanzees within and across stages of differentiation. We also classified cells by osteogenic stage and identified additional interspecific differentially expressed genes which may contribute to skeletal trait differences. We anticipate that this model will be extremely useful for exploring questions related to gene regulation variation in primate bone biology and development.
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Affiliation(s)
- Genevieve Housman
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
| | - Emilie Briscoe
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Yoav Gilad
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
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7
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Rhodes K, Barr KA, Popp JM, Strober BJ, Battle A, Gilad Y. Human embryoid bodies as a novel system for genomic studies of functionally diverse cell types. eLife 2022; 11:71361. [PMID: 35142607 PMCID: PMC8830892 DOI: 10.7554/elife.71361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/18/2021] [Indexed: 12/23/2022] Open
Abstract
Practically all studies of gene expression in humans to date have been performed in a relatively small number of adult tissues. Gene regulation is highly dynamic and context-dependent. In order to better understand the connection between gene regulation and complex phenotypes, including disease, we need to be able to study gene expression in more cell types, tissues, and states that are relevant to human phenotypes. In particular, we need to characterize gene expression in early development cell types, as mutations that affect developmental processes may be of particular relevance to complex traits. To address this challenge, we propose to use embryoid bodies (EBs), which are organoids that contain a multitude of cell types in dynamic states. EBs provide a system in which one can study dynamic regulatory processes at an unprecedentedly high resolution. To explore the utility of EBs, we systematically explored cellular and gene expression heterogeneity in EBs from multiple individuals. We characterized the various cell types that arise from EBs, the extent to which they recapitulate gene expression in vivo, and the relative contribution of technical and biological factors to variability in gene expression, cell composition, and differentiation efficiency. Our results highlight the utility of EBs as a new model system for mapping dynamic inter-individual regulatory differences in a large variety of cell types. One major goal of human genetics is to understand how changes in the way genes are regulated affect human traits, including disease susceptibility. To date, most studies of gene regulation have been performed in adult tissues, such as liver or kidney tissue, that were collected at a single time point. Yet, gene regulation is highly dynamic and context-dependent, meaning that it is important to gather data from a greater variety of cell types at different stages of their development. Additionally, observing which genes switch on and off in response to external treatments can shed light on how genetic variation can drive errors in gene regulation and cause diseases. Stem cells can produce more cells like themselves or differentiate – acquire the characteristics – of many cell types. These cells have been used in the laboratory to research gene regulation. Unfortunately, these studies often fail to capture the complex spatial and temporal dynamics of stem cell differentiation; in particular, these studies are unable to observe gene regulation in the transient cell types that appear early in embryonic development. To overcome these limitations, scientists developed systems such as embryoid bodies: three-dimensional aggregates of stem cells that, when grown under certain conditions, spontaneously develop into a variety of cell types. Rhodes, Barr et al. wanted to assess the utility of embryoid bodies as a model to study how genes are dynamically regulated in different cell types, by different individuals who have distinct genetic makeups. To do this, they grew embryoid bodies made from human stem cells from different individuals to examine which genes switched on and off as the stem cells that formed the embryoid bodies differentiated into different types of cells. The results showed that it was possible to grow embryoid bodies derived from genetically distinct individuals that consistently produce diverse cell types, similar to those found during human fetal development. Rhodes, Barr et al.’s findings suggest that embryoid bodies are a useful model to study gene regulation across individuals with different genetic backgrounds. This could accelerate research into how genetics are associated with disease by capturing gene regulatory dynamics at an unprecedentedly high spatial and temporal resolution. Additionally, embryoid bodies could be used to explore how exposure to different environmental factors during early development affect disease-related outcomes in adulthood in different individuals.
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Affiliation(s)
- Katherine Rhodes
- Department of Medicine, University of Chicago, Chicago, United States
| | - Kenneth A Barr
- Department of Medicine, University of Chicago, Chicago, United States
| | - Joshua M Popp
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States
| | - Benjamin J Strober
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States
| | - Alexis Battle
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States.,Department of Computer Science, Johns Hopkins University, Baltimore, United States.,Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, United States
| | - Yoav Gilad
- Department of Medicine, University of Chicago, Chicago, United States
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8
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Elorbany R, Popp JM, Rhodes K, Strober BJ, Barr K, Qi G, Gilad Y, Battle A. Single-cell sequencing reveals lineage-specific dynamic genetic regulation of gene expression during human cardiomyocyte differentiation. PLoS Genet 2022; 18:e1009666. [PMID: 35061661 PMCID: PMC8809621 DOI: 10.1371/journal.pgen.1009666] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 02/02/2022] [Accepted: 12/21/2021] [Indexed: 12/13/2022] Open
Abstract
Dynamic and temporally specific gene regulatory changes may underlie unexplained genetic associations with complex disease. During a dynamic process such as cellular differentiation, the overall cell type composition of a tissue (or an in vitro culture) and the gene regulatory profile of each cell can both experience significant changes over time. To identify these dynamic effects in high resolution, we collected single-cell RNA-sequencing data over a differentiation time course from induced pluripotent stem cells to cardiomyocytes, sampled at 7 unique time points in 19 human cell lines. We employed a flexible approach to map dynamic eQTLs whose effects vary significantly over the course of bifurcating differentiation trajectories, including many whose effects are specific to one of these two lineages. Our study design allowed us to distinguish true dynamic eQTLs affecting a specific cell lineage from expression changes driven by potentially non-genetic differences between cell lines such as cell composition. Additionally, we used the cell type profiles learned from single-cell data to deconvolve and re-analyze data from matched bulk RNA-seq samples. Using this approach, we were able to identify a large number of novel dynamic eQTLs in single cell data while also attributing dynamic effects in bulk to a particular lineage. Overall, we found that using single cell data to uncover dynamic eQTLs can provide new insight into the gene regulatory changes that occur among heterogeneous cell types during cardiomyocyte differentiation.
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Affiliation(s)
- Reem Elorbany
- Interdisciplinary Scientist Training Program, University of Chicago, Chicago, Illinois, United States of America
| | - Joshua M. Popp
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Katherine Rhodes
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Benjamin J. Strober
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Kenneth Barr
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Guanghao Qi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Alexis Battle
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Computer Science, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
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9
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Shah A, Mittleman BE, Gilad Y, Li YI. Benchmarking sequencing methods and tools that facilitate the study of alternative polyadenylation. Genome Biol 2021; 22:291. [PMID: 34649612 PMCID: PMC8518154 DOI: 10.1186/s13059-021-02502-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 09/16/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Alternative cleavage and polyadenylation (APA), an RNA processing event, occurs in over 70% of human protein-coding genes. APA results in mRNA transcripts with distinct 3' ends. Most APA occurs within 3' UTRs, which harbor regulatory elements that can impact mRNA stability, translation, and localization. RESULTS APA can be profiled using a number of established computational tools that infer polyadenylation sites from standard, short-read RNA-seq datasets. Here, we benchmarked a number of such tools-TAPAS, QAPA, DaPars2, GETUTR, and APATrap- against 3'-Seq, a specialized RNA-seq protocol that enriches for reads at the 3' ends of genes, and Iso-Seq, a Pacific Biosciences (PacBio) single-molecule full-length RNA-seq method in their ability to identify polyadenylation sites and quantify polyadenylation site usage. We demonstrate that 3'-Seq and Iso-Seq are able to identify and quantify the usage of polyadenylation sites more reliably than computational tools that take short-read RNA-seq as input. However, we find that running one such tool, QAPA, with a set of polyadenylation site annotations derived from small quantities of 3'-Seq or Iso-Seq can reliably quantify variation in APA across conditions, such asacross genotypes, as demonstrated by the successful mapping of alternative polyadenylation quantitative trait loci (apaQTL). CONCLUSIONS We envisage that our analyses will shed light on the advantages of studying APA with more specialized sequencing protocols, such as 3'-Seq or Iso-Seq, and the limitations of studying APA with short-read RNA-seq. We provide a computational pipeline to aid in the identification of polyadenylation sites and quantification of polyadenylation site usages using Iso-Seq data as input.
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Affiliation(s)
- Ankeeta Shah
- Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
| | - Briana E Mittleman
- Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
| | - Yoav Gilad
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Yang I Li
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA.
- Department of Human Genetics, University of Chicago, Chicago, IL, USA.
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10
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Findley AS, Monziani A, Richards AL, Rhodes K, Ward MC, Kalita CA, Alazizi A, Pazokitoroudi A, Sankararaman S, Wen X, Lanfear DE, Pique-Regi R, Gilad Y, Luca F. Functional dynamic genetic effects on gene regulation are specific to particular cell types and environmental conditions. eLife 2021; 10:e67077. [PMID: 33988505 PMCID: PMC8248987 DOI: 10.7554/elife.67077] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/13/2021] [Indexed: 12/14/2022] Open
Abstract
Genetic effects on gene expression and splicing can be modulated by cellular and environmental factors; yet interactions between genotypes, cell type, and treatment have not been comprehensively studied together. We used an induced pluripotent stem cell system to study multiple cell types derived from the same individuals and exposed them to a large panel of treatments. Cellular responses involved different genes and pathways for gene expression and splicing and were highly variable across contexts. For thousands of genes, we identified variable allelic expression across contexts and characterized different types of gene-environment interactions, many of which are associated with complex traits. Promoter functional and evolutionary features distinguished genes with elevated allelic imbalance mean and variance. On average, half of the genes with dynamic regulatory interactions were missed by large eQTL mapping studies, indicating the importance of exploring multiple treatments to reveal previously unrecognized regulatory loci that may be important for disease.
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Affiliation(s)
- Anthony S Findley
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
| | - Alan Monziani
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
| | - Allison L Richards
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
| | - Katherine Rhodes
- Department of Human Genetics, University of ChicagoChicagoUnited States
| | - Michelle C Ward
- Department of Medicine, University of ChicagoChicagoUnited States
| | - Cynthia A Kalita
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
| | - Adnan Alazizi
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
| | | | - Sriram Sankararaman
- Department of Computer Science, UCLALos AngelesUnited States
- Department of Human Genetics, UCLALos AngelesUnited States
- Department of Computational Medicine, UCLALos AngelesUnited States
| | - Xiaoquan Wen
- Department of Biostatistics, University of MichiganAnn ArborUnited States
| | - David E Lanfear
- Center for Individualized and Genomic Medicine Research, Henry Ford HospitalDetroitUnited States
| | - Roger Pique-Regi
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
- Department of Obstetrics and Gynecology, Wayne State UniversityDetroitUnited States
| | - Yoav Gilad
- Department of Human Genetics, University of ChicagoChicagoUnited States
- Department of Medicine, University of ChicagoChicagoUnited States
| | - Francesca Luca
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
- Department of Obstetrics and Gynecology, Wayne State UniversityDetroitUnited States
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11
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Mittleman BE, Pott S, Warland S, Barr K, Cuevas C, Gilad Y. Divergence in alternative polyadenylation contributes to gene regulatory differences between humans and chimpanzees. eLife 2021; 10:e62548. [PMID: 33595436 PMCID: PMC7954529 DOI: 10.7554/elife.62548] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 02/12/2021] [Indexed: 12/12/2022] Open
Abstract
While comparative functional genomic studies have shown that inter-species differences in gene expression can be explained by corresponding inter-species differences in genetic and epigenetic regulatory mechanisms, co-transcriptional mechanisms, such as alternative polyadenylation (APA), have received little attention. We characterized APA in lymphoblastoid cell lines from six humans and six chimpanzees by identifying and estimating the usage for 44,432 polyadenylation sites (PAS) in 9518 genes. Although APA is largely conserved, 1705 genes showed significantly different PAS usage (FDR 0.05) between species. Genes with divergent APA also tend to be differentially expressed, are enriched among genes showing differences in protein translation, and can explain a subset of observed inter-species protein expression differences that do not differ at the transcript level. Finally, we found that genes with a dominant PAS, which is used more often than other PAS, are particularly enriched for differentially expressed genes.
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Affiliation(s)
- Briana E Mittleman
- Genetics, Genomics and Systems Biology, University of ChicagoChicagoUnited States
| | - Sebastian Pott
- Department of Human Genetics, University of ChicagoChicagoUnited States
| | - Shane Warland
- Section of Genetic Medicine, Department of Medicine, University of ChicagoChicagoUnited States
| | - Kenneth Barr
- Section of Genetic Medicine, Department of Medicine, University of ChicagoChicagoUnited States
| | - Claudia Cuevas
- Section of Genetic Medicine, Department of Medicine, University of ChicagoChicagoUnited States
| | - Yoav Gilad
- Department of Human Genetics, University of ChicagoChicagoUnited States
- Section of Genetic Medicine, Department of Medicine, University of ChicagoChicagoUnited States
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12
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Ward MC, Banovich NE, Sarkar A, Stephens M, Gilad Y. Dynamic effects of genetic variation on gene expression revealed following hypoxic stress in cardiomyocytes. eLife 2021; 10:57345. [PMID: 33554857 PMCID: PMC7906610 DOI: 10.7554/elife.57345] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 02/06/2021] [Indexed: 12/13/2022] Open
Abstract
One life-threatening outcome of cardiovascular disease is myocardial infarction, where cardiomyocytes are deprived of oxygen. To study inter-individual differences in response to hypoxia, we established an in vitro model of induced pluripotent stem cell-derived cardiomyocytes from 15 individuals. We measured gene expression levels, chromatin accessibility, and methylation levels in four culturing conditions that correspond to normoxia, hypoxia, and short- or long-term re-oxygenation. We characterized thousands of gene regulatory changes as the cells transition between conditions. Using available genotypes, we identified 1,573 genes with a cis expression quantitative locus (eQTL) in at least one condition, as well as 367 dynamic eQTLs, which are classified as eQTLs in at least one, but not in all conditions. A subset of genes with dynamic eQTLs is associated with complex traits and disease. Our data demonstrate how dynamic genetic effects on gene expression, which are likely relevant for disease, can be uncovered under stress.
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Affiliation(s)
- Michelle C Ward
- Department of Medicine, University of Chicago, Chicago, United States.,Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, United States
| | - Nicholas E Banovich
- Department of Human Genetics, University of Chicago, Chicago, United States.,Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, United States
| | - Abhishek Sarkar
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Matthew Stephens
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Statistics, University of Chicago, Chicago, United States
| | - Yoav Gilad
- Department of Medicine, University of Chicago, Chicago, United States.,Department of Human Genetics, University of Chicago, Chicago, United States
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13
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Abstract
Most disease-associated variants, although located in putatively regulatory regions, do not have detectable effects on gene expression. One explanation could be that we have not examined gene expression in the cell types or conditions that are most relevant for disease. Even large-scale efforts to study gene expression across tissues are limited to human samples obtained opportunistically or postmortem, mostly from adults. In this review we evaluate recent findings and suggest an alternative strategy, drawing on the dynamic and highly context-specific nature of gene regulation. We discuss new technologies that can extend the standard regulatory mapping framework to more diverse, disease-relevant cell types and states.
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Affiliation(s)
- Benjamin D Umans
- Department of Medicine, University of Chicago, Chicago, IL, USA.
| | - Alexis Battle
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA.
| | - Yoav Gilad
- Department of Medicine, University of Chicago, Chicago, IL, USA; Department of Human Genetics, University of Chicago, Chicago, IL, USA.
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14
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Abstract
The notion that topologically associating domains (TADs) are highly conserved across species is prevalent in the field of 3D genomics. However, what exactly is meant by 'highly conserved' and what are the actual comparative data that support this notion? To address these questions, we performed a historical review of the relevant literature and retraced numerous citation chains to reveal the primary data that were used as the basis for the widely accepted conclusion that TADs are highly conserved across evolution. A thorough review of the available evidence suggests the answer may be more complex than what is commonly presented.
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Affiliation(s)
- Ittai E Eres
- Department of Human Genetics, University of Chicago, Cummings Life Science Center, 928 E. 58th St., Chicago, IL 60637, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Cummings Life Science Center, 928 E. 58th St., Chicago, IL 60637, USA; Section of Genetic Medicine, Department of Medicine, University of Chicago, 5841 S. Maryland Ave., N417, MC6091, Chicago, IL 60637, USA.
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15
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Fair BJ, Blake LE, Sarkar A, Pavlovic BJ, Cuevas C, Gilad Y. Gene expression variability in human and chimpanzee populations share common determinants. eLife 2020; 9:59929. [PMID: 33084571 PMCID: PMC7644215 DOI: 10.7554/elife.59929] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/20/2020] [Indexed: 12/20/2022] Open
Abstract
Inter-individual variation in gene expression has been shown to be heritable and is often associated with differences in disease susceptibility between individuals. Many studies focused on mapping associations between genetic and gene regulatory variation, yet much less attention has been paid to the evolutionary processes that shape the observed differences in gene regulation between individuals in humans or any other primate. To begin addressing this gap, we performed a comparative analysis of gene expression variability and expression quantitative trait loci (eQTLs) in humans and chimpanzees, using gene expression data from primary heart samples. We found that expression variability in both species is often determined by non-genetic sources, such as cell-type heterogeneity. However, we also provide evidence that inter-individual variation in gene regulation can be genetically controlled, and that the degree of such variability is generally conserved in humans and chimpanzees. In particular, we found a significant overlap of orthologous genes associated with eQTLs in both species. We conclude that gene expression variability in humans and chimpanzees often evolves under similar evolutionary pressures.
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Affiliation(s)
| | - Lauren E Blake
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Abhishek Sarkar
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Bryan J Pavlovic
- Department of Neurology, University of California, San Francisco (UCSF), San Francisco, United States
| | - Claudia Cuevas
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Yoav Gilad
- Department of Medicine, University of Chicago, Chicago, United States.,Department of Human Genetics, University of Chicago, Chicago, United States
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16
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Mittleman BE, Pott S, Warland S, Zeng T, Mu Z, Kaur M, Gilad Y, Li Y. Alternative polyadenylation mediates genetic regulation of gene expression. eLife 2020; 9:57492. [PMID: 32584258 PMCID: PMC7338057 DOI: 10.7554/elife.57492] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/17/2020] [Indexed: 12/22/2022] Open
Abstract
Little is known about co-transcriptional or post-transcriptional regulatory mechanisms linking noncoding variation to variation in organismal traits. To begin addressing this gap, we used 3’ Seq to study the impact of genetic variation on alternative polyadenylation (APA) in the nuclear and total mRNA fractions of 52 HapMap Yoruba human lymphoblastoid cell lines. We mapped 602 APA quantitative trait loci (apaQTLs) at 10% FDR, of which 152 were nuclear specific. Effect sizes at intronic apaQTLs are negatively correlated with eQTL effect sizes. These observations suggest genetic variants can decrease mRNA expression levels by increasing usage of intronic PAS. We also identified 24 apaQTLs associated with protein levels, but not mRNA expression. Finally, we found that 19% of apaQTLs can be associated with disease. Thus, our work demonstrates that APA links genetic variation to variation in gene expression, protein expression, and disease risk, and reveals uncharted modes of genetic regulation.
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Affiliation(s)
- Briana E Mittleman
- Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, United States
| | - Sebastian Pott
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Shane Warland
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, United States
| | - Tony Zeng
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, United States
| | - Zepeng Mu
- Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, United States
| | - Mayher Kaur
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, United States
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, United States.,Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, United States
| | - Yang Li
- Department of Human Genetics, University of Chicago, Chicago, United States.,Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, United States
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17
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Abstract
Functional genomics research is continually improving our understanding of genotype-phenotype relationships in humans, and comparative genomics perspectives can provide additional insight into the evolutionary histories of such relationships. To specifically identify conservation or species-specific divergence in humans, we must look to our closest extant evolutionary relatives. Primate functional genomics research has been steadily advancing and expanding, in spite of several limitations and challenges that this field faces. New technologies and cheaper sequencing provide a unique opportunity to enhance and expand primate comparative studies, and we outline possible paths going forward. The potential human-specific insights that can be gained from primate functional genomics research are substantial, and we propose that now is a prime time to expand such endeavors.
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Affiliation(s)
- Genevieve Housman
- Section of Genetic Medicine, Department of Medicine, University of Chicago, 5841 S. Maryland Ave., N417, MC6091, Chicago, IL 60637 USA.
| | - Yoav Gilad
- Section of Genetic Medicine, Department of Medicine, University of Chicago, 5841 S. Maryland Ave., N417, MC6091, Chicago, IL 60637 USA; Department of Human Genetics, University of Chicago, Cummings Life Science Center, 928 E. 58th St., Chicago, IL 60637 USA
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18
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Selewa A, Dohn R, Eckart H, Lozano S, Xie B, Gauchat E, Elorbany R, Rhodes K, Burnett J, Gilad Y, Pott S, Basu A. Systematic Comparison of High-throughput Single-Cell and Single-Nucleus Transcriptomes during Cardiomyocyte Differentiation. Sci Rep 2020; 10:1535. [PMID: 32001747 PMCID: PMC6992778 DOI: 10.1038/s41598-020-58327-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 01/14/2020] [Indexed: 11/21/2022] Open
Abstract
A comprehensive reference map of all cell types in the human body is necessary for improving our understanding of fundamental biological processes and in diagnosing and treating disease. High-throughput single-cell RNA sequencing techniques have emerged as powerful tools to identify and characterize cell types in complex and heterogeneous tissues. However, extracting intact cells from tissues and organs is often technically challenging or impossible, for example in heart or brain tissue. Single-nucleus RNA sequencing provides an alternative way to obtain transcriptome profiles of such tissues. To systematically assess the differences between high-throughput single-cell and single-nuclei RNA-seq approaches, we compared Drop-seq and DroNc-seq, two microfluidic-based 3' RNA capture technologies that profile total cellular and nuclear RNA, respectively, during a time course experiment of human induced pluripotent stem cells (iPSCs) differentiating into cardiomyocytes. Clustering of time-series transcriptomes from Drop-seq and DroNc-seq revealed six distinct cell types, five of which were found in both techniques. Furthermore, single-cell trajectories reconstructed from both techniques reproduced expected differentiation dynamics. We then applied DroNc-seq to postmortem heart tissue to test its performance on heterogeneous human tissue samples. Our data confirm that DroNc-seq yields similar results to Drop-seq on matched samples and can be successfully used to generate reference maps for the human cell atlas.
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Affiliation(s)
- Alan Selewa
- Department of Medicine, University of Chicago, Chicago, USA
- Biophysical Sciences Graduate Program, University of Chicago, Chicago, USA
| | - Ryan Dohn
- Department of Medicine, University of Chicago, Chicago, USA
| | - Heather Eckart
- Department of Medicine, University of Chicago, Chicago, USA
| | | | - Bingqing Xie
- Department of Medicine, University of Chicago, Chicago, USA
| | - Eric Gauchat
- Department of Medicine, University of Chicago, Chicago, USA
- Biophysical Sciences Graduate Program, University of Chicago, Chicago, USA
| | - Reem Elorbany
- Department of Human Genetics, University of Chicago, Chicago, USA
| | - Katherine Rhodes
- Department of Human Genetics, University of Chicago, Chicago, USA
| | - Jonathan Burnett
- Department of Human Genetics, University of Chicago, Chicago, USA
| | - Yoav Gilad
- Department of Medicine, University of Chicago, Chicago, USA
- Department of Human Genetics, University of Chicago, Chicago, USA
| | - Sebastian Pott
- Department of Human Genetics, University of Chicago, Chicago, USA.
| | - Anindita Basu
- Department of Medicine, University of Chicago, Chicago, USA.
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, USA.
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19
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Blake LE, Roux J, Hernando-Herraez I, Banovich NE, Perez RG, Hsiao CJ, Eres I, Cuevas C, Marques-Bonet T, Gilad Y. A comparison of gene expression and DNA methylation patterns across tissues and species. Genome Res 2020; 30:250-262. [PMID: 31953346 PMCID: PMC7050529 DOI: 10.1101/gr.254904.119] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 01/02/2020] [Indexed: 01/02/2023]
Abstract
Previously published comparative functional genomic data sets from primates using frozen tissue samples, including many data sets from our own group, were often collected and analyzed using nonoptimal study designs and analysis approaches. In addition, when samples from multiple tissues were studied in a comparative framework, individuals and tissues were confounded. We designed a multitissue comparative study of gene expression and DNA methylation in primates that minimizes confounding effects by using a balanced design with respect to species, tissues, and individuals. We also developed a comparative analysis pipeline that minimizes biases attributable to sequence divergence. Thus, we present the most comprehensive catalog of similarities and differences in gene expression and DNA methylation levels between livers, kidneys, hearts, and lungs, in humans, chimpanzees, and rhesus macaques. We estimate that overall, interspecies and inter-tissue differences in gene expression levels can only modestly be accounted for by corresponding differences in promoter DNA methylation. However, the expression pattern of genes with conserved inter-tissue expression differences can be explained by corresponding interspecies methylation changes more often. Finally, we show that genes whose tissue-specific regulatory patterns are consistent with the action of natural selection are highly connected in both gene regulatory and protein–protein interaction networks.
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Affiliation(s)
- Lauren E Blake
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Julien Roux
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA.,Department of Biomedicine, University of Basel, 4031 Basel, Switzerland.,Swiss Institute of Bioinformatics, 4031 Basel, Switzerland
| | | | - Nicholas E Banovich
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Raquel Garcia Perez
- Universitat Pompeu Fabra, Institute of Evolutionary Biology, 88 08003 Barcelona, Spain
| | - Chiaowen Joyce Hsiao
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Ittai Eres
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Claudia Cuevas
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Tomas Marques-Bonet
- Universitat Pompeu Fabra, Institute of Evolutionary Biology, 88 08003 Barcelona, Spain.,Passeig de Lluís Companys, Catalan Institution of Research and Advanced Studies, 23 08010 Barcelona, Spain.,Barcelona Institute of Science and Technology, Centre for Genomic Regulation, 88 08003 Barcelona, Spain.,Universitat Autònoma de Barcelona, Institut Català de Paleontologia Miquel Crusafont, 08193 Barcelona, Spain
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA.,Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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20
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Eres IE, Luo K, Hsiao CJ, Blake LE, Gilad Y. Reorganization of 3D genome structure may contribute to gene regulatory evolution in primates. PLoS Genet 2019; 15:e1008278. [PMID: 31323043 PMCID: PMC6668850 DOI: 10.1371/journal.pgen.1008278] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 07/31/2019] [Accepted: 06/28/2019] [Indexed: 12/22/2022] Open
Abstract
A growing body of evidence supports the notion that variation in gene regulation plays a crucial role in both speciation and adaptation. However, a comprehensive functional understanding of the mechanisms underlying regulatory evolution remains elusive. In primates, one of the crucial missing pieces of information towards a better understanding of regulatory evolution is a comparative annotation of interactions between distal regulatory elements and promoters. Chromatin conformation capture technologies have enabled genome-wide quantifications of such distal 3D interactions. However, relatively little comparative research in primates has been done using such technologies. To address this gap, we used Hi-C to characterize 3D chromatin interactions in induced pluripotent stem cells (iPSCs) from humans and chimpanzees. We also used RNA-seq to collect gene expression data from the same lines. We generally observed that lower-order, pairwise 3D genomic interactions are conserved in humans and chimpanzees, but higher order genomic structures, such as topologically associating domains (TADs), are not as conserved. Inter-species differences in 3D genomic interactions are often associated with gene expression differences between the species. To provide additional functional context to our observations, we considered previously published chromatin data from human stem cells. We found that inter-species differences in 3D genomic interactions, which are also associated with gene expression differences between the species, are enriched for both active and repressive marks. Overall, our data demonstrate that, as expected, an understanding of 3D genome reorganization is key to explaining regulatory evolution. The way in which a genome folds affects the regulation of gene expression. This is often due to loops in the three-dimensional structure that bring linearly distant genes and regulatory elements into close proximity. Most studies examining three-dimensional structure genome-wide are limited to a single species. In this study, we compared three-dimensional structure in the genomes of induced pluripotent stem cells from humans and chimpanzees. We collected gene expression data from the same samples, which allowed us to assess the contribution of three-dimensional chromatin conformation to gene regulatory evolution in primates. Our results demonstrate that gene expression differences between the species may often be mediated by differences in three-dimensional genomic interactions. Our data also suggest that large-scale chromatin structures (i.e. topologically associating domains, TADs) are not well conserved in their placement across species. We hope the analytical paradigms we present here could serve as a basis for future comparative studies of three-dimensional genome organization, elucidating the putative functional regulatory loci driving speciation.
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Affiliation(s)
- Ittai E. Eres
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Kaixuan Luo
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Chiaowen Joyce Hsiao
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Lauren E. Blake
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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21
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Strober BJ, Elorbany R, Rhodes K, Krishnan N, Tayeb K, Battle A, Gilad Y. Dynamic genetic regulation of gene expression during cellular differentiation. Science 2019; 364:1287-1290. [PMID: 31249060 PMCID: PMC6623972 DOI: 10.1126/science.aaw0040] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 06/04/2019] [Indexed: 12/12/2022]
Abstract
Genetic regulation of gene expression is dynamic, as transcription can change during cell differentiation and across cell types. We mapped expression quantitative trait loci (eQTLs) throughout differentiation to elucidate the dynamics of genetic effects on cell type-specific gene expression. We generated time-series RNA sequencing data, capturing 16 time points during the differentiation of induced pluripotent stem cells to cardiomyocytes, in 19 human cell lines. We identified hundreds of dynamic eQTLs that change over time, with enrichment in enhancers of relevant cell types. We also found nonlinear dynamic eQTLs, which affect only intermediate stages of differentiation and cannot be found by using data from mature tissues. These fleeting genetic associations with gene regulation may explain some of the components of complex traits and disease. We highlight one example of a nonlinear eQTL that is associated with body mass index.
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Affiliation(s)
- B J Strober
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - R Elorbany
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL 60637, USA
- Interdisciplinary Scientist Training Program, University of Chicago, Chicago, IL 60637, USA
| | - K Rhodes
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - N Krishnan
- Department of Computer Science, Johns Hopkins University, Baltimore, MD 21218, USA
| | - K Tayeb
- Department of Applied Mathematics and Statistics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - A Battle
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
- Department of Computer Science, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Y Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA.
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
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22
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Ward MC, Gilad Y. A generally conserved response to hypoxia in iPSC-derived cardiomyocytes from humans and chimpanzees. eLife 2019; 8:42374. [PMID: 30958265 PMCID: PMC6538380 DOI: 10.7554/elife.42374] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 04/07/2019] [Indexed: 12/23/2022] Open
Abstract
Despite anatomical similarities, there are differences in susceptibility to cardiovascular disease (CVD) between primates; humans are prone to myocardial ischemia, while chimpanzees are prone to myocardial fibrosis. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) allow for direct inter-species comparisons of the gene regulatory response to CVD-relevant perturbations such as oxygen deprivation, a consequence of ischemia. To gain insight into the evolution of disease susceptibility, we characterized gene expression levels in iPSC-CMs in humans and chimpanzees, before and after hypoxia and re-oxygenation. The transcriptional response to hypoxia is generally conserved across species, yet we were able to identify hundreds of species-specific regulatory responses including in genes previously associated with CVD. The 1,920 genes that respond to hypoxia in both species are enriched for loss-of-function intolerant genes; but are depleted for expression quantitative trait loci and cardiovascular-related genes. Our results indicate that response to hypoxic stress is highly conserved in humans and chimpanzees.
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Affiliation(s)
- Michelle C Ward
- Department of Medicine, University of Chicago, Chicago, United States
| | - Yoav Gilad
- Department of Medicine, University of Chicago, Chicago, United States.,Department of Human Genetics, University of Chicago, Chicago, United States
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23
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Pavlovic BJ, Blake LE, Roux J, Chavarria C, Gilad Y. A Comparative Assessment of Human and Chimpanzee iPSC-derived Cardiomyocytes with Primary Heart Tissues. Sci Rep 2018; 8:15312. [PMID: 30333510 PMCID: PMC6193013 DOI: 10.1038/s41598-018-33478-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 09/28/2018] [Indexed: 01/27/2023] Open
Abstract
Comparative genomic studies in primates have the potential to reveal the genetic and mechanistic basis for human specific traits. These studies may also help us better understand inter-species phenotypic differences that are clinically relevant. Unfortunately, the obvious limitation on sample collection and experimentation in humans and non-human apes severely restrict our ability to perform dynamic comparative studies in primates. Induced pluripotent stem cells (iPSCs), and their corresponding differentiated cells, may provide a suitable alternative system for dynamic comparative studies. Yet, to effectively use iPSCs and differentiated cells for comparative studies, one must characterize the extent to which these systems faithfully represent biological processes in primary tissues. To do so, we compared gene expression data from primary adult heart tissue and iPSC-derived cardiomyocytes from multiple human and chimpanzee individuals. We determined that gene expression in cultured cardiomyocytes from both human and chimpanzee is most similar to that of adult hearts compared to other adult tissues. Using a comparative framework, we found that 50% of gene regulatory differences between human and chimpanzee hearts are also observed between species in cultured cardiomyocytes; conversely, inter-species regulatory differences seen in cardiomyocytes are found significantly more often in hearts than in other primary tissues. Our work provides a detailed description of the utility and limitation of differentiated cardiomyocytes as a system for comparative functional genomic studies in primates.
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Affiliation(s)
- Bryan J Pavlovic
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA.
| | - Lauren E Blake
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Julien Roux
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
| | - Claudia Chavarria
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA.
- Department of Medicine, University of Chicago, Chicago, Illinois, USA.
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24
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Blake LE, Thomas SM, Blischak JD, Hsiao CJ, Chavarria C, Myrthil M, Gilad Y, Pavlovic BJ. A comparative study of endoderm differentiation in humans and chimpanzees. Genome Biol 2018; 19:162. [PMID: 30322406 PMCID: PMC6191992 DOI: 10.1186/s13059-018-1490-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 07/20/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND There is substantial interest in the evolutionary forces that shaped the regulatory framework in early human development. Progress in this area has been slow because it is difficult to obtain relevant biological samples. Induced pluripotent stem cells (iPSCs) may provide the ability to establish in vitro models of early human and non-human primate developmental stages. RESULTS Using matched iPSC panels from humans and chimpanzees, we comparatively characterize gene regulatory changes through a four-day time course differentiation of iPSCs into primary streak, endoderm progenitors, and definitive endoderm. As might be expected, we find that differentiation stage is the major driver of variation in gene expression levels, followed by species. We identify thousands of differentially expressed genes between humans and chimpanzees in each differentiation stage. Yet, when we consider gene-specific dynamic regulatory trajectories throughout the time course, we find that at least 75% of genes, including nearly all known endoderm developmental markers, have similar trajectories in the two species. Interestingly, we observe a marked reduction of both intra- and inter-species variation in gene expression levels in primitive streak samples compared to the iPSCs, with a recovery of regulatory variation in endoderm progenitors. CONCLUSIONS The reduction of variation in gene expression levels at a specific developmental stage, paired with overall high degree of conservation of temporal gene regulation, is consistent with the dynamics of a conserved developmental process.
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Affiliation(s)
- Lauren E. Blake
- Department of Human Genetics, University of Chicago, Chicago, IL USA
| | | | - John D. Blischak
- Department of Human Genetics, University of Chicago, Chicago, IL USA
| | | | - Claudia Chavarria
- Department of Human Genetics, University of Chicago, Chicago, IL USA
| | - Marsha Myrthil
- Department of Human Genetics, University of Chicago, Chicago, IL USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL USA
- Department of Medicine, University of Chicago, Chicago, IL USA
- Cummings Life Sciences Center, 920 E. 58th Street, CLSC 317, Chicago, IL 60637 USA
| | - Bryan J. Pavlovic
- Department of Human Genetics, University of Chicago, Chicago, IL USA
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25
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Engelmann BW, Hsiao CJ, Blischak JD, Fourne Y, Khan Z, Ford M, Gilad Y. A Methodological Assessment and Characterization of Genetically-Driven Variation in Three Human Phosphoproteomes. Sci Rep 2018; 8:12106. [PMID: 30108239 PMCID: PMC6092387 DOI: 10.1038/s41598-018-30587-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/17/2018] [Indexed: 11/12/2022] Open
Abstract
Phosphorylation of proteins on serine, threonine, and tyrosine residues is a ubiquitous post-translational modification that plays a key part of essentially every cell signaling process. It is reasonable to assume that inter-individual variation in protein phosphorylation may underlie phenotypic differences, as has been observed for practically any other molecular regulatory phenotype. However, we do not know much about the extent of inter-individual variation in phosphorylation because it is quite challenging to perform a quantitative high throughput study to assess inter-individual variation in any post-translational modification. To test our ability to address this challenge with SILAC-based mass spectrometry, we quantified phosphorylation levels for three genotyped human cell lines within a nested experimental framework, and found that genetic background is the primary determinant of phosphoproteome variation. We uncovered multiple functional, biophysical, and genetic associations with germline driven phosphopeptide variation. Variants affecting protein levels or structure were among these associations, with the latter presenting, on average, a stronger effect. Interestingly, we found evidence that is consistent with a phosphopeptide variability buffering effect endowed from properties enriched within longer proteins. Because the small sample size in this 'pilot' study may limit the applicability of our genetic observations, we also undertook a thorough technical assessment of our experimental workflow to aid further efforts. Taken together, these results provide the foundation for future work to characterize inter-individual variation in post-translational modification levels and reveal novel insights into the nature of inter-individual variation in phosphorylation.
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Affiliation(s)
- Brett W Engelmann
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA.
- AbbVie, North Chicago, Illinois, USA.
| | | | - John D Blischak
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Yannick Fourne
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Zia Khan
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
- Genentech, South San Francisco, California, USA
| | - Michael Ford
- MS Bioworks, LLC, 3950, Varsity Drive, Ann Arbor, Michigan, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA.
- Department of Medicine, University of Chicago, Chicago, Illinois, USA.
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26
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Knowles DA, Burrows CK, Blischak JD, Patterson KM, Serie DJ, Norton N, Ober C, Pritchard JK, Gilad Y. Determining the genetic basis of anthracycline-cardiotoxicity by molecular response QTL mapping in induced cardiomyocytes. eLife 2018; 7:e33480. [PMID: 29737278 PMCID: PMC6010343 DOI: 10.7554/elife.33480] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 04/30/2018] [Indexed: 12/17/2022] Open
Abstract
Anthracycline-induced cardiotoxicity (ACT) is a key limiting factor in setting optimal chemotherapy regimes, with almost half of patients expected to develop congestive heart failure given high doses. However, the genetic basis of sensitivity to anthracyclines remains unclear. We created a panel of iPSC-derived cardiomyocytes from 45 individuals and performed RNA-seq after 24 hr exposure to varying doxorubicin dosages. The transcriptomic response is substantial: the majority of genes are differentially expressed and over 6000 genes show evidence of differential splicing, the later driven by reduced splicing fidelity in the presence of doxorubicin. We show that inter-individual variation in transcriptional response is predictive of in vitro cell damage, which in turn is associated with in vivo ACT risk. We detect 447 response-expression quantitative trait loci (QTLs) and 42 response-splicing QTLs, which are enriched in lower ACT GWAS [Formula: see text]-values, supporting the in vivo relevance of our map of genetic regulation of cellular response to anthracyclines.
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Affiliation(s)
- David A Knowles
- Department of GeneticsStanford UniversityStanfordUnited States
- Department of RadiologyStanford UniversityStanfordUnited States
| | | | - John D Blischak
- Department of Human GeneticsUniversity of ChicagoChicagoUnited States
| | | | - Daniel J Serie
- Department of Health Sciences ResearchMayo ClinicJacksonvilleUnited States
| | - Nadine Norton
- Department of Cancer BiologyMayo ClinicJacksonvilleUnited States
| | - Carole Ober
- Department of Human GeneticsUniversity of ChicagoChicagoUnited States
| | - Jonathan K Pritchard
- Department of GeneticsStanford UniversityStanfordUnited States
- Department of BiologyStanford UniversityStanfordUnited States
- Howard Hughes Medical InstituteStanford UniversityStanfordUnited States
| | - Yoav Gilad
- Department of Human GeneticsUniversity of ChicagoChicagoUnited States
- Department of MedicineUniversity of ChicagoChicagoUnited States
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27
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Ward MC, Zhao S, Luo K, Pavlovic BJ, Karimi MM, Stephens M, Gilad Y. Silencing of transposable elements may not be a major driver of regulatory evolution in primate iPSCs. eLife 2018; 7:33084. [PMID: 29648536 PMCID: PMC5943035 DOI: 10.7554/elife.33084] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 04/11/2018] [Indexed: 12/16/2022] Open
Abstract
Transposable elements (TEs) comprise almost half of primate genomes and their aberrant regulation can result in deleterious effects. In pluripotent stem cells, rapidly evolving KRAB-ZNF genes target TEs for silencing by H3K9me3. To investigate the evolution of TE silencing, we performed H3K9me3 ChIP-seq experiments in induced pluripotent stem cells from 10 human and 7 chimpanzee individuals. We identified four million orthologous TEs and found the SVA and ERV families to be marked most frequently by H3K9me3. We found little evidence of inter-species differences in TE silencing, with as many as 82% of putatively silenced TEs marked at similar levels in humans and chimpanzees. TEs that are preferentially silenced in one species are a similar age to those silenced in both species and are not more likely to be associated with expression divergence of nearby orthologous genes. Our data suggest limited species-specificity of TE silencing across 6 million years of primate evolution.
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Affiliation(s)
- Michelle C Ward
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Medicine, University of Chicago, Chicago, United States
| | - Siming Zhao
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Kaixuan Luo
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Bryan J Pavlovic
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Mohammad M Karimi
- MRC London Institute of Medical Sciences, Imperial College, London, United Kingdom
| | - Matthew Stephens
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Statistics, University of Chicago, Chicago, United States
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Medicine, University of Chicago, Chicago, United States
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28
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Banovich NE, Li YI, Raj A, Ward MC, Greenside P, Calderon D, Tung PY, Burnett JE, Myrthil M, Thomas SM, Burrows CK, Romero IG, Pavlovic BJ, Kundaje A, Pritchard JK, Gilad Y. Impact of regulatory variation across human iPSCs and differentiated cells. Genome Res 2017; 28:122-131. [PMID: 29208628 PMCID: PMC5749177 DOI: 10.1101/gr.224436.117] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 11/20/2017] [Indexed: 12/17/2022]
Abstract
Induced pluripotent stem cells (iPSCs) are an essential tool for studying cellular differentiation and cell types that are otherwise difficult to access. We investigated the use of iPSCs and iPSC-derived cells to study the impact of genetic variation on gene regulation across different cell types and as models for studies of complex disease. To do so, we established a panel of iPSCs from 58 well-studied Yoruba lymphoblastoid cell lines (LCLs); 14 of these lines were further differentiated into cardiomyocytes. We characterized regulatory variation across individuals and cell types by measuring gene expression levels, chromatin accessibility, and DNA methylation. Our analysis focused on a comparison of inter-individual regulatory variation across cell types. While most cell-type-specific regulatory quantitative trait loci (QTLs) lie in chromatin that is open only in the affected cell types, we found that 20% of cell-type-specific regulatory QTLs are in shared open chromatin. This observation motivated us to develop a deep neural network to predict open chromatin regions from DNA sequence alone. Using this approach, we were able to use the sequences of segregating haplotypes to predict the effects of common SNPs on cell-type-specific chromatin accessibility.
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Affiliation(s)
- Nicholas E Banovich
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Yang I Li
- Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Anil Raj
- Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Michelle C Ward
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA.,Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
| | - Peyton Greenside
- Department of Biomedical Informatics, Stanford University, Stanford, California 94305, USA
| | - Diego Calderon
- Department of Biomedical Informatics, Stanford University, Stanford, California 94305, USA
| | - Po Yuan Tung
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA.,Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
| | - Jonathan E Burnett
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Marsha Myrthil
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Samantha M Thomas
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Courtney K Burrows
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Irene Gallego Romero
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Bryan J Pavlovic
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Jonathan K Pritchard
- Department of Genetics, Stanford University, Stanford, California 94305, USA.,Department of Biology, Stanford University, Stanford, California 94305, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA.,Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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29
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Blischak JD, Tailleux L, Myrthil M, Charlois C, Bergot E, Dinh A, Morizot G, Chény O, Platen CV, Herrmann JL, Brosch R, Barreiro LB, Gilad Y. Predicting susceptibility to tuberculosis based on gene expression profiling in dendritic cells. Sci Rep 2017; 7:5702. [PMID: 28720766 PMCID: PMC5516010 DOI: 10.1038/s41598-017-05878-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 06/05/2017] [Indexed: 01/11/2023] Open
Abstract
Tuberculosis (TB) is a deadly infectious disease, which kills millions of people every year. The causative pathogen, Mycobacterium tuberculosis (MTB), is estimated to have infected up to a third of the world's population; however, only approximately 10% of infected healthy individuals progress to active TB. Despite evidence for heritability, it is not currently possible to predict who may develop TB. To explore approaches to classify susceptibility to TB, we infected with MTB dendritic cells (DCs) from putatively resistant individuals diagnosed with latent TB, and from susceptible individuals that had recovered from active TB. We measured gene expression levels in infected and non-infected cells and found hundreds of differentially expressed genes between susceptible and resistant individuals in the non-infected cells. We further found that genetic polymorphisms nearby the differentially expressed genes between susceptible and resistant individuals are more likely to be associated with TB susceptibility in published GWAS data. Lastly, we trained a classifier based on the gene expression levels in the non-infected cells, and demonstrated reasonable performance on our data and an independent data set. Overall, our promising results from this small study suggest that training a classifier on a larger cohort may enable us to accurately predict TB susceptibility.
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Affiliation(s)
- John D Blischak
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, Illinois, USA
| | - Ludovic Tailleux
- Integrated Mycobacterial Pathogenomics, Institut Pasteur, Paris, France.
| | - Marsha Myrthil
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Cécile Charlois
- Centre de Lutte Antituberculeuse de Paris, DASES Mairie de Paris, 75013, Paris, France
| | - Emmanuel Bergot
- Service de pneumologie et oncologie thoracique, CHU Côte de Nacre, 14033, Caen, France
| | - Aurélien Dinh
- Maladies Infectieuses, AP-HP, Hôpital Universitaire Raymond-Poincaré, Garches, 92380, France
| | - Gloria Morizot
- Clinical Investigation & Access Biological Resources (ICAReB), Institut Pasteur, Paris, France
| | - Olivia Chény
- Clinical Core, Centre for Translational Science, Institut Pasteur, Paris, France
| | - Cassandre Von Platen
- Clinical Core, Centre for Translational Science, Institut Pasteur, Paris, France
| | - Jean-Louis Herrmann
- INSERM, U1173, UFR Simone Veil, Université de Versailles Saint Quentin, Saint Quentin en Yvelines, France
- APHP, Groupe Hospitalo-Universitaire Paris Île-de-France Ouest, Garches et Boulogne-Billancourt, France
| | - Roland Brosch
- Integrated Mycobacterial Pathogenomics, Institut Pasteur, Paris, France
| | - Luis B Barreiro
- Department of Genetics, CHU Sainte-Justine Research Center, Montreal, Québec, Canada.
- Department of Pediatrics, University of Montreal, Montreal, Québec, Canada.
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA.
- Department of Medicine, University of Chicago, Chicago, Illinois, USA.
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30
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Gilad Y, Tuchinsky H, Ben-David G, Minnes R, Gancz A, Senderowitz H, Luboshits G, Firer MA, Gellerman G. Discovery of potent molecular chimera (CM358) to treat human metastatic melanoma. Eur J Med Chem 2017; 138:602-615. [PMID: 28710962 DOI: 10.1016/j.ejmech.2017.06.066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/26/2017] [Accepted: 06/28/2017] [Indexed: 11/18/2022]
Abstract
The resistance of cancer cells to chemotherapeutic agents, whether through intrinsic mechanisms or developed resistance, motivates the search for new chemotherapeutic strategies. In the present report, we demonstrate a facile synthetic strategy towards the discovery of new anti-cancer substances. This strategy is based on simple covalent coupling between known anti-cancer drugs, which results in novel 'chimeric' small molecules. One of these novel compounds, CM358, is the product of an amide bond formation between the known Topoisomerase II (Topo II) inhibitor amonafide (AM) and the known DNA mustard alkylator chlorambucil (CLB). It demonstrates significant enhanced cytotoxicity over an equimolar mixture of AM and CLB in various cancer cell lines and in a xenograft model of human metastatic melanoma. Topo II inhibition as well as in silico docking studies suggest that CM358 is a stronger Topo II binder than AM. This may be attributed, at least partially, to the placement of the CLB moiety in a favorable orientation with respect to DNA cross-linking with nearby guanines. In a human metastatic melanoma (WM 266-4) xenograft model, this compound was profoundly superior to a mixture of AM and CLB in reduction of tumor growth, maintenance of body weight and extension of overall survival.
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MESH Headings
- Animals
- Antineoplastic Agents/chemical synthesis
- Antineoplastic Agents/chemistry
- Antineoplastic Agents/pharmacology
- Cell Proliferation/drug effects
- DNA Topoisomerases, Type II/metabolism
- Dose-Response Relationship, Drug
- Drug Discovery
- Drug Screening Assays, Antitumor
- Heterocyclic Compounds, 3-Ring/chemical synthesis
- Heterocyclic Compounds, 3-Ring/chemistry
- Heterocyclic Compounds, 3-Ring/pharmacology
- Humans
- Melanoma/drug therapy
- Melanoma/pathology
- Mice
- Mice, Nude
- Models, Molecular
- Molecular Structure
- Neoplasms, Experimental/drug therapy
- Neoplasms, Experimental/pathology
- Pyrimidinones/chemical synthesis
- Pyrimidinones/chemistry
- Pyrimidinones/pharmacology
- Structure-Activity Relationship
- Topoisomerase II Inhibitors/chemical synthesis
- Topoisomerase II Inhibitors/chemistry
- Topoisomerase II Inhibitors/pharmacology
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Affiliation(s)
- Y Gilad
- Department of Chemical Sciences, Ariel University, Ariel, 40700, Israel
| | - H Tuchinsky
- Department of Molecular Biology, Ariel University, Ariel, 40700, Israel
| | - G Ben-David
- Department of Chemistry, Bar Ilan University, Ramat Gan, 5290002, Israel
| | - R Minnes
- Department of Physics, Ariel University, Ariel, 40700, Israel
| | - A Gancz
- Department of Molecular Biology, Ariel University, Ariel, 40700, Israel
| | - H Senderowitz
- Department of Chemistry, Bar Ilan University, Ramat Gan, 5290002, Israel
| | - G Luboshits
- Department of Chemical Engineering, Ariel University, Ariel, 40700, Israel
| | - M A Firer
- Department of Chemical Engineering, Ariel University, Ariel, 40700, Israel
| | - G Gellerman
- Department of Chemical Sciences, Ariel University, Ariel, 40700, Israel.
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31
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Igartua C, Davenport ER, Gilad Y, Nicolae DL, Pinto J, Ober C. Host genetic variation in mucosal immunity pathways influences the upper airway microbiome. Microbiome 2017; 5:16. [PMID: 28143570 PMCID: PMC5286564 DOI: 10.1186/s40168-016-0227-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 12/25/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND The degree to which host genetic variation can modulate microbial communities in humans remains an open question. Here, we performed a genetic mapping study of the microbiome in two accessible upper airway sites, the nasopharynx and the nasal vestibule, during two seasons in 144 adult members of a founder population of European decent. RESULTS We estimated the relative abundances (RAs) of genus level bacteria from 16S rRNA gene sequences and examined associations with 148,653 genetic variants (linkage disequilibrium [LD] r 2 < 0.5) selected from among all common variants discovered in genome sequences in this population. We identified 37 microbiome quantitative trait loci (mbQTLs) that showed evidence of association with the RAs of 22 genera (q < 0.05) and were enriched for genes in mucosal immunity pathways. The most significant association was between the RA of Dermacoccus (phylum Actinobacteria) and a variant 8 kb upstream of TINCR (rs117042385; p = 1.61 × 10-8; q = 0.002), a long non-coding RNA that binds to peptidoglycan recognition protein 3 (PGLYRP3) mRNA, a gene encoding a known antimicrobial protein. A second association was between a missense variant in PGLYRP4 (rs3006458) and the RA of an unclassified genus of family Micrococcaceae (phylum Actinobacteria) (p = 5.10 × 10-7; q = 0.032). CONCLUSIONS Our findings provide evidence of host genetic influences on upper airway microbial composition in humans and implicate mucosal immunity genes in this relationship.
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Affiliation(s)
- Catherine Igartua
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA.
| | - Emily R Davenport
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
- Department of Medicine, University of Chicago, Chicago, IL, 60637, USA
| | - Dan L Nicolae
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
- Department of Medicine, University of Chicago, Chicago, IL, 60637, USA
- Department of Statistics, University of Chicago, Chicago, IL, 60637, USA
| | - Jayant Pinto
- Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Chicago, Chicago, IL, 60637, USA
| | - Carole Ober
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA.
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32
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Bainer R, Frankenberger C, Rabe D, An G, Gilad Y, Rosner MR. Gene expression in local stroma reflects breast tumor states and predicts patient outcome. Sci Rep 2016; 6:39240. [PMID: 27982086 PMCID: PMC5159815 DOI: 10.1038/srep39240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/21/2016] [Indexed: 02/04/2023] Open
Abstract
The surrounding microenvironment has been implicated in the progression of breast tumors to metastasis. However, the degree to which metastatic breast tumors locally reprogram stromal cells as they disrupt tissue boundaries is not well understood. We used species-specific RNA sequencing in a mouse xenograft model to determine how the metastasis suppressor RKIP influences transcription in a panel of paired tumor and stroma tissues. We find that gene expression in metastatic breast tumors is pervasively correlated with gene expression in local stroma of both mouse xenografts and human patients. Changes in stromal gene expression elicited by tumors better predicts subtype and patient survival than tumor gene expression, and genes with coordinated expression in both tissues predict metastasis-free survival. These observations support the use of stroma-based strategies for the diagnosis and prognosis of breast cancer.
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Affiliation(s)
- Russell Bainer
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Casey Frankenberger
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Daniel Rabe
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Gary An
- Department of Surgery, University of Chicago, Chicago, IL 60637, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Marsha Rich Rosner
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
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33
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Nicodemus-Johnson J, Myers RA, Sakabe NJ, Sobreira DR, Hogarth DK, Naureckas ET, Sperling AI, Solway J, White SR, Nobrega MA, Nicolae DL, Gilad Y, Ober C. DNA methylation in lung cells is associated with asthma endotypes and genetic risk. JCI Insight 2016; 1:e90151. [PMID: 27942592 DOI: 10.1172/jci.insight.90151] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The epigenome provides a substrate through which environmental exposures can exert their effects on gene expression and disease risk, but the relative importance of epigenetic variation on human disease onset and progression is poorly characterized. Asthma is a heterogeneous disease of the airways, for which both onset and clinical course result from interactions between host genotype and environmental exposures, yet little is known about the molecular mechanisms for these interactions. We assessed genome-wide DNA methylation using the Infinium Human Methylation 450K Bead Chip and characterized the transcriptome by RNA sequencing in primary airway epithelial cells from 74 asthmatic and 41 nonasthmatic adults. Asthma status was based on doctor's diagnosis and current medication use. Genotyping was performed using various Illumina platforms. Our study revealed a regulatory locus on chromosome 17q12-21 associated with asthma risk and epigenetic signatures of specific asthma endotypes and molecular networks. Overall, these data support a central role for DNA methylation in lung cells, which promotes distinct molecular pathways of asthma pathogenesis and modulates the effects of genetic variation on disease risk and clinical heterogeneity.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Dan L Nicolae
- Department of Human Genetics.,Department of Medicine, and.,Department of Statistics, University of Chicago, Chicago, Illinois, USA
| | - Yoav Gilad
- Department of Human Genetics.,Department of Medicine, and
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34
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Olender T, Keydar I, Pinto JM, Tatarskyy P, Alkelai A, Chien MS, Fishilevich S, Restrepo D, Matsunami H, Gilad Y, Lancet D. The human olfactory transcriptome. BMC Genomics 2016; 17:619. [PMID: 27515280 PMCID: PMC4982115 DOI: 10.1186/s12864-016-2960-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 07/21/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Olfaction is a versatile sensory mechanism for detecting thousands of volatile odorants. Although molecular basis of odorant signaling is relatively well understood considerable gaps remain in the complete charting of all relevant gene products. To address this challenge, we applied RNAseq to four well-characterized human olfactory epithelial samples and compared the results to novel and published mouse olfactory epithelium as well as 16 human control tissues. RESULTS We identified 194 non-olfactory receptor (OR) genes that are overexpressed in human olfactory tissues vs. CONTROLS The highest overexpression is seen for lipocalins and bactericidal/permeability-increasing (BPI)-fold proteins, which in other species include secreted odorant carriers. Mouse-human discordance in orthologous lipocalin expression suggests different mammalian evolutionary paths in this family. Of the overexpressed genes 36 have documented olfactory function while for 158 there is little or no previous such functional evidence. The latter group includes GPCRs, neuropeptides, solute carriers, transcription factors and biotransformation enzymes. Many of them may be indirectly implicated in sensory function, and ~70 % are over expressed also in mouse olfactory epithelium, corroborating their olfactory role. Nearly 90 % of the intact OR repertoire, and ~60 % of the OR pseudogenes are expressed in the olfactory epithelium, with the latter showing a 3-fold lower expression. ORs transcription levels show a 1000-fold inter-paralog variation, as well as significant inter-individual differences. We assembled 160 transcripts representing 100 intact OR genes. These include 1-4 short 5' non-coding exons with considerable alternative splicing and long last exons that contain the coding region and 3' untranslated region of highly variable length. Notably, we identified 10 ORs with an intact open reading frame but with seemingly non-functional transcripts, suggesting a yet unreported OR pseudogenization mechanism. Analysis of the OR upstream regions indicated an enrichment of the homeobox family transcription factor binding sites and a consensus localization of a specific transcription factor binding site subfamily (Olf/EBF). CONCLUSIONS We provide an overview of expression levels of ORs and auxiliary genes in human olfactory epithelium. This forms a transcriptomic view of the entire OR repertoire, and reveals a large number of over-expressed uncharacterized human non-receptor genes, providing a platform for future discovery.
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Affiliation(s)
- Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
| | - Ifat Keydar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Jayant M Pinto
- Section of Otolaryngology-Head and Neck Surgery, University of Chicago, Chicago, IL, USA
| | - Pavlo Tatarskyy
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Anna Alkelai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ming-Shan Chien
- Department of Molecular Genetics and Microbiology, Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
| | - Simon Fishilevich
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Diego Restrepo
- Department of Cell and Developmental Biology, Neuroscience Program, and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, CO, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Doron Lancet
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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35
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Rabe DC, Frankenberger C, Bainer R, Sankarasharma D, Chada K, Krausz T, Gilad Y, Becker L, Rosner MR. Abstract 1557: Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of prometastatic TAMs. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-1557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Triple-negative breast cancer (TNBC) patients have the highest risk of recurrence and metastasis. Because they cannot be treated with targeted therapies, and many do not respond to chemotherapy, they represent a clinically underserved group. While physiological inhibitors of metastasis (metastasis suppressors) play key roles in regulating tumor growth, invasion and metastasis, their role in regulating the tumor microenvironment and immune system is unknown. We hypothesized that the metastasis suppressor Raf Kinase Inhibitory Protein (RKIP) regulates stromal cells, which then affect tumor invasiveness.
Using species-specific RNAseq we determined that expression of RKIP in tumors markedly reduces the number and metastatic potential of infiltrating TAMs. While TAMs isolated from TNBC xenografts drive in vitro invasion, RKIP+ derived TAMs did not drive invasion and had decreased secretion of pro-metastatic factors including SLPI, OPN, MMP-12, Galectin-3, VEGF-A, VEGF-D, TNFR2, and PGRN. We determined that RKIP regulates TAM recruitment by blocking HMGA2, which activates CCL5 expression. CCL5 rescued pro-metastatic TAM infiltration as well as tumor intravasation. We additionally showed that factors decreased in RKIP-derived TAMs were restored in CCL5-derived TAMs. CCL5 derived TAMs were also able to promote metastasis when co-injected with MDA-MB-231 tumors. These tumor cells demonstrated permanent increases in both growth and invasive potential after co-injection with highly pro-metastatic CCL5 derived TAMs.
To determine the clinical utility of these TAM genes we combined their expression with RKIP signaling in the tumor to create a signature that strikingly separates TNBC patients based on outcome. Our results demonstrate for the first time that metastasis suppressors can regulate the microenvironment, regulating invasion through TAMs. Our results also suggest aggressive triple negative breast cancers could be controlled by attacking CCL5 derived TAMs crucial for promoting metastasis.
Funded by: GM087630, CA184494, and CA192780
Citation Format: Daniel C. Rabe, Casey Frankenberger, Russell Bainer, Devipriya Sankarasharma, Kiran Chada, Thomas Krausz, Yoav Gilad, Lev Becker, Marsha R. Rosner. Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of prometastatic TAMs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1557.
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Raj A, Wang SH, Shim H, Harpak A, Li YI, Engelmann B, Stephens M, Gilad Y, Pritchard JK. Thousands of novel translated open reading frames in humans inferred by ribosome footprint profiling. eLife 2016; 5. [PMID: 27232982 PMCID: PMC4940163 DOI: 10.7554/elife.13328] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 05/26/2016] [Indexed: 01/19/2023] Open
Abstract
Accurate annotation of protein coding regions is essential for understanding how genetic information is translated into function. We describe riboHMM, a new method that uses ribosome footprint data to accurately infer translated sequences. Applying riboHMM to human lymphoblastoid cell lines, we identified 7273 novel coding sequences, including 2442 translated upstream open reading frames. We observed an enrichment of footprints at inferred initiation sites after drug-induced arrest of translation initiation, validating many of the novel coding sequences. The novel proteins exhibit significant selective constraint in the inferred reading frames, suggesting that many are functional. Moreover, ~40% of bicistronic transcripts showed negative correlation in the translation levels of their two coding sequences, suggesting a potential regulatory role for these novel regions. Despite known limitations of mass spectrometry to detect protein expressed at low level, we estimated a 14% validation rate. Our work significantly expands the set of known coding regions in humans. DOI:http://dx.doi.org/10.7554/eLife.13328.001
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Affiliation(s)
- Anil Raj
- Department of Genetics, Stanford University, Stanford, United States
| | - Sidney H Wang
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Heejung Shim
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Arbel Harpak
- Department of Biology, Stanford University, Stanford, United States
| | - Yang I Li
- Department of Genetics, Stanford University, Stanford, United States
| | - Brett Engelmann
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Matthew Stephens
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Statistics, University of Chicago, Chicago, United States
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Jonathan K Pritchard
- Department of Genetics, Stanford University, Stanford, United States.,Department of Biology, Stanford University, Stanford, United States.,Howard Hughes Medical Institute, Stanford University, Stanford, United States
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Li YI, van de Geijn B, Raj A, Knowles DA, Petti AA, Golan D, Gilad Y, Pritchard JK. RNA splicing is a primary link between genetic variation and disease. Science 2016; 352:600-4. [PMID: 27126046 DOI: 10.1126/science.aad9417] [Citation(s) in RCA: 378] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/25/2016] [Indexed: 12/14/2022]
Abstract
Noncoding variants play a central role in the genetics of complex traits, but we still lack a full understanding of the molecular pathways through which they act. We quantified the contribution of cis-acting genetic effects at all major stages of gene regulation from chromatin to proteins, in Yoruba lymphoblastoid cell lines (LCLs). About ~65% of expression quantitative trait loci (eQTLs) have primary effects on chromatin, whereas the remaining eQTLs are enriched in transcribed regions. Using a novel method, we also detected 2893 splicing QTLs, most of which have little or no effect on gene-level expression. These splicing QTLs are major contributors to complex traits, roughly on a par with variants that affect gene expression levels. Our study provides a comprehensive view of the mechanisms linking genetic variation to variation in human gene regulation.
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Affiliation(s)
- Yang I Li
- Department of Genetics, Stanford University, Stanford, CA, USA
| | | | - Anil Raj
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - David A Knowles
- Department of Computer Science, Stanford University, Stanford, CA, USA. Department of Radiology, Stanford University, Stanford, CA, USA
| | - Allegra A Petti
- Genome Institute, Washington University in St. Louis, St. Louis, MO, USA
| | - David Golan
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL, USA.
| | - Jonathan K Pritchard
- Department of Genetics, Stanford University, Stanford, CA, USA. Department of Biology, Stanford University, Stanford, CA, USA. Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.
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Rabe DC, Frankenberger C, Bainer R, Sankarasharma D, Chada K, Krausz T, Gilad Y, Becker L, Rosner MR. Abstract A01: Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of pro-metastatic tumor-associated macrophages. Cancer Res 2016. [DOI: 10.1158/1538-7445.tummet15-a01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
This abstract is being presented as a short talk in the scientific program. A full abstract is printed in the Proffered Abstracts section (PR02) of the Conference Proceedings.
Citation Format: Daniel C. Rabe, Casey Frankenberger, Russell Bainer, Devipriya Sankarasharma, Kiran Chada, Thomas Krausz, Yoav Gilad, Lev Becker, Marsha Rich Rosner. Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of pro-metastatic tumor-associated macrophages. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr A01.
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Rabe DC, Frankenberger C, Bainer R, Sankarasharma D, Chada K, Krausz T, Gilad Y, Becker L, Rosner MR. Abstract PR02: Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of pro-metastatic tumor-associated macrophages. Cancer Res 2016. [DOI: 10.1158/1538-7445.tummet15-pr02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Triple-negative breast cancer (TNBC) patients have the highest risk of recurrence and metastasis. Because they cannot be treated with targeted therapies, and many do not respond to chemotherapy, they represent a clinically underserved group. While physiological inhibitors of metastasis (metastasis suppressors) play key roles in regulating tumor growth, invasion and metastasis, their role in regulating the tumor microenvironment and immune system is unknown. We hypothesized that the metastasis suppressor Raf Kinase Inhibitory Protein (RKIP) regulates stromal cells, which then affect tumor invasiveness.
Using species-specific RNAseq we determined that expression of RKIP in tumors markedly reduces the number and metastatic potential of infiltrating TAMs. While TAMs isolated from TNBC xenografts drive in vitro invasion, RKIP+ derived TAMs did not drive invasion and had decreased secretion of pro-metastatic factors including SLPI, OPN, MMP-12, Galectin-3, VEGF-A, VEGF-D, TNFR2, and PGRN. We determined that RKIP regulates TAM recruitment by blocking HMGA2, which activates CCL5 expression. CCL5 rescued pro-metastatic TAM infiltration as well as tumor intravasation. We additionally showed that factors decreased in RKIP-derived TAMs were restored in CCL5-derived TAMs. CCL5 derived TAMs were also able to promote metastasis when co-injected with MDA-MB-231 tumors. These tumor cells demonstrated permanent increases in both growth and invasive potential after co-injection with highly pro-metastatic CCL5 derived TAMs.
To determine the clinical utility of these TAM genes we combined their expression with RKIP signaling in the tumor to create a signature that strikingly separates TNBC patients based on outcome. Our results demonstrate for the first time that metastasis suppressors can regulate the microenvironment, regulating invasion through TAMs. Our results also suggest aggressive triple negative breast cancers could be controlled by attacking CCL5 derived TAMs crucial for promoting metastasis.
Citation Format: Daniel C. Rabe, Casey Frankenberger, Russell Bainer, Devipriya Sankarasharma, Kiran Chada, Thomas Krausz, Yoav Gilad, Lev Becker, Marsha Rich Rosner. Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of pro-metastatic tumor-associated macrophages. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr PR02.
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Gilad Y, Noy E, Senderowitz H, Albeck A, Firer MA, Gellerman G. Dual-drug RGD conjugates provide enhanced cytotoxicity to melanoma and non-small lung cancer cells. Biopolymers 2016; 106:160-171. [PMID: 26715008 DOI: 10.1002/bip.22800] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/02/2015] [Accepted: 12/18/2015] [Indexed: 01/22/2023]
Abstract
To enhance the efficacy of targeted drug delivery, four new peptide-ligand conjugates were synthesized, each consisting of a cyclic RGDfK penta-peptide loaded with two anticancer drugs. The drug release profiles in different media of these new compounds and their cytotoxic activity against melanoma and non-small lung cancer cell lines were evaluated and compared with those of their singly loaded analogs. The cyclic RGDfK penta-peptide was selected as a targeting moiety because of its high affinity and selectivity to the αv β3 integrin receptor, which is frequently over-expressed in various types of cancer cells. The peptide's core was modified at the side chain of its Lys residue by coupling it with a sixth amino acid (AA) - either Lys (5a) or Ser (5b) (Lys/Ser splitter), resulting in two functional sites which enabled the loading of two therapeutic equivalents onto a single targeting carrier. Using Lys as a splitter resulted in two primary amines. Consequently, conjugates 1a and 1b were synthesized by coupling of 2 Chlorambucils (CLBs) or 2 Camptothecins (CPTs), respectively, to the primary amines of 5a. Conjugate 1c was synthesized from 5b by loading two equivalents of CLB on the amine and the hydroxyl of the Ser splitter, resulting in a homodimeric system with two distinct conjugation sites - amide and ester. The heterodimeric conjugate 1d of CLB and CPT was synthesized by loading each one of the primary amines of 5a with two different drugs - CLB and CPT. The doubling of drug equivalents loaded onto the targeting peptide correlated with enhanced cytotoxic efficacy of the conjugates towards cancer cells. The versatility of chemical linkages of the drugs to the peptides resulted in conjugates with different drug release profiles. Molecular dynamics simulations performed on conjugate 1d demonstrated that this compound occupies a conformational space similar to the bio-active conformation of an integrin-bound cyclic RGD peptide reference peptide (c(RGDf(NMe)V). The modified position in 1d (relative to the reference peptide) points away from the integrin, leading us to hypothesize that this peptide binds the integrin in a manner similar to that of the reference peptide thereby fulfilling a crucial requirement for targeted delivery. The strategy of dual drug loading on a single peptide carrier, gives rise to drugs with different mechanisms of action and release profiles, thus substantially increasing the efficacy of selective killing of tumor cells and while reducing the risk of the development of drug resistance. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 160-171, 2016.
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Affiliation(s)
- Y Gilad
- Department of Biological Chemistry, Ariel University, Ariel, 40700, Israel.,The Julius Spokojny Bioorganic Chemistry Laboratory, Department of Chemistry, Bar Ilan University, Ramat Gan, 52900, Israel
| | - E Noy
- Department of Chemistry, Bar Ilan University, Ramat Gan, 52900, Israel
| | - H Senderowitz
- Department of Chemistry, Bar Ilan University, Ramat Gan, 52900, Israel
| | - A Albeck
- The Julius Spokojny Bioorganic Chemistry Laboratory, Department of Chemistry, Bar Ilan University, Ramat Gan, 52900, Israel
| | - M A Firer
- Department of Chemical Engineering, Ariel University, Ariel, 40700, Israel
| | - G Gellerman
- Department of Biological Chemistry, Ariel University, Ariel, 40700, Israel
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41
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Cusanovich DA, Caliskan M, Billstrand C, Michelini K, Chavarria C, De Leon S, Mitrano A, Lewellyn N, Elias JA, Chupp GL, Lang RM, Shah SJ, Decara JM, Gilad Y, Ober C. Integrated analyses of gene expression and genetic association studies in a founder population. Hum Mol Genet 2016; 25:2104-2112. [PMID: 26931462 PMCID: PMC5062579 DOI: 10.1093/hmg/ddw061] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 02/21/2016] [Indexed: 12/17/2022] Open
Abstract
Genome-wide association studies (GWASs) have become a standard tool for dissecting genetic contributions to disease risk. However, these studies typically require extraordinarily large sample sizes to be adequately powered. Strategies that incorporate functional information alongside genetic associations have proved successful in increasing GWAS power. Following this paradigm, we present the results of 20 different genetic association studies for quantitative traits related to complex diseases, conducted in the Hutterites of South Dakota. To boost the power of these association studies, we collected RNA-sequencing data from lymphoblastoid cell lines for 431 Hutterite individuals. We then used Sherlock, a tool that integrates GWAS and expression quantitative trait locus (eQTL) data, to identify weak GWAS signals that are also supported by eQTL data. Using this approach, we found novel associations with quantitative phenotypes related to cardiovascular disease, including carotid intima-media thickness, left atrial volume index, monocyte count and serum YKL-40 levels.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Jack A Elias
- Division of Biology and Medicine, Brown University, Providence, RI 02912, USA and
| | - Geoffrey L Chupp
- Pulmonary and Critical Care, Yale School of Medicine, New Haven, CT 06519, USA
| | - Roberto M Lang
- Department of Medicine, Section of Cardiology, University of Chicago, Chicago, IL 60637, USA
| | - Sanjiv J Shah
- Department of Medicine, Section of Cardiology, University of Chicago, Chicago, IL 60637, USA
| | - Jeanne M Decara
- Department of Medicine, Section of Cardiology, University of Chicago, Chicago, IL 60637, USA
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42
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Burrows CK, Banovich NE, Pavlovic BJ, Patterson K, Gallego Romero I, Pritchard JK, Gilad Y. Genetic Variation, Not Cell Type of Origin, Underlies the Majority of Identifiable Regulatory Differences in iPSCs. PLoS Genet 2016; 12:e1005793. [PMID: 26812582 PMCID: PMC4727884 DOI: 10.1371/journal.pgen.1005793] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023] Open
Abstract
The advent of induced pluripotent stem cells (iPSCs) revolutionized human genetics by allowing us to generate pluripotent cells from easily accessible somatic tissues. This technology can have immense implications for regenerative medicine, but iPSCs also represent a paradigm shift in the study of complex human phenotypes, including gene regulation and disease. Yet, an unresolved caveat of the iPSC model system is the extent to which reprogrammed iPSCs retain residual phenotypes from their precursor somatic cells. To directly address this issue, we used an effective study design to compare regulatory phenotypes between iPSCs derived from two types of commonly used somatic precursor cells. We find a remarkably small number of differences in DNA methylation and gene expression levels between iPSCs derived from different somatic precursors. Instead, we demonstrate genetic variation is associated with the majority of identifiable variation in DNA methylation and gene expression levels. We show that the cell type of origin only minimally affects gene expression levels and DNA methylation in iPSCs, and that genetic variation is the main driver of regulatory differences between iPSCs of different donors. Our findings suggest that studies using iPSCs should focus on additional individuals rather than clones from the same individual. Induced pluripotent stem cells (iPSCs) are a new and powerful cell type that provides scientists the ability to model complex human diseases in vitro. These cells can be cryopreserved and later expanded, providing a renewable source of cells from the same individual. iPSCs can be made from a variety of somatic cells in the body and many labs have created them from blood and skin cells. We asked whether the cell type of origin impacts methylation and gene expression patterns in the reprogrammed iPSCs. Our findings indicate that there are remarkably few regulatory remnants of the cell type of origin in the iPSCs. In other words, most of the variation between iPSCs can be attributed to individual genetics. Our findings suggest that studies using iPSCs should focus on obtaining additional individuals rather than additional clones from the same individual. We caution that our current findings are limited to iPSCs and further studies are needed to address the question of somatic memory in differentiated cell types.
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Affiliation(s)
- Courtney K. Burrows
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Nicholas E. Banovich
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Bryan J. Pavlovic
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Kristen Patterson
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Irene Gallego Romero
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Jonathan K. Pritchard
- Howard Hughes Medical Institute, Stanford University, Stanford, California, United States of America
- Departments of Genetics and Biology, Stanford University, Stanford, California, United States of America
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Lee J, Bainer R, Frankenberger C, Rabe D, Saleh S, Park M, An G, Gilad Y, Rosner MR. Abstract B15: Metastatic breast tumors regulate gene expression at distal mammary sites that predicts patient outcome. Mol Cancer Res 2016. [DOI: 10.1158/1557-3125.metca15-b15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The molecular interactions between cancer and stromal cells within the tumor microenvironment enable tumor invasion, intravasation, and metastasis at distant sites. However, the degree to which metastatic breast tumors reprogram stromal cells both locally and at distant mammary tissues is not well understood. To address this question, we used species-specific RNA sequencing in a mouse xenograft model to determine how the metastasis suppressor RKIP influences transcription in tumor and stroma tissues. Here we show that metastatic tumors prime mammary tissue at a distant site in a manner that reflects local stromal responses. In addition, gene expression in metastatic breast tumors is pervasively correlated with gene expression in local stroma of both mouse xenografts and human patients. Changes in local and distant stromal gene expression elicited by metastatic tumors are better predictors of subtype and patient survival than tumor gene expression, supporting the use of stromal-based strategies for the diagnosis and prognosis of breast cancer. One mechanism by which changes at contralateral distal mammary breast occur is through exosomes secreted by tumor cells. These results indicate that tumors prime contralateral mammary tissue in a manner that reflects local stromal changes and predicts metastatic disease. This study has future application to our understanding of contralateral breast cancer.
Citation Format: Jiyoung Lee, Russell Bainer, Casey Frankenberger, Daniel Rabe, sadiq Saleh, Morag Park, Gary An, Yoav Gilad, Marsha Rich Rosner. Metastatic breast tumors regulate gene expression at distal mammary sites that predicts patient outcome. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B15.
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Affiliation(s)
| | | | | | | | | | - Morag Park
- 2McGill University, Montreal, QC, Canada
| | - Gary An
- 1University of Chicago, Chicago, IL,
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Gilad Y, Noy E, Senderowitz H, Albeck A, Firer MA, Gellerman G. Synthesis, biological studies and molecular dynamics of new anticancer RGD-based peptide conjugates for targeted drug delivery. Bioorg Med Chem 2015; 24:294-303. [PMID: 26719208 DOI: 10.1016/j.bmc.2015.12.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 12/07/2015] [Accepted: 12/11/2015] [Indexed: 01/22/2023]
Abstract
New cyclic RGD peptide-anticancer agent conjugates, with different chemical functionalities attached to the parent peptide were synthesized in order to evaluate their biological activities and to provide a comparative study of their drug release profiles. The Integrin binding c(RGDfK) penta-peptide was used for the synthesis of Camptothecin (CPT) carbamate and Chlorambucil (CLB) amide conjugates. Substitution of the amino acid Lys with Ser resulted in a modified c(RGDfS) with a new attachment site, which enabled the synthesis of an ester CLB conjugate. Functional versatility of the conjugates was reflected in the variability of their drug release profiles, while the conserved RGD sequence of a selective binding to the αv integrin family, likely preserved their recognition by the Integrin and consequently their favorable toxicity towards targeted cancer cells. This hypothesis was supported by a computational analysis suggesting that all conjugates occupy conformational spaces similar to that of the Integrin bound bio-active parent peptide.
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Affiliation(s)
- Y Gilad
- Department of Biological Chemistry, Ariel University, Ariel 40700, Israel; The Julius Spokojny Bioorganic Chemistry Laboratory, Department of Chemistry, Bar Ilan University, Ramat Gan 52900, Israel
| | - E Noy
- Department of Chemistry, Bar Ilan University, Ramat Gan 52900, Israel
| | - H Senderowitz
- Department of Chemistry, Bar Ilan University, Ramat Gan 52900, Israel
| | - A Albeck
- The Julius Spokojny Bioorganic Chemistry Laboratory, Department of Chemistry, Bar Ilan University, Ramat Gan 52900, Israel
| | - M A Firer
- Department of Chemical Engineering, Ariel University, Ariel 40700, Israel
| | - G Gellerman
- Department of Biological Chemistry, Ariel University, Ariel 40700, Israel.
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45
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Blischak JD, Tailleux L, Mitrano A, Barreiro LB, Gilad Y. Mycobacterial infection induces a specific human innate immune response. Sci Rep 2015; 5:16882. [PMID: 26586179 PMCID: PMC4653619 DOI: 10.1038/srep16882] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/21/2015] [Indexed: 12/30/2022] Open
Abstract
The innate immune system provides the first response to infection and is now recognized to be partially pathogen-specific. Mycobacterium tuberculosis (MTB) is able to subvert the innate immune response and survive inside macrophages. Curiously, only 5-10% of otherwise healthy individuals infected with MTB develop active tuberculosis (TB). We do not yet understand the genetic basis underlying this individual-specific susceptibility. Moreover, we still do not know which properties of the innate immune response are specific to MTB infection. To identify immune responses that are specific to MTB, we infected macrophages with eight different bacteria, including different MTB strains and related mycobacteria, and studied their transcriptional response. We identified a novel subset of genes whose regulation was affected specifically by infection with mycobacteria. This subset includes genes involved in phagosome maturation, superoxide production, response to vitamin D, macrophage chemotaxis, and sialic acid synthesis. We suggest that genetic variants that affect the function or regulation of these genes should be considered candidate loci for explaining TB susceptibility.
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Affiliation(s)
- John D Blischak
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA.,Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, Illinois, USA
| | | | - Amy Mitrano
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Luis B Barreiro
- Department of Genetics, CHU Sainte-Justine Research Center, Montreal, Québec, Canada.,Department of Pediatrics, University of Montreal, Montreal, Québec, Canada
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
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46
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Raj A, Shim H, Gilad Y, Pritchard JK, Stephens M. msCentipede: Modeling Heterogeneity across Genomic Sites and Replicates Improves Accuracy in the Inference of Transcription Factor Binding. PLoS One 2015; 10:e0138030. [PMID: 26406244 PMCID: PMC4583425 DOI: 10.1371/journal.pone.0138030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/24/2015] [Indexed: 11/19/2022] Open
Abstract
Understanding global gene regulation depends critically on accurate annotation of regulatory elements that are functional in a given cell type. CENTIPEDE, a powerful, probabilistic framework for identifying transcription factor binding sites from tissue-specific DNase I cleavage patterns and genomic sequence content, leverages the hypersensitivity of factor-bound chromatin and the information in the DNase I spatial cleavage profile characteristic of each DNA binding protein to accurately infer functional factor binding sites. However, the model for the spatial profile in this framework fails to account for the substantial variation in the DNase I cleavage profiles across different binding sites. Neither does it account for variation in the profiles at the same binding site across multiple replicate DNase I experiments, which are increasingly available. In this work, we introduce new methods, based on multi-scale models for inhomogeneous Poisson processes, to account for such variation in DNase I cleavage patterns both within and across binding sites. These models account for the spatial structure in the heterogeneity in DNase I cleavage patterns for each factor. Using DNase-seq measurements assayed in a lymphoblastoid cell line, we demonstrate the improved performance of this model for several transcription factors by comparing against the Chip-seq peaks for those factors. Finally, we explore the effects of DNase I sequence bias on inference of factor binding using a simple extension to our framework that allows for a more flexible background model. The proposed model can also be easily applied to paired-end ATAC-seq and DNase-seq data. msCentipede, a Python implementation of our algorithm, is available at http://rajanil.github.io/msCentipede.
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Affiliation(s)
- Anil Raj
- Department of Genetics, Stanford University, Stanford, California, United States of America
- * E-mail: (AR); (HS); (YG); (JKP); (MS)
| | - Heejung Shim
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- * E-mail: (AR); (HS); (YG); (JKP); (MS)
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- * E-mail: (AR); (HS); (YG); (JKP); (MS)
| | - Jonathan K. Pritchard
- Department of Genetics, Stanford University, Stanford, California, United States of America
- Department of Biology, Stanford University, Stanford, California, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail: (AR); (HS); (YG); (JKP); (MS)
| | - Matthew Stephens
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Department of Statistics, University of Chicago, Chicago, Illinois, United States of America
- * E-mail: (AR); (HS); (YG); (JKP); (MS)
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47
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Pacis A, Tailleux L, Morin AM, Lambourne J, MacIsaac JL, Yotova V, Dumaine A, Danckaert A, Luca F, Grenier JC, Hansen KD, Gicquel B, Yu M, Pai A, He C, Tung J, Pastinen T, Kobor MS, Pique-Regi R, Gilad Y, Barreiro LB. Bacterial infection remodels the DNA methylation landscape of human dendritic cells. Genome Res 2015; 25:1801-11. [PMID: 26392366 PMCID: PMC4665002 DOI: 10.1101/gr.192005.115] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 09/17/2015] [Indexed: 01/06/2023]
Abstract
DNA methylation is an epigenetic mark thought to be robust to environmental perturbations on a short time scale. Here, we challenge that view by demonstrating that the infection of human dendritic cells (DCs) with a live pathogenic bacteria is associated with rapid and active demethylation at thousands of loci, independent of cell division. We performed an integrated analysis of data on genome-wide DNA methylation, histone mark patterns, chromatin accessibility, and gene expression, before and after infection. We found that infection-induced demethylation rarely occurs at promoter regions and instead localizes to distal enhancer elements, including those that regulate the activation of key immune transcription factors. Active demethylation is associated with extensive epigenetic remodeling, including the gain of histone activation marks and increased chromatin accessibility, and is strongly predictive of changes in the expression levels of nearby genes. Collectively, our observations show that active, rapid changes in DNA methylation in enhancers play a previously unappreciated role in regulating the transcriptional response to infection, even in nonproliferating cells.
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Affiliation(s)
- Alain Pacis
- Department of Genetics, CHU Sainte-Justine Research Center, Montreal, H3T1C5 Canada; Department of Biochemistry, University of Montreal, Montreal, H3T1J4 Canada
| | - Ludovic Tailleux
- Institut Pasteur, Mycobacterial Genetics Unit, Paris, 75015 France
| | - Alexander M Morin
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, V6T1Z4, Canada
| | - John Lambourne
- Génome Québec Innovation Centre, Department of Human Genetics, McGill University, Montreal, H3A0G1 Canada
| | - Julia L MacIsaac
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, V6T1Z4, Canada
| | - Vania Yotova
- Department of Genetics, CHU Sainte-Justine Research Center, Montreal, H3T1C5 Canada
| | - Anne Dumaine
- Department of Genetics, CHU Sainte-Justine Research Center, Montreal, H3T1C5 Canada
| | | | - Francesca Luca
- Center for Molecular Medicine and Genetics and Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan 48202, USA
| | | | - Kasper D Hansen
- Department of Biostatistics and McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
| | - Brigitte Gicquel
- Institut Pasteur, Mycobacterial Genetics Unit, Paris, 75015 France
| | - Miao Yu
- Department of Chemistry and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637, USA
| | - Athma Pai
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Chuan He
- Department of Chemistry and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637, USA
| | - Jenny Tung
- Departments of Evolutionary Anthropology and Biology and Duke Population Research Institute, Duke University, Durham, North Carolina 27708, USA
| | - Tomi Pastinen
- Génome Québec Innovation Centre, Department of Human Genetics, McGill University, Montreal, H3A0G1 Canada
| | - Michael S Kobor
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, V6T1Z4, Canada
| | - Roger Pique-Regi
- Center for Molecular Medicine and Genetics and Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan 48202, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA
| | - Luis B Barreiro
- Department of Genetics, CHU Sainte-Justine Research Center, Montreal, H3T1C5 Canada; Department of Pediatrics, University of Montreal, Montreal, H3T1J4 Canada
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48
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Zhou X, Cain CE, Myrthil M, Lewellen N, Michelini K, Davenport ER, Stephens M, Pritchard JK, Gilad Y. Epigenetic modifications are associated with inter-species gene expression variation in primates. Genome Biol 2015; 15:547. [PMID: 25468404 PMCID: PMC4290387 DOI: 10.1186/s13059-014-0547-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Changes in gene regulation have long been thought to play an important role in evolution and speciation, especially in primates. Over the past decade, comparative genomic studies have revealed extensive inter-species differences in gene expression levels, yet we know much less about the extent to which regulatory mechanisms differ between species. RESULTS To begin addressing this gap, we perform a comparative epigenetic study in primate lymphoblastoid cell lines, to query the contribution of RNA polymerase II and four histone modifications, H3K4me1, H3K4me3, H3K27ac, and H3K27me3, to inter-species variation in gene expression levels. We find that inter-species differences in mark enrichment near transcription start sites are significantly more often associated with inter-species differences in the corresponding gene expression level than expected by chance alone. Interestingly, we also find that first-order interactions among the five marks, as well as chromatin states, do not markedly contribute to the degree of association between the marks and inter-species variation in gene expression levels, suggesting that the marginal effects of the five marks dominate this contribution. CONCLUSIONS Our observations suggest that epigenetic modifications are substantially associated with changes in gene expression levels among primates and may represent important molecular mechanisms in primate evolution.
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49
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Frankenberger C, Rabe D, Bainer R, Sankarasharma D, Chada K, Krausz T, Gilad Y, Becker L, Rosner MR. Metastasis Suppressors Regulate the Tumor Microenvironment by Blocking Recruitment of Prometastatic Tumor-Associated Macrophages. Cancer Res 2015; 75:4063-73. [PMID: 26238785 DOI: 10.1158/0008-5472.can-14-3394] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 06/15/2015] [Indexed: 12/20/2022]
Abstract
Triple-negative breast cancer (TNBC) patients have the highest risk of recurrence and metastasis. Because they cannot be treated with targeted therapies, and many do not respond to chemotherapy, they represent a clinically underserved group. TNBC is characterized by reduced expression of metastasis suppressors such as Raf kinase inhibitory protein (RKIP), which inhibits tumor invasiveness. Mechanisms by which metastasis suppressors alter tumor cells are well characterized; however, their ability to regulate the tumor microenvironment and the importance of such regulation to metastasis suppression are incompletely understood. Here, we use species-specific RNA sequencing to show that RKIP expression in tumors markedly reduces the number and metastatic potential of infiltrating tumor-associated macrophages (TAM). TAMs isolated from nonmetastatic RKIP(+) tumors, relative to metastatic RKIP(-) tumors, exhibit a reduced ability to drive tumor cell invasion and decreased secretion of prometastatic factors, including PRGN, and shed TNFR2. RKIP regulates TAM recruitment by blocking HMGA2, resulting in reduced expression of numerous macrophage chemotactic factors, including CCL5. CCL5 overexpression in RKIP(+) tumors restores recruitment of prometastatic TAMs and intravasation, whereas treatment with the CCL5 receptor antagonist Maraviroc reduces TAM infiltration. These results highlight the importance of RKIP as a regulator of TAM recruitment through chemokines such as CCL5. The clinical significance of these interactions is underscored by our demonstration that a signature comprised of RKIP signaling and prometastatic TAM factors strikingly separates TNBC patients based on survival outcome. Collectively, our findings identify TAMs as a previously unsuspected mechanism by which the metastasis-suppressor RKIP regulates tumor invasiveness, and further suggest that TNBC patients with decreased RKIP activity and increased TAM infiltration may respond to macrophage-based therapeutics.
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MESH Headings
- Animals
- Cell Line, Tumor/transplantation
- Chemokine CCL5/biosynthesis
- Chemokine CCL5/genetics
- Chemokine CCL5/physiology
- Chemokines/physiology
- Chemotaxis
- Cyclohexanes/pharmacology
- Cyclohexanes/therapeutic use
- Disease-Free Survival
- Female
- Gene Expression Profiling
- Gene Knockdown Techniques
- HMGA2 Protein/physiology
- Heterografts/immunology
- Humans
- Macrophages/immunology
- Mammary Neoplasms, Experimental/drug therapy
- Mammary Neoplasms, Experimental/immunology
- Maraviroc
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Nude
- Neoplasm Metastasis/immunology
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Phosphatidylethanolamine Binding Protein/physiology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Neoplasm/biosynthesis
- RNA, Neoplasm/genetics
- Receptors, CCR5/drug effects
- Sequence Analysis, RNA
- Triazoles/pharmacology
- Triazoles/therapeutic use
- Triple Negative Breast Neoplasms/immunology
- Triple Negative Breast Neoplasms/mortality
- Tumor Microenvironment/immunology
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Affiliation(s)
- Casey Frankenberger
- Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Daniel Rabe
- Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Russell Bainer
- Department of Human Genetics, University of Chicago, Chicago, Illinois
| | - Devipriya Sankarasharma
- Department of Biochemistry and Molecular Biology, Rutgers University, Piscataway, New Jersey
| | - Kiran Chada
- Department of Biochemistry and Molecular Biology, Rutgers University, Piscataway, New Jersey
| | - Thomas Krausz
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois
| | - Lev Becker
- Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois.
| | - Marsha Rich Rosner
- Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois.
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50
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Gallego Romero I, Pavlovic BJ, Hernando-Herraez I, Zhou X, Ward MC, Banovich NE, Kagan CL, Burnett JE, Huang CH, Mitrano A, Chavarria CI, Friedrich Ben-Nun I, Li Y, Sabatini K, Leonardo TR, Parast M, Marques-Bonet T, Laurent LC, Loring JF, Gilad Y. A panel of induced pluripotent stem cells from chimpanzees: a resource for comparative functional genomics. eLife 2015; 4:e07103. [PMID: 26102527 PMCID: PMC4502404 DOI: 10.7554/elife.07103] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 06/22/2015] [Indexed: 12/20/2022] Open
Abstract
Comparative genomics studies in primates are restricted due to our limited access to samples. In order to gain better insight into the genetic processes that underlie variation in complex phenotypes in primates, we must have access to faithful model systems for a wide range of cell types. To facilitate this, we generated a panel of 7 fully characterized chimpanzee induced pluripotent stem cell (iPSC) lines derived from healthy donors. To demonstrate the utility of comparative iPSC panels, we collected RNA-sequencing and DNA methylation data from the chimpanzee iPSCs and the corresponding fibroblast lines, as well as from 7 human iPSCs and their source lines, which encompass multiple populations and cell types. We observe much less within-species variation in iPSCs than in somatic cells, indicating the reprogramming process erases many inter-individual differences. The low within-species regulatory variation in iPSCs allowed us to identify many novel inter-species regulatory differences of small magnitude. DOI:http://dx.doi.org/10.7554/eLife.07103.001 Comparing the genomes of different species can reveal how they are related to one another. Such comparative studies can also reveal how genomes are modified in species-specific ways to regulate gene activity. The genomes of humans and chimpanzees are very similar in sequence. It is therefore likely that differing patterns of gene regulation underlie many of the differences observed between the two species. However, only a few kinds of chimpanzee cell that can be grown in the laboratory are available for research; this lack of samples has limited the ability of researchers to perform such comparative studies. One way around this problem is to use induced pluripotent stem cells (or iPSCs). IPSCs are created by exposing mature cells—for example, skin cells—to conditions and molecules that convert them into an embryonic-like state. This state—called ‘induced pluripotency’—allows the cells to be coaxed into becoming many different cell types that can be grown in the laboratory. But it is more difficult to establish high quality iPSCs from chimpanzees than it is from humans or mice. Gallego Romero, Pavlovic et al. have now addressed this problem by creating iPSCs from skin cells taken from seven healthy chimpanzees. These cell lines were then analysed and compared to each other and to seven iPSC lines created from human cells. The chimpanzee iPSC lines were found to be much more similar to each other than the mature cells that were used to make them. Similar results were also observed for the human iSPCs, which likely reflects the conserved changes that take place when the genomes of mature cells are reprogrammed to pluripotency. This high level of similarity between iPSCs from different individuals of the same species allowed Gallego Romero, Pavlovic et al. to discover many subtle differences in gene regulation between chimpanzees and humans. For example, over 4500 genes were found to be expressed differently in human and chimpanzee iPSCs, and over 3500 genomic regions had different patterns of certain DNA modifications that can help to regulate gene expression. These newly created chimpanzee iPSC lines represent a valuable resource for comparative studies of gene regulation. In the future, this resource could help researchers to identify further differences in gene regulation between closely related primate species. DOI:http://dx.doi.org/10.7554/eLife.07103.002
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Affiliation(s)
| | - Bryan J Pavlovic
- Department of Human Genetics, University of Chicago, Chicago, United States
| | | | - Xiang Zhou
- Department of Biostatistics, University of Michigan, Ann Arbor, United States
| | - Michelle C Ward
- Department of Human Genetics, University of Chicago, Chicago, United States
| | | | - Courtney L Kagan
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Jonathan E Burnett
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Constance H Huang
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Amy Mitrano
- Department of Human Genetics, University of Chicago, Chicago, United States
| | | | - Inbar Friedrich Ben-Nun
- Center for Regenerative Medicine, Department of Chemical Physiology, The Scripps Research Institute, La Jolla, United States
| | - Yingchun Li
- Department of Pathology, University of California San Diego, San Diego, United States
| | - Karen Sabatini
- Center for Regenerative Medicine, Department of Chemical Physiology, The Scripps Research Institute, La Jolla, United States
| | - Trevor R Leonardo
- Center for Regenerative Medicine, Department of Chemical Physiology, The Scripps Research Institute, La Jolla, United States
| | - Mana Parast
- Department of Pathology, University of California San Diego, San Diego, United States
| | | | - Louise C Laurent
- Sanford Consortium for Regenerative Medicine, La Jolla, United States
| | - Jeanne F Loring
- Center for Regenerative Medicine, Department of Chemical Physiology, The Scripps Research Institute, La Jolla, United States
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, United States
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