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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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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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Kim HD, Turner JT, Burnett JE, Joo NS, Han BH, Lim RW, Bowen JW, Kirk RG, Lee P. Furosemide stimulates K transport in HCD57 erythroid cells. J Membr Biol 2000; 175:235-44. [PMID: 10833533 DOI: 10.1007/s00232001071] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Indexed: 11/29/2022]
Abstract
We examined the influence of serum and furosemide on K movement and cell volume in HCD57 cells, a murine erythroleukemia cell line, which require erythropoietin (EPO) for survival. We found that maintenance of cell volume depends on the concentration of serum in the culture medium. In isotonic medium containing 20% serum, HCD57 cells maintain their steady-state volume. In contrast, the cells shrink progressively as medium serum content is reduced. In serum-free medium, raising external K to 75 mm prevents cell shrinkage and a further increase in K to 145 mm results in swelling, revealing a role for K permeability in the regulation of cell volume. Of particular interest has been a serendipitous finding with furosemide. Below an external K concentration of 2.1 +/- 0.3 mm in medium containing 2% serum, furosemide inhibits K uptake, probably stemming from its well known inhibitory action on KCl cotransport. However, above that K concentration, furosemide stimulates K uptake in a dose-dependent manner. Moreover, furosemide potentiates cell shrinkage induced by serum withdrawal. These findings suggest that the transport machinery mediating cellular shrinkage, once primed by serum depletion, becomes receptive to a second stimulus.
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Affiliation(s)
- H D Kim
- Department of Pharmacology, University of Missouri, M517B Medical Sciences Building, One Hospital Center Dr., Columbia, MO 65212, USA
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Kim HD, Bowen JW, James-Kracke MR, Landon LA, Camden JM, Burnett JE, Turner JT. Potentiation of regulatory volume decrease by P2U purinoceptors in HSG-PA cells. Am J Physiol 1996; 270:C86-97. [PMID: 8772433 DOI: 10.1152/ajpcell.1996.270.1.c86] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
HSG-PA human salivary gland duct cells exhibit progressively increased regulatory volume decrease (RVD) in response to decreased medium osmolarity. The P2U purinoceptor agonist UTP causes a potentiation of RVD, the extent of which is most pronounced in 220 mosM medium and is least apparent in 180 mosM medium. We examined the underlying mechanisms for this effect. Exposure of HSG-PA cells to UTP promotes Ca2+ mobilization, hyperpolarization, and net K+ efflux, suggesting the participation of Ca(2+)-activated K+ channels in RVD. To delineate the anion counterpart of K+ movement during RVD, cell swelling in the presence of gramicidin, which abolishes the membrane potential, was measured. In response to a sudden dilution in hypotonic media, gramicidin-treated cells swelled immediately, followed by a "secondary swelling" in 180 but not in 220 mosM medium. The results suggest that in 180 mosM cells perform spontaneous RVD mediated by increased anion conductance. In 220 mosM medium in which RVD is minimal, the increase in anion conductance is marginal. In our model of RVD in which cells were challenged by UTP, the ensuing hyperpolarization provides the driving force for net Cl- efflux, which is confirmed by tracer flux studies during purinoceptor-activated RVD. Thus RVD, which has long been regarded as a self-sufficient cellular program, appears to be subject to extracellular control in HSG-PA cells through receptor-mediated processes.
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Affiliation(s)
- H D Kim
- Department of Pharmacology, School of Medicine, University of Missouri, Columbia 65212, USA
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Abstract
Two complimentary assay techniques were used to determine triazolam levels in greyhound urine samples following a single oral dose. The results from the trials were statistically compared. The relative non-specificity of the benzodiazepine antibody used in radioimmunoassay caused a significant difference in teh two sets of results. This was independent of hydrolysis.
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Affiliation(s)
- J E Burnett
- Department of Forensic Medicine and Science, University of Glasgow, U.K
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Emmons L, Burnett JE, Finkelstein R, Frieder B, Long G, Lettenauer D, Miller C. Millions of medical care dollars for indigents. J Community Health 1983; 9:30-48. [PMID: 6689583 DOI: 10.1007/bf01318932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The medically indigent, a group traditionally underserved with health care, can obtain some needed free services from Hill-Burton facilities. These facilities (hospitals, nursing homes, clinics, and agencies) received Hill-Burton funds for their building programs and have, as a result, an obligation to provide a certain amount of uncompensated medical care to a defined medically indigent population. Health systems agencies (HSAS) or other interested agencies and groups can play an integral role in highlighting the Hill-Burton Program and helping the medically indigent obtain free care, This paper describes the Hill-Burton Program and explains how one HSA identified the Hill-Burton facilities in its area, determined the extent of their obligations, obtained allocation plans, and publicized and promoted the available health care services. From the interest shown by the community it was apparent that the HSA had provided a much needed and appreciated service that could be duplicated across the country by HSAS or other community groups.
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Baehr EF, McGannon WJ, Burnett JE, Felder SF, Shin DH. Intraocular pressure reduction and regulation system. Int Ophthalmol Clin 1981; 21:183-98. [PMID: 7216643 DOI: 10.1097/00004397-198102110-00018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The IOP reduction and regulation system performs certain specific functions: it can be used to lower (or raise) IOP in a controlled way; it responds rapidly to maintain a selectable, set, minimum IOP under variable flow demands; and it reduces the rapid dynamic increases in IOP resulting from loads applied to the eye. The system has been tested and evaluated in the laboratory with a small test chamber and excised animal eyes and subsequently with anesthetized live animals. The system has also had limited clinical use in selected patients. An expanded program of laboratory and clinical investigations is planned.
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Burnett JE. A physician-sponsored community nurse-midwife program. Obstet Gynecol 1972; 40:719-23. [PMID: 5083224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Burnett JE. Preinduction scoring: an objective approach to induction of labor. Obstet Gynecol 1966; 28:479-83. [PMID: 5925032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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