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Epigenetics

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Articles 1 - 24 of 24

Full-Text Articles in Cell Biology

The Genome-Wide Multi-Layered Architecture Of Chromosome Pairing In Early Drosophila Embryos, Jelena Erceg, Jumana Alhaj Abed, Anton Goloborodko, Bryan R. Lajoie, Geoffrey Fudenberg, Nezar Abdennur, Maxim Imakaev, Ruth B. Mccole, Son C. Nguyen, Wren Saylor, Eric F. Joyce, T. Niroshini Senaratne, Mohammed A. Hannan, Guy Nir, Job Dekker, Leonid A. Mirny, C-Ting Wu Oct 2019

The Genome-Wide Multi-Layered Architecture Of Chromosome Pairing In Early Drosophila Embryos, Jelena Erceg, Jumana Alhaj Abed, Anton Goloborodko, Bryan R. Lajoie, Geoffrey Fudenberg, Nezar Abdennur, Maxim Imakaev, Ruth B. Mccole, Son C. Nguyen, Wren Saylor, Eric F. Joyce, T. Niroshini Senaratne, Mohammed A. Hannan, Guy Nir, Job Dekker, Leonid A. Mirny, C-Ting Wu

Program in Systems Biology Publications and Presentations

Genome organization involves cis and trans chromosomal interactions, both implicated in gene regulation, development, and disease. Here, we focus on trans interactions in Drosophila, where homologous chromosomes are paired in somatic cells from embryogenesis through adulthood. We first address long-standing questions regarding the structure of embryonic homolog pairing and, to this end, develop a haplotype-resolved Hi-C approach to minimize homolog misassignment and thus robustly distinguish trans-homolog from cis contacts. This computational approach, which we call Ohm, reveals pairing to be surprisingly structured genome-wide, with trans-homolog domains, compartments, and interaction peaks, many coinciding with analogous cis features. We also find a ...


Histone Citrullination Represses Mirna Expression Resulting In Increased Oncogene Mrnas In Somatolactotrope Cells., Stanley B Devore, Coleman H. Young, Guangyuan Li, Anitha Sundararajan, Thiruvarangan Ramaraj, Joann Mudge, Faye Schilkey, Aaron Muth, Paul R. Thompson, Brian D. Cherrington Sep 2018

Histone Citrullination Represses Mirna Expression Resulting In Increased Oncogene Mrnas In Somatolactotrope Cells., Stanley B Devore, Coleman H. Young, Guangyuan Li, Anitha Sundararajan, Thiruvarangan Ramaraj, Joann Mudge, Faye Schilkey, Aaron Muth, Paul R. Thompson, Brian D. Cherrington

University of Massachusetts Medical School Publications

Peptidylarginine deiminase (PAD) enzymes convert histone arginine residues into citrulline to modulate chromatin organization and gene expression. Although PADs are expressed in anterior pituitary gland cells, their functional role and expression in pituitary adenomas is unknown. To begin to address these questions, we first examined normal human pituitaries and pituitary adenomas and found that PAD2, PAD4 and citrullinated histones are highest in prolactinomas and somatoprolactinomas. In the somatoprolactinoma-derived GH3 cell line, PADs citrullinate histone H3, which is attenuated by a pan-PAD inhibitor. RNA-sequencing and ChIP studies show that the expression of microRNAs let-7c-2, miR-23b and miR-29c is suppressed by histone ...


Identification Of Epigenetic Regulators Of Dux4-Fl For Targeted Therapy Of Facioscapulohumeral Muscular Dystrophy, Charis L. Himeda, Takako I. Jones, Ching-Man A. Virbasius, Lihua Julie Zhu, Michael R. Green, Peter L. Jones Apr 2018

Identification Of Epigenetic Regulators Of Dux4-Fl For Targeted Therapy Of Facioscapulohumeral Muscular Dystrophy, Charis L. Himeda, Takako I. Jones, Ching-Man A. Virbasius, Lihua Julie Zhu, Michael R. Green, Peter L. Jones

Open Access Articles

Facioscapulohumeral muscular dystrophy (FSHD) is caused by epigenetic de-repression of the disease locus, leading to pathogenic misexpression of the DUX4 gene in skeletal muscle. While the factors and pathways involved in normal repression of the FSHD locus in healthy cells have been well characterized, very little is known about those responsible for the aberrant activation of DUX4-fl in FSHD myocytes. Reasoning that DUX4-fl activators might represent useful targets for small molecule inhibition, we performed a highly targeted, candidate-based screen of epigenetic regulators in primary FSHD myocytes. We confirmed several of the strongest and most specific candidates (ASH1L, BRD2, KDM4C, and ...


Investigation Of Alcohol-Induced Changes In Hepatic Histone Modifications Using Mass Spectrometry Based Proteomics, Crystina Leah Kriss Apr 2018

Investigation Of Alcohol-Induced Changes In Hepatic Histone Modifications Using Mass Spectrometry Based Proteomics, Crystina Leah Kriss

Graduate Theses and Dissertations

Alcohol liver disease (ALD) is a major health concern throughout the world. Currently, in the United States, 17 million people suffer from alcoholism, of which 1.4 million people are receiving treatment [1, 2]. The link between ethanol metabolism, reactive oxygen species (ROS) and liver injury in ALD has been well characterized over the last couple decades [3-10]. Ethanol metabolism relies on the availability of the cofactor NAD+ for the oxidation of ethanol into acetate, consequently causing alterations in redox potential. Redox dysfunction within the mitochondria can affect multiple pathways important in maintaining cellular homeostasis. Chapter 1 provides an introduction ...


Ki-67 Regulates Cell Cycle Progression And Heterochromatin Organization, Xiaoming Sun Sep 2017

Ki-67 Regulates Cell Cycle Progression And Heterochromatin Organization, Xiaoming Sun

GSBS Dissertations and Theses

A subset of eukaryotic heterochromatin is located around the nucleoli, and this localization is correlated with gene silencing. Although there is some evidence for trans-acting factors organizing genomic loci around the nucleolus, the characterization of proteins and /or RNAs involved in perinculeolar heterochromatin localization and maintenance is incomplete. Notably, the mammalian female inactive X chromosome, a well-studied model of facultative heterochromatin, frequently resides in the perinucleolar regions during mid to late S phase. The disruption of the Xi–nucleolus association results in the erosion of heterochromatin compartment and silencing, which renders it a good model to investigate the mechanism and ...


Intergenerational Effects Of Nicotine In An Animal Model Of Paternal Nicotine Exposure, Markus Parzival Vallaster Aug 2017

Intergenerational Effects Of Nicotine In An Animal Model Of Paternal Nicotine Exposure, Markus Parzival Vallaster

GSBS Dissertations and Theses

Environmental conditions imposed onto organisms during certain phases of their life cycles such as embryogenesis or puberty can not only impact the organisms’ own health, but also affect subsequent generations. The underlying mechanisms causing intergenerational phenotypes are not encoded in the genome, but the result of reversible epigenetic modifications. This work investigates in a mouse model the impact of paternal nicotine exposure on the next generation regarding addictive behavior modulation, metabolic changes, and molecular mechanisms. It provides evidence that male offspring from nicotine-exposed fathers (NIC offspring) is more resistant to lethal doses of nicotine. This phenotype is gender-specific and depends ...


The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers Aug 2017

The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers

Electronic Theses and Dissertations

Primordial germ cells (PGCs) are hypothesized to deposit hematopoietic stem cells (HSCs) along their migration route through the embryo during the early stages of embryogenesis. PGCs also undergo global chromatin remodeling, including the erasure and reestablishment of genomic imprints, during this migration. While PGCs do not spontaneously form teratomas, their malignant development into germ cell tumors (GCTs) in vivo is often accompanied by the retention of hypomethylation at the IGF2-H19 imprinting control differentially methylated region (DMR). Previous studies in bimaternal embryos determined that proper genomic imprinting at two paternally imprinted loci was necessary for their growth and development: Igf2-H19 and ...


Histone Variant Macroh2a In The Gut And Beyond: A Study Of Intestinal Fortitude, Ryan James Cedeno Jan 2017

Histone Variant Macroh2a In The Gut And Beyond: A Study Of Intestinal Fortitude, Ryan James Cedeno

Publicly Accessible Penn Dissertations

Epigenetic factors guide chromatin remodeling during cell state transitions and confer resistance to genotoxic stressors that could induce deleterious transformations. A particularly peculiar component of the epigenome with emerging roles in fine-tuning cell identity and upholding genomic stability is the structural histone variant macroH2A. Relatively little is currently known about macroH2A’s influence on overall cell developmental potency and less still is known about macroH2A’s contributions to adult stem cell identity and function in vivo. In this work, we use induced pluripotent stem cell (iPSC) reprogramming and the murine intestinal stem cell (ISC) system to model macroH2A’s overall ...


Histone Deacetylase 3 Coordinates Heart Development Through Stage-Specific Roles In Cardiac Progenitor Cells, Sara L. Lewandowski Dec 2016

Histone Deacetylase 3 Coordinates Heart Development Through Stage-Specific Roles In Cardiac Progenitor Cells, Sara L. Lewandowski

GSBS Dissertations and Theses

Disruptions in cardiac development cause congenital heart disease, the most prevalent and deadly congenital malformation. Genetic and environmental factors are thought to contribute to these defects, however molecular mechanisms remain largely undefined. Recent work highlighted potential roles of chromatin- modifying enzymes in congenital heart disease pathogenesis. Histone deacetylases, a class of chromatin-modifying enzymes, have developmental importance and recognized roles in the mature heart. This thesis aimed to characterize functions of Hdac3 in cardiac development. We found loss of Hdac3 in the primary heart field causes precocious progenitor cell differentiation, resulting in hypoplastic ventricular walls, ventricular septal defect, and mid- gestational ...


Microenvironment-Induced Pten Loss By Exosomal Microrna Primes Brain Metastasis Outgrowth, Lin Zhang Dec 2016

Microenvironment-Induced Pten Loss By Exosomal Microrna Primes Brain Metastasis Outgrowth, Lin Zhang

UT GSBS Dissertations and Theses (Open Access)

Development of life-threatening cancer metastases at distant organs requires disseminated tumor cells’ adaptation to and co-evolution with the drastically different microenvironments of metastatic sites. Cancer cells of common origin manifest distinct gene expression patterns after metastasizing to different organs. Clearly, the dynamic interplay between metastatic tumor cells and extrinsic signals at individual metastatic organ sites critically impacts the subsequent metastatic outgrowth. Yet, it is unclear when and how disseminated tumor cells acquire the essential traits from the microenvironment of metastatic organs that prime their subsequent outgrowth. Here we show that primary tumor cells with normal expression of PTEN, an important ...


Nucleoporin-Mediated Regulation Of The Kcnq1ot1 Imprinted Domain, Saqib Sachani Aug 2016

Nucleoporin-Mediated Regulation Of The Kcnq1ot1 Imprinted Domain, Saqib Sachani

Electronic Thesis and Dissertation Repository

Genomic imprinting is an epigenetic phenomenon that restricts gene expression to one parental allele while the other copy is silent. How this duality is regulated is not fully understood. Using the Kcnq1ot1 imprinted domain as a model, previous work in the laboratory identified nucleoporin 107 as a candidate regulator of imprinted domain regulation. Within the Kcnq1ot1 domain resides the imprinting control region, the paternally expressed Kcnq1ot1 (Kcnq1 opposite transcript 1) noncoding RNA, nine maternal-expressed protein-coding genes, as well as genes that escape imprint regulation. On the maternal allele, the Kcnq1ot1 imprinting control region is methylated, silencing the embedded Kcnq1ot1 promoter ...


Targeting The Chromatin Remodeling Enzyme Brg1 Increases The Efficacy Of Chemotherapy Drugs In Breast Cancer Cells, Qiong Wu, Soni Sharma, Hang Cui, Scott E. Leblanc, Hong Zhang, Rohini Muthuswami, Jeffrey A. Nickerson, Anthony N. Imbalzano Mar 2016

Targeting The Chromatin Remodeling Enzyme Brg1 Increases The Efficacy Of Chemotherapy Drugs In Breast Cancer Cells, Qiong Wu, Soni Sharma, Hang Cui, Scott E. Leblanc, Hong Zhang, Rohini Muthuswami, Jeffrey A. Nickerson, Anthony N. Imbalzano

Cell and Developmental Biology Publications

Brahma related gene product 1 (BRG1) is an ATPase that drives the catalytic activity of a subset of the mammalian SWI/SNF chromatin remodeling enzymes. BRG1 is overexpressed in most human breast cancer tumors without evidence of mutation and is required for breast cancer cell proliferation. We demonstrate that knockdown of BRG1 sensitized triple negative breast cancer cells to chemotherapeutic drugs used to treat breast cancer. An inhibitor of the BRG1 bromodomain had no effect on breast cancer cell viability, but an inhibitory molecule that targets the BRG1 ATPase activity recapitulated the increased drug efficacy observed in the presence of ...


Epigenetic Regulation Of The Dlk1-Meg3 Imprinted Locus In Human Islets, Vasumathi Kameswaran Jan 2016

Epigenetic Regulation Of The Dlk1-Meg3 Imprinted Locus In Human Islets, Vasumathi Kameswaran

Publicly Accessible Penn Dissertations

Type 2 diabetes mellitus (T2DM) is a complex metabolic disease characterized by inadequate insulin secretion by the pancreatic β-cell in response to increased blood glucose levels. Despite compelling evidence that T2DM has a high rate of familial aggregation, known genetic risk variants account for less than 10% of the observed heritability. Consequently, post-transcriptional regulators of gene expression, including microRNAs and other noncoding RNAs, have been implicated in the etiology of T2DM, in part due to their ability to simultaneously regulate the expression of hundreds of targets.

To determine if microRNAs are involved in the pathogenesis of human T2DM, I sequenced ...


The Mitotic Genome: Accessibility And Transcriptional Control, Chris Hsiung Jan 2016

The Mitotic Genome: Accessibility And Transcriptional Control, Chris Hsiung

Publicly Accessible Penn Dissertations

Mitosis entails dramatic global alterations to genome structure and regulation, including

chromosome condensation, dissociation of the transcriptional machinery from chromosomes, and transcriptional silencing. Here I report studies that address the macromolecular accessibility of the mitotic genome and the control of transcriptional reactivation upon mitotic exit in a mammalian cell line. The results obtained from measuring the sensitivity of chromatin to DNase I cleavage by sequencing (DNase-seq) in pure mitotic cell populations demonstrate that macromolecular accessibility of the mitotic genome is widely preserved. Thus, steric hindrance from chromatin condensation is insufficient for explaining the eviction of transcription factors from mitotic chromatin ...


Interplay Between P53 And Epigenetic Pathways In Cancer, Jiajun Zhu Jan 2016

Interplay Between P53 And Epigenetic Pathways In Cancer, Jiajun Zhu

Publicly Accessible Penn Dissertations

The human TP53 gene encodes the most potent tumor suppressor protein p53. More than half of all human cancers contain mutations in the TP53 gene, while the majority of the remaining cases involve other mechanisms to inactivate wild-type p53 function. In the first part of my dissertation research, I have explored the mechanism of suppressed wild-type p53 activity in teratocarcinoma. In the teratocarcinoma cell line NTera2, we show that wild-type p53 is mono-methylated at Lysine 370 and Lysine 382. These post-translational modifications contribute to the compromised tumor suppressive activity of p53 despite a high level of wild-type protein in NTera2 ...


Acute Methamphetamine Exposure Affects Histone Modifying Enzymes And Cytokine Production In Macrophages, Ariel Burns Dec 2015

Acute Methamphetamine Exposure Affects Histone Modifying Enzymes And Cytokine Production In Macrophages, Ariel Burns

Theses & Dissertations

The effects of methamphetamine (Meth) in the periphery are not well studied and a comprehensive investigation on the effects and molecular mechanism will give insight into why Meth users are at an increased risk of infections. For this reason, we use macrophages as a model for the immune system dysregulation seen in Meth abusers and also because macrophages are a long-lived cell that HIV infects and persists in. We aimed to determine the effects of Meth on the cytokine production, histone modifying enzymes and the corresponding histone post-translational modifications, and the molecular mechanism in HIV-infected human macrophages treated with combination ...


Targeting Stress Response Pathways In Soft Tissue Sarcoma: The Role Of Hypoxia And Autophagy In Tumor Survival, Michael Nakazawa Jan 2015

Targeting Stress Response Pathways In Soft Tissue Sarcoma: The Role Of Hypoxia And Autophagy In Tumor Survival, Michael Nakazawa

Publicly Accessible Penn Dissertations

Soft tissue sarcomas (STS) are a group of malignancies that arise from mesenchymal tissue, consisting of over 50 distinct histiologic subtypes. Unfortunately, the five-year survival rate of sarcoma patients has remained relatively unchanged, and due to the rarity of the disease, research and development of adequate therapeutics for STS lags behind other cancers. Therefore, understanding the molecular drivers of STS is important in developing new therapeutics, as well as discovering druggable processes that occur across multiple subtypes. One feature common to STS is hypoxia, or low O2 conditions. Using molecular biology, biochemical approaches, genetically engineered mouse models, as well as ...


Understanding Ten-Eleven Translocation-2 In Hematological And Nervous Systems, Feng Pan Dec 2014

Understanding Ten-Eleven Translocation-2 In Hematological And Nervous Systems, Feng Pan

FIU Electronic Theses and Dissertations

I proposed the study of two distinct aspects of Ten-Eleven Translocation 2 (TET2) protein for understanding specific functions in different body systems.

In Part I, I characterized the molecular mechanisms of Tet2 in the hematological system. As the second member of Ten-Eleven Translocation protein family, TET2 is frequently mutated in leukemic patients. Previous studies have shown that the TET2 mutations frequently occur in 20% myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN), 10% T-cell lymphoma leukemia and 2% B-cell lymphoma leukemia. Genetic mouse models also display distinct phenotypes of various types of hematological malignancies. I performed 5-hydroxymethylcytosine (5hmC) chromatin immunoprecipitation sequencing (ChIP-Seq ...


Transcription Factor Binding To Caenorhabditis Elegans First Introns Reveals Lack Of Redundancy With Gene Promoters, Juan I. Fuxman Bass, Alex M. Tamburino, Akihiro Mori, Nathan Beittel, Matthew T. Weirauch, John S. Reece-Hoyes, Albertha J. M. Walhout Jan 2014

Transcription Factor Binding To Caenorhabditis Elegans First Introns Reveals Lack Of Redundancy With Gene Promoters, Juan I. Fuxman Bass, Alex M. Tamburino, Akihiro Mori, Nathan Beittel, Matthew T. Weirauch, John S. Reece-Hoyes, Albertha J. M. Walhout

Program in Systems Biology Publications and Presentations

Gene expression is controlled through the binding of transcription factors (TFs) to regulatory genomic regions. First introns are longer than other introns in multiple eukaryotic species and are under selective constraint. Here we explore the importance of first introns in TF binding in the nematode Caenorhabditis elegans by combining computational predictions and experimentally derived TF-DNA interaction data. We found that first introns of C. elegans genes, particularly those for families enriched in long first introns, are more conserved in length, have more conserved predicted TF interactions and are bound by more TFs than other introns. We detected a significant positive ...


Hdac3 Is A Critical Regulator Of Neural Crest Progenitor Cell Biology, Nikhil Singh Jan 2012

Hdac3 Is A Critical Regulator Of Neural Crest Progenitor Cell Biology, Nikhil Singh

Publicly Accessible Penn Dissertations

Vertebrate embryogenesis relies on the coordinated development of multiple progenitor cell pools. Specific transcriptional programs regulate the specification, expansion, migration and eventual differentiation of these progenitor cell populations, and tight control of these programs is essential for normal development to occur. Class I histone deacetylases (Hdacs), including Hdac3, play critical roles in regulating gene transcription, through both epigenetic and non-epigenetic means. In this dissertation, I use mouse genetics to explore the previously undescribed role of Hdac3 in regulating neural crest progenitor cell behavior. By genetically deleting Hdac3 in premigratory neural crest cells, I use in vivo and ex vivo techniques ...


The Central Role Of Menin And Wild-Type Mll In Mll-Af9-Induced Leukemia, Austin Thiel Jan 2012

The Central Role Of Menin And Wild-Type Mll In Mll-Af9-Induced Leukemia, Austin Thiel

Publicly Accessible Penn Dissertations

Chromosomal translocations involving the Mixed Lineage Leukemia (MLL) gene lead to the expression of MLL fusion proteins and acute leukemia. MLL fusion protein-induced leukemia is aggressive, and often refractory to therapy, highlighting the importance of studying the pathogenesis of this disease. MLL fusion proteins upregulate wild-type MLL target genes, including HOX genes, and block hematopoietic differentiation, promoting leukemogenesis. However, the precise mechanism by which MLL fusion proteins upregulate HOX genes and block differentiation has been unclear. My thesis

research shows that leukemia cells expressing the MLL fusion protein MLL-AF9 also express wild-type MLL from the non-translocated MLL allele. Wild-type MLL ...


Definition Of The Landscape Of Chromatin Structure At The Frataxin Gene In Friedreich’S Ataxia, Eunah Kim Dec 2011

Definition Of The Landscape Of Chromatin Structure At The Frataxin Gene In Friedreich’S Ataxia, Eunah Kim

UT GSBS Dissertations and Theses (Open Access)

Friedreich’s ataxia (FRDA) is caused by the transcriptional silencing of the frataxin (FXN) gene. FRDA patients have expansion of GAA repeats in intron 1 of the FXN gene in both alleles. A number of studies demonstrated that specific histone deacetylase inhibitors (HDACi) affect either histone modifications at the FXN gene or FXN expression in FRDA cells, indicating that the hyperexpanded GAA repeat may facilitate heterochromatin formation. However, the correlation between chromatin structure and transcription at the FXN gene is currently limited due to a lack of more detailed analysis. Therefore, I analyzed the effects of the hyperexpanded GAA repeats ...


Mechanism Of Transcriptional Suppression Of A Phytochrome A Epiallele In Arabidopsis Thaliana, Gulab D. Rangani Aug 2011

Mechanism Of Transcriptional Suppression Of A Phytochrome A Epiallele In Arabidopsis Thaliana, Gulab D. Rangani

Theses and Dissertations

Cytosine methylation in DNA is an integral part of epigenetically controlled regulatory networks in eukaryotes. Both plants and vertebrates display DNA methylation in the gene coding region; however, its role in gene expression is not well understood. Gene promoter, on the other hand, remains largely unmethylated. Acquisition of methylation in promoter results in transcriptional suppression of the gene. The goal of this research is to study the effect of coding region methylation in gene expression using a unique gene model, phyA'. phyA' is a transcriptionally suppressed epiallele of the Arabidopsis thaliana Phytochrome A gene, which contains methylation in CG sites ...


Macroh2a1 Regulation During The Cell Cycle Of Mouse Embryonic Stem Cells, Persis S. Thomas May 2010

Macroh2a1 Regulation During The Cell Cycle Of Mouse Embryonic Stem Cells, Persis S. Thomas

Honors Scholar Theses

MacroH2A is a core histone variant that plays an important role in the X-inactivation process during differentiation of embryonic stem cells. It has been shown that macroH2A changes in localization during the cell cycle of somatic cells. This study aims to determine how macroH2A changes during the cell cycle of embryonic stem cells. Male and female mouse embryonic stem cells were transfected with a GFP::macroH2A construct and the relationship between macroH2A and the cell cycle was determined using FACS. This study shows that macroH2A is altered during the cell cycle of embryonic stem cells as it is in somatic ...