Biochemistry, Biophysics, and Structural Biology Commons^™

Divergent Transcriptional Regulation Of Suppressors Of Cytokine Signaling Genes In Adipocytes, Paula Mota De Sa

LSU Doctoral Dissertations

The Janus Kinase - Signal Transducer and Activator of Transcription (JAK-STAT) signaling pathway transduces several signals crucial for development and homeostasis. Suppressors of cytokine signaling (SOCS) proteins control JAK-STAT signaling via a negative feedback loop. The transcription factor STAT5 is known to play a significant role in fat cell development and function, and several studies suggest that acetylation may affect STAT5 transcriptional activity. To test this hypothesis, we treated 3T3-L1 adipocytes with growth hormone (GH) to activate STAT5 in the presence or absence of histone deacetylase (HDAC) inhibitors. STAT5 acetylation levels were low in adipocytes and mostly unchanged by the …

Advanced Proteomic And Epigenetic Characterization Of Ethanol-Induced Microglial Activation, Jennifer Guergues Guergues

USF Tampa Graduate Theses and Dissertations

Microglia, the resident immune cells of the brain, can exhibit a broad range of activation phenotypes and have been implicated in several diseases and disorders of the central nervous system. Here, we described a method optimized for sensitive and rapid quantitative proteomic analysis of microglia that involves suspension trapping (S-Trap) for efficient and reproducible protein extraction from a microglial cell count expected from an individual mouse brain (~300K) while also simultaneously providing the first comprehensive proteomic characterization of a novel adult-derived mouse microglial cell line. This enhanced method was used throughout all subsequent works and was especially necessary when we …

Investigating The Role Of The Chromosome 19 Microrna Cluster In Human Trophoblast Differentiation And Infantile Hemangioma, Ezinne Francess Mong

USF Tampa Graduate Theses and Dissertations

Trophoblast differentiation and invasion is essential for normal implantation and establishment of the maternal-fetal interface, which allows for proper nutrient exchange and support of the fetus. For this to occur, cytotrophoblasts must undergo an epithelial to mesenchymal transition and differentiate into migratory and invasive extravillous trophoblasts (EVTs) that invade the maternal decidua and myometrium. Trophoblast differentiation, migration and invasion is highly regulated by a complex network of signaling pathways, adhesion molecules and transcription factors and is important for the remodeling of maternal spiral arteries from low flow, high resistance to high flow, low resistance vessels to allow optimal perfusion of …

Parp1 Is A Versatile Factor In The Regulation Of Mrna Stability And Decay, Elena A. Matveeva, Lein F. Mathbout, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

PARP1 is an abundant nuclear protein with many pleiotropic functions involved in epigenetic and transcriptional controls. Abundance of mRNA depends on the balance between synthesis and decay of a particular transcript. PARP1 binds RNA and its depletion results in increased expression of genes involved in nonsense-mediated decay, suggesting that PARP1 might be involved in mRNA stability. This is of interest considering RNA binding proteins play key roles in post-transcriptional processes in all eukaryotes. We tested the direct impact of PARP1 and PARylation on mRNA stability and decay. By measuring the half-lives of two PARP1-mRNA targets we found that the half-lives …

Coupling Of Parp1-Mediated Chromatin Structural Changes To Transcriptional Rna Polymerase Ii Elongation And Cotranscriptional Splicing, Elena A. Matveeva, Qamar M. H. Al-Tinawi, Eric C. Rouchka, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Background: Recently, we showed that PARP1 is involved in cotranscriptional splicing, possibly by bridging chromatin to RNA and recruiting splicing factors. It also can influence alternative splicing decisions through the regulation of RNAPII elongation. In this study, we investigated the effect of PARP1-mediated chromatin changes on RNAPII movement, during transcription and alternative splicing.

Results: We show that RNAPII pauses at PARP1–chromatin structures within the gene body. Knockdown of PARP1 abolishes this RNAPII pausing, suggesting that PARP1 may regulate RNAPII elongation. Additionally, PARP1 alters nucleosome deposition and histone post-translational modifications at specific exon–intron boundaries, thereby affecting RNAPII movement. Lastly, genome-wide analyses …

Bisthioether Stapled Peptides Targeting Polycomb Repressive Complex 2 Gene Repression, Gan Zhang

Dissertations, Theses, and Capstone Projects

Interactions between proteins play a key role in nearly all cellular process, and therefore, disruption of such interactions may lead to many different types of cellular dysfunctions. Hence, pathologic protein-protein interactions (PPIs) constitute highly attractive drug targets and hold great potential for developing novel therapeutic agents for the treatment of incurable human diseases. Unfortunately, the identification of PPI inhibitors is an extremely challenging task, since traditionally used small molecule ligands are mostly unable to cover and anchor on the extensive flat surfaces that define those binary protein complexes. In contrast, large biomolecules such as proteins or peptides are ideal fits …

Genetic And Epigenetic Investigations On Pulmonary Hypertension Syndrome In Meat Type- Chickens, Khaloud Alzahrani

Graduate Theses and Dissertations

This dissertation presents a collection of studies that investigate the genetic and epigenetic associations to ascites phenotype in broiler chickens. Ascites is a significant metabolic disease associated with fast-growing meat-type chickens (broilers) and is a terminal result of pulmonary hypertension syndrome PHS. It is a multi-factorial syndrome caused by interactions between genetic, physiological, environmental, and managemental factors. It was estimated that ascites accounts for losses of about US$1 billion annually worldwide and for over 25% of broilers mortality. Although traditional and molecular genetic methods in the selection and in performance improvements, has greatly reduced ascites frequency, yet it has not …

Role Of P300 Zz Domain In Chromatin Association And Histone Acetylation, Yongming Xue

Dissertations and Theses (Open Access)

Transcription is strictly regulated by numerous factors including transcription coactivators. The p300 protein and its close paralogue CREB-binding protein (CREBBP, aka CBP) are well-known transcriptional coactivators that have intrinsic lysine acetyltransferase activity. The functions of p300/CBP largely rely on their capabilities to bind to chromatin and to acetylate the histone substrates. However, the molecular mechanisms underlying the regulation of these processes are not fully understood.

Through combination of various biochemical, biophysical and molecular approaches, we show that the ZZ-type zinc finger (ZZ) domain of p300 functions as a histone reader that specifically binds the N-terminal tail of histone H3. Crystal …

The Regulation Of Dna Methylation In Mammalian Development And Cancer, Nicolas Veland

Dissertations and Theses (Open Access)

DNA methylation is an essential epigenetic modification in mammals, as it plays important regulatory roles in multiple biological processes, such as gene transcription, maintenance of chromosomal structure and genomic stability, genomic imprinting, retrotransposon silencing, and X-chromosome inactivation. Dysregulation of DNA methylation is associated with various human diseases. For example, cancer cells usually show global hypomethylation and regional hypermenthylation, which have been implicated in genomic instability and tumor suppressor silencing, respectively. Although great progress has been made in elucidating the biological functions of DNA methylation over the last several decades, how DNA methylation patterns and levels are regulated and dysregulated is …

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

USF Tampa 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 to …

Selective Inhibition Of Ctcf Binding By Ias Directs Tet-Mediated Reprogramming Of 5-Hydroxymethylation Patterns In Ias-Transformed Cells, Matthew Rea, Tyler Gripshover, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Methylation at cytosine (5mC) is a fundamental epigenetic DNA modification recently associated with iAs-mediated carcinogenesis. In contrast, the role of 5-hydroxymethylcytosine (5hmC), the oxidation product of 5mC in iAs-mediated carcinogenesis is unknown. Here we assess the hydroxymethylome in iAs-transformed cells, showing that dynamic modulation of hydroxymethylated DNA is associated with specific transcriptional networks. Moreover, this pathologic iAs-mediated carcinogenesis is characterized by a shift toward a higher hydroxymethylation pattern genome-wide. At specific promoters, hydroxymethylation correlated with increased gene expression. Furthermore, this increase in hydroxymethylation occurs concurrently with an upregulation of ten-eleven translocation (TET) enzymes that oxidize 5-methylcytosine (5mC) in DNA. To …

Characterizing The Requirement Of The Cmi/Trr Compass-Like Complex During Drosophila Development, Timothy Nickels

Master's Theses

The MLR family of COMPASS-like complexes are histone methyltransferase complexes that are associated with the activation of gene enhancers. In D. melanogaster, Cara mitad (Cmi, also known as Lpt) and Trithorax related (Trr) are central subunits of a complex orthologous to mammalian Lysine methyltransferase 2 C and D (KMT2C and KMT2D, also known as MLL3 and MLL2/4) that catalyze H3K4 monomethylation. Previous studies have demonstrated that mutations in these genes are associated with cancer and developmental disorders, but the mechanisms by which these alterations contribute to disease states are unknown. The Cmi-containing COMPASS-like complex and orthologous vertebrate complexes have been …

Transient And Permanent Changes In Dna Methylation Patterns In Inorganic Arsenic-Mediated Epithelial-To-Mesenchymal Transition, Meredith Eckstein, Matthew Rea, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Chronic low dose inorganic arsenic exposure causes cells to take on an epithelial-to-mesenchymal phenotype, which is a crucial process in carcinogenesis. Inorganic arsenic is not a mutagen and thus epigenetic alterations have been implicated in this process. Indeed, during the epithelial-to-mesenchymal transition, morphologic changes to cells correlate with changes in chromatin structure and gene expression, ultimately driving this process. However, studies on the effects of inorganic arsenic exposure/withdrawal on the epithelial-to-mesenchymal transition and the impact of epigenetic alterations in this process are limited. In this study we used high-resolution microarray analysis to measure the changes in DNA methylation in cells …

Determining The Role Of Epigenetic Factors In Antifungal Drug Resistance, Abigail R. Gress, Scott D. Briggs, Nina Serratore

The Summer Undergraduate Research Fellowship (SURF) Symposium

Epigenetic factors are proteins that regulate gene expression by altering transcriptional machinery access to nucleosomes, DNA wrapped around histone proteins. Two classes of epigenetic factors are ATP-dependent chromatin remodelers and histone modifiers such as histone methyltransferases (HMTs), proteins that add methyl groups to histone tails. This study focuses on AIF4 (Antifungal-Induced Factor 4), a possible HMT induced upon neutral lipid depletion that we hypothesize is regulating antifungal drug resistance genes. Overexpression of AIF4 results in hypersensitivity to antifungal drugs. Studying epigenetic factors in the yeast Saccharomyces cerevisiae, including AIF4, can lead to better understanding of cell adaptation to their environments …

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 …

Microarray Dataset Of Transient And Permanent Dna Methylation Changes In Hela Cells Undergoing Inorganic Arsenic-Mediated Epithelial-To-Mesenchymal Transition, Meredith Eckstein, Matthew Rea, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

The novel dataset presented here represents the results of the changing pattern of DNA methylation profiles in HeLa cells exposed to chronic low dose (0.5 µM) sodium arsenite, resulting in epithelial-to-mesenchymal transition, as well as DNA methylation patterns in cells where inorganic arsenic has been removed. Inorganic arsenic is a known carcinogen, though not mutagenic. Several mechanisms have been proposed as to how inorganic arsenic drives carcinogenesis such as regulation of the cell׳s redox potential and/or epigenetics. In fact, there are gene specific studies and limited genome-wide studies that have implicated epigenetic factors such as DNA methylation in inorganic arsenic-mediated …

Epigenetic Editing To Validate Findings From Methylome-Wide Association Studies Of Neuropsychiatric Disorders, Robin F. Chan

Theses and Dissertations

DNA methylation is necessary for learning, memory consolidation and has been implicated in a number of neuropsychiatric disorders. Obtaining high quality and comprehensive data for the three common forms of methylation in brain is challenging for methylome-wide association studies (MWAS). To address this we optimized a panel of enrichment methods for screening the brain methylome. Results show that these enrichment techniques approach the coverage and fidelity of the current gold standard bisulfite based techniques. Our MBD-based method can also be used with low amounts of genomic material from limited human biomaterials. Psychiatric disorders have high prevalence and are often chronic …

A Novel Role Of Silibinin As A Putative Epigenetic Modulator In Human Prostate Carcinoma, Ioannis Anestopoulos, Aristeidis P. Sfakianos, Rodrigo Franco, Katerina Chlichlia, Mihalis I. Panayiotidis, David J. Kroll, Aglaia Pappa

School of Veterinary and Biomedical Sciences: Faculty Publications

Silibinin, extracted from milk thistle (Silybum marianum L.), has exhibited considerable preclinical activity against prostate carcinoma. Its antitumor and chemopreventive activities have been associated with diverse effects on cell cycle, apoptosis, and receptor-dependent mitogenic signaling pathways. Here we hypothesized that silibinin’s pleiotropic effects may reflect its interference with epigenetic mechanisms in human prostate cancer cells. More specifically, we have demonstrated that silibinin reduces gene expression levels of the Polycomb Repressive Complex 2 (PRC2) members Enhancer of Zeste Homolog 2 (EZH2), Suppressor of Zeste Homolog 12 (SUZ12), and Embryonic Ectoderm Development (EED) in DU145 and PC3 human prostate cancer cells, …

New Open Conformation Of Smyd3 Implicates Conformational Selection And Allostery, Nicholas Spellmon, Xiaonan Sun, Wen Xue, Joshua Holcomb, Srinivas Chakravarthy, Weifeng Shang, Brian Fp Edwards, Nualpun Sirinupong, Chunying Li, Zhe Yang

Biochemistry and Molecular Biology Faculty Publications

SMYD3 plays a key role in cancer cell viability, adhesion, migration and invasion. SMYD3 promotes formation of inducible regulatory T cells and is involved in reducing autoimmunity. However, the nearly “closed” substrate-binding site and poor in vitro H3K4 methyltransferase activity have obscured further understanding of this oncogenically related protein. Here we reveal that SMYD3 can adopt an “open” conformation using molecular dynamics simulation and small-angle X-ray scattering. This ligand-binding-capable open state is related to the crystal structure-like closed state by a striking clamshell-like inter-lobe dynamics. The two states are characterized by many distinct structural and dynamical differences and the conformational …

Nanobubbles Provide Theranostic Relief To Cancer Hypoxia, Christopher M. Long, Pushpak N. Bhandari, Joseph Irudayaraj

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hypoxia is a common motif among tumors, contributing to metastasis, angiogenesis, cellular epigenetic abnormality, and resistance to cancer therapy. Hypoxia also plays a pivotal role in oncological studies, where it can be used as a principal target for new anti-cancer therapeutic methods. Oxygen nanobubbles were designed in an effort to target the hypoxic tumor regions, thus interrupting the hypoxia-inducible factor-1α (HIF-1α) regulatory pathway and inhibiting tumor progression. At less than 100nm, oxygen nanobubbles act as a vehicle for site-specific oxygen delivery, while also serving as an ultrasound contrast agent for advanced imaging purposes. Through in vitro and in vivo studies, …

Epigenetic Characterization Of Human Retina Cells, Nicholas R. Dunham

Senior Honors Projects, 2010-2019

DNA methylation is an epigenetic modifier that modulates gene expression in plant and vertebrate genomes. The aim of this study was to characterize the role of DNA methylation in the human retina, particularly within rod and cone photoreceptor retinal neurons. Previous studies investigating DNA methylation in murine retinal cells and retina-derived human retinoblastoma immortalized cell culture lines demonstrate an inverse relationship between DNA methylation and transcriptional activity. Here, we used gene-specific bisulfite pyrosequencing analysis to measure DNA methylation in the genomes of human ocular cells in an effort to characterize the role of this important epigenetic modifier. These results can …

Epigenetic Regulation Of Gene Expression During Spermatogenesis, Karishma Nayak

Senior Honors Projects

In the US livestock production industry, improving reproductive efficiency will improve animal welfare and maintain reasonable costs of meat and milk for consumers. In recent research, abnormalities in epigenetic markers in sperm during spermatogenesis, has been linked to male subfertility in many species. Epigenetics is the study of changes in organisms caused by modifications of gene expression, including DNA methylation, rather than alteration of the genetic code itself. When this process is disturbed, it can negatively impact semen therefore decreasing its fertility. Through further research on how DNA methylation influences gene expression during spermatogenesis and its impact on sperm quality, …

Preeclampsia: The Roles Of Acute Inflammation And Intrauterine Stress, Nicholas Parchim

Dissertations and Theses (Open Access)

Preeclampsia (PE) is a severe, acute disease of pregnancy affecting approximately 8% of pregnant women after week 20 of gestation. PE is characterized by hypertension and renal damage reflected by proteinuria and has significant morbidity to both mother and fetus. Maternal symptoms range from headaches, nausea, edema, to visual changes, but once maternal symptoms present, damage to the fetus has begun. Mothers who progress untreated through the disease can also experience a condition called eclampsia characterized by seizure, coma, and, ultimately, death. PE-affected newborns experience features similar to prematurity—abnormal lung and renal development, intrauterine growth retardation (IUGR), and, possibly, fetal …

Involvement Of Parp1 In The Regulation Of Alternative Splicing, Elena Matveeva, John Maiorano, Qingyang Zhang, Abdallah M. Eteleeb, Paolo Convertini, Jing Chen, Vittoria Infantino, Stefan Stamm, Jiping Wang, Eric C. Rouchka, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Specialized chromatin structures such as nucleosomes with specific histone modifications decorate exons in eukaryotic genomes, suggesting a functional connection between chromatin organization and the regulation of pre-mRNA splicing. Through profiling the functional location of Poly (ADP) ribose polymerase, we observed that it is associated with the nucleosomes at exon/intron boundaries of specific genes, suggestive of a role for this enzyme in alternative splicing. Poly (ADP) ribose polymerase has previously been implicated in the PARylation of splicing factors as well as regulation of the histone modification H3K4me3, a mark critical for co-transcriptional splicing. In light of these studies, we hypothesized that …

An Analysis Of The Interaction Between Sin3 And Methionine Metabolism In Drosophila, Mengying Liu

Wayne State University Dissertations

Chromatin modification and cellular metabolism are tightly connected. The mechanism for this cross-talk, however, remains incompletely understood. SIN3 controls histone acetylation through association with the histone deacetylase RPD3. In this study, my major goal is to explore the mechanism of how SIN3 regulates cellular metabolism.

Methionine metabolism generates the major methyl donor S-adenosylmethionine (SAM) for histone methylation. In collaboration with others, I report that reduced levels of some enzymes involved in methionine metabolism and histone demethylases lead to lethality, as well as wing development and cell proliferation defects in Drosophila melanogaster. Additionally, disruption of methionine metabolism can directly affect histone …

Using The Intact Method To Study Pickle In Individual Cell Types, Jacqueline L. Phipps, Daniela N. Martir, Ben Carter, Joe Ogas

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cell differentiation is an essential part of development in multicellular organisms. Cells with identical genomic DNA are able to differentiate into a variety of tissues due to selective expression and repression of genes. This tissue-specific gene expression is enabled in part by proteins called chromatin remodelers, which can move, remove, or restructure histone proteins to restrict or allow physical access to genomic DNA. PICKLE (PKL) is a member of the CHD family of ATP-dependent chromatin remodelers that promotes cellular identity in the plant model organism Arabidopsis thaliana. PKL promotes cell identity by silencing embryonic genes during seed germination by promoting …

Epigenetic Role Of Ptip In Mouse Spermatogenesis, Chengjing Liu

Theses, Dissertations and Capstones

In mammals, spermatogenesis is a biological process inside the testis to produce spermatozoa from spermatogonia. This process is governed by both genetic and epigenetic mechanisms and thus is a powerful system for epigenetic research. Methylation of histone 3 lysine 4 (H3K4) is an epigenetic mark, which has been found to be dynamically modulated in mouse male germ cells during spermatogenesis. Pax2 Transactivation domain Interaction Protein (PTIP) has been recently identified as part of a H3K4 methyltransferase complex. In this study, I hypothesize that PTIP is an essential epigenetic regulator in mouse spermatogenesis. To test this hypothesis, I first established a …

Proximate And Evolutionary Insights Into The Epigenetics Of Posttraumatic Stress Disorder, Levent Sipahi

Wayne State University Dissertations

Posttraumatic stress disorder (PTSD) is an important medical and social condition. Although the vast majority of individuals are exposed to traumatic events within their lifetime, a minority subsequently develop diagnosable PTSD. What underlies differential risk and resiliency in the face of trauma is an ongoing research and clinical question with implications for prevention and treatment. Recent work has revealed a putative role of epigenetic variation and modification - most notably DNA methylation - in the etiology of PTSD. That DNA methylation is stable, yet modifiable in response to lived experiences, makes it a strong candidate to mechanistically explain the ontogeny …

Structural And Functional Characterization Of The Mbd2-Nurd Co-Repressor Complex, Megha Desai

Theses and Dissertations

The MBD2-NuRD co-repressor complex is an epigenetic regulator of the developmental silencing of embryonic and fetal β-type globin genes in adult erythroid cells as well as aberrant methylation-dependent silencing of tumor suppressor genes in neoplastic diseases. Biochemical characterization of the MBD2-NuRD complex in chicken erythroid cells identified RbAp46/48, HDAC1/2, MTA1/2/3, p66α/β, Mi2α/β and MBD2 to comprise this multi-protein complex.

In the work presented in Chapter 2, we have pursued biophysical and molecular studies to describe a previously uncharacterized domain of human MBD2 (MBD2_IDR). Biophysical analyses show that MBD2_IDR is an intrinsically disordered region (IDR). Despite this inherent …

Genome-Wide Profiling Unveils Criticial Functions Of P53 In Human Embryonic Stem Cells, Kadir C. Akdemir

Dissertations and Theses (Open Access)

Embryonic stem cells (ESCs) possess two unique characteristics: infinite self-renewal and the potential to differentiate into almost every cell type (pluripotency). Recently, global expression analyses of metastatic breast and lung cancers revealed an ESC-like expression program or signature, specifically for cancers that are mutant for p53 function. Surprisingly, although p53 is widely recognized as the guardian of the genome, due to its roles in cell cycle checkpoints, programmed cell death or senescence, relatively little is known about p53 functions in normal cells, especially in ESCs. My hypothesis is that p53 has specific transcription regulatory functions in human ESCs (hESCs) that …