Dna Damage Response Activates The Electron Transport Chain And Oxidative Metabolism By Two Parallel Mechanisms, Shreya Nagar

Theses and Dissertations

The DNA damage response (DDR) is an evolutionarily conserved process essential for cell survival. Major part of DDR is coordinated by DNA damage checkpoint (DDC). In addition to DDC, eukaryotic cells also have DNA replication checkpoint (DRC) that is distinct from the DDC and specifically signals slowly progressing or arrested replication forks. DDR involves stalling or arrest of the cell cycle, initiation of DNA repair, and altered regulation of transcription, translation, and the ubiquitin-proteasome system. DDR also triggers transcription shut-off of histone genes. One of the key outcomes of DDC/DRC activation is the increased synthesis of the deoxyribonucleoside triphosphates (dNTPs), …

Overexpression Of Abcc1 And Abcg2 Confers Resistance To Bmn-673, A Poly (Adp-Ribose) Polymerase (Parp) Inhibitors, Qiuxu Teng

Theses and Dissertations

Cancer remains a growing public health challenge worldwide. Although the development of chemotherapies has effectively reduced the cancer death rate and improved patients’ prognosis, the frequent occurrence of multi-drug resistance (MDR) in cancer has caused impairments on the efficacy of many structure-unrelated anticancer agents, leading to treatment failure and recurrence. One of the most common causes of MDR is the overexpression of ATP-binding cassette (ABC) transporters on cancer cell membranes, which transport anticancer drugs out of cancer cells, thereby reducing the intracellular drug concentration. BMN-673 (talazoparib) is a potent poly (ADP-ribose) polymerase (PARP) inhibitor that is approved for BRCA-mutated HER2-negative …

Hydroxyurea Globally Inhibits Rna Synthesis, Destabilizes Mrnas, And Triggers Mec1-Opposed Rnapii Accumulation At 3’ Ends Of Genes, Pritpal Kaur

Theses and Dissertations

My dissertation includes two projects. The first project is focused on the regulation of glycolysis and oxidative metabolism by inducing heme synthesis in cancer cells. The second project deals with the effect of hydroxyurea on RNA synthesis. Heme is an essential cofactor for enzymes of the electron transport chain (ETC) and ATP synthesis in mitochondrial oxidative phosphorylation (OXPHOS). Heme also binds to and destabilizes Bach1, a transcription regulator that controls expression of several groups of genes important for glycolysis, ETC, and metastasis of cancer cells. Since many cancers are characterized by a high glycolytic rate regardless of oxygen availability, targeting …

Gating And Pathogenic Mechanism Of Polycystin Ion Channels, Yan Wang

Theses and Dissertations

Autosomal dominant polycystic kidney disease (ADPKD), one of the most common and life-threatening human genetic diseases, is caused by mutations in PKD1 or PKD2 genes. PKD1 gene encodes PKD1 (also known as polycystin-1 or PC1) protein, which are the founding members of the PKD1 proteins family; while PKD2 encodes TRPP2 (also known as polycystin-2 or PC2) protein, the founding member of the TRPP subfamily. PKD1 family consists of PKD1, PKD1L1, PKD1L2, PKD1L3, and PKDREJ. Whereas the TRPP subfamily includes: TRPP2, TRPP3, and TRPP5. Proteins in PKD1 and TRPP families are collectively called polycystins. TRPP proteins can either form homotetrameric ion …

Mancozeb Exposure Results In Oxidative Stress And Disruption Of Mitochondrial Complexes Iii & Iv In Transformed Human Colon Cells, Amanda Dhaneshwar

Theses and Dissertations

The ethylene bisdithiocarbamate pesticides, a subclass of the dithiocarbamate pesticides, are broad spectrum organometallic fungicides used on a variety of crops. The fungicide Mancozeb is comprised of an ethylene bisdithiocarbamate backbone complexed to the metals manganese and zinc. Ingestion of food containing pesticide residue and occupational exposure are common routes of Mancozeb exposure. Previous work demonstrated that Mancozeb exposure to HT-29 colon cancer cells resulted in cytotoxicity, apoptosis, and disruption of mitochondrial complex I, II, and V activity. The current study investigated the effect of Mancozeb exposure on mitochondrial complex III and IV activity and oxidative stress parameters in the …

Insight Into Eleutherodactylus Coqui Resilience And Anuran Hypoxia Tolerance Utilizing Pincho, Randy Ortiz

Theses and Dissertations

The onset of high-throughput RNA-sequencing (RNA-seq) technology allowed research into transcriptomics to accelerate exponentially aided by the rapid advancement of bioinformatic pipelines. The Pincho workflow, my first research endeavor, is a transcriptomic workflow developed to create an avenue of high-quality reconstructions from RNA-seq data. High-quality reconstruction standards entail longer transcripts, more complete transcripts, and more raw data utilization. We have discovered an ideal trio of assemblers between transABySS, rnaSPAdes and TransLiG that would best reconstruct next-generation sequencing data according to these standards. We utilized Pincho to drive two distinct experiments: (1) exploring the genetic basis for the successful invasion of …

Interferon Gamma Signaling In Ovarian Cancer Cells, Bijaya Gaire

Theses and Dissertations

Interferon gamma (IFNγ) is a pleiotropic cytokine that can have, depending on the cellular and molecular context, both anti-tumor and pro-tumorigenic functions. IFNγ expression can be induced in cancer cells in response to radiation therapy or immune checkpoint blockade used in cancer treatment. We have previously shown that IFNγ induces expression of the Bcl3 proto-oncogene in ovarian cancer (OC) cells, resulting in their increased proliferation and migration, but the mechanisms are unknown. Here, I demonstrate that the IFNγ-induced Bcl3 expression is dependent on JAK1 and STAT1 signaling, and on p65 NFkB. Furthermore, my data show that the IFNγ-induced Bcl3 expression …

Cytotoxicity Of Copper (Ii) Octanoate On Mouse Hippocampal Astrocytes, Ali A. Shohatee

Theses and Dissertations

Copper, as an essential trace element, is crucial for various biological processes but has also been utilized as a constituent of various pesticides for decades. Copper (II) octanoate is a pesticide utilized as a fungicide and is approved for use in the production of certified organic foods. Previous studies have implicated copper as an inducer of oxidative stress and activator of the Nrf2-ARE pathway. Nrf2 is essential in regulating the transcription of various genes to alleviate toxicity such as those involved in glutathione synthesis and detoxification. Due to the limited toxicological data, this study into the potential induction of oxidative …

Regulation Of P53 By Trpm6 And Trpm7, Thomas Whitbread

Theses and Dissertations

TRPM6 and TRPM7 are two divalent metal cation channels that also possess a serine/threonine kinase domain. They both play critical roles in cellular and organismal metal homeostasis, and are necessary for proper embryonic development and human health. They may function independently in homomeric units, or act together as heterotetramers that display unique characteristics compared to the homomeric channels. These channel-kinases have increasingly been linked to cancer, displaying altered expression levels in a variety of human cancers and contributing to disease progression. Prior work has shown that TRPM6 and TRPM7 can participate in cancer-related signaling pathways. Here, the potential for TRPM6 …

Evaluating The Influence Of Concurrently Available Non-Drug Reinforcers On Drug Reinforcement Using Sophisticated Preclinical Models Of Substance Use Disorder, Madison M. Marcus

Theses and Dissertations

The maladaptive allocation of behavior towards cocaine and away from other concurrently available non-drug reinforcers (e.g., family, health, work, etc.) is a key characteristic of cocaine use disorder (CUD) that is embedded into multiple diagnostic criteria for CUD. Accordingly, basic research conducted in a drug-vs-food “choice” context has improved our fundamental knowledge of the behavioral and neurobiological mechanisms of drug reinforcement. However, to date, these preclinical studies have only been conducted with food as the alternative reinforcer. The extent to which other non-drug reinforcers compete with cocaine-taking behavior is unknown. The studies in this dissertation establish two sophisticated discrete-trial cocaine-vs-alternative …

Climate, Physiology, And Distributions: The Role Of Thermal Physiology In Biological Invasions, Sean D. Powers

Theses and Dissertations

Climate is a primary factor influencing species range dynamics, particularly for ectotherms whose body temperature is closely tied to the surrounding conditions. While range shifts of ectotherms are attributed to climate warming, the mechanism driving these shifts are not well understood. Studies in macrophysiology demonstrate that the interaction of climate with thermal physiology plays a key role in determining large-scale spatial and temporal patterns for many temperature-sensitive physiological traits. This work has revealed a clear relationship between thermal tolerance breadth and range size. However, more recent analyses of this relationship demonstrate that thermal tolerance breadth only provides a partial explanation …

Determining The Effects Of Water Quality On Stream Metabolic Function Of Urban Stream Corridors In Columbus, Georgia, Md Abu Raihan

Theses and Dissertations

Urbanization alters streams, disrupting their natural habitat and inducing changes in nutrient dynamics and primary productivity. These human-induced interventions diminish ecological structure, homogenizing once-diverse ecosystems and posing a risk of impairment or destruction. Continuous monitoring of stream ecosystem metabolism emerges as an essential tool for a comprehensive understanding and effective intervention in response to these challenges. This study delves into the intricate dynamics of nutrient levels and productivity within the urbanized context of the Weracoba Creek watershed located in Columbus, Georgia, USA. Through a cross-sectional study, we explore spatial and temporal variations in nutrient concentrations (NH4, NO3, PO4, TP, TN) …

Csi Botany: Dna Barcode “Fingerprints” Identify Cryptic Urban Flora, Luis R. Vega

Theses and Dissertations

As short genomic markers, DNA barcodes can play a role in conservation by identifying cryptic species and hybrids when morphological approaches fall short. Here we present our application of barcodes to the identities of two wetland taxa as part of an ongoing floristic inventory of Van Cortlandt Park (VCP), Bronx, NY. Previous barcode data by Marriott et al. (2018) identified the VCP lake water lily as the exotic Nymphaea alba, rather than the native N. odorata as historically described. In addition, cattails in the park were historically identified as the native Typha latifolia and the exotic T. angustifolia …

Evaluating How Acidic Solutions Affect The Microhardness Of Bioceramic Sealers, Colton Fischer

Theses and Dissertations

Introduction: With growing use of bioceramic sealers (BCS) in root canal therapy, there have been challenges when retreating BCS cases. Weak acids may be effective in removing BCS and their efficacy as a solvent can be measured by their influence on the microhardness of BCS. Microhardness can be used as an indirect measurement of material hardness. The purpose of this study was to investigate the microhardness of BCS when placed in contact with various acidic solutions to assess their potential use as a solvent for retreatment procedures.

Methods: EndoSequence BC Sealer (Brasseler USA) was injected into four 10 × 3mm …

Dune Building Dynamics Impact Cross-Island Connectivity And Barrier Island Characteristics, Alexander Sabo

Theses and Dissertations

Located at the land-sea interface, barrier islands are important protective features that reduce wave energy and erosion from mainland areas. Further, barrier islands provide habitat for many different organisms and serve as popular areas for recreation and tourism. As sandy landforms, barrier islands are easily disturbed, but often recover after disturbance as a result of island plant communities, specifically dune building grasses. Disturbance on barrier islands is driven by storms, tides, and overwash events. After disturbance has occurred, dune grasses colonize the dunes allowing for dune building and habitat restoration. On the Virginia barrier islands, there are three dominant dune …

The Type Iv Pilus Secretin Bfpb: Structural Analysis And Binding Interactions, Janay I. Little

Theses and Dissertations

Enteropathogenic Escherichia coli (EPEC) causes severe diarrhea in young children. The type IV pilus (T4P) of EPEC, known as the bundle-forming pilus (BFP), plays an important role in EPEC pathogenesis. T4Ps are a family of surface appendages that are important for adhesion, colonization, biofilm formation, virulence, twitching motility and many other functions. One essential component of the BFP system is the secretin, BfpB. Secretins are a large family of integral outer membrane proteins found in T4Ps as well as type II and type III secretion systems, and filamentous phages. Details of the secretin structure have been limited to the overall …

Quantifying Insect Emergence In Tidal Freshwaters And The Importance Of Aquatic Prey In Wetland-Dependent Songbird Diet, Samantha L. Rogers

Theses and Dissertations

Insectivorous birds and their arthropod prey are experiencing widespread population declines, driven largely by anthropogenic disturbance and climate change. For wetland-dependent insectivores that consume a mixture of terrestrial and aquatic insects, understanding the availability, consumption, and nutritional qualities of aquatic diet subsidies is important for conservation. I use prothonotary warblers (Protonotaria citrea) as a model species throughout this work, because their breeding season aligns with aquatic insect emergence and they include aquatic insects when provisioning nestlings. In the first chapter, I estimate aquatic insect emergence from tidal freshwaters, which are understudied compared to nontidal systems. Using continuous field …

Modulation Of Opioid-Induced Respiratory Depression By Stimulants And Their Associated Monoaminergic Receptor Mechanisms In Mice Using Whole Body Plethysmography, Harrison J. Elder

Theses and Dissertations

Opioid overdose and associated deaths involving opioid-induced respiratory depression (OIRD) began to accelerate beginning in 2015 with the emergence of illicitly manufactured fentanyl and its analogs and currently represents one of the most significant public health challenges in the United States. The increases in overdose deaths have occurred despite the increased availability of the opioid overdose reversal agent, naloxone, to first responders and the public. This new phase of the opioid epidemic has been paralleled by substantial growth in the co-use of opioids with stimulants, particularly methamphetamine. The objective of this dissertation is to ascertain whether fentanyl is particularly resistant …

The Hepatic Immunological Pattern Shaped By Dominant-Subdominant Cellular Interactions Creates A Collective Function Beyond The Function Of Each Cellular Constituent To Orchestrate Progression Of Hepatocellular Carcinoma, Nicholas J. Koelsch

Theses and Dissertations

Abundance of data on the role of inflammatory immune responses in the progression or inhibition of hepatocellular carcinoma (HCC) has failed to offer a curative immunotherapy for HCC. This is largely because of taking reductionist approaches and missing the collective function of the hepatic immune system by focusing on specific immune cell types. To this end, we propose that focusing on the dominant-subdominant patterns of the immune cells would allow understanding of the mechanism by which a collective immune function emerges. To identify the collective immune function through a systems immunology perspective, we performed high-throughput analysis of snRNAseq data collected …

Exploring The Relationship Between The Epigenome And Metabolism In Mycn-Amplified Neuroblastoma, Krista M. Dalton

Theses and Dissertations

High risk neuroblastoma (NB) is responsible for nearly 15% of all cancer related deaths in the pediatric population. The transcription factor MYCN is the most studied oncogene in NB, automatically conferring high-risk and has been found to be difficult to target. One way that MYCN amplification in NB functions to support tumorigenicity is through altered metabolism, satisfying the demand for rapid proliferation by increasing the nutrient flux through biosynthetic pathways. We performed an unbiased screen on select metabolic targeted therapy combinations and correlated sensitivity with over 20 subsets of cancer. We found that MYCN-amplified NB is hypersensitive to the …

Kpt-330 Synergizes With Everolimus To Reduce Mtorc1-Overactive Basal-Like Triple-Negative Breast Cancer Brain Metastasis Burden, Aaron D. Valentine

Theses and Dissertations

Triple-negative breast cancer (TNBC), a highly metastatic breast cancer subtype, accounts for approximately 20% of all breast cancer diagnoses. Basal-like TNBC is notably difficult to treat due to the lack of actionable drug targets such as estrogen and progesterone receptors, as well as HER2. Due to the deficiency in TNBC-targeting drugs that are able to cross the blood-brain barrier (BBB) for breast-to-brain metastasis, there is a need to develop novel BBB-permeable treatments. After preliminary testing, KPT-330 (XPO1 inhibitor) and everolimus (FKBP1A/mTOR inhibitor) were selected as drug candidates for this study. Patient-derived xenograft (PDX) models for in vitro and in vivo …

Studying Gene Function In Streptococcus Sanguinis Using Rna-Sequencing Analysis, Ahmed Ismail

Theses and Dissertations

The oral cavity hosts hundreds of bacterial species, amongst them are the Streptococci family. More specifically, S. sanguinis is a benign bacteria in the oral cavity to protect the tooth surface from S. mutans. which is a pathogen causing dental caries. While S. sanguinis is harmless in the oral cavity, it becomes pathogenic once entering the bloodstream and causing Infective Endocarditis (IE). To further study S. sanguinis and eventually develop an effective drug to treat IE caused by S. sanguinis, a gene expression study was conducted. In order to study gene expression, RNA-sequencing was conducted, and appropriate methods to remove …

Evaluation Of Spliceai For Improved Genetic Variant Classification In Inherited Ophthalmic Disease Genes, Melissa Reeves

Theses and Dissertations

ABSTRACT

EVALUATION OF SPLICEAI FOR IMPROVED GENETIC VARIANT CLASSIFICATION IN INHERITED OPHTHALMIC DISEASE GENES

By Melissa Jean Reeves, Ph.D.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2023

Major Director: Melissa Jamerson, PhD, MLS(ASCP)

Associate Professor, Department of Medical Laboratory Sciences

Inherited ophthalmic diseases impact individuals around the globe. Inherited retinal diseases (IRDs) are the leading cause of blindness in individuals aged 15 to 45. The personal, social, and economic impact of vision loss is profound. Due to individual differences, symptoms can be variable, and …

Mechanistic Insight Into Traumatic Brain Injury Induced Neuronal Membrane Disruption: Cathepsin B Relocalization And A Neun Negative Cortical Neuron Subpopulation, Martina L. Hernandez

Theses and Dissertations

Traumatic brain injury (TBI) is a mechanical insult to the head that leads to brain damage and, in turn, causes long-term sensory, motor, cognitive, and affective dysfunction. Diffuse pathologies seen following such injury are associated with these life-altering outcomes that impact the daily lives of TBI survivors. The diffuse pathology that this body of work focuses on is neuronal membrane disruption; it is characterized by increased permeability of the neuron’s plasma membrane. Moreover, our lab had previously found that membrane disruption is exacerbated with intracranial pressure (ICP) elevation. We set out to measure the duration of membrane disruption following injury …

Characterizing 3-O-Sulfation-Induced Novel Compact Topologies In Heparan Sulfate And Their Interactions With Proteins, Samuel Holmes

Theses and Dissertations

Heparan sulfate (HS) is highly-charged, linear polysaccharide that interacts with numerous proteins in humans as consituents of proteoglycans. The action of sulfotransferase enzymes during the biosynthesis of HS can generate a combinatorially massive library of differentially sulfated sequences. Furthermore, the number and position of these sulfate groups are key to their biological activity, modulating their selectivities for certain proteins at the cell surface or ECM. The installation of a sulfate on the C3 hydroxyl of a glucosamine residue in HS represents the rarest of the sulfations, despite the HS 3-O-sulfotransferase (3OST) family being the most diverse of the other sulfotransferases. …

Mitigation Of Nicotine Reward And Withdrawal By The N-Acyl Amino Acids: N-Oleoyl Glycine And N-Oleoyl Alanine, Kimberly Karin

Theses and Dissertations

A growing body of research is exploring the efficacy of N-acyl amino acids (N-oleoyl glycine; OlGly and N-oleoyl alanine; OlAla) in rodent models of drug reward and dependence. In particular, OlGly attenuated the reinforcing effects of nicotine in the mouse nicotine-induced conditioned place preference (CPP) paradigm and reduced somatic and affective signs of mecamylamine-precipitated withdrawal in nicotine-dependent mice. Based on the addition of a methyl group on the head group, OlAla was proposed to have increased metabolic stability compared to OlGly. While OlAla has been assessed in assays of reward and withdrawal of opioids, cocaine, and …

Quantitative And Molecular Genetic Analyses Of Brain Structure, Substance Use, And Posttraumatic Stress Phenotypes: Data From Children, Adolescents And Adults, Daniel Bustamante

Theses and Dissertations

Abstract

QUANTITATIVE AND MOLECULAR GENETIC ANALYSES OF BRAIN-IMAGING, SUBSTANCE USE, AND POSTTRAUMATIC STRESS PHENOTYPES: DATA FROM CHILDREN, ADOLESCENTS AND ADULTS

By Daniel Bustamante, B.S., B.A.

Doctoral dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Integrative Life Sciences – Behavioral and Statistical Genetics at Virginia Commonwealth University.

Virginia Commonwealth University, 2023.

Dissertation directors: Michael C. Neale, Ph.D., Banks Distinguished Professor of Psychiatry & Human and Molecular Genetics; and, Ananda B. Amstadter, Ph.D., Professor of Psychiatry, Psychology, & Human and Molecular Genetics.

Substance use (SU) and posttraumatic stress disorder (PTSD) phenotypes are comorbid, share …

Treponema Denticola Synthesizes C-Di-Amp And Encodes The Cdaa-Type Diadenylate Cyclase Cdaa, Claire R. O'Brien

Theses and Dissertations

Periodontitis is a form of oral disease characterized by dysbiosis of the oral microbiome, leading to inflammation, bone resorption, and in severe cases, entire tooth loss, affecting 42% of adults in the US. One of the bacteria most associated with periodontal disease progression is Treponema denticola (Td), an oral spirochete which inhabits the mouth in small quantities during health but which can dominate the biofilms that form during periodontal disease. The ability of Td to survive in a disease environment and contribute to the progression of disease requires the use of robust signaling networks. Analysis of Td cultures …

Tgif1 Physiological Levels Limit Β-Cell Distress And Neonatal Diabetes, Creighton J. Friend

Theses and Dissertations

TGIF1 belongs to the superfamily of homeodomain proteins, which regulate a wide variety of biological functions, including cell stemness and specification of cell fate during early development. Perhaps surprisingly, we found that enforced expression in pancreatic progenitor cells during embryogenesis resulted in severe diabetes, hinting at the possibility that TGIF1 might regulate pancreas development. Subsequent genetic experiments targeting β-cells showed that TGIF1 affected β-cell function and homeostasis. Transcriptomic analysis revealed that TGIF1 expression inhibits the expression of essential components of UPR signaling, underscoring a potential mechanism in which TGIF1 disrupts protein folding and secretion. Congruently, TGIF1 expression led to a …

Incorporating A Developmental Perspective Into Gene Identification Models For Alcohol Use Behaviors, Nathaniel S. Thomas

Theses and Dissertations

Frequent alcohol use can lead to alcohol use disorder, which accounts for three million deaths and over 133 million life years lost to disability and death worldwide per year. Alcohol use behaviors unfold across development, beginning with initiation of drinking and progressing through various escalating stages of use. Alcohol use behaviors are also under genetic influence. Genome-wide association represents the state-of-the-science statistical methodology for identifying genes associated with alcohol use outcomes. However, contemporary genome-wide association study (GWAS) methods typically do not account for variability in genetic effects throughout development. In this project, I applied novel multivariate genomic methods to combine …