Biochemistry Commons^™

Exosomal-Long Non-Coding Rnas Journey In Colorectal Cancer: Evil And Goodness Faces Of Key Players, Nehal I. Rizk, Ahmed I. Abulsoud, Mohamed M. Kamal, Dina H. Kassem, Nadia M. Hamdy

Pharmacy

Exosomes are nano-vesicles (NVs) secreted by cells and take part in cell-cell communications. Lately, these exosomes were proved to have dual faces in cancer. Actually, they can contribute to carcinogenesis through epithelial-mesenchymal transition (EMT), angiogenesis, metastasis and tumor microenvironment (TME) of various cancers, including colorectal cancer (CRC). On the other hand, they can be potential targets for cancer treatment. CRC is one of the most frequent tumors worldwide, with incidence rates rising in the recent decades. In its early stage, CRC is asymptomatic with poor treatment outcomes. Therefore, finding a non-invasive, early diagnostic biomarker tool and/or suitable defender to combat …

Determining The Effects Of Chemical Exposure On Hepatocyte Mitochondrial Networks And Cell Viability, Bethany Eaton

All Master's Theses

Mitochondria are cellular organelles that are becoming more recently studied. One of their main functions is the production of energy through cellular respiration, which is crucial to cell life. However, they are also associated with numerous disease states. It is hypothesized that reactive oxygen species (ROS), largely produced in mitochondria, induce oxidative stress and affect mitochondrial morphology along with cell viability. This study compares chemical exposure of menadione, an ROS producer, and phthalates (plasticizers) on two mouse hepatocyte cell lines to determine the effects they have on mitochondrial morphology and cell viability. Three experiments were performed to analyze the effects …

The Role Of Shoc2 In Embryonic Development, Rebecca G. Norcross

Theses and Dissertations--Molecular and Cellular Biochemistry

The canonical ERK1/2 signaling cascade regulates cellular functions critical in vertebrate embryonic development such as proliferation, apoptosis, differentiation, and migration. Thus, its signals are controlled by a variety of mechanisms. Scaffold proteins are considered central to the mechanisms regulating the transmission of the ERK1/2 signals. Yet, their functions in development nor the molecular mechanisms by which they exert their control are not well understood.

This study focuses on the essential regulator of ERK1/2 signals during development – the scaffold protein Shoc2. Loss of Shoc2 leads to early embryonic lethality in mice and zebrafish. Germline mutations in the shoc2 gene result …

A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy

Theses and Dissertations--Molecular and Cellular Biochemistry

Toxoplasma gondii is an opportunistic, protozoan parasite of all warm-blooded animals, infecting roughly one-third of humans worldwide. Humans acquire infections by consuming T. gondii tissue cysts in undercooked meat or from oocysts shed in cat feces. Encysted parasites convert into rapidly growing tachyzoites that disseminate throughout the body, defining the acute phase of infection. Under host immune pressure, tachyzoites convert into bradyzoites that populate tissue cysts found in CNS or muscle tissue and persist for the lifetime of the host, defining the chronic phase of infection. Tissue cysts are responsible for transmission via carnivory, but also possess the ability to …

Development Of Novel Pyridazine Derivatives And Drug Delivery Systems Against Dengue, Janae A. Culmer

College of Graduate Studies: Theses & Dissertations

The lack of approved vaccines, medications and treatment regimens has significantly contributed to the rapid spread of mosquito-borne viruses such as Dengue and Zika virus. The complex immunopathology of these viruses presents limitations for the development and implementation of a definitive, safe and effective approach to combat infections.Previous research has demonstrated that vector control strategies such as the elimination of larval habitats, larviciding with insecticides, the use of biological agents and the application of adulticides have been unsuccessful in the reduction of viral transmission leading to the need for the continued development of antivirals. This research proposes an approach for …

Tissue And Sex-Specific Rna Editing During Induced Acute Inflammation, Claire E. Nichols

Graduate Theses/Dissertations

A-to-I RNA editing is a process where select adenosine (A) nucleotides are deaminated by an editing enzyme, ADAR, to become inosines (I) in RNA transcripts. RNA editing can affect the sequence of the encoded protein and the regulation of the RNA. ADAR1 also plays a role in regulating innate immunity and its expression is upregulated during inflammation. Current data on the effects of increasing ADAR1 on RNA editing is limited, and most studies are completed only in male animals. We are interested in expanding RNA editing data to include female animals. Lipopolysaccharide (LPS) was used to induce acute inflammation and …

Ero1Α Promotes Tumorigenesis In Egfr Driven Nsclc, Brennan D. Johnson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Non-Small Cell Lung Cancer (NSCLC) is a pulmonary malignancy most commonly associated with smoking, or exposure to asbestos or Radon. Approximately, 1.6 Million deaths occur each year due to lung cancer. Lung Cancer is categorized by two main types, Small Cell Lung Cancer (SCLC) and NSCLC. NSCLC accounts for approximately 85% of all lung cancer cases and is subdivided into three sub-categories: Adenocarcinoma, the most common and leading cause of death in the United States; Squamous Cell Carcinoma (SCC), and Large Cell Carcinoma. Though NSCLC treatment regimens have shown increasing clinical benefit over the last two decades with targeted therapies. …

An Investigation Into The Mechanism Of Proteasome Dysfunction In Neurodegenerative Disease And The Biological Impact Of Proteasome Hyperactivation In C. Elegans, Raymond T. Anderson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Aging is an inevitable process that occurs as humans grow older. It is characterized by the chronological accumulation of cellular damage over time leading to functional decline as an organism grows older. Several processes are thought to contribute to the aging phenomenon, but one of the most prolific of these is the disruption of protein homeostasis (proteostasis). The collapse of proteostasis can lead to accelerated aging and the development of age-related diseases including devastating neurodegenerative diseases (NDs) like Alzheimer and Parkinson disease. Virtually all NDs are characterized by the buildup of proteins in and around neurons resulting in neuronal death …

Protein Charge Parameters That Influence Stability And Cellular Internalization Of Polyelectrolyte Complex Micelles, Rachel A. Kapelner, Rachel S. Fisher, Shana Elbaum-Garfinkle, Allie C. Obermeyer

Advanced Science Research Center

Proteins are an important class of biologics, but there are several recurring challenges to address when designing protein-based therapeutics. These challenges include: the propensity of proteins to aggregate during formulation, relatively low loading in traditional hydrophobic delivery vehicles, and inefficient cellular uptake. This last criterion is particularly challenging for anionic proteins as they cannot cross the anionic plasma membrane. Here we investigated the complex coacervation of anionic proteins with a block copolymer of opposite charge to form polyelectrolyte complex (PEC) micelles for use as a protein delivery vehicle. Using genetically modified variants of the model protein green fluorescent protein (GFP), …

Alternative Splicing Regulates The Innate Immune Response To Viral Infection, Luke A. White

Graduate Student Theses, Dissertations, & Professional Papers

Rift Valley fever virus (RVFV) is a mosquito-borne RNA virus that infects humans and livestock in sub-Saharan Africa and the Arabian peninsula, causing disease ranging from a mild flu-like illness to liver damage, blindness, hemorrhagic fever, death, and, especially in livestock animals, high rates of abortive pregnancies. There is no approved vaccine for RVFV, and as a disease with a high rate of spread that causes severe illness, it is listed as a Category A pathogen by the USA CDC. A better understanding of RVFV’s molecular virology will be instrumental to combating RVFV as climate change causes its mosquito host …

A Pkcα-Mediated Growth Suppressive Mek-Erk Signaling Axis In Intestinal Epithelial Cells, Navneet Kaur

Theses & Dissertations

Members of the protein kinase C (PKC) family of serine/threonine kinases are involved in regulation of fundamental cellular functions, including proliferation, differentiation, survival, migration, and transformation. Increasing evidence points to anti-proliferative and tumor suppressive role of PKCs. Our laboratory and others have reported that the classical PKC isozyme, PKCαnegatively regulates proliferation and tumorigenesis in the intestinal epithelium. Our laboratory has further determined that PKCα signaling induces a program of cell cycle withdrawal in intestinal epithelial cells that involves downregulation of the pro-proliferative proteins, cyclin D1 and Id1, and upregulation of the cyclin dependent kinase (CDK) inhibitor, p21^Cip1. Unexpectedly, …

Nuclear Receptor Coactivator 3 In Endoplasmic Reticulum Stress And Stress Granule Dynamics In Pancreatic Cancer, Andrew Kisling

Theses & Dissertations

Pancreatic cancer is predicted to be the second-leading cause of cancer-related deaths within the next decade. Nuclear receptor coactivator 3 (NCOA3/SRC3/AIB1) regulates an array of metabolic and signaling pathways and has been established by our group and others as a critical regulator pancreatic cancer progression and metastasis. A recent study demonstrated NCOA3 regulation by the IRE1α-XBP1 axis of the unfolded protein response (UPR), suggesting a link between NCOA3 and cellular stress management. Furthermore, NCOA3 has been shown to directly bind to a scaffolding protein of stress granules (SGs). Since SG assembly is regulated by the UPR, we hypothesized that NCOA3 …

Functional Characterization Of Cancer-Associated Dna Polymerase Ε Variants, Stephanie R. Barbari

Theses & Dissertations

Replicative DNA polymerases ε (Polε) and δ (Polδ) achieve high fidelity DNA synthesis through a precise balance of polymerization and exonucleolytic proofreading. Errors that escape proofreading are corrected by DNA mismatch repair (MMR). Ultramutated human cancers with proficient MMR carry alterations in the exonuclease domain of Polε, which were initially predicted to abolish proofreading. However, functional studies in yeast of the most recurrent Polε-P286R variant suggested defects beyond a loss of exonuclease activity. Indeed, biochemical analysis of the yeast Polε-P286R analog revealed increased polymerization capacity in addition to decreased proofreading, which enables efficient mismatch extension and bypass of replication-blocking non-B …

Molecular Mechanisms Of Aberrant Protein Glycosylation In Pancreatic Cancer Stemness And Metastasis, Frank Leon

Theses & Dissertations

A myriad of genetic and other abnormal changes underlies the aggressiveness and dissemination properties observed in pancreatic cancer (PC). Aberrant protein glycosylation is a commonly observed feature in PC. The modification of protein O-glycosylation is mediated by glycosyltransferases, which attach and sequentially elongate monosaccharides on Serine/Threonine (Ser/Thr) motifs. Aberrant glycosylation is recognized as an emerging hallmark of cancer where a disruption in normal glycosylation results in irregular O-glycans.

This dissertation research has investigated the consequences of aberrant protein glycosylation on stemness and enhancement of metastatic properties in pancreatic ductal adenocarcinoma (PDAC). Several publications have reported aberrant O-glycosylation increases in oncogenic …

Engineering Fluorescently Labeled Human Fibroblast Growth Factor One Mutants And Characterizing Their Photophysics Properties Towards Designing Fret Assays, Mamello Mohale

Graduate Theses and Dissertations

Human fibroblast growth factor one (hFGF1) belongs to a family of 22 FGF members produced by fibroblast cells. Cell signaling during physiological processes of angiogenesis and wound healing occurs when hFGF1 binds to its receptor (FGFR). However, when heterogenous homeostasis is not maintained, fibroblast cells exhibit excessive proliferation which can lead to a myriad of cancers. smFRET is an ultrasensitive distant dependent (1-10 nm) technique capable of resolving such heterogeneity in structural dynamics and binding affinities (Kd). Therefore, we successfully designed and characterized fluorescently labeled hFGF1 tracers which span the visible light region of the electromagnetic spectrum for use in …

Investigating Effects Of Microenvironmental Stress On Cell Metabolism Using Multiphoton Imaging, Lisa Rebello

Graduate Theses and Dissertations

Resistance to therapy in cancer is a major cause of poor prognosis in patients. Tumor hypoxia plays an active role in mediating treatment resistance and has been linked to metastases and metastatic potential in cancer. Our research focused on three objectives: i) To understand metabolic effects of chronic and intermittent hypoxia in murine breast cancer cells and its affiliation with metastatic potential ii) To identify the metabolic changes associated with radiation therapy in a panel of radiosensitive and radioresistant human head and neck cancer cells and iii) to monitor the changes in cell metabolism associated with gain of treatment resistance. …

Physiological Roles Of Mammalian Transmembrane Adenylyl Cyclase Isoforms, Katrina F. Ostrom, Justin E. Lavigne, Tarsis F. Brust, Roland Seifert, Carmen Dessauer, Val J. Watts, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

Adenylyl cyclases (ACs) catalyze the conversion of ATP to the ubiquitous second messenger cAMP. Mammals possess nine isoforms of transmembrane ACs, dubbed AC1-9, that serve as major effector enzymes of G protein-coupled receptors. The transmembrane ACs display varying expression patterns across tissues, giving potential for them having a wide array of physiologic roles. Cells express multiple AC isoforms, implying that ACs have redundant functions. Furthermore, all transmembrane ACs are activated by Gα_s so it was long assumed that all ACs are activated by Gα_s-coupled GPCRs. AC isoforms partition to different microdomains of the plasma membrane and form …

Fusion And Beyond: Satellite Cell Contributions To Loading-Induced Skeletal Muscle Adaptation, Kevin A. Murach, Christopher S. Fry, Esther E. Dupont-Versteegden, John J. Mccarthy, Charlotte A. Peterson

Health, Human Performance and Recreation Faculty Publications and Presentations

Satellite cells support adult skeletal muscle fiber adaptations to loading in numerous ways. The fusion of satellite cells, driven by cell-autonomous and/or extrinsic factors, contributes new myonuclei to muscle fibers, associates with load-induced hypertrophy, and may support focal membrane damage repair and long-term myonuclear transcriptional output. Recent studies have also revealed that satellite cells communicate within their niche to mediate muscle remodeling in response to resistance exercise, regulating the activity of numerous cell types through various mechanisms such as secretory signaling and cell-cell contact. Muscular adaptation to resistance and endurance activity can be initiated and sustained for a period of …

The Structural And Functional Role Of Photosensing In Rgs-Lov Proteins, Zaynab Jaber

Dissertations, Theses, and Capstone Projects

Light provides organisms with energy and spatiotemporal information. To survive and adapt, organisms have developed the ability to sense light to drive biochemical effects that underlie vision, entrainment of circadian rhythm, stress response, virulence, and many other important molecularly driven responses. Blue-light sensing Light-Oxygen-Voltage (LOV) domains are ubiquitous across multiple kingdoms of life and modulate various physiological events via diverse effector domains. Using a small molecule flavin chromophore, the LOV domain undergoes light-dependent structural changes leading to activation or repression of these catalytic and non-catalytic effectors. In silico analyses of high-throughput genomic sequencing data has led to the marked expansion …

Indicators Of Senescence And Their Relationship With The Antioxidant Response Element In Ovarian Cancer Cells—Toward A More Encompassing View Of Enzyme Activity Levels In Cells, Shaniqua Analycia Hayes

LSU Doctoral Dissertations

Enzymes and other related proteins are promising targets as biomarkers for cancer diagnostics, and it is therefore important to be able to quantify intracellular enzyme activity levels, not just presence of enzyme. Thus, there is a great need for the development of methods that offer spatiotemporal quantification of intracellular enzyme activity levels in respiring 2- and 3-dimensional cultures or their sample-processed variants. Previous studies have demonstrated that ß-gal is upregulated in senescence and in select ovarian cancers, and its expression/activity is upregulated when cells are under oxidative stress conditions. To that end, the primary goal of this work was to …

Anatomy And Physiology Preparatory Course Textbook (2nd Edition), Carlos Liachovitzky

Open Educational Resources

The goal of this preparatory textbook is to give students a chance to become familiar with some terms and some basic concepts they will find later on in the Anatomy and Physiology course, especially during the first few weeks of the course.

Organization and functioning of the human organism are generally presented starting from the simplest building blocks, and then moving into levels of increasing complexity. This textbook follows the same presentation. It begins introducing the concept of homeostasis, then covers the chemical level, and later on a basic introduction to cellular level, organ level, and organ system level. This …

Cellular Toxicity Of Malonato (Ethylenediamine) Platinum (Ii) In Models Of Cancer, Sidikat Olanrewaju Olajuwon

Masters Theses & Specialist Projects

Platinum(II) compounds including the three FDA approved drugs, cisplatin, carboplatin, and oxaliplatin, are composed of two structural components, a leaving ligand, and a non-leaving ligand, each attached to a central platinum(II) atom. All bifunctional platinum compounds studied have similar mechanisms of initiating cell death. However, their efficacy as chemotherapeutics depends on the tissues in which the cancer originates. No model has explained these tissue-specific efficacies. We hypothesized that the efficacies of these platinum compounds vary due to structural differences in the leaving ligands. To test the influence of the leaving ligand on cellular survival, novel platinum compounds were synthesized, and …

Evaluating Bioenergetics And Mitochondrial Dynamics In Patient Fibroblasts With Pathogenic Mitochondrial Dna Mutations Causing Leigh Syndrome, Ajibola Bakare

Graduate Theses and Dissertations

Leigh syndrome (LS) is a rare fatal mitochondrial disorder of infants caused by pathogenic mutations in the nuclear (nDNA) or mitochondrial DNA (mtDNA) leading to mitochondrial dysfunction. The extent to which pathogenic mtDNA variants regulate disease severity in LS is not well understood. The heterogeneous nature of this disorder, based in part by complex mitochondrial genetics, and the nuclear and mitochondrial cross-talk has made it particularly challenging to investigate and develop therapies for treating LS . While the prognosis is poor, several studies are underway to understand the pathophysiology of LS. This dissertation provides a comprehensive structural and functional analysis …

Reconstituting The Cyanobacterial Circadian Clock In Vitro, Pyong Hwa Kim

Dissertations

Cyanobacteria are photosynthetic organisms that are known to be responsible for oxygenating Earth’s early atmosphere. Having evolved to ensure optimal survival in the periodic light/dark cycle on this planet, their genetic codes are packed with various tools, including a sophisticated biological timekeeping system. Among the cyanobacteria is Synechococcus elongatus PCC 7942, the simplest clock-harboring organism with a powerful genetic tool that enabled the identification of its intricate timekeeping mechanism. The three central oscillator proteins—KaiA, KaiB, and KaiC—drive the 24 h cyclic gene expression rhythm of cyanobacteria, and the "ticking" of the oscillator can be reconstituted inside a test tube just …

Role Of Endocytic Machinery Regulators In Egfr Traffic And Viral Entry, Insha Mushtaq

Theses & Dissertations

STUDY 1: Role of endocytic regulator EHD1 and its binding partner RUSC2 in EGFR traffic

Abstract

Epidermal growth factor receptor (EGFR) is a prototype receptor tyrosine kinase and an oncoprotein in many solid tumors. Cell surface display of EGFR is essential for cellular responses to its ligands. While post activation endocytic trafficking of EGFR has been well elucidated, little is known about mechanisms of basal/pre-activation surface display of EGFR. Here, we identify a novel role of the endocytic regulator EHD1 and a potential EHD1 partner, RUSC2, in cell surface display of EGFR. EHD1 and RUSC2 colocalize with EGFR in vesicular/tubular …

Investigating A Novel Function For Phosphoserine Aminotransferase 1 (Psat1) In Epidermal Growth Factor Receptor (Egfr)-Mediated Lung Tumorigenesis., Rumeysa Biyik-Sit

Electronic Theses and Dissertations

Phosphoserine aminotransferase 1 (PSAT1) catalyzes the second enzymatic step within the serine synthetic pathway (SSP) and its expression is elevated in numerous human cancers, including non-small cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) mutant NSCLC is characterized by activating mutations within its tyrosine kinase domain and accounts for 17% of lung adenocarcinomas. Although elevated SSP activity has been observed in EGFR-mutant lung cancer cells, the involvement of PSAT1 in EGFR-mediated oncogenesis is still unclear. Here, we explore a putative non-canonical function for PSAT1 using biochemical approaches to elucidate unknown interacting proteins and genomic RNA-seq profiling to identify cellular …

The Biochemical Characterization Of Aza197 And A Ras Related Protein Cdc42, Alix Montoya-Beltran

Graduate Theses and Dissertations

Eukaryotic cells contain an extensive amount of GTP/GDP binding proteins. Proteins known as Ras GTPase primary function as a binary switch, where they cycle from an on and off state when GTP or GDP are bound, respectively. They are known to play a critical role in many cellular functions where a dysregulation could potentially lead to oncogenic behavior or other malignancies. In our laboratory, our focus is the study of a Ras related protein Cell division control 42 homolog (Cdc42) which belongs to the Rho subfamily. Cdc42 plays a critical role in many biological signaling processes; therefore, its uncontrol gene …

Investigations Into The Cellular Target Of 4-Trifluoromethoxy Chalcone Via Darts Method, Jordan Stacy

Undergraduate Theses

Cellular drug target discovery is an important step in any drugs journey from bench to bedside. This is true for our lab's molecule of interest, the Chalcone. The Chalcone molecule and its derivatives have been identified as small, plant-derived secondary metabolites that, when interacting with human cancer cell lines, trigger apoptotic pathways leading to varying levels of cell death. One derivative, 4-Trifluoromethoxy Chalcone (4TFM), was identified through screenings as inducing the highest death rate in A549 cancer cells, in conjunction with having the lowest IC50, making it a good candidate to use in searching for the currently unknown cellular target …

The Analysis Of Folate-Dependent Transcription Factor Zinc Finger Protein 410, Feifan Xu

Senior Honors Theses

A previous study that introduced dietary folate to mice in the form of folic acid to determine if gene activity would be altered based on this biological molecule demonstrated that mice without folic acid had cognition deficits, and this phenomenon was correlated with altered gene expression in their brains. The included bioinformatic analysis revealed two main transcription factors that bind to proteins in the nucleus, and one is known as the Zinc Finger Protein 410 (Zfp410). Due to the lack of literature explaining the function of this transcription factor, this project is intended to analyze Zfp410 in detail from scratch. …

216— Loss Of Function Mutation For Tp53 Does Not Rescue The Chaf1bNt2 Small-Eye Phenotype In Danio Rerio, Alex Parks

GREAT Day Posters

In Zebrafish, the chromosome assembly factor 1b (chaf1b) gene is in part responsible for the development of the eye. In homozygous chaf1bt24412 mutants retinal cell death is promoted through cell-death promoting activity of the gene, tumor suppressor protein p53 (tp53), resulting in a small-eye phenotype. Another allele chaf1bnt2, was found to also result in the small-eye phenotype when in a homozygous state. We found that knockdown of Tp53 protein via morpholino antisense oligonucleotide injection of 1-2 cell stage embryos failed to rescue retinal cell death of chaf1bnt2 homozygous mutants as detected by TUNEL labeling. Because morpholinos may fail to fully …