Cell and Developmental Biology Commons^™

The Genetic And Environmental Determinants Of Stress Resilience Across Model Systems, Carson Len Stacy

Graduate Theses and Dissertations

Survival in fluctuating environments demands that organisms effectively anticipate and respond to future challenges. This capacity is shaped by both genetic background and environmental context. In this dissertation, I apply a population aware lens to explore how genetic diversity and environmental conditions intersect to shape stress survival. Integrating functional genomics and transcriptomics in Saccharomyces cerevisiae (brewer’s yeast) and a vertebrate (common canary) system, I dissect gene-by-environment (GE) interactions that underpin resilience. First, I move beyond a single reference genome by using a pan-genomic CRISPR knockout screen to assess osmotic stress survival across diverse S. cerevisiae isolates. This analysis reveals a …

Bang!: Real-Time Measurements And Transcriptomics Of Metabolic Reprogramming In Activated Macrophages At Fever Temperature, Kenneth Howard Taylor

Graduate Theses and Dissertations

We investigated the real-time metabolic rates of activated macrophage cell lines derived from mouse, chicken and rainbow trout. Each species showed a different kinetic signature with metabolic rates accelerating under fever conditions specific to each organism. Upon activation mouse macrophages increased their rate of glycolysis early and then a later reprogramming phase occurred with a dramatic decrease in oxidative phosphorylation (OXPHOS) accompanied by a reciprocal second increase in glycolytic rates. Chicken macrophages showed an initial increase in both glycolytic and OXPHOS rates. The late drop OXPHOS rates also occurred in chicken however there was no reprogramming that occurred as glycolytic …

An Analysis Of Cellular And Tissue Function Of Lipin In Drosophila Melanogaster, Judah Christian Scott

Graduate Theses and Dissertations

Regulation of energy expenditure and energy storage is a key characteristic of life. Numerous enzymes play a crucial role in regulating energy metabolism. Lipins are a highly conserved family of proteins that function in both lipid synthesis and gene regulation. In the glycerol-3 phosphate pathway, lipins act as a phosphatidate phosphatase (PAP) producing diacylglycerol. In gene regulation, lipins act as transcriptional co-regulators of metabolic genes. The enzymatic PAP activity occurs in the cytoplasm; however, for lipins to function as gene regulators, they must translocate into the nucleus. Nuclear translocation is facilitated by the nuclear localization signal (NLS) within the protein. …

Bactericidal Mechanism Of Peracetic Acid Against Salmonella Mediated By Reactive Oxygen Species, Mohammed Khalid Wheib Al-Doury

Graduate Theses and Dissertations

Peracetic acid (PAA) is extensively used as a bactericidal agent in poultry processing to reduce foodborne pathogens, including Salmonella enterica serotype Typhimurium (S. Typhimurium). Despite its widespread application, the exact mechanisms underlying its bactericidal effects, particularly the role of reactive oxygen species (ROS), remain incompletely understood. This dissertation examines the role of ROS in PAA-mediated bacterial killing and explores both genetic and metabolic factors that influence bacterial susceptibility to PAA. Findings from these studies have implications for enhancing the efficacy of PAA, thereby improving food safety practices in the industry.

The first study investigates ROS as a central component …

The Expression Of Recombinant Cas9 Proteins In E. Coli Bl21(De3) Strains, Morgan Reese

Graduate Theses and Dissertations

Abstract Extensively used for genome editing, CRISPR-Cas9 is a relatively new tool that has made a major impact in the genomic engineering landscape. Due to this, the production of CRISPR proteins that are not commercially available can limit research applications. Here, we present methods for optimizing laboratory scale production of CRISPR proteins including Cas9. The method uses IPTG to induce gene expression of the specified Cas9 and nickel column purification to isolate proteins. CRISPR proteins are validated for purity by SDS-PAGE gel, western blot, and for activity by in vitro digestion. We thoroughly validate and compare the effectiveness of BL21(DE3) …

Amyloid Fibrils Of Human Fgf-1 Induced By Different Detergents, Zeina Ismael Ibrahem Alraawi

Graduate Theses and Dissertations

Nature achieves molecular self-assembly through the ordered growth of nanoscale building blocks with high efficiency to fabricate macromolecular architectures. One example of self- assembly is peptides folding onto protein is one of the most astounding biological self-assembly processes. When proteins aggregate to form amyloid fibers, the secondary structure of the protein converts from its native state to a cross-beta-sheet. Fibroblast growth factors (FGFs) possess an essential role in neuronal survival during development. In addition, they are involved in neural stem cell (NSC) proliferation. Fibroblast growth factors (FGFs) are well known to be synthesized in the central nervous system (CNS) and …

Characterization Of Human Fibroblast Growth Factor 2 Variant To Determine Effects On Structure, Stability, And Cell Proliferation, Ryan Layes

Graduate Theses and Dissertations

Fibroblast growth factors (FGFs) are a family of cell signaling proteins conserved across multiple species. Each individual FGF elicits different cellular functions including, but not limited to, proliferation, migration, differentiation, angiogenesis, and wound healing. One of the most studied members, fibroblast growth factor 2 (FGF2), has demonstrated substantial wound healing capacity in a wide range of tissues including skeletal, muscular, neural, respiratory, epithelial, and cardiovascular. This ability makes FGF2 a potential therapeutic for a wide range of conditions and injuries. However, due to a short half-life at room temperature, therapeutic use of FGF2 is limited. It has been demonstrated that …

Evaluating Mitochondrial Dynamics And Bioenergetics In Patient-Derived Human Induced Pluripotent Stem Cells And Differentiated Derivatives Modeling Leigh Syndrome, Fibi Meshrkey

Graduate Theses and Dissertations

Mitochondrial disorders are complex diseases that involve multiple systems and result from mutations and deletions in the mitochondrial genome. Leigh syndrome (LS) is a rare and devastating primary mitochondrial disorder characterized by progressive neuromuscular degeneration. Despite its severe consequences, the clinical genotype pathophysiological underlying LS remains elusive, posing significant challenges for the development of effective therapies. The current study aims to advance our understanding of the pathology and phenotype correlation of LS by evaluating mitochondrial dynamics and bioenergetics in patient-derived human induced pluripotent stem cells (hiPSCs) and their differentiated derivatives, which serve as a reliable model of the disease. Key …

The Roles Of Estrogen Receptor Alpha-Interacting Rnas And Exosomes In Breast Cancer, And E-Cadherin In Carcinomas, Brihget Catalina Sicairos-Meza

Graduate Theses and Dissertations

Carcinomas are malignancies of epithelial cells and account for >80% of cancer-related deaths. Approximately 75% of breast cancers express estrogen receptor alpha (ERα). ERα promotes breast cancer progression by enhancing cancer cell proliferation. Tamoxifen is commonly used to treat ERα-positive breast cancers but can result in endocrine therapy resistance. The mechanisms underlying endocrine therapy resistance remain elusive. The Du lab recently found that ERα is an RNA-binding protein. However, the significance of the ERα-RNA interaction is unknown. We fractionated ERα-positive MCF7 cells into cytoplasmic and nuclear fractions, followed by immunoprecipitation of ERα with associated RNAs and RNA-sequencing. We identified many …

Validation Of A Novel Genomic Biomarker Of Mesenchymal Stem Cell Scalability And Evaluating Genotype Implications On Cellular Senescence, I Kade Karisma Gita Ardana

Graduate Theses and Dissertations

The market demand for hMSCs continues to increase along with the increasing popularity of hMSCs used in the research, medical and industrial fields. This increase has an impact on the need for good quality MSCs. This quality is determined by the ability of MSCs to proliferate and their resistance to senescence. Donor dependent heterogeneity may affect MSC qualities from one individual to another; therefore, a specific biomarker with the ability to identify individuals with desirable hMSC qualities is required. The GSTT1 gene has been found to be associated with hMSC scalability. This gene is deleted in about 38% of the …

Investigation The Plugging Behavior Of Virus Filters, Iman Abdulqader Saab

Graduate Theses and Dissertations

A virus filtration step is integral to the manufacturing of biopharmaceuticals to ensure viral safety. A virus filter is a single-use device that uses a size-based separation process and has a unique structure with minimal defects, so that contaminating virus particles cannot pass through the membrane pores, while therapeutic molecules can. The development of novel antibodies (Abs), including significant increases in product titers, is frequently challenged by virus filter fouling, making a better understanding of the underlying mechanisms essential. This thesis focused investigating of the effect of prefilter types, buffer type and salt content on virus filtration performance. The impact …

Cell Division Dynamics Of Escherichia Coli In Extreme Environments, Steven P. Murray

Graduate Theses and Dissertations

Life is remarkable in how resilient it can be. Many organism, classified as ex- tremophiles, can not only survive in extreme environments, but they can thrive in them. In the search for extraterrestrial life, the best candidates to harbor life exist with some kind of extreme condition. Europa, for example, is a favorite for the possibility of accommodating life as we know it within our solar system. Thought there is believed to be a liquid ocean under its icy surface, this habitat would be under immense pressures and high salinity. To best know where to look for extraterrestrial life, it …

Differential Impacts Of Hhv-6a Versus Hhv-6b Infection In Differentiated Human Neural Stem Cells, Elham Bahramian

Graduate Theses and Dissertations

Within the family Herpesviridae, sub-family β-herpesvirinae, and genus Roseolovirus, there areonly three human herpesviruses that have been described: HHV-6A, HHV-6B, and HHV-7. Initially, HHV-6A and HHV-6B were considered as two variants of the same virus (i.e., HHV6). Despite high overall genetic sequence identity (~90%), HHV-6A and HHV-6B are now recognized as two distinct viruses. Sequence divergence (e.g., >30%) in key coding regions and significant differences in physiological and biochemical profiles (e.g., use of different receptors for viral entry) underscores the conclusion that HHV-6A and HHV-6B are distinct viruses of the β-herpesvirinae. Despite these viruses being implicated as causative agents in …

A Study On Interactions Between Metal-Organic Frameworks And Biological Materials, Josh Phipps

Graduate Theses and Dissertations

Metal-organic frameworks or MOFs are an extremely useful tool in many areas of applications. Their popularity in recent years has arisen from their high efficiency in catalytic chemical reactions. This is made possible due to their porous interior and the ability of the MOFs components to be functionalized. These same traits make MOFs excellent for use in protein encapsulation or immobilization and have the potential to become excellent drug carriers. Their development in this utilization has been limited dramatically compared to MOFs chemical applications. This is due in part to the nature of biological processes taking longer to study, but …

Hypothesis Testing And Parameter Estimation In Mixture Cure Models For Cancer Survival Data, Mohammod Mahmudur Rahman

Graduate Theses and Dissertations

In oncology clinical trials, when a treatment is administered to the patient population, a certain subset of patients may respond to the treatment while the other does not. The positive responders with long-term survival are considered “statistically cured” and can be referred to as cured patients or long-term survivors. When a proportion of patients achieve long-term survival, the hazard functions of two arms (control vs. treatment) are no longer proportional. As a result, the traditional log-rank test, which is the most popular test to evaluate the effectiveness of a treatment in clinical trials, tends to lose its power. In this …

Examining The Expression Patterns Of Desulfotalea Psychrophila Dsrab Operon And Pit At Subfreezing Temperatures And Different Concentrations Of Sulfate Salts As A Model For Mars And Icy Worlds Survival And Colonization, Sergio Luis Mosquera Mora

Graduate Theses and Dissertations

Since ancient times, Humanity has been fascinated with the idea of what lies beyond the borders of our planet. Fortunately, the combined efforts of many nations have made it possible to send unmanned spacecraft to orbit planets located close to Earth. These missions have the principal goal to collect data that could help us understand the basic environmental conditions that persist on those planets, or for evidence of past or present life. Equally important, landers and rovers have been successfully deployed to start the in-situ exploration of many planets of the Solar System. Among them, Mars has been extensively studied …

Sex Differences In Cancer Cachexia And A Novel Mitochondrial Target For Cancer-Induced Muscle Wasting, Seongkyun Lim

Graduate Theses and Dissertations

Cancer cachexia (CC) is a devastating wasting syndrome characterized by marked weight loss including skeletal muscle atrophy that affects approximately 80% of cancer patients. Current therapeutic treatments including pharmacological and nutritional intervention are insufficient to prevent or reverse it. Prior studies demonstrated lower muscle mass, impaired muscle function, and mitochondrial health in the development of CC. Specifically, mitochondrial fusion protein, Optic atrophy 1 (OPA1) which plays a significant role in skeletal muscle health, is suppressed in the development of CC. Furthermore, most pre-clinical CC studies were mainly focused on males although there are distinct phenotypical differences in skeletal muscle between …

The Effects Of Metronomic And Maximum-Tolerated Dose Chemotherapy In Colorectal Cancer Angiogenesis: A Combined Approach Using Endoscopic Diffuse Reflectance Spectroscopy And Mrna Expression, Ariel Isaac Mundo Ortiz

Graduate Theses and Dissertations

Colorectal cancer (CRC) continues to be one of the most incident and deadliest types of cancer worldwide. Chemotherapy has proven effective to reduce tumor burden for CRC patients, but there are several disadvantages associated with the use of mainstay maximtolerated dose (MTD) chemotherapeutic strategies. Metronomic chemotherapy (MET) has been developed as an alternative that addresses the shortcomings of maximum-tolerated dose chemotherapy but so far its effectiveness as a neoadjuvant strategy for CRC has not been explored.

This dissertation uses a combined optics and molecular biology approach (using diffuse reflectance spectroscopy and mRNA expression) to study the changes in angiogenesis and …

Characterization Of The Influence Of A Small Molecule Inhibitor On Ras-Related Proteins Interactions, Emilio Duverna

Graduate Theses and Dissertations

The Ras superfamily of small G proteins are involved in cell-signaling processes that, if not regulated, may lead to cell multiplication, apoptosis inhibition, and tumorigenesis. They function as molecular switches, which through GTP/GDP exchange cycle, switch on or off cellular activities. Overexpression and/or hyperactivity of these proteins have been linked to many diseases including various cancers. CDC42, a member of the Rho subfamily of the Ras superfamily of small G proteins, participates in the regulation of many cellular processes including cell adhesion, mitosis, and cytoskeletal rearrangements. CDC42 binds to and activates many effector proteins including CDC42-activated kinase (ACK). Abnormal activities …

Development Of A Long-Read Sequencing Protocol To Assess The Precision And Efficacy Of Gene Editing For Duchenne Muscular Dystrophy, Landon Andrew Burcham

Graduate Theses and Dissertations

This work establishes a method for assessing on-target precision due to CRISPR-Cas9 gene editing, especially within the context of exon skipping therapy for Duchenne Muscular Dystrophy. The proposed method utilizes an Oxford nanopore long-read sequencing approach to sequence amplified regions of DNA that have been edited using CRISPR-Cas9. NIH3T3 and C2C12 cell lines were treated with a dual-guide CRISPR-Cas9 system, that targets and deletes exon 23 from the DMD gene in mouse samples. Deletion PCR revealed deletion of exon 23 in both DNA and cDNA samples. Additionally, sequencing using Oxford Nanopore revealed targeted exon 23 deletion as the most prevalent …

Preparation Of Proteins And Peptides From Heat-Stabilized Defatted Rice Bran Via Solid State Fermentation And Investigating For Skin Health, Ali A. Bisly

Graduate Theses and Dissertations

Heat-stabilized defatted rice bran (HDRB) is an abundant and inexpensive agro-industrial by-product of rice milling and rice oil extraction process. Furthermore, HDRB is a potential source of proteins. However, the direct protein extraction has low yield of protein due to the impact of heat stabilization and oil extraction process which made the HDRB proteins bound and interact with other components. This research is based on using solid-state fermentation (SSF), which is a natural and cost-effective approach to facilitate protein extraction from HDRB using Bacillus subtilis (natto) Takahashi as a microorganism.

Response surface methodology (RSM) analysis was used with Box-Behnken design …

Growth Differentiation Factor 5 Is A Paracrine Regulator Of Sarcopenic Obesity, Landen W. Saling

Graduate Theses and Dissertations

Sarcopenic obesity attributes to skeletal muscle loss more than sarcopenia and obesity alone. Individuals with SO suffer from the comorbidity of excess body fat and concurrent muscle mass loss due to aging. Growth differentiation factors (Gdfs) have never been recognized as playing a role in skeletal muscle maintenance in those with SO. Specifically, Gdf5, has been recognized as playing a part in Bone Morphogenic Protein signaling to activate protein synthesis and deactivate protein degradation via SMAD 1/5/8 and SMAD 4 complex. Using RNA sequencing, Gdf5 was identified as being significantly upregulated in SO mice. Purpose: To determine the cellular role …

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 …

Longitudinal Monitoring Of Tumor Response To Immune Checkpoint Inhibitors Using Diffuse Optical Spectroscopy, Joel Isaac Rodriguez Troncoso

Graduate Theses and Dissertations

Immune checkpoint drugs have completely changed the way people treat metastatic melanoma and non-small-cell lung cancer. While the impacts of these immunological checkpoints and their suppression on T cell function are well characterized, their consequences on the tumor microenvironment are not. In a CT26 mouse colorectal cancer model, we employed diffuse reflectance spectroscopy to track in vivo tumor microenvironmental alterations in response to immune checkpoint inhibitors. On three separate days, animals bearing CT26 tumor xenografts were given anti-PD-L1, anti-CTLA-4, a combination of both inhibitors, and isotype control. Within the first 6 days, monotherapy with either anti-PD-L1 or anti-CTLA-4 resulted in …

Role Of Sex Differences On Cancer Cachexia Progression And Fibrosis During Cancer Cachexia Development, Wesley Haynie

Graduate Theses and Dissertations

Cancer cachexia is a multifactorial wasting syndrome characterized by losses in bodymass >5% and occurs in approximately 80% of all cancer patients. Chronic inflammation and fibrosis play roles in cancer cachexia and a greater understanding of these contributing pathways to this pathology will pave the way for potential therapeutic avenues. While inflammation and fibrosis have been researched in various models of cancer cachexia, little to no studies have been performed in both sexes as most previous studies focus on males. PURPOSE The purpose of these studies is to investigate the role of fibrosis on cancer cachexia development as well as …

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. …

Directed Genome Evolution To Identify Genes For Macrophage Survival By Staphylococcus Agnetis, Sonali Lakshika Anne Lenaduwe Lokuge

Graduate Theses and Dissertations

Bacterial Chondronecrosis with Osteomyelitis (BCO) is a debilitating infection that negatively impacts animal welfare and costs the broiler industry billions of dollars annually. We have previously isolated Staphylococcus agnetis 908 from BCO samples obtained from broilers at the University of Arkansas research farm. This isolate can induce BCO lameness at greater than 50% in broilers exposed to the pathogen in drinking water. We found that S. agnetis 908 is capable of surviving and escaping macrophages compared to a closely related cattle isolate,1379. Through Directed Genome Evolution (DGE) we identified that this difference is at least partially associated with an alanine …

Host-Parasite Interactions Within Food Webs, Adam Zvanut Hasik

Graduate Theses and Dissertations

Parasitism is one of the most common life history strategies employed in nature, yet the effects of parasites are often thought to be minimal, and the vast majority of studies fail to consider parasites and their effects on host organisms. This is likely a problem, as the magnitude of parasite-mediated effects on their hosts can be quite large. Additionally, the effects of parasites are known to extend beyond the host to affect other species interactions. I used a series of approaches to gain a more integral understanding of host-parasite interactions by studying (1) the effects of parasites on biotic interactions …

Characterization Of Iron-Sulfur Cluster Biogenesis In Methanogenic Archaea, Thomas Modlin Deere

Graduate Theses and Dissertations

Iron-sulfur (Fe-S) clusters are among the oldest cofactors on the planet, used by proteins in almost all forms of life on Earth to carry out processes ranging from energy transfer to DNA replication. Among the organisms believed to use these Fe-S proteins more extensively than almost any others are the methanogens, an ancient lineage of archaeal microbes that produce methane as a required product of their metabolism. Methane, the primary component of commercial natural gas, is both a potent greenhouse gas and an important fossil fuel. It can also be renewably produced as a biofuel. Biogenic methane is almost entirely …

The Characterization Of Angiopoietin-Like Protein 4 Overexpression In Triple Negative Breast Cancer, Jodi Simeon

Graduate Theses and Dissertations

Triple Negative Breast Cancer (TNBC) is highly invasive and metastatic with approximately 15% of patients developing liver metastases. The primary treatment of metastatic TNBC is chemotherapy, however, there is an increased chance of resistance to this therapeutic technique. If Breast Cancer Liver Metastasis (BCLM) is left untreated most patients survive only 4 to 8 months with a very rare 5-year survival. Therefore, it is imperative to analyze markers and molecular pathways that TNBC cells use to progress, invade, and metastasize to the liver. The aim of this study was to examine the overexpression of angiopoietin-like 4 (ANGPTL4) in TNBC cells …