Cell and Developmental Biology Commons^™

A Computational Micropatterning Approach To Study Caveolae And Protein Localization In Vascular Biology, Andrew B. Grespin

Electronic Theses and Dissertations

Caveolae are specialized, flask-shaped membrane invaginations highly expressed in endothelium and dysregulated in atherosclerosis. Caveolae play a central role in buffering membrane tension, yet the principles governing their spatial organization remain elusive. Thus, we sought to generate the most comprehensive and systematic analysis of blood vessel caveolar spatial organization. However, cell culturing, the backbone of human-focused biological research, does not standardly do well to model physiologically relevant cell behaviors such as migration or polarity-based tissue formation, particularly for punctate proteins and structures like caveolae. Micropatterns are cell-adhesive shapes that biophysically confine cell(s) to a user defined geometry which stereotype organelle …

Contribution Of G4 Structure To Alzheimer’S Disease And Tau Pathology, Lena Michaela Kallweit

Electronic Theses and Dissertations

The occurrence of Alzheimer’s Disease (AD) is rapidly increasing as our global population ages. With the majority of therapeutic drugs in the last couple of decades failing clinical trials, new molecular targets are needed to combat the expected influx of new AD cases. AD pathogenesis is associated with abnormal protein aggregation, characterized in part by intracellular accumulation of hyperphosphorylated tau (p-tau) in neurofibrillary tangles (NFTs). RNA has been identified as a major non-proteinaceous component of NFTs and has been implicated as an active cofactor in tau aggregation and spread. Recent work has shown that aggregates from AD brains contain almost …

Characterizing The Ethanol Sensitivity Of The Planar Cell Polarity Pathway In Endoderm Morphogenesis And Jaw Development., Raéden Omneil C. C. Rolle Gray

Electronic Theses and Dissertations

Fetal Alcohol Spectrum Disorders (FASD) describes a large range of developmental defects due to prenatal alcohol exposure. It is characterized by neural and facial defects, including jaw hypoplasia. Many factors contribute to the susceptibility of ethanol-induced facial defects, including genetics, yet the genes involved, and the cell events they regulate, are poorly understood. Zebrafish have a large number of tools for genetic manipulation available, share 70% of genes with humans, are fertilized externally and are translucent during embryogenesis, making them great models to study FASD. Previous studies show that two members of the Planar Cell Polarity (PCP) pathway, zebrafish vangl2 …

A Persistent Homology Framework For Scrna-Seq: Assessing Clustering Robustness And Quantifying Preprocessing And Integration Effects On Topological Features., Jonah Daneshmand

Electronic Theses and Dissertations

As single-cell RNA sequencing (scRNA-seq) data expands, robust methods for integrating diverse datasets are critical. This dissertation applies Persistent Homology (PH), a technique from Topological Data Analysis (TDA), to a collection of scRNA-seq datasets spanning eight tissue types to quantify how data integration affects topological features and biological interpretability. We assessed global topological structure using Betti curves, Euler characteristics, and persistence landscapes across raw, normalized, and integrated data representations. Our analysis revealed a performance inversion: while conventional methods excelled on unintegrated data, high-granularity topological methods, particularly those sensitive to global data structure, became superior after integration. This suggests a synergy …

A Ralgef Inhibitor Suppresses Lung Cancer Stem Cell Development And Tumorigenesis., Raphael Ngozichi Suarez Jigo

Electronic Theses and Dissertations

The RALGEF family of proteins are direct downstream effectors of the RAS oncoprotein. RALGEFs act as guanine nucleotide exchange factors (GEFs) for downstream RAL proteins, thus tying RAS to the regulation of RAL. Genetic studies have demonstrated RAL proteins to be key drivers of RAS-driven transformation and metastasis. Furthermore, this pathway has been implicated in chemoresistance, exocyst-mediated transport, and the modulation of cancer stem cells. Previous work in our lab reported the activity of a novel pan-RALGEF inhibitor (C4-180) against RAS-driven pancreatic cancer models. Here we show the agent to be active against in vitro and in vivo models of …

Further Characterization Of The Fungal Effector Mvlg-01732 In Planta And Heterologous Expression Of Fungal Effectors In Different Smut Fungi., Joseph Paul Ham

Electronic Theses and Dissertations

Host-pathogen interactions in smut fungi are characterized by effector proteins and their role in infection. The goal of this work is to better understand these interactions by further characterizing an effector from Microbotryum lychnidis-dioicae and heterologously expressing this and other effectors in heterologous species to see if the range of these effectors can play a role in pathogenicity when expressed in distantly and closely related fungal species. These effectors have been attuned over time to their host plant but have homologous interactors in other plant species. In this study, Microbotryum lychnidis-dioicae, Sporisorium reilianum, and Ustilago maydis, were all used …

Centrosomal And Non-Centrosomal Microtubule Networks Coordinate To Drive Nuclear Dynamics In Developing Epithelium, Rashmi Budhathoki

Electronic Theses and Dissertations

The morphogenesis of developing tissues relies on extensive cellular rearrangements in shape, position, and identity. A key process in reshaping tissues is cell intercalation-driven elongation, where epithelial cells align and intercalate along a common axis. Typically, analyses focus on how peripheral cortical forces influence cell shape changes. Less attention is given to how inhomogeneities in internal structures, particularly the nucleus, impact cell shaping. Here, we examine how pulsed contractile and extension dynamics interact with the nucleus in elongating Drosophila embryos. Our data show that tightly packed nuclei in apical layers hinder tissue remodeling/oscillatory behaviors. We identify two mechanisms for resolving …

Analysis Of An Ethanol Sensitive Bmp-Nkx2.3-Fgf Signaling Pathway In Pouch Morphogenesis., Hieu Dai Le Vo

Electronic Theses and Dissertations

Craniofacial malformations lie at the heart of Fetal Alcohol Spectrum Disorders (FASD). While there is growing evidence for a genetic component to FASD, little is known of the cellular mechanisms underlying these ethanol-sensitive loci in facial development. Bone Morphogenetic Protein (Bmp) signaling pathway dependent pouch formation is a key mechanism in facial development. We have previously shown that multiple Bmp mutants are sensitized to ethanol-induced facial defects. However, ethanol does not directly impact Bmp signaling. This suggests that downstream effectors, like nkx2.3 and Fibroblast Growth Factor (Fgf) signaling, may mediate the impact of ethanol on Bmp mutants. Here, I …

Metabolic Regulation Of Cardiac Fibroblast Phenotype And Function., Collin Kleis Wells

Electronic Theses and Dissertations

Cardiac fibroblasts are central effectors of cardiac repair after myocardial infarction (MI). In response to signaling cues, they differentiate to a range of phenotypes with robust capacities to synthesize and secrete extracellular matrix (ECM) and signaling molecules. Although activated fibroblast phenotypes are associated with pronounced changes in metabolism, it remains unclear how the metabolic network upholds the effector functions of fibroblasts in the post-infarcted heart. Here, we identified that critical enzymes in the phosphoenolpyruvate (PEP) cycle, i.e. pyruvate kinase muscle-2 (PKM2) and phosphoenolpyruvate carboxykinase-2 (PCK2), are elevated in the heart after MI and examined their role in regulating post-MI remodeling …

A Toi Rna Editing In Three Members Of The Microbotryum Violaceum Fungal Complext And Characterization Of Adar Genes Of Microbotryum Superbum., Shikhi Baruri

Electronic Theses and Dissertations

A-to-I RNA editing is a process that occurs post-transcriptionally. Through this process, adenosine (A) is replaced by inosine (I) in RNAs by adenosine deaminase enzymes that act on the single-stranded RNA. These enzymes, also known as ADARs, act on RNA. The translation and splicing mechanisms subsequently interpret inosine as guanosine (G), which effectively alters genetic information. This kind of RNA alteration can cause both nonsynonymous and synonymous changes in codon, which may have an impact on protein function. A group of over 89 basidiomycete fungal species known as the Microbotryum violaceum complex infects a similarly large group of plant host …

Carbon Monoxide Releasing Polymeric Micelles, Riya Joshi

Electronic Theses and Dissertations

Carbon monoxide (CO), traditionally known as a toxic gas, has emerged as a potential therapeutic agent due to its cytoprotective, anti-inflammatory, and vasodilatory properties. This study explores the development of CO-releasing polymeric micelles as a controlled delivery system for biomedical applications. Using ring-opening metathesis polymerization (ROMP), we synthesized diblock copolymers incorporating CO-releasing moiety diphenylcyclopropenone (DPCP) with hydrophilic polyethylene glycol (PEG) to enhance solubility and stability of the overall CO releasing system. Dynamic light scattering (DLS) and electron microscopy (EM) confirmed the formation of well-defined micelles, while fluorescence assays demonstrated efficient CO release with the use of Iridium photocatalyst under 470 …

Investigating The Effect Of Fasting On Senescent Cells In Nothobranchius Furzeri Fish, Israel A. Akinola

Electronic Theses and Dissertations

Senescent cells (SCs) have been documented to accumulate with age in the organism. Recent studies have shown that reducing the number of SCs in an organism result in tissue rejuvenation and extension of life expectancy. Intermittent fasting is reported to have multiple health benefits and is speculated to reduce the burden of SCs. Nothobranchius furzeri are a new model organism for studying aging and for which there are short- and long-lived strains available. We hypothesize that long- and short-lived strains of N. furzeri will accumulate SCs at different rates; and that fasting will reduce the burden of SCs.

The results …

Translation Of The Carcinogenic Dna Breakage-Repair Inhibition Mechanism For Hexavalent Chromium To Its Key Targets: Lung Epithelial Cells, Lung Tissue And Impacts On The Genome., Idoia Meaza Isusi

Electronic Theses and Dissertations

Lung cancer is the leading cause of cancer death worldwide. Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread occupational and environmental exposure. Despite the known health risks, how Cr(VI) causes lung cancer remains unclear. This dissertation investigates the mechanisms of Cr(VI)-induced carcinogenesis. Cr(VI) causes DNA damage, specifically DNA double strand breaks, and inhibits homologous recombination repair, a high-fidelity repair pathway. Unrepaired DNA double strand breaks or those repaired through error-prone pathways, progress to chromosomal damage, and chromosome instability. The latter is a common characteristic of Cr(VI)-exposed cells, and a hallmark of lung cancer. Although the mechanism of Cr(VI)-induced …

Differential Responses Of Human Neutrophils To Legionella Species., Hannah E. Hanford

Electronic Theses and Dissertations

Legionella species are Gram-negative facultative intracellular bacterial pathogens commonly found in freshwater or soil environments where they survive and replicate within their natural protozoan hosts. Humans serve as an accidental host for Legionella species after inhalation of contaminated aerosolized water droplets or soil particles enabling the bacteria to enter the lungs, infect alveolar macrophages, and result in severe pneumonia. Evasion of degradation and proliferation within alveolar macrophages by Legionella species and manifestation of “Legionnaires’ disease” is dependent on the Dot/Icm type IV secretion system (T4SS). The T4SS apparatus is a needle-like channel for translocation of over ~350 effector proteins, depending …

Dysfunction Of Polyamine Metabolism In Down Syndrome Related To Cellular Senescence And Β-Amyloid Production, Andres D. Sola

Electronic Theses and Dissertations

Polyamines (PA) are ubiquitous in cells and highly involved in several important cellular functions and thus the dysregulation of their biosynthetic pathway is potentially associated with the progression of age-related diseases like Alzheimer’s’ disease (AD). Though there is research describing how PA content changes in organisms as they age or in those experiencing rapid aging from increased rates of senescence, as in Down syndrome (DS), it is not clear how this connection occurs and whether modulating this pathway may reveal downstream effects on related disease progression. This study examines how the modulation of the PA biosynthetic pathway by inhibition of …

Unraveling The Role Of Hid-1: Insights Into Sgii Regulation, Breanna L. Sellers

Electronic Theses and Dissertations

The regulated secretory pathway is important for the secretion of hormones and neuropeptides from large dense core vesicles (LDCVs). Dysregulation of the biogenesis of LDCVs can result in metabolic and neurological diseases. Recent studies have suggested that the peripheral membrane protein HID-1 plays a role in the sorting and storage of granins which contribute to LDCV biogenesis. To further understand how HID-1 influences the regulation of granins, we investigated potential HID-1 interactors. We determined that while HID-1 is likely functioning in the same pathway as USP25, a deubiquitinating enzyme (DUB), the cause of reduced cellular SgII levels is likely not …

Manipulation Of Cellular Proliferating Cell Nuclear Antigen (Pcna) During Herpes Simplex Virus Type 1 Infection, Jessica Packard, Jill A. Dembowski

Electronic Theses and Dissertations

Herpes simplex virus type 1 (HSV-1) is a double stranded DNA virus that replicates within the nucleus of host cells. Using accelerated native isolation of proteins on nascent DNA (aniPOND), cellular proteins were found to associate with HSV-1 replication forks. One host factor of interest is proliferating cell nuclear antigen (PCNA), the DNA sliding clamp that tethers DNA polymerases and DNA damage response proteins to replicating cellular DNA. Although HSV-1 encodes its own DNA polymerase processivity factor (UL42), PCNA plays a key role in HSV-1 infection. We used commercially available PCNA inhibitors and short hairpin RNAs (shRNA) to investigate how …

The Role Of Edc3 In Drosophila Melanogaster Neuronal Development, Keelan Zius

Electronic Theses and Dissertations

Enhancer of mRNA-decay 3 (Edc3) is a component of multiple decapping complexes that regulates the transcriptome by targeting a subset of transcripts for decapping for 5’-to-3’ messenger RNA (mRNA) decay. A missense mutation in the conserved Lsm domain of Edc3 has been reported in two siblings presenting with mild, non-syndromic intellectual disability (ID), however, the role of Edc3 is neuronal development has never been evaluated. Here, we use the Drosophila melanogaster model system to investigate the effects of Edc3 disruption on neuronal development. We found Edc3 reduction leads to significant hyperplasia at the larval neuromuscular junction (NMJ), providing the first …

Neuroinflammation In Alzheimer’S Disease Mouse Brain Following Repetitive Mild Traumatic Brain Injury, Lujain Almuhanna

Electronic Theses and Dissertations

Traumatic brain injuries (TBIs) are a common form of head injury, with mild TBIs (mTBIs) making up 75-90% of the TBI severity scale. It’s been suggested that repetitive mild TBIs (rmTBIs) may enhance effects of Alzheimer’s Disease (AD). With dementia linking TBI and AD together, we investigated the memory hub of the brain - the hippocampus. Astrocytes and microglia are two glial cells that respond to neuroinflammation and therefore imaged in hippocampal regions of the 3xTg-AD mouse brain. We hypothesized that AD brain pathology (i.e., neuroinflammation) would be accelerated in 3xTg-AD mice following rmTBIs early in life. Analyses revealed that …

Characterization Of Oxidized Tau Protein Aggregation And Inhibition Of Tau Aggregation Via Map2, Brad Krzesinski

Electronic Theses and Dissertations

Neurofibrillary tangles (NFT) composed of the microtubule stabilizing protein Tau are a pathological hallmark of Alzheimer's disease (AD) and many other dementia related diseases specified as Tauopathies. Due to alternative mRNA splicing, intrinsically disordered Tau exists as six separate isoforms in the adult human brain where they are categorized by the lack or inclusion of the second repeat in the microtubule binding domain (3R or 4R respectively). Isoforms are subcategorized by the inclusion or lack thereof, one or two N-terminal inserts. Many studies show that Tau aggregates into amyloid fibrils and these fibrils can break into small oligomeric units known …

Morphological Remodeling Of The Endoplasmic Reticulum During Mitosis And Its Influence On The Integrity Of The Spindle Apparatus, Katie R. Rollins

Electronic Theses and Dissertations

The Endoplasmic Reticulum (ER) is the largest organelle in the cell by surface area and forms contacts with other organelles throughout the cell. In recent work, the ER has been implicated in numerous processes within the cell beyond its canonical roles of protein synthesis and calcium storage. The ER also undergoes a remarkable transition in morphology during cell division, with mitotic divisions requiring a massive remodeling of various membranous organelles such as the nuclear envelope and Golgi. However, whether changes in ER behaviors modulate mitotic events is less clear. The rapid cleavage divisions in the early Drosophila embryo are a …

Omani Camels From A Cultural And Genomics Perspective, Al Muatasim Al Zadjali

Electronic Theses and Dissertations

The Dromedarian camel, Camelus dromedarius, is native to the Arabian Peninsula, including the Sultanate of Oman. These camels are used for food, milk, as well as show and racing competitions. Despite their economic and cultural importance research on camels in Oman is limited. The goal of this study was to examine their genomic variation, relationship with camels in other parts of the Arabian Peninsula, and to determine if selective breeding has led to the establishment of distinct breeds in Oman. Information was compiled from multiple sources to produce a comprehensive review on the breeding, management, economic and cultural use, …

Investigating The Role And Mechanism Of Host Cell Death In Porcine Reproductive And Respiratory Virus Infection, Michelle Steyn

Electronic Theses and Dissertations

No abstract provided.

Elucidating The Role Of Sialic Acid In Tumorigenic Pathways, Kakali Das

Electronic Theses and Dissertations

Hypersialylation is a prognostic biomarker in cancer cells. The upregulated sialic acid expression on cancer cells facilitates tumorigenesis by playing a critical role in cancer cell proliferation and growth, immune evasion, cell signaling, and metastasis by interacting with various carbohydrate-binding molecules. Sialic acids on cancer cell surface undergo various modifications like O-acetylation at positions 4,7,9 de-acetylation and addition of glycolyl group at position 5. In our first chapter we analyzed the effect of de-acetylated sialic acid on migration via selectin binding in colon cancer cell line HCT116 and in lung cancer cell line A549. Selectins are calcium-dependent cell adhesion molecules …

Air-Jet Bioprinting Of Stem Cell-Encapsulated Alginate Micro-Droplets For Organoid Biomanufacturing, Mirabella B. Stump

Electronic Theses and Dissertations

Biomanufactured 3D-organoids show promise for modeling and treating various conditions, particularly insulin-dependent diabetes mellitus (type-1 diabetes). Pancreatic islet organoids serve as sustainable sources of insulin-producing β-cells, potentially restoring insulin regulation in patients and providing a long-term solution for diabetes. Hydrogel droplet printing is an emerging technique in regenerative medicine due to its advantageous tunability and biocompatibility; however, challenges of consistency, quality control, and scalability persist. To address these issues, we developed a novel air-jetting based droplet bioprinting system for the generation of monodispersed alginate micro-droplets. The objective of this project was to incorporate human induced pluripotent stem cells (hiPSCs) into …

Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil

Electronic Theses and Dissertations

Understanding how innocuous organisms can evolve to be pathogenic to humans is of increasing global concern. Further, understanding how existing pathogens may evolved to be more virulent is also vital to our ability to provide healthcare to people afflicted with diseases that promote chronic bacterial infections, such as cystic fibrosis. With the rise of antibiotic resistance in both bacteria and fungi it is paramount that new therapeutics are identified. Understanding what mutations occur that result in increased virulence in microbes can potentially provide new targets for antimicrobial drugs to combat antibiotic resistance. The Coincidental Evolution Hypothesis is a fundamental hypothesis …

Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke

Electronic Theses and Dissertations

The number of daily bacterial infections is climbing and the CDC explains that this is due to the antibiotic-resistant threat in the United States. Finding a faster way of bacterial identification is necessary as it currently takes 1-4 days for a medical lab to culture and identify bacteria. Photoacoustic flow cytometry (PAFC) can be used as an alternative method resulting in swift identification within an hour (Edgar, 2019). Pseudomonas aeruginosa, cell line PA01, will be coated in up to a few hundred red dyed phages making it detectible by the photoacoustic flow cytometry system. Bacteriophages (phages) are viruses that …

Spatial Structure Formation By The Post-Transcriptional Gene Regulator Rsme In Pseudomonas Fluorescens Pf0-1, Anton Evans

Electronic Theses and Dissertations

Microorganisms are often found in microbial communities we call biofilms. Organisms living in these crowded environments have significant evolutionary pressure to retain access to the resources necessary to sustain life. My research uses the bacterium Pseudomonas fluorescens Pf0-1 to study how organisms evolve strategies to solve this crowding problem as aging colonies repeatedly generate mutant patches. These mutants expand the reach of the colony resulting in decreased local density as they push themselves up to the resource rich surface. These spatial structures result from social interactions between the mutant and the parental cells mediated through extracellular secretions, resulting in the …

Multiphasic Molecular Mechanisms Regulate Expression Of Interleukin 1Β, As Well As Other Immediate-Early Genes, In Monocytes And Macrophages, David Macar

Electronic Theses and Dissertations

Interleukin 1β (IL-1β), an important cytokine in both health and disease, functions as a major proinflammatory mediator of pathological challenges, including involvement in the cytokine storm associated with Macrophage Activation Syndrome, Hemophagocytic Lymphohistiocytosis and the severe secondary effects of SARS-CoV-2 infection. Therapeutic approaches to limiting the effects of IL-1β protein have focused either on specific protein neutralization before release from activated macrophages (by general metabolic inhibitors and inflammasome inhibition) or after release by ligand and receptor obstruction (e.g., Canakinumab, Anakinra and Rilonacept). Although these approaches are efficacious, they inhibit steps after gene expression. Since a single gene expresses …

Polar Body Membrane Breakdown Occurs Independent Of Macroautophagy In C. Elegans, Shruti Kolli

Electronic Theses and Dissertations

Failure to digest cell corpses can lead to lupus-like autoimmune disorders in mammals. To better understand if LC3-associated phagocytosis (LAP) drives cell corpse breakdown in phagolysosomes, we studied the clearance of the C. elegans polar body during embryonic development. ATG16L1 has separable roles in regulating LC3 recruitment during macroautophagy and LAP. We demonstrated that the ATG16L1 C. elegans orthologs, ATG-16.1 and ATG-16.2, function redundantly to promote polar body membrane breakdown. We also discovered that truncating the LAP-specific WD40 domain of ATG-16.2 unexpectedly disrupts autophagy. Furthermore, we confirmed that polar body membrane breakdown occurs independent of macroautophagy. We also showed that …