Molecular Biology Commons^™

Caspases Protect Against Hyperglycemia Induced Necroptosis-Like Cell Death In Brain Endothelial Cells, Aleena S. Mathew

Theses and Dissertations

Acute diabetes characterized by high spikes in blood glucose levels in association with severe hyperglycemia can lead to an increased risk of ischemic stroke in the brain. To better understand high blood glucose levels, hyperglycemia, in the brain we explored its effects on endothelial cells. Endothelial cells line the inner walls of blood vessels and are directly impacted in hyperglycemia. Brain endothelial cells are a major component of the blood brain barrier (BBB) which tightly regulates the brain’s microenvironment. The type of cell death such as apoptosis, caspase dependent, or necroptosis, caspase independent, can exacerbate diabetes associated complications. There is …

Investigating Mono-Driver Versus Multi-Driver Oncogenesis Via Alterations To Cell Signaling Pathways, Abygail Chapdelaine

Open Access Dissertations

The latest edition of Global Cancer Statistics released by the American Cancer Society reported approximately 20 million newly diagnosed cancer cases worldwide in 2022 with 9.7 million deaths. This ranks cancer as the second leading cause of death worldwide. For the majority of cancer patients, the standard treatment approach is chemotherapy and/or radiation therapy, and while this has been successful in some patients, a lack of specificity to cancer cells causes severe side-effects when these agents damage healthy cells. Despite extensive efforts that have gone into developing targeted cancer therapeutics that block functions specific to cancer, they have not been …

Using Lateral Flow Assay To Assess The Prevalence Of Trachemys Hybridization, Lillian Groves

Honors Program Theses

The current study focuses on Trachemys species, which is a group of freshwater turtles found throughout the Greater Antilles. The role of studying an isolated island, such as the Dominican Republic, is significant because it serves as a way to better understand how the combined effects of species migration, mass tourism, and climate change can greatly impact isolated species. Of particular significance is how these forces interact in complex ways to reshape habitats and threaten biodiversity. Additionally, the introduction of a highly invasive species, Trachemys scripta elegans (T. scripta), in this environment pressures native species by acting as a source …

P23h Rhodopsin Accumulation Disrupts Synaptic Protein Levels In Rod Photoreceptors, Samantha Thompson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rod photoreceptors are specialized neurons located in the retina, the neural tissue that lines the back of the eye. Rod photoreceptors are necessary for dim light and peripheral vision through the photoactivation rhodopsin (Rho). Rho is synthesized in the inner segment of rods before being unidirectionally trafficked to the outer segment. In diseases such as retinitis pigmentosa (RP), Rho trafficking can be disrupted, leading to progressive rod cell death. In many cases of RP, Rho is mislocalized to the rod photoreceptor synapse (“spherule”). The impact of Rho mislocalization on spherule structure and protein organization is poorly understood. We hypothesize that …

Probing The 10-23 Dnazyme Catalytic Core: Insights From Structural And Mechanistic Studies, Evan Rhyse Cramer

Graduate Theses, Dissertations, and Problem Reports (ETD)

The 10-23 DNAzyme is a catalytically active DNA oligonucleotide capable of cleaving RNA at purine-pyrimidine junctions in the presence of divalent metal ions, most notably magnesium. Despite its promise as a programmable RNA knockdown tool, its clinical and biotechnical utility has been hampered by limited structural characterization, low catalytic efficiency under physiological conditions, and poor understanding of its in-cell activity. This dissertation presents a comprehensive framework for the structural and functional analysis of DNAzymes using the 10-23 DNAzyme as a model system. In the absence of high-resolution structures, we first employed detailed in vitro biochemical assays to map essential residues …

The Role Of Fruiting Bodies In Protecting A Community Of Myxococcus Xanthus Spores From The Environment, Dave Lall

Wayne State University Dissertations

Environmental microorganisms have evolved a variety of strategies to survive fluctuations in environmental conditions, including the production of biofilms and differentiation into spores. Myxococcus xanthus are ubiquitous soil bacteria that produce starvation-induced multicellular fruiting bodies filled with environmentally resistant spores (a specialized biofilm). Isolated spores have been shown to be more resistant than vegetative cells to heat, ultraviolet radiation, and desiccation. The evolutionary advantage of producing spores inside of fruiting bodies is not clear. Here, we examine a hypothesis that the fruiting body provides additional protection from environmental insults. We developed a high-throughput method to compare the recovery (outgrowth) of …

Examining The Biotic And Abiotic Degradation Of Simple Phenols, Madeline Gruenberg

Browse all Theses and Dissertations

Plant secondary metabolites are a diverse class of compounds that encompass small phenols to large polymeric structures such as tannins. Smaller compounds such as phenolic acids can serve as substrates for soil microbes and enzymes. We monitored the degradation of three small phenols pyrogallol, gallic acid, and benzoic acid in biotic and abiotic conditions. They were chosen to observe the impacts of specific functional groups on both degradation processes and act as model compounds to mimic larger tannin reactivity. Both abiotic and biotic degradation of pyrogallol resulted in the formation of a stable quinone, while abiotic degradation of gallic acid …

The Role Of Fbxl16 In Regulating Erk3 Stability And Cell Migration, Seth Charles Murdock

Browse all Theses and Dissertations

Extracellular signal-regulated kinase 3 (ERK3) is a member of the atypical mitogen-activated protein kinase (MAPK) family. While ERK3’s role in promoting cell migration and invasion in multiple types of cancer has been well-documented, its activation and regulation remain poorly understood. Unlike other typical MAPK proteins, whose activation is regulated via the phosphorylation of an upstream kinase, ERK3 is regulated through its abundance, as it is constitutively phosphorylated when present in the cell. While USP20 has been established as a deubiquitinating protein that stabilizes ERK3 by preventing its degradation, both TRIM21 and FBXW7 have been identified as E3 ligases that target …

Optimization Of L-Citrulline Production In Corynebacterium Glutamicum, And The Effect Of The Human Small Intestine Environment, Simran S. Ghulldu

Honors Undergraduate Theses

L-citrulline is a crucial amino acid involved in nitric oxide production, which supports cardiovascular health, physical performance, and intestinal well-being. Nitric oxide deficiency is linked to conditions like hypertension, highlighting the need for efficient L-citrulline production. This study attempts to enhance L-citrulline synthesis in Corynebacterium glutamicum, a bacterium widely used in industrial amino acid production, as well as test a The hypothesis is that overexpressing carAB, which encodes carbamoyl phosphate synthetase, will increase carbamoyl phosphate levels and boost L-citrulline production. Two C. glutamicum strains were used: a wild type and the CRBG strain, which has mutations that promote …

Temporal Dynamics Of Programmed Genome Rearrangement In Sea Lamprey Embryogenesis: A Deep Learning & Lightsheet Imaging Approach To Studying Early Developmental Transitions, Kasturi Rajandran

Theses and Dissertations--Biology

Programmed genome rearrangement (PGR) in the sea lamprey (Petromyzon marinus) leads to the elimination of ~0.5Gb (20%) of the germline genome during early embryogenesis, yet its timing relative to the maternal-to-zygotic transition (MZT) remains unclear. In this study, we imaged embryos cleared at 3-hour intervals (up to 72 hours post fertilization (hpf)) using high-resolution lightsheet fluorescence microscopy and a custom deep-learning image-analysis pipeline (~80% accuracy) to quantify nuclei and micronuclei counts. Micronuclei, which are the hallmarks of PGR first appear between 24 to 27hpf (vs ~36hpf previously reported) indicating PGR starts earlier than previously reported in the sea …

The Adiponectin-Pparγ Axis In Hepatic Stellate Cells Regulates Liver Fibrosis, Shangang Zhao, Qingzhang Zhu, Wang-Hsin Lee, Jan-Bernd Funcke, Zhuzhen Zhang, May-Yun Wang, Qian Lin, Bianca Field, Xue-Nan Sun, Guannan Li, Mbolle Ekane, Toshiharu Onodera, Na Li, Yi Zhu, Christine M. Kusminski, Terry D. Hinds Jr., Philipp E. Scherer

Markey Cancer Center Faculty Publications

Hepatic stellate cells (HSCs) are key drivers of local fibrosis. Adiponectin, conventionally thought of as an adipokine, is also expressed in quiescent HSCs. However, the impact of its local expression on the progression of liver fibrosis remains unclear. We recently generated a transgenic mouse line (Lrat-rtTA) that expresses the doxycycline-responsive transcriptional activator rtTA under the control of the HSC-specific lecithin retinol acyltransferase (Lrat) promoter, which enables us to specifically and inducibly overexpress or eliminate genes in these cells. The inducible elimination of HSCs protects mice from methionine/choline-deficient (MCD) diet-induced liver fibrosis, confirming their causal involvement in fibrosis development. We generated …

Urobilin Derived From Bilirubin Bioconversion Binds Albumin And May Interfere With Bilirubin Interacting With Albumin: Implications For Disease Pathology, Kevin I. Williams, Priyanka Suryadevara, Chang-Guo Zhan, Terry D. Hinds Jr., Zachary A. Kipp

Markey Cancer Center Faculty Publications

Background/Objectives: Bilirubin is a hydrophobic molecule that binds the carrier protein albumin for transport through systemic circulation. Bilirubin is cleared from the body through the liver and excreted into the intestines, where the microbiota modifies the chemical structure, forming urobilin, which can be reabsorbed into circulation by the hepatic portal vein. Urobilin has no known function. It is also unknown whether urobilin binds albumin for transport in circulation. We hypothesized that because of the likeness of their chemical structures, urobilin would also bind albumin like bilirubin does. Methods: First, we used in silico docking to predict if urobilin would bind …

Dissecting The Biophysical Mechanisms Of Oleate Hydratase Association With Membranes, William A. Lathram, Robert J. Neff, Ashley N. Zalla, James D. Brien, Vivekanandan Subramanian, Christopher D. Radka

Markey Cancer Center Faculty Publications

This study investigates the dynamics of oleate hydratase (OhyA), a bacterial flavoenzyme from Staphylococcus aureus, and its interactions with lipid membranes, focusing on the factors influencing membrane binding and oligomerization. OhyA catalyzes the hydration of unsaturated fatty acids, playing a key role in bacterial pathogenesis by neutralizing host antimicrobial fatty acids. OhyA binds the membrane bilayer to access membrane-embedded substrates for catalysis, and structural studies have revealed that OhyA forms oligomers on membrane surfaces, stabilized by both protein-protein and protein-lipid interactions. Using fluorescence correlation spectroscopy (FCS), we examined the effects of membrane curvature and lipid availability on OhyA binding to …

Structural Insights Into Peptidoglycan O-Acetylation In Gram-Negative Bacteria, Tyler Malloch

Theses and Dissertations (Comprehensive)

The Centres for Disease Control has acknowledged that we are entering a post-antibiotic era, where increasing numbers of bacterial pathogens are becoming resistant to known antibiotics. One of the most successfully targeted features of bacteria is also the main component of the cell wall, peptidoglycan (PG). PG is a heteropolymer of alternating sugar residues, namely N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) which are joined together by b-(1,4)-glycosidic bonds and crosslinked via stem peptide chains. PG is a target, readily lysed by exogenous and endogenous autolysins, such as lysozyme and lytic transglycosylase, respectively. This event leads to cell death …

Characterizing The Targeting Of Toc159 Receptors To The Chloroplast Outer Envelope Membrane And Their Role In The Assembly Of Distinct Toc Complexes, Michael Fish

Theses and Dissertations (Comprehensive)

Global agriculture and food security face challenges from climate change, population growth, and other human-driven pressures. Enhancing our understanding of plant biology, particularly chloroplast function, is critical for improving crop yield and stress resilience. As the sites of photosynthesis and key regulators of plant responses to environmental cues, chloroplasts depend on the precise import of thousands of nuclear-encoded proteins to maintain their biogenesis and function. While much is known about the core translocon components in the chloroplast outer envelope membrane that form the TOC complex, the mechanisms underlying their targeting, assembly, and regulation remain incompletely understood.

Plastids, including chloroplasts, evolved …

Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers

Theses and Dissertations

Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.

To …

Epigenetic Potential Remains Stable Over 100 Years After Introduction, Danielle Dawkins

College of Graduate Studies: Theses & Dissertations

Introduced species provide important insights into organismal behavioral responses. Epigenetic mechanisms are one of the various ways in which behaviors can be modified, particularly through DNA methylation. Through such mechanisms, phenotypic changes can occur in response to environmental changes, allowing an organism to be more plastic. Epigenetic potential (EP) represents the capacity for an organism to be epigenetically modified, and can be measured by counting CpG motifs; cytosine adjacent to guanine within a DNA sequence. Phenotypic plasticity as it relates to EP has been studied extensively in the house sparrow (Passer domesticus), a globally introduced songbird. It is …

Characterization Of Adaptive Quorum Sensing In Pseudomonas Aeruginosa, Kayla Simanek

Electronic Theses & Dissertations (2024 - present)

Pseudomonas aeruginosa is an opportunistic pathogen that is highly antibiotic resistant and causes tens of thousands of infections each year. It persists in hospitals by forming biofilms on medical equipment like ventilators and catheters, making it difficult to eradicate. Biofilm formation, among other virulence factors of P. aeruginosa, is regulated through quorum sensing, a mechanism of bacterial communication. Quorum sensing is primarily coordinated through LuxI-R type systems comprised of an autoinducer synthase and receptor, respectively. Canonically, the first system to be expressed is LasI-R, and LasR upregulates the second arm of the quorum sensing network, the RhlI-R system. Research …

Nature, Nurture, And Serial Murder: A Biocriminological Analysis Of Jeffrey Dahmer And Aileen Wuornos, Dori W. Jal

Honors Thesis

In recent years, there has been an increase in public fascination with serial killers, however current criminological explanations continue to focus on social and psychological factors, lacking commentary on potential biological implications. This thesis addresses a gap in the literature by examining how biological processes, specifically epigenetic, neurobiological, and endocrinological mechanisms, interact with environmental stressors to shape serial homicidal behavior. The goal is to determine whether serial murder can be more effectively understood through a biosocial framework that integrates biological vulnerability with lived experience, rather than relying on singular explanatory models.

Using a qualitative multiple-case study methodology, this research analyzes …

Bacteria-Engineered Vesicles For Cancer Immunotherapy: From Immunomodulation In Vitro To Anti-Tumor Effects In Melanoma Models, Lan Li

Theses and Dissertations--Chemistry

Bacterial vesicles hold immense potential in various biomedical fields. Among these, outer membrane vesicles (OMVs) produced by Gram-negative bacteria are the most extensively studied. While the exact mechanism of OMV production remains unclear, numerous environmental factors have been shown to influence both their yield and composition. In this study, we investigated the effect of three different antimicrobial families on OMV production by E. coli. Interestingly, antimicrobials within the same family did not provide the same effects on OMV yield, suggesting that OMV production may not directly correlate with the antimicrobial mechanism of action. OMVs have demonstrated tumor-inhibitory activity in multiple …