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Dynamics Of Redox-Driven Molecular Processes In Local And Systemic Plant Immunity, Philip Berg

Theses and Dissertations

The work here presents two main parts. In the first part, chapters 1 – 3 focus on dynamical systems modeling in plant immunity, whereas chapters 4 – 6 describe contributions to computational modeling and analysis of proteomics and genomics data. Chapter 1 investigates dynamical and biochemical patterns of reversibly oxidized cysteines (RevOxCys) during effector-triggered immunity (ETI) in Arabidopsis, examines the regulatory patterns associated with Arabidopsis thimet oligopeptidase 1 and 2’s (TOP1 and TOP2), roles in the RevOxCys events during ETI, and analyzes the redox phenotype of the top1top2 mutant. The second chapter investigates the peptidome dynamics during ETI …

Molecular Basis Of Viroid Rna-Templated Transcription, Shachinthaka D. Dissanayaka Mudiyanselage

Theses and Dissertations

Transcription is a fundamental process catalyzed by DNA-dependent RNA polymerases (DdRPs). Interestingly, some DdRPs can use both DNA and RNA as templates for transcription. This RNA-dependent RNA polymerase (RdRP) activity of DdRPs is used by RNA-based pathogens such as viroids and hepatitis delta virus for replication. In addition, RdRP activity of DdRPs widely occurs in various organisms to regulate gene transcription. Despite the importance of this intrinsic RdRP activity of DdRPs, associated factors and mechanisms are in their infancy stage. We employed potato spindle tuber viroid (PSTVd) as a model to study RNA-templated transcription. Here, we present evidence showing that …

Effects Of Roundup Exposure On Redox Status, Cellular Apoptosis, And Antioxidant And Osmoregulatory Enzyme Expressions In Goldfish (Carassius Auratus), Md Imran Noor

Theses and Dissertations

Intense anthropogenic activities of industrialized nations dramatically increase environmental pollution. This study focused on the effects of Roundup, a glyphosate-based herbicide, exposure (low- and high-dose: 0.5 and 5 mg/L for 2 weeks) on dinitrophenyl protein (DNP), nitrotyrosine protein (NTP), superoxidase dismutase (SOD), catalase (CAT), Na+ /K+ - ATPase (NKA), and renin expressions, and cellular apoptosis in the gills and kidneys of goldfish. Histopathological analysis showed widespread tissue damage in both gills and kidneys. Immunohistochemical analysis provided insights into the expression of molecular biomarkers in tissues. Fish exposed to Roundup exhibited a significant (P<0.05) upregulation in DNP, NTP, SOD, and CAT expressions, and apoptotic nuclei in both tissues. Additionally, exposure to Roundup significantly increased renin expression in kidneys and decreased NKA expression in gills. Overall, our results suggest that exposure to Roundup induces oxidative/nitrative stress and cellular apoptosis and alters osmoregulatory and antioxidant systems which may lead to impaired physiological functions in goldfish.

Influence Of Glucose And Lactic Acid On Macrophage Transition In Pancreatic Tumors, Anyssa A. Rodriguez

Theses and Dissertations

Pancreatic cancer is the seventh leading cause of cancer-related mortality worldwide. According to the American Cancer Society, it is the eleventh most common cancer diagnosed in both men and women in the United States. Pancreatic ductal adenocarcinoma (PDAC) comprises 90% of all pancreatic malignancies and is associated with poor clinical outcome because of late diagnosis and resistance to therapy. In addition, studies show that the tumor microenvironment has become an emerging interest in cancer research due to its complex components and unique characteristics that aid in cancer initiation, maintenance, and progression. Accumulating evidence signifies that tumor associated macrophages (TAMs) play …

Classification Models For 2,4-D Formulations In Damaged Enlist Crops Through The Application Of Ftir Spectroscopy And Machine Learning Algorithms, Benjamin Blackburn

Theses and Dissertations

With new 2,4-Dichlorophenoxyacetic acid (2,4-D) tolerant crops, increases in off-target movement events are expected. New formulations may mitigate these events, but standard lab techniques are ineffective in identifying these 2,4-D formulations. Using Fourier-transform infrared spectroscopy and machine learning algorithms, research was conducted to classify 2,4-D formulations in treated herbicide-tolerant soybeans and cotton and observe the influence of leaf treatment status and collection timing on classification accuracy. Pooled Classification models using k-nearest neighbor classified 2,4-D formulations with over 65% accuracy in cotton and soybean. Tissue collected 14 DAT and 21 DAT for cotton and soybean respectively produced higher accuracies than the …

Complex Regulatory Pathways Connect Vfm Quorum-Sensing And Cyclic-Di-Gmp Signaling To Bacterial Virulence In The Phytopathogen Dickeya Dadantii 3937, Biswarup Banerjee

Theses and Dissertations

The bacterial second messenger Bis-(3’-5’)-cyclic dimeric guanosine monophosphate (c-di-GMP) regulates multiple cellular behaviors in most bacteria. Bacterial c-di-GMP signaling involves enzymes that synthesize and degrade c-di-GMP, c-di-GMP binding effectors, and targets that are acted upon by the effectors. So far, the c-di-GMP signaling pathways have been understudied. In this work, we explore the c-di-GMP signaling network further in the phytopathogen Dickeya dadantii 3937. In Chapter 2, we identified VfmE as a c-di-GMP binding transcriptional activator that represses pectate lyase production under a high c-di-GMP condition. VfmE was found to bind c-di-GMP in vitro via the RxxxR motif, similar to PilZ …

Characterization Of The Responses To Chronic Stress In Caenorhabditis Elegans, Amy Laura Knight

Theses and Dissertations

Exposure to chronic temperature stress influences organismal phenotypes that are important for human health, agriculture, and ecology. In this thesis, the model organism Caenorhabditis elegans was used to study the effects of temperature stress on reproduction and lifespan. It was found that worms demonstrated a rapid shut down in egg-laying between 18-24 hours of exposure to 28°C. Despite this reproductive defect, the overall lifespan of worms was unaffected. At the molecular level, heat shock factor 1 (HSF-1), a regulator of the protective molecular pathway known as the heat shock response (HSR), was identified as important for progeny production during heat …

Targeting Ribosome Biogenesis For Pancreatic Cancer Treatment, Carlos Perez Iii

Theses and Dissertations

Pancreatic cancer (PanCa) is one of the leading causes of cancer-related death in the United States. Currently, PanCa is one of the recalcitrant cancers that has very limited therapeutic options available for its treatment. The current standard care of PanCa is gemcitabine (GEM) alone or in combination with FOLFIRINOX, nab-paclitaxel, erlotinib, or 5-FU PanCa, which often show poor response. Therefore, new treatment strategies are required for the prevention and treatment of cancer. Ribosome biogenesis process is dysregulated in most of the cancer types of results in production of more ribosomes and synthesis of oncoproteins which lead to the induction, progression, …

Targeting Mutated Kras And Galectin-1 In Pancreatic Cancer, Ana Izavelle Martinez Bulnes

Theses and Dissertations

The poor patient survival rate in pancreatic ductal adenocarcinoma (PDAC) remains a challenge. KRAS activating point mutation on codon-12 is found in 70–95 percent of PDAC patients, and no progress in inhibiting KRAS has been obtained thus far. KRASG12D is a transcription factor that controls cell proliferation, differentiation, and apoptosis. Recent preliminary and published research indicates that Galectin-1 (Gal-1) levels are high in both PDAC and stromal cells, which modulates tumor microenvironment and metastasis. As a result, we created a new combination treatment for PDAC that targets both proliferation and metastasis in PDAC by targeting mutant KRASG12D and Gal-1. This …

The Apoe Ε4 Allele Association With Cholesterol Related Phenotypes In The Mexican American Population, Stephanie Lozano

Theses and Dissertations

Diseases linked to high cholesterol have been well studied and several diseases-associated candidate genes have been suggested. Among these, the apolipoprotein E gene (APOE) gene associated with lipid metabolism and lipid-related traits was reported in the non-Hispanic population. There are three types of alleles APOE ε2, ε3, and ε4. The APOE ε4 allele has been identified as a biomarker for Alzheimer’s disease (AD) and cardiovascular disease (CVD). In recent years, there have been limited studies regarding the association between the APOE gene and hypercholesterolemia in the Mexican American population. Therefore, the aim of this study is to investigate …

Screening For Potential Therapeutic Targets Of Yb-1 Protein Using A Bioinformatics Approach, Omar Muneer Karkoutly

Theses and Dissertations

Treatment options for cancer are becoming much more limited due to the robust characteristics of cancer that allows them to rapidly develop drug resistance. This may be a result of cancer cells’ ability to switch between differentiated and undifferentiated states (plasticity). Diagnostic measurement and detection of cancer and its progression is essential for developing successful treatments. Specific cancer targets whose expressions are highly associated with increased incidence, risk, and spread of cancer therefore become perfect targets for therapeutic intervention. One such novel target that is still being studied is the Y-box binding protein 1 (YB-1), which …

Influence Of Paclitaxel Nanomedicine On The Pancreatic Tumor Immune Components, Godwin Peasah-Darkwah

Theses and Dissertations

Pancreatic cancer (PanCa) is one of the leading causes of cancer-related mortalities in the U.S due to ineffective therapeutic options. Pancreatic tumors are highly desmoplastic and inhibit efficient uptake of therapeutic payloads. Paclitaxel (PTX) has been tested in PanCa therapy with marginally better clinical outcomes, but remain limited by its poor hemocompatibility, biodistribution and intracellular accumulation in tumor cells. Thus, we synthesized a next generation nanoparticle system for PTX to improve its pharmacokinetics and pharmacodynamics (PKPD) in treating PanCa. We also examined ability of the nano formulation to potentiate gemcitabine (GEM) activity in combating chemoresistance in the pancreatic tumor microenvironment …

Cucurbitacin B: A Potential Natural Agent For Targeting Tumor Immune Cell Population, Emmanuel Anning

Theses and Dissertations

Immune checkpoint blockade (PD1, PDL-1 and CTLA-4) immunotherapies have emerged as the breakthrough in cancer treatment. However, some malignancies show marginal response. One factor that influences the efficacy of immunotherapy is the development of immunosuppressive tumor microenvironment (TME), caused by infiltration of myeloid derived suppressor cells (MDSCs) and tumor associated macrophages (TAM) into the tumor, facilitating metastatic tumor growth and immunotherapy resistance. We have identified Cucurbitacin B (Cuc. B), a potent small molecule that targets TAM and MDSCs and inhibits Stat3, CSF-1R, and PI3Kγ signaling axis at lower doses compared to the pharmacological inhibitor of PI3Kγ (IPI-549). IL-4 polarization of …

Studies On The Impact Of An Insect Growth Regulator And Host Plant On Reproductive Physiology Of Lygus Lineolaris, James Houston Chance Anderson

Theses and Dissertations

The tarnished plant bug, Lygus lineolaris, is an economically important polyphagous pest with a broad host range. With occurrence of insecticide resistance, strategies to limit its ability to reproduce, which would curb population growth, are becoming increasingly more valuable. Strategies toward this goal include the application of insect growth regulators (IGRs) and utilization of resistant cotton lines. This thesis summarizes experiments that elucidate the physiological underpinnings of the mode of action of novaluron, an IGR, and a cotton chromosome substitution (CS) line on the reproductive physiology of L. lineolaris. Investigations reported herein indicate that novaluron inhibits oviposition by …

Optimized Selenium Status, Gut Microbiota, And Type 2 Diabetes, Ying-Chen Huang

Theses and Dissertations

We have previously demonstrated that long-term dietary Se deficiency in old Terc^-/- mice with humanized telomeres induces type-2 diabetes and exacerbates age-dependent increases in the abundance of A. muciniphila and Lachnospiraceae, which are related to obesity and metabolic syndromes. The objectives of this dissertation are: 1) to determine the minimum intake of Se required for type 2 diabetes prevention in middle-aged mice; 2) to evaluate the efficacy of A. muciniphila and R. torques (a Lachnospiraceae family member) to intervene dietary Se deficiency-induced type 2 diabetes and the underlying mechanisms; 3) to assess sex differences in the responses to …

Novel Strategies In Near Infrared Spectroscopy (Nirs) And Multivariate Analysis (Mva) For Detecting And Profiling Pathogens And Diseases Of Agricultural Importance., Johjan Mariana Santos Rivera

Theses and Dissertations

The time required for the identification of pathogens is an important determinant of infection-related mortality rates and disease spread for species of relevance in agriculture. Conventional identification methods require a processing time of at least one to twenty days. Therefore, inaccurate empirical treatments are often provided while awaiting further identification, such that most cases progress with further aggravation of symptoms, contamination of other animals or plants, generating economic loss from decreased yield, and increased mitigation costs. Thus, there is a need for innovative, non-destructive, and rapid analytical techniques that provide reagent-free, portable, reliable, and holistic approaches to detect diseases in …

The Effects Of An R103q Mutation On The Chemical And Physical Properties Of The Enzyme Cytochrome C Nitrite Reductase (Ccnir), Shahama Alam

Theses and Dissertations

Cytochrome c Nitrite Reductase (ccNiR) is a periplasmic homodimeric decaheme enzyme that catalyzes the reduction of nitrite to ammonium in a process that involves six electrons and eight protons. The project described herein explored the properties of the Shewanella oneidensis R103Q ccNiR variant and compared them to the properties of the wild type enzyme. Under standard assay conditions, which use the strong reducing agent methyl viologen monocation radical (MVred) as an electron source, the R103Q variant still catalyzes reduction of nitrite to ammonium, albeit with an MVred turnover rate that is 20% of the wild type’s (780 ± 50 s-1 …

Zinc-Mediated Regulatory Function Of Psd-95 On Nmdar At Post-Synapses, Luis F. Acosta

Theses and Dissertations

Postsynaptic density-95 (PSD-95) is a membrane-associated guanylate kinase that mediates localization of receptors in the excitatory postsynaptic density. It has been reported that PSD-95 mediates postsynaptic localization of NMDA receptors and anchors postsynaptic AMPAR receptors mainly through its postsynaptic membrane targeting by its N-terminal palmitoylation. Recent studies have shown that Ca2+/calmodulin blocks palmitoylation of PSD-95 by binding at the N-terminus of PSD-95, which promotes dissociation of PSD-95 from the postsynaptic membrane and causes loss of surface AMPARs in cultured neurons. Another metal ion zinc is found in various areas of the brain. As an endogenous neuromodulator, zinc plays a role …

Exploring Dna Compaction Via Bacillus Subtilis Parb Protein By Single Molecule Investigation, Miranda L. Molina

Theses and Dissertations

Faithful chromosome segregation involves ParB, a DNA-binding and compacting protein that specifically recognizes parS DNA sites near the replication origin. ParB spreads 10-20 kb from parS sites, which recruitments additional ParB molecules to neighboring DNA, forming higher-order nucleoprotein complexes. ParB is also a novel CTPase enzyme and hydrolyses CTP to self-dimerization and create a clamp that slides along DNA. To understand the roles of CTP in Bacillus subtilis ParB (BsParB), we purified wild type ParB (BsParB (WT)) and recombinant ParB (BsParB(R80A)) mutant. BsParB(R80A) was known to prevent CTP binding and not compact DNA. Proteins N- and C-terminally appended with a …

The Effects Of Hybridization On Skeletal Morphology In Two Closely Related Populations Of Rhesus Macaques (Macaca Mulatta): A Geometric Morphometric Approach, Cody Zachery Schumacher

Theses and Dissertations

Precise identification and classification techniques are vital for the field of paleoanthropology to ensure that hominin fossilized remains are labeled accurately. The morphology of extinct hominin specimens will typically be compared to extant nonhuman primate species because of how closely related they are phylogenetically. Observable similarities in their morphological variation can be examined to infer which traits may be a result of evolution and this can update our understanding of their evolutionary relationships. The genus Macaca displays a level of morphological variation that is similar to that seen in the genus Homo, therefore macaques can be used as an analogous …

Molecular Evolution And Biogeography Of The New World Eptesicus Bats, Xueling Yi

Theses and Dissertations

Molecular evolution refers to a broad field of studies ranging from microevolution (e.g., population genetics) to macroevolution (e.g., phylogeny), including the bridging field of phylogeography. In natural populations, molecular studies are also combined with biogeography that links biological diversity with geographic distributions to provide a comprehensive understanding of evolutionary processes. The field of molecular evolution has been largely advanced from early exploratory descriptions to statistical tests on biological hypotheses and integrative analyses using sophisticated modeling. However, studies of molecular evolution still face some unresolved questions and challenges, especially in non-model systems. For example, the application of new technology has largely …

Nanostructured Materials For Biomedical Applications, Silverio Lopez

Theses and Dissertations

Nanotechnology has been used in an increasing number of applications in biochemistry and molecular biology. Compared to bulk materials, nanoscale materials offer a variety of advantages in applications due to an increased surface-to-volume ratio of the reactants. The unique properties of nanostructured materials and their properties such as stability, reactivity, magnetic response, pressure discharge performance and biocompatibility depend on particle size and shape. This work focuses on a nanoenergetic material composed of Aluminum (Al), Copper II oxide (CuO), and Iodine (I) pentoxide (I2O5), and the biomedical application of nanoscale dextran-coated magnetite (Fe3O4), which was produced using microfluidics to tune particle …

Targeting Protein Synthesis In Clostridioides Difficile To Develop Antimicrobial Candidate, Elvira L. Alanis

Theses and Dissertations

Clostridioides difficile is a gram positive, spore forming, obligate anaerobic bacterium that causes Clostridioides difficile infection (CDI) which can result in pseudomembranous colitis and toxic megacolon. In the case of this research a focus on Protein synthesis is made since it is an essential metabolic process and is a validated target for antibiotics. Protein synthesis begins with Initiation which includes the three translation initiation factors. Through the NMR chemical shift assignments, the IF1 structure was determined, and it was found to be composed of a short α helix and five β helixes. A peptide was designed after the short α …

Assessing The Effects Of Levonorgestrel (Lng) On Neural Differentiation In The Developing Hypothalamus Using The Zebrafish (Danio Rerio) As A Model, Gabriella Hinojosa

Theses and Dissertations

Neurogenesis is a critical component of fetal neurodevelopment consisting of: migration, proliferation and differentiation. Health concerns from anxiety to reproductive issues have been linked to alterations of neurogenesis processes. Endocrine disrupting chemicals (EDCs) can mimic hormones vital to this process, potentially adversely affecting the susceptible fetal brain. One EDC, Levonorgestrel (LNG), is a testosterone-like progestin used in birth control methods that has a high bioavailability and long half-life. Using zebrafish embryos as a model, this lab previously discovered that an environmentally relevant LNG dose (5 ng/L) significantly increased anxiety behaviors. The hypothalamus is responsible for the development …

Development Of New Treatments For Asthma And Neuropathic Pain Based On Ɣ-Aminobutyric Acid A Receptor (Gabaar) Ligands, Nicolas Mark Zahn

Theses and Dissertations

The γ-aminobutyric acid A receptor (GABAAR) is a ligand-gated pentameric chloride channel consisting of several identified subunits: α1-6, β1-3, γ1-3, δ, ε, π, θ, ρ1-3.1-2 Typical arrangement of subunits consists of two α subunits, two β subunits, and one γ subunit.3 GABAARs have two binding sites for the endogenous ligand γ-aminobutyric acid (GABA), between the α and β subunits. GABAARs also have a binding site for positive allosteric modulators, such as benzodiazepines, between the α and γ subunits.4-5 Due to their ability to treat anxiety, epilepsy, insomnia, and muscle relaxation, benzodiazepines are widely prescribed pharmaceuticals.6-7 Still, adverse effects result from …

Structures And Regulations Of Translation Initiation Factors In Pseudomonas Aeruginosa Protein Biosynthesis To Develop New Potential Antimicrobial Agents, Nicolette Valdez

Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative, multidrug resistant bacterium that has been recognized as the prominent cause of nosocomial infections. Untreated acute and chronic infections associated with P. aeruginosa can develop into other diseases such as pneumonia, otitis externa, and osteomyelitis. P. aeruginosa infections commonly affect immunocompromised individuals such as cystic fibrosis, cancer, and burn patients. The misuse and overuse of antibiotics has contributed to the increased antibiotic resistance in P. aeruginosa and thus has led to an unmet need for discovery of novel antibiotic candidates. Protein biosynthesis is an essential metabolic process occurring in all bacteria and a validated target …

Eukaryotic Initiation Factor 4e (Eif4e) In Complex With Eif4e Binding Protein 1 (4e-Bp1) Binds With Higher Affinity To M7gpppn Cap Of A Subset Of Human Mrnas, Izza F. Nawaz

Theses and Dissertations

Fluorescence anisotropy binding assays were used to analyze the binding of eIF4E in complex with 4E-BP1 onto the 5’ m7G cap of a subset of mRNA that are known to carry cap-independent translation. These studies suggest that 4E-BP1 increases eIF4E binding affinity to 5’cap of both FGF-9 and HIF-1𝝰.

Repurposing Metformin And Antifolates For The Treatment Of Hepatocellular Carcinoma, Sherouk Mohamed Tawfik

Theses and Dissertations

Hepatocellular carcinoma (HCC), one of the most prevalent types of cancers worldwide, continues to maintain high levels of resistance to standard therapy. As clinical data revealed poor response rates, the need for developing new methods has increased to improve the overall wellbeing of patients with HCC. Due to its safety, wide availability and previously reported anti-cancer effects, metformin (MET) serves to be a possible therapeutic agent when combined with other well-known anti-cancer agents. The aim of this study was to investigate the potential anti-cancer effects of MET, an anti-diabetic agent, when combined with two antifolate drugs: trimethoprim (TMP) or methotrexate …

Identification Of Novel Phosphorylation Sites In Sars-Cov-2 Nucleocapsid Protein, Josie Daldegan Rezende

Theses and Dissertations

COVID-19, the 2019 disease outbreak, continues to cause severe mortality worldwide. Fast and reliable tests that identify the SARS-CoV-2 virus, which is responsible for causing the COVID-19 disease, are crucial for controlling the spread of the virus. Antigen tests are ideal for the rapid diagnosis of COVID-19. Current antigen tests for COVID-19 detect the SARS-CoV-2 nucleocapsid (N) protein. The nucleocapsid is the most abundant protein produced by the virus upon infection, which makes it a superior target for detection by an antigen test. Nucleocapsid proteins from several coronaviruses, including SARS, have previously been shown to be modified by posttranslational modification …

Protein Structure And Interaction: The Role Of Aromatic Residues In Protein Structure And Interactions Between Pyridoxine 5'-Phosphate Oxidase/Dopa Decarboxylase, Mohammed H. Al Mughram

Theses and Dissertations

Naturally developed proteins are capable of carrying out a wide variety of molecular functions due to their highly precise three-dimensional structures, which are determined by their genetically encoded sequences of amino acids. A thorough knowledge of protein structures and interactions at the atomic level will enable researchers to get a deep foundational understanding of the molecular interactions and enzymatic processes required for cells, resulting in more effective therapeutic interventions. This dissertation intends to use structural knowledge from solved protein structures for two distinct objectives.

In the first project, we conducted a bioinformatics structural analysis of experimental protein structures using our …