Life Sciences Commons^™

Studying Egfr Signaling Through Single Molecule Imaging And Computational Modeling, Emanuel Salazar Cavazos

Biomedical Sciences ETDs

Signaling through the Epidermal Growth Factor Receptor (EGFR) plays an important role in both physiological and cancer-related processes. In this work, single-molecule microscopy measurements and computational modeling were closely integrated to better understand the mechanisms that regulate EGFR signaling. Technical improvements were made over the previously described Single-Molecule Pull-down (SiMPull) assay to facilitate direct detection of the phosphorylation state of thousands of individual receptors, and thereby estimate both the fraction of receptors phosphorylated at specific tyrosine residues and the frequency of multisite phosphorylation. These improvements enabled the first direct detection of multisite phosphorylation on full-length Epidermal Growth Factor Receptor (EGFR), …

Neurocognitive Markers Of Cognitive Control In Schizophrenia And Functional Outcomes, Sephira Ryman

Psychology ETDs

Impaired cognitive function results in decreased objective quality of life and community functioning in schizophrenia, resulting in the largest indirect costs from the disease. Disrupted proactive cognitive control, a form of early selection and active goal maintenance, is hypothesized to underlie the broad cognitive deficits observed in patients with schizophrenia. The current study utilized novel electrophysiological (EEG) analytic approach to examine proactive and reactive cognitive control deficits in schizophrenia patients. Behavioral results highlight that patients exhibited a general reduction in reaction time across two multisensory cognitive control tasks, with selective deficits on proactive conditions relative to reactive conditions. The relative …

Schistosomiasis In The Wild: A Transcriptomics Perspective On Field-Derived Biomphalaria Pfeifferi And Schistosoma Mansoni, And Their Interactions, Sarah K. Buddenborg

Biology ETDs

Schistosomiasis, caused by trematodes in the genus Schistosoma, is a widespread neglected tropical disease with the species S. mansoni infecting over 100 million people. We aimed to better understand the snail host and parasite responses during intramolluscan stages of infection by performing dual RNA-Seq on field-collected snails with natural infections from western Kenya. We collected uninfected Biomphalaria pfeifferi, B. pfeifferi with a patent cercariae-producing S. mansoni infection, and B. pfeifferi exposed to field-collected S. mansoni at 1 and 3d (days post infection).

We first created a high-quality B. pfeifferi transcriptome to identify the snail response to S. mansoni infection. …

Evaluating The Aryl Hydrocarbon Receptor As A Target For Pharmacologic Activity Of Repurposed Drugs, Teofilo Borunda Duque

Pharmaceutical Sciences ETDs

The discovery of new pharmacologic targets is important for the advancement of pharmacotherapy and identification of new indications for current drugs. The aryl hydrocarbon receptor (AHR) is a physiologic sensor of both chemical environmental pollutants and ligands of natural origin. Given the broad spectrum of ligands that activate the AHR and its relationship with toxicology, the AHR is not thought to be a traditional target for pharmacotherapy. However, multiple studies have shown potential for the AHR as a novel pharmacologic target Therefore, identifying less toxic agents that modulate the AHR may elucidate mechanisms for pharmacological targeting of the AHR. The …

Moderate Prenatal Alcohol Exposure Impairs Performance In An Object-Place-Paired-Associate Task, Lilliana May Sanchez

Psychology ETDs

Memory impairments, including spatial and object processing, are often observed in individuals with Fetal Alcohol Spectrum Disorder. Much attention has been directed towards the hippocampus, which displays significant alterations after moderate prenatal alcohol exposure (PAE). In the present study, we tested a moderate PAE rat model in an object-place-paired-associate (OPPA) task, previously shown to require hippocampal processing. The OPPA task was composed of training rats to discriminate between an identical pair of objects presented in 180° opposite arms of a radial arm maze. Animals were given a total of 10 trials per day over 14 consecutive days of training and …

Cholesterol Regulation Of Pulmonary Endothelial Calcium Entry Following Chronic Hypoxia, Bojun Zhang

Biomedical Sciences ETDs

Chronic hypoxia (CH)-induced pulmonary hypertension (PH) is associated with diminished ATP-induced endothelial Ca2+ entry as well as membrane cholesterol in pulmonary arteries. Store-operated Ca2+ entry (SOCE) and depolarization-induced Ca2+ entry are major components of the response to ATP and are similarly decreased after CH. Because endothelium-dependent vasodilation is closely associated with pulmonary endothelial [Ca2+]i, the blunted agonist-induced Ca2+ influx in pulmonary artery endothelial cells (PAEC) may contribute to the development of CH-induced PH. Interestingly, impaired agonist-induced Ca2+ influx in PAEC following CH can be restored by membrane cholesterol supplementation. In the current studies, we hypothesized that impaired Ca2+ entry in …

Exploring Biological Heterogeneity And Its Consequences At Tissue And Cellular Scales Through Mathematical And Computational Modeling, Romica Kerketta

Biomedical Sciences ETDs

This dissertation explores the effects of heterogeneity across different biological scales in cancer as well as normal cells. At the tissue scale, we investigated the variability present in the tumor microenvironment and its effect on patient chemotherapeutic outcomes using a mathematical model of drug transport. We found that parameters such as tumor blood perfusion and radius of blood vessel had an impact on the tumor cytotoxicity. This indicated that the physical microenvironment of the tumor is an important regulator of the tumor response to chemotherapy. At the cellular scale, we investigated the heterogeneity present on the membrane landscape of ErbB2 …

A Multiscale Modeling Study Of The Mammary Gland, Joseph D. Butner

Biomedical Engineering ETDs

Multiscale, hybrid computer modeling has emerged as a valuable tool in the fields of computational systems biology and mathematical oncology. In this work, we present an overview of the motivations for, and development and implementation of, three hybrid multiscale models of the mammary gland system and early stage ductal carcinoma in situ (DCIS) in the gland. Pubertal mammary gland development was described first using a two-dimensional, lattice-based hybrid agent-based model description of the mammary terminal end bud (TEB), and then with a three-dimensional lattice-free TEB model. Both models implement a discrete, agent-based description of the cell scale, and a continuum, …

Cortico-Striatal Coordination Disrupted In Behaviorally Inflexible Moderate Prenatal Alcohol Exposed Mice, Kristin L. Marquardt

Biomedical Sciences ETDs

Up to 61% of adolescent school aged children with fetal alcohol spectrum disorder (FASD) have been suspended or expelled. Executive function deficits, like dis-inhibition and cognitive inflexibility, have been proposed to be better predictors of behavioral problems then IQ score, which qualifies these individuals for developmental disability and special school programs. Reversal learning, a widely used behavioral paradigm for assessing cognitive flexibility across species, has been shown to be impaired in rodent models of prenatal alcohol exposure (PAE). Here we show that a mouse model with daily maternal drinking, resulting in a BAC of 85 mg/dl throughout gestation, results in …

Cd82 Membrane Scaffolding Regulates Hematopoietic Cell Functions, Christina M. Termini

Biomedical Sciences ETDs

Through their ability to self-renew and differentiate, hematopoietic stem/progenitor cells (HSPCs) maintain the adult blood and immune systems. The microenvironment, or niche, in which HSPCs reside, serves as a critical regulator of HSPC functions. As previous work has identified the tetraspanin CD82 as a mediator of HSPC-niche interactions, we aimed to determine the mechanism by which this occurs. Our data demonstrate that CD82 expression and scaffolding regulate HSPC interactions with niche components by organizing the α4 integrin subunit into tightly packed nanoclusters. The HSPC niche can also protect acute myeloid leukemia (AML) cells from therapeutics. Therefore, we next examined how …

Validation Of The Pre-B Cell Receptor As A Therapeutic Target In B Cell Precursor Acute Lymphoblastic Leukemia, Michael F. Erasmus

Biomedical Sciences ETDs

This dissertation is built upon the fundamental idea that the pre-B cell receptor (pre-BCR) is important to leukemia cell survival and a logical therapeutic target in B cell precursor acute lymphoblastic leukemia (BCP-ALL). The pre-BCR is expressed early at a specific stage during B cell development where it plays a central role in survival of healthy B lymphocytes. This receptor is composed of the membrane heavy chain (mIgμ) associated with surrogate light chain components, 5 and VpreB. Through the use of advanced imaging modalities, in particular two-color single particle tracking (SPT), we showed that pre-BCRs formed transient, homotypic interactions. These …

Network Inference Driven Drug Discovery, Gergely Zahoránszky-Kőhalmi, Tudor I. Oprea Md, Phd, Cristian G. Bologa Phd, Subramani Mani Md, Phd, Oleg Ursu Phd

Biomedical Sciences ETDs

The application of rational drug design principles in the era of network-pharmacology requires the investigation of drug-target and target-target interactions in order to design new drugs. The presented research was aimed at developing novel computational methods that enable the efficient analysis of complex biomedical data and to promote the hypothesis generation in the context of translational research. The three chapters of the Dissertation relate to various segments of drug discovery and development process.

The first chapter introduces the integrated predictive drug discovery platform „SmartGraph”. The novel collaborative-filtering based algorithm „Target Based Recommender (TBR)” was developed in the framework of this …

The Role Of Fatty Acids And Cigarette Smoke Toxicants In Cigarette Smoke-Induced Cardiovascular Disease, Elani F. Wiest 4216058

Biomedical Sciences ETDs

Young, healthy smokers have an increased risk of developing cardiovascular disease (CVD), but early identification of these individuals can prevent progression to more severe cardiovascular diseases like atherosclerosis, stroke, and heart attacks. However, methods developed to detect cardiovascular disease in its early stages are limited and very costly. The goal of this project is to identify biomarkers that can be tested in a single blood draw from smokers in order to both assess their risk of developing cardiovascular disease and identify possible therapeutic targets to prevent disease progression.

The long term goals of this project are to investigate the association …

Alterations In Calcium Homeostasis And The Insulin-Like Growth Factor Signaling Pathway Induced By Carcinogenic Polycyclic And Halogenated Aromatic Hydrocarbons In Human Mammary Epithelial Cells, Stacey L. Tannheimer

Pharmaceutical Sciences ETDs

Breast cancer is a major health concern for women, with only a small percent of the risk factors currently identified. It has been estimated that environmental factors may contribute to up to 80% of breast cancer cases. Many environmental carcinogens, such as polycyclic and halogenated aromatic hydrocarbons (PAHs and HAHs), are proven mammary carcinogens in animal models. Therefore, these studies were conducted to elucidate potential roles of PAHs and HAHs in alterations in known signaling pathways in human mammary epithelial cells (HMEC). Carcinogenic PAHs have previously been shown to produce sustained alterations in the calcium (Ca2') homeostasis of lymphocytes Therefore, …

Alterations In Human B Cell Calcium Homeostasis By Polycyclic Aromatic Hydrocarbons: Possible Associations With Cytochrome P450 Metabolism And Increased Tyrosine Phosphorylation, Barbara J. Mounho

Pharmaceutical Sciences ETDs

Polycyclic aromatic hydrocarbons (PAHs), are known immunotoxicants in animals, and are suspect toxins to the human immune system. The mechanism(s), however, by which PAHs exert immunosuppression have not been fully elucidated. Previous studies conducted in our laboratory have shown that PAHs, such as 7,12-dimethylbenz(a)- anthracene (DMB A) and benzo(a)pyrene (BaP) may exert their immunotoxic effects by altering intracellular calcium (Ca2+) homeostasis in lymphocytes. Intracellular Ca2+ is an important second messenger in the immune response, and the mobilization of Ca2+ is critical in the transduction of intracellular signals from the plasma membrane to the nucleus. The overall objective of this project …

The Effect Of Adrenal Steroid Hormones On The Protein Content Of Tumorous Livers, Duncan W. Martin

Biology ETDs

Protein is basic to the structure and function of protoplasm. Enzyme systems which regulate the rate of cellular reactions are primarily composed of protein and many of these enzymatic systems influence the metabolism of less specialized proteins that form the major structural material of protoplasm. It is believed that experimental procedures which modify protein composition of cells may also influence the activity of intra-cellular enzymes. In experimental live cancer, it has been shown that the activities of a number of oxidative enzymes are modified as the carcinogenic process proceeds (Richmond, 1955, p.38). Furthermore, it has been demonstrated that endocrine function …