Disease Modeling Commons^™

The Diseased Extracellular Matrix In Chronic Obstructive Pulmonary Disease Modeling, Leigh-Ann M. Antczak

Theses and Dissertations

Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death in the world, with an increasing prevalence as the world’s population ages. In the distal regions of the lungs, COPD is characterized by progressive emphysema due to an imbalance of proteases that continuously degrade essential extracellular matrix (ECM) proteins within the alveolar walls, causing fatal tissue impairment. This dissertation examines the unique properties of this diseased lung ECM in two parts: (1) As a key constituent in inflammatory signaling that leads to increased inflammation and progression of COPD, and (2) as a tool in three-dimensional (3D) in …

Opioid Tolerance And Withdrawal In The Mouse Colon, James Fune

Theses and Dissertations

Constipation is a major clinical obstacle associated with opioids, prompting patients to discontinue treatment due to pain, discomfort, and psychosocial stressors. Moreover, chronic users become tolerant to the analgesic effects of opioids, but not to their constipating effects. Upon cessation of long-term treatment, serious diarrhea–among other somatic signs of withdrawal–may ensue. These symptoms become a driving factor for relapse, causing patients to restart opioid treatment. In this study, we aim to understand mechanisms that contribute to opioid tolerance and withdrawal in the colon. Previous findings suggest that constipation occurs partly due to the colon’s lack of tolerance to opioids’ inhibitory …

Metabolic Adaptation Of Staphylococcus Aureus Pathogenesis And Therapeutic Approach In Diabetic Foot Ulcers., Carol L. Baker

Theses and Dissertations

37.3 million Americans (11.2% of the US population) currently have Type 2 diabetes mellitus (T2DM) with over 1.5 million new cases being diagnosed each year. The multifactorial etiology of the patient having neuropathy, overweight/obesity, foot deformities, ischemia, and infection leads to a condition called diabetic foot ulcer (DFU). One in six patients with a DFU will require amputation with infected DFUs have a 155-fold increased risk of amputation. Staphylococcus aureus is the most common bacteria isolated from severe DFU infections that require amputation. Interestingly, diabetics are more heavily colonized with S. aureus compared to non-diabetics suggesting a unique advantageous adaptation …

Cost-Effectiveness Of Interventions Targeting Hard-To-Reach Populations Living With Hiv In Eastern And Southern Africa, Deo Mujwara

Theses and Dissertations

In Eastern and Southern Africa, hard-to-reach populations (e.g., long distance truck drivers and female sex workers), defined as populations that are difficult to interact or engage with due to their unique behaviors and characteristics, are disproportionately affected by the HIV epidemic and are at high-risk of acquiring and transmitting HIV. Further, these populations have substantially low uptake of HIV testing services, and those that have been diagnosed with HIV and on antiretroviral therapy experience high loss-to-follow-up from treatment programs.

Hard-to-reach populations face unique barriers in accessing and utilizing routine HIV care such as provider stigmatization towards sex workers and highly …

Stat5a Regulation By Serine Phosphorylation In Breast Cancer, Alicia E. Woock

Theses and Dissertations

The neuroendocrine hormone prolactin (PRL) and its cognate receptor (PRLr) have been implicated in the pathogenesis of breast cancer. PRL signaling relies on activating kinases such as the tyrosine kinase Jak2 and serine/threonine kinases ERK1/2, NEK3, PI3K, and AKT. In the canonical pathway of PRL signaling, JAK2 phosphorylates the transcription factor STAT5a at tyrosine residue 694 (pY694-STAT5a), preceding STAT5a nuclear translocation and transcriptional activity. However, STAT5a exists with functional duality as a transcription factor, having both pro-differentiative and pro-proliferative target genes. Other STAT family members (STATs 1, 3, and 6) have been shown to have transcriptional activity in the un-tyrosine-phosphorylated …

Novel Strategies To Overcome Carboplatin Resistance In Triple Negative Breast Cancer Using Patient Derived Xenografts, Mohammad A. Al Zubi

Theses and Dissertations

Triple-negative breast cancer (TNBC) patients have a poor prognosis and rely on chemotherapeutic treatment as standard of care. Often, they develop chemotherapy resistance, which leaves them without more therapeutic options, like targeted therapy. New models have been developed to test targeted inhibitors in human tumors, and they are known as patient-derived xenografts (PDX). These tumors are obtained from patients, then established and maintained in mice where they areused for tumor studies. In this work, we characterized 14 PDXs for their primary tumor growth rate and investigated metastatic propensity using spontaneous and experiment metastasis models. We utilized RNA-sequencing to characterize contributions …

The Role Of Manganese In Streptococcus Sanguinis, Tanya M. Puccio

Theses and Dissertations

Streptococcus sanguinis is primarily associated with oral health as a commensal bacterium. As an opportunistic pathogen, S. sanguinis is capable of colonizing heart valve vegetations, leading to the disease infective endocarditis. Previous studies from our lab have identified the high-affinity manganese transporter SsaACB as important for endocarditis virulence. The impact that manganese depletion has on S. sanguinis had never been evaluated and a secondary manganese transporter has not been identified. Thus, we employed the use of a fermentor to control large-scale growth over time and depleted manganese in an ΔssaACB mutant using a metal chelator, EDTA. The changes in …

Signaling Mechanism Responsible For 5-Ht2a Receptor Tolerance To Psychedelic Induced Head-Twitch Behavior In Mice, Audrey R. Mcmurtrie

Theses and Dissertations

In recent years, there has been a growing interest in psychedelic compounds stemming from their promising use as therapeutic agents and research tools that can be used to treat and study several neuropsychiatric disorders. Psychedelics have proven useful in a broad range of these diseases - they serve as models for psychosis in schizophrenia but have also had promising results in treating major depressive disorder, anxiety, and other common disorders. Decreased stigmatization surrounding psychedelics has further increased their use in research and clinical settings. In light of these trends and the promising nature of their use, a thorough understanding of …

The Impact Of Aging And Mechanical Injury On Alveolar Epithelial And Macrophage Responses In Acute Lung Injury And Inflammation, Michael S. Valentine

Theses and Dissertations

Patients with severe lung pathologies, such as Acute Respiratory Distress Syndrome (ARDS), often require mechanical ventilation as a clinical intervention; however, this procedure frequently exacerbates the original pulmonary issue and produces an exaggerated inflammatory response that potentially leads to sepsis, multisystem organ failure, and mortality. This acute lung injury (ALI) condition has been termed Ventilator-Induced Lung Injury (VILI). Alveolar overdistension, cyclic atelectasis, and biotrauma are the primary injury mechanisms in VILI that lead to the loss of alveolar barrier integrity and pulmonary inflammation. Stress and strains during mechanical ventilation are believed to initiate alveolar epithelial mechanotransduction signaling mechanisms that contribute …

Molecular And Behavioral Mechanisms Mediated Paclitaxel-Induced Changes In Affect-Like Behavior In Mice, Julia Meade

Theses and Dissertations

Paclitaxel and oxaliplatin are two chemotherapeutics that cause acute neurotoxicity and chemotherapy-induce peripheral neuropathy (CIPN) in 70-90% of cancer patients. Chemotherapy-induced sensory changes are correlated with depression and anxiety. We characterized the effects of these drugs on sensation and various mood-related behaviors in mice, to determine if changes in sensation are associated with depression-like behavior, to explore putative mechanisms of chemotherapy-induced depression-like behavior (Aim 1), and to develop a mouse model of chemotherapy-induced operant responding deficit (Aim 2). In Aim 1, we observed that a cumulative dose of 32 mg/kg paclitaxel induced mechanical hypersensitivity and transiently reduced preference for sucrose …

Examination Of Strain-Dependent Differences In S. Sanguinis Virulence And Growth, Shannon Baker

Theses and Dissertations

Streptococcus sanguinis, an abundant and benign inhabitant of the oral cavity, is an important etiologic agent of infective endocarditis, particularly in people with pre-disposing cardiac valvular damage. Although commonly isolated from patients with IE, little is known about the factors that make any particular S. sanguinis isolate more virulent than another or, indeed, whether significant differences in virulence exist among isolates. To investigate the virulence of multiple isolates, a variation of the Bar-seq (barcode sequencing) method was employed. A conserved chromosomal site was identified for subsequent insertion of a barcode identifier, unique for each strain. Barcode insertion did not …

Long-Term Effects Of Notch1 Signaling On Neural Stem Cells Following Traumatic Brain Injury, Cruz Sevilla Jr

Theses and Dissertations

Traumatic brain injury (TBI) is a devastating problem which stands as a leading cause of death and disability. The elderly is significantly affected by TBI, typically as the result of falls, and recovery is especially limited. This, in part, is associated with decreased tissue-specific stem cell regeneration and replacement of damaged cells in the aged brain. The diminished ability of the aged brain to recover is especially devastating after TBI, likely leading to permanent loss of sensory, motor, and cognitive functions. Studies have shown that the mature mammalian brain contains Neural Stem Cells (NSCs), found in specific regions of the …

Age-Dependent Changes In Oxygen Supply And Demand Of Rat Spinotrapezius Muscle, Sami C. Dodhy

Theses and Dissertations

Because of the aerobic nature of cellular metabolism in mammalian organisms, a continuous supply of oxygen is necessary to maintain normal physiological function. As organisms age, their metabolic rates generally decline and there are accompanying alterations in the structure and function of the microcirculation, as this part of the cardiovascular system is especially important for oxygen exchange. The overall Oxygen Transport System can be considered as being composed of two complementary components: one for Oxygen Demand and one for Oxygen Supply. The purpose of the current work is to describe the age-dependent changes in both oxygen demand and oxygen supply …

Investigating Smoke Exposure And Chronic Obstructive Pulmonary Disease (Copd) With A Calibrated Agent Based Model (Abm) Of In Vitro Fibroblast Wound Healing., James A. Ratti

Theses and Dissertations

COPD is characterized by tissue inflammation and impaired remodeling that suggests fibroblast maintenance of structural homeostasis is dysregulated. Thus, we performed in vitro wound healing experiments on normal and diseased human lung fibroblasts and developed an ABM of fibroblasts closing a scratched monolayer using NetLogo to evaluate differences due to COPD or cigarette smoke condensate exposure. This ABM consists of a rule-set governing the healing response, accounting for cell migration, proliferation, death, activation and senescence rates; along with the effects of heterogeneous activation, phenotypic changes, serum deprivation and exposure to cigarette smoke condensate or bFGF. Simulations were performed to calibrate …

A Mechanistic Study Of An Ipsc Model For Leigh’S Disease Caused By Mtdna Mutataion (8993 T>G), John P. Galdun

Theses and Dissertations

Mitochondrial diseases encompass a broad range of devastating disorders that typically affect tissues with high-energy requirements. These disorders have been difficult to diagnose and research because of the complexity of mitochondrial genetics, and the large variability seen among patient populations. We have devised and carried out a mechanistic study to generate a cell based model for Leigh’s disease caused by mitochondrial DNA mutation 8993 T>G. Leigh’s disease is a multi-organ system disorder that depends heavily on the mutation burden seen within various tissues. Using new reprogramming and sequencing technologies, we were able to show that Leigh’s disease patient fibroblasts …

Functional Characterization Of Rai1 In Zebrafish, Joshua S. Beach

Theses and Dissertations

Smith-Magenis Syndrome (SMS; OMIM #182290) is a multiple congenital abnormality and intellectual disability (ID) disorder caused by either an interstitial deletion of the 17p11.2 region containing the retinoic acid induced-1 (RAI1) gene or a mutation of the RAI1 gene. Individuals diagnosed with SMS typically present characteristics such as ID, self-injurious behavior, sleep disturbance, ocular and otolaryngological abnormalities, craniofacial and skeletal abnormalities, neurological and behavioral abnormalities, as well as other systemic defects and manifestations. Previous work by Vyas in 2009 showed temporal expression of rai1 in zebrafish embryos as early as 9 hpf. We hypothesize that there is maternal …

Analysis Of The Role Of Astrocyte Elevated Gene-1 In Normal Liver Physiology And In The Onset And Progression Of Hepatocellular Carcinoma, Chadia L. Robertson

Theses and Dissertations

First identified over a decade ago, Astrocyte Elevated Gene-1 (AEG-1) has been studied extensively due to early reports of its overexpression in various cancer cell lines. Research groups all over the globe including our own have since identified AEG-1 overexpression in cancers of diverse lineages including cancers of the liver, colon, skin, prostate, breast, lung, esophagus, neurons and neuronal glia as compared to matched normal tissue. A comprehensive and convincing body of data currently points to AEG-1 as an essential component, critical to the progression and perhaps onset of cancer. AEG-1 is a potent activator of multiple pro-tumorigenic signal transduction …