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Dynamics Of Nucleosome Assembly Characterized By Atomic Force Microscopy, Tommy Stormberg

Theses & Dissertations

Nucleosomes are the basic repeating unit defining the assembly and function of chromatin. Understanding the fundamental mechanisms of nucleosome structure and dynamics is critical to elucidating the chromatin assembly process. This dissertation describes my work in elucidating the role of different factors that drive the nucleosome dynamics.

In my first study, we characterized, for the first time, the effect of sequence on nucleosome assembly. We then characterized the role of internucleosomal interactions, discovering a critical role internucleosomal interactions in the assembly of higher order structures.

Based on the previous study and literature regarding histone tails, we hypothesized the histone H4 …

The Role Of Parkin In Mitochondrial Dna, Eliezer Lichter

Theses & Dissertations

Mitochondria are at the center of biological phenomena such as aging and diseases, especially neurodegenerative diseases. While the discovery of mitochondria only came approximately 200 years after the cell was discovered, a lot of progress has been made since. The mitochondrial genome encodes proteins vital for mitochondrial function. These proteins are only a subset of the proteins present in mitochondria; the rest are nuclear encoded. The nucleus also encodes cytosolic proteins vital for mitochondrial maintenance. One of these is Parkin, an E3 ubiquitin ligase that ubiquitinates mitochondrial proteins as mitochondria become depolarized. Its activity has been shown to be involved …

Crispr Technology As An Antiviral In Dsdna And Ssrna Viruses, Cathryn Mayes

Theses & Dissertations

The COVID-19 pandemic highlights the necessity of emergency response and pandemic preparedness, especially for emerging viral threats. Currently, virus-specific vaccines and antivirals are the primary tools to combat viral diseases; however, broad-spectrum antivirals that target more than one virus species could provide additional protection from emerging and re-emerging viral diseases (Andersen et al. 2020; Zhu et al. 2015; Hickman et al. 2022).

Clustered regulatory interspaced short palindromic repeat (CRISPR)-associated endonucleases have become recently utilized as potential antiviral strategies due to their high specificity, efficacy, and versatility (Najafi et al. 2022). While CRISPR-based antivirals have previously been used to target specific …

Metoprolol Disrupts Sterol Biosynthesis Through Inhibition Of 7-Dehydrocholesterol Reductase (Dhcr7), Luke B. Allen

Theses & Dissertations

Cholesterol is essential for life. It is particularly important in the brain as it relies on de novo synthesis of cholesterol following the formation of the blood brain barrier (BBB). As such, disrupting sterol biosynthesis during neurodevelopment can have devastating outcomes. The most common post-lanosterol sterol biosynthesis disorder, Smith-Lemli-Opitz Syndrome, arises from a faulty DHCR7 enzyme. DHCR7 has also been shown to be inhibited by several psychotropic medications. Here we assess six beta-blockers and their effects on sterol biosynthesis in vitro. Two beta-blockers, metoprolol and nebivolol strongly inhibit DHCR7 in four separate in vitro models of both mouse and …

Hepatocyte-Hepatic Stellate Cell Axis In Potentiation Of Alcohol And Hiv-Induced Liver Injury, Moses O. New-Aaron

Theses & Dissertations

Human Immunodeficiency Virus (HIV) remains a global threat, with approximately 38.4 million active infections and 33 million HIV-related deaths since the first case. While many may be tempted to think of HIV as a relic of the past, emerging data suggests otherwise. By the end of 2021, approximately 1.5 million HIV incidences and 650 000 mortalities were reported globally. The etiologies of HIV-related mortality are numerous. Liver disease is one of the leading etiologies of HIV-related mortality, especially in recent times of antiretroviral therapy (ART)-induced longevity among people living with HIV (PLWH). While co-infections with hepatotropic viruses notoriously contribute to …

A Cell Culture Model To Study Tobacco Associated Oral Cancer Progression And Treatment Resistance, Amanda Busch

Theses & Dissertations

Head and Neck Squamous cell carcinoma is the 6^th most common cancer in the world. Risk factors for HNSCC include alcohol and tobacco consumption, infection with Human Papilloma Virus, and exposure to environmental toxins. Unlike many other cancers, the incidence of HNSCC is growing, yet the treatment options and outcomes have not been significantly improved for decades. An increased understanding of the molecular mechanisms of these cancers is needed for improvement in early diagnosis, enhanced treatment effectiveness, and cancer prevention. 4-nitroquinoline 1-oxide (4NQO) is a well-tested, tobacco mimicking, carcinogen. 4NQO produces similar histological and chemical changes found in human …

The Role Of Ubiquitin E3 Ligase Fbxo21 In Steady-State, Stressed, And Malignant Hematopoiesis, Karli J. Wittorf

Theses & Dissertations

Hematopoietic stem cells (HSCs) allow for the formation of all cell types in the blood and maintain these populations throughout a person’s life. The process of hematopoiesis is regulated through a variety of molecular mechanisms that are either signaled from the cell’s environment (extrinsic) or from within the cell itself (intrinsic). One intrinsic mechanism that regulates hematopoietic cell fate decisions is the ubiquitin proteasome system (UPS). The UPS controls protein levels by tagging them with polyubiquitin chains and promoting their degradation through the proteasome. The key component of the UPS is the ubiquitin E3 ligase as this protein is the …

Novel Mechanisms Of Protein Kinase C Α Regulation And Function, Xinyue Li

Theses & Dissertations

Protein kinase Cα (PKCα) is a member of the PKC family of serine/threonine kinases, which have been implicated in regulation of many cellular processes, including cell proliferation, differentiation, survival, and transformation. A large body of evidence from the Black laboratory and others support an anti-proliferative function of PKCα in normal epithelial tissues, including the intestinal mucosa and endometrial epithelium. PKCα is also tumor suppressive in epithelial cancers, such as colorectal cancer (CRC) and endometrial cancer (EC). However, a major obstacle to harnessing the tumor suppressive functions of PKCα to benefit patients is the widespread loss of PKCα expression in tumors. …

Investigating The Role Of Splenic Macrophages In Pancreatic Cancer, Daisy V. Gonzalez

Theses & Dissertations

Pancreatic cancer is currently the 3rd leading cause of all cancer-related deaths, with a 5-year survival rate remaining at 10%. The current standard treatment of care and a lack of effective diagnostic markers leaves patients with a dismal prognosis at advanced stages of the disease. This thesis research evaluated the effect of ApoE-expressing macrophages in the spleen. First, we aimed to assess the ApoE expression in the spleen of pancreatic tumor-bearing mice. Results showed that ApoE expression in splenic macrophages increased as the disease progressed. In addition, we saw a significant increase in marginal zone metallophilic macrophages and red pulp …

Post-Transcriptional Control Of The Epithelial-To-Mesenchymal Transition (Emt) In Ras-Driven Colorectal Cancers, Chaitra Rao

Theses & Dissertations

Colorectal cancer (CRC) originates from epithelial cells lining the colon or rectum of the gastrointestinal tract. Most cancer deaths result from a tumor spreading to distant organs; however epithelial cells do not normally migrate from their tissue of origin. To do so, epithelial cells undergo biochemical changes allowing them to acquire behavior similar to motile mesenchymal cells termed the epithelial-to-mesenchymal transition (EMT), which contributes to tumor invasion and metastasis. Our study demonstrated that CRC cells require a molecular scaffold, Kinase Suppressor of Ras 1 (KSR1), and ERK to promote the EMT-like phenotype through the preferential translation of Epithelial Stromal Interaction …

Dysregulation Of Mir-10a Promotes Cancer Features In Cholangiocarcinoma, Matthieu Spriet

Theses & Dissertations

Cholangiocarcinoma is a primary liver cancer of the bile duct epithelium that exhibits microRNA-mediated control of tumor cell signaling. Strides toward new treatment rest on a better defining of cholangiocarcinoma tumor biology including the RNA-based layer of regulation. Additionally, there is a gap in knowledge on microRNA expression in human tissue. While there is RNA-seq data of microRNA expression in tissue, it does not differentiate between cell types, thus leaving unanswered questions about cell specific microRNA biology and expression.

Here, we identify miR-10a as an oncogenic microRNA acting through MAPK signaling. Using cholangiocarcinoma cell lines, we determined miR-10a is an …

Aberrant Age-Related Alterations In Spontaneous Cortical Activity In Participants With Cerebral Palsy, Hannah Bergwell

Theses & Dissertations

Cerebral Palsy (CP) is the most common neurodevelopmental motor disability, resulting in life-long sensory, perception and motor impairments. These impairments appear to drastically worsen with advancing age within the CP population, although the underlying neuro-physiological mechanisms remain poorly understood. Herein, we began to address this knowledge gap by utilizing magnetoencephalographic (MEG) to study how aging impacts the amplitude of spontaneous brain activity (i.e., resting state) in a cohort of 38 individuals with spastic diplegic CP (Age = 22.08 ± 10.46 years) and 67 neurotypical controls (NT) (Age = 19.56 ± 10.25 years). Participants completed an eyes-closed resting-state paradigm while undergoing …

Sox2 Dosage Governs Tumor Cell Identity And Proliferation, Ethan P. Metz

Theses & Dissertations

The stem cell transcription factor SOX2 has been widely recognized for its critical roles during mammalian development. SOX2 expression has also been implicated in more than 20 types of human cancers. Importantly, the expression of SOX2 is regulated at multiple levels, which enables the tight regulation of SOX2 levels. Previous work from our laboratory has shown that elevating SOX2 from an inducible promoter inhibits the proliferation of several human tumor cell types. Other studies have reported that high levels of SOX2 are necessary to maintain lineage plasticity in advanced tumors. Thus, the dosage of SOX2 plays a critical role in …

Evaluating Targets And Therapeutics For The Treatment Of Pancreatic Cancer, Shelby M. Knoche

Theses & Dissertations

Pancreatic cancer has a dismally low survival rate, due to inadequate understanding of the processes that are involved in disease development and progression. Despite the identification of oncogenic drivers such as KRAS and p53, there is a need for the identification of molecular targets to improve and develop novel therapeutic approaches for the treatment of pancreatic cancer. Studies from our laboratory have identified and evaluated targets and therapeutic approaches that can aid in our understanding of pancreatic cancer disease progression and improve patient outcomes. Through the use of epidermal growth factor receptor (EGFR) ligands (EGF and TGF-α) and small molecule …

Characterization Of 1,1-Diarylethylene Foxm1 Inhibitors Against High-Grade Serous Ovarian Carcinoma Cells, Cassie Liu

Theses & Dissertations

Forkhead box M1 (FOXM1) is a member of the conserved forkhead box (FOX) transcription factor family. Over the last two decades, FOXM1 has emerged as a multifunctional oncoprotein and a robust biomarker of poor prognosis in many human malignancies. FOXM1 and its associated oncogenic transcriptional signature are enriched in >85% of ovarian cancer cases, and FOXM1 expression and activity can be enhanced by a plethora of genomic, transcriptional, post-transcriptional, and post-translational mechanisms. As a master transcriptional regulator, FOXM1 promotes critical oncogenic phenotypes in ovarian cancer, including: (1) cell proliferation, (2) invasion and metastasis, (3) chemotherapy resistance, (4) cancer stem cell …

Mechanisms Of Sorting And Fission At The Endosomes, Kanika Dhawan

Theses & Dissertations

Endocytic trafficking is a fundamental cellular process that regulates the transport of lipids and proteins. Our lab focuses on the intracellular trafficking of receptors involved in cellular processes such as cell division, migration, and proliferation. Accordingly, the regulation of these trafficking pathways is tightly controlled, involving a complex series of events, of which a key step is the endosomal fission. Perturbations in the endosomal network can eventually lead to impaired receptor recycling to the plasma membrane (PM) and, therefore, have pathological consequences like Alzheimer’s disease and multiple cancers. Upon internalization, cargo-laden vesicles released from the PM fuse with the sorting …

Visceral Adipose Tissue Remodeling In Pancreatic Ductal Adenocarcinoma Cachexia: The Role Of Activin A Signaling, Pauline Xu

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer death in the United States and is projected to become the second leading cause by the year 2030. Prognosis for patients with metastatic disease remains dismal, with cachexia as a main contributor to the low survival rate. Emerging reports indicate that PDAC patients display distinct phenotypes of cachexia development, with either adipose tissue loss preceding skeletal muscle wasting or loss of only adipose tissue. While muscle wasting has been the most frequently studied mechanism in cachexia research, changes in adipose tissue are increasingly understood as important components of …

Innate Immunity In The Pathobiology And Treatment Of Infectious And Neurodegenerative Diseases, Mai Mostafa

Theses & Dissertations

Mononuclear phagocytes (MPs; monocytes, macrophages, and dendritic cells) are the governors of innate immunity which is the body’s first line of defense against microbial pathogens. They act beneficial or detrimental. They are crucial for an effective non-specific immune response to invading pathogens by engulfing, destroying, then eliciting an adaptive specific immune response. Given their pivotal functions in the host immune defense, studying MP immune responses in disease is paramount important for understanding disease pathobiology and uncovering therapeutic strategies.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the driver of acute respiratory distress syndrome (ARDS) in coronavirus disease 2019 (COVID-19) amongst …

Psychological Trauma Alters T-Lymphocyte Inflammation And Redox Through Sympathetic Mechanisms, Safwan K. Elkhatib

Theses & Dissertations

Posttraumatic stress disorder (PTSD) is a devastating psychiatric disorder characterized by distinctive symptom clusters, including intrusive memories (i.e., flashbacks), avoidance of related stimuli, affective changes, and hyperarousal. Strikingly, patients with PTSD face a significantly increased risk for a number of inflammation-driven pathologies, ranging from cardiovascular to autoimmune disease. Yet, the exact etiology of this increased risk remains unknown. The immune system is known to be strongly influenced by the sympathetic nervous system, and sympathetic overactivity is a hallmark of PTSD. Lymphoid organs, such as the spleen, are richly innervated by sympathetic nerve fibers which terminate near adaptive immune …

Exploring Host-Pathogen Interactions Of The Ebola Virus Ribonucleoprotein Complex, M. Jane Morwitzer

Theses & Dissertations

Ebola virus (EBOV) causes a severe hemorrhagic fever in humans that is oftentimes lethal, emerging as a global public health threat in recent years. Understanding the host factors that contribute to the dynamic states and functions of the EBOV ribonucleoprotein (RNP) complex could potentially advance the development of therapeutics. The viral architecture of the EBOV RNP complex has been defined but host protein interactions that modulate viral replication have largely gone unaddressed. EBOV nucleoprotein (NP) and viral protein 35 (VP35) play critical roles in viral replication and capsid assembly, comprising two major components of the RNP complex. Elucidation of host …

Astrocytic Contribution To Sensory Hypersensitivity In A Mouse Model Of Fragile X Syndrome, Lara E. Bergdolt

Theses & Dissertations

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and a leading cause of autism spectrum disorder (ASD). FXS is caused by mutations in the fragile X mental retardation gene (FMR1), which result in complete or substantial loss of expression of its protein product fragile X mental retardation protein (FMRP). Neuronal impairments in the absence of FMRP have been extensively characterized. However, much less is known about the impact that loss of FMRP has on the physiology and function of astrocytes and the implications for behavior. A common behavior exhibited by both FXS and ASD patients …

Linking Spinal Cord Circuits With Upper Limb Sensorimotor Control In Adults With Cerebral Palsy, Saihari Dukkipati

Theses & Dissertations

Cerebral palsy (CP) is the most common neurological disorder originating in childhood, but most of the people living with CP are currently adults. While people with CP continue to get older, the amount of research focused on adults has been rather limited. The early childhood insults leading to CP are thought to originate in the brain, but the effects on the entire neuromuscular system across the lifespan have only recently started to be explored. Of note, recent neuroimaging evidence suggests that the cervical spinal cord structure is atypical in adults with CP. However, it is largely unclear how the neurophysiological …

Use Of Machine Learning Algorithms And Highly Multiplexed Immunohistochemistry To Perform In-Depth Characterization Of Primary Pancreatic Tumors And Metastatic Sites, Krysten Vance

Theses & Dissertations

Pancreatic cancer is currently the third leading cause of cancer death and projected to be the second by 2030. Metastatic pancreatic cancer, the most common form of the disease, has a dismal 3% five-year survival rate. However, understanding of the metastatic disease and particularly the metastatic tumor microenvironment (TME), which includes all non-cancerous cells in and around the tumor, has remained limited. The well-documented impact of the TME on cancer cell proliferation, chemoresistance, and patient survival in the primary tumors, indicates that the study of the microenvironment in metastatic cancer is integral to treating advanced patients. To better comprehend this …

Targeting Androgen Receptor On Glioblastoma, Nan Zhao

Theses & Dissertations

Glioblastoma (GBM) is the most aggressive primary brain malignancy. The standard treatment of this tumor is surgery, followed by radiation with concurrent and adjuvant temozolomide. GBM cancer stem cells (CSCs) have been proposed to be responsible for radioresistance. It is necessary to identify novel therapeutic agent(s) that can pass the blood-brain barrier (BBB) and enhance radiation effects. Targeting the androgen receptor (AR) is promising in treating glioblastoma (GBM) in cell culture, and flank implant models but the mechanisms remain unclear. AR antagonists, including enzalutamide, are available for treating prostate cancer patients in the clinic and can pass the BBB; thus, …

Polymeric Nanocarriers For Delivery Of Small Molecules Inhibiting Tubulin Polymerization For The Treatment Of Pancreatic Cancer And Lung Metastatic Melanoma, Rajan Sharma Bhattarai

Theses & Dissertations

The aim of this thesis is to develop delivery systems for the novel small molecules which inhibit tubulin polymerization. One of the small molecules was modified to lipid conjugate to increase the lipophilicity of the molecules which in turn drastically improved the drug loading in amphiphilic polymeric system. The second molecule was conjugated to the amphiphilic polymeric backbone with pH sensitive Schiff’s linker for the tumor site specific delivery in lung metastatic melanoma model.

Chapter 1 discusses the tumor microenvironment for the solid tumor especially focusing on Pancreatic Ductal Adenocarcinoma (PDAC). Further the drug delivery system currently researched for addressing …

Determining The Role Of Mir-133a In The Diabetic Heart, Tyler Kambis

Theses & Dissertations

Diabetes mellitus (DM) is characterized by hyperglycemia, hyperlipidemia, and hypoinsulemia, each of which disrupt intracellular mechanisms in the heart. DM is a chronic metabolic disease delineated into two categories: insulin deficient-type 1 DM and insulin resistant-type 2 DM. Although they differ in underlying genetic and physiological factors, both significantly increase the risk of heart failure. Impaired insulin signaling shifts energy dependency from glycolysis towards fatty acid β-oxidation in the DM heart. This DM-induced metabolic shift increases mitochondrial stress leading to mitochondrial dysfunction and cell death in the heart. The metabolically entwined ferroptosis is a novel form of myocardial cell death …

Phos-Tag-Based Screens Identify Novel Therapeutic Targets In Ovarian Cancer And Pancreatic Cancer, Renya Zeng

Theses & Dissertations

Multiple Phos-tag-based screens were conducted in anti-tubulin drug (paclitaxel and nocodazole)-treated cells to explore novel targets implicated in cell cycle regulation, resistance against paclitaxel, and yes-associated protein (YAP) nucleocytoplasmic transport. The Phos-tag-based screen of protein kinases identified that several proteins were degraded or phosphorylated in response to anti-tubulin drug treatment. A tyrosine kinase, fibroblast growth factor receptor 4 (FGFR4), was significantly degraded upon anti-tubulin drug treatment, suggesting its potential role in cell response to paclitaxel. Further functional investigations identified that FGFR4 mediated paclitaxel resistance in ovarian cancer, and specific inhibitors targeting FGFR4 could sensitize ovarian cancer cells to paclitaxel. Mechanistically, …

Paf1/Pd2 Augments Pancreatic Cancer Progression And Mediates Radiation And Chemoresistance, Sanchita Rauth

Theses & Dissertations

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Frailty And Neurocognition In Prostate Cancer, Lindsey Hanson

Theses & Dissertations

Prostate cancer (PCa) treatment often leads to distressing side effects ranging from muscle loss, physical inactivity, and fatigue to cancer associated cognitive decline (CACD). Evidence suggests that men treated with androgen deprivation therapy (ADT) may have a specifically high risk of CACD, partially due to increased frailty. However, the current literature on cognitive effects of ADT is equivocal. Therefore, the primary objectives of this study were to (1) compare cognitive function, physical activity (PA), and fitness in men receiving ADT, men scheduled to receive radiation, and men under active surveillance for PCa; (2) examine changes in cognitive performance and PA …

The Role Of Calprotectin In T-Lymphocyte Driven Inflammation In A Mouse Model Of Psychological Trauma, Cassandra Moshfegh

Theses & Dissertations

Post-traumatic stress disorder (PTSD) is a debilitating psychological disorder that affects nearly 45 million Americans. This mental disorder is characterized by behavioral symptoms such as learned helplessness, hyperarousal, withdrawal, and flashbacks. The deleterious effects of PTSD are far-reaching and go beyond behavioral dysfunction, as these individuals are at a three-fold higher risk of comorbid inflammatory diseases. Autonomic, metabolic, and cardiovascular diseases plague these individuals later in their lifetime, however, the mechanistic link connecting psychological trauma to this systemic peripheral immunological dysfunction remains elusive. T-lymphocyte-induced inflammation plays a significant role in all these disease pathologies. Previous work from our laboratory demonstrated …