Endocytic Trafficking Of The Amyloid Precursor Protein In Rat Cortical Neurons, Sahily Reyes

Dissertations and Theses (Open Access)

Amyloid-beta (Aβ) aggregation and deposition into extracellular plaques is a hallmark of the most common forms of dementia, including Alzheimer’s disease. The Aβ-containing plaques result from pathogenic cleavage of amyloid precursor protein (APP) by secretases resulting in intracellular production of Aβ peptides that are secreted and accumulate extracellularly. Despite considerable progress towards understanding APP processing and Aβ aggregation, the mechanisms underlying endosomal production of Aβ peptides and their secretion remain unclear. Using endosomes isolated from cultured primary neurons, we determined that the trafficking of APP from the endosomal membrane into internal vesicles of late endosome/multivesicular bodies (MVB) is dependent on …

Membrane Bound Il21 Promotes Natural Killer Cell Expansion Through Mir 124-3p Mediated Regulation, Anitha Somanchi

Dissertations and Theses (Open Access)

Natural Killer (NK) cells are cells of the innate immune system that act as first line of defense against viral infections and participate in tumor immune surveillance. NK cells do not cause graft versus host disease (GvHD), or require prior antigen exposure to exert anti-tumor activity, hence are an attractive choice for immunotherapy applications. Owing to small numbers of NK cells in peripheral blood (1-32%, with a 6% median), ex vivo expansion of NK cells is critical for NK cell adoptive immunotherapy, various expansion platforms have been explored over the decades. We developed a robust platform for ex vivo expansion …

Increased Habenular Connectivity In Opioid Users Is Associated With An Α5 Subunit Nicotinic Receptor Genetic Variant, Kaylah Curtis, Humsini Viswanath, Kenia M Velasquez, David L Molfese, Mark J Harding, Eduardo Aramayo, Philip R Baldwin, Elisa Ambrosi, Alok Madan, Michelle Patriquin, B Christopher Frueh, J Christopher Fowler, Thomas R Kosten, David A Nielsen, Ramiro Salas

Staff and Researcher Publications

Background and objectives: Opioid use disorder (OUD) is a chronic disorder with relapse based on both desire for reinforcement (craving) and avoidance of withdrawal. The aversive aspect of dependence and relapse has been associated with a small brain structure called the habenula, which expresses large numbers of both opioid and nicotinic receptors. Additionally, opioid withdrawal symptoms can be induced in opioid-treated rodents by blocking not only opioid, but also nicotinic receptors. This receptor co-localization and cross-induction of withdrawal therefore might lead to genetic variation in the nicotinic receptor influencing development of human opioid dependence through its impact on the aversive …

Effects Of Once-Weekly Exenatide On Cardiovascular Outcomes In Type 2 Diabetes, Rury R Holman, M Angelyn Bethel, Robert J Mentz, Vivian P Thompson, Yuliya Lokhnygina, John B Buse, Juliana C Chan, Jasmine Choi, Stephanie M Gustavson, Nayyar Iqbal, Aldo P Maggioni, Steven P Marso, Peter Öhman, Neha J Pagidipati, Neil Poulter, Ambady Ramachandran, Bernard Zinman, Adrian F Hernandez

Faculty, Staff and Student Publications

BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown.

METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy.

RESULTS: …

Impact Of Vitamin A And Carotenoids On The Risk Of Tuberculosis Progression, Omowunmi Aibana, Molly F Franke, Chuan-Chin Huang, Jerome T Galea, Roger Calderon, Zibiao Zhang, Mercedes C Becerra, Emily R Smith, Alayne G Ronnenberg, Carmen Contreras, Rosa Yataco, Leonid Lecca, Megan B Murray

Faculty, Staff and Student Publications

BACKGROUND: Low and deficient levels of vitamin A are common in low- and middle-income countries where tuberculosis burden is high. We assessed the impact of baseline levels of vitamin A and carotenoids on tuberculosis disease risk.

METHODS: We conducted a case-control study nested within a longitudinal cohort of household contacts (HHCs) of pulmonary tuberculosis case patients in Lima, Peru. We defined case patients as human immunodeficiency virus (HIV)-negative HHCs with blood samples in whom tuberculosis disease developed ≥15 days after enrollment of the index patient. For each case patient, we randomly selected 4 controls from among contacts in whom tuberculosis …

Wisp1 Is An Overexpressed Driver Of Glioblastoma, Pushan R. Dasgupta

Dissertations and Theses (Open Access)

Despite current multimodal therapies for glioblastoma (GBM) the prognosis remains very grim. There is a tremendous need to identify new genetic drivers which can serve as potential therapeutic targets. In order to find new drivers, we leveraged genomic datasets to conduct a context specific in vivo functional genomic screen of overexpressed and/or amplified genes in GBM. We identified WISP1, a secreted extracellular matrix protein, to be an overexpressed driver in GBM. Overexpression of WISP1 was able to drive tumor growth in various in vivo models. Knockdown of WISP1 with shRNAs resulted in reduced colony formation in vitro and reduced tumor …

Identifying The Immune Related Metabolic Properties Of Pancreatic Cancer Using Nuclear Magnetic Resonance Spectroscopy And Dynamic Magnetic Resonance Spectroscopic Imaging With Hyperpolarized Pyruvate, Joseph Weygand

Dissertations and Theses (Open Access)

Despite its relatively low incidence, pancreatic cancer was the fourth leading cause of cancer-related death in the US in 2015. This is due in part to pancreatic cancer’s natural resistance to both chemotherapy and radiotherapy. Immunotherapy presents an attractive potential treatment approach, but initial trials in mice have proved ineffective. Because cancer cells exhibit a significant increase in metabolic activity relative to normal tissue, an understanding of the metabolic function of tumors in systems with different levels of immunocompetence is a critical first step to develop an understanding of the immune-related metabolic properties of the tumor, which have potential application …

Clinical And Therapeutic Significance Of Obesity In Melanoma, Jennifer L. Mcquade

Dissertations and Theses (Open Access)

While the FDA approval of targeted and immune therapies in metastatic melanoma (MM) have dramatically improved outcomes in this disease, de novo and/or acquired resistance can limit the clinical benefit of these agents. The IGF-1/PI3K/AKT pathway has been implicated in resistance to both targeted and immune therapy. The IGF-1/PI3K/AKT pathway has also been shown to play a key role in the pathogenesis of obesity in other malignancies. To date, the impact of energy balance on clinical outcomes and therapeutic response in MM has not been studied. I hypothesized that energy balance would impact the molecular biology, behavior, and drug sensitivity …

Optogenetic Interrogation Of Primary Visual Cortex And Its Impact On Neural Coding And Behavior, Ariana R. Andrei

Dissertations and Theses (Open Access)

Understanding the mechanism by which the brain transforms simple sensory inputs into rich perceptual experiences is one of the great mysteries of systems neuroscience. Undoubtedly this involves the activity of large populations of interconnected neurons, but while the responses of individual neurons to a variety of sensory stimuli have been well-characterized, how populations of such neurons organize their activity to create our sensory perceptions is almost entirely unknown. To investigate this complex circuitry requires the ability to causally manipulate the activity of neural populations and monitor the resultant effects. Here we focus on primary visual cortex (V1), which has been …

Involvement Of The Receptor For Advanced Glycation End Products (Rage) In Progression Of Pancreatic Cancer, Nancy Azizian Ms

Dissertations and Theses (Open Access)

Oncogenic KRAS is central to several cancer types including pancreatic ductal adenocarcinoma (PDAC), but has been determined to be “undruggable”. Recent studies have indicated that oncogenic KRAS is not constitutively active but relies on a feed-forward stimulatory mechanism involving inflammation. In the current study we investigated the mechanisms by which, the receptor for advanced glycation end products (RAGE) affects and maintains KRAS activity. We observed that RAGE levels were elevated and there was a shift in the levels of specific isoforms upon inflammation in pancreatic cells and PDAC. Furthermore, RAGE agonists were found to increase Ras activity and downstream signaling …

The Role Of The Epithelial-To-Mesenchymal Transition (Emt) In Lung Cancer Progression, David H. Peng

Dissertations and Theses (Open Access)

Lung cancer is the leading cause of cancer-related deaths due to conventional therapy resistance and metastatic disease, therefore understanding the mechanisms governing these biological functions is vital for improving patient survival. Approximately 30% of patients with the adenocarcinoma histologic subset of lung cancer possess an activating KRAS mutation, characterized by a lack of response to chemotherapies with a poor overall 5-year survival rate. Despite the mutational frequency, KRAS remains a challenge to pharmacologically inhibit and current drugs undergoing clinical trials that target specific downstream effector proteins of KRAS, such as MEK inhibitors, have failed to produce significant clinical benefits. Previous …

Contrasting Effects Of An Mdm2 Functional Polymorphism On Tumor Phenotypes, Guadalupe J. Ortiz Iv

Dissertations and Theses (Open Access)

Cancer predisposition by the cooperation of genetic variants, such as single nucleotide polymorphisms (SNPs), may be of much greater significance to public health than previously appreciated. Functional polymorphisms are genetic variants that alter gene function. Meta-analyses associate many functional polymorphisms with cancer risk. The MDM2 SNP309G allele is a cancer-associated functional polymorphism positioned in the MDM2 P2 promoter that enhances transcription factor SP1 binding, resulting in elevated levels of MDM2 concomitant with decreased p53 tumor-suppressor activity. Mdm2^SNP309G/G mice are more prone to spontaneous tumor formation than Mdm2^SNP309T/T mice, providing direct evidence for the impact of this SNP on …

Improving Nk Cell Therapy For Osteosarcoma, Jennifer Foltz

Dissertations and Theses (Open Access)

Osteosarcoma (OS) is the most common primary bone tumor. Despite new treatment options, 5-year survival for metastatic OS has remained at only 30% for the last 30 years. Adoptive transfer of Natural Killer (NK) cells holds promise for a new, non-toxic therapy for OS. NK cells are part of the innate immune system and readily kill metastatic and chemotherapy-resistant OS in vitro and in murine models. However, there is little data regarding their efficacy in animal models with an intact immune system. In addition, the OS tumor microenvironment is highly suppressive, producing TGFβ which impedes NK cell killing of solid …

Preclinical Development Of Therapeutic Strategies Against Triple-Negative And Inflammatory Breast Cancer, Angie M. Torres-Adorno

Dissertations and Theses (Open Access)

Triple-negative (TNBC) and inflammatory (IBC) breast cancer are the most aggressive forms of breast cancer, accounting for 20% and 10% of cancer-related deaths, respectively. Among IBC cases, 30% are additionally classified with TNBC molecular pathology, a diagnosis that significantly worsens patient’s prognosis. The current lack of TNBC and IBC molecular understanding prevents the development of effective therapeutic strategies. To identify effective treatments, we explored aberrant apoptosis pathways and cell membrane fluidity as novel therapeutic targets.

We first identified an effective therapeutic strategy against TNBC and IBC by pro-apoptotic protein NOXA-mediated inhibition of the anti-apoptotic protein MCL1 following inhibition of histone …

Investigating The Role Of Prmt1 And Arginine Methylation Of Hsp70 In Human Pancreatic Cancer, Liang Wang

Dissertations and Theses (Open Access)

Protein arginine methyltransferase 1 (PRMT1) is the major arginine methyltransferase, which catalyzes the addition of one or two methyl groups to the arginine residues of its substrate proteins. The best-known substrate for PRMT1 is histone, while more and more non-histone proteins are now found to be methylated by PRMT1. Dysregulation of PRMT1 is reported in several human cancer types. However, its biological roles in human pancreatic cancer initiation and development are still unclear. In the first part of this study, I found that the expression level of PRMT1 was elevated in both human and mouse pancreatic cancer tissues in immunohistochemistry …

Improvements In Four-Dimensional And Dual Energy Computed To Mography, Rachael M. Martin

Dissertations and Theses (Open Access)

Dual energy and 4D computed tomography (CT) seek to address some of the limitations in traditional CT imaging. Dual energy CT, among other purposes, allows for the quantification and improved visualization of contrast materials, and 4D CT is often used in radiation therapy applications as it allows for the visualization and quantification of object motion. While much research has been done with these technologies, areas remain for potential improvement, both in preclinical and clinical settings, which will be explored in this dissertation. Preclinical dual energy cone-beam CT (CBCT) can benefit from wider separation between the peak energy of the two …

Modification Of Aplysia Feeding Network By L-Dopa And Dopamine-Dependent Learning, Curtis Neveu, Curtis L. Neveu

Dissertations and Theses (Open Access)

Dopamine (DA) is a ubiquitous neuromodulator of neuronal networks in the animal kingdom and has a well-established role in modulating motor behavior and encoding reward information. Although the effects of DA and DA-dependent learning at the behavioral and molecular levels are well-understood, many questions still remain concerning the effects of DA at the network level. DA-dependent learning effects on a neuronal circuit were examined by measuring the biophysical properties before and after in vitro operant conditioning (OC) of the feeding circuit of Aplysia. OC reduced the excitability of B4 and the B4-to-B51 synaptic connection, with a trend towards an …

Pharmacologic And Genetic Manipulations Of Angiotensin Signaling In Thoracic Aortic Disease Models, Andrew M. Peters

Dissertations and Theses (Open Access)

Thoracic aortic aneurysms and dissections (TAAD) are a major cause of morbidity and mortality in patients. Many different risk factors have been associated TAAD, but hypertension is the largest risk factor. Subsets of TAAD patients have identifiable syndromic genetic diseases, yet a number of genetic non-syndromic patients have been identified. Infusion of angiotensin II into mouse models causes aortic disease through inflammation and fibrosis. An angiotensin type I receptor (AT1R) blocker (ARB) or an angiotensin converting enzyme (ACE) inhibitor (ACEi) can reverse aortic pathology in some mouse models. I set out to better understand the relationship between angiotensin and TAAD …

A Novel Bioinformatic Approach To Understanding Addiction, Latifa F. Jackson

Journal of Family Strengths

Finding the genetic markers that influence complex, multigenic substance addiction phenotypes has been an area of significant medical study. Understanding complex disease traits like addiction has been hampered by the lack of functional insights into novel variants to the human genome. We hypothesized that gene location plays a role in functional genomic neighborhoods.

To test whether there is a relationship between opiate, dopamine, and GABA disease and population allele frequencies, we used genes obtained from addiction literature curated by the National Center for Biotechnology Information (NCBI). These addiction and metabolism focused search terms generated opiate, dopamine, and GABA addiction results …

The External Globus Pallidus: Bidirectional Control Over Anxiety-Related Behavior Mediated By Crfr1, Albert J. Hunt Jr

Dissertations and Theses (Open Access)

Abstract

THE EXTERNAL GLOBUS PALLIDUS: BIDIRECTIONAL CONTROL OVER ANXIETY-RELATED BEHAVIOR MEDIATED BY CRFR1

Albert Lee Joseph Hunt, Jr., B.S.

Advisory Professor: Shane Cunha, Ph.D.

Corticotropin-releasing factor receptor 1 (CRFR1), the principle receptor responsible for the anxiogenic activity of the stress peptide CRF, is abundantly expressed in the external globus pallidus (GPe) raising the question whether activity in the GPe is altered in response to stress. I show that CRFR1 expressing neurons are of the “prototypic” subtype of GPe neurons. I provide evidence of novel circuits from CRF neurons in stress-responsive nuclei, including the paraventricular nucleus of the hypothalamus (PVN) and …

Visualizing The Dynamics Of Immune Surveillance In Brain Tumors By Intravital Multiphoton Microscopy, Felix Nwajei

Dissertations and Theses (Open Access)

Visualizing the dynamics of immune surveillance in brain tumors by intravital multiphoton microscopy

By

Felix I. Nwajei, MD

Supervisory Professor: Tomasz Zal, Ph.D.

Brain tumors (BTs) generally have a bad prognosis despite conventional treatment strategies. Immunotherapy is a relatively novel treatment approach that has shown benefit for durable treatment of melanoma, and is a promising candidate for different tumor types including BTs. Immunotherapeutic strategies work by exploiting and/or enhancing natural anti-tumor immune response, a process that is critically dependent on adaptive immunity, T cell infiltration and surveillance of tumor. However, little is known about the dynamics and regulation of T …

Parp Inhibitor Upregulates Pd-L1 Expression And Enhances Cancer-Associated Immunosuppression, Shiping Jiao

Dissertations and Theses (Open Access)

With recent approvals for therapeutic antibodies that block CTLA4, PD-1 and PD-L1, immune checkpoints have emerged as new targets in cancer therapy. In addition, there is accumulating evidence highlighting the role of cancer-associated immunity in patient response to cytotoxic anticancer agents. Inhibitors of poly (ADP-ribose) polymerase (PARP) have shown substantial cytotoxic effects against tumors with defects in DNA damage responses. However, whether a crosstalk between PARP inhibition and immune checkpoints exists remains unclear. Here, it has been shown that PARP inhibitors (PARPis) upregulate PD-L1 expression in multiple cancer cell lines, human xenograft tumors, and syngeneic mouse tumors. Mechanistically, PARPi inactivates …

The Hypoxic Adenosine Response Modulates Macrophage Differentiation And Contributes To Lung Disease, Kemly Mary Philip

Dissertations and Theses (Open Access)

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease which affects 5 - 8 million individuals worldwide and 200,000 individuals in the United States alone. Although prevalent, we do not know what causes IPF and no effective curative treatment exists for this disease. Our laboratory has shown that extracellular accumulation of adenosine and subsequent activation of the adenosine 2B (ADORA2B) receptor promotes immune cell invasion, airspace destruction, and fibrosis in chronic lung disease. Additionally, alternatively activated alveolar macrophages (AAMs) expressing ADORA2B, have been implicated in mediating adenosine’s pro-fibrotic effects in IPF. However, the exact role of AAMs in the hypoxic …

Role And Regulation Of Sphingosine 1-Phosphate In Erythrocyte, Kaiqi Sun

Dissertations and Theses (Open Access)

Sphingosine 1-phosphate (S1P) is a bioactive signaling sphingolipid produced in every mammalian cell. It plays a variety of important roles both in and outside of cells. S1P is highly enriched in mature erythrocytes because of the high enzymatic activity of the S1P-generating enzyme Sphingosine Kinase 1 (Sphk1) and the absence of S1P degrading enzymes. Erythrocytes are considered only a major reservoir for S1P because they supply S1P to the circulation for the regulation of various physiological processes which include but are not limited to immune cell trafficking, endothelial integrity and hematopoietic stem cell mobilization. However, if S1P plays a role …

Integrative Analysis Of Omics Data In Adult Glioma And Other Tcga Cancers To Guide Precision Medicine, Xin Hu, Xin Hu

Dissertations and Theses (Open Access)

Transcriptomic profiling and gene expression signatures have been widely applied as effective approaches for enhancing the molecular classification, diagnosis, prognosis or prediction of therapeutic response towards personalized therapy for cancer patients. Thanks to modern genome-wide profiling technology, scientists are able to build engines leveraging massive genomic variations and integrating with clinical data to identify “at risk” individuals for the sake of prevention, diagnosis and therapeutic interventions. In my graduate work for my Ph.D. thesis, I have investigated genomic sequencing data mining to comprehensively characterise molecular classifications and aberrant genomic events associated with clinical prognosis and treatment response, through applying high-dimensional …

Tumor-Cell Derived Inhibin, Beta A Is Essential For Adrenergic Effects On Fibroblast Activation, Archana Sidalaghatta Nagaraja

Dissertations and Theses (Open Access)

Objectives: Catecholamine-mediated effects driven by elevated adrenergic signaling are known to increase tumor growth and metastasis by direct effects on tumor cells. However, knowledge of effects of adrenergic signaling on other cells such as cancer-associated fibroblasts (CAFs) within the tumor microenvironment is limited. We hypothesize that adrenergic signaling and norepinephrine can accelerate the induction of CAF-phenotype to promote inflammation and metastasis.

Methods: Ingenuity Pathway Analysis and NetWalker were used to assess gene expression data from patients with known CESD (Center for Epidemiological Studies-Depression)-score alongside microdissected CAFs from primary ovarian cancer. Tumor samples from mice exposed to daily restraint-stress or non-stressed …

The Role Of The Diras Family Members In Regulating Ras Function, Cancer Growth And Autophagy, Margie Nicole Sutton

Dissertations and Theses (Open Access)

DIRAS3 is a maternally imprinted tumor suppressor gene that is downregulated by multiple mechanisms across several tumor types. When re-expressed, DIRAS3 decreases proliferation, inhibits motility, and induces autophagy and tumor dormancy. DIRAS3 encodes a 26 kDa small GTPase with 60% homology to Ras and Rap, differing from oncogenic Ras family members by a 34-amino acid N-terminal extension that is required for its tumor suppressive function in ovarian cancer. By assessing the structure-function relationship, I found that DIRAS3 inhibits Ras-induced transformation and is a natural antagonist of Ras/MAPK signaling. DIRAS3 binds directly to Ras and disrupts cluster formation inhibiting the activation …

Androgen Receptor And Prostate Cancer Cell Heterogeneity, Qu Deng

Dissertations and Theses (Open Access)

Androgen receptor (AR) plays an important role in prostate cancer (PCa) development and has been the main therapeutic target in advanced PCa. AR expression is heterogeneous in both primary PCa and castration resistant prostate cancer (CRPC). However, the functional significance of AR heterogeneity in regulating PCa biology and response to androgen/AR-targeted therapies remains unclear. The overarching hypothesis for my Ph.D is that AR heterogeneity contributes to PCa development, progression, and therapy resistance. A more specific postulate is that PCa cells expressing AR (i.e, AR⁺) and PCa cells expressing little AR (i.e, AR^-/lo) possess intrinsically distinct …

Characterization And Reversal Of Doxorubicin-Mediated Changes In Sensory Neurons, Brittany L. Coughlin

Dissertations and Theses (Open Access)

Chemotherapeutic agents impair memory in humans as well as in animal models. Such memory impairments can be persistent, lasting years after exposure to chemotherapy. Doxorubicin (DOX), a common chemotherapeutic agent, has been associated with memory impairments in humans and induces memory deficits in rodent models. DOX also impairs serotonin (5-HT)-induced long-term synaptic facilitation (LTF) in Aplysia sensorimotor co-cultures, a cellular analog of long-term memory formation. In addition, DOX leads to dynamic activation of extracellular signal-regulated kinase (ERK), consisting of an immediate and a delayed phase of activation, and to transient activation of p38 mitogen-activated protein kinase (p38 MAPK) in Aplysia …

Evaluating The Impact Of Post-Translational Modifications By The Secreted Zinc Metalloprotease, Gele, On The Major Autolysin Of E. Faecalis, Atla, And A Stress-Induced Protein, Salb, Emily K. Stinemetz

Dissertations and Theses (Open Access)

AtlA is the major peptidoglycan hydrolase of E. faecalis involved in cell separation of dividing cells. SalB is a secreted stress-induced protein regulated by the CroRS system. In addition, these two proteins also appear to be affected by the virulence factor, gelatinase (GelE). GelE is a secreted zinc metalloprotease known to impact various cellular functions by post- translational modification of protein substrates. The overall objective of this work was to understand how GelE cleavage of secreted proteins, specifically AtlA and SalB, changes their function. Herein, I discovered that GelE modifies both AtlA and SalB. As visualized by Western blot analysis …