Medicine and Health Sciences Commons^™

Studies On The Leukocyte-Associated Ig-Like Inhibitory Receptor-1 Signaling Pathway In T Lymphocytes, Chidi Zacheaus

Theses and Dissertations (ETD)

Inflammation is a natural process in which the immune system concertedly responds to pathogens and abnormal cell growth to protect the host. For an efficient/effective immune response that circumvents tissue atrophy, a delicate balance between stimulatory and inhibitory mechanisms is essential for the proper functioning of the immune system. Immuno-receptor Tyrosine-based Inhibitory Motif (ITIM)-bearing receptors in immune cells, including T lymphocytes, play a major role in preventing autoimmune responses. Leukocyte-associated Ig-like Inhibitory Receptor 1 (LAIR-1) is one of ITIM-bearing receptors. The mechanism by which LAIR-1 attenuates T-cell response has yet to be completely understood. In this study, I investigated a …

The Role And Immunogenicity Of Cbfa2t3-Glis2 In Pediatric Acute Megakaryoblastic Leukemia, Elizabeth A. Garfinkle

Theses and Dissertations (ETD)

CBFA2T3-GLIS2 is the most prevalent fusion oncogene in pediatric acute megakaryoblastic leukemia in patients without Down syndrome (non-DS-AMKL) and is associated with an event free survival of only 8% even with high intensity chemotherapy and stem cell transplant in first remission. A cryptic inversion event on chromosome 16 joins the three nervy homology regions (NHR) of CBFA2T3 to the five zinc fingers of GLIS2. This configuration enables the encoded chimeric transcription factor to bind GLIS consensus sequences throughout the genome and recruit transcriptional activators and repressors to alter gene expression and enhance self-renewal capability. Few cooperating mutations have been identified …

Identifying The Molecular Cause Of Extreme Endoplasmic Reticulum Dilation In Pediatric Osteosarcoma And Its Relationship To The Disease, Rachael Wood

Theses and Dissertations (ETD)

Pediatric osteosarcoma tumors are characterized by an unusual abundance of grossly dilated endoplasmic reticulum and an immense genomic instability that has complicated identifying new effective molecular therapeutic targets. Here we report a novel molecular signature that encompasses the majority of 108 patient tumor samples, PDXs and osteosarcoma cell lines. These tumors exhibit reduced expression of four critical COPII vesicle proteins that has resulted in the accumulation of procollagen-I protein within ‘hallmark’ dilated ER. Using CRISPR activation technology, increased expression of only SAR1A and SEC24D to physiologically normal levels was sufficient to restore both collagen-I secretion and resolve dilated ER morphology …

The Molecular Mechanisms Of Estrogen Receptor Α On Two Single Nucleotide Polymorphisms To Regulate Wnt Signaling In Osteoblasts, Sarocha Suthon

Theses and Dissertations (ETD)

Osteoporosis is the most common bone metabolic disorder, affecting over 200 million people globally. It is characterized by bone mass depletion and microarchitectural deterioration, leading to bone fragility and susceptibility to bone fracture. Genetic factors, estrogen deficiency, and dysregulation of the WNT signaling pathway contribute to the development of this disease. Genome-wide association studies have predicted that the single nucleotide polymorphisms (SNPs) rs2887571 and rs9921222 associate with low bone mass, but the mechanism of these SNPs has remained unknown. Analysis of osteoblasts from 112 different joint replacement patients reveals that the genotype of rs2887571 correlates with WNT5B expression, and the …

Genomic Characterization Of Sickle Cell Mouse Models For Therapeutic Genome Editing Applications, Kaitly Jensen Woodard

Theses and Dissertations (ETD)

Sickle cell disease (SCD) is caused by a mutation of the β-globin gene (HBB), resulting in abnormal hemoglobin molecules that polymerize when deoxygenated, forming “sickle” shaped red blood cells (RBCs). Sickle RBCs lead to anemia, multi-organ damage and pain crises, beginning the first year of life. The onset of symptoms coincides with the developmental switch of β-like globin gene expression from fetal stage γ-globin to adult stage β-globin, resulting in a shift from fetal hemoglobin (HbF, α2γ2) to adult hemoglobin (HbA, α2β2). Some individuals harbor rare genetic variants in the extended β-globin gene cluster that cause constitutively elevated postnatal HbF, …

The Heme-Regulated Inhibitor Pathway Modulates Susceptibility Of Poor Prognosis B-Lineage Acute Leukemia To Bh3-Mimetics, Kaitlyn Hill Smith

Theses and Dissertations (ETD)

Anti-apoptotic MCL1 is one of the most frequently amplified genes in human cancers and its elevated expression confers resistance to many therapeutics including the BH3-mimetic agents ABT-199 and ABT-263. The anti-malarial, dihydroartemisinin (DHA) translationally represses MCL-1 and synergizes with BH3-mimetics. To explore how DHA represses MCL-1, a genome-wide CRISPR screen identified that loss of genes in the heme synthesis pathway renders mouse BCR-ABL+ B-ALL cells resistant to DHA-induced death. Mechanistically, DHA disrupts the interaction between heme and the eIF2α kinase heme regulated inhibitor (HRI) triggering the integrated stress response. Genetic ablation of Eif2ak1, which encodes HRI, blocks MCL-1 repression in …

Therapeutic Potential Of Trp Channels In The Targeting Of Rheumatoid Arthritis Synovial Fibroblasts, Brittany Isabella Schwam

Theses and Dissertations (ETD)

Rheumatoid arthritis is a chronic inflammatory disease primarily affecting the synovium, articular cartilage, and bone within a joint, but it is a unique form of arthritis wherein effects are systemic. The cause of this autoimmune disease remains unknown, but there are many environmental and genetic factors that play into susceptibility. Research is still far from drug-free remission despite great advancements over the past few decades. The majority of therapies developed rely on immunosuppressant or immunomodulator molecules and come with risk of infection, high costs, and toxic, uncontrolled side effects. Those diagnosed maintain a significant unmet need for targeted therapies.

There …

Delineating The Mechanisms Of Misfolded Endoplasmic Reticulum (Er) Luminal Protein Retrotranslocation For Er-Associated Degradation, Christina Oikonomou

Theses and Dissertations (ETD)

Secreted, plasma membrane, and resident proteins of the secretory pathway are synthesized in the endoplasmic reticulum (ER) where they undergo post-translational modifications, oxidative folding, and subunit assembly in tightly monitored processes. An ER quality control (ERQC) system oversees protein maturation and ensures that only those reaching their native state will continue trafficking into the secretory pathway to reach their final destinations. Proteins that fail quality control must be recognized and eliminated to maintain ER proteostasis. The ER-associated degradation (ERAD) was discovered nearly 30 years ago and entails the identification of improperly matured secretory pathway proteins and their retrotranslocation to the …

Transcriptional Regulation Of Nlrc4 Inflammasome By Irf8, Ein Lee

Theses and Dissertations (ETD)

The NLRC4 inflammasome is a crucial part of the innate immune response against bacterial infections. We found that NLRC4 inflammasome activation in bone marrow-derived macrophages (BMDMs) is greatly dependent on interferon regulatory factor 8 (IRF8). NLRC4-mediated caspase-1 activation and subsequent production of the inflammasome-dependent cytokines IL-1β and IL-18 and cell death were impaired in IRF8-deficient cells. IRF8 mediated the transcription of genes encoding NAIPs, the receptors for NLRC4 inflammasome, which recognize bacterial flagellin and type III secretion system (T3SS) proteins. IRF8 was critical for host survival following infection with Salmonella Typhimurium or Burkholderia thailandensis. Furthermore, mice deficient in IRF8 were …

Targeting The Colchicine Binding Site On Tubulin To Overcome Multidrug Resistance And Anticancer Efficacy Of Selective Survivin Inhibitors, Kinsle E. Arnst

Theses and Dissertations (ETD)

Tubulin inhibitors are widely used as chemotherapeutic agents, and their successis attributed to their ability to target microtubule dynamics and disrupt critical cellular functions including cell signaling, motility, intracellular trafficking, and mitosis. Interference with microtubule dynamics consequently disrupts mitotic progression and ultimately leads to apoptosis, validating microtubule dynamics as an excellent target for anticancer agents. While this class of drug has proven to be effective against many cancer types, the clinical efficacy of current tubulin inhibitors is often limited by the development of multidrug resistance. The most common form of resistance to these agents arises from the overexpression of drug …

The Role Of Exosomal Transport Of Viral Agents In Persistent Hiv Pathogenesis, Benjamin J. Patters

Theses and Dissertations (ETD)

Human immunodeficiency virus (HIV) infection, despite great advances in antiretroviral therapy (ART), remains a lifelong affliction. Though current treatment regimens can effectively suppress viral load to undetectable levels and preserve healthy immune function, they cannot fully alleviate all symptoms caused by the presence of the virus, such as HIV-associated neurocognitive disorders (HAND). Exosomes are small vesicles that transport cellular proteins, RNA, and small molecules between cells as a mechanism of intercellular communication. Recent research has shown that HIV proteins and RNA can be packaged into exosomes and transported between cells, to pathogenic effect. This review summarizes the current knowledge on …

The Role Of Bip Co-Chaperone Sil1 In Marinesco-Sjögren Syndrome Pathogenesis, Viraj Paresh Ichhaporia

Theses and Dissertations (ETD)

Marinesco-Sjögren syndrome (MSS) is a rare, autosomal recessive, multisystem disorder, which is characterized by cerebellar ataxia, early-onset bilateral cataracts, and progressive myopathy amongst other symptoms. MSS has been attributed to mutations in the SIL1 gene, which encodes a nucleotide exchange factor for the endoplasmicreticulum- resident Hsp70 chaperone, BiP. To date, there are 46 MSS-associated mutations that have been reported in SIL1, which occur throughout this gene and are predicted to result in a loss of SIL1’s function. The large majority of these mutations cause deletions of large fractions of the SIL1 protein. Nine MSS-associated mutations are particularly interesting because they …

Molecular Interplay Of Chromatin Remodeling Factor Brg1 And Transcription Factor Stat3 Regulates Stemness, Chemosensitivity And Tumorigenicity Of Glioma Tumor Initiating Cells, Debolina Ganguly

Theses and Dissertations (ETD)

Glioblastoma Multiforme (GBM) is an aggressive brain tumor, characterized by high cellular heterogeneity, is refractory to treatment and has dismal prognosis. These characteristics of GBM have suggested the presence of stem-like cells that have the ability to initiate and maintain tumors of a heterogeneous nature, and bestow resistance to current therapeutic regimens. It is therefore imperative to identify the dysregulated molecular pathways which enable the maintenance of these cells in a stem-like state in order to inform strategies to therapeutically target them.

In this study, we investigated the role of the Y705 and S727 phosphorylation domains of STAT3, a multifunctional …

Role Of Smarce1 And Bhlhe40 In Breast Cancer Metastasis, Aarti Sethuraman

Theses and Dissertations (ETD)

No abstract provided.

Somatic Mutation Detection In Leukemia-Derived Circulating Dna: Utility In Monitoring Clonal Dynamics And Disease Response In Pediatric Acute Lymphoblastic Leukemia, Sarah Hisham Abdelaziz Youssef

Theses and Dissertations (ETD)

Despite the improved outcome associated with current treatment strategies ofpediatric acute lymphoblastic leukemia (ALL), relapse still represents a major challenge. Pediatric ALL demonstrates branched evolution in response to selective pressure exerted by therapy; relapse founder clones emerge from pre-leukemic clones or minor subclones present at diagnosis. It is hence crucial to develop biomarkers capable of tracking subclones throughout therapy. Current practices for monitoring disease response in leukemia rely on the analysis of BM biopsy sample at specific time points throughout therapy. Not only the invasiveness of the BM biopsy hinders the sequential sampling, but also, the currently implied techniques are …

Genome-Scale Precision Proteomics Identifies Cancer Signaling Networks And Therapeutic Vulnerabilities, Hong Wang

Theses and Dissertations (ETD)

Mass spectrometry (MS) based-proteomics technology has been emerging as an indispensable tool for biomedical research. But the highly diverse physical and chemical properties of the protein building blocks and the dramatic human proteome complexity largely limited proteomic profiling depth. Moreover, there was a lack of high-throughput quantitative strategies that were both precise and parallel to in-depth proteomic techniques. To solve these grand challenges, a high resolution liquid chromatography (LC) system that coupled with an advanced mass spectrometer was developed to allow genome-scale human proteome identification. Using the combination of pre-MS peptide fractionation, MS2-based interference detection and post-MS computational interference correction, …

Role Of Dendritic Cells In Pathology Of Respiratory Syncytial Virus Infection In Neonates, Bishwas Shrestha

Theses and Dissertations (ETD)

Respiratory syncytial virus (RSV) is one of the leading causes of bronchiolitis in children. We have shown that neonatal mice respond to primary RSV infection with T helper type 2 (Th2) biased immune responses, which are enhanced following reinfection. Dendritic cells (DCs) including myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) play important roles in driving host responses to RSV infection. mDCs present antigens to help Th cells differentiate, and pDCs protect against viral infection through type I interferons (IFNs). Despite data demonstrating importance of mDCs and pDCs in protection against RSV, it has not been studied in an age appropriate …

Investigating The Regulation And Function Of The Nr4a Nuclear Receptors In Cancer, Jordan A. Beard

Theses and Dissertations (ETD)

The nuclear receptor (NR) superfamily represents a structurally-conserved group of ligand-regulated transcription factors. These proteins have critical roles in various physiological and pathological processes, including cancer, and have been targets of drug therapy. The orphan NR subfamily 4A (NR4A), which includes the NR4A1 (Nur77), NR4A2 (Nurr1), and NR4A3 (Nor-1) genes, has been implicated in adult solid tumors and has been characterized as pro-tumorigenic mediator of cell proliferation, transformation, migration, and drug resistance. Alternatively, in leukemia, NR4A1 and NR4A3 have been described as tumor suppressors in hematologic malignancies. Members of the NR4A family are commonly overexpressed in cancer and this has …

Reprogramming To Pluripotency Using Small Molecule Compounds, Brittany E. Greenberg

Theses and Dissertations (ETD)

The generation of induced pluripotent stem cells (iPSCs) through the use of small molecule compounds has evolved as a potential cellular reprogramming strategy. Individually, specific small molecule compounds have previously been shown to replace reprogramming transcription factors or enhance the efficiency of cellular reprogramming. More recently, a combination of small molecule compounds can replace all of the reprogramming factors. In this review, we describe in detail the generation of chemically induced pluripotent stem cells using small molecule inhibitors and activators that target either downstream protein kinases or modify chromatin structure to promote somatic cell reprogramming. In addition, epigenetic modulating small …

Molecular Mechanisms Underlying Alcohol-Induced Cerebral Artery Smooth Muscle Bk Channel Inhibition And Eventual Cerebral Vasoconstriction, Guruprasad Kuntamallappanavar

Theses and Dissertations (ETD)

Introduction and Rationale: Ethanol (EtOH) at concentrations obtained in circulation during moderate to heavy episodic drinking, such as during binge drinking (30-60 mM) causes cerebral vasoconstriction in many species, including humans. Using rodents as a model to study ethanolinduced cerebral artery constriction, our laboratory demonstrated that ethanol-induced cerebral artery constriction is due to drug-induced reduction of STOCs (Spontaneous Transient Outward Currents) in cerebral artery smooth muscle. In this tissue, STOCs result from the activity of large conductance, calcium-and voltage-gated potassium (BK) channels. Indeed, ethanol (50 mM) decreases the steady-state activity (NPo) of vascular myocyte BK channels leading to an increase …

Downregulation Of Prdm16 Is Critical For Hoxb4-Mediated Benign Hsc Expansion In Vivo, Hui Yu

Theses and Dissertations (ETD)

Overexpression of HOXB4 in hematopoietic stem cells (HSCs) leads to increased self-renewal without causing hematopoietic malignancies in transplanted mice. The molecular basis of HOXB4-mediated benign HSC expansion in vivo is not well understood. To gain further insight into the molecular events underlying HOXB4-mediated HSC expansion, we analyzed gene expression changes at multiple time points in Lin-Sca1+c-kit+ (LSK) cells from mice transplanted with bone marrow (BM) cells transduced with a MSCV-HOXB4-ires-YFP vector. A distinct HOXB4 transcriptional program was reproducibly induced and stabilized by 12 weeks after transplant. Dynamic expression changes were observed in genes critical for HSC self- renewal as well …

Characterization Of Cre Mouse Models To Target Cns Barriers For Generating Conditional Knockouts Of Abc Transporters, Rachel L. Scheib

Theses and Dissertations (ETD)

The central nervous system (CNS) includes the brain and spinal cord, where both possess a blood to brain and a blood to cerebrospinal fluid (CSF) barrier. The blood-brain barrier (BBB) and blood-CSF barrier (BCSFB) regulate the passage of many molecules to maintain and protect these sensitive organs from harmful xenobiotics (i.e. drugs, pollutants, etc.) or physiologic changes (i.e. glucose, ion, or water composition). These barriers also express ABC transporters, including P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP), which are known to contribute to efflux of endogenous toxins and therapeutics from the CNS. Pgp and BCRP expression and activity are …

Molecular Characterization Of Glioblastoma Cancer Stem Cells, Jo Meagan Garner

Theses and Dissertations (ETD)

Malignant gliomas are locally aggressive, highly vascular tumors that have an overall survival time less than 14 months, and current therapies provide little improvement in the disease course and outcome. While glioblastoma multiforme (GBM) patients present uniform histological phenotypes, the molecular determinants of the disease vary considerably between individual cases resulting in complicated prognosis. The heterogeneity, aggressiveness and rapid tumor relapse of GBM is believed to be sustained by cancer stem-like cell populations that are able to initiate and maintain tumors. Although CSCs represent only a small fraction of cells within a tumor, their high tumor-initiating capacity and therapeutic resistance …

Adenylyl Cyclase 2 Selectively Regulates Il-6 Expression In Human Bronchial Smooth Muscle Cells, Amy Sue Bogard

Theses and Dissertations (ETD)

Adenylyl cyclase (AC) catalyzes the formation of the ubiquitous second messenger cAMP. AC isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions, and most cells express multiple isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses. Overexpression of individual isoforms had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes in human bronchial smooth muscle cells (BSMC) and human embryonic kidney cells (HEK-293). Most notable, in BSMC overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production …

Regulation Of Secretory Phospholipase A2 By Thyroid Hormone, Pragya Sharma

Theses and Dissertations (ETD)

Rationale: Low grade inflammation has been correlated with elevated risk of hepatic steatosis and atherosclerosis. Secretory phospholipase A2 group IIA (PLA2g2a) enhances the progression of several chronic inflammatory diseases including arthritis and atherosclerosis. The potential linkage of hypothyroidism with inflammation led us to examine the modulation of sPLA2 expression by thyroid hormone (T3) in liver.

Objective: Most of the studies of phospholipase A2 group IIA (PLA2g2a) have been conducted with macrophages and vascular smooth muscle cells with regard to atherosclerosis. The liver is one of the major contributors to the total pool of extracellular PLA2g2a. The aim of the present …

Metabotropic Glutamate Receptor 5 In The Medial Prefrontal Cortex: Role In Cocaine Sensitization And Addiction, Kristin Marie Timmer

Theses and Dissertations (ETD)

Cocaine sensitization is associated with cocaine-induced hyperexcitability of pyramidal projection neurons within the medial prefrontal cortex (mPFC). Such hyperexcitability presumably results in increased glutamatergic input to reward-affiliated brain regions such as the ventral tegemental area (VTA) and nucleus accumbens (NAc), consequently facilitating drugseeking behavior. Metabotropic glutamate receptor 5 (mGluR5) has been implicated in cocaine addiction and demonstrated to increase neuronal excitability, therefore, the aim of the present study was to investigate the effect of intra-mPFC mGluR5 manipulation on behavioral and neurochemical sensitization and drug-seeking. Bilateral cannulae were implanted into the mPFC of male Sprague-Dawley rats and mGluR5 antagonist MTEP (15 …

Cns Penetration Of Tyrosine Kinase Inhibitors In Mouse Models, Mohamed Elmeliegy

Theses and Dissertations (ETD)

For the past three decades, advances in the treatment of central nervous system (CNS) tumors such as malignant glioma have only been modest. One particular challenge facing treatment of brain tumors is the delivery of therapeutically effective concentrations of anti-cancer agents to the target site in the brain. The sanctuary of the brain is protected by several barrier systems such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). These barriers restrict the passage of anti-cancer drugs into the brain via several protective mechanisms.

In the present study, we used cerebral microdialysis sampling, a technique for sampling unbound …

The Molecular Basis Of Fitness And Transmissibility Of Neuraminidase Inhibitor Resistant Influenza A Viruses, Susu Duan

Theses and Dissertations (ETD)

Neuraminidase (NA) inhibitors including oral oseltamivir and inhaled zanamivir are among the first line of defense against influenza virus infection. Development of resistance to NA inhibitors is a huge drawback for limited options for the control of influenza. During the first decade of NA inhibitor use, the detection rates of resistance to both NA inhibitors had remained low in circulating influenza viruses. However, the 2008~2009 season was marked by a radical increase of prevalence of oseltamvir resistance from <1% to >90% in worldwide surveillance in less than a year. The resistance was solely linked to NA H275Y variants of seasonal H1N1 viruses, …

Hp Turns 17: T Helper 17 Cell Response During Hypersensitivity Pneumonitis (Hp) And Factors Controlling It, Hossam Abdelsamed

Theses and Dissertations (ETD)

Hypersensitivity Pneumonitis (HP) is an interstitial lung disease caused by repeated inhalation of a wide range of environmental antigens. It is characterized by alveolitis, granuloma formation, and fibrosis. Since HP is a T cell-mediated disease, it is important to determine the type of T cell response associated with granuloma formation and the factors that control this response. We hypothesized that HP is associated with a predominant Th17 cell response where both T-bet and TLRs 2 and 9 are controlling T cell response during HP. The results demonstrated a predominant Th17 response associated with granuloma formation in the lungs of C57BL/6J …

Testing Whether Mrp4 (A Camp Efflux Pump) And The Beta 2 Andrenergic Receptor (An Upstream Regulator Of Camp Signaling Pathways, Praveen Kumar Potukuchi

Theses and Dissertations (ETD)

Background and Aim: MRP4/ABCC4 is an ABC transporter that can efflux the second-messenger, cAMP, from cells. MRP4 has a PDZ interacting motif at its carboxy terminal end through which it binds to scaffolding proteins NHERF1 and PDZK1. Previous studies have shown that PDZK1 serves as a scaffold physically coupling MRP4 with the cystic fibrosis transmembrane conductance regulator (CFTR). This protein complex functionally couples cAMP regulation of CFTR function with MRP4 cAMP transporter activity [Li, C., et al., Spatiotemporal coupling of cAMP transporter to CFTR chloride channel function in the gut epithelia. Cell, 2007. 131(5): p. 940-51]. We hypothesized that the …