Digital Commons Network^™

Aberrant Astrocyte Maturation Contributes To Rett Syndrome Pathogenesis, Natasha Lynn Pacheco

All ETDs from UAB

Rett syndrome (RTT) is caused by mutations in the gene encoding the transcriptional modulator, Methyl-CpG-Binding Protein 2 (MeCP2). RTT is characterized by motor, behavioral and physiological deficits. MECP2 mutations are associated with other disorders such as autism, schizophrenia, and intellectual disability, underscoring the important role of MeCP2 for typical brain function. Much of our understanding of MeCP2 function is derived from transcriptomic studies carried out over the last 10 years with the general assumption that alterations in the transcriptome correlate with proteomic changes. Advances in mass spectrometry-based proteomics have facilitated recent interest in the examination of global protein expression. In …

The Role Of Astrocytes In The Development Of Central Chemosensitivity, Kelsey Patterson

All ETDs from UAB

In the two decades since MECP2 was identified as the causative gene in the majority of Rett Syndrome (RTT) cases, transgenic mouse models have played a critical role in our understanding of this X-linked neurodevelopmental disease. However, their exclusive use presents a limitation in translating findings from animal models to the clinic. Here, we characterized growth, anatomical, behavioral, and motor deficits in a novel zinc-finger nuclease murine RTT model from birth through adulthood. Male rats lacking the transcriptional regulatory protein, MeCP2 (Mecp2ZFN/y), are noticeably symptomatic as early as postnatal day (P) 21 and die prematurely, while females lacking one copy …

The Role Of Pim Kinases In Hepatoblastoma Tumorigenicity, Stem Cell-Like Cancer Cell Maintenance, And Chemoresistance, Laura Lee Stafman

All ETDs from UAB

Hepatoblastoma is the most common primary liver malignancy in children. Despite increasing incidence, treatment has not changed significantly in the past 20 years, making the need for novel therapeutics imperative. Proviral Integration site for Moloney murine leukemia virus (PIM) kinases are a family of serine/threonine kinases that have been implicated in multiple other cancer types including the adult liver cancer, hepatocellular carcinoma. Emerging evidence has begun to elucidate a role for PIM kinases in stem-cell like cancer cells (SCLCCs). This subpopulation of cells is thought tobe responsible for tumor maintenance, recurrence, metastasis, and chemoresistance. Chemoresistance is a significant barrier to …

The Role Of Glycosylation Initiation By Galnac-Ts In Iga Nephropathy, Tyler Stewart

All ETDs from UAB

The autoimmune disease IgA nephropathy (IgAN) is a common cause of primary glo-merulonephritis, often resulting in end-stage renal disease. IgAN patients have elevated serum levels of immunoglobulin A1 (IgA1) with autoantigenic galactose-deficient (gd) O-glycans. The gd-O-glycans occur at specific sites within IgA1 hinge-region. We hy-pothesized that GalNAc-Ts play a role in the formation of gd-IgA1, due to their role in determining glycosylation sites and densities. To better understand how GalNAc-Ts may change O-glycans of IgA1 in IgAN we characterized the complex glycosylation mecha-nism involved in mucin-type O-glycan synthesis of IgA1 hinge-region. In the first section of this work, we explore …

Protein O-Glcnacylation In Hippocampal Hyperexcitability & Gabaergic Neurotransmission, Luke Thomas Stewart

All ETDs from UAB

Plasticity at central synapses is a vital component of neuronal function and an intensively studied phenomenon thought to underlie learning and memory processes in brain structures including the hippocampus and cerebral cortex. A principle mechanism at work during long-term plasticity is the rapid and heavily regulated post-translational modification of synaptic proteins such as phosphorylation and ubiquitination. A comparatively understudied modification is ‘O-GlcNAcylation’, a distinct form of monoglycosylation with rapid intracellular signaling capacity as opposed to the structural and extracellular signaling roles of O- and N-linked polysaccharide chains on conventionally glycosylated proteins. O-GlcNAcylated proteins are found in every cell type/tissue system …

Pharmacological Inhibition Of Thioredoxin-Interacting Protein To Protect Against Diabetes, Lance Thielen

All ETDs from UAB

The loss of functional beta cell mass represents a major factor in the pathogenesis of type 1 and type 2 diabetes. Inadequate production of insulin, a glucose-lowering hormone, and elevated glucagon production, a gluconeogenic hormone, contribute to impaired glycemic control and hyperglycemia. This promotes a vicious cycle involving glucotoxicity and additional beta cell dysfunction. Currently there are no therapies that halt this process; however, thioredoxin-interacting protein (TXNIP) has recently emerged as a promising therapeutic target. TXNIP was found to be the top glucose-induced gene in a human pancreatic islet microarray, is increased in mouse models of diabetes and diabetic human …

The Oxidative Tyrosine Modification, O,O’-Dityrosine, In Lung Disease, Morgan Locy

All ETDs from UAB

The oxidative tyrosine modification, o,o′-dityrosine, has been identified in various pathologic conditions associated with oxidative stress in mammalian systems, and demonstrated to be important in physiologic processes in invertebrate organisms. The formation of o,o’-dityrosine is catalyzed by a heme peroxidase (hPx) in the presence of hydrogen peroxide (H2O2). The understanding of this stable, covalent tyrosine modifica-tion in lung biology is limited. Oxidative stress has been implicated in the pathogenesis of various lung diseases, including interstitial lung disease (ILD) and cystic fibrosis (CF). We observed that the oxidative protein modification, o,o’-dityrosine, was markedly ele-vated in the circulating plasma of ILD patients …

Role Of Mycobacterium Avium Paratuberculosis (Map) And Tnfsf15 Snps On Tl1a In Cd, Sayf Al-Deen Hassouneh

Electronic Theses and Dissertations

Tumor Necrosis Factor-Like Ligand 1a (TL1A) is a cytokine encoded by Tumor Necrosis Factor Super Family 15 gene (TNFSF15) gene mostly in endothelial cells which binds to T-cells and foments the production of pro-inflammatory cytokines including TNF-α, IL-6, IL-1b, IFN- γ and IL-13. TL1A level is elevated in inflammatory diseases including Crohn's Disease (CD). Although Single Nucleotide Polymorphisms (SNPs) in TNFSF15 have been reported in CD, no studies have investigated the effect of these SNPs on TL1A, inflammation, and susceptibility to Mycobacterium avium subspecies paratuberculosis (MAP) infection. MAP is a strong candidate in CD pathogenesis. This study is designed to …

Exacerbation Of Δefp Sickness In Escherichia Coli By An Uncharacterized Rna Helicase, Robert Wingo

Electronic Theses and Dissertations

In Escherichia coli, growth is rate-limited by translation capacity [1]. Stalled ribosomes have profound effects on a cell such as altered mRNA abundance, decreased ribosome availability, and an imbalanced proteome. The absence of elongation factor P (EF-P), a universally conserved transpeptidation enhancer, presents an extreme example of this scenario, wherein ribosomes accumulate disproportionately onto messages that are more slowly translated and cell growth becomes notably impaired. We discovered that faster-growing cells arise spontaneously in Δefp cultures, suggesting that translation defects could be circumvented by mutating other genes. This thesis presents a genetic and biochemical analysis of a mechanism Δefp cells …

The Evaluation Of Mefloquine Drug Repurposing On Acute Myeloid Leukemia, Jessica L. Phan, Bhavuk Garg, Hrishikesh Mehta, Seth Corey

UROP Posters

The aim of this study is to observe cell proliferation, cell viability, apoptosis, and autophagy on acute myeloid leukemia (AML) cell lines, NB4 and U937, with the drug repurposing of mefloquine (MQ). Methods such as the 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay and trypan blue staining have shown a decrease in live cells with high concentrations of mefloquine. Using their average perspective IC50 values of MQ concentration, Western blotting was applied by means of apoptosis and autophagy markers to determine if the induction of apoptosis and inhibition of autophagy was present in MQ-treated AML cells. The experiment will be continued with more …

The Effect Of Dna Methylation On Tp73 Expression In Tumorgenesis, Nujuma A. Moussa

UROP Posters

Abstract: The Effect of DNA Methylation on TP73 Expression in Tumorgenesis

Nujuma Moussa, Zhixing Yao, Zaki A. Sherif

Department of Biochemistry & Molecular Biology, Howard University College of Medicine

TP73 is a member of the TP53 family of proteins that acts as a transcription factor to help regulate cellular distress. This tumor protein may play a dual role as a tumor suppressor and tumor promoter. The TP73 gene is mapped to chromosome 1p36, a frequently deleted region in neuroblastoma and other types of tumors. While mutations in the TP53 gene are commonly known to cause noxious cancers, 30% of cancers …

Cone Phosphodiesterase-6Γ’ Subunit Augments Cone Pde6 Holoenzyme Assembly And Stability In A Mouse Model Lacking Both Rod And Cone Pde6 Catalytic Subunits, Wen-Tao Deng, Saravanan Kolandaivelu, Astra Dinculescu, Jie Li, Ping Zhu, Vince A. Chiodo, Visvanathan Ramamurthy, William W. Hauswirth

Faculty & Staff Scholarship

Rod and cone phosphodiesterase 6 (PDE6) are key effector enzymes of the vertebrate phototransduction pathway. Rod PDE6 consists of two catalytic subunits PDE6α and PDE6β and two identical inhibitory PDE6γ subunits, while cone PDE6 is composed of two identical PDE6α’ catalytic subunits and two identical cone-specific PDE6γ’ inhibitory subunits. Despite their prominent function in regulating cGMP levels and therefore rod and cone light response properties, it is not known how each subunit contributes to the functional differences between rods and cones. In this study, we generated an rd10/cpfl1 mouse model lacking rod PDE6β and cone PDE6α’ subunits. Both rod and …

Use Of Memantine In Autism Spectrum Disorder: A Case Report, Adam Schindzielorz Md, Kristina Bryant-Melvin Md, Suzanne Holroyd Md, Kelly Melvin Md

Psychiatry

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder of varying severity and phenotypic expression that is characterized by persistent deficits in social relatedness, communication skills, and interfering repetitive behaviors. Associated behavioral pathology can include inattention, aggression, irritability, hyperactivity, anxiety, and self-injury. Currently, FDAapproved treatments exist to treat secondary symptoms but not core symptomatology. The etiology of autism and other ASD is thought to be multifactorial but is not well understood. Some studies suggest that glutamate excitotoxicity may play a role in the pathogenesis of ASD. Memantine, an NMDAreceptor antagonist, could potentially address core symptoms in ASD by targeting disease-specific pathophysiology. …

Functional Analysis Of Cdc45 In The Replication Fork And In Response To Replicative Stress, Amanda Debrot

All ETDs from UAB

DNA replication is a highly conserved and tightly regulated process, with a variety of factors acting to ensure faithful duplication and stability of chromosomal DNA. During replication, positive supercoils form ahead of the advancing replication fork. DNA topoisomerase 1 (Top1) acts to prevent DNA damage by relieving the torsional strain created by these supercoils. The camptothecin (CPT) class of chemotherapeutics target Top1, creating a long-lived DNA-Top1-CPT covalent complex, which leads to S-phase specific DNA lesions and cellular death. Our lab previously performed a genetic screen to isolate mutant proteins that enhance cell sensitivity to Top1-mediated DNA damage. One of the …

The Primary Cilium Regulates Interstitial Immune Cells During Renal Cystogenesis, Cheng Song

All ETDs from UAB

Renal cysts are a pathological condition that can lead to end-stage renal failure and death. The mechanisms that underlie renal cyst development are under active investigation, and emerging evidence has revealed defects in a number of proteins required for cilia assembly or signaling, such as intraflagellar transport (IFT) proteins and the polycystins. Characterization of mice harboring conditional IFT mutations suggests that the rate of cyst formation is dependent upon the timing of cilia loss. Induction of cilia loss in juvenile mice results in rapid cyst development, while induction of cilia loss in adult mice leads to a slower progressing form …

Analysis Of The Gtp Cyclohydrolase I/Tetrahydrobiopterin Pathway In Glioblastoma Biology, Anh Tran

All ETDs from UAB

Glioblastomas (GBMs) are the most common primary malignant brain tumors in adults and one of the most aggressive cancers with high rates of recurrence and therapeutic resistance. In GBMs, subpopulations of highly tumorigenic cells called brain tumor initiating cells (BTICs) have the unique capacity to promote tumor maintenance, therapeutic resistance, and angiogenesis. Depending on the level, differentiation state, and tumor stage, reactive nitrogen and oxygen species inhibit or increase cancer growth and BTIC maintenance. GTP cyclohydrolase 1 (GCH1) is the rate limiting enzyme in a pathway that can regulate reactive species production but has not been thoroughly investigated in GBM. …

Global Analysis Of Rpl12 Epistasis Within The Yor1-Δf Biogenesis Network, Mert Icyuz

All ETDs from UAB

In frame deletion of the phenylalanine residue at position 508 of the cystic fibrosis transmembrane conductance regulator (CFTR-ΔF508) results in protein misfolding and degradation, which reduces expression and function at the plasma membrane. The resulting loss of chloride and bicarbonate transport is the molecular basis of cystic fibrosis (CF). The F508-analogous mutation in the yeast oligomycin resistance 1 gene, yor1-ΔF670, has the same molecular consequences, but the phenotypic consequence is reduced resistance to growth inhibition by oligomycin. Comprehensive, systematic and quantitative analysis Yor1-ΔF gene modifiers has been demonstrated as a powerful way to further characterize known and to discover novel …

Evaluating Fty720 As An Anticancer Agent In Models Of Ovarian Cancer, Kelly Marie Kreitzburg

All ETDs from UAB

Despite satisfactory initial responses to frontline therapies that combine tumor debulking with platinum and taxane-based chemotherapies, ovarian cancer remains the principle cause of gynecological malignancies. Drug resistance at relapse contributes to poor outcomes for women diagnosed with advanced disease and underscores the need for novel therapeutic strategies. Compelling data have implicated bioactive sphingolipids and their metabolism in the development and progression of ovarian cancer. Aberrations in sphingolipid metabolism that limit levels of the tumor suppressor lipid ceramide contribute to chemotherapy resistance. This dissertation presents work investigating the anticancer efficacy of the immunomodulatory drug FTY720. The sphingosine analog FTY720 has shown …

An Investigation Of Sla Class Ii As A Xenoantigen, Joseph Ladowski

All ETDs from UAB

Xenotransplantation, using genetically-modified pigs as organ donors, is a potential solution to the growing transplant organ shortage. Avoiding antibody-mediated rejection (AMR) is the remaining hurdle to widespread application. The development of a triple glycan knockout pig reduced antibody binding to clinically acceptable levels, allowing for the screening of the history of antibodies to the major histocompatibility complex (MHC). In allotransplantation, the MHC is a group of proteins divided into two classes and anti-MHC antibodies possess the ability to cause both acute and chronic AMR. The pig MHC, the swine leukocyte antigen (SLA), is a hypothesized target of antibodies. This dissertation …

Genetic Influences On Rheumatoid Arthritis In Global Populations, Vincent Albert Laufer

All ETDs from UAB

Rheumatoid arthritis (RA) is a complex disease having numerous genetic and environmental risk factors the interplay of which produces RA pathobiology. While the sheer number of genetic and environmental risk factors complicates understanding of disease biology, understanding has progressed far enough for insight into the most likely mechanisms for the development of the disease. Modern studies of the genetics of RA are massively parallel, enabling researchers to systematically interrogate variants throughout the human genome for associations in genome-wide association studies or GWAS. Such studies have been carried out in European and Asian cohorts many times, and the most recent RA …

The Mechanism Of Tobacco-Induced Decrements In Mucociliary Clearance, Vivian Lin

All ETDs from UAB

Chronic obstructive pulmonary disease (COPD), characterized by progressive loss of lung function including mucus obstruction and airway remodeling, is primarily caused by cigarette smoking. This pulmonary phenotype resembles that of cystic fibrosis (CF), which results from genetic mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), an ion channel important in maintaining airway surface hydration and mucus clearance. Cigarette smoke exposure has been found to induce acquired CFTR dysfunction, leading to airway dehydration, abnormal mucin production, and impaired mucus transport. Smoke exposure also induces mucus hypersecretion and ciliary dysfunction; together, these changes result in defective mucus clearance and subsequent muco-obstruction. …

T Cell Immunity Directed Against Novel Anti-Sense Cryptic Epitopes And Its Impact On Hiv Viral Evolution, Binghao Jason Peng

All ETDs from UAB

After nearly four decades of scientific research, a global solution in eradicating the human immunodeficiency virus - 1 (HIV-1) pandemic has still yet to be discovered. The advent of antiretroviral therapies (ART) has significantly decreased the diseases burden for those infected with the virus; however, the access to ART is often limited to those with the financial abilities to afford it. For this reason, finding a way to vaccinate against HIV-1 successfully remains a sought-after pragmatic solution to this worldwide health issue. HIV immunological studies have taught us that increasing the breadth of response to the virus holds significant potential …

Mucus Adhesion As A Therapeutic Target In Cystic Fibrosis, Courtney Fernandez Petty

All ETDs from UAB

Cystic fibrosis (CF) is a genetic disease resulting from mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CFTR is an ion channel responsible for proper movement of chloride and bicarbonate ions across the apical cell surface. Defective CFTR results in an absence of bicarbonate transport, which functions in part to chelate Ca2+, a divalent cation found in abundance in mucin granules in normal conditions; this yields a hyperviscous and adhesive mucus on the respiratory and gastrointestinal tracts of patients with CF. Bronchial mucins are glycosylated proteins with neutral and negative sugars modified by negatively charged sialic and neuraminic …

Transcriptional Changes Underpinning Poor Prognosis And Chemoresistance In Pancreatic Cancer, Ryne Ramaker

All ETDs from UAB

With a 5-year survival rate of 7% and only marginal improvements in recent dec-ades, pancreatic adenocarcinoma (PDAC) survival statistics present a disheartening chal-lenge. A majority of the high mortality rate associated with PDAC is due to late-stage diagnosis and limited efficacy of the current chemotherapeutic arsenal. This work is largely focused on the ~20% of tumors detected prior to metastasis for which curative surgical resection can be combined with chemotherapy and radiation therapy, increasing the 5 year survival rate to ~25%. Although a subset of these patients who undergo surgi-cal resection experience sustained remission, a majority of patients still relapse …

Elucidating The Role Of Hedgehog Signaling In Modulating Macrophage Function In Breast Cancer, Ann Hanna

All ETDs from UAB

In the tumor microenvironment, breast cancer cells participate in crosstalk with the surrounding stroma. This tumoral-stromal interaction forms a balance that dictates tumor suppressing or tumor promoting response mechanisms. Macrophages in the tumor microenvironment are plastic and can mediate several functions depending on their activation states. Tumor associated macrophages co-exist as two major phenotypes: anti-tumorigenic and immune-eliciting classically activated M1 as well as tumor-promoting and immune-suppressive alternatively activated M2 macrophages. Alternatively activated macrophages are specifically associated with more aggressive stages and poor clinical outcomes in breast cancer patients as they suppress the tumoricidal properties of the immune system, thus facilitating …

Applications Of Next-Generation Sequencing And Functional Genomics In Translational Medicine, Andrew Hardigan

All ETDs from UAB

The development of next-generation sequencing (NGS) technologies has led to unparalleled advances in our understanding of the genetic basis of disease, evolution, and genetic and genomic regulation. Building on the advances made in the Human Genome Project and more recent efforts such as the Encylopedia of DNA Elements (ENCODE) and the Roadmap Epigenomics Project, whole-genome and whole-exome sequencing (WGS/WES) and a wide variety of NGS-enabled functional assays are bridging the gap between scientific discovery and clinical medicine. This trend towards genomically informed “bench-to-bedside” translational medicine is driven in large part by the sharply decreasing costs for NGS in both clinical …

Epigenetic Regulation Of Stem Cell Fate Determination And Tumorigenesis, Kushani Shah

All ETDs from UAB

It is unclear how H3K4 methylation, an epigenetic modification associated with gene activation, regulates stem cell fate determination and tumorigenesis. DPY30 is one of the core subunits of the SET1/MLL complex in mammals responsible for H3K4me. DPY30 enhances the H3K4me activity of the SET1/MLL complex. Here, I sought to define role of DPY30 and H3K4me3 in postnatal neurogenesis and hematopoietic malignancies. Using a conditional knockout model, I found that Dpy30 deficiency halts the development of postnatal hippocampus, the subventricular zone, and cerebellum. Deficiency in cerebellum is most likely the cause of uncoordinated ataxia-like movements in these mice. By deleting Dpy30 …

Regulation Of Effector Cd4 T Cell Pathogenicity During Chronic Inflammation, Boyoung Shin

All ETDs from UAB

Effector CD4 T cells are essential for the balance between pro- and anti-inflammatory immune responses during homeostasis. Dysregulation of effector CD4 T cell responses results in chronic inflammatory disorders such as Inflammatory Bowel Disease (IBD) and Multiple Sclerosis (MS), however therapeutic options for these diseases are limited. Understanding the mechanisms that regulate pathogenicity of effector CD4 T cells is critical to devise new therapeutic interventions. Herein we show two different mechanisms that profoundly impact pathogenic potential of CD4 T cells by regulating heterogeneities of effector functions and differentiation states. Different subsets of effector CD4 T cells utilize distinct metabolic pathways. …

Amygdala-Frontal Connectivity Predicts Internalizing Symptom Recovery Among Inpatient Adolescents, Amanda Venta, Carla Sharp, Michelle Patriquin, Ramiro Salas, Elizabeth Newlin, Kaylah Curtis, Philip Baldwin, Christopher Fowler, B Christopher Frueh

Staff and Researcher Publications

Background: The possibility of using biological measures to predict the trajectory of symptoms among adolescent psychiatric inpatients has important implications. This study aimed to examine emotion regulation ability (measured via self-report) and a hypothesized proxy in resting-state functional connectivity [RSFC] between the amygdala and frontal brain regions as baseline predictors of internalizing symptom recovery during inpatient care.

Methods: 196 adolescents (61% female; Mage = 15.20; SD = 1.48) completed the Achenbach Brief Problem Monitor (BPM) each week during their inpatient care. RSFC (n = 45) and self-report data of emotion regulation (n = 196) were collected at baseline.

Results: The …

Clinical Utility Of The Dsm-5 Alternative Model For Borderline Personality Disorder: Differential Diagnostic Accuracy Of The Bfi, Scid-Ii-Pq, And Pid-5, J Christopher Fowler, Alok Madan, Jon G Allen, Michelle Patriquin, Carla Sharp, John M Oldham, B Christopher Frueh

Staff and Researcher Publications

Background: With the publication of DSM 5 alternative model for personality disorders it is critical to assess the components of the model against evidence-based models such as the five factor model and the DSM-IV-TR categorical model. This study explored the relative clinical utility of these models in screening for borderline personality disorder (BPD).

Methods: Receiver operator characteristics and diagnostic efficiency statistics were calculated for three personality measures to ascertain the relative diagnostic efficiency of each measure. A total of 1653 adult inpatients at a specialist psychiatric hospital completed SCID-II interviews. Sample 1 (n=653) completed the SCID-II interviews, SCID-II Questionnaire (SCID-II-PQ) …