Medical Sciences Commons^™

Examining The Roles Of Gabaa Receptor Subtypes In Anxiety And Anxiolysis: Focusing On The Basolateral Amygdala, Yudong Gao

Theses and Dissertations (ETD)

The investigation of the differential roles GABA_A receptor (GABA_AR) subtypes play in mediating various behaviors such as fear and anxiety was an intriguing research topic over the past decade. At present, most evidence suggests that benzodiazepine (BZ)-induced anxiolysis is primarily mediated by GABA_ARs containing the α2-subunit (α2-subtype). However, there is conflicting evidence as to whether α1- and α3-subtypes might also be involved in BZ-induced anxiolysis. In an attempt to further discern the role played by different α-subtype GABA_ARs in BZ-induced anxiolysis both systemically and within the basolateral amygdala (BLA), a brain region crucial …

The Role Of Drak2 In T Cell Function And Autoimmunity, Tarsha L. Harris

Theses and Dissertations (ETD)

The immune system utilizes many regulatory mechanisms to limit immune responses and ensure that immune cells target foreign pathogens and not healthy cells of the body. However, some immune cells can escape these checkpoints and attack the body’s healthy cells, leading to tissue destruction and devastating autoimmune disorders. For example, multiple sclerosis (MS) occurs when immune cells attack the myelin sheath surrounding neurons of the central nervous system (CNS). Likewise, the destruction of pancreatic islet cells by dysregulated immune cells leads to type 1 diabetes (T1D). Remarkably, there are more than 80 types of autoimmune diseases. An estimated 50 million …

Hit Identification For Pkcζ Inhibitors: Structure-Based Optimization, Virtual Screening, And Biological Evaluation, Xiaoxin Wu

Theses and Dissertations (ETD)

Protein kinase C ζ (PKCζ) is believed to be a promising target for the treatment of some diseases, including inflammatory diseases, obesity and diabetes. Hit identification of PKCζ inhibitors was conducted by structure-based modification, virtual screening and biological evaluation. Among all the compounds selected and synthesized, compound JW-1-60A showed moderate activity against PKCζ at 30 μM and 100 μM. The molecular modeling studies showed that the binding mode of JW-1-61A was very close to the binding mode of JP-3-149, a reported PKCζ inhibitor with very potent activity, which might partially explain the moderate activity of JW-1-61A. Based on the structure …

Interaction Between Two E3 Ligases, Nedd8ylated Cullin And Hhari, Kheewoong Baek

Theses and Dissertations (ETD)

RBR (RING1-in between RING-RING2) is a special type of E3 ubiquitin ligase containing three zinc-binding RING (Really Interesting New Gene) domains, while adopting mechanisms of HECT (Homologous to E6-AP Carboxyl Terminus) for substrate ubiquitination. Most well known RBRs include Parkin and HOIP, which are associated with Parkinson’s disease and innate immune deficiency. However, it is not well known how the RBR proteins gain activity, as they are known to be autoinhibited. Here I show that a specific F430A, E431A, E503A triple mutation of RBR protein HHARI (Human homologue of Ariadne) and its interaction with NEDD8ylated cullin RING ligase can both …

Antibodies To Heterogenous Nuclear Ribonucleoprotein A1 Penetrate Neurons Leading To Multiple Downstream Effects Resulting In Neurodegeneration, Joshua Nathan Douglas

Theses and Dissertations (ETD)

Multiple sclerosis (MS) is the most common demyelinating disorder of the central nervous system. MS is believed to occur in genetically susceptible individuals due to an unknown environmental stimulus. MS patients produce autoantibodies to heterogenous nuclear ribonuclearprotein A1 (hnRNP A1), an RNA binding protein (RBP) highly expressed in neurons. hnRNP A1 functions in pre-mRNA splicing, mRNA trafficking, and translation. Furthermore, the anti-hnRNP A1 antibodies are specific to a N-terminal region termed ‘M9’ which serves as a nuclear export sequence/nuclear localization sequence (NES/NLS) responsible for nuclear/cytoplasmic transport of the protein. In this manuscript we will provide data revealing that anti-hnRNP A1 …

Pten Signaling In Regulatory T Cells And Inflammatory Disease, Sharad Krishna Shrestha

Theses and Dissertations (ETD)

Regulatory T (Treg) cells suppress CD4+ T cell responses during homeostasis and inflammation to prevent autoimmunity and other immune disorders. Although the transcriptional and epigenetic programs impacting Treg cell function have been extensively studied, the signaling and metabolic pathways underlying Treg stability and function are not fully understood. In this study, we determined the role of the phosphatase PTEN in Treg cells. We found that specific depletion of PTEN in Treg cells results in excessive TH1 and T follicular helper cells (TFH) responses, associated with elevated germinal center (GC) B cells and spontaneous development of autoimmune and lymphoproliferative disease in …

Dissecting The Novel Roles Of Trim56 In Antiviral Innate Immunity, Baoming Liu

Theses and Dissertations (ETD)

The tripartite motif-containing (TRIM) proteins have emerged as a new class of host antiviral restriction factors, with several demonstrating roles in regulating innate antiviral responses. Of >70 known TRIMs, TRIM56 inhibits replication of bovine viral diarrhea virus, a ruminant pestivirus of the family Flaviviridae, but has no appreciable effect on VSV, a rhabdovirus. We have also shown that TRIM56 forms a complex with the Toll-like receptor-3 (TLR3) adaptor, TRIF, via its C-terminal residues 621-750, and augments TLR3-mediated interferon (IFN) induction and establishment of an antiviral state. Yet, TRIM56’s antiviral spectrum and the precise underlying mechanisms by which TRIM56 executes …

Development And Evaluation Of Amphotericin B Loaded Iron Oxide Nanoparticles For Targeted Drug Delivery To Systemic Fungal Infections, Pavan Balabathula

Theses and Dissertations (ETD)

A targeted nanotheronostic drug delivery system to diagnose and treat life threatening invasive fungal infections (IFIs) such as cryptococcal meningitis was designed, developed, characterized, and evaluated. To address the development processes, first, iron oxide nanoparticles (IONP) (34-40 nm) coated with bovine serum albumin (BSA), loaded and targeted with amphotericin B (AMB) (AMB-IONP) was formulated by applying a layer by layer approach. Several designs (A, B, C, D, & E) of AMB-IONP were developed and their physicochemical properties such as drug loading with HPLC method, particle size, poly dispersity index (PDI), and ζ-potential using dynamic light scattering (DLS) technique, morphology with …

Genetic Control Of Survival And Weight Loss During Pneumonic Burkholderia Pseudomallei (Bp) Infection, Felicia D. Emery

Theses and Dissertations (ETD)

Burkholderia pseudomallei (Bp) is a saprophytic, gram-negative aerobe and the causative agent of the disease melioidosis. Melioidosis is an infectious disease that occurs in humans and animals and is prevalent in Southeast Asia, northern Australia and other tropical areas. Transmission occurs through direct contact with the organism via ingestion, inhalation, or through open wounds and skin abrasions. Clinical presentation is extremely variable and can range from acute septicemia with bacterial dissemination to distant sites, to an isolated pulmonary infection. Treatment of melioidosis can be problematic because it is often difficult to diagnose and Bp is resistant to a diverse group …

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 …

Development Of Oral Vaccines Against Lyme Disease, Rita Raquel Dos Anjos De Carvalho E Melo

Theses and Dissertations (ETD)

Lyme Disease, caused by the spirochete Borrelia burgdorferi, is the most common vector-borne disease in the United States and Europe. If left untreated, it can lead to permanent damage to the nervous and musculoskeletal systems. In some cases, patients that receive the recommended antibiotic therapy develop a debilitating health condition associated with substantial health care costs. Despite current preventive measures, the incidence and the geographic distribution of Lyme Disease continues to increase. Recent estimates from CDC suggest that the true number of cases of Lyme Disease in the US is approximately 300,000 per year. Yet, there is currently no vaccine …

Functional Analysis Of Genomic Variation And Impact On Molecular And Higher Order Phenotypes, Ashutosh Kumar Pandey

Theses and Dissertations (ETD)

Reverse genetics methods, particularly the production of gene knockouts and knockins, have revolutionized the understanding of gene function. High throughput sequencing now makes it practical to exploit reverse genetics to simultaneously study functions of thousands of normal sequence variants and spontaneous mutations that segregate in intercross and backcross progeny generated by mating completely sequenced parental lines. To evaluate this new reverse genetic method we resequenced the genome of one of the oldest inbred strains of mice—DBA/2J—the father of the large family of BXD recombinant inbred strains. We analyzed ~100X wholegenome sequence data for the DBA/2J strain, relative to C57BL/6J, the …

Adverse Effects Of Asparaginase In Pediatric Patients With Acute Lymphoblastic Leukemia, Chengcheng Liu

Theses and Dissertations (ETD)

Acute lymphoblastic leukemia (ALL) is the most common type of childhood cancer. Asparaginase is a critical treatment component for ALL. However, its use is complicated by adverse effects, such as hypersensitivity, osteonecrosis and pancreatitis.

Hypersensitivity to asparaginase typically requires discontinuation of current formulation and substitution with other formulations, but the differential diagnosis can be challenging, and the diagnostic utility of antibody tests is unclear. We comprehensively analyzed anti-Elspar (native E.coli asparaginase) IgG antibodies in 410 pediatric patients treated on an asparaginaseintensive front-line clinical trial. Of 169 patients (41.2%) who exhibited clinical allergy, 147 (87.0%) were positive for anti-Elspar antibody. Of …

Effects Of Cocaine Sensitization On Drug Self-Administration, Mesocorticolimbic Sapap Levels, And Prefrontal Ionotropic Glutamate Receptors, Kyle Christopher Summers

Theses and Dissertations (ETD)

Towards the goal of improving the knowledge base of how drugs of abuse function to create addicts and using currently uninvestigated areas of this knowledge base, we focused our research studies the male albino rat, and strived to explain how cocaine sensitization alters particular molecular mechanisms in the mesocorticolimbic system related to glutamate receptors, SAPAPs, and affects drug self-administration. Taking all the previously discussed research studies into consideration, we hypothesized that low-dose cocaine self-administration would yield a significant elevation in drug seeking behavior for psychostimulant sensitized animals. For specific changes at the PSD, we hypothesized that acute cocaine exposure and/or …

Integration Of Atm, Atr, And Dna-Pkcs Signaling Maintains Genome Integrity During Neurogenesis, Vanessa D. Enriquez-Rios

Theses and Dissertations (ETD)

The DNA damage response (DDR) orchestrates a network of cellular processes such as cell cycle progression, DNA repair, and apoptosis when complex DNA lesions arise to maintain genomic integrity. ATM, ATR, and DNA-PKcs (encoded by PRKDC) are related phosphatidylinositol-3-kinase like serine/threonine kinases (PIKK) that collectively regulate the DDR network. Studies have demonstrated these kinases can phosphorylate many of the same substrates, suggesting a significant potential for functional redundancy. However, deficiencies in these kinases have been linked to distinct neural degenerative and developmental disorders, underscoring their unique functions for maintain genomic integrity during nervous system development.

Here we utilized mouse genetic …

Structural-Based Investigation Of Fak And P130cas In Focal Adhesion, Chi Zhang

Theses and Dissertations (ETD)

Cell migration is an integrated multistep process accompanying us throughout life, from birth to death. It contributes to a variety of biological activities and has been implicated in many pathological conditions, including cancer, primary immunodeficiency diseases, vascular diseases, and mental retardation. Cell migration has been considered to be a three-step cyclic process including polarization, protrusion and retraction. The initiation and extension of the protrusion is driven by actin polymerization, and is stabilized by attaching to the extracellular matrix (ECM) or adjacent cells. The cell-ECM attachment sites are named focal adhesions (FAs), which are dynamic, large protein complexes containing more than …

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 …

Synthesis And Characterization Of Methacrylated Hyaluronan-Based Hydrogels For Tissue Engineering, Keegan Bradley Compton

Theses and Dissertations (ETD)

Polymers have revolutionized the field of tissue engineering due to the countless possibilities of scaffolds that can be constructed from such a material. Through conjugation of other functional groups onto a polymer backbone, the mechanical properties of polymers can be controlled and has the ability to span a wide range of strengths, allowing for application in multiple tissue environments. One such polymer, hyaluronic acid (HA), is a natural polysaccharide found most abundantly in the extracellular matrix (ECM) of connective tissues with structural, lubricating, and wound healing functions in the human body; for this reason, HA has great potential for utilization …

Mapping The Spatial And Temporal Dynamics Of Sensorimotor Integration During The Perception And Performance Of Wallowing, Megan E. Cuellar

Theses and Dissertations (ETD)

Similar to other complex sequences of muscle activity, swallowing relies heavily upon ‘sensorimotor integration.’ It is well known that the premotor cortex and primary sensorimotor cortices provide critical sensorimotor contributions that help control the strength and timing of swallowing muscle effectors. However, the temporal dynamics of sensorimotor integration remains unclear, even when performed normally without neurological compromise. Recent advances in EEG analysis blind source separation techniques via independent component analysis offer a novel and exciting opportunity to measure cortical sensorimotor activity in realtime during swallowing, concurrently with muscle activity during swallow initiation. In the current study, mu components were identified, …

Mrp4-Dependent Regulation Of Fibroblast Migration, Chandrima Sinha

Theses and Dissertations (ETD)

Roles of cyclic nucleotides and cyclic nucleotide-dependent signaling molecules in regulating several signaling pathways including cell migration have long been known. However, the new and revolutionary concept is that it is not just the absence or presence of cyclic nucleotides, but a highly coordinated balance between these molecules regulates cell migration. Multi-drug resistance protein 4 (MRP4), is a member of the large family of ATP binding cassette (ABC) transporter proteins, that localizes to the plasma membrane and functions as a nucleotide efflux transporter and thus plays a pivotal role in the regulation of intracellular cyclic nucleotide dynamics. In our study …

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 …

Strengths And Weaknesses Of Hybrid Tpr Technology For Obtaining Structural And Mechanistic Insights Into Tpr Proteins, Shanshan Yu

Theses and Dissertations (ETD)

Tetratricopeptide (TPR) repeats are a 34-residue helix-turn-helix motif that when repeated pack into a superhelical structure. TPR domains are frequently found mediating protein-protein interactions, often through a central groove. One protein complex bearing numerous TPR repeats is the Anaphase Promoting Complex (APC). The anaphase-promoting complex (APC) is a multi-subunit complex, which orchestrates mitotic cell cycles. APC is an E3 ligase in the ubiquitin cascade, and directs the 26S proteosome degradation of cell-cycle regulators. Throughout mitotic progression, proteins that are key regulators of the cell cycle are assembled with polyubiquitin chains by APC.

One domain of the human APC is comprised …

Effect Of Nedd4 Haploinsufficiency On Insulin Sensitivity, Adiposity And Neuronal Behaviors, Jingjing Li

Theses and Dissertations (ETD)

The neural precursor cell expressed developmentally down-regulated gene 4 (NEDD4) is a HECT-type E3 ubiquitin ligase that has received broad attention in recent years. Many of its reported substrates are active players in metabolism, implying a potential role of NEDD4 itself in metabolic regulation. Since homozygous Nedd4 deletion leads to embryonic or perinatal lethality, we investigated the function of NEDD4 in metabolic regulation in vivo, using Nedd4- haploinsufficient mice in a high fat diet-induced obesity (HFDIO) model.

Our studies show that Nedd4-haploinsufficient mice fed a normal diet (ND) exhibited decreased body weight in both genders and proportionally reduced tissue mass …

Novel Insights Into The Role Of The Smoothened Cysteine Rich Domain In Hedgehog Signalling, Rajashree Rana

Theses and Dissertations (ETD)

The Hedgehog (Hh) signal transduction pathway functions as one of the key developmental pathways and deranged Hh signalling is associated with numerous cancer and tumor conditions. The Smoothened (Smo) G protein coupled receptor (GPCR) functions as the signal transducer of the Hh pathway and is the most attractive drug target of the pathway. The structure of the Smo receptor includes seven membrane spanning domains, extracellular and intracellular loops connecting the membranous domains and the extracellular cysteine rich domain (CRD). The extracellular CRD of the Smo receptor is homologous to the Frizzled (FzD) CRD. The FzD CRD interacts with the physiological …

Autoimmune Susceptibility Imposed By Public Tcrβ Chains, Yunqian Zhao

Theses and Dissertations (ETD)

The major histocompatibility complex (MHC) is the strongest genetic risk factor for autoimmunity. It acts together with a corresponding TCR repertoire, yet, considering the extent of the repertoire's diversity, how this imposes disease susceptibility on a population is not well understood. We address the hypothesis that shared or public TCR, those present in most individuals, modulate autoimmune risk. High resolution analyses of autoimmune encephalomyelitis-associated T-cell receptor β chain (TCRβ) showed preferential utilization of public TCR sequences, implicating them in pathogenesis. Disease-associated public TCRβ, when transgenically expressed in association with endogenously rearranged T-cell receptor α chain (TCRα), could further endow unprimed …

Genetic And Chemical Dissection Of Bloodbrain Barrier Development In Zebrafish, Robyn Anne Umans

Theses and Dissertations (ETD)

The blood-brain barrier (BBB) maintains a homeostatic environment as well as prohibits the entrance of xenobiotics into the brain. Because of these qualities, drug delivery is a fundamental challenge for the treatment of many diseases of the central nervous system (CNS). Along with limiting the access of therapeutics into the brain, the BBB is also impaired in CNS pathologies. Understanding the molecular cues that are essential for healthy BBB development and integrity may reveal targets for drug delivery leading to decreased progression or possible treatment of many detrimental CNS diseases. While the central features of the BBB have been accepted, …

The Role Of Mcl-1 In The Heart: Gateway From Life To Death, Xi Wang

Theses and Dissertations (ETD)

MCL-1 is an essential BCL-2 family member that promotes the survival of multiple cellular lineages, but its role in cardiac muscle has remained unclear. Here, we have demonstrated that cardiac-specific ablation of Mcl-1 results in a rapidly fatal, dilated cardiomyopathy preceded by loss of myofibrils and cardiac contractility, abnormal mitochondria ultrastructure, defective mitochondrial respiration, and impaired autophagy. Genetic ablation of both pro-apoptotic effectors (Bax and Bak) could largely rescue the lethality and impaired cardiac function induced by Mcl-1 deletion. However, Mcl-1-, Bax-, and Bak-deficient hearts still revealed mitochondrial ultrastructural abnormalities and displayed deficient mitochondrial respiration, and are hypersensitive to chronic …

Functional And Genetic Analysis Of Choroid Plexus Development In Zebrafish, Hannah Elizabeth Henson

Theses and Dissertations (ETD)

The choroid plexus (CP) is an epithelial based structure localized within the brain ventricles and functions as the blood-cerebrospinal fluid barrier (BCSFB). Under normal conditions, the CP is responsible for generating the cerebrospinal fluid (CSF) and regulating its components. Abnormal CP function has been associated with neurodegenerative diseases, tumor formation in CP epithelia (CPe), and hydrocephalus. Despite the significant role of the CP in these disorders, little research has been done to characterize its functional properties and genetically dissect the pathways involved in normal CP development and disease. For this study, we have utilized zebrafish, (Danio rerio), as a model …

Adenosine Production Is Essential For Closing The Critical Period Of Cortical Plasticity, Rachel A. Chassan

Theses and Dissertations (ETD)

Sensory inputs from the external world are represented as highly organized systems in the adult brain for effective adaptation to the environment. At the cortical level, this organization is referred to as cortical maps. The establishment of cortical maps begins with early life experiences during the critical period, a brief period during development of heightened sensitivity to sensory stimuli. During this time, organization of cortical maps is plastic and highly subject to change through passive sensory experience. As an animal matures, the critical period closes and changes to cortical maps occur less freely. The cellular mechanisms of cortical map plasticity …

The Mi-2 Homolog Mit1 Actively Positions Nucleosomes Within Heterochromatin To Suppress Transcription, Kevin M. Creamer

Theses and Dissertations (ETD)

Eukaryotic DNA is packaged into the nucleus in complex with proteins that regulate access and utilization of the genetic material. These DNA and protein complexes form a dynamic structure known as chromatin. Nucleosomes are the repeating unit of chromatin, and consist of DNA wrapped around an octamer of histone proteins. Nucleosomes can then be modified and spatially arranged to facilitate processes such as transcription, DNA replication, and repair. A special transcriptionally repressive chromatin structure assembles onto gene-poor, repetitive regions of the genome known as constitutive heterochromatin. Mit1 is the putative chromatin remodeling subunit of the fission yeast Snf2/HDAC repressor complex …