Biochemistry, Biophysics, and Structural Biology Commons^™

Defining The Role Of Tyrosine Phosphorylation In The Regulation Of Connexin43 In Cardiac Diseases, Li Zheng

Theses & Dissertations

Connexins are integral membrane proteins that oligomerize to form gap junction channels. Ions and small molecules diffuse intercellularly through these channels, allowing individual cellular events to synchronize into the functional response of an entire organ. Gap junction channels composed of Connexin43 (Cx43) mediate electrical coupling and impulse propagation in the normal working myocardium. In the failing heart, Cx43 remodeling (decreased expression, altered phosphorylation state, loss at intercalated discs, and increased presence at lateral membranes) contributes to rhythm disturbances and contractile dysfunction. While there is considerable information regarding key interactions of Cx43 in the regulation of gap junction channels, unfortunately, the …

Delivery Of Small Molecule And Rna Using Synthetic Polymeric Micelles And Multifunctional Exosomes For The Treatment Of Type 1 Diabetes, Yang Peng

Theses & Dissertations

Type 1 diabetes is one of the most challenging chronic autoimmune diseases. The destruction and dysfunction of insulin-secreting β cells are the results of inflammatory infiltration and the synergistic effect of multiple immune cells. The aim of this dissertation is to develop novel and reliable therapeutic approaches to advance the treatment of T1D: including chemical modification of a broad-spectrum immunosuppressant, co-application of small molecule based immune intervention and siRNA based β cell preservative therapy, and administration of a PI3K-δ/γ dual inhibitor to specifically target immune cells, utilizing synthetic polymeric micelles or natural produced multi-functional exosomes derived from human bone marrow …

Alzheimer's And Amyloid Beta: Amyloidogenicity And Tauopathy Via Dyshomeostatic Interactions Of Amyloid Beta, Jordan Tillinghast

Senior Honors Theses

This paper reviews functions of Amyloid-β (Aβ) in healthy individuals compared to the consequences of aberrant Aβ in Alzheimer’s disease (AD). As extraneuronal Aβ accumulation and plaque formation are characteristics of AD, it is reasonable to infer a pivotal role for Aβ in AD pathogenesis. Establishing progress of the disease as well as the mechanism of neurodegeneration from AD have proven difficult (Selkoe, 1994). This thesis provides evidence suggesting the pathogenesis of AD is due to dysfunctional neuronal processes involving Aβ’s synaptic malfunction, abnormal interaction with tau, and disruption of neuronal homeostasis. Significant evidence demonstrates that AD symptoms are partially …

Autophagy Protein Nrbf2 Has Reduced Expression In Alzheimer's Brains And Modulates Memory And Amyloid-Beta Homeostasis In Mice, Veronik Lachance, Qian Wang, Eric Sweet, Insup Choi, Cui-Zan Cai, Xu-Xu Zhuang, Jessica Li Jiang, Robert D. Blitzer, Ozlem Bozdagi-Gunal, Bin Zhang, Jia-Hong Lu, Zhenyu Yue

Biology Faculty Publications

Background Dysfunctional autophagy is implicated in Alzheimer's Disease (AD) pathogenesis. The alterations in the expression of many autophagy related genes (ATGs) have been reported in AD brains; however, the disparity of the changes confounds the role of autophagy in AD. Methods To further understand the autophagy alteration in AD brains, we analyzed transcriptomic (RNAseq) datasets of several brain regions (BA10, BA22, BA36 and BA44 in 223 patients compared to 59 healthy controls) and measured the expression of 130 ATGs. We used autophagy-deficient mouse models to assess the impact of the identified ATGs depletion on memory, autophagic activity and amyloid-beta (A …

The Role Of Inositol Polyphosphate-4-Phosphatase Type Ii B (Inpp4b) In Obese Models And Endocrine Cancers, Manqi Zhang

FIU Electronic Theses and Dissertations

INPP4B is a dual-specificity phosphatase and a tumor suppressor in prostate and breast cancers. Progression of the prostate and breast cancers depends on the androgen receptor (AR) or estrogen receptor alpha (ERα) signaling, respectively. In this work we demonstrated that INPP4B reprograms ERα transcriptional activity in breast cancer. INPP4B maintains expression and protein levels of progesterone receptor (PR), an ERα direct target gene required for mammary gland development. Consistently we demonstrated that Inpp4b knockout severely impairs lateral branching in the mammary gland of maturing virgin females. In advanced prostate cancer, activation and transcriptional reprogramming of AR frequently coincides with the …

Discovery Of Novel Mechanisms Regulating Cancer Extravasation In The Chorioallantoic Membrane Model, Yohan Kim

Electronic Thesis and Dissertation Repository

Cancer metastasis is a multistep process that begins with the invasion of tumour cells into the stroma and migration towards the blood vessels. Tumour cells that have entered the bloodstream must then survive and leave by a process known as extravasation. Finally, extravasated cells proliferate and establish the secondary site in the metastatic cascade. Although extravasation encompasses key events during cancer cell invasion to aid in the development of effective treatments, an in vivo model that rapidly, reproducibly and economically recapitulates cancer cell extravasation is needed. Therefore, the objectives of my research were to 1) establish and validate an in …

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched …

Incidence And Prevalence Of Francisella Noatunensis Subsp. Orientalis (Fno) Pathogenic Infections In Feral Hawaiian Tilapia, Daquille Peppers

Biology Theses

Aquaculture has become a major food source for many countries and continues to grow each year. However, many of the fishes that are farmed are susceptible to pathogenic infections such as Francisellosis, a bacterial infection that contributes to disease and high mortality rate in many populations of farmed and wild fish around the world. In 1994, feral and farmed populations of tilapia (e.g. Oreochromis mossambicus) on Oahu, Hawaii were found to be infected with a novel Francisellosis strain, Francisella noatunensis subsp. orientalis (Fno). To prevent the spread of this pathogen, the Hawaii Department of Aquaculture (HDOA) initiated …

Natural Autoantibodies: Origin, Function And Utility For Diagnosis Of Disease, Abhirup Sarkar

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies (aAbs) by the simplest definitions have been described as antibodies against self-antigens and were exclusively associated with autoimmune diseases. Eventually, studies demonstrated that they are abundant in the blood of all human sera, regardless of age, gender, or the presence or absence of disease, and were thus named as ‘natural autoantibodies’. The underlying reason for their ubiquity has remained elusive, but we have hypothesized that they are responsible for clearing blood-borne cell and tissue debris generated under conditions of health and disease. To test this, we chose to use two widely different disease model systems, namely neurodegenerative diseases and …

Investigation Of Microbiota In Health And Disease Of Poultry, Bishnu Adhikari

Graduate Theses and Dissertations

The microbiotas play vital roles in health and diseases of both humans and animals. 16S rRNA genes sequence analysis is one of the most popular and commonly used methods in the analysis of microbiotas associated with hosts. In this dissertation, the microbiotas of chickens (broilers, breeders, and layers) and turkeys were evaluated by 16S rRNA gene sequencing. Characterization of the culturable subpopulations of Lactobacillus in the chicken gut can serve as a valuable resource for probiotic development. In Chapter 2, Lactobacillus subpopulations recovered on MRS from chicken gut were defined comprehensively for the first time using 16S rRNA gene profiling, …

Microvascular Stenosis In Critical Limb Ischemia: Role Of Partial Endothelial To Mesenchymal Transition, Jacqueline M. Chevalier

Electronic Thesis and Dissertation Repository

Critical limb ischemia (CLI) is a widespread and debilitating manifestation of atherosclerosis. Unfortunately, revascularization strategies are often precluded or unsuccessful, resulting in amputation. A major reason for treatment failure is likely co-existing abnormalities in ­­the microvasculature. However, the specific microvascular defects present in end-stage PAD in humans remain unknown.

The purpose of this study was to delineate abnormalities in the microvascular wall in the critically ischemic skeletal muscle of patients with CLI.

To elucidate the microvascular landscape in CLI, we studied human tibialis anterior and gastrocnemius muscles harvested from below-knee amputations of 10 individuals with CLI. Control muscles are from …

A High Throughput Assay For The Detection Of Stimulator Of Interferon Genes (Sting) Agonists, Michael J. Ingling

Graduate School of Biomedical Sciences Theses and Dissertations

The innate immune system includes a menagerie of different cell types, each with a different role in the process of monitoring the body for invaders and presenting gathered debris (antigen) to the adaptive immune system. Somatic cells have intracellular receptors for the same purpose. Cancer cells, however, have avoided these methods of detection despite, in many cases, the tumor’s immunogenic traits. Immuno-oncology is a field dedicated to the immunological traits of tumors, more recently finding ways of instigating an immune response against tumors. In this regard, STING, a receptor of cyclic dinucleotides (CDN), has come to the forefront of immuno-oncology. …

The Wet Bridge Transfer System: An Novel In Vitro Tool For Assessing Exogenous Surfactant As A Pulmonary Drug Delivery Vehicle, Brandon J. Baer

Western Research Forum

Background:

Due to its complex branching structure, direct drug delivery to the remote areas of the lung is a major challenge. Consequently, most therapies, such as those treating pulmonary infection and inflammation, must utilize large systemic dosing, with the potential for adverse side effects. A novel alternative strategy is to use exogenous surfactant, a material capable of distributing throughout the lung, as a pulmonary drug delivery vehicle.

Objective:

Utilize an in vitro transferring system to assess exogenous surfactant (BLES) as a pulmonary delivery vehicle for different therapeutics.

Methods:

An in vitro technique was developed to simultaneously study surfactant delivery and …

Topoisomerase And Tyrosyl-Dna-Phosphodiesterase Ratio As An Indicator For The Response Of Glioblastoma Cancer To Topoisomerase Targeting Anticancer Drugs, Wenjie Wang

FIU Electronic Theses and Dissertations

Glioblastoma (GBM) patients have an estimated survival of ~15 months, with the standard of care (surgery, radiation, and chemotherapy) that has only modestly enhanced patient survival. Identifying biomarkers representing vulnerabilities in GBM biology may allow for the selection of effective and safe chemotherapy options. Irinotecan (IRT), a genotoxic compound currently in clinical trials for GBM, targets topoisomerase I (TOP1) by forming an irreversible ternary DNA-TOP1 cleavage complex (TOP1cc) and leads to apoptosis. Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a crucial repair enzyme that rescues TOP1cc and reduces the effectiveness of IRT. In the current study, we evaluate the value of the …

A Rapid Viability And Drug‑Susceptibility Assay Utilizing Mycobacteriophage As An Indicator Of Drug Susceptibilities Of Anti‑Tb Drugs Against Mycobacterium Smegmatis Mc2 155, Gillian Catherine Crowley, Jim O'Mahony, Aidan Coffey, Riona G. Sayers, Paul D. Cotter

Department of Biological Sciences Publications

Background: A rapid in-house TM4 mycobacteriophage-based assay, to identify multidrug resistance against various anti-tuberculosis drugs, using the fast-growing Mycobacterium smegmatis mc² 155 in a microtiter plate format was evaluated, based on phage viability assays. Methods: A variety of parameters were optimized before the study including the minimum incubation time for the drugs, phage and M. smegmatis mc² 155 to be in contact. An increase in phage numbers over 2 h was indicative that M. smegmatis mc² 155 is resistant to the drugs under investigation, however when phage numbers remained static, M. smegmatis mc² 155 found to …

Arachidin 3 Modulation Of Lipid Metabolism In Rotavirus Infections, Stormey Wisdom

Electronic Theses and Dissertations

Rotavirus (RV) can cause severe and deadly gastroenteritis in young children, infants, and immunocompromised individuals. Previous studies have shown that arachidin 3 (A3) inhibits RV replication, and that RV replication is dependent on the presence of lipids. This study investigated the alteration of lipid metabolism by A3 in RV infected HT29.f8 cells. A decrease in the RV regulation of lipid biosynthesis genes was observed with the addition of A3 using qRT-PCR. Also, immunofluorescent and histochemical staining for neutral fats, a major component of cellular lipid droplets, revealed an increased accumulation with both RV and RV+A3 when compared to no virus …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

The Role Of Ros In The Progression And Treatment Of Castration-Resistant Prostate Cancer, Dannah R. Miller

Theses & Dissertations

Prostate cancer is the second leading cause of cancer-related deaths in U.S. men, primarily due to the development of castration-resistant (CR) prostate cancer (PCa), of which there are no effective treatment options. Reactive oxygen species (ROS) plays a critical role in prostate carcinogenesis, including the progression of the CR PCa phenotype. ROS regulates both cell proliferation and apoptosis; a moderate increase in ROS can promote proliferation; however, a substantial rise in ROS levels will result in apoptosis. Oxidase p66Shc is elevated in clinical PCa cells and has been associated with a metastatic phenotype of CR PCa cells, promoting PCa cell …

Characterizing Aft1/2-Grx3/4 Interaction And The Role Of Bol2 During Iron Regulation In Saccharomyces Cerevisiae, William Rivers

Senior Theses

Iron dysregulation has been linked to a variety of human diseases, such as anemia, Friedreich’s ataxia, X-linked sideroblastic anemia, sideroblastic-like microcytic anemia, and myopathy. Thus, it is vitally important to understand the mechanisms for regulating intracellular iron. Here, we use fluorescence microscopy techniques in live cells to study interactions of the yeast proteins Grx3/4, Aft1/2, and Bol2, which have been shown to be involved in turning off iron import when the cell has adequate iron. Modified versions of genes encoding these proteins have been incorporated into several yeast backgrounds to use fluorescence to monitor interactions under varying iron levels.

Hybridized Polymeric Nano-Assemblies: Key Insights Into Addressing Mdr Infections, Ryan Landis

Doctoral Dissertations

Multidrug-resistant (MDR) bacteria contribute to more than 700,000 annual deaths world-wide. Millions more suffer from limb amputations or face high healthcare treatment costs where prolonged and costly therapeutic regimens are used to counter MDR infections. While there is an international push to develop novel and more powerful antimicrobials to address the impending threat, one particularly interesting approach that has re-emerged are essential oils, phytochemical extracts derived from plant sources. While their antimicrobial activity demonstrates a promising avenue, their stability in aqueous media, limits their practical use in or on mammals. Inspired by the versatility of polymer nanotechnology and the sustainability …

Ck2 Negatively Regulates 5-Ht4 Receptor Signaling In The Prefrontal Cortex And Mediates Depression-Like Behaviors, Julia Castello Saval

Dissertations, Theses, and Capstone Projects

The serotonergic system has been the major candidate in the pathophysiology of mood related disorders such as anxiety and major depressive disorder (MDD). Unfortunately, current antidepressant drugs are ineffective in 50% of the population and require chronic administration for a period of 3-6 weeks before the onset of therapeutic response. 5-HT4 receptor (5-HT₄R) agonists have emerged as potential candidates for fast antidepressant action, since an antidepressant response can be achieved after 3 days of pharmacological administration in rodents.

This dissertation aims to investigate the role of casein kinase 2 (CK2) as a regulator of 5-HT₄R expression …

A Bird's-Eye View Of The Multiple Biochemical Mechanisms That Propel Pathology Of Alzheimer's Disease: Recent Advances And Mechanistic Perspectives On How To Halt The Disease Progression Targeting Multiple Pathways., Caleb Vegh, Kyle Stokes, Dennis Ma, Darcy Wear, Jerome Cohen, Sidhartha D. Ray, Siyaram Pandey

Touro College of Pharmacy (New York) Publications and Research

Neurons consume the highest amount of oxygen, depend on oxidative metabolism for energy, and survive for the lifetime of an individual. Therefore, neurons are vulnerable to death caused by oxidative-stress, accumulation of damaged and dysfunctional proteins and organelles. There is an exponential increase in the number of patients diagnosed with neurodegenerative diseases such as Alzheimer’s (AD) as the number of elderly increases exponentially. Development of AD pathology is a complex phenomenon characterized by neuronal death, accumulation of extracellular amyloid-β plaques and neurofibrillary tangles, and most importantly loss of memory and cognition. These pathologies are most likely caused by mechanisms including …

Adaptation Of The Streptococcal Collagen-Like Protein 1, Scl1, Of Group A Streptococcus To Recognize Fibronectin Type Iii Repeats, Dudley H. Mcnitt

Graduate Theses, Dissertations, and Problem Reports

Background: Group A Streptococcus (GAS) is responsible more than 700 million infections worldwide each year. Most of these infections start with initial colonization of the throat and skin, which is augmented by surface adhesins. The streptococcal collagen-like protein 1 (Scl1) is a major adhesin expressed by GAS that contains an N-terminal sequence-variable (V) domain, protruded away from the cell surface by the collagen domain. The Scl-V domain is comprised of three pairs of anti-parallel α-helices interconnected by surface-exposed loops. For attachment, GAS adhesins require a portal of entry, such as a wound or breach in the epithelium, to enter …

Giardia Lamblia Growth In Viscoelastic Fluids, Kelly Watanabe

CMC Senior Theses

Giardia lamblia is a single-celled protozoan parasite that when ingested, causes diarrheal disease and infects 33% of people in developing countries. Previous studies observe Giardia in water-like fluids, but Giardia's infectious environment consists of viscoelastic mucus in the small intestine. Therefore, Giardia was cultured in viscoelastic fluids, and its population growth was observed in vitro. To create shear-thinning viscoelastic fluids, 0.2% and 0.4% long-chain polyacrylamide (LCPAM) was added to cell culture media. Giardia was cultured in control media, 0.2% LCPAM, and 0.4% LCPAM, and population growth was quantitatively determined over time. Increasing LCPAM concentration resulted in a solution with …

Regulation Of The Long Non-Coding Rna Fam83h-As1 By Human Papillomavirus In Cervical Cancer, Jamie Ann Barr Ph.D.

Graduate Theses, Dissertations, and Problem Reports

Non-coding RNAs (NcRNAs), such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), have been found to be involved in a variety of critical biological processes, and dysregulation of ncRNAs have been involved with several human diseases including cancer.

High-risk human papillomavirus (HPV) infection is one of the first events in the process of carcinogenesis in cervical and a subset of head and neck cancers. The expression of the viral oncoproteins E6 and E7 is essential in this process by inactivating the tumor suppressor proteins p53 and Rb, respectively, in addition to their interactions with other host proteins and regulation of …

Investigating Iron Metabolism In Subarachnoid Hemorrhage Patients, Alexander A. Maynard, Gardenia Pacheco

Williams Honors College, Honors Research Projects

Subarachnoid hemorrhage (SAH) is a stroke characterized by bleeding into the subarachnoid space of the brain, typically resulting in high mortality rate.⁸ Delayed cerebral ischemia (DCI), characterized by vasospasms induced arterial constriction, occurs in roughly one third of the surviving patients.²⁰ The development of DCI and neurodegeneration could be linked to metabolic pathology that occurs after SAH, specifically iron induced changes in redox status. The oxidized environment induced by iron has the potential to functionally affect the ferroxidase ceruloplasmin (Cp), which is linked to neurodegeneration.¹⁵ Global LC-MS based metabolomics data revealed alterations in metabolism in the CSF …

Cellular Mechanisms By Which Alcohol Promotes Hiv Protease Inhibitor-Induced Hepatotoxicity, Michael Hinton

Theses and Dissertations

CELLULAR MECHANISMS BY WHICH ALCOHOL PROMOTES HIV PROTEASE INHIBITOR-INDUCED HEPATOTOXICITY

Michael Hinton, B.S.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University

Virginia Commonwealth University, 2019

Major Director: Huiping Zhou

Professor, Department of Microbiology and Immunology

The development of highly-active-antiretroviral therapy(HAART) has allowed management of HIV and extended the lives of those infected. Alcohol abuse, which is very common in HIV-1 infected patients, is one of the most important co-morbid risk factors for liver injury and has been associated with the occurrence of serious metabolic syndrome and subsequent discontinuation …

Mechanisms Of Trinucleotide Repeat Instability During Dna Synthesis, Kara Y. Chan

Theses and Dissertations--Toxicology and Cancer Biology

Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a …

Mutations Of Fus Cause Aggregation Of Rna Binding Proteins, Disruptions In Protein Synthesis, And Dysregulation Of Nonsense Mediated Decay, Marisa Elizabeth Kamelgarn

Theses and Dissertations--Toxicology and Cancer Biology

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron death and subsequent muscle atrophy. Approximately 15% of ALS cases are inheritable, and mutations in the Fused in Sarcoma (FUS) gene contribute to approximately 5% of these cases, as well as about 2% of sporadic cases. FUS performs a diverse set of cellular functions, including being a major regulator of RNA metabolism. FUS undergoes liquid- liquid phase transition in vitro, allowing for its participation in stress granules and RNA transport granules. Phase transition also contributes to the formation of cytoplasmic inclusions found in the …