Biology Commons^™

Characterization Of Histidine Decarboxylase In Drosophila Using An Internal Flag Epitope, Maxwell Mianecki

Masters Theses

Histamine is a neurotransmitter in arthropods and is responsible for synaptic transmission in vision, mechanosensation, temperature sensing and sleep cycle in Drosophila. Histamine is synthesized by the enzyme histidine decarboxylase (HDC). While histamine is detectable within tissues using current immunofluorescent labeling techniques, immunological approaches have not been successful for HDC itself, with both direct antibodies and terminal epitope tags determined to be ineffective. In order to avoid loss of the epitope tag through putative N-­‐ and C-­‐terminal proteolytic cleavage, known to occur for HDC in other organisms, an internal epitope tag that does not disrupt enzyme function was utilized. A …

Modulation Of Host Phosphatidylinositol Phosphates By Salmonella Effector Protein Sopb, Heather L. Piscatelli

Open Access Dissertations

Salmonella spp. are gram negative bacteria capable of infecting a number of eukaryotic hosts. In humans, Salmonella infection can range anywhere from acute gastroenteritis to typhoid fever which can oftentimes be fatal.Salmonella are facultative intracellular pathogens that have acquired the ability to enter non-phagocytic cells such as those lining the intestinal epithelium. Uptake into epithelial cells is mediated by the Salmonellapathogenicity island 1 (SPI1) encoded type III secretion system (T3SS), a needle-like complex composed of over 20 proteins that translocates effector proteins directly into the host cell cytosol. Salmonella possess a second type III secretion system encoded on …

Associated Behavioral, Genetic, And Gene Expression Variation With Alternative Life History Tactics In Salmonid Fishes, Ashley Chin-Baarstad

Open Access Dissertations

Individual differences in behavior can have potential fitness consequences and often reflect underlying genetic variation. My research focuses on three objectives related to individual level variation: 1) evaluating the innate behavioral variation within and between individuals, families, and progeny of different life-history types across time; 2) testing for differences in gene expression within the brain associated with this behavioral variation; and 3) using genetic polymorphisms to test for associations with ecotype, as well as population structure, in polymorphic populations. First, we evaluated the variation in a suite of ecologically relevant behaviors across time in juvenile progeny produced from crosses within …

Intranuclear Strain Measured By Iterative Warping In Cells Under Mechanical And Osmotic Stress, Jonathan T Henderson

Open Access Dissertations

The nucleus is a membrane bound organelle and regulation center for gene expression in the cell. Mechanical forces transfer to the nucleus directly and indirectly through specific cellular cytoskeletal structures and pathways. There is increasing evidence that the transferred forces to the nucleus orchestrate gene expression activity. Methods to characterize nuclear mechanics typically study isolated cells or cells embedded in 3D gel matrices. Often report only aspect ratio and volume changes, measures that oversimplify the inherent complexity of internal strain patterns. This presents technical challenges to simultaneously observe small scale nuclear mechanics and gene expression levels inside the nuclei of …

The Role Of The Novel Lupus Antigen, Acheron, In Moderating Life And Death Decisions, Ankur Sheel

Masters Theses

Programmed cell death (PCD) is a major regulatory mechanism employed during development and homeostasis. The term PCD was coined to describe the death of the intersegmental muscles (ISMs) of moths at the end of metamorphosis. The timing of ISM death in the Tobacco Hawkmoth, Manduca sexta, is regulated by a fall in the titer of the steroid molting hormone 20-hydroxyecdysone (20E) late on day 17of pupal-adult development. This triggers the release of the peptide hormone, Eclosion Hormone (EH), which mediates its effects via the secondary messenger cGMP. It has been previously demonstrated that ISM death requires de novo gene expression. …

Rapid Method Of Processing Sperm For Nucleic Acid Extraction In Clinical Research, Matthew K. De Gannes

Masters Theses

Background: Sperm contain highly compact nuclei, inhibiting DNA extraction using traditional techniques. Current methods extracting sperm DNA involve lengthy lysis and no means of stabilizing DNA, hindering clinical research.

Objective: We sought to optimize an efficient method of extracting high quality human sperm DNA.

Methods: Sperm from three volunteers were isolated using PureCeption. We tested 1) proteinase K with DNA/RNA Shield, 2) DTT and TCEP as reducing agents, 3) QIAshredder homogenization, and 4) stability of sperm DNA fresh (baseline) or after 4 weeks of storage at 4^OC in DNA/RNA Shield using modified Quick-gDNA MiniPrep. DNA was PCR amplified …

Serotonergic Signaling Pathways That Suppress Amyloid Beta In Mouse Models Of Ad, Jonathan Robert Fisher

All Theses and Dissertations (ETDs)

A diagnosis of Alzheimer's disease is one of the most devastating things one can hear. This terrible disease robs people of their ability to remember cherished events as their brains become riddled with beta amyloid plaques. Alzheimer's is especially terrifying because there currently are no effective treatments for slowing or stopping the disease. However, recent research has shown that plaque formation is correlated to concentrations of amyloid beta. This discovery suggests that limiting amyloid beta production could potentially halt the disease. One promising avenue for slowing amyloid beta production is serotonergic signaling.

This dissertation presents evidence for a direct sequence …

The Role Of Lactate Dehydrogenase B In Aerobic Glycolysis-Mediated Resistance To Ab Toxicity, Tyler Tam

Electronic Thesis and Dissertation Repository

Alzheimer’s disease is a progressive, neurodegenerative disorder characterized by the accumulation of amyloid β (Aβ) plaques in affected brain regions. Strong evidence indicates that Aβ exerts neurotoxic effects by promoting mitochondrial dysfunction and ROS production, leading to widespread oxidative damage and activation of pro-apoptotic mechanisms. Past investigations suggest that neuronal resistance to Aβ toxicity is partly mediated by a Warburg Effect-like metabolism, in which cells exhibit elevated glycolytic activity and lactate production, while limiting mitochondrial respiration. Elevated lactate dehydrogenase A (LDHA) activity, which catalyzes lactate production from pyruvate, has been demonstrated to counter Aβ-induced oxidative stress and neurotoxicity, however the …

Identification And Characterization Of Msab Gene Involved In Biofilm Formation And Virulence In Staphylococcus Aureus, Amelsaad Elbarasi

Master's Theses

Staphylococcus aureus is an important human pathogen that causes a wide variety of life-threatening infections ranging from minor skin and oral infections to severe infections, such as bacteremia, pneumonia, osteomyelitis, or endocarditis due to the presence and secretion of a large number of virulence factors that are controlled by global virulence regulators in complex networks. Furthermore, S. aureus infections have become a threat to public health because of their high potential to form biofilm, and their ability to resist a wide range of antibiotics has exacerbated further. Therefore, understanding the regulatory networks and developing a drug targeting these networks has …

Role Of Msaa Gene In Regulation Of The Msaabcr Operon And Biofilm Development In Staphylococcus Aureus, Ahmed Alzuway

Master's Theses

Staphylococcus aureus is an important human pathogen that causes wide variety of diseases ranging from chronic biofilm associated infection to acute life threatening infection such as bacteremia, pneumonia, osteomyelitis, or endocarditis, despite the progress with antibiotics used in the treatment of bacterial infections. Furthermore, increased use of prosthetic and indwelling devices in modern medical practices has led to increased infections due to S. aureus. Treating S. aureus infections have become difficult owing to its ability to resist most of the antibiotics; this problem is further exacerbated by ability of MRSA strains to form biofilms. Emergence of community-acquired methicillin resistance …

Zebrafish As A Model For Determining The Mechanisms Causing Deafness In Myh9-Related Disease, Luke David Spychalla

Theses and Dissertations

Approximately 1 in 500 infants are diagnosed with hearing loss, and about half of these cases can be traced to genetic defects. Several hundred genes have been implicated in deafness, including MYH9, which codes for the conventional motor protein non-muscle myosin IIA (NMIIA). Mutations in MYH9 lead to syndromic MYH9-related diseases, which include deafness as a variable symptom, as well as non-syndromic autosomal deafness DFNA17. Despite its identification as a deafness gene, the functions of MYH9 in ear development and hearing remain unknown. To study this role, we will use zebrafish as a model. Zebrafish offer significant advantages including established …

Strategies To Sensitize Bladder Cancer Cells To Small Molecule Inhibitors Targeting The Pi3k Pathway, Giovanni Nitti

Dissertations & Theses (Open Access)

After many years of cancer research, it is well accepted by the scientific community that the future cure for this disease lies in a personalized therapeutic approach. Anticipating therapeutic outcome based on the genetic signature of a tumor has become the new paradigm. The PI3K pathway represents an ideal target for bladder cancer, as many of the key proteins of this pathway are altered or mutated in this particular type of cancer. Several small molecule inhibitors have been developed to target this pathway, but their efficacy has been shown to be heterogeneous among different cell lines and mostly cytostatic but …

Key Residues Of Human Cytoplasmic Protein Tyrosine Phosphatase-A And -B For Substrate Binding And Specificity, Byunghyun Park

Open Access Theses

Reversible tyrosine phosphorylation plays an important role in signaling pathways that are essential for regulating cellular growth, differentiation and metabolism. Moreover, several human diseases such as diabetes, obesity and cancers are associated with the deregulation of protein tyrosine phosphatases (PTPs). Several studies provide evidence that PTPs not only contribute to cellular differentiation, but over-expression of these molecules also leads to transformation of non-transfomed cells as well. Based on these results, designing specific PTP inhibitors may ultimately function as potential therapeutic agents to treat various diseases including cancer, diabetes, and autoimmune diseases. EphA2 is a receptor tyrosine kinase which is hypo-phosphorylated …

Manipulating The Tumor Microenvironment For Therapeutic Benefit, Kate M. Bailey

USF Tampa Graduate Theses and Dissertations

The physical tumor microenvironment contributes significantly to carcinogenesis, cancer progression and metastatic dissemination. Two main components of the tumor microenvironment, hypoxia and acidosis, are present in nearly every solid tumor and act as powerful selection forces against the tumor. Hypoxia and acidosis promote tumor heterogeneity and contribute to chemotherapy and radiotherapy resistance. This dissertation interrogates methods to target the tumor microenvironment including two novel studies describing mechanisms of buffer therapy resistance and targeting tumor hypoxia with vasodilators to enhance the efficacy of a hypoxia activated prodrug, TH-302.

In the first study, mechanisms of buffer therapy resistance were identified and detailed. …

Natural And Exogenous Genome Editing In Wiskott-Aldrich Syndrome Patient Cells, Tamara J. Laskowski

Dissertations & Theses (Open Access)

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency disease characterized by thrombocytopenia, recurrent infections and increased autoimmunity. This disease is caused by mutations in the WAS gene (WAS) which encodes for the WAS protein (WASp), exclusively expressed in hematopoietic cells and required for proper platelet production and lymphoid cell function. Approximately 11% of patients with WAS exhibit a phenomenon called Somatic Revertant Mosaicism which is characterized by the presence of lymphocytes which naturally revert back to normal phenotype by restoring WASp expression. To date, the mechanisms of this naturally-occurring gene therapy remains poorly understood, and the full extent …

Characterization Of Ftsa-Ftsn Interaction During Escherichia Coli Cell Division, Kimberly.Busiek@Gmail.Com K. Busiek

Dissertations & Theses (Open Access)

Division of a bacterial cell into two equal daughter cells requires precise assembly and constriction of the division machinery, or divisome. The Escherichia coli divisome includes nearly a dozen essential cell division proteins that assemble at midcell between segregating sister chromosomes. FtsZ, a homolog of eukaryotic tubulin, is the first essential cell division protein to localize at midcell where it polymerizes into a ring-shaped scaffold (Z ring). Establishment of the Z ring is required for recruitment of downstream cell division proteins including FtsA, a cytoplasmic protein that tethers the Z ring to the inner membrane. Following localization of FtsA and …

Chemical Induced Hypoxia Differentially Affects Gene Expression In Human Neuronal Cells, Natasha V. Pavlichko

Seton Hall University Dissertations and Theses (ETDs)

Previously, our laboratory used desferoxamine (DFO), to generate hypoxic conditions (a low oxygen condition) which decreased human neuronal cell viability, but some cells still survived. These surviving neurons showed no morphological changes when compared to the non-treated group. However, the alteration of several intracellular events were detected, such as an increase of hypoxia inducible factor 1 (HIF-1) mRNA levels, a decrease of human mu opioid receptor (hMOR) message, and no change of human delta opioid receptor (hDOR) receptor message. Western blot analysis showed the Janus kinase (JAK)/ Signal Transducers and Activators of Transcription (STAT) pathway was activated and an increase …

Signaling Events During Extraembryonic Endoderm Differentiation, Jason Taek Ki Hwang

Electronic Thesis and Dissertation Repository

Mouse F9 cells differentiate into primitive endoderm (PrE) when treated with retinoic acid (RA) and into parietal endoderm (PE) following subsequent treatment with dibutyryl cAMP. Wnt6 is up-regulated in PrE cell, and although it is sufficient to induce differentiation by signaling through the canonical WNT/β-catenin pathway, the mechanism by which the Wnt6 gene is regulated is not known. In addition to WNT signaling, PrE differentiation is accompanied by an increase in reactive oxygen species (ROS). ROS have been implicated in regulating the canonical WNT/β-catenin signaling pathway through Nucleoredoxin (NRX), but whether they are sufficient to induce extraembryonic endoderm in vitro …

The Inflammatory Response To Acute Muscle Injury, Kevin O'Fallon

Doctoral Dissertations

The overall goal of this dissertation was to examine inflammatory and regenerative responses to acute skeletal muscle damage and to define molecular mediators of repair. Study I examined the effects of an oral anti-inflammatory supplement on exercise-induced muscle damage (EIMD) and systemic inflammation in a human model. Quercetin has been shown in animal and in vitro models to downregulate nuclear factor-kappa beta (NF-κB) nuclear transactivation and monocyte chemoattractant protein 1 (MCP-1) secretion, which regulate muscle regeneration and inflammatory signaling between muscle and immune cells after injury. Subjects ingested quercetin (N=15) or placebo (N=15) before and after performing 24 eccentric contractions …

Photobiostimulation In C. Elegans As A Model For Low Level Light Therapy, Michael J. Spoto, Daryl D. Hurd

Science Scholars

Low-Level Laser Therapy (LLLT) is a developing therapeutic technique that has been gaining recognition in the scientific community in recent years. Previous experiments performed in LLLT research projects have been primarily mammalian and cell culture based. These experiments have produced results showing accelerated tissue repair. In this experiment, we introduce a new model, Caenorhabitidis elegans, a free-living soil nematode, to be used in LLLT research by testing the effects of exposure of the organism to various wavelengths and intensities of light commonly used in LLLT. C. elegans was shown to respond to photobiostimulation when exposed to specific wavelengths of …

Vaccinia Virus Flll Mediated Expedition Of Tanapoxvirus Replication In Cell Culture, Yih Wen Goh

Masters Theses

Tanapoxvirus (TPV) produces large but slow-forming plaques as opposed to vaccinia virus (VACV) that forms similar large plaques but more rapidly. A number of genes were identified in VACV, inclucding FllL, A33R, A34R and A36R that contribute to the regulation of virus release and dissemination, and are particularly responsible for the induction of actin tails. Among them, TPV lacks homologs of the FllL and A36R genes. F11Lmediated inhibition of RhoA-mDia signaling was shown to enhance the microtubules dynamics and modulates the cortical actin that assisted in the release of progeny virus from infected cells. To understand the possible effects of …

Polymerase Alpha Components Associate With Telomeres To Mediate Overhang Processing, Raffaella Diotti

Dissertations, Theses, and Capstone Projects

Telomeres consist of TTAGGG repeats, which end with a 3' G-overhang and are bound by a six-protein complex, known as Shelterin. In humans, telomeres shorten at each cell division, unless telomerase is expressed and able to add telomeric repeats to the 3' G-overhang. However, for effective telomere maintenance, the DNA strand complementary to that made by telomerase must be synthesized. In this study, I focused on the Polα/primase complex, in particular the subunits p68 (POLA2, the regulatory subunit) and p180 (Polα, the catalytic subunit), and their potential roles at telomeres. I was able to detect p180, p68 and OBFC1, a …

Lipid Dependence In Ras-Driven Tumors, Darin Salloum

Dissertations, Theses, and Capstone Projects

Over past decade, metabolic alterations in cancer cells have received a substantial amount of interest. It had been established that cancer cells undergo a significant amount of metabolic alterations, and some of these alterations are similar to those in normal highly proliferative cells. However, it is becoming more apparent that many of the metabolic alterations are specific to particular oncogenic signaling pathways. Although altered metabolic machinery makes cancer cells more efficient at promoting growth when nutrients are supplied at the sufficient amounts, the dependency of cancer cells on particular metabolic reprogramming deems cancer cells susceptible to disruptions within metabolic network. …

Metabolic Checkpoints In Cancer Cell Cycle, Mahesh Saqcena

Dissertations, Theses, and Capstone Projects

Growth factors (GFs) as well as nutrient sufficiency regulate cell division in metazoans. The vast majority of mutations that contribute to cancer are in genes that regulate progression through the G1 phase of the cell cycle. A key regulatory site in G1 is the growth factor-dependent Restriction Point (R), where cells get permissive signals to divide. In the absence of GF instructions, cells enter the quiescent G0 state. Despite fundamental differences between GF signaling and nutrient sensing, they both have been confusingly referred to as R and therefore by definition considered to be a singular event in G1. Autonomy from …

Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski

Dissertations and Theses

In Escherichia coli, cell division is defined by the polymerization and constriction of a cytokinetic ring (Z ring) formed by FtsZ, a tubulin-like GTPase, at midcell. Division also involves the formation of a multi-protein complex at midcell known as the divisome. Several divisome proteins promote the assembly/disassembly processes of FtsZ, thereby exercising spatiotemporal control over division. Among FtsZ regulatory proteins are the FtsZ ringassociated proteins (Zap), which either directly or indirectly stabilize the Z-ring by increasing lateral interactions amongst FtsZ protofilaments in the Z-ring. ZapA-D are recruited during early cytokinesis and have overlapping functions in stabilizing FtsZ at midcell, but …

Dj-1 And Atp13a2: Two Proteins Involved In Parkinson’S Disease, Josephat M Asiago

Open Access Dissertations

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, affecting approximately 0.3% of the total U.S. population, and its prevalence increases with age. Two neuropathological hallmarks of PD are the loss of dopaminergic neurons in the substantia nigra pars compacta, a region in the midbrain involved in initiating and sustaining movement, and the presence of cytosolic inclusions called Lewy bodies (LBs) in various brain regions. LBs are enriched with fibrillar forms of the presynaptic protein &agr;-synuclein (aSyn). Two autosomal recessive genes implicated in familial PD are PARK9, encoding the P-type ATPase ATP13A2, a lysosomal ATPase; and …

Dephosphorylation Of Iqg1 By Cdc14 Temporally Regulates Actin Ring Formation, Daniel Patrick Miller

Masters Theses

"Cytokinesis is the final step in cell division when the cell separates the cytoplasm by contracting a ring composed of filamentous actin (F-actin) and type II myosin. Iqg1, an IQGAP family member, is an essential scaffolding protein in budding yeast (S. cerevisiae) required for actin recruitment to, and contraction of, the actomyosin ring. Actin is recruited by the calponin homology domain (CHD) in anaphase after Iqg1 is localized to the bud neck. Consensus sites for the cyclin-dependent kinase (CDK) Cdc28 were identified flanking the CHD. This led us to the hypothesis that phosphorylation of Iqg1 by Cdc28 negatively regulates actin …

Regulation Of Inositol Biosynthesis And Cellular Consequences Of Inositol Depletion: Implications For The Mechanism Of Action Of Valproate, Rania M. Deranieh

Wayne State University Dissertations

Inositol is a six-carbon cyclitol that is ubiquitous in biological systems. It is a precursor for the synthesis of numerous biologically important compounds, including inositol phosphates and phosphoinositides that are essential for cell function and viability. Inositol compounds play a role in membrane formation, gene regulation, signaling, regulation of ion channels, and membrane trafficking. Furthermore, inositol regulates hundreds of genes, including those involved in the biosynthesis of inositol and phospholipids. While transcriptional regulation of inositol biosynthesis has been extensively studied and well characterized, regulation of inositol biosynthesis at the enzymatic level has not been addressed. The current study shows that …

The Lipogenic Phenotype Of Her2/Neu-Positive Breast Cancer Cells, Jan Martin Baumann

Legacy Theses & Dissertations (2009 - 2024)

Recent work has shown that HER2/neu-positive breast cancer cells rely on a unique Warburg-like metabolism for survival and aggressive behavior. These cells are dependent on fatty acid (FA) synthesis, show markedly increased levels of stored fats and disruption of the synthetic process results in apoptosis. Supplementation of the growth media with physiological concentrations of saturated FAs induces cell death, whereas HER2-normal cells are not affected. This is particularly interesting in the context of new epidemiological data showing that a diet rich in saturated FAs is positively correlated with the development of HER2-negative disease, but not HER2/neu-positive disease.

Characterizing Dsrna Production In Virus-Infected Fish Cells, Amal Brek Aloufi

Theses and Dissertations (Comprehensive)

Viral dsRNA is produced by almost all viruses sometime during their replicative cycle. These viral nucleic acids are potent inducers of both innate and adaptive immune responses, and are therefore considered important immuno-modulators. Previous studies have shown that viruses produce dsRNA when replicating in mammalian cells; however, to date no one has demonstrated viral dsRNA production in virus infected fish cells. Therefore, the goal of this study is to investigate dsRNA production by fish viruses in fish cells, verifying production and performing initial characterization of the dsRNA molecules being produced. Three different rainbow trout cell lines were used in this …