Cell Biology Commons^™

Determining The Origin Of Changing Β-Catenin Concentrations In Zebrafish Oocytes During Maturation, Nathan Pincus

Summer Research

During maturation, oocytes (immature eggs) progress from prophase I to metaphase II of meiosis, and a multitude of other cellular changes occur. β-catenin is a unique protein as it is involved in cell-cell adhesion when it is bound in plasma membrane complexes, and acts as a transcription factor when freed into the cytoplasm and allowed to move into the nucleus. β-catenin has been found to take part in signaling pathways such as the Wnt/β-catenin pathway, which inhibits β-catenin degradation, and subsequently regulates gene transcription. β-catenin has also been found to exist in distinct molecular forms depending on its role, which …

Performance Screening Of Chemostat Adapted Recombinant Zymomonas Mobilis Strains, Deirdre M. Beard, Nancy Dowe

STAR Program Research Presentations

Corn stover biomass can be pretreaed and hydrolyzed into soluble sugars to be fermented by microorganisms to ethanol. NREL has developed a recombinant bacteria Zymomonas mobilis 8b that metabolizes both five and six carbon sugars. During pretreatment, toxic inhibitors such as furfural and acetate are produced. NREL has made an attempt to adapt two sub-strains of Z. mobilis 8b to acetate and furfural by using a chemostat method. During the chemostat process, cultures were frozen back in glycerol and saved. In this study, those frozen cultures were revived and analyzed for performance in environments with varying concentrations of furfural and …

Expression Of Bik, A Pro-Apoptotic Protein, In Developing Zebrafish (Danio Rerio) Oocytes, Maggie Klee

Summer Research

I addressed the role of cell death (apoptosis) within the process of egg cell development in zebrafish, in vitro. Current data on the role of apoptosis in oocyte maturation of zebrafish are conflicting, and little is known about apoptosis regulation at the individual stages of oocyte development.

The importance of apoptosis will be determined by recording the relative expression of Bik, a key protein involved in the apoptosis pathway, between zebrafish oocytes that have been induced to mature and those that are left alone. Relative expression of Bik will be measured by Western blot. I expect that Bik expression, and …

The Process Of Autophagy In An In Vitro Model Of Myocardial Ischemia-Reperfusion Injury, Kadija Abounit

Wayne State University Dissertations

Autophagy has been implicated in the pathogenesis of myocardial ischemia-reperfusion (I/R) injury; however, it is not clear whether autophagy is beneficial or detrimental to cell survival. We hypothesized that autophagy is beneficial to cardiomyocytes during I/R and that the paucity of ATP may limit its occurrence. To test this hypothesis, we developed a model of ischemia (hypoxia) involving exposure of HL-1 murine atrial cardiomyocytes to two concentrations of oxygen (0.5% and 2.0%) and 2-deoxyglucose.

Hypoxia, irrespective of the oxygen concentration, caused a dramatic drop in cellular ATP and an increase in the phosphorylation of AMPK (an indication of energy starvation),. …

Mechanical Forces And Tumor Cells: Insight Into The Biophysical Aspects Of Cancer Progression, Indrajyoti Indra

Wayne State University Dissertations

Mechanical forces play an important role in the regulation of cellular behavior and physiological processes including adhesion, migration, proliferation, tissue repair, embryogenesis and development. In addition, a number of diseases including cancer, have been linked to changes in cellular and extracellular mechanical properties. However, whether a correlation exists between the progression of cancer towards metastasis and mechanical factors has not been clearly defined. Additionally, how a cell responds to changes in extracellular mechanical cues as it gains metastatic abilities is poorly understood. To address these questions, we have utilized a panel of murine breast cancer cell lines with progressive metastatic. …

Science For The Environment: Examining The Allocation Of The Burden Of Uncertainty, Elisa Vecchione

Elisa Vecchione

The aim of this paper is to review the basic literature on scientific uncertainty in its statistical paradigm in order to provide enlightenment on one pivotal facet of the precautionary principle, i.e. the allocation of the burden of proof to demonstrate that an activity is not harmful to the environment. The purpose is not to explain a new theory of statistical inference, but to show how regulatory policymaking that is properly informed by scientific expertise and designed to avoid one type of error, may actually make other errors more likely and thus expose the public to danger. This problem is …

Method For Somatic Cell Nuclear Transfer In Zebrafish, Kannika Siripattarapravat, Jose Cibelli

Jose Cibelli

Somatic cell nuclear transfer (SCNT) has been a well-known technique for decades and widely applied to generate identical animals, including ones with genetic alterations. The system has been demonstrated successfully in zebrafish. The elaborated requirements of SCNT, however, limit reproducibility of the established model to a few groups in zebrafish research community. In this chapter, we meticulously outline each step of the published protocol as well as preparations of equipments and reagents used in zebrafish SCNT.

Dead Zones In Porous Catalysts: Concentration Profiles And Efficiency Factors, Roger L. York, Kaitlin M. Bratlie, Lloyd R. Hile, Larry K. Jang

Kaitlin M. Bratlie

This paper examines the conditions under which a dead zone, or a portion of the catalyst devoid of reactant, can form in a porous catalyst in which simultaneous reaction and diffusion are occurring. The condition that allows for the existence of a dead zone is defined by a critical Thiele modulus. When the Thiele modulus - the ratio of chemical reaction to diffusion - is greater than the critical Thiele modulus, a dead zone exists. This dead zone can be mathematically defined by a change of boundary conditions. We examine nth order reactions in isothermal infinite slabs, infinite cylinders, and …

Mechanisms Of Yttrium Oxide Toxicity In Hek293 Cells, Sravanthi Bodapati

Theses, Dissertations and Capstones

As a non-metal oxide, yttrium oxide (Y2O3) nanoparticles have numerous applications in chemical synthesis, mechanical polishing and as additives to drugs, cosmetics, varnishes and food. Recent data have suggested that these particles are capable of inducing oxidative stress and cytotoxicity in human endothelial cell lines. To examine the potential mechanisms of yttrium oxide toxicity, human embryonic kidney (HEK293) cells were exposed to 1, 5, 10, 50 and 100 μM of Y2O3 nanoparticles for 12, 24, 36 or 48 hr. We hypothesized that exposure of HEK293 kidney cells to Y2O3 nanoparticles would be associated with increased evidence of intracellular oxidative stress …

Identification And Characterization Of Fkbp52-Specific Inhibitors For The Treatment Of Prostate Cancer, Johanny Tonos De Leon

Open Access Theses & Dissertations

Steroid hormone receptors require the ordered assembly of various chaperone and cochaperone proteins in order to reach a functional state. The final stage in the receptor maturation process requires the formation of a mutimeric complex consisting of Hsp90 dimer, p23, and one of several large immunophilins. Studies conducted previously demonstrated that the large immunophilin FKBP52 acts to potentiate glucocorticoid, androgen, and progesterone receptor signaling pathways. The aim of these studies was to identify and characterize FKBP52-specific inhibitors that would not only serve as tools for the pharmacological analysis of FKBP52-receptor interactions, but may also lead to novel drugs with significant …

An Apoptosis Targeted Stimulus With Nanosecond Pulsed Electric Fields (Nspefs) In E4 Squamous Cell Carcinoma, Wei Ren, Stephen J. Beebe

Bioelectrics Publications

Stimuli directed towards activation of apoptosis mechanisms are an attractive approach to eliminate evasion of apoptosis, a ubiquitous cancer hallmark. In these in vitro studies, kinetics and electric field thresholds for several apoptosis characteristics are defined in E4 squamous carcinoma cells (SCC) exposed to ten 300 ns pulses with increasing electric fields. Cell death was [95% at the highest electric field and coincident with phosphatidylserine externalization, caspase and calpain activation in the presence and absence of cytochrome c release, decreases in Bid and mitochondria membrane potential (Δψm) without apparent changes reactive oxygen species levels or in Bcl2 and Bclxl levels. …

Regulation Of Cell Adhesion Strength By Spatial Organization Of Focal Adhesions, Kranthi Kumar Elineni

USF Tampa Graduate Theses and Dissertations

Cell adhesion to extracellular matrix (ECM) is critical to various cellular processes like cell spreading, migration, growth and apoptosis. At the tissue level, cell adhesion is important in the pathological and physiological processes that regulate the tissue morphogenesis. Cell adhesion to the ECM is primarily mediated by the integrin family of receptors. The receptors that are recruited to the surface are reinforced by structural and signaling proteins at the adhesive sites forming focal adhesions that connect the cytoskeleton to further stabilize the adhesions. The functional roles of these focal adhesions extend beyond stabilizing adhesions and transduce mechanical signals at the …

Quantifying Agonist Activity At G Protein-Coupled Receptors, Frederick J. Ehlert, Hinako Suga, Michael T. Griffin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

When an agonist activates a population of G protein-coupled receptors (GPCRs), it elicits a signaling pathway that culminates in the response of the cell or tissue. This process can be analyzed at the level of a single receptor, a population of receptors, or a downstream response. Here we describe how to analyze the downstream response to obtain an estimate of the agonist affinity constant for the active state of single receptors.

Receptors behave as quantal switches that alternate between active and inactive states (Figure 1). The active state interacts with specific G proteins or other signaling partners. In the absence …

Nociceptin Signals Through Calcium In Tetrahymena Thermophila, Tom Lampert, Tom Bertagnoli, Nathanael Braun, Jon Forsberg, Breanne Gibson, Sharon Kobinah, Cheryl Nugent, Sarah Stevens, Heather G. Kuruvilla

Science and Mathematics Faculty Presentations

Tetrahymena thermophila are free-living, ciliated, eukaryotic organisms that respond to stimuli by moving toward chemoattractants and avoiding chemorepellents. Chemoattractant responses involve faster ciliary beating, which propels the organisms forward more rapidly. Chemorepellents signaling involves ciliary reversal, which disrupts forward swimming, and causes the organisms to jerk back and forth, swim in small circles, or spin in an attempt to get away from the repellent. Many food sources, such as proteins, are chemoattractants for these organisms, while a variety of compounds are repellents. Repellents in nature are thought to come from the secretions of predators, or from ruptured organisms, which may …

The Characterization Of Genes Involved In Response To The Phenol Derivative And Xenoestrogen Bisphenol-A In Saccharomyces Cerevisiae, Sasha N. Farina

CMC Senior Theses

Bisphenol A is an estrogenic compound that is found in polycarbonate plastics and epoxy resins; humans are continuously exposed to the compound and it is believed to possess the same carcinogenic effects as estrogen (Iso, 2006). In this study, I used Saccharomyces cerevisiae as a model organism to identify mechanisms by which BPA acts based on the genomic profiling of kinase genes from a Mat-α haploid deletion library. Kinases regulate many other proteins, so the identification of a single mutant could identify an entire affected pathway of genes. I conducted a systematic screen of these mutants using the phenotype of …

Escherichia Coli Fpg Glycosylase Is Nonrendundant And Required For The Rapid Global Repair Of Oxidized Purine And Pyrimidine Damage In Vivo, Brandy J. Schalow, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

Endonuclease (Endo) III and formamidopyrimidine-N-glycosylase (Fpg) are two of the predominant DNA glycosylases in Escherichia coli that remove oxidative base damage. In cell extracts and purified form, Endo III is generally more active toward oxidized pyrimidines, while Fpg is more active towards oxidized purines. However, the substrate specificities of these enzymes partially overlap in vitro. Less is known about the relative contribution of these enzymes in restoring the genomic template following oxidative damage. In this study, we examined how efficiently Endo III and Fpg repair their oxidative substrates in vivo following treatment with hydrogen peroxide. We found …

Stress-Induced Proteolysis Of Fkbp10: Mutational Analysis And Functional Implications, Lindsey A. Murphy

Featured Research

Cellular signaling is a complex system of communication that regulates cell function through a variety of molecular messengers. When cell survival is threatened by changes in environment or by malfunction of internal regulatory pathways, signals are initiated to restore homeostasis. Deficient protein processing within the endoplasmic reticulum (ER) causes an accumulation of misfolded proteins and stress signaling. The resulting stress signaling includes both adaptive signals (unfolded protein response) and in cases of severe ER stress apoptotic signals induced via the mitochondria. FKBP10 is a key ER luminal peptidy-prolyl isomerase (rotamase) that mediates protein folding. The production of chaperone proteins and …

Role Of Protein Kinase C-Iota In Neuroblastoma And The Effect Of Ica-1, A Novel Protein Kinase C-Iota Inhibitor On The Proliferation And Apoptosis Of Neuroblastoma Cells, Prajit P. Pillai

USF Tampa Graduate Theses and Dissertations

Protein Kinase C-iota (PKC-é), an atypical protein kinase C isoform manifests its potential as an oncogene by targeting various aspects of cancer cells such as growth, invasion and survival. PKC-é confers resistance to drug-induced apoptosis in cancer cells. The acquisition of drug resistance is a major obstacle to good prognosis in neuroblastoma. The focus of the dissertation was three-fold: First to study the role of PKC-é in the proliferation of neuroblastoma. Secondly, to identify the efficacy of [4-(5-amino-4-carbamoylimidazol-1-yl)-2,3-dihydroxycyclopentyl] methyl dihydrogen phosphate (ICA-1) as a novel PKC-é inhibitor in neuroblastoma cell proliferation and apoptosis. Finally, to analyze whether PKC-é could self-regulate …

Inhibition Of P53 Dna Binding Function By The Mdm2 Acidic Domain, Brittany Lynne Cross

USF Tampa Graduate Theses and Dissertations

MDM2 regulates p53 predominantly by promoting p53 ubiquitination. However, ubiquitination-independent mechanisms of MDM2 have also been implicated. Here we show that MDM2 inhibits p53 DNA binding activity in vitro and in vivo. MDM2 binding promotes p53 to adopt a mutant-like conformation, losing reactivity to antibody Pab1620, while exposing the Pab240 epitope. The acidic domain of MDM2 is required to induce p53 conformational change and inhibit p53 DNA binding. ARF binding to the MDM2 acidic domain restores p53 wild type conformation and rescues DNA binding activity. Furthermore, histone methyl transferase SUV39H1 binding to the MDM2 acidic domain also restores p53 wild …

Role Of Protein Kinase C-Iota In Glioblastoma, Shraddha R. Desai

USF Tampa Graduate Theses and Dissertations

The focus of this research was to investigate the role of protein kinase C-iota (PKC-é) in the regulation of Bad function, a pro-apoptotic member of the Bcl-2 family and Cdk7 function, a master cell cycle regulator in glioblastoma.

The results were obtained from the human glial tumor derived cell lines, T98G and U87MG. In these cells, PKC-é co-localized and directly associated with Bad as shown by immunofluorescence, immunoprecipitation, and Western blotting. Furthermore, in-vitro kinase activity assay showed that PKC-é directly phosphorylated Bad at phospho specific residues, S112, S136 and S155 which in turn induced inactivation of Bad and disruption of …