Cell Biology Commons^™

Thinking Beyond The Fried Egg Model: How Accurately Do Students Perceive Cells In A Living Context?, Milissa Knox

Electronic Theses and Dissertations

This exploratory study investigated three aspects of introductory undergraduate biology students’ understanding about cells. The study, which took place at the University of Maine with voluntary students in Basic Biology (“BIO100”) in the summer and fall of 2009, examined (1) students’ pre-course perceptions of cells as they exist in a living context and (2) gains in students’ perception and knowledge about cells after completing the one-semester course (BIO100). Results are based on lecture exam scores, pre-post surveys developed as a part of this thesis, and interviews with two groups of biology students. A total of 498 students participated in the …

The Role Of Tumor Suppressor Co-Chaperone Chip/Stub1 In Erbb2-Mediated Oncogenesis, Haitao Luan

Theses & Dissertations

The epidermal growth factor receptor (EGFR) family member ErbB2 (Her2) is overexpressed in 20 -30% of invasive breast cancers and this overexpression correlates with poor prognosis and shorter overall as well as disease-free survival. Aberrant expression of ErbB2 through gene amplification, transcriptional deregulation and/or altered endocytic trafficking results in overexpression of ErbB2 at the plasma membrane and biases ErbB2 from primarily ligand-driven hetero-dimerization under normal expression conditions to increased ligand-independent homo-dimer and hetero-dimer formation and consequent activation. C-terminus of HSC70-Inteeracting protein (CHIP)/STIP1-homologous U-Box containing protein 1 (STUB1) is an HSP90/HSC70 interacting negative co-chaperone known to promote ubiquitination and degradation of …

Acute Methamphetamine Exposure Affects Histone Modifying Enzymes And Cytokine Production In Macrophages, Ariel Burns

Theses & Dissertations

The effects of methamphetamine (Meth) in the periphery are not well studied and a comprehensive investigation on the effects and molecular mechanism will give insight into why Meth users are at an increased risk of infections. For this reason, we use macrophages as a model for the immune system dysregulation seen in Meth abusers and also because macrophages are a long-lived cell that HIV infects and persists in. We aimed to determine the effects of Meth on the cytokine production, histone modifying enzymes and the corresponding histone post-translational modifications, and the molecular mechanism in HIV-infected human macrophages treated with combination …

A Role For Ehd Family Endocytic Regulators In Endothelial Biology, Alexandra E. J. Moffitt

Theses & Dissertations

Endocytic trafficking is an essential process in eukaryotic cells, specifically for the transport of nutrients, membrane components, and receptors. Cargo destined for endocytic traffic is internalized at the cell surface via clathrin-dependent and clathrin-independent pathways, and brought to the early or sorting endosomes. From there, cargo is further trafficked to lysosomes for degradation, trafficked to other compartments in the cell, or recycled back to the cell surface (either directly or via the endocytic recycling compartment).

Mammalian C-terminal Eps15 homology domain-containing proteins, or EHD proteins (EHD1 to 4), are a family of highly conserved ATPases that function as key regulators of …

Investigation Of Cell-Penetrating Peptide Transformation In Two Regenerable Tissue Culture Systems, Atiyyah S. Ferouz

Electronic Thesis and Dissertation Repository

The genetic engineering of plants allows for the modification of plant genomes, subsequently improving plant traits. There are, however, plants recalcitrant to established transformation methods, requiring the implementation of novel techniques. This study investigates the viability of cell-penetrating peptide (CPP) transformation using Tat₂, a CPP with demonstrated transformation efficiency in plant and animal systems, in two regenerable tissue culture systems, soybean somatic embryos and Arabidopsis protoplasts. Assessments of complex formation, Tat₂ cellular translocation, complex uptake, and CPP-mediated transformation were carried out. The results show the formation of a Tat₂-plasmid complex and the uptake of Tat …

Hd2d Is A Regulator Of Abscisic Acid Responses In Arabidopsis, Joshua A. Farhi

Electronic Thesis and Dissertation Repository

Histone deacetylases have important roles in development and stress response in plants. To further investigate their function, the HD2D gene, of the plant specific HD2 family, was studied. An hd2d-1 mutant and two HD2D overexpression lines were used in this study. Germination was delayed in hd2d-1 and HD2D overexpression seeds only in the presence of ABA. HD2D was found to positively regulate the expression of members of the ABA-response pathway (ABI1, ABI5, and RD29A) leading to increased resistance to drought and salinity treatments. Furthermore, HD2D expression delayed flowering by positively regulating FLC expression. Using bimolecular fluorescence complementation, the HD2D protein …

Is The Zebrafish Zombie Mutant Caused By A Mutation In Cdc20?, Peyton Johnston

Honors Theses

The zombie mutant was identified as an early arrest mutant, stopping in development around the 10-somite stage (14 hours of development). Further inspection revealed that this mutant was a cell cycle mutant and cells in the mutant arrest during metaphase as early as the 5-somite stage (11.6 hours of development). A similar phenotype is seen in the Drosophila melanogaster cell cycle gene fizzy, known to be to be a homolog of the Saccharomyces cerevisiae gene, cell division cycle 20 (cdc20). CDC20 is an activator protein of the anaphase promoting complex/cyclosome (APC/C), an ubiquitin E3 ligase that is …

Brown And Beige Adipocytes: Effects Of Inflammation And Nutritional Intervention, Jiyoung Bae

Doctoral Dissertations

Recent findings of brown adipocytes and brown-like or beige adipocytes, capable of dissipating energy as heat, in adult humans have promised new hope for obesity treatment and prevention. Understanding of the regulation of brown and beige adipocytes will provide novel strategies to reach the goal. Pattern recognition receptors (PRR) are responsible for inflammation in adipose tissue, which leads to adipose dysfunction and obesity associated chronic diseases. It has been shown that PRR activation induces inflammation, leading to insulin resistance in white adipocytes and white adipose tissue (WAT). However, the roles of PRR activation in brown adipocytes and brown adipose tissue …

The Role Of G-Protein Signaling In Pathogenesis In Cercospora Zeae-Maydis, Brant Smith

Graduate Theses and Dissertations

Gray leaf spot, caused by Cercospora zeae-maydis, is one of the most destructive foliar diseases of maize worldwide. C. zeae-maydis orients hyphal growth towards stomata (stomatal tropism) and forms infectious structures (appressoria) that are necessary for successful infection. Although some genes involved in pathogenesis in C. zeae-maydis have been identified, the molecular mechanisms are not well understood. In fungi, heterotrimeric G-proteins consist of three subunits (α, β, and γ) and mediate responses to environmental stimuli. They regulate diverse functions, including nutrient detection, virulence, fungal development, conidiation, secondary metabolism, and pathogenesis in many plant pathogenic fungi. This research explored the role …

Eicosapentaenoic Acid (Epa) From Porphyridium Cruentum: Increasing Growth And Productivity Of The Microalgae For Pharmaceutical Products, Maryam Asgharpour

Graduate Theses and Dissertations

One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate …

Response Of Bacterial Cells To Fluctuating Environment, Sudip Nepal

Graduate Theses and Dissertations

We have studied morphological and genomic variations occurring in a mesophilic bacterium Escherichia coli (E. coli) in a wide range of continuous and fluctuating hydrostatic pressures. For all the studies here the temperature is maintained at 37◦C, the optimal growth tem- perature of E. coli at atmospheric pressure. Cell division is inhibited at high hydrostatic pressures resulting in an increase of cell length. The increase of cell-length depends on the extent and duration of the stress applied on bacterial cells. We have studied the effect of high pressure stress in three different conditions – (i) Wild-type cells (almost no genetic …

Role Of Stat3 In Human Nk Cell Functions, Prasad V. Phatarpekar

Dissertations & Theses (Open Access)

Natural Killer (NK) cells are cytotoxic lymphocytes, which play a critical role in the immune response against malignant cells and microbial infections. NK cells are equipped with activating receptors, which upon detecting ligands expressed on stressed cells induce cytolytic activity of NK cells. Stimulation of NK cell proliferation and priming of NK cytolytic capability are accomplished by cytokines, which mediate their signals mainly through JAK-STAT signaling pathway. Previously, we found that K562 cells genetically modified to express membrane bound IL-21 (mbIL-21), which predominantly activates STAT3, induce robust expansion and activation of human NK cells. Further investigations revealed role of STAT3 …

The Tumor Suppressor Notch Inhibits Head And Neck Squamous Cell Carcinoma (Hnscc) Tumor Growth And Progression By Modulating Proto-Oncogenes Axl And Ctnnal1 (Α-Catulin), Shhyam Moorthy, Shhyam Moorthy

Dissertations & Theses (Open Access)

Background: Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth most common malignancy worldwide, with roughly 300,000 cancer related deaths occurring globally each year. The survival of patients with HNSCC has not changed significantly over the past decade, leading investigators to search for promising molecular targets. To identify new treatment targets and biomarkers that could better guide therapy, we previously characterized the genomic alterations from primary HNSCC patient samples. We were among the first to discover that NOTCH1 is one of the most frequently mutated genes in this cancer type. The spectrum of inactivating NOTCH1 mutations in HNSCC suggested …

Preventing Thymus Involution In K5.Cyclin D1 Transgenic Mice Sustains The Naïve T Cell Compartment With Age, Michelle L. Bolner

Dissertations & Theses (Open Access)

The thymus maintains T cell receptor (TCR) repertoire diversity through perpetual release of self-MHC restricted naive T cells. However, thymus involution during the aging process reduces naïve T cell output, leading to defective immune responsiveness to newly encountered antigens. We have found that early thymus involution precipitates the age-associated shift favoring memory T cell dominancy in young control mice. Furthermore, we have shown that age-related thymus involution is prevented in mice expressing a keratin 5 promoter-driven Cyclin D1 (K5.D1) transgene in thymic epithelial cells (TECs). Thymopoiesis occurs normally in K5.D1 transgenic thymi and sustains T cell output to prevent the …

Molecular Regulation Of Vascular Calcification In Murine Models Of Atherosclerosis, Shanshan Gao

Dissertations & Theses (Open Access)

Background: Calcification occurs often in the atherosclerotic lesions of patients with coronary heart disease and animals with hypercholesterolemia, such as apolipoprotein-E deficient (ApoE-/-) mice. However, the mechanism(s) underlying the development of calcification in atherosclerosis remains unclear. ApoE acts as a lipid transporter, but also has been recognized as a potential regulator of osteogenesis. Little information is available as to whether ApoE has any direct impact on osteogenesis and calcification in vascular smooth muscle cells (VSMC). Several signal transduction pathways play a role in regulation of calcification, including the Wnt/β-catenin system and potentially GTAP, an ubiquitin-conjugating enzyme responsible for protein …

Leptin Regulates The Expression Of Autophagy-Related Genes In Chickens, Peter Olawale Ishola

Graduate Theses and Dissertations

Autophagy or cellular self-digestion, a lysosomal degradation pathway that is conserved from yeast to human, plays a key role in recycling cellular constituents, including damaged organelles. It also plays a pivotal role in the adaptation of cells to a plethora of distinct stressors including starvation. Autophagy has been extensively studied in mammals and yeast, but little is known in avian species. Thus, the major objective of the present study was to determine the effects of leptin on autophagy-related genes in chicken hypothalamus, muscle and liver. Leptin is an adipocytokine that is mostly produced by white adipose cells in mammals (as …

Transcriptomics Of Chicken Primordial Germ Cells, Nhung Thi Nguyen

Graduate Theses and Dissertations

Chicken primordial germ cells (PGCs) are derived from extraembryonic tissue of the embryo and first appear at stage X of development. They enter the bloodstream and migrate to the genital ridge, unite with somatic tissue to form a developing gonad, and then differentiate to sperm or ova (Fujimoto et al., 1976). Understanding molecular features of both male and female PGCs not only clarify the differentiation mechanism of such cells toward different germ lines, but will also help in selecting for highly productive types of commercial chicken. Most previous studies focused on the location of PGCs (Eyal-Giladi et al., 1981; Swift …

Characterization Of Embryonic Stem Cell-Differentiated Cells As Mesenchymal Stem Cells, Rachael N. Kuehn

Honors Theses

Embryonic stem cells (ESCs), due to their ability to differentiate into different cell types while still maintaining a high proliferation capacity, have been considered as a potential cell source in regenerative medicine. However, current ESC differentiation methods are low yielding and create heterogeneous cell populations. If transplanted in the human body, differentiated ESCs could be rejected by the immune system, form tumors, or may not function normally within the human body. On the other hand, mesenchymal stem cells (MSCs), a type of adult stem cell typically derived from bone marrow, have proved to be excellent candidates in clinical applications due …

The Effect Of Leucine Supplementation On Mitochondrial Biogenesis And Mitochondrial Protein Synthesis In Rats Fed A High-Fat Diet, David M. Skinner

Health, Human Performance and Recreation Undergraduate Honors Theses

This study aims to illuminate interaction between leucine supplementation and mitochondrial proteins concerned with synthesis and biogenesis. We hypothesized that supplementation with leucine will attenuate the weight gain of the high fat diet in comparison with the normal chow group, by enhancing mitochondrial biogenesis and content. We conducted a laboratory experiment using Western Blotting techniques to determine protein expression. Proteins of interest in this study include PGC-1α, COX-IV, TUFM, TFAM, and mtIF2. The findings from the research show a main effect of an increase in the expression of PGC-1 α in high fat diets. There was no difference in the …

Normal Glycolytic Enzyme Activity Is Critical For Hypoxia Inducible Factor-1a Activity And Provides Novel Targets For Inhibiting Tumor Growth, Geoffrey Grandjean Phd

Dissertations & Theses (Open Access)

Normal Glycolytic Enzyme Activity is Critical for Hypoxia Inducible Factor-1α Activity and Provides Novel Targets for Inhibiting Tumor Growth

By Geoffrey Grandjean

Advisory Professor: Garth Powis, D. Phil

Unique to proliferating cancer cells is the observation that their increased need for energy is provided by a high rate of glycolysis followed by lactic acid fermentation in a process known as the Warburg Effect, a process many times less efficient than oxidative phosphorylation employed by normal cells to satisfy a similar energy demand ^[1]. This high rate of glycolysis occurs regardless of the concentration of oxygen in the cell and …

Compounds Released From Biomass Deconstruction: Understanding Their Effect On Cellulose Enzyme Hydrolysis And Their Biological Activity, Angele Djioleu

Graduate Theses and Dissertations

The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in …

Hepatic Nutrient And Hormonal Regulation Of The Pancreatic-Derived Factor (Pander) Promoter, Whitney Ratliff

USF Tampa Graduate Theses and Dissertations

PANcreatic-DERived factor (PANDER, FAM3B) has been shown to regulate glycemic levels via interactions with both pancreatic islets and the liver. Although PANDER is predominantly expressed from the endocrine pancreas, recent work has provided sufficient evidence that the liver may also be an additional tissue source of PANDER production. At physiological levels, PANDER is capable of disrupting insulin signaling and promoting increased hepatic glucose production. As shown in some animal models, strong expression of PANDER, induced by viral delivery within the liver, induces hepatic steatosis. However, no studies to date have explicitly characterized the transcriptional regulation of PANDER from the liver. …

The Chemopreventive Effect Of Polymethoxyflavones: Targeting The Colorectal Cancer Stem Cells, Fei Xu

Doctoral Dissertations

Among all the cancers, the death rate of colorectal cancer is one of the highest. Evidence from both murine xenograft model and human trials have shown cancer stem cells (CSCs) are responsible for the initiation, metastasis and recurrence of multiple cancers therefore targeting colorectal CSCs would be a promising chemo-preventive/ therapeutic strategy. Polymethoxyflavones including nobiletin (NBT) and 5-demethylatednobiletin (5DN) are exclusively found in citrus peels and have been shown to have anti-cancer effects. Our previous studies in the biotransformation and tissue distribution of NBT and 5DN have shown that in order to fuller evaluate the biological impact of those two …

The Investigation Of Rhodiola Crenulata Root Extract Effects On Obesity Associated Inflammation And The Antineoplastic Mechanism In Breast Cancer Cells, Lotfi M. Bassa

Doctoral Dissertations

Obesity and breast cancer are two disease models that directly affect the United States population, as more than 35% of the adult population is obese [8], and more than 200,000 new cases of breast cancer are diagnosed in the United States per year [34]. Several diseases are associated with obesity including, cardiovascular disease, insulin resistance, increased inflammation and increased cancer risk [9,10]. Therefore it essential to understand the risks associated with obesity as well as to investigate possible preventive and/or therapeutic treatment strategies. Rhodiola crenulata is a Tibetan plant that has been used in Eastern traditional medicine to relieve depression, …

Mechanisms Of Neuroprotection Against Ischemic Insult By Stress-Inducible Phosphoprotein-1, Jason Xu

Electronic Thesis and Dissertation Repository

Stress-inducible phosphoprotein-1 (STI1) levels are increased in the brain following ischemia. STI1 is a co-chaperone for Hsp70/Hsp90 modulating protein folding. STI1 can also be secreted by a number of cells and function to activate extracellular signalling by the prion protein (PrP^C) and type-I bone morphogenetic protein receptor ALK2. However, the mechanisms by which STI1 can protect neurons against ischemia are currently unknown. A caspase-3 reporter mouse line was used to evaluate the consequences of increased extracellular STI1 levels. Neurons were treated with recombinant STI1 and specific agonists/antagonists for PrP^C, α7nAChR, and ALK2 prior to oxygen-glucose deprivation …

Characterization And Diurnal Measurement Of Oral Inflammation In Association With Glycemic Control, Periodontal Status, & Glucose Stimulation, Melanie N. Kuehl

USF Tampa Graduate Theses and Dissertations

Diabetes has afflicted 8.3%, approximately 25.8 million, of the United States population and is the seventh leading cause of death [1]. Type I diabetes (T1D) accounts for 5 to 10% of all diagnosed cases of diabetes in the United States [2]. If present trends continue, the rate of T1D incidence among children under the age of 14 will increase by 3% globally [3]. T1D is an autoimmune disorder in which the β-cells of the pancreatic islets are destroyed, leading to high blood sugar. Hyperglycemia and loss of immunological tolerance to self-antigens are common associations of T1D [4]. Periodontal disease impacts …

Dna Repair Deficiency In Huntington's Disease Fibroblasts And Induced Pluripotent Stem Cells, Peter Anthony Mollica

Biological Sciences Theses & Dissertations

Mutant huntingtin protein (mhtt)– the protein responsible for cellular dysfunction in Huntington’s disease (HD) –is a product of an expanded trinucleotide repeat (TNR) cytosine-adenine-guanine (CAG) sequence in exon 1 of the huntingtin (HTT) gene. The pathology of HD has been extensively researched; however, the mechanism by which the disease-causing TNR expansions occur in somatic cells remains elusive. Interestingly, HD has often been referred to a ‘DNA repair disease’, even though DNA repair dysfunction in situ has not been identified. We hypothesized that presence of the mhtt protein affects the expression of DNA repair genes used to address DNA repair, ultimately …

Biophysical Properties Of Cellular Membranes In Gram-Positive Bacterial Pathogens And Their Impact On Major Physiological Attributes And Virulence Determinants, Suranjana Sen

Theses and Dissertations

The cytoplasmic membrane of bacterial cells, forming an essential barrier from the surroundings, is a critical component of cellular physiology ensuring proper survival and maintenance of major cellular functions. The integrity of the membrane is an important feature that plays an essential role in the transport of solutes and nutrients through active and passive pathways, functions of membrane-associated proteins, electron transport and ATP synthesis, maintaining turgor pressure and combating environmental stresses, and thus is a crucial factor of a majority of cellular adaptations. The various biophysical properties affecting the integrity of this membrane are mainly determined by the composition and …

Application Of 3d Printing Technology In Porous Anode Fabrication For Enhanced Power Output Of Microbial Fuel Cells, Bin Bian

Electronic Thesis and Dissertation Repository

Microbial fuel cells (MFCs) are widely researched for application in wastewater treatment. However, the current anodes used in MFCs often suffer from high fabrication cost and uncontrollable pore sizes. In this thesis, three-dimensional printing technique was utilized to fabricate anodes with different micro pore sizes for MFCs. Copper coating and carbonization were applied to the printed polymer anodes to increase the conductivity and specific surface area. Voltages of MFCs with various anodes were measured as well as other electrochemical tests such as linear sweep voltammetry and electrochemical impedance spectroscopy. 3D copper porous anode produced higher maximum voltages and power densities …

Function Of Long Noncoding Rnas In Breast Cancer, Edward J. Richards

USF Tampa Graduate Theses and Dissertations

Breast cancer is a disease that will be diagnosed in about 1 in 10 women throughout their lifetime. The majority of breast cancers are originated from the epithelial cells of the mammary ducts, and this occurrence can be due to several factors including hereditary and acquired mutation. There are several major breast cancer subtypes, including estrogen receptor-α (ERα)-positive, HER2-enriched and triple-negative (TNBC). Patients diagnosed with ER+ tumors are generally treated with estrogen blockers (e.g., tamoxifen, letrozole and fulvestrant). Patients with HER2+ tumors are commonly administered with drugs that block HER2 signaling (e.g., trastuzumab) or inhibit HER2’s tyrosine kinase activity (e.g., …