Cell and Developmental Biology Commons^™

Dispersion Of Cytotoxic Properties Of Multi-Walled Carbon Nanotubes Suspended In Biological Solutions With Tween 80: Their Role In Enhancing Killing Effects Of Nanosecond Pulse Electric Fields On Tumor Cell Lines, Bhargava S. Kalluri

Biological Sciences Theses & Dissertations

The objective of this study was to determine whether multi-walled carbon nanotubes (MWCNTs) suspended in the surfactant Tween 80 give an additive killing effect on tumor cells when exposed to nsPEFs. In this study, MWCNTs were suspended in DMEM and RPMI with or without T80 (surfactant). The size distribution of MWCNTs suspended in these solutions was evaluated with a Delsa™ Nano Zeta potential and sub micro particle Size Analyzer and confirmed with microscopy. The cytotoxicity of MWCNTs dispersed in different concentrations of T80 was evaluated in PANC1 (Human pancreatic cancer cell line) and Jurkat cell lines (Human T-cell lymphoblast cell …

Activation Of P44/42 In Human Natural Killer Cells Decreases Cell-Surface Protein Expression: Relationship To Tributyltin-Induced Alterations Of Protein Expression, Fred D. Dudimah, Abraham Abraha, Xiaofei Wang, Margaret M. Whalen

Chemistry Faculty Research

Tributyltin (TBT) activates the mitogen activated protein kinase (MAPK), p44/42 in human natural killer (NK) cells. TBT also reduces NK cytotoxic function and decreases the expression of several NK-cell proteins. To understand the role that p44/42 activation plays in TBT-induced loss of NK cell function, this study investigated how selective activation of p44/42 by phorbol 12-myristate 13-acetate (PMA) affects NK cells. Previously it was shown that PMA caused losses of lytic function similar to those seen with TBT exposures. This study examined activation of p44/42 in the regulation of NK-cell protein expression and how this regulation may explain the protein …

The Biogeochemistry Of Submerged Coastal Karst Features In West Central Florida, Keith Michael Garman

USF Tampa Graduate Theses and Dissertations

West Central Florida is a complex karst environment with numerous sinkholes, springs, and submerged cave systems. Many of these karst features are anchialine, located within the subterranean estuary where freshwater and saltwater mix. Water quality data and/or fauna data were obtained from twenty-one karst features and their associated cave systems. The anchialine karst environment of the study area has a wide range of habitats with measured salinities ranging from freshwater at <0.2 ppt to sulfidic, hypersaline water at 38.5 ppt and measured pH readings ranging from 6.39 in water impacted by sulfur oxidizing bacteria to 10.3 in an isolated room of a cave. Stygobitic crustaceans were identified in conduits extending beneath the Gulf of Mexico supporting the hypotheses that freshwater crustaceans could survive higher sea levels in freshwater conduits beneath saltwater. The fauna associated with the anchialine cave systems included Sabellidae and Polychaeta worms, hydroids, cnidarians and hydrobiid snails. Jewfish Sink, like other anaerobic marine basins that were submarine springs, has four zones: oxic zone, transition zone, upper anoxic zone and anoxic bottom water. The upper zones have seasonal water quality variations from winter cooling and sinking of surface water and changes in the microbial communities. Activity of sulfate reducing bacteria is carbon limited in the anoxic zones, where sulfate reduction is the major metabolic process, and primary production is phosphate limited in the oxic zones. Organic input from the Gulf of Mexico drives the bacterial anaerobic ecosystem, resulting in a “sulfide pump”, in which sulfide percolates upward removing oxygen from the overlying sediment.

Identification Of An Archaeal Presenilin-Like Intramembrane Protease, Celia Torres-Arancivia, Carolyn M. Ross, Jose Chavez, Zahra Assur, Georgia Dolios, Filippo Mancia, Iban Ubarretxena-Belandia

Publications and Research

Background: The GXGD-type diaspartyl intramembrane protease, presenilin, constitutes the catalytic core of the c-secretase multi-protein complex responsible for activating critical signaling cascades during development and for the production of b-amyloid peptides (Ab) implicated in Alzheimer’s disease. The only other known GXGD-type diaspartyl intramembrane proteases are the eukaryotic signal peptide peptidases (SPPs). The presence of presenilin-like enzymes outside eukaryots has not been demonstrated. Here we report the existence of presenilin-like GXGD-type diaspartyl intramembrane proteases in archaea.

Methodology and Principal Findings: We have employed in vitro activity assays to show that MCMJR1, a polytopic membrane protein from the archaeon Methanoculleus marisnigri JR1, …

Cd277 Is A Negative Co-Stimulatory Molecule Universally Expressed By Ovarian Cancer Microenvironmental Cells, Juan R. Cubillos-Ruiz, Diana Martinez, Uciane K. Scarlett, Melanie R. Rutkowski, Yolanda C. Nesbeth, Ana L. Camposeco-Jacobs, Jose R. Conejo-Garcia

Dartmouth Scholarship

CD277, a member of the butyrophilin subfamily 3 (BTN3), shares significant sequence similarities and predicted common structural features with inhibitory B7-H4 and other members of the B7 superfamily. Here we report that CD277 is consistently expressed in stromal, as well as tumor cells in the microenvironment of human advanced ovarian carcinoma specimens, both of primary and metastatic origin. MHC-II+ myeloid antigenpresenting leukocytes (dendritic cells and macrophages) express significantly higher levels of surface CD277, compared to other tumor-infiltrating leukocyte subsets, and this expression is significantly up-regulated by multiple common tumor microenvironmental signals, including VEGF and CCL3. Most importantly, engagement of CD277 …

Repression Of Wnt Signaling By A Fer-Type Nonreceptor Tyrosine Kinase, Aaron P. Putzke

Biology Faculty Scholarship

The Wnt signaling pathway must be properly modulated to ensure an appropriate output: pathological conditions result from either insufficient or excessive levels of Wnt signal. For example, hyperactivation of the Wnt pathway is associated with various cancers and subnormal Wnt signaling can lead to increased invasiveness of tumor cells. We found that the Caenorhabditis elegans ortholog of the Fer nonreceptor tyrosine kinase, FRK-1, limits Wnt signaling by preventing the adhesion complex-associated β-catenin, HMP-2, from participating in Wnt-dependent specification of the endoderm during embryogenesis. Removal of FRK-1 function results in relocalization of HMP-2 to the nucleus of epidermal cells, and allows …

Distinct Macrophage Subpopulations Regulate Viral Encephalitis But Not Viral Clearance In The Cns, Christina D. Steel, Woong-Ki Kim, Larry Sanford, Laurie Wellman, Sandra Burnett, Nico Van Rooijen, Rochard P. Ciavarra

Biological Sciences Faculty Publications

Intranasal application of vesicular stomatitis virus (VSV) induces acute encephalitis characterized by a pronounced myeloid and T cell infiltrate. The role of distinct phagocytic populations on VSV encephalitis was therefore examined in this study. Ablation of peripheral macrophages did not impair VSV encephalitis or viral clearance from the brain, whereas, depletion of splenic marginal dendritic cells impaired this response and enhanced morbidity/mortality. Selective depletion of brain perivascular macrophages also suppressed this response without altering viral clearance. Thus, two anatomically distinct phagocytic populations regulate VSV encephalitis in a non-redundant fashion although neither population is essential for viral clearance in the CNS. …

Role Of Ampk In The Upregulation Of Steroidogenic Acute Regulatory Protein In The Zona Fasciculata Of The Adrenal Cortex, Adam Wesley Dayton

Theses and Dissertations

Cortisol is a glucocorticoid produced by the zona fasciculata (ZF) of the adrenal cortex. Traditionally, cortisol production and release was seen as being regulated strictly by adrenocorticotropic hormone (ACTH). While this is true of baseline cortisol levels and in response to acute mental stress, the picture is somewhat more complicated in other situations.Interleukin-6 (IL-6) contributes to the maintenance of cortisol levels in situations of prolonged immune or inflammatory stress. AMP activated protein kinase (AMPK) was investigated as a possible mediator of the action of IL-6 or as an independent actor in raising cortisol levels in response to hypoxemic or hypoglycemic …

Factors Affecting Cytoplasmic And Nuclear Structures Of Mouse Gametes And Embryos Using Immunocytochemistry Technique., Nooraain Hashim

Student Works (2010-2019)

Experiment 1 was conducted with the main objective to establish ICC technique for morphological analysis of the mouse oocytes and embryos in local laboratory. Several tests were conducted to achieve specific aims which included; a) to study efficacy of the available instruments and system for detecting fluorescence signals from mouse oocytes, b) to compare efficiency of improved methods to reveal oocyte morphology. Fluorescence images of the meiotic spindles, cortical granules and nuclear materials were compared between sample preparations methods. The results showed that the methods employed were reliable to be used for detecting the meiotic spindle, cortical granules and nuclear …

The Effects Of Growth Hormone In The Inner Ear Of Zebrafish (Danio Rerio) During Hair Cell Regeneration, Chia-Hui Lin

Masters Theses & Specialist Projects

Although deafness is a universal problem, effective treatments have remained elusive. In order to develop potential treatments, an overall understanding of the cellular process of auditory hair cell regeneration, which occurs in fish but not mammals, must be established. A previous microarray analysis and qRT-PCR validation of noise-exposed zebrafish showed that growth hormone (GH) was significantly upregulated during the process of auditory hair cell regeneration. Thus, GH may play an important role during hair cell regeneration. However, cellular effects of exogenous GH in the zebrafish auditory hair cell regeneration have not been examined after noise exposure. To understand the effect …

The Role Of Tyrosine Phosphorylation In The Functions Of The Tumor Suppressor Gprc5a, Xiaofeng Lin

Dissertations and Theses (Open Access)

The retinoic acid inducible G protein coupled receptor family C group 5 type A (GPRC5A) is expressed preferentially in normal lung tissue but its expression is suppressed in the majority of human non-small cell lung cancer cell lines and tissues. This differential expression has led to the idea that GPRC5A is a potential tumor suppressor. This notion was supported by the finding that mice with a deletion of the Gprc5a gene develop spontaneous lung tumors. However, there are various tumor cell lines and tissue samples, including lung, that exhibit higher GPRC5A expression than normal tissues and some reports by other …

Genetic Analysis Of The Function Of The Drosophila Doublesex-Related Factor Dmrt93b, Diana O'Day

Dissertations and Theses (Open Access)

DMRT (Doublesex and Mab-3 related transcription factor) proteins generally associated with sexual differentiation in many organisms share a common DNA binding domain and are often expressed in reproductive tissues. Aside from doublesex, which is a central factor in the regulation of sex determination, Drosophila possesses three different dmrt genes that are of unknown function. Because the association with sexual differentiation and reproduction is not universal and some DMRT proteins have been found to play other developmental roles we chose to further characterize one of these Drosophila genes. We carried out genetic analysis of dmrt93B, which was previously found to be …

Defining The Role Of Il-15 Trans-Presentation By Distinct Cell-Types During The Development And Homeostasis Of Natural Killer And Invariant Natural Killer T Cells, Eliseo F. Castillo

Dissertations and Theses (Open Access)

The immuno-regulatory functions displayed by NK and iNKT cells have highlighted their importance as key lymphocytes involved in innate and adaptive immunity. Therefore, understanding the dynamics influencing the generation of NK and iNKT cells is extremely important. IL-15 has been shown to provide a critical signal throughout the development and homeostasis of NK and iNKT cells; however, the cellular source of IL-15 has remained unclear. In this investigation, I provide evidence that the cell-type providing IL-15 to NK and iNKT cells via trans-presentation is determined by the tissue site and the maturation status of NK and iNKT cells. For NK …

Loss Of Gprc5a Enhances Survival In Normal And Malignant Lung Epithelial Cells By Eliciting Persistent Stat3 Activation Induced By Autocrine Lif, Yulong Chen

Dissertations and Theses (Open Access)

Signal transduction and activator of transcription 3 (Stat3) is activated by cytokines and growth factors in many cancers. Persistent activation of Stat3 plays important role in cell growth, survival, and transformation through regulating its targeted genes.

Previously, we found that mice with a deletion of the G protein-coupled receptor, family C, group 5, member a (Gprc5a) gene develop lung tumors indicating that Gprc5a is a tumor suppressor. In the present study, we examined he mechanism of Gprc5a-mediated tumor suppression. We found that epithelial cells from Gprc5a knockout mouse lung (Gprc5a^-/- cells) survive better in vitro in medium deprived …

Immune Recognition Of Self Nucleic Acids Driven By Endogenous Antimicrobial Peptides: Role In Autoimmunity, Dipyaman Ganguly

Dissertations and Theses (Open Access)

Innate immune recognition of extracellular host-derived self-DNA and self-RNA is prevented by endosomal seclusion of the Toll-like receptors (TLRs) in the dendritic cells (DCs). However, in psoriasis plasmacytoid dendritic cells have been found to be able to sense self-DNA molecules in complex with the endogenous cationic antimicrobial peptide LL37, which are internalized into the endosomal compartments and thus can access TLR9. We investigated whether this endogenous peptide can also interact with extracellular self-RNA and lead to DC activation. We found that LL37 binds self-RNA as well as self-DNA going into an electrostatic interaction; forms micro-aggregates of nano-scale particles protected from …

Artemis Interacts With The Cul4a Ubiquitin E3 Ligase Complex And Regulates The Cell Cycle Progression, Yiyi Yan

Dissertations and Theses (Open Access)

Artemis, a member of the SNM1 gene family, is one of the six known components of the non-homologous end joining pathway. It is a multifunctional phospho-protein that has been shown to be modified by the phosphatidylinositol 3-kinases (PIKs) DNA-PKcs, ATM and ATR in response to a variety of cellular stresses. Artemis has important roles in V(D)J recombination, DNA double strand breaks repair and damage-induced cell-cycle checkpoint regulation. The detailed mechanism by which Artemis mediates its functions in these cellular pathways needs to be further elucidated. My work presented here demonstrates a new function for Artemis in cell cycle regulation as …

Nherf1 – New Modifier Of Colorectal Cancer Progression, Yuho Hayashi

Dissertations and Theses (Open Access)

Colorectal cancer (CRC) develops from multiple progressive modifications of normal intestinal epithelium into adenocarcinoma. Loss of cell polarity has been implicated as an early event in this process, but the molecular players involved are not well known. NHERF1 (Na+/H+ Exchanger Regulatory Factor 1) is an adaptor protein with apical membrane localization in polarized epithelia. In this study, we tested our hypothesis that NHERF1 plays a role in CRC. We examined surgical CRC resection specimens for changes in NHERF1 expression, and modeled these changes in two- and three-dimensional (2D and 3D) Caco-2 CRC cell systems. NHERF1 had significant alterations from normal …

E2f1 And Tumor Suppression: The Role Of P21, Mirnas, And The Dna Damage Response, Regina L. Weaks

Dissertations and Theses (Open Access)

E2F1 is a multi-faceted protein that has roles in a number of important cellular processes including cell cycle regulation, apoptosis, proliferation, and the DNA damage response (DDR). Moreover, E2F1 has opposing roles in tumor development, acting as either a tumor suppressor or an oncogene depending on the context. In human cancer, E2F1 is often deregulated through aberrations in the Rb-p16INK4a-cyclin D1 pathway. In these studies we examined three mechanisms by which E2F1 might mediate its tumor suppressive properties: p21-induced senescence, miRNAs, and the DNA damage response. We found that E2F1 acts as a tumor suppressor in response to ras activation …

Role And Regulation Of Epha2 In Pancreatic Cancer, Pavel A. Levin

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cancer cause of death in the US. Gemcitabine is the first-line therapy for this disease, but unfortunately it shows only very modest benefit. The focus of the current study was to investigate the role and regulation of EphA2, a receptor tyrosine kinase expressed in PDAC, to further understand this disease and identify new therapeutic targets.

The role of EphA2 was determined in PDAC by siRNA mediated silencing. In combination with gemcitabine, silencing of EphA2 caused a dramatic increase in apoptosis even in highly resistant cells in vitro. Furthermore, EphA2 silencing was found …

Regulation Of Morphogenesis In Filamentous Fungi, Haoyu Si

School of Biological Sciences: Dissertations, Theses, and Student Research

One of the distinguishing features of fungal cells is their highly polarized model of growth. Both yeast cells and hyphal cells grow by cell surface expansion at specified cortical sites. Although the same general mechanisms are likely to be involved in controlling the establishment of hyphal polarity in budding yeast and filamentous fungi, it is noticeable that hyphal cells are organized in a fundamentally different manner to yeast dells. For example, hyphal cells organize formins, septins and actins at the division site while simultaneously retain the same machinery at the tip; whereas yeast cells undergo a transient period of isotropic …