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Theses/Dissertations

2009

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Articles 1 - 21 of 21

Full-Text Articles in Cell Biology

Characterization And Functional Regulation Of Bioactive Peptides In Avian Macrophages And Heterophils, Lakshmi Kannan Dec 2009

Characterization And Functional Regulation Of Bioactive Peptides In Avian Macrophages And Heterophils, Lakshmi Kannan

Graduate Theses and Dissertations

Oligopeptides and low molecular weight polypeptides play central roles as effectors and signal transducers acting as hormones, neurotransmitters, growth factors, toxins, and antimicrobial factors that are important for the survival of the organism. Owing to the ubiquitous involvement of peptides in many key regulatory processes, we have been interested to identify native peptides in different cells and tissues and understand their functions. To conduct our studies, we used avian macrophages and heterophils as models of specialized cells which constitute central components of innate immunity. These studies involved (a) qualitative identification and characterization of the peptides associated with high intensity mass …

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Identification Of A Conserved Cluster In The Rh Domain Of Grk Critical For Activation By Gpcrs, Faiza Baameur Dec 2009

Identification Of A Conserved Cluster In The Rh Domain Of Grk Critical For Activation By Gpcrs, Faiza Baameur

Dissertations & Theses (Open Access)

One of the most critical aspects of G Protein Coupled Receptors (GPCRs) regulation is their rapid and acute desensitization following agonist stimulation. Phosphorylation of these receptors by GPCR kinases (GRK) is a major mechanism of desensitization. Considerable evidence from studies of rhodopsin kinase and GRK2 suggests there is an allosteric docking site for the receptor distinct from the GRK catalytic site. While the agonist-activated GPCR appears crucial for GRK activation, the molecular details of this interaction remain unclear. Recent studies suggested an important role for the N- and C-termini and domains in the small lobe of the kinase domain in …

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The Role Of Multiple Ccaat-Binding Factors In Candida Albicans Gene Expression, Lashall Lynn Bates Dec 2009

The Role Of Multiple Ccaat-Binding Factors In Candida Albicans Gene Expression, Lashall Lynn Bates

Graduate Theses and Dissertations

The CCAAT-binding factor is a heterooligomeric transcription factor that is evolutionarily conserved in eukaryotes. In yeast, the DNA-binding component that interacts with the CCAAT consensus sequence in promoters consists of the subunits termed Hap2p, Hap3p and Hap5p. In yeast and fungi, a fourth subunit, Hap4p, is required for regulating gene expression. The goal of this research is to understand the function of the Candida albicans CCAAT-binding factor and how it relates to virulence and pathogenicity. C. albicans is a human opportunistic pathogen responsible for a variety of mucosal and systemic infections that result in significant morbidity and mortality, particularly in …

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Inhibition Of Pi 3-Kinase Signaling Contributes To Metronidazole Resistance In The Protozoan Parasite, Entamoeba Histolytica, Rhonda Powell Dec 2009

Inhibition Of Pi 3-Kinase Signaling Contributes To Metronidazole Resistance In The Protozoan Parasite, Entamoeba Histolytica, Rhonda Powell

All Theses

Amoebiasis is defined as an intestinal infection with the human protozoan parasite, Entamoeba histolytica; approximately 100,000 deaths annually can be attributed to amoebiasis. Disease states range from asymptomatic colonization to invasive amoebiasis, characterized by abdominal pain and dysentery. Dissemination to extraintestinal sites, such as the liver and/or brain, can occur. Vesicle trafficking is critical for parasite virulence, and multiple signaling cascades within the pathogen facilitate these events.
One important regulator of signal transduction is the tightly controlled PI 3-kinase (PI3K), which phosphorylates the lipid, phosphatidylinositol bisphosphate (PIP2), producing phosphatidylinositol trisphosphate (PIP3). Effector proteins, such as Akt, …

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The Role Of Human Endogenous Retroviruses In Renal Cell Carcinoma, Michele D. Tisdale Oct 2009

The Role Of Human Endogenous Retroviruses In Renal Cell Carcinoma, Michele D. Tisdale

Biological Sciences Theses & Dissertations

Human endogenous retroviruses make up approximately 8-9% of the human genome. A number of expressed HERVs, those that are actively transcribing, have been associated with various cancers. Suppression mechanisms that control HERV expression often fail or become more permissive in tissues where expression should be restricted. Previous studies have identified HERV expression in breast cancer tissues, whereas normal tissue HERV expression remained suppressed. In addition, studies of DNA hypermethylation have correlated with the ability to contribute to cancer development. Hypermethylation of several tumor suppressor genes occurs frequently in cancers and alterations in promoter regions could contribute to the development of …

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Delayed Anesthetic Preconditioning And Metallothioneins I+Ii: Novel Mediators Of Anesthetic-Induced Protection, Scott David Edmands May 2009

Delayed Anesthetic Preconditioning And Metallothioneins I+Ii: Novel Mediators Of Anesthetic-Induced Protection, Scott David Edmands

Open Access Dissertations

Ischemic injury is a common and debilitating outcome of natural illness and as a complication of commonly performed medical procedures. Whereas naturally occurring ischemic insults are often the result of unpredictable events, such as in the case of stroke or heart attack, the risk of operative and perioperative ischemia is somewhat better characterized in the clinical setting. Given the prevalence and severity of outcomes in ischemic injury, there is significant interest in developing better pharmacological and procedural approaches to improve patient outcomes. One approach that has shown significant promise in the laboratory setting, particularly in the context of planned medical …

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Modulation Of Macrophage Responses To Borrelia Burgdorferi In Acute Murine Lyme Carditis, Chris Martin Olson May 2009

Modulation Of Macrophage Responses To Borrelia Burgdorferi In Acute Murine Lyme Carditis, Chris Martin Olson

Open Access Dissertations

The Lyme disease spirochete Borrelia burgdorferi is the only known human pathogen that directly activates invariant natural killer T (iNKT) cells. The number and activation kinetics of iNKT cells vary greatly among different strains of mice. Here, we report the role of the iNKT cell response in the pathogenesis of Lyme disease using C57BL/6 (B6) mice, a strain with optimal iNKT cell activation that is resistant to the development of spirochetal-induced inflammation. During experimental infection of B6 mice with B. burgdorferi , iNKT cells localize to the inflamed heart where they are activated by CD1d-expressing macrophages. Activation of iNKT cells …

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The Conformational Gymnastics Of The Escherichia Coli Seca Molecular Machine And Its Interactions With Signal Sequences, Jenny Lynn Maki May 2009

The Conformational Gymnastics Of The Escherichia Coli Seca Molecular Machine And Its Interactions With Signal Sequences, Jenny Lynn Maki

Open Access Dissertations

Protein secretion is a selective and regulated process that is essential in all organisms. In bacteria the preprotein translocase SecA, either free in the cytosol or associated with the SecYEG translocon, recognizes and binds most post-translational secretory proteins containing an N-terminal signal sequence. In Gram-negative bacteria, the molecular chaperone SecB binds many of the preproteins to keep them in a translocation-competent state. Subsequently, SecB delivers the preproteins to the translocon-associated SecA, which binds the signal sequence and also interacts with mature regions of the preprotein. After the preprotein/SecA/SecYEG complex has formed, the energy derived from ATP hydrolysis by SecA coupled …

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Preparation, Separation, Purification, Characterization And Human Cell Line Anti-Cancer Evaluation Of Rice Bran Peptides, Arvind Kannan May 2009

Preparation, Separation, Purification, Characterization And Human Cell Line Anti-Cancer Evaluation Of Rice Bran Peptides, Arvind Kannan

Graduate Theses and Dissertations

Bioactive compounds are revolutionizing the nutritional and medicinal world with their inherent disease-fighting properties. A wide range of functional groups fall under the category of imparting health benefits. Compounds from both animal and plant origins have been generated as bioactive agents that have opened up new vistas for alternative medicine and natural healing. For example, in a debilitating disease like cancer, these compounds can act to suppress or delay the underlying pathology over and above the conventional treatment strategies involving drugs or chemotherapy. In other words conventional and invasive therapy, although still considered appropriate at certain stages of cancer, their …

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The Membrane Interface Of Chloroplast Signal Recognition Particle-Dependent Protein Targeting, Naomi Jane Marty May 2009

The Membrane Interface Of Chloroplast Signal Recognition Particle-Dependent Protein Targeting, Naomi Jane Marty

Graduate Theses and Dissertations

A novel signal recognition particle (SRP) found in the chloroplast (cpSRP) works in combination with the cpSRP receptor, cpFtsY, to facilitate the post-translational targeting of a family of nuclear-encoded thylakoid proteins to the Alb3 translocase in thylakoid membranes. Work here focused on understanding events at the membrane that take place to ensure targeting of the cpSRP-dependent substrate to Alb3. Specifically, we sought to understand the structural and functional role of membrane binding by cpFtsY, a protein that exhibits the ability to partition between the membrane (thylakoid) and soluble (stroma) phase during protein targeting. We also sought to understand whether a …

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Functional Interaction Of Racf2 And The Wasp Family Protein, Scar, In The Rab8 Signaling Pathway Of The Social Amoeba, Dictyostelium Discoideum, Terri Bruce May 2009

Functional Interaction Of Racf2 And The Wasp Family Protein, Scar, In The Rab8 Signaling Pathway Of The Social Amoeba, Dictyostelium Discoideum, Terri Bruce

All Dissertations

The small GTPase, Rab8, has been shown to play a role in cell-cell adhesion and restructuring of the actin cytoskeleton in both mammalian cells and the lower eukaryote, Dictyostelium discoideum. In D. discoideum, cells expressing constitutively activated Rab8 (Rab8CA) display reduced cell-cell adhesion and increased actin-rich protrusions as well as delayed aggregation. Rab8 has been implicated in the restructuring of the actin cytoskeleton, but no specific pathway for this action has been identified. In other systems, actin-rich membrane extension formation is regulated by WASp family proteins, including SCAR. Here we provide evidence of a functional relationship between the WASp family …

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Construction And Characterization Of A Novel Fusion Protein From The Extracellular Domain Of Mult1 And Transmembrane And Intracellular Domains Of Fas And Its Therapeutic Evaluation For Cancer Treatment Using An Adenoviral Delivery System, Hari Shankar Kotturi Rajeshwar May 2009

Construction And Characterization Of A Novel Fusion Protein From The Extracellular Domain Of Mult1 And Transmembrane And Intracellular Domains Of Fas And Its Therapeutic Evaluation For Cancer Treatment Using An Adenoviral Delivery System, Hari Shankar Kotturi Rajeshwar

All Dissertations

One of the strategies that tumor cells adopt to evade immunosurveillance mounted by elements of the innate immune system, such as NK cells, is to down-regulate certain cell surface molecules through a process also called shedding. Mouse UL16-binding protein-like transcript 1 (MULT1), which can activate NK cells through NK cell receptor NKG2D, is one of such molecules. Tumor cells can also avoid Fas mediated apoptosis by down-regulating its expression, secreting antagonistic `decoy' receptors, or expressing anti-apoptotic molecules. In this study, we report the design and evaluation of the antitumor activity of a novel fusion protein MULT1E/FasTI, consisting of the extracellular …

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Modeling Brain Injury: Expression Of Glial Fibrillary Acidic Protein In Stretch-Injured Astrocytes, Lindsey Cooke Apr 2009

Modeling Brain Injury: Expression Of Glial Fibrillary Acidic Protein In Stretch-Injured Astrocytes, Lindsey Cooke

Undergraduate Theses and Capstone Projects

Traumatic brain injury (TBI) is the leading cause of death and disability in individuals under 45. Individuals who survive TBI may be disabled for the rest of their lives and suffer from cognitive, physical, social and financial problems. Following TBI it has been shown that astrocytic gene expression of many proteins, including glial fibrillary acidic protein (GFAP), increases. These “reactive” astrocytes are thought to have both beneficial and detrimental effects on neuronal survival and function. The current study uses an in vitro model of injury which grows astrocytes on deformable silastic membranes to allow for dynamic stretch of cultured cells …

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Study Of The Dna Damage Complexes Within The Htlv-1 Tax Oncoprotein Interactome, Sidi Mehdi Belgnaoui Apr 2009

Study Of The Dna Damage Complexes Within The Htlv-1 Tax Oncoprotein Interactome, Sidi Mehdi Belgnaoui

Theses and Dissertations in Biomedical Sciences

Human T-cell leukemia virus type 1 (HTLV-1) is a transforming retrovirus that can give rise to adult T-cell leukemia (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). Tax is a virally encoded oncoprotein that is involved in HTLV-1 mediated cellular transformation. It has been hypothesized that Tax induces genomic instability via repression of the cellular DNA damage repair response. Our laboratory has previously shown that the interaction between Tax and various proteins involved in the DNA-damage response pathway impairs the ability of these proteins to mount an efficient repair response. As part of these observations, we proposed that Tax induces …

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Food Entrainment Of Circadian Gene Expression Altered In Pparα-/- Brown Fat And Heart, Brian Chun Kim Goh Mar 2009

Food Entrainment Of Circadian Gene Expression Altered In Pparα-/- Brown Fat And Heart, Brian Chun Kim Goh

Honors Theses

No abstract provided.

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Characterization And Differentiation Of Peripheral Blood Derived Multipotent Adult Progenitor Cells, Hari Satya Shankar Addagarla Jan 2009

Characterization And Differentiation Of Peripheral Blood Derived Multipotent Adult Progenitor Cells, Hari Satya Shankar Addagarla

Theses, Dissertations and Capstones

Stem cells are populations of undifferentiated cells that are found in most tissues and act as precursors for regeneration and maintenance. In the future, they could provide promising therapies for diseases which are to date incurable. Our lab developed a novel cell line from the peripheral blood of adult transgenic green fluorescent protein swine and designated them as Peripheral Blood Derived Multipotent Adult Progenitor Cells (PBD-MAPCs). In this study we characterized the mRNA and protein expression profiles of PBD-MAPCs before and after neural differentiation and investigated the potential of PBD-MAPCs to differentiate into myocardial or neural lineages in vitro. We …

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The Effect Of Exogenous Leptin On Murine Dendritic Cell Morphology And Function, Christine Delgado Jan 2009

The Effect Of Exogenous Leptin On Murine Dendritic Cell Morphology And Function, Christine Delgado

Open Access Theses & Dissertations

Leptin is a pleiotropic hormone primarily secreted by white adipose tissue. Although originally found to regulate food intake and energy expenditure, it is now known to also significantly affect the immune system. In this study we assessed the effect of leptin on bone marrow derived dendritic cell (BM-DC) cytoskeletal structure and functionality. Our preliminary data demonstrates that the addition of physiological concentrations of exogenous leptin to BM-DC causes cytoskeletal rearrangement specifically that of actin as evidenced by increased number of llamelopodia/dendrites and increased staining for actin within the llamelopodia/dendrite region. This suggests that leptin is a necessary component of DC …

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Protection Of Macrophages J774a.1 By Purine Nucleoside Analogues From Bacillus Anthracis Mediated Necrosis, Zadkiel R. Alvarez Jan 2009

Protection Of Macrophages J774a.1 By Purine Nucleoside Analogues From Bacillus Anthracis Mediated Necrosis, Zadkiel R. Alvarez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Eight years after the lamentable anthrax attacks, major scientific effort continues to be done, in order to stop imminent acts of bioterrorism. Innovative ways of therapy against the anthrax disease are being investigated. B. anthracis, the etiological agent of the infection, has a dormant stage in its life cycle known as the endospore. When conditions become favorable spores germinate, transforming into vegetative bacteria. In inhalational anthrax, the most fatal manifestation of the disease, spores enter the organism through the respiratory track, and are phagocytosized by alveolar macrophages of the lungs. Spores are able to sense nutrient availability, activating their germination …

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Live-Cell Studies On Mitotic Slippage In Humans, Daniela A. Brito Jan 2009

Live-Cell Studies On Mitotic Slippage In Humans, Daniela A. Brito

Legacy Theses & Dissertations (2009 - 2024)

Checkpoints are regulatory pathways that control the order and timing of specific cell-cycle events. In the presence of unattached/weakly-attached kinetochores, the mitotic checkpoint (MC) arrests cells in mitosis by inhibiting the degradation of cyclin B, the regulatory subunit of Cdk1 (cyclin dependent kinase 1). Checkpoints do not arrest cells permanently, and escaping mitosis with an unsatisfied MC requires cyclin B/Cdk1 inactivation. In yeast, this occurs through an “adaptation” mechanism involving inhibitory phosphorylations and/or Cdk1-inhibitors. To determine how vertebrate cells escape mitosis when the MC cannot be satisfied I conducted live-cell imaging and immunofluorescence studies on nocodazole-treated rat kangaroo (PtK) and …

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An Rnai Screen Targeting The Protein Tyrosine Kinases Identifies Bruton's Tyrosine Kinase (Btk) As A Breast Cancer Cell Survival Factor, Cheryl Lynne Eifert Jan 2009

An Rnai Screen Targeting The Protein Tyrosine Kinases Identifies Bruton's Tyrosine Kinase (Btk) As A Breast Cancer Cell Survival Factor, Cheryl Lynne Eifert

Legacy Theses & Dissertations (2009 - 2024)

The receptor protein tyrosine kinases (RPTKs) and the non- receptor protein tyrosine kinases (PTKs) are among the most commonly up-regulated genes found in all types of cancers. Although, a large body of data implicates a majority of tyrosine kinases (TKs) in cancer, few have been extensively evaluated for any potential therapeutic benefit in any of the many subtypes of breast cancer. We have used RNA interference (RNAi) to perform a large-scale loss-of-function analysis to facilitate the identification of individual factors necessary for the survival of an ErbB2 positive breast cancer cell line. We have found that 30% of the TKs …

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Pre-Mrna Splicing Manipulation Via Antisense Oligomers, Chalermchai Mitrpant Jan 2009

Pre-Mrna Splicing Manipulation Via Antisense Oligomers, Chalermchai Mitrpant

Theses: Doctorates and Masters

Duchenne muscular dystrophy (DMD), the most common lethal neuromuscular disease in childhood, arises from protein-truncating mutations in the dystrophin gene. A deficiency in dystrophin leads to loss of the dystrophin associated protein complex (DAPC), which in turn, renders muscle fibres vulnerable to injury, and eventually leads to muscle loss, necrosis and fibrosis. Although, the dystrophin gene was identified nearly two decades ago, and extensive research has been directed at finding a therapy for DMD, to date, there is still no effective treatment available. One promising molecular approach to treat DNID is antisense oligomer (AO) induced splice intervention. AOs were most …

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