Cell Biology Commons^™

Understanding The Effects Of Embryonic Hyperglycemia On Retinal Development And Maintenance, Kayla Titialii-Torres

Theses and Dissertations--Biology

Hundreds of millions of people are affected by diabetes worldwide. Whether they are diagnosed with prediabetes or Type I or II diabetes, there are a variety of mechanisms in the pathogenesis of diabetes. Diabetes is a disease which consists of recurring states of hyperglycemia that can be difficult to manage due to either lack of insulin production or improper utilization of insulin. While these mechanisms of action differ, complications induced by diabetes occur in both poorly regulated Type I and II. Common complications of diabetes include nerve damage, kidney damage, and eye damage. Eye damage specifically is called diabetic retinopathy …

The Role Of Protein Tyrosine Phosphatase Receptor Type F In Intestinal Homeostasis And Colorectal Cancer, Ashley T. Skaggs

Theses and Dissertations--Molecular and Cellular Biochemistry

Protein phosphorylation defines one of the most important regulatory mechanisms in cell signaling. PTPRF, protein tyrosine phosphatase receptor type F, belongs to the class I R2A subfamily of protein tyrosine phosphatases (PTP). The overall objective of this dissertation is to investigate the molecular mechanisms by which PTPRF regulates normal and cancer stem cells by controlling Wnt signaling.

Dysregulation of Wnt signaling promotes the initiation and progression of colorectal cancer (CRC). We first determined the functional important of PTPRF in regulating Wnt signaling in CRC. Combining cell culture, 3D tumor organoid and xenograft models, results from our study establish PTPRF as …

A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy

Theses and Dissertations--Molecular and Cellular Biochemistry

Toxoplasma gondii is an opportunistic, protozoan parasite of all warm-blooded animals, infecting roughly one-third of humans worldwide. Humans acquire infections by consuming T. gondii tissue cysts in undercooked meat or from oocysts shed in cat feces. Encysted parasites convert into rapidly growing tachyzoites that disseminate throughout the body, defining the acute phase of infection. Under host immune pressure, tachyzoites convert into bradyzoites that populate tissue cysts found in CNS or muscle tissue and persist for the lifetime of the host, defining the chronic phase of infection. Tissue cysts are responsible for transmission via carnivory, but also possess the ability to …

Development Of Novel Pyridazine Derivatives And Drug Delivery Systems Against Dengue, Janae A. Culmer

College of Graduate Studies: Theses & Dissertations

The lack of approved vaccines, medications and treatment regimens has significantly contributed to the rapid spread of mosquito-borne viruses such as Dengue and Zika virus. The complex immunopathology of these viruses presents limitations for the development and implementation of a definitive, safe and effective approach to combat infections.Previous research has demonstrated that vector control strategies such as the elimination of larval habitats, larviciding with insecticides, the use of biological agents and the application of adulticides have been unsuccessful in the reduction of viral transmission leading to the need for the continued development of antivirals. This research proposes an approach for …

Cell-Engineered Vesicles For Therapeutic Delivery And Immunomodulatory Applications, Khaga Neupane

Theses and Dissertations--Chemistry

Development of a new kind of drug delivery system (DDS) that could efficiently deliver therapeutics to the cell of interest would allow us to accomplish cell-specific drug delivery while eliminating systemic toxicity. Although nanocarriers including endogenously released extracellular vesicles (EEVs), liposomes, and small molecules seem to be promising drug delivery systems, biological challenges persist for their use in clinical applications. Here, we demonstrate nanovesicles engineered by fragmenting cellular membranes can be exploited as versatile DDSs for therapeutics delivery as well as immunomodulatory functions. Cell-engineered vesicles were produced by cavitating cells using nitrogen gas at high pressure followed by serial centrifugation. …

Comparison Of Free Versus Encapsulated Drugs On 3t3 Differentiation, Simon H. Friedrich, Gabriel Volpe

UROP Posters

The scope of this project was to design, synthesize and test targeted nanoparticles containing hydrophobic and hydrophilic drugs that promote browning in adipose tissue. For hydrophilic drugs the use of liposomes and their hydrophilic core is more useful than the PLGA nanoparticles which have hydrophobic cores. The inhibition of the FOXO1 pathway and modulation of autophagy in adipose tissue can promote browning of white adipose tissue, or an energy burning state where excess energy is burned as heat instead of stored in the cell. If successful, these drugs would offer an alternative treatment for obesity where changes to the patient's …

Elucidating The Role Of Kmt2d In Her2+ Breast Cancer, Emily Ma

Dissertations

Breast cancer is the second leading cause of cancer-related deaths among women in the US. Histone modifications are common epigenetic changes that have been implicated in several breast cancers, including HER2+ breast cancers. Current therapies, such as trastuzumab, block the HER2 receptor to reduce tumor growth. Unfortunately, HER2+ breast cancers have found ways to overcome these therapies, leading to tumor resistance, metastases, and poor survival outcomes. A better understanding of the underlying mechanisms contributing to HER2+ breast cancer resistance may lead to the discovery of novel therapeutic strategies to improve patient outcomes.One prognostic marker for poor survival in women with …

Identifying The Human Homologs Of Yeast Rab Proteins Ypt10 & Ypt11 And A Global-Scale Louse Endosymbiont Genome Variation, Nathaniel P. Smith

Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease that causes loss of upper and/or lower motor neurons, and currently has no treatment or cure available. Over 90% of cases occur spontaneously with unknown causes, highlighting the complexity of the disease, and only 10% of cases are linked to heritable genetic mutations. Numerous ALS-linked genes are conserved through evolution, and model organisms may therefore provide opportunities to understand disease pathology at a molecular or cellular level, proving instrumental in identifying therapeutic targets. ALS subtype 8 (ALS8) is caused by an autosomal dominant P56S mutation in the VAPB gene that …

Regulation Of Ppp1r15a (Gadd34) And Ppp1r15b (Crep) Mrna Expression And Localization In The Unfolded Protein Response, Krithika Giresh

University of the Pacific Theses and Dissertations

The failure to balance protein synthesis, folding, and degradation in the endoplasmic reticulum (ER) leads to the accumulation of unfolded proteins, leading to ER stress. Cells respond to this stress by activating a response signaling pathway known as the Unfolded Protein Response (UPR). One of the branches of the UPR induces the phosphorylation of eIF2α (Eukaryotic Initiation Factor 2) to attenuate global protein synthesis, allowing for a chance to clear misfolded and unfolded proteins. This phosphorylation of eIF2α is opposed by a phosphatase, containing a catalytic subunit, Protein Phosphatase 1, and a scaffolding protein, either GADD34 or CReP. Inhibition of …

Alternative Splicing Regulates The Innate Immune Response To Viral Infection, Luke A. White

Graduate Student Theses, Dissertations, & Professional Papers

Rift Valley fever virus (RVFV) is a mosquito-borne RNA virus that infects humans and livestock in sub-Saharan Africa and the Arabian peninsula, causing disease ranging from a mild flu-like illness to liver damage, blindness, hemorrhagic fever, death, and, especially in livestock animals, high rates of abortive pregnancies. There is no approved vaccine for RVFV, and as a disease with a high rate of spread that causes severe illness, it is listed as a Category A pathogen by the USA CDC. A better understanding of RVFV’s molecular virology will be instrumental to combating RVFV as climate change causes its mosquito host …

Determining Haplotype Specific X Chromosome Inactivation State And Related Epigenetic Features In Female X-Linked Genes, Ariah Dawn Mackie

Cal Poly Humboldt theses and projects

Females with heterozygous X-linked mutations are prone to pseudo-haploinsufficiency because random X chromosome inactivation (XCI) silences one of their two X chromosomes. A prior study explored the theory that reactivating the silenced healthy allele could be a treatment for pseudo-haploinsufficient females. The next step was to evaluate this approach in a clinically relevant stem cell model of the rare neurological disease CDKL5 Deficiency Disorder (CDD). It was necessary to validate X-inactivation state with respect to CDKL5 allele expression in one of these models. We explored CDKL5 allele expression in two populations of CDD female patient-derived induced pluripotent stem cells (iPSCs) …

An Antimicrobial Polydopamine Surface Coating To Reduce Biofouling On Telemetry Tags Used In Marine Conservation Practices, Ariana Smies

Dissertations, Master's Theses and Master's Reports

Satellite telemetry tags are used to track the migration patterns of large cetaceans. These tags penetrate the dermis and remain embedded in the underlying blubber tissue. As the dermis of cetaceans is host to a diverse microbiome, and it is impossible to clean the skin before implanting the devices, the potential for infection is increased when the tags penetrate through the skin. H₂O₂ is a potential antimicrobial agent that, in addition to showing broad-spectrum efficacy against gram-negative and gram-positive bacteria, can promote wound healing outcomes by promoting proliferative factors and peptides that protect against oxidative stress. However, …

A Study Of Cobalt (Iii) Oxide Nanoparticle Delivery Of Sirna Molecules Directed Against Signaling Intermediates Of The P2y2 Receptor, Rachel Blair Stroud

Graduate Theses/Dissertations

G protein-coupled receptors are evolutionarily ubiquitous sensors of extracellular signals, propagating intracellular signal cascades through heterotrimeric G proteins. P2Y₂ receptors are GPCRs which are activated by extracellular nucleotides to mediate signaling cascades via Gαq coupling. Many GPCRs are subject to a common mechanism for signal termination involving phosphorylation of the C-terminal tail followed by β-arrestin binding and subsequent endocytic internalization of the complex. This effect has been described for the P2Y₂ R in the 1321N1 astrocytoma cell line, and UTP-induced activation and desensitization profiles have been previously defined. There is need to develop molecular vehicles for safe and …

Fluorescence Probes For Bioimaging: Synthesis, Photophysical Properties And Applications, Mehrun Nahar Uddin

Dissertations

Fluorescent probes are a vital tool in the study of cell imaging. There are many types of fluorescent probes ranging from inorganic and organic nanoparticles to organic molecules. When used judiciously, they can help provide essential information on cellular structure and function. The introduction of two-photon microscopy has expanded the need for new probes, in particular near-infrared (NIR) absorbing and emitting fluorescent probes. The photochemical and photophysical properties of NIR probes play a crucial role in their effectiveness in cell imaging by both conventional and two-photon excitation (2PE) microscopy. In this research, the synthesis, photophysical properties, and two-photon absorption (2PA) …

Novel Biomarkers Of Ciliary Extracellular Vesicles Interact With Ciliopathy And Alzheimer’S Associated Proteins, Ashraf M. Mohieldin, Amal Alachkar, John R. Yates Iii, Surya M. Nauli

Pharmacy Faculty Articles and Research

Ciliary extracellular vesicles (ciEVs), released from primary cilia, contain functional proteins that play an important role in cilia structure and functions. We have recently shown that ciEVs and cytosolic extracellular vesicles (cyEVs) have unique and distinct biomarkers. While ciEV biomarkers have shown some interactions with known ciliary proteins, little is known about the interaction of ciEV proteins with proteins involved in ciliopathy and neurodegenerative disorders. Here, we reveal for the first time the protein-protein interaction (PPI) between the top five ciEVs biomarkers with ciliopathy and Alzheimer disease (AD) proteins. These results support the growing evidence of the critical physiological roles …

Induction Of Il19 Expression Through Jnk And Cgas-Sting Modulates Dna Damage–Induced Cytokine Production, Sara H. Small, E. Jessica Tang, Ryan L. Ragland, Yaroslava Ruzankina, David W. Schoppy, Rahul S. Mandal, M. Rebecca Glineburg, Zgjim Ustelenca, Daniel J. Powell, Fiona Simpkins, F. Bradley Johnson, Eric J. Brown

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Cytokine production is a critical component of cell-extrinsic responses to DNA damage and cellular senescence. Here, we demonstrated that expression of the gene encoding interleukin-19 (IL-19) was enhanced by DNA damage through pathways mediated by c-Jun amino-terminal kinase (JNK) and cGAS-STING and that IL19 expression was required for the subsequent production of the cytokines IL-1, IL-6, and IL-8. IL19 expression was stimulated by diverse cellular stresses, including inhibition of the DNA replication checkpoint kinase ATR (ataxia telangiectasia and Rad3-related protein), oncogene expression, replicative exhaustion, oxidative stress, and DNA double-strand breaks. Unlike the production of IL-6 and IL-8, IL19 expression was …

Usp11 And Usp7 Deubiquitinases Regulate Sprtn Auto-Proteolysis And Sprtn-Mediated Dna-Protein Crosslink Repair, Megan C. Perry

Theses & Dissertations

DNA repair pathways that recognize and remove damaged DNA are vital for maintenance of genomic stability and prevention of tumorigenesis. Conversely, these pathways may be robust in tumor cells, thus diminishing the anti-cancer potential of available therapies. DNA-protein crosslinks (DPCs) are particularly deleterious DNA adducts that occur when proteins become irreversibly covalently bound to the DNA. DPCs represent a diverse group of lesions, as any protein can be crosslinked to the DNA duplex by non-specific crosslinking agents like reactive aldehydes and radiation. Additionally, functional DNA-binding proteins such as topoisomerases may become permanently crosslinked to DNA ends by abortive enzymatic processes …

A Pkcα-Mediated Growth Suppressive Mek-Erk Signaling Axis In Intestinal Epithelial Cells, Navneet Kaur

Theses & Dissertations

Members of the protein kinase C (PKC) family of serine/threonine kinases are involved in regulation of fundamental cellular functions, including proliferation, differentiation, survival, migration, and transformation. Increasing evidence points to anti-proliferative and tumor suppressive role of PKCs. Our laboratory and others have reported that the classical PKC isozyme, PKCαnegatively regulates proliferation and tumorigenesis in the intestinal epithelium. Our laboratory has further determined that PKCα signaling induces a program of cell cycle withdrawal in intestinal epithelial cells that involves downregulation of the pro-proliferative proteins, cyclin D1 and Id1, and upregulation of the cyclin dependent kinase (CDK) inhibitor, p21^Cip1. Unexpectedly, …

Probing The Role Of Astrocytes In The Pathology Of Fragile X Syndrome With Human Stem Cells, Baiyan Ren

Theses & Dissertations

Fragile X syndrome (FXS) is an X-linked neurodevelopmental disorder related to intellectual disability and the most common monogenic cause of autism spectrum disorder. FXS is mainly caused by an expansion of CGG repeats in the 5’-untranslated region of fragile X mental retardation 1 (FMR1) gene, leading to the loss of expression of fragile X mental retardation protein (FMRP). Astrocytes are the most abundant glial cells in the central nervous system (CNS). Loss of FMRP in astrocytes has been found to contribute to structural and functional synaptic deficits in the Fmr1-KO mouse model. The contribution of human astrocytes, however, to the …

Molecular Mechanisms Of Aberrant Protein Glycosylation In Pancreatic Cancer Stemness And Metastasis, Frank Leon

Theses & Dissertations

A myriad of genetic and other abnormal changes underlies the aggressiveness and dissemination properties observed in pancreatic cancer (PC). Aberrant protein glycosylation is a commonly observed feature in PC. The modification of protein O-glycosylation is mediated by glycosyltransferases, which attach and sequentially elongate monosaccharides on Serine/Threonine (Ser/Thr) motifs. Aberrant glycosylation is recognized as an emerging hallmark of cancer where a disruption in normal glycosylation results in irregular O-glycans.

This dissertation research has investigated the consequences of aberrant protein glycosylation on stemness and enhancement of metastatic properties in pancreatic ductal adenocarcinoma (PDAC). Several publications have reported aberrant O-glycosylation increases in oncogenic …