Cell Biology Commons^™

Exploring Staphylococcus Aureus Host-Pathogen Interaction Using Proteomic Technologies, Emilee Marlene Elizabeth Mustor

USF Tampa Graduate Theses and Dissertations

Staphylococcus aureus deploys an arsenal of virulence effectors to remodel the host environment during infection, while simultaneously the host mounts an immune response to contain and eliminate this bacterium. This dynamic interplay defines the host-pathogen interface and shapes infection outcome. In this context, the secreted proteases represent a major arm of S. aureus pathogenesis, promoting bacterial persistence in the host by dismantling immune defenses, cleaving host signaling molecules and reshaping the host proteome. However, traditional substrate-by-substrate characterization cannot reveal the full scope of proteolytic activity occurring during infection. To address this, we developed Terminal Amine-Guanidination of Substrates-Charge Reversal (TAGS-CR), a …

An Fgfr-P53 Developmental Signaling Axis Drives Salivary Cancer Progression, Julia M. R. Billington

USF Tampa Graduate Theses and Dissertations

Mucoepidermoid carcinoma (MEC) is the most frequently occurring salivary gland malignancy.Here, we investigated transcriptomic profiles of human fetal and adult salivary glands and MEC tumors to assess programs involved in MEC progression. Molecular and genetic analyses revealed that MEC tumors and fetal salivary glands share proliferative and developmental gene expression profiles that implicate an FGFR-p53 signaling axis in salivary MEC progression. Based on these findings, we developed a genetically engineered mouse model of advanced MEC via targeted expression of the CRTC1-MAML2 oncogene in salivary ductal cells. Specifically, CRTC1- MAML2 expression combined with p53 dysregulation in salivary ducts rewires FGF signaling …

The Only Constant Is Change: The Role Of Genetic Diversification In Cancer And Beyond, Malgorzata Tyczynska Weh

USF Tampa Graduate Theses and Dissertations

Genetic diversification, the process by which genetic variation arises in a population, is fundamental to evolution by natural selection. Mutation, a central diversification process, fuels adaptation across species, including in cancer. Yet most new mutations are neutral or deleterious on cell fitness, raising the question of how mutation-driven adaptation persists. To explore this paradox, I developed a spatial agent-based model (ABM) in which population fitness emerges from individual cells acquiring mutations at varied rates and with diverse fitness effects. I evaluated model behavior across adaptive states, mutation rates, and distributions of fitness effects. The results show that high mutation rates …

Dnajb6: A Potent Dnajb Chaperone In Regulating Tau Proteostasis, Abigail R. Esquivel

USF Tampa Graduate Theses and Dissertations

Neurodegenerative diseases often feature the pathological buildup of misfolded proteins, and tau is a principal culprit in multiple tauopathies. One chaperone of emerging interest is DnaJB6b, a member of the Hsp40/DnaJ family, which exhibits potent anti-aggregation activity against several disease-related proteins. Recent investigations highlight its unique capacity to recognize and neutralize aggregation-prone forms of tau. DnaJB6b appears potent against multiple variants of tau and may be acting against tau, in part, by directing misfolded tau toward proteasomal clearance. The first lines of evidence come from systematic chaperone screens, where DnaJB6b repeatedly emerged as a strong suppressor of tau seeding. Further …

Determining The Role Of The Histone Demethylase Kdm5b In Microglial Reactivity To Ethanol, Jessica Wohlfahrt

USF Tampa Graduate Theses and Dissertations

Through their involvement in various processes such as phagocytosis of foreign materials and damaged cellular debris, regulatory factor release, and surveillance, the macrophages of the brain, microglia, maintain homeostasis within the central nervous system. These diverse microglial functions therefore require transition to a range of phenotypic states. The epigenetic regulation of this activity, especially through trimethylation of lysine 4 on histone H3, and its regulator, lysine demethylase (KDM)5B, is an emerging research area. KDM5B has been implicated in several diseases including cancer, inflammatory disorders, and alcohol use disorder (AUD), the latter being the focus of this dissertation project. Deep proteomic …

Selective Pericyte Recruitment To Ec-Lined Tubes, Vessel Assembly Enhancement Through Pericyte Timp-3 Induction, And Pericyte Tbx2 In Capillary Formation And Maturation, Ksenia Marilyn Yrigoin Kaluguina

USF Tampa Graduate Theses and Dissertations

Capillaries, the smallest blood vascular networks, are formed by narrow and elongated endothelial cell (EC)-lined tubes with associated pericytes anchored to the abluminal tube surface. Our laboratory demonstrated that dynamic interactions between ECs and pericytes during capillary tube network assembly are required for basement membrane matrix deposition and maturation. We have also shown that key EC-derived factors promote pericyte recruitment, proliferation, and pericyte-induced basement membrane formation during capillary assembly. In the first section, we aim to identify if vascular smooth muscle cells (VSMCs) respond to the same factors and have the same invasive ability as pericytes since they are both …

A Shield-Bearer’S Tale: Elucidating The Roles Of Estradiol And Choline In Mitigating Chemotherapy-Related Cognitive Impairment, Robert W. Botelho Jr.

USF Tampa Graduate Theses and Dissertations

Chemotherapy-Related Cognitive Impairments (CRCIs) are significant consequences of chemotherapy that affect a substantial portion of breast cancer survivors, potentially persisting long after treatment cessation. This series of studies investigated the neuroprotective roles of estradiol and choline against CRCIs induced by cyclophosphamide and doxorubicin (CYP/DOX), commonly known as Adriamycin/Cytoxan (AC) chemotherapy. Utilizing the MMTV-PyVT mouse model of breast cancer, this body of work spans several experimental studies, the first of which evaluates the impact of dietary choline supplementation on spatial memory and cholinergic function in tumor-bearing mice undergoing chemotherapy. The subsequent study tests whether impaired ovarian function and resulting reductions in …

Functional Studies Of Dcaf14 In Replication Fork Stability And Genome Integrity, Neysha Tirado-Class

USF Tampa Graduate Theses and Dissertations

The response to replication stress is critical for ensuring the stability of replication forks and preserving genome integrity. To aid this response, several factors are recruited to stalled replication forks to prevent irreversible collapse of the replication machinery. Replication fork proteomic analyses of stalled forks reveal enrichment of DCAF14, a component of the Cullin4-RING (CRL4) E3 ubiquitin ligase complex, that mediates replication fork protection by blocking nuclease-mediated digestion of nascent DNA. However, little is known about the molecular mechanism by which DCAF14 functions in the context of replication stress. Notably, loss of function mutations in DCAF14 are associated with a …

Androgen Drives Melanoma Invasiveness And Metastatic Spread By Inducing Tumorigenic Fucosylation, Qian Liu

USF Tampa Graduate Theses and Dissertations

Melanoma incidence and mortality rates are historically higher for men than women, with an estimated ~47% more new cases and twice the lethality in men in the US in 2023. Consistent with these discrepancies, emerging studies have highlighted the tumorigenic role of the male sex hormone androgen and its receptor (AR) in promoting melanoma aggressiveness. However, underlying cellular and molecular mechanisms and their precise pathological contributions are not well-defined. We recently discovered a sex-associated disparity in melanoma fucosylation, the post-translational modification of proteins with the dietary sugar L-fucose. Fucosylation, the conjugation of fucose moieties onto different glycan linkages on target …

Novel Roles Of The Blm Syndrome Dna Helicase In Genome Maintenance And Mitochondrial Regulation, Brian B. Rodemoyer

USF Tampa Graduate Theses and Dissertations

Bloom syndrome (BS) is an extremely rare autosomal recessive genetic disorder caused by defects in the BLM gene. Patients with BS display a broad phenotypic spectrum including abnormally short stature, microcephaly, sun sensitivity, insulin resistance, perpetual oxidative stress, and a ~300-fold greater propensity for developing cancer than the general population. As such, BS patients typically do not live past their 20’s. The BLM gene encodes the BLM helicase, a member of the highly conserved RecQ family of 3’ to 5’ DNA helicases. Most of our cellular understanding of BLM is through its role in DNA damage repair through the homologous …

Exploring Strain Variation And Bacteriophage Predation In The Gut Microbiome Of Ciona Robusta, Celine Grace F. Atkinson

USF Tampa Graduate Theses and Dissertations

Current microbiome studies have shown that the maintenance of homeostasis betweenmicrobial populations (e.g. bacteria, viruses) and the host immune system (e.g. innate immune molecules) is necessary for balancing health and disease outcomes within the host. These studies most often utilize vertebrate models; however, research in this field can benefit from diverse model systems that facilitate our ability to conduct experiments to identify phylogenically conserved rules influencing homeostasis in the gut of animals. The Dishaw has developed the use of a filter-feeding marine invertebrate chordate, Ciona robusta, to model such fundamental interactions[1]–[6]. While most biological diversity and functional contribution within microbiomes …

Regulation Of The Heat Shock Response Via Lysine Acetyltransferase Cbp-1 And In Neurodegenerative Disease In Caenorhabditis Elegans, Lindsey N. Barrett

USF Tampa Graduate Theses and Dissertations

The decline of proteostasis is a hallmark of aging that is, in part, affected by the dysregulation of the heat shock response (HSR), a highly conserved cellular response to proteotoxic stress in the cell. The heat shock transcription factor HSF-1 is well-studied as a key regulator of proteostasis, but mechanisms that could be used to modulate HSF-1 function to enhance proteostasis during aging are largely unknown. In this study, we examined lysine acetyltransferase regulation of the HSR and HSF-1 in C. elegans. We performed an RNA interference screen of lysine acetyltransferases and examined mRNA expression of the heat-shock inducible gene …

Defining And Modeling Pericyte-Induced Capillary Network Assembly, Capillary Regression Preceding Pericyte-Stimulated Fibrosis, And Lymphatic Capillary Regression, Scott Stephen Kemp

USF Tampa Graduate Theses and Dissertations

Capillary formation and maturation can only occur through a series of highly orchestrated events that requires the coordinated efforts of both endothelial cells (ECs) and pericytes. While ECs are perfectly capable of creating tube networks on their own, the maturation and stabilization of these tube networks require the presence of a second cell type, pericytes, to create stable capillary networks. Previous studies have identified factors required for pericyte recruitment to EC tube networks, however, we hypothesized that there were still unaccounted for EC-derived molecules that were contributing to pericyte recruitment. In the first part of this study, we used serum-free, …

Defining The Role Of Oxidized Mitochondrial Dna In Myelodysplastic Syndromes, Grace Anne Ward

USF Tampa Graduate Theses and Dissertations

Myelodysplastic Syndromes (MDS) are heterogeneous bone marrow (BM) failure malignancies characterized by constitutive innate immune activation, NLRP3 inflammasome (IFM) driven pyroptotic cell death, and the induction of interferon-stimulated genes (ISG). MDS often diagnostically resembles other hematologic disorders, as such, additional tools are needed for the discrimination from overlapping disorders. We observed that oxidized mitochondrial DNA (ox-mtDNA) is released upon cytolysis. We hypothesize that levels of ox-mtDNA are high in MDS, allowing us to use it as a diagnostic biomarker; and that cell free ox-mtDNA is contributing to feedforward BM failure.

ROC/AUC analysis demonstrated that ox-mtDNA is a sensitive and specific …

The Role Of Eicosanoid Metabolism In Mammalian Wound Healing And Inflammation, Kenneth D. Maus

USF Tampa Graduate Theses and Dissertations

Inflammatory wounds, both chronic and acute, lead to increased morbidity and mortality rates, especially in the elderly population. The annual healthcare cost for chronic wound care alone is over $39B in the US and the demographic of susceptible patients is steadily increasing due to an aging population and lifestyle-related diseases (e.g., hyperlipidemia, obesity, and type 2 diabetes). In fact, many chronic wounds currently have a worse 5-year outlook than certain types of cancers. This shows the need for expediting the wound healing process in such a way that compresses inflammatory signaling and encourages wound resolution without sacrificing pathogen removal and …

Impact Of Arginine Metabolism And Sensing In Mouse Models Of Alzheimer’S Disease, Chao Ma

USF Tampa Graduate Theses and Dissertations

Alzheimer’s disease (AD) remains the most common neurodegenerative disease in the central nervous system (CNS), with amyloidosis and tauopathy as their two main hallmarks. Typical AD pathologies include cerebral plaques deposited by amyloid-β, neurofibrillary tangles aggregated by tau, and neuroinflammation caused by activated brain myeloid cells. A critical theme is centered on impaired brain metabolism. Emerging evidence showed that impaired arginine metabolism was a novel biomarker pathway for AD. The manipulation of arginine metabolism by a critical enzyme arginase 1 (ARG1) in neurons indicated therapeutic benefits in alleviating tau pathology. Balanced cellular proteostasis was governed by the mechanistic target of …

Adrenergic Modulation Of Precursor Cells Of Ovarian Cancer, Sweta Dash

USF Tampa Graduate Theses and Dissertations

Ovarian cancer remains one of the most lethal gynecological cancer and ranks eighth in cancer-related mortality among women. The high mortality rate can be attributed to majority of the cases being diagnosed at advanced stages of the disease when the survival rate and overall prognosis are poor. There is lack of effective screening modalities to detect ovarian cancer at early stages. Hence, a better understanding of the molecular mechanisms leading to ovarian cancer initiation is required.

Epidemiological studies have reported that conditions which cause chronic behavioral stress are associated with a higher risk of developing ovarian cancer. The activation of …

Determining The Role Of Dendritic Cells During Response To Treatment With Paclitaxel/Anti-Tim-3, Alycia Gardner

USF Tampa Graduate Theses and Dissertations

Intratumoral CD103+ dendritic cells (cDC1) are required for anti-tumor immune responses. In tumors that are poorly responsive to immunotherapeutic approaches targeting T cells, targeting cDC1 represents an alternative approach that may be useful in improving patient response rates. As such, it is critical to understand cDC1 function within tumors, and what may be preventing optimal function of cDC1. TIM-3 is a receptor that is highly expressed by cDC1 in murine and human mammary tumors, and TIM-3 blocking antibodies are currently being evaluated in clinical trials for a number of solid and hematological malignancies. In order to best design combinatorial therapeutic …

Characterizing The Impact Of Postharvest Temperature Stress On Polyphenol Profiles Of Red And White-Fruited Strawberry Cultivars, Alyssa N. Smith

USF Tampa Graduate Theses and Dissertations

All living organisms have developed mechanisms that help them prevent internal stress and survive under harsh conditions. For fruits, specifically strawberries, stress is fought against primarily by increasing the synthesis of polyphenols, which are secondary plant metabolites with bioactive activity. Characterizing these bioactive compounds and the differences between strawberry cultivars can be vital for strawberry breeders. Furthermore, understanding the mechanisms that trigger the synthesis of polyphenols and their levels within different strawberry cultivars will provide breeders with tools to successfully identify cultivars with higher resistance to pre- and postharvest stressors. To gain that understanding, this study aimed to characterize the …

The Role Of Cpeb2 Alternative Splicing In Tnbc Metastasis, Shaun C. Stevens

USF Tampa Graduate Theses and Dissertations

Breast cancer is the second leading cause of cancer-related deaths for women in the U.S. Although the overall 5-year survival rate for breast cancer is 90%, this rate drops substantially for triple-negative breast cancer (TNBC) due to its high metastatic potential. Furthermore, there is a lack of targeted therapeutics for TNBC, and clinical trials have been largely unsuccessful. These characteristics validate the need for identifying novel therapeutic targets for the treatment of TNBC. The study of alternative splicing (AS) has emerged as a powerful tool to elucidate the molecular underpinnings driving cancer.

Our lab has identified cytoplasmic polyadenylation element-binding protein …

Investigation Of An Alternative Protocol For The Production Of Sars-Cov-2 Antigenic Proteins, Nichole Ninaltowski

USF Tampa Graduate Theses and Dissertations

With the COVID-19 pandemic showing no signs of slowing down, large-scale antigenic protein production is still needed for surveillance using serologic assays. From screening to vaccines to biotherapeutics, being able to produce the proteins for these assays is essential; however, the current gold standard method for producing SARS-CoV-2 spike proteins is prohibitively expensive for most research groups.

Alternative methods of transfecting mammalian cells to produce recombinant proteins that are relatively inexpensive have been used for years. Unlike the expensive, commercially available lipid-based methods, other established methods such as polyethyleneimine (PEI), are considerably easier, and cheaper to meet the needs of …

The Multifaceted Role Of Ccar-1 In The Alternative Splicing And Germline Regulation In Caenorhabditis Elegans, Doreen Ikhuva Lugano

USF Tampa Graduate Theses and Dissertations

The Cell Division Cycle and Apoptosis Regulator (CCAR) family members are an enigmatic family of proteins regulating metabolism, cancer, apoptosis, DNA damage, and stress. Mammals have CCAR family members, CCAR1 and CCAR2/DBC1, which evolved from the founding family member CCAR-1/LST-3 expressed in Caenorhabditis elegans. Several studies have shown the importance of understanding these proteins' function in standard and altered physiological processes. Our studies aim to understand the genome-wide alternative splicing and germline regulation of Caenorhabditis elegans CCAR-1 in normal and heat shock conditions. Recently, mammalian CCAR family member CCAR2/DBC1 regulates the alternative splicing by forming a complex with ZNF326. This …

Cytoplasmic Polyadenylation Element Binding Protein 2 Alternative Splicing Regulates Hif1Α During Chronic Hypoxia, Emily M. Mayo

USF Tampa Graduate Theses and Dissertations

Chronic pulmonary hypoxia commonly results in the sustained expression of HIF1 (hypoxia inducible factor 1), a heterodimeric transcription factor, that, if unrestrained, can result in dramatic vasculature remodeling, pulmonary arterial hypertension, and right-sided heart failure. Together, these pulmonary disorders cost approximately $100 billion annually to treat due to the limited therapeutic targets designed to inhibit HIF1 expression. In this study, we introduce a translational regulator of HIF1 expression, known as Cytosolic polyadenylation element binding proteins 2 (CPEB2). Our lab has previously demonstrated in cancer cells that alternatively spliced isoforms of CPEB2 regulate the translation of the HIF1 oxygen-dependent subunit, HIF1α, …

Circrev1 Expression In Triple-Negative Breast Cancer, Meagan P. Horton

USF Tampa Graduate Theses and Dissertations

Triple-negative breast cancer (TNBC) comprises only 24% of breast cancer cases, yet is the second leading cause of cancer mortality in women due to its aggressive nature (1). This increase in mortality is due to the lack of receptors for three targetable growth factors (HER2, progesterone, and estrogen receptors). Our previous studies have indicated that these cancers are highly dysregulated in respect to alternative splicing. Hence, we undertook a study aimed at identifying circular RNAs (circRNAs) generated from back-splicing events which were dysregulated in TNBC. We have identified a novel circRNA transcript, circular REV1 (circREV1), which is upregulated in our …

Bone Microenvironmental Control Of Skeletal Malignancy, Chen Hao Lo

USF Tampa Graduate Theses and Dissertations

Bone is a common site of metastasis for many solid malignancies. Bone-metastatic cancers pose a significant clinical problem worldwide and is among the main causes for cancer patient morbidity and mortality. Patients with advanced bone-metastatic diseases often present with either osteolytic or osteogenic bone diseases as their cancers progress. These bone pathologies are products of the cancer co-opting the local bone remodeling stroma to yield important growth nutrients and factors. Unfortunately, skeletal metastases remain incurable and are fatal. Identifying and understanding the causal multicellular and molecular interactions underlying skeletal malignancies can yield crucial ideas for targeting and inhibiting disease progression. …

New Mechanisms That Control Fact Histone Chaperone And Transcription-Mediated Genome Stability, Angelo Vincenzo De Vivo Diaz

USF Tampa Graduate Theses and Dissertations

The Role of deubiquitinating enzymes (DUBs) in transcription, replication and genome integrity is not one that has been extensively researched. OTU DUBs are a particular class of enzyme with very little known about them.OTUD5 is a cysteine protease in the OTU family responsible to processing lysine 48 and lysine 63 ubiquitin chains. Recently, it has been implicated in to play a role in transcription through its binding partner UBR5. OTUD5 has also been shown to interact with proteins such as PDCD5 and p53, potentially have great importance in cell fate. In this study, I describe new discovered functions for OTUD5 …

Regulation Of The Heat Shock Response And Hsf-1 Nuclear Stress Bodies In C. Elegans, Andrew Deonarine

USF Tampa Graduate Theses and Dissertations

The Heat Shock Response (HSR) is a highly conserved stress responsive molecular pathway that functions to promote appropriate protein folding in the cell. The HSR accomplishes this primarily through the use of molecular chaperones that serve to bind to misfolded or unfolded proteins to assist in stabilizing and folding proteins back to their native functional state. The master regulator of this pathway is a transcription factor known as Heat Shock Factor 1 (HSF1). HSF1 regulates molecular chaperone expression in the cell’s basal state, but can also be stress induced by diverse biotic and abiotic signals including thermal shock, oxidative stress, …

Role Of Ceramide-1 Phosphate In Regulation Of Sphingolipid And Eicosanoid Metabolism In Lung Epithelial Cells, Brittany A. Dudley

USF Tampa Graduate Theses and Dissertations

Ceramide 1-Phosphate (C1P) is a sphingolipid metabolite which plays a large role in inflammation, cell survival and proliferation¹. C1P is known to have both pro- and anti-apoptotic roles in lung cancer cells, governed by ceramide kinase (CERK), upstream of precursor ceramide (Cer)². Previous work reveals C1P serves as the liaison between sphingolipid and eicosanoid synthesis, by decreasing the dissociation rate of group IVA cytosolic PLA₂ (cPLA_2α) from the Golgi membrane, C1P directly activates this phospholipase for downstream eicosanoid synthesis and subsequent inflammatory response³. CERK has been discovered to modulate eicosanoid synthesis, …

The Impact Of Myeloid-Mediated Co-Stimulation And Immunosuppression On The Anti-Tumor Efficacy Of Adoptive T Cell Therapy, Pasquale Patrick Innamarato

USF Tampa Graduate Theses and Dissertations

Adoptive T cell therapy (ACT) in combination with lymphodepleting chemotherapy is an effective strategy to induce the eradication of tumors, providing long-term regression in cancer patients. However, only a minority of patients that receive ACT with tumor infiltrating lymphocytes (TILs) exhibit durable benefit. Thus, there is an urgent need to define strategies that potentiate anti-tumor activity conducted by adoptively transferred T cells. In these studies, we aimed to identify novel strategies to enhance the therapeutic efficacy of ACT. Accordingly, we describe the disparate roles of myeloid cells in the context of ACT characterized by the augmentation of TIL proliferation in …

Mechanistic And Translational Studies On Skeletal Malignancies, Jeremy Mcguire

USF Tampa Graduate Theses and Dissertations

New treatment strategies are desperately needed for treating skeletal malignancy. Skeletal malignancies can be either primary cancer that originated in the bone, such as osteosarcoma, or metastatic cancer that spread from another organ to the skeleton, as in the case of breast or prostate cancer. In this thesis, I will detail two projects that focus on the discovery of new treatment strategies for both primary skeletal malignancy and metastatic skeletal malignancy.

The first project focuses on the primary skeletal malignancy, osteosarcoma, a rare cancer that is commonly diagnosed in children and young adults and metastasizes to the lungs. The survival …