Cell Biology Commons^™

Mechanisms Of Sorting And Fission At The Endosomes, Kanika Dhawan

Theses & Dissertations

Endocytic trafficking is a fundamental cellular process that regulates the transport of lipids and proteins. Our lab focuses on the intracellular trafficking of receptors involved in cellular processes such as cell division, migration, and proliferation. Accordingly, the regulation of these trafficking pathways is tightly controlled, involving a complex series of events, of which a key step is the endosomal fission. Perturbations in the endosomal network can eventually lead to impaired receptor recycling to the plasma membrane (PM) and, therefore, have pathological consequences like Alzheimer’s disease and multiple cancers. Upon internalization, cargo-laden vesicles released from the PM fuse with the sorting …

Novel Molecular Mechanisms Of C-Terminal Eps15 Homology Domain (Ehd) Proteins In Endocytic Trafficking And Primary Ciliogenesis, Tyler M. Jones

Theses & Dissertations

Endocytic membrane trafficking is a key cellular process that is critical for regulating the transport of internalized cargoes such as lipids and receptors. Our lab focuses on understanding the mechanisms and cellular functions of the proteins that regulate this pathway. One family of proteins that has seen significant interest over recent years is the C-terminal Eps15 Homology Domain (EHD) family of proteins. Mammalians have four EHD paralogs (EHD1-4) that are expressed ubiquitously in tissues. These proteins have distinct yet overlapping functions in regulating endocytic pathways. EHD1 has been shown to induce constriction and is recruited to induce fission of tubular …

Multicopy Suppression Of Ribosomal Protein Deletion Mutants, Jacqualine Cerbone

Senior Honors Projects

To suppress the ribosome assembly defective phenotype of a ribosomal protein uS17- deficient mutant, various ribosomal proteins were used to act as multicopy suppressors. Ribosomal protein uS17 is a highly conserved component of the 30S (small) ribosomal subunit and is important for 30S subunit assembly. Mutants with a deletion of rpsQ (the gene encoding uS17) are viable but have a severe 30S subunit assembly defect and a temperature-sensitive (ts) phenotype. While fully assembled 30S subunits do form, incomplete ("20S") particles lacking several proteins accumulate. We hypothesized that increasing the intracellular concentration of one or more of the proteins missing from …

Cannabinoids And Retinal Fibrotic Disorders., Lucy June Sloan

Electronic Theses and Dissertations

Retinal fibrosis is detrimental to vision. Retinal pigment epithelial (RPE) cells contribute to several retinal fibrotic diseases. Upon exposure to TGF-β, a key fibrotic cytokine, RPE cells trans-differentiate to myofibroblasts marked by the integration of α-SMA fibers into F-actin stress fibers, which confer strong contractility. Myofibroblasts produce and contract the collagen-rich fibrotic scar and disrupt retinal architecture. In this study, we investigated the in vitro effects of the putative endocannabinoid compound N-oleoyl dopamine (OLDA) on TGF-β2 induced porcine RPE cell contraction and α-SMA expression. Using an in vitro collagen matrix contraction assay, we found that OLDA inhibited TGF-β2 induced contraction …

Novel Regulators Of Cellular Secretion Alter The Tumor Microenvironment To Drive Metastasis, Rakhee Bajaj

Dissertations and Theses (Open Access)

Lung cancer is a highly aggressive disease responsible for ~25% of all cancer-related deaths, due in part to its proclivity to metastasize. Treating metastasis holds potential for improving patient survival but requires a deeper investigation into the underlying mechanisms. Some of these processes that can regulate metastasis are: (1) Oncogenic targets of epithelial micro-RNAs (miRNAs) are epigenetically de-repressed upon loss of the miRNAs during epithelial-to-mesenchymal transition (EMT) and in cancer. EMT confers plasticity and fitness to cancer cells promoting their survival through the metastatic cascade. This cascade and EMT are initiated by loss of the miRNA200 family (miR-200) and the …

Characterization Of The Influence Of A Small Molecule Inhibitor On Ras-Related Proteins Interactions, Emilio Duverna

Graduate Theses and Dissertations

The Ras superfamily of small G proteins are involved in cell-signaling processes that, if not regulated, may lead to cell multiplication, apoptosis inhibition, and tumorigenesis. They function as molecular switches, which through GTP/GDP exchange cycle, switch on or off cellular activities. Overexpression and/or hyperactivity of these proteins have been linked to many diseases including various cancers. CDC42, a member of the Rho subfamily of the Ras superfamily of small G proteins, participates in the regulation of many cellular processes including cell adhesion, mitosis, and cytoskeletal rearrangements. CDC42 binds to and activates many effector proteins including CDC42-activated kinase (ACK). Abnormal activities …

Regulation Of C-C Chemokine Receptor 7 (Ccr7) Ligand-Mediated Internalization And Chemotaxis By G Protein-Coupled Receptor Kinase Family 4 (Grk-4, 5, 6) In Human Pediatric T-Cell Acute Lymphoblastic Leukemia (T-All), Eduardo Elias Chaib

Open Access Theses & Dissertations

Background and Significance: The Hispanic population is disproportionally affected by T-ALL (T-cell acute lymphoblastic leukemia) when compared to other races in the US. C-C Chemokine Receptor 7 (CCR7) in T-ALL is used during disease progression, and may lead to migration of cancerous cells into the Central Nervous System (CNS) of patients. Goals and Objectives: This project aims to find relevant rates and risk factors for T-ALL for the Hispanic population in the US/Mexico border region. The other aim is to assess the effect of the G protein-coupled Receptor Kinase 4 (GRK-4) family proteins on migration and receptor internalization through CCR7 …

Plant Homeodomain Finger Protein 20 (Phf20) And Its Homolog Phf20 Like 1 (Phf20l1) Define Two Distinct Non-Specific Lethal (Nsl) Complexes, Hieu Van, Hieu T. Van

Dissertations and Theses (Open Access)

Plant Homeodomain Finger Protein 20 (PHF20) and its homolog PHF20 Like 1 (PHF20L1) are known subunits of the Non-Specific Lethal (NSL) complex, which acetylates lysine residues on histone H4 and regulates gene expression. The current model assumes that PHF20 and PHF20L1 are present together in the NSL complex, although it has never been tested. Performing extensive biochemical analysis, we observed that PHF20 and PHF20L1 were exclusively and independently associated with the NSL complex. Our protein domain analysis showed that the C-termini of PHF20 and PHF20L1 are crucial for their interactions with the respective complexes. Furthermore, enrichment sites of PHF20 and …

Preparation Of Proteins And Peptides From Heat-Stabilized Defatted Rice Bran Via Solid State Fermentation And Investigating For Skin Health, Ali A. Bisly

Graduate Theses and Dissertations

Heat-stabilized defatted rice bran (HDRB) is an abundant and inexpensive agro-industrial by-product of rice milling and rice oil extraction process. Furthermore, HDRB is a potential source of proteins. However, the direct protein extraction has low yield of protein due to the impact of heat stabilization and oil extraction process which made the HDRB proteins bound and interact with other components. This research is based on using solid-state fermentation (SSF), which is a natural and cost-effective approach to facilitate protein extraction from HDRB using Bacillus subtilis (natto) Takahashi as a microorganism.

Response surface methodology (RSM) analysis was used with Box-Behnken design …

Differential Expression Of Cellular And Exosomal Microrna Isolated From Oral Cancer Cells And Their Resistance To Chemotherapy, Brady Petersen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: MicroRNAs are abundant small non-coding RNA with a variety of known functions, including transcriptional activation and inhibition. Recent evidence has suggested that microRNA expression may influence the responsiveness of some cancers to chemotherapy, including liver and lung cancers. Some evidence has now suggested that specific microRNAs, such as miR-21, miR-155, and miR-375, may influence oral cancer responsiveness to chemotherapy – although much remains to be discovered.

Objective: Based upon the lack of evidence in this area, the primary objective of this study was to evaluate microRNA expression and responsiveness among oral cancers.

Methods: Five commercially available oral cancer cell …

Feasibility Of Tubulin As A Control For Gene Expression Following Transfection In Mouse Monocyte/Macrophage-Like Cells, Ankita Chabra

Honors Program Theses and Research Projects

Transfection, which is the ability to modify host cells’ genetic content, has broad application in studying normal cellular processes, molecular mechanism of disease and gene therapy. There are several transfection techniques, and all require either a control or a reference gene. Commonly used controls for transfection experiments are housekeeping genes, which maintain expression for a given cell/tissue, experimental conditions, and treatment. However, recent research has uncovered that expression levels of housekeeping genes may vary depending on the gene, cell type and experimental conditions. A growing body of evidence demonstrates that housekeeping genes are inadequate internal standards for measuring gene expression …

Generating A Colorimetric Ssa4 Transcript Export Reporter For Multicopy Suppression Screen In S. Cerevisiae, Zaid Hatem

[Archive] Belmont University Research Symposium (BURS)

The export of mRNA from the nucleus to the cytoplasm is a regulatory point that is essential to the pathway of gene expression in eukaryotic cells. The export of mRNA transcripts is mediated through selective doorways called the nuclear pore complexes (NPC). Additionally, there are proteins associated with the nuclear pore complex that assist in facilitating the export. This includes association with the export receptor, Mex67, which binds to the transcript and ferries it through NPCs. During cellular stress, such as heat shock, the export of housekeeping mRNA transcripts is halted, forcing these transcripts to remain inside the nucleus and …

Identification And Characterization Of An Ftsq-Null Suppressor Gene In Streptomyces, Alexandra Sherman

Undergraduate Distinction Papers

Streptomyces coelicolor is a filamentous Gram-positive soil bacterium that grows similarly to fungi. The bacteria grow together in a mycelium-like structure that produces aerial hyphae above the media surface for sporulation. Evenly spaced crosswalls develop during cell division of the aerial filaments with the aid of division genes, including ftsZ and ftsQ. These cell division genes are essential for growth in the common bacterium and if silenced will cause the bacterium to die. Streptomyces uniquely retains the ability for growth after a deletion of either the ftsZ or ftsQ gene which causes a loss of septum formation in the …

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 …

Delineating The Exocytic Fusion Machinery Required For Mast Cell Exocytosis, Pratikshya Adhikari

Dissertations

Mast cells undergo exocytosis to release a wide array of inflammatory mediators by utilizing membrane fusion proteins-SNAREs (soluble-N-ethyl-maleimide sensitive factor attachment protein receptor) along with essential regulatory Munc18 and Munc13 proteins. Accumulating evidence in mast cell biology suggests the existence of distinct pools of mast cell mediators. However, the precise mechanism underlying the release of each mast cell mediator is not clear. To determine whether different exocytic machineries are required for differential mediator release, I used reconstitution to investigate the differential role of Munc18s in fusion machinery regulation. Munc18a and Munc18c stimulated VAMP2 and VAMP3-mediated lipid mixing, whereas Munc18b only …

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 …

Salicylic Acid And N-Hydroxypipecolic Acid At The Fulcrum Of The Plant Immunity-Growth Equilibrium, Alyssa Shields, Vanessa Shivnauth, Christian Danve M. Castroverde

Biology Faculty Publications

Salicylic acid (SA) and N-hydroxypipecolic acid (NHP) are two central plant immune signals involved in both resistance at local sites of pathogen infection (basal resistance) and at distal uninfected sites after primary infection (systemic acquired resistance). Major discoveries and advances have led to deeper understanding of their biosynthesis and signaling during plant defense responses. In addition to their well-defined roles in immunity, recent research is emerging on their direct mechanistic impacts on plant growth and development. In this review, we will first provide an overview of how SA and NHP regulate local and systemic immune responses in plants. We …

Effect Of Rehmannia Glutinosa Libosch Extract On Proliferation And Cardiogenic Pre-Differentiation Of Human Mesenchymal Stem Cells, Huu Dat Nguyen, Len Ho Thi, Xuan Bach Ho, Van Anh Cao, Duy Minh Le Hoang

BioMedicine

Background: Vietnamese medicine tried and tested certain bioactive compounds from plants to increase the rate of tissue immunomodulation, regeneration, and differentiation. Although there are many research papers discovered about phytochemicals of Rehmannia glutinosa Libosch and differentiation induction potential of some substances purified from this herbal, it finds difficult to seek research that investigated the effect of Rehmannia glutinosa Libosch extract on proliferation and cardiogenic differentiation of mesenchymal stem cells, even though it has commonly been used for a long time because of its function as a restorative and as a critical role in cardiovascular treatment in traditional.

Results: Our …

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 …

Development Of The Seqcode: A Proposed Nomenclatural Code For Uncultivated Prokaryotes With Dna Sequences As Type, William B. Whitman, Maria Chuvochina, Brian P. Hedlund, Philip Hugenholtz, Konstantinos T. Konstantinidis, Alison E. Murray, Marike Palmer, Donovan H. Parks, Alexander J. Probst, Anna-Louise Reysenbach, Luis M. Rodriguez-R, Ramon Rossello-Mora, Iain Sutcliffe, Stephanus N. Venter

Life Sciences Faculty Research

Over the last fifteen years, genomics has become fully integrated into prokaryotic systematics. The genomes of most type strains have been sequenced, genome sequence similarity is widely used for delineation of species, and phylogenomic methods are commonly used for classification of higher taxonomic ranks. Additionally, environmental genomics has revealed a vast diversity of as-yetuncultivated taxa. In response to these developments, a new code of nomenclature, the Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode), has been developed over the last two years to allow naming of Archaea and Bacteria using DNA sequences as the nomenclatural types. The SeqCode …

Conformational Flexibility And Local Frustration In The Functional States Of The Sars-Cov-2 Spike B.1.1.7 And B.1.351 Variants: Mutation-Induced Allosteric Modulation Mechanism Of Functional Dynamics And Protein Stability, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Structural and functional studies of the SARS-CoV-2 spike proteins have recently determined distinct functional states of the B.1.1.7 and B.1.351 spike variants, providing a molecular framework for understanding the mechanisms that link the effect of mutations with the enhanced virus infectivity and transmissibility. A detailed dynamic and energetic analysis of these variants was undertaken in the present work to quantify the effects of different mutations on functional conformational changes and stability of the SARS-CoV-2 spike protein. We employed the efficient and accurate coarse-grained (CG) simulations of multiple functional states of the D614G mutant, B.1.1.7 and B.1.351 spike variants to characterize …

Plasma Induced Reactive Oxygen Species-Dependent Cytotoxicity In Glioblastoma 3d Tumourspheres, Janith Wanigasekara, Carlos Barcia, Patrick J. Cullen, Brijesh Tiwari, James F. Curtin

Articles

The aim of this study was to determine the effects of a pin‐to‐plate cold atmospheric plasma (CAP) on U‐251 MG three‐dimensional (3D) glioblastoma spheroids under different conditions. 3D tumorspheres showed higher resistance to the CAP treatment compared to 2D monolayer cells. A single CAP treatment was able to induce cytotoxicity, while multiple CAP treatments augmented this effect. CAP was also able to induce cytotoxicity throughout the tumoursphere, and we identified that reactive oxygen species(ROS) plays a major role, while H2O2plays a partial role in CAP‐induced cytotoxicity in tumour-spheres. We conclude that ROS‐dependent cytotoxicity is induced uniformly throughout glioblastoma and epidermoid …

The Pathophysiological Mechanisms Of Alzheimer's Disease; Investigating Therapeutic Interventions For Disease Onset, Alexandra A. Sandberg

Electronic Theses and Dissertations

Alzheimer’s Disease is a multifarious disease that progressively affects more people as both the proportion of older adults in the population and life expectancy increase in both the United States and worldwide. This devastating disease is a result of rampant neuronal loss in the memory centers of the brain that robs the independence of those who are diagnosed and places a heavy burden on those who care for them. Traditionally speaking, research has focused on the hallmark pathology of amyloid plaques, targeting them to try and prevent disease onset. However, countless failures in clinical trials aimed at this said pathology …

Antioxidant Biomarkers And Nutraceutical Therapeutics In Neurodegeneration And Neurotrauma, Lilia A. Koza

Electronic Theses and Dissertations

Mild traumatic brain injury (mTBI), yielding a Glascow Coma Scale of 13-15, is the most commonly occurring severity of TBI. Pathology from mTBI consists of blood brain barrier disruption, neuroinflammation, oxidative stress, excitotoxicity, mitochondrial dysfunction, protein aggregation, axonal degeneration, and resulting neuronal death. These processes deplete the body’s endogenous antioxidant system. We report a retrospective analysis of antioxidant blood biomarkers in patients with a history of mTBI from a local sports medicine clinic, Resilience Code. We found persistent sex-specific antioxidant depletions in mTBI patients associated with worsened symptomology.

Certain populations, such as athletes, are at high risk for repetitive mTBI …

Organellar Zn2+ Homeostasis And The Role Of Trpml Channels In Neuronal Lysosome Physiology And Axonal Transport, Taylor Franklin Minckley

Electronic Theses and Dissertations

Zinc (Zn²⁺) is crucial for proper cellular function, and as such it is important to measure and track Zn²⁺ dynamics in living cells. Fluorescent sensors have been used to estimate Zn²⁺ content of subcellular compartments, but little is known about endolysosomal Zn2+ homeostasis. Similarly, although numerous sensors have been reported, it is unclear whether and how Zn²⁺ can be released from intracellular compartments into the cytosol due to a lack of probes that can detect physiological dynamics of cytosolic Zn²⁺. My dissertation started with comparing and characterizing different Zn²⁺ sensors including the …

Characterization Of Cofilin And Its Potential Role In The Epha4 Pathway, Brian Donald Condron

Master's Theses and Doctoral Dissertations

EphA4 is a receptor tyrosine kinase that is responsible for cellular adhesion and locomotion using repulsion signaling in early development of Xenopus laevis. EphA4 regulates cellular locomotion by controlling proteins within its signal transduction pathway, which may include the protein cofilin. Cofilin actively severs and removes actin monomers, thus altering the actin cytoskeleton, leading to the cessation of cellular crawl. During the gastrulation phase of embryonic development, individual cells are relocating to create the three primary germ layers of the organism. Failure of this process to occur results in attrition of the embryos, frequently by way of embryonic exogastrulation. …

Phosphatidylserine Externalization On Non-Apoptotic Cells And Lipid Scramblases In C. Elegans, Julia Frondoni

Electronic Theses and Dissertations

Cell corpse clearance is key for animals to avoid inflammation and autoimmune disease. To better understand the “eat me” signal of phosphatidylserine (PS) exposure for non-apoptotic corpse clearance, we attempted to disrupt the externalization of PS on C. elegans polar bodies. The second polar body undergoes a non-apoptotic form of cell death, loses membrane integrity, externalizes PS and is cleared by embryonic cells during early development. During apoptotic and necrotic cell death, PS asymmetry is disrupted by lipid scramblases, which translocate phospholipids between the leaflets of the lipid bilayer. We found neither apoptotic nor necrotic scramblases are required for PS …

Investigation Of Nuclear Envelope-Associated Progeria Proteins During Nuclear Envelope Rupture, Rhiannon Marie Sears

Dissertations and Theses

The nuclear envelope (NE) is a specialized extension of the endoplasmic reticulum critical for the proper protection and organization of the genome. This interphase-only structure is host to several proteins and their interacting constituents that have various and diverse cellular roles. Mutations in NE constituents are associated with several human diseases. A subset of these diseases, known as progeria syndromes, are characterized by the premature presentation of physiological aging in a variety of tissues. Mutations in the genes LMNA and BANF1, which encode the A-type lamins and barrier-to-autointegration factor (BAF), can lead to these multisystem progeroid diseases. Though the underlying …

Phip Variants Associated With Chung–Jansen Syndrome Disrupt Replication Fork Stability And Genome Integrity, Neysha Tirado-Class, Caitlin Hathaway, Wendy K. Chung, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

Chung–Jansen syndrome (CJS) is a rare, autosomal dominant disorder characterized by developmental delay, intellectual disability/cognitive impairment, behavioral challenges, obesity, and dysmorphic features. CJS is associated with heterozygous variants in PHIP (Pleckstrin-Homology Interacting Protein), a gene that encodes one of several substrate receptors for Cullin4-RING (CRL4) E3 ubiquitin ligase complex. Full-length PHIP, also called DCAF14, was recently identified to function as a replication stress response protein. Herein, we report the identification of two PHIP missense variants identified by exome sequencing in unrelated individuals with CJS. The variants p.D488V and p.E963G occur in different functional elements of DCAF14-WD40 repeat domain and pleckstrin …