Cell Biology Commons^™

Tick Extracellular Vesicles Enable Arthropod Feeding And Promote Distinct Outcomes Of Bacterial Infection, Adela S. Oliva Chávez, Xiaowei Wang, Liron Marnin, Nathan K. Archer, Holly L. Hammond, Erin E. Mcclure Carroll, Dana K. Shaw, Brenden G. Tully, Amanda D. Buskirk, Shelby L. Ford, L. Rainer Butler, Preeti Shahi, Kateryna Morozova, Cristina C. Clement, Lauren Lawres, Anya J. O'Neal, Choukri Ben Mamoun, Kathleen L. Mason, Brandi E. Hobbs, Glen A. Scoles, Eileen M. Barry, Daniel E. Sonenshine, Utpal Pal, Jesus G. Valenzuela, Marcelo B. Sztein, Marcela F. Pasetti, Michael L. Levin, Michail Kotsyfakis, Steven M. Jay, Jason F. Huntley, Lloyd S. Miller, Laura Santambrogio, Joao H.F. Pedra

Biological Sciences Faculty Publications

Extracellular vesicles are thought to facilitate pathogen transmission from arthropods to humans and other animals. Here, we reveal that pathogen spreading from arthropods to the mammalian host is multifaceted. Extracellular vesicles from Ixodes scapularis enable tick feeding and promote infection of the mildly virulent rickettsial agent Anaplasma phagocytophilum through the SNARE proteins Vamp33 and Synaptobrevin 2 and dendritic epidermal T cells. However, extracellular vesicles from the tick Dermacentor andersoni mitigate microbial spreading caused by the lethal pathogen Francisella tularensis. Collectively, we establish that tick extracellular vesicles foster distinct outcomes of bacterial infection and assist in vector feeding by acting …

Investigating The Antitumor Effects Of A Dsrna-Nanoparticle Complex In An In Vitro Ovarian Cancer Model, Aaron Lewis

Theses and Dissertations (Comprehensive)

An estimated 1 in 70 women will be diagnosed with ovarian cancer in their lifetime. Despite advanced detection and treatment methods, it remains a silent killer with an expected survival rate of 50%. A developing method in cancer treatment is the use of compounds that stimulate the immune system to aid in the body's fight against the disease. This project focused on the use of the potent immune stimulant double-stranded RNA (dsRNA), commercially available as polyinosinic:polycytidylic acid, poly(I:C), to induce cytotoxicity in two ovarian cancer cell lines; SKOV-3 and OVCAR-3. Some challenges exist with the delivery of dsRNA due to …

An Investigation Of The Role Of Basigin-Variant-1 In The Immune Response Within The Retina, Abigail D. Tompa

UNF Graduate Theses and Dissertations

The neural retina is considered an immune privileged area, in that the eye attempts to suppress the inflammatory response to preserve vision. If there is damage to the blood-retina barrier, such as in diabetes or macular degeneration, it is possible for monocytes to travel out of the blood vessels and into the retina. While studying retinoblastoma, a research group determined that the protein, Basigin, through its extracellular domain, elicits an immune response by enhancing transcription of the pro-inflammatory cytokine interleukin-6 (IL-6). Basigin is cell adhesion molecule that belongs to the immunoglobulin superfamily. The Basigin gene has two main transcripts, that …

Nuclear Aurora-A Kinase-Induced Hypoxia Signaling Drives Dissemination And Metastasis In Breast Cancer., Kristina Marinak Whately

Graduate Theses, Dissertations, and Problem Reports (ETD)

Metastatic breast cancer causes the vast majority of cancer-associated deaths, especially in triple negative breast cancers (TNBC). TNBC is still poorly understood and has no effective treatment. Here we reveal that presence of Aurora-A Kinase (AURKA) in the nucleus and metastatic dissemination are molecularly connected through HIF1 (Hypoxia induced factor-1) signaling. The nuclear AURKA in the complex with constitutively expressed HIF-1β subunit activates transcription of “hypoxia induced genes” under normoxic conditions (the phenomenon called pseudohypoxia) without upregulation of oxygen-sensitive HIF-1α subunit. We uncover that AURKA preferentially binds to and phosphorylates HIF-1β, and co-localizes with HIF complex on DNA. The mass …

Molecular Signatures Of Sexual Communication In The Phlebotomine Sand Flies, Paul V. Hickner, Nataliya Timoshevskaya, Ronald J. Nowling, Frédéric Labbé, Andrew D. Nguyen, Mary Ann Mcdowell, Carolina N. Spiegel, Zainulabeuddin Syed

Biology Faculty Publications

Phlebotomine sand flies employ an elaborate system of pheromone communication wherein males produce pheromones that attract other males to leks (thus acting as an aggregation pheromone) and females to the lekking males (sex pheromone). In addition, the type of pheromone produced varies among populations. Despite the numerous studies on sand fly chemical communication, little is known of their chemosensory genome. Chemoreceptors interact with chemicals in an organism’s environment to elicit essential behaviors such as the identification of suitable mates and food sources. Thus, they play important roles during adaptation and speciation. Major chemoreceptor gene families, odorant receptors (ORs), gustatory receptors …

Arp2/3-Independent Wave/Scar Pathway And Class Xi Myosin Control Sperm Nuclear Migration In Flowering Plants, Mohammad F. Ali, Umma Fatema, Xiongbo Peng, Samuel W. Hacker, Daisuke Maruyama, Meng-Xiang Sun, Tomokazu Kawashima

Plant and Soil Sciences Faculty Publications

After eukaryotic fertilization, gamete nuclei migrate to fuse parental genomes in order to initiate development of the next generation. In most animals, microtubules control female and male pronuclear migration in the zygote. Flowering plants, on the other hand, have evolved actin filament (F-actin)-based sperm nuclear migration systems for karyogamy. Flowering plants have also evolved a unique double-fertilization process: two female gametophytic cells, the egg and central cells, are each fertilized by a sperm cell. The molecular and cellular mechanisms of how flowering plants utilize and control F-actin for double-fertilization events are largely unknown. Using confocal microscopy live-cell imaging with a …

A Molecular Toolset For The In Vivo Detection Of A Sulfolobus Islandicus Leucyl Trna Synthetase Paralog, Nicholas Michael Bretz

Theses and Dissertations

An ancient and ubiquitous set of enzymes known as the aminoacyl-tRNA synthetases are required for the viability of all organisms. The aminoacyl-tRNA synthetases catalyze the attachment of amino acids onto tRNA molecules. The aminoacylated, or charged, tRNA is then transported and utilized at the ribosome for the synthesis of proteins. The genome of the hyperthermophilic microorganism Sulfolobus islandicus (S. islandicus) harbors a unique leucyl-tRNA synthetase paralog, LeuRS-I, of unknown function. While its duplicate, LeuRS-F, carries out all the classical functions of LeuRS-family enzymes, LeuRS-I fails to charge leucine onto tRNALeu, despite its ability to activate this amino acid and bind …

The Cellular Origin And Molecular Drivers Of Claudin-Low Mammary Cancer, Patrick D. Raedler

Theses & Dissertations

Breast cancers of the claudin-low subtype make up a substantial portion of triple-negative breast cancers and have stem cell-like and mesenchymal features. Although it has been recognized for some time that this breast cancer subtype is highly aggressive and difficult to treat, the molecular drivers and cellular origin of claudin-low breast cancer have been poorly defined. The lack of suitable in vivo models has prohibited the study of tumor initiation and progression of this subtype. In this work, we report two novel mouse models that, upon expression of oncogenic RAS in the mammary epithelium, develop highly metastatic triple-negative mammary tumors …

Mechanisms By Which Mnte-2-Pyp Suppresses Prostate Cancer Cell Growth, Yuxiang Zhu

Theses & Dissertations

Prostate cancer patients are often treated with radiotherapy. MnTE-2-PyP, is a superoxide dismutase (SOD) mimic and a known radioprotector of normal tissues. Our recent work demonstrates that MnTE-2-PyP also inhibits prostate cancer progression with radiotherapy; however, the mechanisms remain unclear. In this thesis, we identified that MnTE-2-PyP-induced intracellular H2O2 levels are critical in inhibiting growth of prostate cancer cells. We found that MnTE-2-PyP induced protein oxidations in PC3 cells and one major group of oxidized protein targets were involved in energy metabolism. The oxidative phosphorylation rates were significantly enhanced in both PC3 and LNCaP cells with MnTE-2-PyP treatment, but mitochondrial …

Single-Fluorophore Sensors For Mechanical Force In Living Cells, Sarah Kricheff

Honors Scholar Theses

Mechanotransduction is the process by which a mechanical stimulus is converted to a cellular signal. This process is heavily influential of cell morphology, differentiation, and behavior. However, altered levels of mechanical stimuli are also found in many pathological contexts. For example, cancerous cells have stiffer surrounding tissue than healthy cells, and research suggests that this alters cell behavior and promotes metastasis. Despite these findings, the cellular processes behind these signaling alterations remain widely unknown. Understanding these cascades is critical, as involved proteins can give us a deeper understanding of the role of mechanotransduction, and certain proteins can potentially be targeted …

K2p2.1 (Trek-1) Potassium Channel Activation Protects Against Hyperoxia-Induced Lung Injury, Tatiana Zyrianova, Benjamin Lopez, Riccardo Olcese, John Belperio, Christopher M. Waters, Leanne Wong, Victoria Nguyen, Sriharsha Talapaneni, Andreas Schwingshackl

Physiology Faculty Publications

No targeted therapies exist to counteract Hyperoxia (HO)-induced Acute Lung Injury (HALI). We previously found that HO downregulates alveolar K_2P2.1 (TREK-1) K⁺ channels, which results in worsening lung injury. This decrease in TREK-1 levels leaves a subset of channels amendable to pharmacological intervention. Therefore, we hypothesized that TREK-1 activation protects against HALI. We treated HO-exposed mice and primary alveolar epithelial cells (AECs) with the novel TREK-1 activators ML335 and BL1249, and quantified physiological, histological, and biochemical lung injury markers. We determined the effects of these drugs on epithelial TREK-1 currents, plasma membrane potential (Em), and intracellular Ca …

Structural Characterization And In Vitro Lipid Binding Studies Of Non-Specific Lipid Transfer Protein 1 (Nsltp1) From Fennel (Foeniculum Vulgare) Seeds, Mekdes Megeressa, Bushra Siraj, Shamshad Zarina, Aftab Ahmed

Pharmacy Faculty Articles and Research

Non-specific lipid transfer proteins (nsLTPs) are cationic proteins involved in intracellular lipid shuttling in growth and reproduction, as well as in defense against pathogenic microbes. Even though the primary and spatial structures of some nsLTPs from different plants indicate their similar features, they exhibit distinct lipid-binding specificities signifying their various biological roles that dictate further structural study. The present study determined the complete amino acid sequence, in silico 3D structure modeling, and the antiproliferative activity of nsLTP1 from fennel (Foeniculum vulgare) seeds. Fennel is a member of the family Umbelliferae (Apiaceae) native to southern Europe and the Mediterranean …

Unconventional Constituents And Shared Molecular Architecture Of The Melanized Cell Wall Of C. Neoformans And Spore Wall Of S. Cerevisiae, Christine Chrissian, Coney Pei-Chin Lin, Emma Camacho, Arturo Casadevall, Aaron M. Neiman, Ruth E. Stark

Publications and Research

The fungal cell wall serves as the interface between the cell and the environment. Fungal cell walls are composed largely of polysaccharides, primarily glucans and chitin, though in many fungi stress-resistant cell types elaborate additional cell wall structures. Here, we use solid-state nuclear magnetic resonance spectroscopy to compare the architecture of cell wall fractions isolated from Saccharomyces cerevisiae spores and Cryptococcus neoformans melanized cells. The specialized cell walls of these two divergent fungi are highly similar in composition. Both use chitosan, the deacetylated derivative of chitin, as a scaffold on which a polyaromatic polymer, dityrosine and melanin, respectively, is assembled. …

A Two-Clone Approach To Study Signaling Interactions Among Neuronal Cells In A Pre-Clinical Alzheimer’S Disease Model, Catherine J. Yeates, Ankita Sarkar, Prajakta Deshpande, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

To understand the progression of Alzheimer's disease, studies often rely on ectopic expression of amyloid-beta 42 (Aβ42) throughout an entire tissue. Uniform ectopic expression of Aβ42 may obscure cell-cell interactions that contribute to the progression of the disease. We developed a two-clone system to study the signaling cross talk between GFP-labeled clones of Aβ42-expressing neurons and wild-type neurons simultaneously generated from the same progenitor cell by a single recombination event. Surprisingly, wild-type clones are reduced in size as compared with Aβ42-producing clones. We found that wild-type cells are eliminated by the induction of cell death. Furthermore, aberrant activation of c-Jun-N-terminal …

Does The Presence Of Multiple Β-Lactamases In Gram-Negative Bacilli Impact The Results Of Antimicrobial Susceptibility Tests And Extended-Spectrum Β-Lactamase And Carbapenemase Confirmation Methods?, Fred C. Tenover, Caitlin M. Dela Cruz, Scott Dewell, Victoria M. Le, Isabella A. Tickler

Biology Faculty Publications

Objectives: Many multidrug-resistant Gram-negative bacilli (MDR-GNB) harbour multiple β-lactamases. The aim of this study was to assess the impact of multiple β-lactamase carriage on the accuracy of susceptibility tests and extended-spectrum β-lactamase (ESBL) and carbapenemase confirmation methods.

Methods: A total of 50 MDR-GNB, of which 29 carried multiple β-lactamases, underwent broth microdilution (BMD) and disk diffusion (DD) testing as well as confirmation tests for ESBLs and carbapenemases. Whole-genome sequencing (WGS) was used for β-lactamase gene identification.

Results: Categorical agreement of BMD and DD testing results ranged from 86.5 to 97.7% for 10 β-lactam agents. BMD and DD algorithms for ESBL …

Role Of Β-Glucan Structure In Dectin-1 Homo- And Hetero-Oligomerization In Innate Anti-Fungal Immunity, Eduardo U. Anaya

Biomedical Sciences ETDs

Dectin-1A is a C-type Lectin innate immunoreceptor that recognizes β-(1,3)-glucan, a structural component of Candida species cell walls. Dectin-1 has eight alternative splice isoforms including, A and B. Innate immunocytes can express one or both isoforms, but neither their relative responsiveness to β-glucan nor the potential for inter-isoform signaling cross-talk is well understood. In this study, we determine how the different structures of soluble β-glucans affect both isoforms and unravel how differences in glucan structure impact the earliest events in Dectin-1 signaling. Using quantitative microscopy techniques, we explored the role of glucan structure on Dectin-1A oligomerization, which is thought to …

Disruption Of Dna Polymerase Zeta Promotes An Innate Immune Response, Sara Martin

Dissertations and Theses (Open Access)

DNA polymerase ζ (pol ζ) is a specialized polymerase that protects cells from the consequences of DNA damage and stress. Without pol ζ function mammalian cells and yeast are exquisitely sensitive to genotoxic stresses including ultraviolet irradiation and platinum compounds such as the chemotherapeutic agent cisplatin. This elevated sensitivity arises from the central role of pol ζ in lesion bypass. Pol ζ is also required to protect cells from endogenous genomic damage or stress. In primary mammalian cells, the function of pol ζ is required for genome protection and normal proliferation. Immortalized Rev3lknockout (KO) MEFs are under considerable constitutive …

Calcium Dyshomeostasis In Neurodegeneration, Nicholas Emanuel Karagas

Dissertations and Theses (Open Access)

Neurodegenerative diseases, despite constituting a major and growing cause of mortality globally, have few effective treatments. In order to develop novel therapeutics to combat neurodegeneration, a better understanding of the molecular mechanisms underlying these diseases is needed. Neurons rely on Ca²⁺ to mediate many of their unique functions, and aberrant Ca²⁺ signaling has been broadly implicated in neurodegeneration. The goal of this dissertation is to delineate specific examples of Ca²⁺ dyshomeostasis that I have uncovered in Drosophila models of neurodegeneration.

I first define the role a neurodegeneration-associated mutation plays in perturbing presynaptic [Ca²⁺], which is …

The Role Of Liver Sinusoidal Endothelial Cells In Liver Malady Homeostasis, Fatima Cabral

Department of Biochemistry: Dissertations, Theses, and Student Research

Current literature described techniques for the purification of liver cell types through text alone. The techniques described for the isolation of liver sinusoidal endothelial cells as well as hepatocytes described here are modified from a published article in the Journal of Visualized experiments. The video protocol allows for the user to successfully isolate cells as the most difficult parts of the procedure are demonstrated visually. The detection of liver maladies such as the non-alcoholic fatty liver disease, the stage if this disease and differentiation between non-alcoholic and alcoholic fatty liver disease is demonstrated in the development of a unique panel …

Gap Junctions In Stem Cells Provide An Essential Conduit For Cell-Cell Communication, Jacob M. Gunn, David L. Geenen

Student Summer Scholars Manuscripts

Introduction: Myocardial infarction (MI) results from the death of cardiomyocytes (CM) following obstruction of blood flow and diminished oxygen supply to the tissue (hypoxia). Human adipose tissue-derived stem cells (hADSCs) used in pre-clinical models can replace damaged CM, however, this has not been replicated in human clinical trials due to early loss of hADSCs. We hypothesize that coupling of hADSCs to dying CMs may account for part of this loss. Furthermore, cell culturing is essential aspect of any in-vitro experiment. Through multiple trials we sought to maximize the efficiency of our culturing procedures in order to best facilitate the …

Impact Of Global Structure On Diffusive Exploration Of Organelle Networks, Aidan I. Brown, Laura M. Westrate, Elena F. Koslover

University Faculty Publications and Creative Works

We investigate diffusive search on planar networks, motivated by tubular organelle networks in cell biology that contain molecules searching for reaction partners and binding sites. Exact calculation of the diffusive mean first-passage time on a spatial network is used to characterize the typical search time as a function of network connectivity. We find that global structural properties — the total edge length and number of loops — are sufficient to largely determine network exploration times for a variety of both synthetic planar networks and organelle morphologies extracted from living cells. For synthetic networks on a lattice, we predict the search …

A Functional Three-Dimensional Microphysiological Model Of Myeloma Bone Disease, Richard Visconti

Seton Hall University Dissertations and Theses (ETDs)

Multiple myeloma (MM) is a hematologic cancer caused by a mature B cell neoplasm, or plasmacytoma, that infiltrates the skeleton at several sites. The disease is characterized by uninhibited transformed plasma cell proliferation that disrupts skeletal homeostasis leading to decreased bone modeling and increased bone resorption. Osteolytic lesions (OL) or voids left in the bone, remain long after the treatment of the cancer and indicate disease progression to myeloma bone disease (MBD). Current combinatorial MM therapies inhibit malignant plasma cell proliferation, slow the progression towards MBD, and increase the mean five-year survival rate, but do little to improve osteoblastic function …

P53 Drives A Transcriptional Program That Elicits A Non-Cell-Autonomous Response And Alters Cell State In Vivo, Sydney Moyer

Dissertations and Theses (Open Access)

Cell stress and DNA damage activate the tumor suppressor p53, triggering transcriptional activation of a myriad of target genes. The molecular, morphological, and physiological consequences of this activation remain poorly understood in vivo. We activated a p53 transcriptional program in mice by deletion of Mdm2, a gene which encodes the major p53 inhibitor. By overlaying tissue-specific RNA-sequencing data from pancreas, small intestine, ovary, kidney, and heart with existing p53 ChIP-sequencing, we identified a large repertoire of tissue-specific p53 genes and a common p53 transcriptional signature of seven genes which included Mdm2 but not p21. Global p53 activation …

Sine Oculis Homeobox Homolog 1 (Six1) Plays A Critical Role In The Progression Of Pulmonary Fibrosis., Cory Wilson

Dissertations and Theses (Open Access)

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonia with a median survival time of 2-4 years after diagnosis. The alarming mortality rate is due to the lack of effective treatments. IPF is a chronic disease that is characterized by alveolar destruction due to increasing extracellular matrix deposition that leads to poor lung compliance, impaired gas exchange, and ultimately respiratory failure. Repetitive alveolar epithelial injury is a central process to the underlying pathology with injury to the type II alveolar epithelial cells (AT2) specifically being a key player in the pathogenesis of IPF. Recent studies have shown that …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations and Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations and Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

Packaging And Secretion Of Airway Mucins, Oanh Ngoc Hoang

Dissertations and Theses (Open Access)

In the conducting airways of the lungs, the mobile mucus gel layer sits on top of the airway epithelium, and through ciliary beating it is propelled up the trachea into the pharynx where it is swallowed and cleared. This gel layer is composed of secreted mucins that become hydrated once reaching the airway lumen. Mucins are secreted at a baseline rate and at a stimulated rate, dependent on the amount of agonist. Baseline secretion is responsible for steady clearance of inhaled particles and pathogens. Stimulated secretion is thought to play a role in trapping helminths though mucus occlusion in small …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations and Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …

Ionic Mechanism Of Lysosomal Function And Cell Metabolism, Jian Xiong

Dissertations and Theses (Open Access)

Two Pore Channels (TPCs) are endolysosomal ion channels that are permeable to sodium and calcium. Defects in TPCs have been implicated to impair vesicle trafficking, autophagy and cell metabolism control; however, the detailed mechanism remains largely unknown. In this study, I show that TPCs are critical for appropriate cargo delivery to the lysosomes and deletion of either TPC1 or TPC2 leads to delayed clearance of autophagosomes, resulting in enlarged lysosomes and accumulated contents inside the lysosomes. Cells with both TPC deleted also exhibit 50% reduction in lysosomal amino acids under normal culture conditions, leading to reduced homeostatic mTORC1 activation.

Glutamine …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations and Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …