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 …

Self And Microbiota-Derived Epitopes Induce Cd4⁺ T Cell Anergy And Conversion Into Cd4⁺Foxp3⁺ Regulatory Cells, Michal P. Kuczma, Edyta A. Szurek, Anna Cebula, Vu L. Ngo, Maciej Pietrzak, Piotr Kraj, Timothy L. Denning, Leszek Ignatowicz

Biological Sciences Faculty Publications

The physiological role of T cell anergy induction as a key mechanism supporting self-tolerance remains undefined, and natural antigens that induce anergy are largely unknown. In this report, we used TCR sequencing to show that the recruitment of CD4⁺CD44⁺Foxp3⁻CD73⁺FR4⁺ anergic (Tan) cells expands the CD4⁺Foxp3⁺ (Tregs) repertoire. Next, we report that blockade in peripherally-induced Tregs (pTregs) formation due to mutation in CNS1 region of Foxp3 or chronic exposure to a selecting self-peptide result in an accumulation of Tan cells. Finally, we show that microbial antigens from Akkermansia muciniphila …

Impact Of Targeting Glycosylated Ceramides On Tumorigenic Properties, And Characterization Of Sphingolipids In Head And Neck Tumors, Katherine E. Hylton

Theses and Dissertations

Sphingolipids play a crucial role in signaling, membrane structure, and migration, making them important molecules in cancer development, metastasis, and drug resistance. While some sphingolipids have been associated with pro-apoptotic or pro-survival behaviors, the role of many sphingolipids in cancer remains poorly defined. Chapter 1 of this study investigated the impact of three enzymes that compose most of the ceramide to Lc3 ceramide pathway – UGCG, GBA, and B3GNT5 – and how their alteration impacts chemoresistance and basal membrane invasion in vitro. It was found that the CΒE-induced inhibition of GBA, which converts glucosylceramide to ceramide, has no effects on …

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 …

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 …

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 …

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 …

Evaluation Of The Xpert Carba-R Nxg Assay For Detection Of Carbapenemase Genes In A Global Challenge Set Of Pseudomonas Aeruginosa Isolates, Fred C. Tenover, Christian M. Gill, Tomefa E. Asempa, Isabella A. Tickler, Caitlin M. Dela Cruz, David P. Nicolau

Biology Faculty Publications

The growing prevalence and diversity of carbapenemase producers among carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates warrants an expansion of detection capabilities. The purpose of this study was to evaluate the performance of the commercially available Xpert Carba-R (Carba-R) and the research-use-only Xpert Carba-R NxG (Carba-R NxG) in a global collection of P. aeruginosa. The challenge set included 123 P. aeruginosa clinical isolates from 12 countries. Isolates were previously categorized via PCR or whole-genome sequencing. Carbapenemase classes tested include VIM, IMP, NDM, SPM, KPC, and GES. Non-carbapenemase (non-CP)-harboring isolates were also tested (negative control). Isolates were tested using the Carba-R NxG and …

Fine-Tuning Of Alanyl-Trna Synthetase Quality Control Alleviates Global Dysregulation Of The Proteome, Paul Kelly, Arundhati Kavoor, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

One integral step in the transition from a nucleic acid encoded-genome to functional proteins is the aminoacylation of tRNA molecules. To perform this activity, aminoacyl-tRNA synthetases (aaRSs) activate free amino acids in the cell forming an aminoacyl-adenylate before transferring the amino acid on to its cognate tRNA. These newly formed aminoacyl-tRNA (aa-tRNA) can then be used by the ribosome during mRNA decoding. In Escherichia coli, there are twenty aaRSs encoded in the genome, each of which corresponds to one of the twenty proteinogenic amino acids used in translation. Given the shared chemicophysical properties of many amino acids, aaRSs have …

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, …

Herb-Layer Dynamics In An Old-Growth Forest: Vegetation–Environment Relationships And Response To Invasion-Related Perturbations, Taylor M. Buskey, Margaret E. Maloney, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Temperate forests of eastern North America are subject to multiple invasions from non-native species that have the potential to drive long-term dynamics in biodiversity. Garlic mustard (Alliaria petiolata (M. Bieb.) Cavara and Grande) is an invasive plant in many deciduous forests, and management efforts often focus on removing this species to initiate native species restoration. Agrilus planipennis Fairmaire (emerald ash borer; Coleoptera: Buprestidae) is a non-native insect pest that has caused substantial loss of ash trees (Fraxinus spp. L.) in North America. Our goal was to understand how the herbaceous layer in an old-growth forest responded to the removal of …

Mechanistic Insights Into Strigolactone Biosynthesis, Signaling And Regulation During Plant Growth And Development, Kaiser Iqbal Wani, Andleeb Zehra, Sadaf Choudhary, M Naeem, M. Masroor A. Khan, Christian Danve Castroverde, Tariq Aftab

Biology Faculty Publications

Strigolactones (SLs) constitute a group of carotenoid-derived phytohormones with butenolide moieties. These hormones are involved in various functions, including regulation of secondary growth, shoot branching and hypocotyl elongation, and stimulation of seed germination. SLs also control hyphal branching of arbuscular mycorrhizal (AM) fungi, and mediate responses to both abiotic and biotic cues. Most of these functions stem from the interplay of SLs with other hormones, enabling plants to appropriately respond to changing environmental conditions. This dynamic interplay provides opportunities for phytohormones to modulate and augment one another. In this article, we review our current mechanistic understanding of SL biosynthesis, receptors …

Minimal Structural Elements Required For Midline Repulsive Signaling And Regulation Of Drosophila Robo1, Haley E. Brown, Timonthy A. Evans

Biological Sciences Faculty Publications and Presentations

The Roundabout (Robo) family of axon guidance receptors has a conserved ectodomain arrangement of five immunoglobulin-like (Ig) domains plus three fibronectin type III (Fn) repeats. Based on the strong evolutionary conservation of this domain structure among Robo receptors, as well as in vitro structural and domain-domain interaction studies of Robo family members, this ectodomain arrangement is predicted to be important for Robo receptor signaling in response to Slit ligands. Here, we define the minimal ectodomain structure required for Slit binding and midline repulsive signaling in vivo by Drosophila Robo1. We find that the majority of the Robo1 ectodomain is dispensable …

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 …

Identifying New Markers And Mechanisms Of Mitochondrial Defect During Aging, Catherine Chang

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Mitochondrial dysfunction is a hallmark of aging and has been closely tied to age-related pathologies, such as cancer, cardiovascular diseases, neurodegenerative disorders, and metabolic syndromes. Though the consequences of mitochondrial defects are well documented, little is known about the molecular events that occur with age that transform healthy mitochondria into dysfunctional ones. Past studies have attempted to uncover the underlying proteomic changes in age, however, most of these results do not take into account population heterogeneity often associated with aging, thus highlighting the need for single-cell analysis. Technological barriers have impeded in-depth proteomic studies of aging mitochondria on a single …

The Influence Of Riparian Invasion By The Terrestrial Shrub Lonicera Maackii On Aquatic Macroinvertebrates In Temperate Forest Headwater Streams, Michelle N. Little, Kevin W. Custer, Eric B. Borth, Julia I. Chapman, Mitchell J. Kukla, Corey Kuminecz, Margaret E. Maloney, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

The ecology of headwater streams is tightly linked to the riparian zone through organic matter subsidies which are highly susceptible to alteration due to biological invasion. Lonicera maackii is a non-native shrub that is a highly successful invader of headwater stream riparian zones in the American Midwest. We assessed effects on benthic macroinvertebrates across a gradient of invasion intensity from references sites with minimal invasion to a site that had a very heavy invasion. Benthic macroinvertebrates were sampled throughout the year and compositional differences were assessed using Non-metric Multidimensional Scaling ordination, and by comparing the prevalence of sensitive (Ephemeroptera, Plectoptera, …

Inactivation Of Hippo And Cjun-N-Terminal Kinase (Jnk) Signaling Mitigate Fus Mediated Neurodegeneration In-Vivo, Ankita Sarkar, Abijeet Singh Mehta, Prajakta Deshpande, Madhuri Kango-Singh, Udai Bhan Pandey, Amit Singh

Biology Faculty Publications

Amyotrophic Lateral Sclerosis (ALS), a late-onset neurodegenerative disorder characterized by the loss of motor neurons in the central nervous system, has no known cure to-date. Disease causing mutations in human Fused in Sarcoma (FUS) leads to aggressive and juvenile onset of ALS. FUS is a well-conserved protein across different species, which plays a crucial role in regulating different aspects of RNA metabolism. Targeted misexpression of FUS in Drosophila model recapitulates several interesting phenotypes relevant to ALS including cytoplasmic mislocalization, defects at the neuromuscular junction and motor dysfunction. We screened for the genetic modifiers of human FUS-mediated neurodegenerative phenotype using molecularly …

Molecular And Ultrastructure Study Of Tight Junction During Experimental Entamoeba Spp. Infection, Athraa A. Al-Hilfi Dr, Maha Khalil Al-Malak, Shereen Jawad Al-Ali, Muslim Abd-Ulrahman Al-Tomah

Karbala International Journal of Modern Science

Entamoeba spp. in particular E.histolytica is the main reason of human amoebiasis. The molecular mechanism of its pathogenicity is poorly understood, therefore the aim this study is to investigate these mechanism on both molecular and ultrastructure levels. Tight junction (TJ) genes Claudin-1 (Cldn1) and Occludin (Ocln) were investigated by real time PCR and the pathological changes by scanning electron microscopy (SEM) and transmission electron microscope (TEM), the result showed that the gene expression levels of TJ genes were significantly high in rats infected with E. histolytica E. dispar and E. moshkovskii after 28, 14, 7 days in compare with healthy …

Insights Into Desiccation Tolerance: Properties Of Late Embryogenesis Abundant Proteins From Embryos Of Artemia Franciscana, Blase Matthew Leblanc

LSU Doctoral Dissertations

LEA proteins are a family of intrinsically disordered proteins that are expressed in various life stages of anhydrobiotic organisms and have been strongly associated with survival during water stress. The brine shrimp Artemia franciscana is the only known anhydrobiotic animal that expresses LEA proteins from Groups 1, 3, and 6. Here, I report that AfrLEA6, a novel Group 6 LEA protein, is most highly expressed in embryos during diapause and decreases throughout pre-emergence development. Notably, there is an acute drop in expression upon termination of the diapause state and the titer of AfrLEA6 during diapause is 10-fold lower than values …

Epithelial-Mesenchymal Status Predics Tumor Agressivenss, Chemoresistance And Invasiveness In High Grade Serous Ovarian Cancer, Linda Sanderman

Electronic Theses, Projects, and Dissertations

High Grade Serous Ovarian Cancer (HGSOC) is one of the deadliest gynecological diseases in the United States ranking fifth in cancer deaths among women. Approximately 22 thousand new cases are expected to occur in the year 2020, and unfortunately, it is estimated that 14 thousand women will succumb to the disease; the incidence to death ratio, 64%, remains high despite current research. Current treatment includes debulking surgery followed by combinatorial chemotherapeutics with platinum-based and taxol-based compounds. But despite aggressive surgery and standard-of-care chemotherapeutics, 80% of patients will experience a recurrence and only 15-30% of those with recurring disease will respond …

Protein Phosphatase 2a Suppresses Spindle Elongation In Saccharomyces Cerevisiae, Shoily P. Khondker

Dissertations, Theses, and Capstone Projects

Eukaryotic cell division is an essential process that is carried out by the cell cycle, a tightly controlled process that has been extensively studied in the budding yeast Saccharomyces cerevisiae. The cell cycle is driven by Cyclin Dependent Kinase (Cdk1) activity. Protein phosphatase 2A-Cdc55 (PP2A^Cdc55) reverses Cdk1 phosphorylation events during late stages of the cell cycle to ensure the correct order of events. This thesis presents evidence that the anaphase inhibitor Pds1 is a PP2A^Cdc55 target. Pds1 binds to and inhibits separase (Esp1). Esp1 triggers sister chromatid segregation by cleaving the cohesin complex that holds the …

Science, But Not Fiction: Colby Researchers Consider How "Extreme-Ophiles" Survive And Thrive In The World's Toughest Places, Gerry Boyle

Colby Magazine

"We're exploring how the cell makes the decision to do this," said Assistant Professor of Biology Ron Peck.

Patenting Antibodies: A Complication In Written Description Jurisprudence, Krisha Yadav-Rajan

DePaul Journal of Health Care Law

No abstract provided.

Investigating The Redox Sensitivity Of Mitf Splice Variants, Rachel Berryman

Senior Theses

Within pigment-producing cells known as melanocytes, the transcription factor MITF is intimately involved in regulating genes associated with cell cycle maintenance and melanocyte differentiation. Research, however, has provided conflicting results on the relationship between the expression levels of MITF and melanocyte cell fate. To complicate matters, two splice variants of MITF exist, differing by only 18 base pairs. These variants have been observed at variable levels of expression in melanocyte and melanoma cells, raising the question as to their functional purpose. Building upon previous research by the Leachman/Cassidy lab that identified the redox sensitivity of MITF while additionally establishing a …

Microglia-Neuron Interactions In A Mouse Model Of Low Grade Neuroepithelial Tumors, Veolette Hanna

Honors Scholar Theses

Microglia are the macrophages of the brain and spinal cord, playing an important role in the immune response to disease states of the nervous system. This study conducts an investigation on the activity of microglia in response to low grade neuroepithelial tumors. Using mouse models and microglial markers, a qualitative and quantitative analysis of microglia activation, migration, and invasion within the brain cortex during early stages of tumor development was conducted. It was found that the presence of a low grade neuroepithelial tumor in the cortex of one hemisphere of the brain causes significant microglia activation in comparison to the …

Assessing The Influence Of Riparian Invasion By The Shrub Lonicera Maackii On Terrestrial Subsidies To Headwater Streams, Erin C. Rowekamp, Julia I. Chapman, Ryan Mcewan

Biology Faculty Publications

Invasion of Amur honeysuckle (Lonicera maackii) into riparian areas of headwater streams creates strong potential for alterations of terrestrial subsidies that may drive bottom-up effects on aquatic biota. In this study, we analyzed effects of L. maackii on terrestrial subsidies in stream sites that represented a gradient of invasion intensity in temperate deciduous forests of southwestern Ohio (USA). Leaf litter biomass, terrestrial and aquatic fine woody debris (0.5–9.9 cm diameter) volume and count, and terrestrial and aquatic coarse woody debris (>9.9 cm diameter) volume were analyzed. Based on previous research, we hypothesized that sites with a higher …

Sensing Ribonuclease H Activity With Dna Nanoswitches, Ruju Trivedi

Biological Sciences

Ribonuclease H (RNase H) is a damage-repair protein and ribonuclease that specifically catalyzes the hydrolysis of RNA in an RNA/DNA duplex and breaks down RNA/DNA junctions. It plays an important role in a variety of biological processes including DNA replication, DNA repair, and transcription. It is also pivotal in anti-HIV drug development and the analysis of cellular processes and has been shown to be a potential therapeutic target for various neoplastic diseases. This thesis discusses a unique assay based on DNA nanoswitches to detect RNase H levels and activity. The assay is based on conformational changes of DNA nanoswitches in …

Understanding Intercellular Signaling During Lung Injury-Repair, Margo Patricia Cain

Dissertations and Theses (Open Access)

The mammalian lung is a complex system of specialized cell types with precise spatial organization designed to cooperate to perform gas exchange. These cell types together coordinate organ development, homeostasis, and repair after injury through signals either presented or secreted, known as ligands, to be received by receptors on the surface of another, or in some cases, the same cell. The alveolar region of the lung, the primary region of gas exchange, responds to various types of injuries with different lung repair mechanisms. In order to explore how the various cell types in the lung communicate to drive tissue repair …

Cd11b+ Depletion Of Bone Marrow Derived Macrophages Negatively Affects Bone Fracture Healing, Sarah Hozain

Seton Hall University Dissertations and Theses (ETDs)

Hematoma formation and inflammation occurs during the beginning stages of fracture repair, which require the presence of innate cells such as macrophages. Macrophages are subdivided into proinflammatory, M1, or anti-inflammatory, M2, phenotypes with different functions, cytokine profiles, and surface markers. In this study, in vitro and in vivo models were used to deplete M1 macrophages, using Mac-1 Sap conjugated antibody (Mac1SAP), to determine the effects on fracture healing. In vitro study, primary macrophages isolated from mice femoral bone marrow were harvested and differentiated into M1 macrophages (+LPS), M2 macrophages (+IL-4), or undifferentiated then treated with either vehicle or 10pM Mac1SAP. …