Cell Biology Commons^™

Microglia Polarize In Response To Transactive Response Dna-Binding Protein-43 (Tdp-43) And Display Partial Recovery After Removal Of The Stimulus, Alicen Wilcox

Honors Theses

The proper response to protein signals is necessary for a healthy central nervous system (CNS), and protein dysregulation is a feature of neurodegenerative diseases. Transactive response DNA-binding protein-43 (TDP-43) is an intranuclear protein, but mislocalization is associated with amyotrophic lateral sclerosis (ALS). TDP-43 is released into the extracellular space where it is sensed by microglia, the CNS-resident immune cells. Our data and the literature suggest that microglia respond to TDP-43 dysregulation by increasing CNS inflammation. The goal of this study was to determine the impact of TDP-43 on microglial function and the extent to which microglia recovery. To study the …

The Effects Of Ppal-1 In Arabidopsis Gamete Development, Amanda J White, Susana Perez-Martinez, Mark P. Running

The Cardinal Edge

Prenylation is a type of post-translational modification in which a 15- or 20-carbon lipid is added to the carboxyl (C) terminus of the protein. Arabidopsis thaliana contains the PROTEIN PRENYLTRANSFERASE ALPHA SUBUNIT-LIKE (PPAL) gene, which encodes a protein with homology to the α-subunits of the three known prenylation enzymes, PFT, PGGT, and Rab-GGT. We previously identified two mutations in PPAL, one of which is ppal-1, which contains a T-DNA insertion in the fourth intron. We have previously observed that self-fertilizing heterozygous ppal-1 plants produce progeny in which homozygous ppal-1 is underrepresented. This project attempts to ascertain …

Phenotypic/Genotypic Profile Of Oxa-10-Like-Harboring, Carbapenem-Resistant Pseudomonas Aeruginosa: Using Validated Pharmacokinetic/Pharmacodynamic In Vivo Models To Further Evaluate Enzyme Functionality And Clinical Implications, Fred C. Tenover, Christian M. Gill, Adrian Brink, Chun Yat Chu, Jennifer Coetzee, George Dimopoulos, Clinton Moodley, Christoffel Johannes Opperman, Spyros Pournaras, Isabella A. Tickler, Hafsah Deepa Tootla, Sophia Vourli, David P. Nicolau

Biology Faculty Publications

In vitro MICs and in vivo pharmacodynamics of ceftazidime and cefepime human-simulated regimens (HSR) against modified carbapenem inactivation method (mCIM)-positive Pseudomonas aeruginosa isolates harboring different OXA-10-like subtypes were described. The murine thigh model assessed ceftazidime (2 g every 8 h [q8h] HSR) and cefepime (2 g and 1 g q8h HSR). Phenotypes were similar despite possessing OXA-10-like subtypes with differing spectra. Ceftazidime produced ≥1-log10 killing in all isolates. Cefepime activity was dose dependent and MIC driven. This approach may be useful in assessing the implications of β-lactamase variants.

Proteoglycan-4 Is An Essential Regulator Of Synovial Macrophage Polarization And Inflammatory Macrophage Joint Infiltration, Marwa Qadri, Gregory D. Jay, Ling X. Zhang, Tannin A. Schmidt, Jennifer Totonchy, Khaled A. Elsaid

Pharmacy Faculty Articles and Research

Background

Synovial macrophages perform a multitude of functions that include clearance of cell debris and foreign bodies, tissue immune surveillance, and resolution of inflammation. The functional diversity of macrophages is enabled by distinct subpopulations that express unique surface markers. Proteoglycan-4 (PRG4) is an important regulator of synovial hyperplasia and fibrotic remodeling, and the involvement of macrophages in PRG4’s synovial role is yet to be defined. Our objectives were to study the PRG4’s importance to macrophage homeostatic regulation in the synovium and infiltration of pro-inflammatory macrophages in acute synovitis and investigate whether macrophages mediated synovial fibrosis in Prg4 gene-trap (Prg4 …

Design And Application Of Hybrid Cyclic-Linear Peptide-Doxorubicin Conjugates As A Strategy To Overcome Doxorubicin Resistance And Toxicity, Saghar Mozaffari, David Salehi, Parvin Mahdipoor, Richard Beuttler, Rakesh Tiwari, Hamidreza Montazeri Aliabadi, Keykavous Parang

Pharmacy Faculty Articles and Research

Doxorubicin (Dox) is used for breast cancer, leukemia, and lymphoma treatment as an effective chemotherapeutic agent. However, Dox use is restricted due to inherent and acquired resistance and an 8-fold increase in the risk of potentially fatal cardiotoxicity. Hybrid cyclic-linear peptide [R5K]W7A and linear peptide R5KW7A were conjugated with Dox through a glutarate linker to afford [R5K]W7A-Dox and R5KW7A-Dox conjugates to generate Dox derivatives. Alternatively, [R5K]W7C was conjugated with Dox via a disulfide linker to generate [R5K]W7C–S–S-Dox conjugate, where S–S is a disulfide bond. Comparative antiproliferative assays between conjugates [R5K]W7A-Dox, [R5K]W7C–S–S-Dox, linear R5KW7A-Dox, the corresponding physical mixtures of the peptides, …

Mechanisms Of Substrate Recognition By The Cul3-Based E3 Ligase, Katia Graziella De Oliveira Rebola

Dissertations and Theses

Cul3-based E3 ligase is responsible for regulating a variety of cellular pathways, many of which are known to have profound effects on the proper function of multicellular organisms. Although progress over the past years has been truly impressive, our understanding of the mechanisms of E2 recruitment and selection by the BCR complex and all the roles that Cul3 plays on kidneys remains in its infancy. To explore these aspects, this dissertation aims to analyze the Cul3 complex using two different approaches: (1) We used the powerful tool of chimeric analysis to map the essential domain binding characteristics of Cul3 taking …

Study Of The Gain-Of-Function Mutant P53 And Parp1 In Triple-Negative Breast Cancer, Devon Lundine

Dissertations, Theses, and Capstone Projects

Cancer cells often lose expression of the p53 protein or express mutant forms of p53. Some of these mutant p53 proteins, called gain-of-function mutant p53, have gained oncogenic functions. Previously, our group observed mutant p53 R273H interacts with replicating DNA and upregulates the chromatin localization of several DNA replication factors including PCNA, MCM2-7, and PARP1 (termed the mtp53-PARP-MCM axis). In this thesis, we explore the contribution of mutant p53 and PARP1 in castration-resistant prostate cancer (mutant p53 P223L and V274F) and triple-negative breast cancer (mutant p53 R273H). In the castration-resistant prostate cancer cell line DU145, we examine two mutant p53 …

The Structural And Functional Role Of Photosensing In Rgs-Lov Proteins, Zaynab Jaber

Dissertations, Theses, and Capstone Projects

Light provides organisms with energy and spatiotemporal information. To survive and adapt, organisms have developed the ability to sense light to drive biochemical effects that underlie vision, entrainment of circadian rhythm, stress response, virulence, and many other important molecularly driven responses. Blue-light sensing Light-Oxygen-Voltage (LOV) domains are ubiquitous across multiple kingdoms of life and modulate various physiological events via diverse effector domains. Using a small molecule flavin chromophore, the LOV domain undergoes light-dependent structural changes leading to activation or repression of these catalytic and non-catalytic effectors. In silico analyses of high-throughput genomic sequencing data has led to the marked expansion …

Analysis Of Transplantable Photoreceptor Replacement Cell Chemotactic Mechanisms In Retinal Biomimetic Ligand Gradients, Onyekwere Onwumere

Dissertations, Theses, and Capstone Projects

Disease or trauma induced loss of rod and cone photoreceptors is a major cause of vision loss worldwide. To replace lost photoreceptors and restore vision, laboratories around the world are investigating photoreceptor replacement strategies using subretinal injection of photoreceptor precursor cells (PPCs) and retinal progenitor cells (RPCs). A major obstacle in the field is that transplanted photoreceptor replacement cells exhibit extremely limited migration into host retina following injection into the subretinal space. In this work, we show that PPCs and host retinal interaction bioinformatics modeling can identify key pathways involved in photoreceptor replacement cell migration and invasion behaviors. In addition, …

Synthesis, Characterization And Applications Of Peptide-Coated Nanoparticles, Mina Sadat Poursharifi

Dissertations, Theses, and Capstone Projects

Ovarian Cancer (OC) is the most lethal female malignancy worldwide, mainly due to its high recurrence rate and poor diagnosis. Most patients present with late stage of the disease, and less than 25% of patients survive the five years mark. Nanotherapy provides significant and unique benefits for drug efficacy, as nanoparticles (NPs) can increase the solubility, bioavailability, and permeability of many potent drugs. Poly(lactic-co-glycolic acid) (PLGA) is one of the most successful biodegradable polymers used in NPs formulations, mainly due to its biocompatibility and biodegradability. Polyethylene glycol (PEG) is one of the most commonly used moieties to prolong the NPs …

Complimenting A Chlamydomonas Reinhardtii Mutation Using Cell Penetrating Peptides, Matthew Mckenzie

Symposium of Student Scholars

Complimenting a Chlamydomonas reinhardtii Mutation Using Cell Penetrating Peptides

Matthew McKenzie and Jennifer L. Cooper

Chlamydomonas reinhardtii is a photosynthetic model organism most notable for its easily manipulatable genetics. C. reinhardtii uses flagella to swim and optimize its growth conditions in the light. We plan to use cell penetrating peptides (CPPs) to compliment C. reinhardtii that is affected with the IFT46 mutation. Cell penetrating peptides are short peptides that can move across a cell membrane. The novel CPP that we are using is called TaT-CaM. It consists of the trans-activator of transcription (TaT) and the calmodulin domain (CaM) that binds …

The Role Of Proneural Transcription Factor Ngn-1/Neurogenin During Caenorhabditis Elegans Embryonic Development, Michaela Diane Crego

Symposium of Student Scholars

Accurate control of neuronal cell identification and movement is crucial to embryonic development. Defects in this process can lead to neurodevelopmental disorders, creating an imperative for further study. The transcription factor neurogenin is required for multiple neurodevelopmental processes during vertebrate embryonic development and mutations in this gene underpin multiple human neurological disorders. Despite this, little is known about how this gene controls nervous system development and function. Neurogenin is deeply conserved across phyla. As such, we can investigate neurogenin function in simple systems such as the nematode Caenorhabditis elegans, which has a close ortholog of neurogenin, ngn-1. Previous work in …

Threshold Concentration And Random Collision Determine The Growth Of The Huntingtin Inclusion From A Stable Core, Sen Pei, Theresa C. Swayne, Jeffrey F. Morris, Lesley Emtage

Publications and Research

The processes underlying formation and growth of unfolded protein inclusions are relevant to neurodegenerative diseases but poorly characterized in living cells. In S. cerevisiae, inclusions formed by mutant huntingtin (mHtt) have some characteristics of biomolecular condensates but the physical nature and growth mechanisms of inclusion bodies remain unclear. We have probed the relationship between concentration and inclusion growth in vivo and find that growth of mHtt inclusions in living cells is triggered at a cytoplasmic threshold concentration, while reduction in cytoplasmic mHtt causes inclusions to shrink. The growth rate is consistent with incorporation of new material through collision and coalescence. …

Human Ipsc Tissue-Engineered Cartilage For Disease Modeling Of Skeletal Dysplasia-Causing Trpv4 Mutations, Amanda R. Dicks

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cartilage is essential to joint development and function. However, there is a variety of cartilage diseases, ranging from developmental (e.g., skeletal dysplasias) to degenerative (e.g., arthritis), in which treatments and therapeutics are lacking. For example, specific point mutations in the ion channel transient receptor potential vanilloid 4 (TRPV4) prevent proper joint development, leading to mild brachyolmia and severe, neonatally lethal metatropic dysplasia. Tissue-engineered cartilage offers an opportunity to elucidate the underlying mechanisms of these cartilage diseases for the development of treatments. Human induced pluripotent stem cells (hiPSCs) are an improved cell source option for cartilage tissue engineering given their minimal …

Characterization Of Metabolic Gene Expression In The Raw 264.7 Monocyte Cell Line, Lauren Macaisa

PANDION: The Osprey Journal of Research and Ideas

Immune cells undergo changes in gene expression and metabolism when activated by a foreign molecule. Although the changes are short-lived in response to an acute infection, they persist in disorders with underlying chronic inflammation. To understand how changes in gene expression relate to changes in metabolism, the expression of metabolic transporter proteins, was analyzed in response to chronic inflammation in a mouse monocyte cell line. Specifically, Glucose Transporter-1 (GLUT1), Monocarboxylate Transporter-1 (MCT1), Monocarboxylate Transporter-4 (MCT4), and Glutamate Aspartate Transporter (GLAST) were analyzed, and it was hypothesized that all the transporters would increase in expression in response to a prolonged inflammatory …

Unbiased Automated Quantitation Of Ros Signals In Live Retinal Neurons Of Drosophila Using Fiji/Imagej, Prajakta Deshpande, Neha Gogia, Anuradha Venkatakrishnan Chimata, Amit Singh

Biology Faculty Publications

Numerous imaging modules are utilized to study changes that occur during cellular processes. Besides qualitative (immunohistochemical) or semiquantitative (Western blot) approaches, direct quantitation method(s) for detecting and analyzing signal intensities for disease(s) biomarkers are lacking. Thus, there is a need to develop method(s) to quantitate specific signals and eliminate noise during live tissue imaging. An increase in reactive oxygen species (ROS) such as superoxide (O2•-) radicals results in oxidative damage of biomolecules, which leads to oxidative stress. This can be detected by dihydroethidium staining in live tissue(s), which does not rely on fixation and helps prevent stress on tissues. However, …

Investigations In The Cellular And Molecular Biology Of Human Airway Mucociliary Tissue, Vincent Manna

Graduate School of Biomedical Sciences Theses and Dissertations

Our laboratory has integrated the use of a human-derived, in vitro model of airway mucociliary tissue. We isolate human nasal epithelial cells (HNECs) from the nasal mucociliary tissue of donors with a small brush and expand the airway progenitor cells in culture. The HNECs are then seeded onto semi-permeable transwell inserts. The inserts are in contact with the media in the lower chamber but don’t contain media in the upper chamber therefore the cells are exposed to the air while drawing nutrients from the media below, this is called the Air-Liquid Interface (ALI). HNECs cultured at the ALI initiate a …

Effects Of Trans-Acting Factors On The Translational Machinery In Yeast, Brandon M. Trainor

Graduate School of Biomedical Sciences Theses and Dissertations

Synthesis of proteins, or translation, is a complex biological process requiring the coordinated effort of numerous protein and RNA factors. Central to translation is the ribosome, a complex macromolecular complex consisting of both ribosomal RNA (rRNA) and ribosomal protein (r-protein). Ribosomes are essential and are one of the oldest and most abundant biomolecules across all forms of life. In addition to the ribosome, translation requires messenger RNA (mRNA), transfer-RNA conjugated to an amino acid (aa-tRNA), translation factors, and energy in the form of ATP and GTP. Translation universally occurs in four major stages, initiation, elongation, termination, and recycling, with initiation …

Epithelial Memory Of Resolved Inflammation Limits Tissue Damage While Promoting Pancreatic Tumorigenesis, I-Lin Ho

Dissertations and Theses (Open Access)

Inflammation is a major risk factor for pancreatic ductal adenocarcinoma. When occurring in the context of pancreatitis, mutations of KRAS accelerate tumor development. We discovered that long after its complete resolution, a transient inflammatory event primes pancreatic epithelial cells to subsequent transformation by oncogenic KRAS. Upon recovery from acute inflammation, epithelial cells of the pancreas display an enduring adaptive response associated with sustained transcriptional and epigenetic reprogramming. Such adaptation enables the prompt reactivation of acinar-to-ductal metaplasia (ADM) upon subsequent inflammatory events, thus efficiently limiting tissue damage via rapid decrease of zymogen production. We propose that since activating mutations of KRAS …

Targeting Plasma Membrane Phosphatidylserine Content To Inhibit Oncogenic Kras Function, Walaa E. Kattan

Dissertations and Theses (Open Access)

The small GTPase KRAS, which is frequently mutated in human cancers, must be localized to the plasma membrane (PM) for biological activity. We recently showed that the KRAS C-terminal membrane anchor exhibits exquisite lipid-binding specificity for select species of phosphatidylserine (PtdSer). We therefore investigated whether reducing PM PtdSer content is sufficient to abrogate KRAS oncogenesis. Oxysterol-related binding proteins ORP5 and ORP8 exchange PtdSer synthesized in the ER for phosphatidylinositol-4-phosphate (PI4P) synthesized in the PM. We show that depletion of ORP5 or ORP8 reduced PM PtdSer levels, resulting in extensive mislocalization of KRAS from the PM. Concordantly, ORP5 or ORP8 depletion …

Anatomy And Physiology Preparatory Course Textbook (2nd Edition), Carlos Liachovitzky

Open Educational Resources

The goal of this preparatory textbook is to give students a chance to become familiar with some terms and some basic concepts they will find later on in the Anatomy and Physiology course, especially during the first few weeks of the course.

Organization and functioning of the human organism are generally presented starting from the simplest building blocks, and then moving into levels of increasing complexity. This textbook follows the same presentation. It begins introducing the concept of homeostasis, then covers the chemical level, and later on a basic introduction to cellular level, organ level, and organ system level. This …

Nucleotide P2y₂ Receptor-Dependent Leukocyte-Endothelial Interaction, Spencer E. Thomas

Graduate Theses/Dissertations

Extracellular nucleotides (ATP, UTP) released from cells act on nucleotide receptors to promote vascular inflammation. Increased leukocyte-endothelial interaction is a hallmark of vascular inflammation. The nucleotide P2Y₂ receptor (P2Y₂R), activated by extracellular ATP≈UTP, plays a role in cardiovascular homeostasis and immune regulation. Moreover, accumulating evidence from studies in vitro and in vivo models have implicated the P2Y₂R in the inflammatory response significantly contributing to the progression and pathogenesis of asthma, atherosclerosis, sepsis, and ischemia. I hypothesized that P2Y₂R activation by UTP, an agonist of the receptor, increased leukocyte rolling and adhesion in the microvasculature from baseline. To test the hypothesis, …

Neuronal Migration In Developmental Hyperserotonmia: Assessment Of Vesicular Glutamate In The Raphe Nuclei, Trey M. Shupp

Graduate Theses/Dissertations

The neurotransmitter serotonin is involved in the early development of the central nervous system and the organization of neurons throughout the cerebral cortex and cerebellum. It is proposed that serotonin indirectly interacts with cells in the marginal zone of the cerebral cortex known as Cajal-Retizus (CR) cells. These cells secrete the extracellular matrix protein reelin, which is known for its role in neuronal organization and migration during early neural development. It has been observed that low levels of serotonin are associated with similarly low levels of reelin during development and have been reported to result in disorganization of neurons in …

An Assessment Of Inp/Zns As Potential Anti-Cancer Therapy: Quantum Dot Treatment Induces Stress On Hela Cells, Victoria Grace Davenport

Graduate Theses/Dissertations

Indium Phosphide/Zinc Sulfide (InP/ZnS) quantum dots (QDs) are an emerging option in QD technologies for uses of fluorescent imaging as well as targeted drug and anti-cancer therapies based on their customizable properties. In this study we explored effects of InP/ZnS when treated with HeLa cervical cancer cells. We employed XTT viability assays, reactive oxygen species (ROS) analysis, and apoptosis analysis to better understand cytotoxicity extents at different concentrations of InP/ZnS. In addition, we compared the transcriptome profile from the QDtreated HeLa cells with that of untreated HeLa cells to identify changes to the transcriptome in response to the QD. Intracellular …

The Functional Analysis Of A Major Tyrosine Phosphorylation Site On Actin, Amelie Simone Cordelia Albrecht

Dissertations and Theses (Open Access)

Actin is an abundant and evolutionarily conserved protein and a key component of the cytoskeleton. Post-translational modifications of actin are emerging as an important mechanism for regulating actin functions, and may form an ‘Actin Code’. In this work, I investigate the role of actin phosphorylation at tyrosine 53 (pY53), one of the most frequently detected actin PTMs, through identifying interaction partners, or ‘readers’, for this modification. Using an SH2 (Src Homology 2) protein domain array, we identify N-terminal SH2 domains of p85, regulatory subunits of Phosphatidylinositol 3-kinase (PI3K), and VAV2, a Rho GTPase guanine nucleotide exchange factor, as phosphorylation-dependent binding …

Bone Morphogenetic Protein Signaling Requirement In Centripetal Migration In Drosophila Melanogaster Oogenesis, Sheila Mosallaei

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cells interact with each other via signals to coordinate migration for proper tissue development and maintenance, immunity and tissue repair. Signals regulate migration via changes to cytoskeletal components or transcriptional regulation. Here, I used Drosophila melanogaster to investigate whether and how a transcriptional signal, Bone Morphogenetic Protein signaling, drives a cell migration, centripetal migration. The migrating cells, centripetal follicle cells, consist of two subsets of cells, “leading” and “following” centripetal follicle cells, that although adjacent to each other, migrate differently. The differences in modes of migration correlate to differential gene expression in the centripetal follicle cells. The leading centripetal follicle …

The Effect Of Sub 5% Oxygen Tension On In Vitro Human Embryo Development, Bradley James Link

EVMS School of Health Professions Theses & Dissertations

Objective: To determine the impact of < 5% O₂ tension on the in vitro development of human pre-implantation embryos. It was hypothesized that the optimal O₂ tension would differ from the commonly utilized 5%, as shown by beneficial effects after the implementation of a more physiological O₂ tension such as 2% for either the partial or full duration of in vitro culture.

Aim: To conduct a randomized controlled study to determine the effect of O₂ tension during in vitro human embryo culture on the production of reactive oxygen species (ROS), apoptosis, gene expression and embryo development.

Background: The …

Suppression Of Dc-Sign And Gh Reveals Complex, Subset-Specific Mechanisms For Kshv Entry In Primary B Lymphocytes, Nancy Palmerin, Farizeh Aalam, Romina Nabiee, Murali Muniraju, Javier Gordon Ogembo, Jennifer Totonchy

Pharmacy Faculty Articles and Research

Kaposi sarcoma-associated herpesvirus (KSHV) is the causative agent of multiple cancers in immunocompromised patients including two lymphoproliferative disorders associated with KSHV infection of B lymphocytes. Despite many years of research into the pathogenesis of KSHV associated diseases, basic questions related to KSHV molecular virology remain unresolved. One such unresolved question is the cellular receptors and viral glycoproteins needed for KSHV entry into primary B lymphocytes. In this study, we assess the contributions of KSHV glycoprotein H (gH) and the cellular receptor DC-SIGN to KSHV infection in tonsil-derived B lymphocytes. Our results show that (1) neither KSHV-gH nor DC-SIGN are essential …

Bcr Affinity Influences T-B Interactions And B Cell Development In Secondary Lymphoid Organs, Alec J. Wishnie, Tzippora Chwat-Edelstein, Mary Attaway, Bao Q. Vuong

Publications and Research

B cells produce high-affinity immunoglobulins (Igs), or antibodies, to eliminate foreign pathogens. Mature, naïve B cells expressing an antigen-specific cell surface Ig, or B cell receptor (BCR), are directed toward either an extrafollicular (EF) or germinal center (GC) response upon antigen binding. B cell interactions with CD4+ pre-T follicular helper (pre- Tfh) cells at the T-B border and effector Tfh cells in the B cell follicle and GC control B cell development in response to antigen. Here, we review recent studies demonstrating the role of B cell receptor (BCR) affinity in modulating T-B interactions and the subsequent differentiation of B …

Dimeric Allostery Mechanism Of The Plant Circadian Clock Photoreceptor Zeitlupe, Francesco Trozzi, Feng Wang, Gennady M. Verkhivker, Brian D. Zoltowski, Peng Tao

Mathematics, Physics, and Computer Science Faculty Articles and Research

In Arabidopsis thaliana, the Light-Oxygen-Voltage (LOV) domain containing protein ZEITLUPE (ZTL) integrates light quality, intensity, and duration into regulation of the circadian clock. Recent structural and biochemical studies of ZTL indicate that the protein diverges from other members of the LOV superfamily in its allosteric mechanism, and that the divergent allosteric mechanism hinges upon conservation of two signaling residues G46 and V48 that alter dynamic motions of a Gln residue implicated in signal transduction in all LOV proteins. Here, we delineate the allosteric mechanism of ZTL via an integrated computational approach that employs atomistic simulations of wild type and …