Cell and Developmental Biology Commons^™

Analyzation Of Metabolic Reprogramming In Drug-Resistant Mcf-7 Cells, Derick Han, Ho Leung, Andrew Vo

Student Scholar Symposium Abstracts and Posters

The Warburg effect states that cancer cells mainly receive their energy from anaerobic glycolysis. Thus, mitochondria play a different role in the metabolism of cancer cells as opposed to normal, healthy cells. In chemotherapy, there is always a chance of the cancer regressing. Making drug-resistant cancer cells to analyze their metabolism may change how cancer is treated. This study aimed to create drug-resistant MCF-7 cell lines with doxorubicin in order to determine the metabolic changes that have occurred in the process of becoming resistant to drug treatments.

Reverse Gyrase Is Not Necessary For Survival Of Hyperthermophilic Archaeon Pyrococcus Furiosus, Farshid Taghizadeh, Michael S. Bartlett

Student Research Symposium

Reverse gyrase is the only known topoisomerase enzyme with positive supercoiling activity on covalently-closed DNA. This positive supercoiling is required to prevent DNA from denaturation at high temperatures. The gene that codes for this protein is present in all hyperthermophiles and absent from all mesophilic and thermophilic genomes, suggesting that this enzyme is the only hyperthermophile-specific protein. To investigate if this protein is vital for the cells, we knocked out its gene from the genome of living organism Pyrococcus furiosus. Pyrococcus furiosus is a hyperthermophilic archaeon that grows between 70°C to 103°C with an optimum growth temperature of 100°C. …

Increased Airway Reactivity And Hyperinsulinemia In Obese Mice Are Linked By Erk Signaling In Brain Stem Cholinergic Neurons, Luiz O. S. Leiria, Fernanda M. Arantes-Costa, Marina C. Calixto, Eduardo C. Alexandre, Rodrigo F. Moura, Franco Folli, Carla M. Prado, Marco Antonio Prado, Vania F. Prado, Licio A. Velloso, Jose Donato Jr., Edson Antunes, Milton A. Martins, Mario J. A. Saad

Anatomy and Cell Biology Publications

Obesity is a major risk factor for asthma, which is characterized by airway hyperreactivity (AHR). In obesity-associated asthma, AHR may be regulated by non-T(H)2 mechanisms. We hypothesized that airway reactivity is regulated by insulin in the CNS, and that the high levels of insulin associated with obesity contribute to AHR. We found that intracerebroventricular (ICV)-injected insulin increases airway reactivity in wild-type, but not in vesicle acetylcholine transporter knockdown (VAChT KDHOM-/-), mice. Either neutralization of central insulin or inhibition of extracellular signal-regulated kinases (ERK) normalized airway reactivity in hyperinsulinemic obese mice. These effects were mediated by insulin in cholinergic nerves located …

Cytoskeletal Dynamics: A View From The Membrane, Magdalena Bezanilla, Amy S. Gladfelter, David R. Kovar, Wei-Lih Lee

Dartmouth Scholarship

Many aspects of cytoskeletal assembly and dynamics can be recapitulated in vitro; yet, how the cytoskeleton integrates signals in vivo across cellular membranes is far less understood. Recent work has demonstrated that the membrane alone, or through membrane-associated proteins, can effect dynamic changes to the cytoskeleton, thereby impacting cell physiology. Having identified mechanistic links between membranes and the actin, microtubule, and septin cytoskeletons, these studies highlight the membrane’s central role in coordinating these cytoskeletal systems to carry out essential processes, such as endocytosis, spindle positioning, and cellular compartmentalization.

Characterization Of The C. Elegans Nascent Polypeptide Associated Complex (Nac) Function Under Stress, Jonathan E. Sandoval

Masters Theses, 2010-2019

The nascent polypeptide-associated complex (NAC) is a highly conserved heterodimer known to play an important role in protein folding and localization during metazoan development. Evidence in different model systems indicates that removal of either subunit of the NAC, i.e. α- or β-NAC, is sufficient to generate misfolded protein stress in the endoplasmic reticulum (ER), resulting in the activation of the ER-specific unfolded protein response (UPR). What is not yet understood is the nature of the UPR depending on which subunit of the NAC is depleted. My research is focused on characterizing the specific UPR outcomes induced upon depletion of either …

Effect Of Cmvil-10 On Exosome Production By Human Breast Cancer Cells, Susanna N. Basappa

Undergraduate Honors Theses

Human cytomegalovirus (HCMV) is a ubiquitous virus that infects 70-90% of the general population, primarily the immunocompromised, but has been implicated in several forms of cancer, including breast cancer. Breast cancer is the second leading cause of cancer related deaths in women in North America, usually from metastasis. Exosomes are 30-100nm vesicles produced by most cells which carry protein and RNA to cells in their microenvironment. The aim of this study is to investigate the impact of HCMV-infection of a secreted viral cytokine, cmvIL-10, on exosome production by highly metastatic breast cancer cells.

MDA-MB-231 cells were cultured in vitro, …

Structural And Functional Interactions Between Bro1 Domain Of Human Alix Protein And Nucleocapsid Packaging Rna Complex From Hiv, Scott Gross

Graduate School of Biomedical Sciences Theses and Dissertations

A virus is only as powerful as its ability to spread. Enveloped retroviruses, namely HIV-1, use exocytosis pathways that normal host cells use to release particles from the plasma membrane. The main pathways of interest in this study are the Endosomal Sorting Complex Required for Transport (ESCRT) and adjacent ALIX pathways. The ESCRT pathway is especially important for degradation of receptor/cargo complexes that form Multi-Vesicular Bodies (MVBs). Currently, there is no known therapy that targets this endosomal pathway, which would prevent the spread of the virus to other cells. The virus has adapted to jump from pathway to pathway when …

Age-Dependent Breakdown Of The Blood Brain Barrier And Associated Changes In S100b Ko Mice, Eric V. Brown

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies play an important role in many autoimmune diseases. Recent research has shown that breakdown of the blood brain barrier (BBB) occurs concomitant to generation of brain reactive autoantibodies in many neurodegenerative diseases, which serve as biomarkers and drivers of pathology. SI00B, a calcium binding protein found most highly expressed in astrocytes which ensheathe the BBB, has many functions in neural development and signaling. Currently literature indicates that S100B KO mice develop normally, with no phenotypic abnormalities. Here, it is demonstrated that S100B KO mice seem to develop a chronic BBB breakdown similar to that seen in human neurodegenerative diseases. …

Hearing Sensitivity And The Effect Of Sound Exposure On The Axolotl (Ambystoma Mexicanum), Amy K. Fehrenbach

Masters Theses & Specialist Projects

The axolotl (Ambystoma mexicanum) has been used as a model organism for studying development, genetics, and regeneration. Although the sensory hair cells of the lateral line of this species have been shown to be able to regenerate, it is not known whether this also occurs in the inner ear. In fact, little is known about the hearing capabilities of the axolotl or other salamander species. I recorded auditory evoked potentials (AEPs) of six axolotls at eleven frequencies (0.1, 0.25, 0.4, 0.6, 0.8, 1, 1.5, 2, 3, 4, and 6 kHz) in order to produce baseline audiograms of underwater pressure sensitivity. …

Radium-223 For The Treatment Of Castration-Resistant Prostate Cancer, Joelle El-Amm, Jeanny B. Aragon-Ching

Medicine Faculty Publications

The vast majority of patients with metastatic castration-resistant prostate cancer (mCRPC) develop bone metastases. Bone metastases are a source of significant morbidity and affect quality of life in these patients. Several bone-targeting agents are approved for the treatment of bone metastases in prostate cancer, including bisphosphonates, denosumab, and radiopharmaceuticals. Radium-223 is a novel first-in-class alpha-emitting radiopharmaceutical that has been approved for treatment of patients with mCRPC with bone metastases. Radium-223 delivers cytotoxic radiation to the sites of bone metastases and offers the advantage of minimal myelosuppression. The landmark Phase III ALSYMPCA trial demonstrated that, in addition to providing bone-related palliation, …

Development Of Quantitative Tools For The Characterization And Analysis Of The Blood Brain Barrier In Normal And Mps Iiib Mice, Sara M. Rigney

Dissertations, Masters Theses, Capstones, and Culminating Projects

The Blood Brain Barrier (BBB) functions to control homeostasis within the central nervous system (CNS) via strict control over the passage of molecules into and out of the brain. The goal of this barrier is to protect the CNS from harmful external factors while allowing entry of essential nutrients and removal of metabolic byproducts. This restrictive nature of the BBB is due to the protein network at the borders of adjoining cerebral endothelial cells known as the tight junctions (TJs) and the relationship of other supporting cells and proteins such as astrocytes, pericytes, microglia, and the basement membrane and extracellular …

Discovering The Sequence Specificity Of Human Dyrk2 And Dyrk4, Julie Klaric

University Scholar Projects

Protein phosphorylation is a post-translational modification (PTM) that is ubiquitous in regulating cellular processes. It is the most common PTM used in signal translation. Protein kinases are the class of enzymes that catalyze the transfer of a phosphate group from ATP to a specific amino acid on a substrate protein. In eukaryotes, kinases generally add a phosphate to serine, threonine, or tyrosine residues. Short linear patterns in the amino acid sequence of the substrate protein help guide the protein kinase to the correct residue to be phosphorylated. However, these patterns, or “motifs,” as well as the complete list of substrates …

Growth Of Breast Tumors In Vitro To Characterize A Terahertz Imaging Platform, Scarlett-Marie Acklin

Biological Sciences Undergraduate Honors Theses

In this research, different methods were investigated to grow in-vitro breast cancer tumors embedded in gel using the 4T1 cell line. The goal of this research was to test a new medical imaging modality available at the University of Arkansas using terahertz (THz) waves. The THz imaging and spectroscopy system has shown capability of high-resolution imaging and characterization of human breast tumors fixed in formalin and embedded in paraffin. In order to further examine this new imaging system in a laboratory environment, attempts to grow breast tumors in-vitro were conducted. Results were produced in two different environments, flat-bottomed plates and …

Efficient In Vitro Development Of Photoreceptors From Human Pluripotent Stem Cells, Joseph C. Reynolds

Dissertations, Masters Theses, Capstones, and Culminating Projects

Degeneration of the rod and cone photoreceptors in the human retina is among the most common causes of blindness. Replacing these damaged photoreceptors may help to restore vision. Repairing the damaged retina relies on the insertion of new, healthy cells. Embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are two possible sources of photoreceptors to restore vision. Previous data shows that human ES cells and iPS cells can be differentiated into photoreceptors and transplanted into the eye to restore some vision. However, this process is inefficient, and costly. Here, we show a new method for inducing photoreceptor production …

Activating The Msh2/Msh6 Apoptotic Pathway In Cancer Cells Using Non-Reserpine Compounds, Jacob M. Mauceri

Honors College Theses

DNA mismatch repair (MMR) is a system that is highly conserved in both prokaryotes and eukaryotes. The heterodimeric protein MutSα and a suite of associated proteins are essential in the recognition and repair of DNA afflicted with mispaired bases and short insertion/deletion loops, but are also implicated in funneling damaged cells towards apoptosis via a key conformational change in a subunit of the MutSα complex. This conformation can be bound specifically by the small molecule reserpine. Molecular dynamics modeling and virtual screening were used to identify additional small molecule novel ligands with the predicted ability to selectively bind this “death” …

Characterization Of A Novel Clade Of Transporters In Phytophthora, Stephanie Padula, Paul F. Morris Dr, Howard Casey Cromwell Dr., Menaka Ariyaratne, Andrew Wagner

Honors Projects

The oomycete Phytophthora parasitica has a worldwide distribution and is an economically important pathogen of more than 100 species⁴. RNA-seq analysis showed that one gene, PPTG_16698 has the 5^th highest level of expression of all transport proteins in the zoospore stage, and is highly conserved throughout Phytophthora species. This project attempts to characterize the important biological role that PPTG_16698 plays in P. parasitica and other oomycetes. Three strategies have been implemented to accomplish this goal: growth analysis by heterologous expression in yeast, metabolite analysis in yeast, and construction of a GFP fusion protein to enable localization of …

The Effect Of High Terperature On Mating: Developmental Buffering Of S. Cerevisiae To The Environment, Sarah Hosie

Renée Crown University Honors Thesis Projects - All

In Saccharomyces cerevisiae, cellular polarization is an essential structural and functional aspect of growth and development. It is responsible for yielding and maintaining cellular asymmetry, and allows for cells to function. Mating in S. cerevisiae is a process that incorporates cell-to-cell signaling, signal transduction, cellular polarization, plasmogamy, karyogamy, and many other cellular processes. Each of these steps is mediated by a myriad of signaling proteins that are involved in a signaling cascade that is regulated by both extracellular and intracellular signals. Much is known about the mating process and pathway in S. cerevisiae. However, this project aimed to …

Overexpression And Gene Profiling Of Asparagine Synthetase In Hybrid Poplar, Kristopher Murray

Renée Crown University Honors Thesis Projects - All

Plants with polysaccharide-rich secondary cell walls have great potential as a source of carbohydrates for bioethanol production. However, the presence of phenolic lignin inhibits the isolation of bioethanol precursors cellulose and hemicellulose from the secondary cell wall. Recent studies have linked nitrogen availability to secondary cell wall development and composition, making nitrogen metabolism genes an interesting target in the improvement of plant cell walls for biofuels production. Plants use a nitrogen assimilation pathway to convert inorganic nitrogen sources into organic sources, included amino acids, which play key roles in metabolism and cell wall development. Asparagine synthetase (AS), a key enzyme …

Characterization Of Ghrelin O-Acyltransferase Active Site, Leslie Patton

Renée Crown University Honors Thesis Projects - All

Ghrelin, first discovered in 1999, is a 28-amino acid peptide hormone involved in the regulation of appetite, insulin secretion and sensitivity, and many neurological effects such as learning, memory, and depression.^1-6 Ghrelin has been identified to have a unique posttranslational octanoylation carried out by the enzyme ghrelin O-acyltransferase (GOAT). This distinctive modification is a point of interest in studying GOAT whereby blocking the acylation of the ghrelin could potentially halt the activity of the peptide hormone and provide a means of treating obesity, diabetes, and other diseases affected by ghrelin levels. The duration of my project involved working …

Role Of Ribosomal Biogenesis In Axonal Morphogenesis., Nicholas Mcchesney Lynch

College of Arts & Sciences Senior Theses

Elongating axons require a host of macromolecules for outgrowth. The importance of lipid, protein, and general RNA synthesis for initial axonal growth has been previously investigated, but the role of rRNA synthesis and ribosome production in axonal morphogenesis remains unclear. Therefore, rat hippocampal neurons were cultured and transfected with shRNA against either TIF-IA (the activator of RNA polymerase I) or RPS6 (a small ribosomal subunit component) to determine the effects of impaired de novo ribosome synthesis on axonal development during the first three days after plating. Our data show that shRPS6 weakly inhibited total axon length, but not longest axon …