Cell and Developmental Biology Commons^™

A Model Of How Different Biology Experts Explain Molecular And Cellular Mechanisms, Caleb M. Trujillo, Trevor R. Anderson, Nancy J. Pelaez

PIBERG Publications

Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do explanations made by experts from different biology subdisciplines at a university support the validity of this model? Guided by the modeling framework of R. S. Justi and J. K. Gilbert, the validity of an initial model was tested by asking seven biologists to explain a molecular …

Chronic Inflammation As A Result Of Hepatitis C Virus Infection: A Review Of The Literature, Samantha L. Lane

DePaul Discoveries

Approximately 170 million people are infected with Hepatitis C virus (HCV) worldwide^5,6. It is estimated that roughly 80% of those infected suffer from persistent infection with the virus; this persistence of infection is progressive, and over time can lead to fibrosis, cirrhosis, and hepatocellular carcinoma⁷. Chronic inflammation and apoptotic deregulation are both hallmarks of chronic HCV infection, and many molecular pathways are initiated in both the innate and adaptive immune responses during infection with this viral pathogen. The aim of this review was to survey some of the major molecular mechanisms responsible for the induction of …

The Effects Of Sustained, High-Velocity Exercise On Gene Expression In California Yellowtail (Seriola Lalandi), Kelli Hatter

Undergraduate Honors Theses

California Yellowtail muscle fibers have been observed to exhibit two drastically different development patterns resulting from the speeds at which they are exercised. When fish are exercised at a moderate rate their epaxial fast-twitch muscle fibers grow in diameter—hypertrophy; when they are exercised at a fast speed, more new epaxial fast-twitch muscle fibers are produced—hyperplasia. To determine the underlying reason for this difference in muscle development, my summer research project and honors thesis exercised fish at: fast, moderate, and control speeds for a sustained amount of time to determine what is happening on a cellular level to cause the observed …

Expressing And Characterizing Mechanosensitive Channels In Xenopus Oocytes, Grigory Maksaev, Elizabeth S. Haswell

Biology Faculty Research

The oocytes of the African clawed frog (Xenopus laevis) comprise one of the most widely used membrane protein expression systems. While frequently used for studies of transporters and ion channels, the application of this system to the study of mechanosensitive ion channels has been overlooked, perhaps due to a relative abundance of native expression systems. Recent advances, however, have illustrated the advantages of the oocyte system for studying plant and bacterial mechanosensitive channels. Here we describe in detail the methods used for heterologous expression and characterization of bacterial and plant mechanosensitive channels in Xenopus oocytes.

Environmental Stimuli And Intragenerational Epigenetics, Nicholas J. Napier

Student Scholarship

Epigenetics is the study of any change in gene expression that is not mediated by DNA sequence. The effects of environmental stimuli on epigenetic changes have been studied extensively in recent years. Multiple reviews have provided comprehensive summations of the effects of environmental stimuli on transgenerational epigenetic changes, but few reviews have focused upon environment-induced intragenerational epigenetic changes. This review will summarize current knowledge of the intragenerational epigenetic changes that are induced by two groups of well-studied environmental stimuli: nutritional deficiencies and carcinogens. This survey of intragenerational epigenetic changes will focus upon the mechanisms behind them, the disorders associated with …

Alternate Formulations For Optimization Of Plga Microsphere-Comprised Glucose Biosensor Coating Against Foreign Body Inflammation., Klair Lubonja

Honors Scholar Theses

In this study, dexamethasone loaded PLGA microsphere/PVA hydrogel composites were explored as an outer drug-eluting coating for implantable biosensors to provide defense against acute inflammation of the foreign body response. The microspheres, with a dexamethasone release target period of approximately two weeks, were manufactured under various conditions: different co-solvents and homogenization speeds. Particle size measurement, scanning electron microscopy and differential scanning calorimetry were performed for all the microsphere formulations prepared. The addition of acetone as a co-solvent for dexamethasone, at normal homogenization speeds, shows promise for the improvement of drug loading and the attainment of superior release profiles. PLGA microsphere/PVA …

Characterization And Transplantation Of Felid Spermatogonial Stem Cells, Robin H. Powell

LSU New Orleans Theses and Dissertations

Spermatogonial stem cells (SSC) self-renew and differentiate into spermatozoa throughout the life of the male. SSC transplantation is a potential method for the propagation of genetically important males. These cells have been isolated in different mammalian species using specific cell surface markers, but not in felines.

The goal of this study was to explore a relevant strategy for conservation of endangered felids by characterizing domestic cat (Felis catus) SSCs and assessing their ability for self-renewal after transplantation. Firstly, SSC and pluripotent surface markers, identified in non-feline species, were tested for expression in mixed germ cells from adults by …

Prostate Field Cancerization – Thinking Outside The Tumor, Dor Shoshan

Student Scholar Symposium Abstracts and Posters

Analysis of tumor adjacent tissue is assumed to reveal a temporal record of molecular pathways that define oncogenesis. The present study determines expression of the key transcription factor and potential marker of field cancerization early growth response 1 (EGR-1) in human prostate tissues derived from prostatectomies and biopsies. Expression was detected using immunofluorescence and quantified using ImageJ software. Accordingly, EGR-1 expression was similar in cancerous and in histologically normal adjacent tissues from prostatectomy and biopsy specimens. EGR-1 could be exploited as pre-surgical disease indicator in false negative biopsies, identify areas of repeat biopsy, and add molecular information to surgical margins.

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.

Clinical Applications Of A Combination Chemotherapy Using 8-Chloro Camp And 8-Chloro Adenosine, Erik Munoz, Andrea Saich, Andrew Cox, Yu-An Peter Chang

Student Scholar Symposium Abstracts and Posters

Dr. Cho-Chung from the NIH first thought to use halogenated cAMP derivatives as competitive inhibitors of cAMP to slow down cancer cell mitosis. While the iodine and bromine substituted versions showed very little therapeutic actions, 8-Chloro cAMP has been shown to have strong anti-cancer effects. This has been shown in the phase II clinical trials this drug has undergone. However, these trials have had issues with solubility and toxicity. The drug is similar to vitamin C and is excreted quickly. Scientists tried to overcome this by using a peristaltic pump to give patients a continuous dosage, but this proved too …

Exploring Egr-1 As A Master Regulator Of Prostate Field Cancerization, Kristin Gabriel, Marco Bisoffi

Student Scholar Symposium Abstracts and Posters

Field cancerization denotes the presence of molecular aberrations (genetic, epigenetic, biochemical) in structurally intact cells residing in histologically normal tissues adjacent to tumors. Markers of field cancerization in prostate tissues have the potential to improve the clinical management of this malignancy through their potential to act as indicators of early disease and to serve as molecular targets for early intervention. However, for this, a detailed understanding of the functional pathways underlying field cancerization is necessary. We have recently identified four protein markers of prostate field cancerization, i.e. the key transcription factor early growth response 1 (EGR-1), the lipogenic enzyme fatty …

Effect Of Curcumin Analog Ca27 On Androgen Receptor Translocation In Prostate Cancer Cells, Lijah Vann Gardner

Student Scholar Symposium Abstracts and Posters

The androgen receptor (AR) plays an essential role in promoting the development and progression of metastatic prostate cancer and represents an important molecular target for therapeutic intervention. We have recently described a series of synthetic analogs of the natural product diferuloylmethane (curcumin), some of which induce the down-regulation of AR expression in prostate cancer cells by an as yet largely unknown mechanism of action. While such analogs may in the long term be lead structures for the development of therapeutic drugs, we hypothesize here that they represent ideal molecular probes to identify the mechanism(s) of action for AR down-regulation. We …

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 …

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 …

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 …

Deciphering The Functional Collaboration Of Mid And Bric-A-Brac 2 As Potential Regulators Of Cellular Proliferation Within Adult Drosophila Ovaries, Petra Visic

Master's Theses

Stem cell niches are highly organized and specialized microenvironments located within specific tissues of both vertebrate and invertebrate organisms [1]. In Drosophila melanogaster, three distinct stem cell niches have been identified within the ovary including the germline stem cell (GSC), follicle stem cell (FSC), and escort stem cell (ESC) niche. Recently, Fregoso-Lomas et al. [2] reported that Gurken/Epidermal Growth Factor Receptor (EGFR) signaling is modulated within posterior ovarian follicle cells by Midline (Mid). The mid gene encodes a T-box transcription factor protein that specifies cell fates in the developing heart [3][4], central nervous system [5][6], epidermis [7], and eye …

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 …

The Reproductive Ecology Of The Timber Rattlesnake, Crotalus Horridus, In Northwestern Arkansas: Interactions Between Environment, Steroid Hormones, And Life History, Craig Michael Lind

Graduate Theses and Dissertations

In this dissertation I examined the relationship between individual energetic status, hormone production, and life history trait expression in field-active Timber Rattlesnakes, Crotalus horridus. In chapter one I reviewed what is known regarding these relationships in snakes and defined major research goals. In chapter two I described the seasonal profile of testosterone (T) and corticosterone (CORT) in relation to the breeding season and to individual energetic status in males. Results showed that the seasonal pattern of T production in C. horridus was different than other pit viper species with similar mating patterns. Testosterone was elevated in the months leading up …

Progressive Decline Of Testicular Function In Leptinreceptor Deficient Obese Mice, Jennifer Long

Masters Theses

The incidence of obesity and metabolic syndrome among the human population is increasing, but the effects on male fertility are unresolved. Leptin insensitivity appears to show a consistent relationship between obesity and fertility problems in men. Genetically modified mice lacking the leptin hormone (ob/ob) or leptin receptor (db/db) are reported to be subfertile and/or infertile but there is only minimal information about testicular function (sperm and hormone production) and the progression of infertility. Therefore, this study was designed to investigate testicular function using a leptin-receptor-deficient obese mouse model (the POUND mouse; Charles River). Testicular sperm production is reduced in POUND …

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 …