Cell Biology Commons^™

The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers

Electronic Theses and Dissertations

Primordial germ cells (PGCs) are hypothesized to deposit hematopoietic stem cells (HSCs) along their migration route through the embryo during the early stages of embryogenesis. PGCs also undergo global chromatin remodeling, including the erasure and reestablishment of genomic imprints, during this migration. While PGCs do not spontaneously form teratomas, their malignant development into germ cell tumors (GCTs) in vivo is often accompanied by the retention of hypomethylation at the IGF2-H19 imprinting control differentially methylated region (DMR). Previous studies in bimaternal embryos determined that proper genomic imprinting at two paternally imprinted loci was necessary for their growth and development: Igf2-H19 and …

Eye Repair In Xenopus Laevis, Cindy Xuan-Mai Kha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Eye development in vertebrates of complex steps that include specific interactions of the neuroectoderm and overlying head ectoderm. The African clawed frog, Xenopus laevis (X. laevis), has a well-characterize eye developmental pathway and is an established model for eye regeneration research. Additionally, Xenopus frogs have high regenerative abilities to regenerate individual eye tissues such as the retina, lens, and cornea. However, it was previously shown that the removal of the specified eye field during the neurulation stage or an eye during the swimming tadpole stage does not permit an eye to regenerate. Here we will describe a model for investigating …

Abnormal Dendritic Maturation Of Developing Cortical Neurons Exposed To Corticotropin Releasing Hormone (Crh): Insights Into Effects Of Prenatal Adversity?, Megan M. Curran, Curt A. Sandman, Elysia Poggi Davis, Laura M. Glynn, Tallie Z. Baram

Psychology: Faculty Scholarship

Corticotropin releasing hormone (CRH) produced by the hypothalamus initiates the hypothalamic-pituitary-adrenal (HPA) axis, which regulates the body’s stress response. CRH levels typically are undetectable in human plasma, but during pregnancy the primate placenta synthesizes and releases large amounts of CRH into both maternal and fetal circulations. Notably, placental CRH synthesis increases in response to maternal stress signals. There is evidence that human fetal exposure to high concentrations of placental CRH is associated with behavioral consequences during infancy and into childhood, however the direct effects on of the peptide on the human brain are unknown. In this study, we used a …

Macrophages Are Necessary For Epimorphic Regeneration In African Spiny Mice, Jennifer Simkin, Thomas R. Gawriluk, John C. Gensel, Ashley W. Seifert

Biology Faculty Publications

How the immune system affects tissue regeneration is not well understood. In this study, we used an emerging mammalian model of epimorphic regeneration, the African spiny mouse, to examine cell-based inflammation and tested the hypothesis that macrophages are necessary for regeneration. By directly comparing inflammatory cell activation in a 4 mm ear injury during regeneration (Acomys cahirinus) and scarring (Mus musculus), we found that both species exhibited an acute inflammatory response, with scarring characterized by stronger myeloperoxidase activity. In contrast, ROS production was stronger and more persistent during regeneration. By depleting macrophages during injury, we demonstrate …

Lymphoid Hematopoiesis And The Role Of B-Cells In Transgenic Mouse Model Of Sickle Cell Disease, Christina Cotte

University Scholar Projects

Sickle cell disease (SCD) has been shown to be associated with decreased baseline immunity and thus increased susceptibility to infection. I sought to discern possible causes of this by looking into the correlations between SCD and hematopoiesis, the immune system and the neuroendocrine system, and ultimately by conducting experiments surrounding the impaired immune system of SCD. These experiments focused on the potential causes and effects of the diminution of B-1a cells in the SCD spleen. Adoptive transfers, infections with Streptococcus pneumoniae, and histologic imaging were conducted to establish if the diminution of the B-1a cells in the SCD spleen …

Bioethics In The Work Of Ernest Everett Just: + Missing - Some 400 Pages, Theodore Walker

Perkins Faculty Research and Special Events

Biology + ethics = bioethics. Here we see that Howard University biologist Ernest Everett Just (born 1883, died 1941) connected biology to ethics.

According to Just, various forms of specific biology (including especially cell biology) plus “general biology” are necessary for explaining adequately the origin of ethical behaviors. Social ethical behaviors, especially mutual aid and cooperative interactions with others and the environment, are essential to evolutionary advances among living creatures, ranging from humans to cells. Accordingly, theory of ethics (moral theory) should have roots in biology.

Also, Just wrote an unpublished book-length manuscript—“some 400 typed pages” (Just 1940)—on seeking the …

Mammary Extracellular Matrix Directs Differentiation Of Testicular And Embryonic Stem Cells To Form Functional Mammary Glands In Vivo, Robert D. Bruno, Jodie M. Fleming, Andrea L. George, Corinne A. Boulanger, Pepper Schedin, Gilbert H. Smith

School of Medical Diagnostics & Translational Sciences Publications

Previously, we demonstrated the ability of the normal mammary microenvironment (niche) to direct non-mammary cells including testicular and embryonic stem cells (ESCs) to adopt a mammary epithelial cell (MEC) fate. These studies relied upon the interaction of transplanted normal MECs with non-mammary cells within the mammary fat-pads of recipient mice that had their endogenous epithelium removed. Here, we tested whether acellular mammary extracellular matrix (mECM) preparations are sufficient to direct differentiation of testicular-derived cells and ESCs to form functional mammary epithelial trees in vivo. We found that mECMs isolated from adult mice and rats were sufficient to redirect testicular derived …

Sirt1 Regulates Glial Progenitor Proliferation And Regeneration In White Matter After Neonatal Brain Injury., Beata Jablonska, Marcin Gierdalski, Li-Jin Chew, Teresa Hawley, Mackenzie Catron, Arturo Lichauco, Juan Cabrera-Luque, Tracy Yuen, David Rowitch, Vittorio Gallo

Pediatrics Faculty Publications

Regenerative processes in brain pathologies require the production of distinct neural cell populations from endogenous progenitor cells. We have previously demonstrated that oligodendrocyte progenitor cell (OPC) proliferation is crucial for oligodendrocyte (OL) regeneration in a mouse model of neonatal hypoxia (HX) that reproduces diffuse white matter injury (DWMI) of premature infants. Here we identify the histone deacetylase Sirt1 as a Cdk2 regulator in OPC proliferation and response to HX. HX enhances Sirt1 and Sirt1/Cdk2 complex formation through HIF1α activation. Sirt1 deacetylates retinoblastoma (Rb) in the Rb/E2F1 complex, leading to dissociation of E2F1 and enhanced OPC proliferation. Sirt1 knockdown in culture …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

Microrna-Target Interactions In Embryonic Stem Cells, Shuang Wu

Graduate School of Biomedical Sciences Theses and Dissertations

Animal embryogenesis is a highly orchestrated process involving many geneexpression programs that determine specific fates of individual cells during development. Gene expression can be regulated at different stages such as at transcription initiation or mRNA stability, and microRNA-mediated gene regulation is a crucial pathway on the regulation of mRNA stability. microRNAs, or miRNAs, are small, conserved non-coding RNAs that negatively regulate gene expression post-transcriptionally. The mouse miR-290-295 cluster and its human homolog miR-371-373 are stem cell-specific miRNA clusters, and their expression can only be observed in early embryos, primordial germ cells, germ cell compartments of adult testis and embryonic stem …

Genetic Analysis Reveals A Hierarchy Of Interactions Between Polycystin-Encoding Genes And Genes Controlling Cilia Function During Left-Right Determination, Daniel T. Grimes, Jennifer L. Keynton, Maria T. Buenavista, Xingjian Jin, Saloni H. Patel, Shinohara Kyosuke, Jennifer Vibert, Debbie J. Williams, Hiroshi Hamada, Rohana Hussain, Surya M. Nauli, Dominic P. Norris

Pharmacy Faculty Articles and Research

During mammalian development, left-right (L-R) asymmetry is established by a cilia-driven leftward fluid flow within a midline embryonic cavity called the node. This ‘nodal flow’ is detected by peripherally-located crown cells that each assemble a primary cilium which contain the putative Ca²⁺ channel PKD2. The interaction of flow and crown cell cilia promotes left side-specific expression of Nodal in the lateral plate mesoderm (LPM). Whilst the PKD2-interacting protein PKD1L1 has also been implicated in L-R patterning, the underlying mechanism by which flow is detected and the genetic relationship between Polycystin function and asymmetric gene expression remains unknown. Here, we …

Programming Heart Disease: Does Poor Maternal Nutrition Alter Expression Of Cardiac Markers Of Proliferation, Hypertrophy, And Fibrosis In Offspring?, Cathy Chun

Honors Scholar Theses

Maternal malnutrition can affect fetal organogenesis, metabolic processes, and factors involved in developmental regulation. Of the many physiological effects poor maternal nutrition can induce in offspring, one of the most important organs affected is the heart. Cardiovascular disease has been associated with poor maternal diet. It also been suggested that hypertension can originate during impaired intrauterine growth and development. Hypertension can trigger hypertensive heart disease and is associated with numerous heart complications. We hypothesized that poor maternal nutrition would alter critical growth factors associated with normal heart development, specifically, insulin-like growth factor (IGF)-1, IGF-2, transforming growth factor (TGF)β, and connective …

K14+ Compound Niches Are Present On The Mouse Cornea Early After Birth And Expand After Debridement Wounds., Ahdeah Pajoohesh-Ganji, Sonali Pal-Ghosh, Gauri Tadvalkar, Mary Ann Stepp

Anatomy and Regenerative Biology Faculty Publications

Background: We previously identified compound niches (CNs) at the limbal:corneal border of the mouse cornea that contain corneal epithelial progenitor cells, express Keratin 8 (K8), and goblet cell mucin Muc5AC. During re-epithelialization after 2.5 mm epithelial debridement wounds, CNs migrate onto the cornea and expand in number mimicking conjunctivalization. When CNs form during development and whether they express corneal epithelial progenitor cell enriched K14 was not known.

Results: To provide insight into corneal epithelial homeostasis, we quantify changes in expression of simple (K8, K18, K19) and stratified squamous epithelial keratins (K5, K12, K14, and K15) during postnatal development and in …

Functional Analysis Of Rpl22: Coordinating Differentiation Signals And Developmental Gene Translation To Promote Cell Fate Decisions, Stephen Kim

Graduate School of Biomedical Sciences Theses and Dissertations

The execution of meiosis and spore formation in S. cerevisiae requires a transient transcription program that is initiated by Ime I-dependent destruction of the repressor Ume6. IMEJ transcription is tightly contro1led by both cell type and nutritional cues but how its translation is regulated has been unknown. This study demonstrates that Rpl22A and Rpl22B, eukaryotic-specific ribosomal protein paralogs of the 60S large subunit, are required for efficient Ime I translation. While IME1 mRNA is induced normally in the absence of both para logs following transfer to sporulation medium, Ume6 remains stabilized, downstream early meiotic gene remain repressed, and development is …

Homocysteine And Csrp-3 Protein In Migrating Neural Crest Cells: A Quantitative And Qualitative Confocal Microscopy Study, Allysan R. White

Dissertations and Theses @ UNI

Congenital heart defects are one of the leading causes of infant death. High maternal blood serum levels of the amino acid homocysteine and the frequency of heart defects are correlated, but the immediate cause is unknown. During early embryonic development, a distinctive population of cells arises dorsally as the neural tube closes, forming the brain and spinal cord. These are the neural crest cells, which play a crucial role in the development of the nervous system, head skeletal, certain endocrine and connective tissues, and, notably, the heart’s outflow region. These migratory cells will follow specific pathways and respond to signals …

Dna Repair Deficiency In Huntington's Disease Fibroblasts And Induced Pluripotent Stem Cells, Peter Anthony Mollica

Biological Sciences Theses & Dissertations

Mutant huntingtin protein (mhtt)– the protein responsible for cellular dysfunction in Huntington’s disease (HD) –is a product of an expanded trinucleotide repeat (TNR) cytosine-adenine-guanine (CAG) sequence in exon 1 of the huntingtin (HTT) gene. The pathology of HD has been extensively researched; however, the mechanism by which the disease-causing TNR expansions occur in somatic cells remains elusive. Interestingly, HD has often been referred to a ‘DNA repair disease’, even though DNA repair dysfunction in situ has not been identified. We hypothesized that presence of the mhtt protein affects the expression of DNA repair genes used to address DNA repair, ultimately …

Functional Characterization Of The Roles Of Endocytic Recycling Regulator Ehd1 Using In Vivo And In Vitro Analyses, Priyanka Arya

Theses & Dissertations

Endocytic recycling is a fundamental cellular process that allows the precise regulation of the membrane components and receptors at the cell surface. Recent studies have established that the C-terminal Eps15 homology domain-containing (EHD) proteins function as key regulators of this process. Four highly-conserved members of the EHD protein family in mammals, EHD1-EHD4, play shared as well as unique roles in endocytic trafficking. Studies presented here demonstrate a critical role of EHD1 in the normal ocular development in mice. Ehd1 knockout mice generated in our laboratory displayed gross ocular phenotypes including the anophthalmia, microphthalmia, and congenital cataracts. Hematoxylin and eosin (H&E) …

Viewing The Extracellular Matrix: An Imaging Method For Tissue Engineering, Michael Drakopoulos, Sarah Calve

The Summer Undergraduate Research Fellowship (SURF) Symposium

The field of regenerative medicine seeks to create replacement tissues and organs, both to repair deficiencies in biological function and to treat structural damage caused by injury. Scaffoldings mimicking extracellular matrix (ECM), the structure to which cells attach to form tissues, have been developed from synthetic polymers and also been prepared by decellularizing adult tissue. However, the structure of ECM undergoes significant remodeling during natural tissue repair, suggesting that ECM-replacement constructs that mirror developing tissues may promote better regeneration than those modeled on adult tissues. This work investigated the effectiveness of a method of viewing the extracellular matrix of developing …

Detection Of Ubiquitination On Syk And Documenting Syk Stability, Izabela Mazur, Wen Horng Wang, Robert J. Geahlen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Post-translational modifications regulate the activities of proteins important to numerous diseases. Spleen Tyrosine Kinase (Syk) is particularly interesting to researchers because it modifies many targets and plays multiple roles in regulating cells in our bodies and its abnormal modifications may contribute to cancer, Alzheimer’s disease and allergies. In an attempt to study these modifications of Syk, we first looked at detecting ubiquitination on Syk protein. Ubiquitin, a small 8 kDa molecule, attaches to lysine residues on protein. The attachment of ubiquitin to Syk may cause Syk to either propagate signals onwards to activate other proteins or signal it to undergo …

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 …

The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne

Honors Scholar Theses

Muscle growth in young horses is characterized by an increase in muscle cross-sectional area, which can be accomplished through the activation and differentiation of satellite cells. Satellite cells can be stimulated or inhibited in response to different cytokines and growth factors and are key mediators of muscle hypertrophy and regeneration. The aim of this study was to investigate the growth of the longissimus dorsi (LD) muscle in horses under 5 years of age and to obtain preliminary data on satellite cell behavior in foals. The area, width, height, and subcutaneous fat were measured using ultrasonography at 6-month increments over the …

The Effects Of Propofol, Sodium Pentobarbital, And Ketamine Hydrochloride On In Vitro Mouse Embryonic Development, Tyler C. Balak

Theses and Dissertations in Biomedical Sciences

Every year more than 75,000 pregnant women are exposed to teratogenic medications or general anesthesia during non-obstetric surgery in the US,1-4 and embryonic effects of general anesthesia are of particular interest in laboratory research and veterinary medicine. The mouse system is used to screen potential toxic effects of anesthetics used in egg retrieval for in vitro fertilization (IVF), or those of pharmacologic agents which may come in contact with the egg or early embryo. Mouse preimplantation 2-cell embryos were exposed in vitro to incremental concentrations of common general anesthetics within and exceeding the normal clinical dosage range for mice (propofol …

The Use Of Stem Cells In Burn Wound Healing: A Review, Fadi Ghieh, Rosalyn A. Jurjus, Amir Ibrahim, Alice Gerges Geagea, Hisham Daouk, Bassel El Baba, Sana Cham, Michel Matar, Wadih Zein, Abdo Jurjus

Anatomy and Regenerative Biology Faculty Publications

Burn wound healing involves a series of complex processes which are subject to intensive investigations to improve the outcomes, in particular, the healing time and the quality of the scar. Burn injuries, especially severe ones, are proving to have devastating effects on the affected patients. Stem cells have been recently applied in the field to promote superior healing of the wounds. Not only have stem cells been shown to promote better and faster healing of the burn wounds, but also they have decreased the inflammation levels with less scar progression and fibrosis. This review aims to highlight the beneficial therapeutic …

Once Upon A Microscopic Slide: The Story Of Histology, Inaya Hussein, Mohamad Raad, Rawan Safa, Rosalyn A. Jurjus, Abdo Jurjus

Anatomy and Regenerative Biology Faculty Publications

For centuries, histology has maintained its remarkable place in the medical curriculum. However, its teaching has been influenced by the new technological advancement that has reshaped medicine teaching into a more modern student-friendly form. Since its inception in the 18th century, the discipline of histology has progressed hand in hand with the advancements in microscopy and microscopic technologies, including immunohistochemistry. In the traditional curriculum of USA medical schools, especially after the first Flexner’s report of 1910, histology was considered as very essential topic for a physician studying the “Art and Science” of medicine. In this era, the teaching relied more …

Rab8 Directs Tubulation And Furrow Ingression During Epithelial Formation In Drosophila Melanogaster, Lauren Mackenzie Mavor

Electronic Theses and Dissertations

One of the most fundamental changes in cell morphology is the formation of a plasma membrane furrow. The Drosophila embryo undergoes several cycles of rapid furrow ingression during early development, which culminates in the formation of an epithelial sheet. Previous studies have demonstrated the requirement for intracellular trafficking pathways in furrow ingression; however, the pathways that link compartmental behaviors with cortical furrow ingression events have remained unclear. This research shows that Rab8, a small GTPase associated with late exocytic trafficking events, demonstrates striking dynamic behaviors in vivo; transitioning from punctate structures to a stable association with the cortex during …

Pcdh19 Expression In Normal And Regenerating Adult Zebrafish Retinas, Kristin N. Forkapa Ms.

Williams Honors College, Honors Research Projects

My Honors Research Project will test the function of the N-cadherin molecule on the zebrafish optic nerve regeneration. N-cadherin is a member of the cadherin superfamily. Cadherins are cell adhesion molecules important for animal development and maintenance of adult structures. Unlike mammals, fish and amphibians have the ability to regenerate their optic nerve after damages. Molecular mechanisms underlying the optic nerve regeneration are still under intense investigation. Studies in Dr. Liu’s laboratory showed that expression of several cadherins, including N-cadherin, was greatly increased during adult zebrafish optic nerve regeneration, suggesting that cadherins may be involved in the optic nerve regeneration …

Effects Of Proline And Glycine On The Cnidocyte Discharge Of Hydra Magnipapillata, Janine R. Appleton

Honors Theses and Capstones

The sense of taste enables animals to utilize environmental cues to detect favorable foods. Through specialized sensory receptors, Cnidarians employ stinging cells called cnidocytes to perform a variety of activities such as locomotion, capturing prey, inducing of feeding responses, and defense. Their discharge is highly regulated by mechanical and chemical signals that are mediated by a complex system including the opsin and taste pathways. Taste 1 Receptors (T1R) have previously been isolated in vertebrates but only until recently, have been noted in invertebrates. Receptors specific to L- amino acids corresponding to the taste sensation of umami, were studied to determine …

Myoepithelial Cell Morphogenesis And Differentiation In The Mouse Submandibular Salivary Gland In Development And Disease, Elise Marie Gervais

Legacy Theses & Dissertations (2009 - 2024)

Organogenesis is the process by which tissues organize, gain considerable size, and undergo cellular differentiation or specialization to form fully functional organs. To study the processes involved in organogenesis of branched organs, the mouse submandibular salivary gland is frequently used as a model system, as it can undergo morphogenesis and differentiation and be genetically manipulated ex vivo. The mouse submandibular salivary gland undergoes a specific process of outgrowth and invagination known as branching morphogenesis which allows for the significant increase in gland size and complexity, as well as maximization of surface area for secretion of saliva. Surrounding the mouse submandibular …

Vitamin D Signaling And The Impact On Mouse Mammary Gland Epithelium, Donald Grant Matthews

Legacy Theses & Dissertations (2009 - 2024)

A strong correlation between vitamin D deficiency and increased breast cancer incidence and mortality has been well established, leading researchers to further examine the possibility of using vitamin D in treatment and prevention strategies. Our long term goal is to elucidate the mechanisms by which vitamin D pathway signaling impacts on breast cancer. Generation of the high-affinity vitamin D receptor (VDR) ligand 1,25-dihydroxyvitamin D (1,25-D) from 25-hydroxyvitamin D (25-D) is mediated by CYP27B1 which is present and developmentally regulated in multiple tissues including the mammary gland. We utilized transgenic mouse models combined with diet-induced vitamin D deficiency to determine whether …

Using A Novel Multiplexing Method To Track Cell Populations And Cytodifferentiation During Development Of The Submandibular Salivary Gland, Charles Thomas Manhardt

Legacy Theses & Dissertations (2009 - 2024)

The development of submandibular salivary glands is complex and requires coordination of specific signaling events. Submandibular salivary glands originate as an epithelial invagination into the adjacent mesenchyme that leads to a single stalk and end bud; this end bud will go through a clefting process. Numerous rounds of clefting will lead to a fully developed salivary gland by this process, which is known as branching morphogenesis. As the gland undergoes morphogenesis, specific cues leading to differentiation of multiple cell types and even epithelial sub classes are required. By the later stages of development the glands are fully innervated, have an …