Cell and Developmental Biology Commons^™

The Neurobiology Of Circadian Rhythms, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Daily rhythms in nature, such as the opening and closing of flowers or our patterns of sleep and wakefulness and their association with the perpetual alteration of night and day, were recognized in antiquity although their origins were not questioned until the eighteenth century. The French Astronomer Jean-Jacques d’Ortous de Mairan conducted an investigation into whether the leaves of the Mimosa plant opened in response to light.¹ While de Mairan’s experiments were the first to question the origin of such daily rhythms, Augustin Pyramus de Candolle is credited with the first suggestion that they arose through an internal timekeeping …

The Ras Effector Nore1a Forms A Tumor Suppressor Complex With Brca1., Nicholas C Nelson

Electronic Theses and Dissertations

Ras proteins function as molecular signaling switches that can stimulate multiple mitogenic pathways in response to extracellular signaling. Oncogenic activation of Ras by structural mutation is a highly transforming event in ~1/3 of human cancers. However, aberrant Ras activation can also promote oncogene-induced senescence. This Ras-induced irreversible growth arrest is a physiological process that acts as a barrier to malignancy. The mechanisms by which Ras drives senescence and how this process is bypassed during Ras-driven transformation remains poorly understood.

Although mutations in the RAS gene are extremely rare in human breast cancer, the Ras signaling pathway is constitutively activated in …

Problem Solving Skill And Obesity In Children, Caitlin R. Spano

The Eleanor Mann School of Nursing Undergraduate Honors Theses

Abstract:

Introduction: Childhood obesity is a problem that leads to many serious health effects including early maturation, decreased quality of life and increased risk for cardiovascular disease. In 2012, over one third of children were considered obese (Childhood Obesity Facts 2015). Efforts have been made to reduce this number but they have not been fully successful (Nutrition Standards for School Meals 2015, Prevalence of Childhood obesity in the United States 2011-2012 2015). What other factors are causing kids to choose foods that lead to weight gain.

Literature Review: In research regarding psychological motivations of overeating, there has been a correlation …

Response Of Bacterial Cells To Fluctuating Environment, Sudip Nepal

Graduate Theses and Dissertations

We have studied morphological and genomic variations occurring in a mesophilic bacterium Escherichia coli (E. coli) in a wide range of continuous and fluctuating hydrostatic pressures. For all the studies here the temperature is maintained at 37◦C, the optimal growth tem- perature of E. coli at atmospheric pressure. Cell division is inhibited at high hydrostatic pressures resulting in an increase of cell length. The increase of cell-length depends on the extent and duration of the stress applied on bacterial cells. We have studied the effect of high pressure stress in three different conditions – (i) Wild-type cells (almost no genetic …

Compounds Released From Biomass Deconstruction: Understanding Their Effect On Cellulose Enzyme Hydrolysis And Their Biological Activity, Angele Djioleu

Graduate Theses and Dissertations

The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in …

Eicosapentaenoic Acid (Epa) From Porphyridium Cruentum: Increasing Growth And Productivity Of The Microalgae For Pharmaceutical Products, Maryam Asgharpour

Graduate Theses and Dissertations

One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate …

Leptin Regulates The Expression Of Autophagy-Related Genes In Chickens, Peter Olawale Ishola

Graduate Theses and Dissertations

Autophagy or cellular self-digestion, a lysosomal degradation pathway that is conserved from yeast to human, plays a key role in recycling cellular constituents, including damaged organelles. It also plays a pivotal role in the adaptation of cells to a plethora of distinct stressors including starvation. Autophagy has been extensively studied in mammals and yeast, but little is known in avian species. Thus, the major objective of the present study was to determine the effects of leptin on autophagy-related genes in chicken hypothalamus, muscle and liver. Leptin is an adipocytokine that is mostly produced by white adipose cells in mammals (as …

Dancing Through Life: Molecular Dynamics Simulations And Network-Centric Modeling Of Allosteric Mechanisms In Hsp70 And Hsp110 Chaperone Proteins, Gabrielle Stetz, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hsp70 and Hsp110 chaperones play an important role in regulating cellular processes that involve protein folding and stabilization, which are essential for the integrity of signaling networks. Although many aspects of allosteric regulatory mechanisms in Hsp70 and Hsp110 chaperones have been extensively studied and significantly advanced in recent experimental studies, the atomistic picture of signal propagation and energetics of dynamics-based communication still remain unresolved. In this work, we have combined molecular dynamics simulations and protein stability analysis of the chaperone structures with the network modeling of residue interaction networks to characterize molecular determinants of allosteric mechanisms. We have shown that …

Endothelin-B Receptor Activation In Astrocytes Regulates The Rate Of Oligodendrocyte Regeneration During Remyelination., Timothy R. Hammond, Brian Mcellin, Paul D Morton, Matthew Raymond, Jeff Dupree, Vittorio Gallo

Medicine Faculty Publications

Reactive astrogliosis is an essential and ubiquitous response to CNS injury, but in some cases, aberrant activation of astrocytes and their release of inhibitory signaling molecules can impair endogenous neural repair processes. Our lab previously identified a secreted intercellular signaling molecule, called endothelin-1 (ET-1), which is expressed at high levels by reactive astrocytes in multiple sclerosis (MS) lesions and limits repair by delaying oligodendrocyte progenitor cell (OPC) maturation. However, as ET receptors are widely expressed on neural cells, the cell- and receptor-specific mechanisms of OPC inhibition by ET-1 action remain undefined. Using pharmacological approaches and cell-specific endothelin receptor (EDNR) ablation, …

Hepatic Nutrient And Hormonal Regulation Of The Pancreatic-Derived Factor (Pander) Promoter, Whitney Ratliff

USF Tampa Graduate Theses and Dissertations

PANcreatic-DERived factor (PANDER, FAM3B) has been shown to regulate glycemic levels via interactions with both pancreatic islets and the liver. Although PANDER is predominantly expressed from the endocrine pancreas, recent work has provided sufficient evidence that the liver may also be an additional tissue source of PANDER production. At physiological levels, PANDER is capable of disrupting insulin signaling and promoting increased hepatic glucose production. As shown in some animal models, strong expression of PANDER, induced by viral delivery within the liver, induces hepatic steatosis. However, no studies to date have explicitly characterized the transcriptional regulation of PANDER from the liver. …

The Transient Receptor Potential Melastatin 2 (Trpm2) Channel Contributes To Beta-Amyloid Oligomer-Related Neurotoxicity And Memory Impairment, Valeriy G. Ostapchenko, Megan Chen, Monica S. Guzman, Yu-Feng Xie, Natalie Lavine, Jue Fan, Flavio H. Beraldo, Amanda C. Martyn, Jillian C. Belrose, Yasuo Mori, John F. Macdonald, Vania F. Prado, Marco A. M. Prado, Michael F. Jackson

Anatomy and Cell Biology Publications

In Alzheimer's disease, accumulation of soluble oligomers of beta-amyloid peptide is known to be highly toxic, causing disturbances in synaptic activity and neuronal death. Multiple studies relate these effects to increased oxidative stress and aberrant activity of calcium-permeable cation channels leading to calcium imbalance. The transient receptor potential melastatin 2 (TRPM2) channel, a Ca2+-permeable nonselective cation channel activated by oxidative stress, has been implicated in neurodegenerative diseases, and more recently in amyloid-induced toxicity. Here we show that the function of TRPM2 is augmented by treatment of cultured neurons with beta-amyloid oligomers. Aged APP/PS1 Alzheimer's mouse model showed increased levels of …

Age-Associated Methylation Suppresses Spry1, Leading To A Failure Of Re-Quiescence And Loss Of The Reserve Stem Cell Pool In Elderly Muscle., Anne Bigot, William J Duddy, Zamalou G Ouandaogo, Elisa Negroni, Virginie Mariot, Svetlana Ghimbovschi, Brennan Harmon, Aurore Wielgosik, Camille Loiseau, Joseph Devaney, Julie Dumonceaux, Gillian Butler-Browne, Vincent Mouly, Stéphanie Duguez

Genomics and Precision Medicine Faculty Publications

The molecular mechanisms by which aging affects stem cell number and function are poorly understood. Murine data have implicated cellular senescence in the loss of muscle stem cells with aging. Here, using human cells and by carrying out experiments within a strictly pre-senescent division count, we demonstrate an impaired capacity for stem cell self-renewal in elderly muscle. We link aging to an increased methylation of the SPRY1 gene, a known regulator of muscle stem cell quiescence. Replenishment of the reserve cell pool was modulated experimentally by demethylation or siRNA knockdown of SPRY1. We propose that suppression of SPRY1 by age-associated …

Stochastic Models For Plant Microtubule Self-Organization And Structure, Ezgi Can Eren, Ram Dixit, Natarajan Gautam

Biology Faculty Research

One of the key enablers of shape and growth in plant cells is the cortical microtubule (CMT) system, which is a polymer array that forms an appropriately-structured scaffolding in each cell. Plant biologists have shown that stochastic dynamics and simple rules of interactions between CMTs can lead to a coaligned CMT array structure. However, the mechanisms and conditions that cause CMT arrays to become organized are not well understood. It is prohibitively time-consuming to use actual plants to study the effect of various genetic mutations and environmental conditions on CMT self-organization. In fact, even computer simulations with multiple replications are …

Chemical-Free Technique To Study The Ultrastructure Of Primary Cilium, Ashraf M. Mohieldin, Wissam A. Aboualaiwi, Min Gao, Surya M. Nauli

Pharmacy Faculty Articles and Research

A primary cilium is a hair-like structure with a width of approximately 200 nm. Over the past few decades, the main challenge in the study of the ultrastructure of cilia has been the high sensitivity of cilia to chemical fixation, which is required for many imaging techniques. In this report, we demonstrate a combined high-pressure freezing (HPF) and freeze-fracture transmission electron microscopy (FFTEM) technique to examine the ultrastructure of a cilium. Our objective is to develop an optimal high-resolution imaging approach that preserves cilia structures in their best natural form without alteration of cilia morphology by chemical fixation interference. Our …

Hyperactivity And Attention Deficits In Mice With Decreased Levels Of Stress-Inducible Phosphoprotein 1 (Stip1), Flavio H. Beraldo, Anu Thomas, Benjamin Kolisnyk, Pedro H. Hirata, Xavier De Jaeger, Amanda C. Martyn, Jue Fan, Daniela F. Goncalves, Matthew F. Cowan, Talal Masood, Vilma R.. Martins, Robert Gros, Vania F. Prado, Marco A. M. Prado

Anatomy and Cell Biology Publications

Stress-inducible phosphoprotein I (STIP1, STI1 or HOP) is a cochaperone intermediating Hsp70/Hsp90 exchange of client proteins, but it can also be secreted to trigger prion protein-mediated neuronal signaling. Some mothers of children with autism spectrum disorders (ASD) present antibodies against certain brain proteins, including antibodies against STIP1. Maternal antibodies can cross the fetus blood-brain barrier during pregnancy, suggesting the possibility that they can interfere with STIP1 levels and, presumably, functions. However, it is currently unknown whether abnormal levels of STIP1 have any impact in ASD-related behavior. Here, we used mice with reduced (50%) or increased STIP1 levels (fivefold) to test …

The Anatomy Of Porcine And Human Larynges: Structural Analysis And High Resolution Magnetic Resonance Imaging Of The Recurrent Laryngeal Nerve, Nena Lundgreen Mason

Theses and Dissertations

The recurrent laryngeal nerve (RLN) innervates all the intrinsic muscles of the larynx that are responsible for human vocalization and language. The RLN runs along the tracheoesophageal groove bilaterally and is often accidentally damaged or transected during head and neck surgical procedures. RLN palsy and vocal cord paralysis are the most common and serious post op complications of thyroid surgeries. Patients who suffer from RLN injury can develop unilateral or bilateral vocal fold paralysis (BVFP). Theoretically, selective reinnervation of the posterior cricoarytenoid muscle would be the best treatment for BVFP. The phrenic nerve has been shown in several studies to …

Migration In The Social Stage Of Dictyostelium Discoideum Amoebae Impacts Competition, Chandra N. Jack, Neil J. Buttery, Boahemaa Adu-Oppong, Michael Powers, Christopher R.L. Thompson, David Queller, Joan E. Strassmann

Biology Faculty Research

Interaction conditions can change the balance of cooperation and conflict in multicellular groups. After aggregating together, cells of the social amoeba Dictyostelium discoideum may migrate as a group (known as a slug) to a new location. We consider this migration stage as an arena for social competition and conflict because the cells in the slug may not be from a genetically homogeneous population. In this study, we examined the interplay of two seemingly diametric actions, the solitary action of kin recognition and the collective action of slug migration in D. discoideum, to more fully understand the effects of social competition …

The Generation, Exploitation And Future Of Induced Pluripotent Stem Cells, Jacob Steenwyk

Scholarly Undergraduate Research Journal at Clark (SURJ)

The foundational advancements of John Gurdon and Shinya Yamanaka have improved understanding of dedifferen- tiation of cells to a pluripotent state. The seminal discovery established a novel system to study disease pathogenesis, drug screening, and toxicity, as well as sprouted the new field of regenerative medicine. In this article, the method- ology to obtain dedifferentiated cells, known as induced pluripotent stem (iPS) cells, subsequent validation, and application of which are reviewed. The experiments investigated here aim to demonstrate the capacity of iPS cells to replace the ethically-gray human embryonic cells by developing human livers and viable, healthy animals. It is …

Dynamic Ubiquitination Drives Herpesvirus Neuroinvasion, Nicholas J. Huffmaster, Patricia J. Sollars, Alexsia L. Richards, Gary E. Pickard, Gregory A. Smith

School of Veterinary and Biomedical Sciences: Faculty Publications

Neuroinvasive herpesviruses display a remarkable propensity to enter the nervous system of healthy individuals in the absence of obvious trauma at the site of inoculation. We document a repurposing of cellular ubiquitin during infection to switch the virus between two invasive states. The states act sequentially to defeat consecutive host barriers of the peripheral nervous system and together promote the potent neuroinvasive phenotype. The first state directs virus access to nerve endings in peripheral tissue, whereas the second delivers virus particles within nerve fibers to the neural ganglia. Mutant viruses locked in either state remain competent to overcome the corresponding …

Characterization And Diurnal Measurement Of Oral Inflammation In Association With Glycemic Control, Periodontal Status, & Glucose Stimulation, Melanie N. Kuehl

USF Tampa Graduate Theses and Dissertations

Diabetes has afflicted 8.3%, approximately 25.8 million, of the United States population and is the seventh leading cause of death [1]. Type I diabetes (T1D) accounts for 5 to 10% of all diagnosed cases of diabetes in the United States [2]. If present trends continue, the rate of T1D incidence among children under the age of 14 will increase by 3% globally [3]. T1D is an autoimmune disorder in which the β-cells of the pancreatic islets are destroyed, leading to high blood sugar. Hyperglycemia and loss of immunological tolerance to self-antigens are common associations of T1D [4]. Periodontal disease impacts …