Cell and Developmental Biology Commons^™

Encapsulation And Culture Of Plant Protoplasts In Hydrogel Microspheres Using Droplet Microfluidics, Matthew Grasso

Graduate College Dissertations and Theses

Plant morphogenesis requires the coordinated growth between cells and their neighbors. This coordination is regulated by internal and external signals that are both physical and chemical. It is understood that both mechanical and molecular signals are involved in the regulation of plant morphogenesis however, how mechanical signals induce molecular signals and vice versa is not. This is due to a lack of research tools for manipulating and measuring the mechanical environment of growing plant cells. Such tools would ideally provide individual plant cells with mechanically tunable physical microenvironments. This may allow changes in the cells physical environment to be linked …

Spatial And Temporal Control Of The Kinesin Motors Kif11 And Kif22 In Mitosis, Alex Frances Thompson

Graduate College Dissertations and Theses

Mitosis requires the control of mechanical forces generated by kinesin motors to ensure equal segregation of chromosomes into two daughter cells. Two kinesins contributing to these forces are KIF11 (or Eg5), which crosslinks and slides anti-parallel microtubules, and KIF22 (or Kid), which binds to microtubules and chromosome arms. This work addresses how post-translational modifications and pathogenic mutations alter the structure and function of KIF11 and KIF22.

The homotetrameric kinesin KIF11 is subject to acetylation at lysine 146, a residue in the a2 helix of the motor domain. The effect of this acetylation was assessed at the single molecule and cellular …

Mitochondrial Dynamics Regulation Of The Lung Epithelial Response To Complex Allergen, Sierra White

Graduate College Dissertations and Theses

Asthma is a chronic inflammatory disease of the lungs that affects roughly 25 million Americans, costing the United States upwards of $80 billion annually in management and economic loss. The airway epithelium, which serves as the first line of defense against insults in the lung, are now appreciated as key contributors to initiation of this disease. A key regulator of the epithelial response to allergens and other inhaled irritants that can induce an allergic asthmatic response is the mitochondria. During an allergic response, the airway epithelial energy requirement changes, and mitochondrial function is altered, enhancing production of reactive oxygen species, …

The Impact Of Nitric Oxide On Dendritic Cell Metabolism, Julia Priscilla Snyder

Graduate College Dissertations and Theses

Dendritic cells (DCs) are sentinel immune cells capable of directly sensing and responding to pathogens. Upon pathogen recognition, DCs undergo a process of activation that allows them to participate in the proinflammatory response at the site of infection and to initiate the adaptive immune response through antigen presentation to T cells. Because activated DCs serve as the critical link between innate and adaptive immunity, modulating DC activation could be a powerful tool in various clinical contexts such as vaccine design. DC activation is accompanied by widespread changes in metabolism including the rapid upregulation of glycolysis, which is sustained in DCs …

Thyroid Hormone Receptor Beta Inhibits Pi3k Signaling And Glycogen Metabolism In Anaplastic Thyroid Cancer, Cole Davidson

Graduate College Dissertations and Theses

Thyroid cancer is the most common endocrine malignancy, and the global incidence has increased rapidly over the past few decades. While differentiated thyroid cancers often respond to standard therapies, there are no durable long-term treatment options for anaplastic thyroid cancer (ATC). The limited treatment options highlight a need for a deeper understanding of the molecular signaling in these aggressive tumors for development of more effective therapies.Non-steroidal nuclear receptors, such as thyroid hormone receptors (TRs), are an emerging class of therapeutic targets and tumor suppressors in thyroid and other cancers.Loss of expression of the tumor suppressor thyroid hormone receptor beta (TRβ) …

Defining Regional Lung Extracellular Matrix Composition: Implications In Disease And Repair Following Injury, Evan T. Hoffman

Graduate College Dissertations and Theses

Chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) are chronic lung diseases with significant worldwide impact and poor end-stage prognoses. Despite both diseases differing greatly in pathology, both COPD and IPF are hallmarked by drastic alterations to the extracellular matrix (ECM) within distinct anatomical lung regions. These alterations negatively impact cellular regeneration, and subsequently, lung homeostasis, physiology, and repair following injury. Whole decellularized lungs, stripped of cellular material while retaining lung ECM structure and composition, have previously provided complex models for both high-throughput proteomic evaluation of lung ECM as well as ex vivo culture models to study the …

The Maintenance Of Genomic Stability: Impacts Of The Loss Of Kif18a, Leslie Anne Sepaniac

Graduate College Dissertations and Theses

Regulated and repeated cell division is necessary for the development, growth, and reproduction of multicellular organisms. A central purpose of mitosis is to faithfully pass hereditary information from one cell onto two genetically identical daughter cells, thus maintaining genomic stability. Cells employ several mechanisms for maintaining genomic stability, including well-characterized cell cycle checkpoints. However, chromosome segregation errors can occur in spite of these regulatory mechanisms. Such errors can result in an improper number of chromosomes being distributed to daughter cells – termed aneuploidy – or improper localization of chromosomes into separate satellite nuclei – termed micronuclei. What, if any, additional …

The Role Of Peroxiredoxin 4 And Er Redox Stress In Idiopathic Pulmonary Fibrosis, Evan Elko

Graduate College Dissertations and Theses

Idiopathic Pulmonary Fibrosis (IPF) is a disease that is characterized by excessive scar formation in the lung. IPF is a disease associated with aging and is believed to be the manifestation of repeated micro-injuries and lack of adequate repair over time. Notably increases in endoplasmic reticulum (ER) stress of epithelial cells and excessive epithelial cell death have been identified as processes that drive the progression of fibrosis. Every year 34,000 people in the United States are diagnosed with Idiopathic Pulmonary Fibrosis (IPF). The average survival time for these patients is only 3-5 years after diagnosis. Two available drugs stabilize patients …

Investigating The Role Of Protein Kinase A In The Control Of Focal Adhesion And Traction Force Dynamics, Amanda Senatore

Graduate College Dissertations and Theses

Cellular adhesion to the extracellular environment is a critical component of physiological processes and its dysregulation drives pathological processes such as cancer metastasis. The input cells derive from their interaction with the extracellular matrix (ECM) is largely mediated through specialized organelles known as focal adhesions (FAs). FAs tether extracellular matrix-bound integrins to the contractile actin cytoskeleton and serve as attachment points which allow the cell to exert force on the extracellular environment via acto-myosin contractility. In addition to this structural role, FAs function as dynamic signaling hubs that respond to changes in force. Reversible phosphorylation plays a major role in …

A Chemical Genetics Approach To Understand The Regulation Of Cryptosporidium Sexual Differentiation, Md Mahmudul Hasan

Graduate College Dissertations and Theses

Cryptosporidium species are eukaryotic intracellular parasites belonging to the phylum Apicomplexa. C. hominis and C. parvum cause diarrhea in humans which is self-limiting in immunocompetent adults but can have severe consequences in immunocompromised individuals and malnourished children. In developing countries, Cryptosporidium is one of the leading causes of moderate to severe diarrhea in children under five years of age. There is an urgent need for novel therapeutics against this parasite as the current treatment option is inadequate to treat the most vulnerable population to Cryptosporidium infection. Better understandings of the biology of Cryptosporidium would greatly enhance our capability to design …

Regulation Of Neuroinflammation After Ischemic Stroke By Astroglial Endothelin Receptor Type-B Signaling, John Mcinnis

Graduate College Dissertations and Theses

A large body of neuroscientific research has focused on reactive gliosis and glial scar formation because these are among the most prominent features of the cellular response to central nervous system (CNS) injury. Despite much progress in our understanding, controversy remains regarding the relative balance between the protective nature of the astroglial scar and its anti-regenerative features. Recent work suggests that astrocytes are heterogeneous in their resting state and in their reactivity. In traumatic injuries such as stroke and spinal cord injury, proliferative reactive astrocytes protect CNS tissue. By contrast, under neuroinflammatory and/or neurodegenerative conditions, neurotoxic astrocyte phenotypes may contribute …

Anti-Tumor Signaling Of Thyroid Hormone Receptor Beta In Breast And Thyroid Cancer Cells, Eric Bolf

Graduate College Dissertations and Theses

Dysregulation of the tumor suppressor thyroid hormone receptor beta (TRβ) is a frequent event in a number of solid tumors. As a nuclear hormone receptor, the primary function of TRβ is to regulate transcriptional activity in a ligand-dependent manner. However, TRβ activity is not well-defined and the pathways it regulates are not yet fully delineated. The two cancer types where TRβ is best studied are thyroid cancer and breast cancer. Interestingly, thyroid cancer is a risk factor for breast cancer and breast cancer is a risk factor for thyroid cancer, suggestive of an etiological link. Determining the molecular mechanisms of …

Glutathionylation/Glutaredoxin Axis And The Regulation Of Epithelial Cell Plasticity And Fibroblast Activation In Airway Fibrosis, Shi Biao Chia

Graduate College Dissertations and Theses

Asthma is a complex lung disorder that affects more than 200 million people across the globe. About 10% of asthmatics have severe disease accompanied by structural airway remodeling, including subepithelial fibrosis, airway smooth muscle cell hyperplasia, goblet metaplasia, and increased vascularization. Oxidative stress has been well-linked to asthma pathogenesis; however, the precise redox mechanisms governing the pathological states are slowly being teased apart in the recent years. Protein S-glutathionylation (PSSG) is a posttranslational modification where a three amino acid-peptide, glutathione, forms a disulfide bond with reactive cysteines of a protein thereby potentially changing the protein’s biological functions. Glutaredoxins are members …

Pathological Consequences Of Pdi Oxidoreductase Activity On Viral Protein Maturation, Nicolas Chamberlain

Graduate College Dissertations and Theses

The influenza A virus (IAV) causes severe respiratory illness in humans. Current treatments are rapidly becoming ineffective due to the emergence of viral resistance to available therapies such as oseltamivir and zanamivir. Given the impact of this virus there is an urgent need to explore novel targets for new treatments less susceptible to viral mutation; targeting host proteins utilized by the virus may avoid these limitations. It has been shown in vitro that interactions with host ER based protein disulfide isomerases (PDIs) are required for specific IAV proteins to reach their functional conformations. The viral proteins hemagglutinin (HA) and neuraminidase …

Redox Regulation Of Src Kinase: Implications For Innate Il-33 Signaling In Allergen Responses, Christopher Michael Dustin

Graduate College Dissertations and Theses

The proto-oncogene tyrosine kinase Src is a ubiquitously expressed non-receptor tyrosine kinase involved in critical cellular functions including wound healing, migration, survival, and proliferation. Accordingly, aberrant Src signaling is also significantly involved in many diseases. Src is most well known as an oncogenic protein, however, there are emerging roles for Src signaling in various tissues involved in inflammatory diseases. One such tissue is the respiratory epithelium, which comprises the first line of defense against inhaled microbial, particulate, and chemical insults and is a critical nexus of innate immune signaling. Recent work has detailed the involvement of Src in many innate …

Biochemical And Functional Characterization Of Semaphorin6a-Plexina Signaling In Zebrafish Eye Development, Riley St. Clair

Graduate College Dissertations and Theses

During embryonic development, cells respond to extracellular signals to establish proper tissue organization. Semaphorins (Semas) are a large class of secreted and transmembrane proteins that signal through Plexin (Plxn) receptors to guide migrating cells to their correct position and thus play critical roles in the development of various tissues including the nervous and cardiovascular systems. We have previously shown that Sema6A-PlxnA2 signaling is essential for visual system development, as decreasing endogenous Sema6A or PlxnA2 in zebrafish results in decreased cohesion of the early eye field, impaired retinal lamination, and smaller eye size. However, the molecular mechanisms governing these phenotypes are …

Investigation Of Transforming Growth Factor-Alpha And Its Potential Role In Promoting Ovarian Follicular Dominance, Allie Lynn Lundberg

Graduate College Dissertations and Theses

Intraovarian growth factors play a vital role in influencing the fate of ovarian follicles. They affect proliferation versus apoptosis of granulosa cells (GCs), and can influence whether small antral follicles continue their growth or undergo atresia. Transforming Growth Factor-alpha (TGFα), an oocyte-derived growth factor, is thought to regulate granulosa cell function, yet has been largely overshadowed by current interest in TGF-beta superfamily members, such as bone morphogenetic proteins (BMPs) and anti-Mullerian hormone (AMH). In the current study, effects of TGFα on bovine GC proliferation, intracellular signaling and cytokine-induced apoptosis were evaluated. Briefly, all small antral follicles (3-5mm) from bovine ovaries …

Investigating The Role Of Histidyl-Trna Synthetase In Zebrafish Nervous System Development, Ashley Waldron

Graduate College Dissertations and Theses

Histidyl-tRNA Synthetase (HARS) is a member of the family of enzymes that are responsible for attaching specific amino acids to their corresponding tRNA molecules. This function is critical for accurate and efficient protein synthesis and therefore is required in every cell of an organism. Interestingly, there are a growing number of tissue-specific disorders associated with mutations in genes for this family. For example, mutations in HARS have been associated with three different genetic disorders. The tissue most commonly affected in these disorders is nervous tissue and symptoms range from peripheral neuropathy to severe cognitive impairment. The bias towards nervous system …

The Metabotropic Glutamate Receptor Mglur1 Regulates The Voltage-Gated Potassium Channel Kv1.2 Through Agonist-Dependent And Agonist-Independent Mechanisms, Sharath Chandra Madasu

Graduate College Dissertations and Theses

The voltage gated potassium channel Kv1.2 plays a key role in the central nervous system and mutations in Kv1.2 cause neurological disorders such as epilepsies and ataxias. In the cerebellum, regulation of Kv1.2 is coupled to learning and memory. We have previously shown that blocking Kv1.2 by infusing its specific inhibitor tityustoxin-kα (TsTX) into the lobulus simplex of the cerebellum facilitates eyeblink conditioning (EBC) and that EBC itself modulates Kv1.2 surface expression in cerebellar interneurons. The metabotropic glutamate receptor mGluR1 is required for EBC although the molecular mechanisms are not fully understood. Here we show that infusion of the mGluR1 …

Effects Of Tumor-Related Factors And Chemotherapy On Skeletal Muscle And The Protective Effects Of Exercise, Blas Anselmo Guigni

Graduate College Dissertations and Theses

Cancer patients often experience cachexia, a form of weight loss consisting mostly of skeletal muscle wasting. Muscle wasting leads to physical disability, poor quality of life, reduced tolerance to treatments and shorter survival. Although the causes of cancer-related muscle atrophy have been studied for decades, the exact mechanisms through which cancer and its treatments promote muscle wasting have yet to be defined.

The overall aim of this dissertation is to examine the mediators of muscle wasting in cancer patients during their treatment and examine the modulatory role of exercise to maintain muscle size and function. To address these aims, we …

Neurodevelopmental Roles Of Semaphorin6a/Plexina2 Signaling In Zebrafish, Sarah Elizabeth Emerson

Graduate College Dissertations and Theses

ABSTRACT

A multitude of complex cellular changes are required throughout development in order for a single cell to transform into a fully functioning organism. Cellular events including proliferation, migration, and differentiation have to be carefully controlled in order for development to proceed correctly. In order to study such dynamic processes, in vivo models are often utilized. Using the zebrafish (Danio rerio) as a model system, we have investigated the role of an axon guidance signaling pair, Semaphorin6A (Sema6A) and PlexinA2 (PlxnA2), in neurodevelopment.

A previous investigation into the developmental expression patterns of sema6A and plxnA2 in zebrafish, revealed overlapping expression …

Exosomes And Their Role In Asbestos Exposure And Mesothelioma, Phillip Blake Munson

Graduate College Dissertations and Theses

Malignant mesothelioma (MM) is a locally invasive and highly aggressive cancer arising on the mesothelial surface of organ cavities (mainly pleural) as a direct result of asbestos exposure. The latency period of MM is long (20-50yrs) after initial asbestos exposure, and the prognostic outcomes are dismal with median life expectancy of 6-12 months post-diagnosis. There are no useful biomarkers for early MM diagnosis, no successful therapeutic interventions. These vast voids of knowledge led to our hypotheses that secreted vesicles, termed exosomes, play an important role in MM development and tumorigenic properties. Exosomes are nano-sized particles secreted from all cell types …

Inflammation Of The Taste Sensory System: Cyclophosphamide And Amifostine, Anish Ali Sarkar

Graduate College Dissertations and Theses

Chemotherapeutics are used extensively to treat cancer patients and often induce adverse effects, including taste dysfunctions. Disturbances in taste are detrimental to the overall well-being of cancer patients, causing malnutrition and weight loss that aggravate their condition even further. Inflammation due to an infection of the taste sensory system as previously shown, has detrimental effects on the taste sensation. Our study focused on if chemotherapy induced an inflammatory response in the taste buds using cyclophosphamide (CYP), a pro-drug. Once metabolized by the P450 enzyme complex, its primary metabolite functions as an alkylating agent, involved in inhibiting cell replication cycle and …

A Proximity-Dependent Biotin Labeling Based Screen For Protein Kinase A Anchoring Proteins Within Focal Adhesion Complexes, Hannah Naughton

Graduate College Dissertations and Theses

Protein kinase A (PKA) regulates a diverse array of cellular activities including metabolism, differentiation, actomyosin contractility, and migration. The multifunctionality of this ubiquitous enzyme is achieved, in part, through subcellular targeting mediated by the A Kinase Anchoring Proteins (AKAP) family of proteins. AKAPs serve as scaffolding proteins that localize PKA to various cellular compartments and bring together specific targets and modulators of PKA activity.

The importance of spatially restricted PKA signaling is particularly apparent in the context of cell motility. It has been observed that both anchoring through AKAPs and the subsequent localized activation of PKA at the leading edge …

Multiple Functions Of The Striated Rootlet Proteins Of The Paramecium Basal Body, Md Ashikun Nabi

Graduate College Dissertations and Theses

Paramecium ciliary basal bodies align in straight rows from posterior to anterior. Each basal body is connected to three rootlets ((Post Ciliary Rootlet (PCR), Transverse Rootlet (TR) and Striated Rootlet (SR)). The SR, the longest, projects from the basal body toward the anterior past several more anterior basal bodies. The depletion of Meckelin (MKS3) misaligns SRs, disorganizes basal body rows and makes the SRs appear ragged and serpentine. In this study we clarify the composition of the Paramecium ciliary basal body’s SR and demonstrate that the SR plays a critical role in creating the orderly array of basal bodies in …

'Crk'-Ing The Code: The Role Of Crk Adaptor Proteins In Zebrafish Eye Development, Helaina Renee Stergas

Graduate College Dissertations and Theses

The migration of neurons from their place of birth to their place of function is an important process during neurodevelopment. Two adaptor proteins, Crk and Crkl, are known to be important factors for neuronal migration. In the neocortex, both molecules play a critical role in the well studied Reelin signaling pathway, guiding newly born neurons to their correct cell layer to create the laminated structure of this tissue. These two adaptor proteins are implicated in human disease of the nervous system. Heterozygous compound deletion of human chromosome 17p13, which includes CRK, occurs in Miller-Dieker syndrome, a severe type of lissencephaly …

Arenavirus Transcription, Replication, And Interaction With Host-Cellular Components, Benjamin King

Graduate College Dissertations and Theses

Arenaviruses are enveloped negative-strand RNA viruses that cause significant human disease. Despite decades of research, it is still unclear how these viruses establish a lifelong, asymptomatic infection in their rodent hosts while infection of humans often results in severe disease. Unable to enter a state of bona fide latency, the transcription and replication of the viral genomic RNA is likely highly regulated in time and subcellular space. Moreover, we hypothesize that the viral nucleoprotein (NP), responsible for the encapsidation of the viral RNA and the most highly expressed viral gene product, plays a key role in the regulation of the …

Evidence For The Involvement Of Runx1 And Runx2 In Maintenance Of The Breast Cancer Stem Cell Phenotype, Mark Fitzgerald

Graduate College Dissertations and Theses

In the United States, metastatic breast cancer kills approximately 40,000 women and 400 men annually, and approximately 200,000 new cases of breast cancer are diagnosed each year. Worldwide, breast cancer is the leading cause of cancer deaths among women. Despite advances in the detection and treatment of metastatic breast cancer, mortality rates from this disease remain high because the fact is that once metastatic, it is virtually incurable. It is widely accepted that a major reason breast cancer continues to exhibit recurrence after remission is that current therapies are insufficient for targeting and eliminating therapy-resistant cancer cells. Emerging research has …

Temporal Coordination Of Mitotic Chromosome Alignment And Segregation: Structural And Functional Studies Of Kif18a, Haein Kim

Graduate College Dissertations and Theses

Chromosome alignment is highly conserved in all eukaryotic cell divisions. Microtubule (MT) -based forces generated by the mitotic spindle are integral for proper chromosome alignment and equal chromosome segregation. The kinetochore is a multi-subunit protein complex that assembles on centromeric regions of chromosomes. Kinetochores tether chromosomes to MTs (K fibers) that emanate from opposite poles, in a process called biorientation. This linkage translates K fiber dynamics into chromosome movements during alignment and segregation. Stable, high-affinity kinetochore attachments promote spindle assembly checkpoint (SAC) silencing, which is active when unattached kinetochores are present. During chromosome alignment, 1) K fiber plus-end dynamics decrease, …

Characterization Of A Novel Vps26c-Retromer Complex And Its Interaction With An Endosomal Trafficking Pathway Regulated By The Snare Vti13 In Controlling Polarized Growth And Cell Wall Organization In Arabidopsis Thaliana, Suryatapa Ghosh Jha

Graduate College Dissertations and Theses

The endosomal trafficking system is a network of highly coordinated cellular pathways that control the growth and function of cells. The coordination of secretion and endocytosis in cells is one of the primary drivers of polarized growth, where new plasma membrane and cell wall components are deposited at the growing apex. In plants, one of the cell types exhibiting polarized growth are the root hairs. Root hairs are regulated extensions of epidermal cells called trichoblasts and are essential for anchorage, absorption of water and nutrients, and plant-microbe interactions. In this thesis, I characterize a previously undescribed protein involved in retromer …