Cell and Developmental Biology Commons^™

Single Cell Pharmacodynamic Modeling Of Cancer Cell Lines, Arnab Mutsuddy

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Cancer is one of the leading causes of disease related death worldwide. Since the discovery of the genomic origins of cancer, targeted therapy has been developed towards specific mutations implicated for oncogenic transformation. However, current standard-of-care for mapping cancer patients to efficacious drug combination is often inadequate. The pathophysiology of tumor progression relies on the dysregulation of biomolecular pathways of which the topology and the dynamics challenge prognosis. Moreover, the overall genomic instability involved in disease states and the resulting inter-patient as well as intra-tumoral heterogeneity challenge rationalization of therapy and clinical decision-making. It highlights the need for the use …

Cellular Mechanism Of Pentagalloyl Gucose-Mediated Prevention And Reversal Of Abdominal Aortic Aneurysms, Greg Halsey

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Abdominal aortic aneurysm (AAA) has been the 15th leading cause of death in persons older than 55 for the past ten years in several Western countries, with rupture resulting in an almost 100% mortality rate. AAA is a focal dilation of the aorta characterized by progressive loss of elastin and vascular smooth muscle cells (SMCs), as well as persistent inflammatory response [1]. The only treatment for AAA is surgery; however, the mortality post-procedure is still 1-4%, with a 15-30% chance of morbidity [2].

Pentagalloyl glucose (PGG) treatment is effective in the reversal of AAA. While its stabilizing interactions with extracellular …

Characterization Of The Effects Of The Pyrazolopyrimidine Inhibitor Grassofermata (Nav-2729) In The Eukaryotic Pathogen Trypanosoma Brucei, Kristina Marie Parman

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The protozoan pathogen, Trypanosoma brucei, is the causative agent of sleeping sickness in humans and nagana in livestock in sub-Saharan Africa. T. brucei cycles between tsetse fly and mammalian hosts, and it is adapted to survive in diverse host tissues. Variant Surface Glycoprotein (VSG) plays a key role in immune evasion in the mammalian host. The VSG membrane anchor requires two myristates, 14-carbon saturated fatty acids (FAs) that are scarce in the host. T. brucei can synthesize FAs de novo, but also readily takes up exogenous FAs, despite lacking homologs to fatty acid uptake proteins found in other …

Photodynamic Therapy To Treat Triple Negative Breast Cancer In Vitro, Hunter S. Warren

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Triple negative breast cancer (TNBC) is the most resilient form of breast cancer, being one of the leading causes of death for women and making up 7% of all cancer deaths. Photodynamic therapy (PDT) offers a minimally invasive solution to TNBC as a passive-targeting treatment that reduces the need for other well established yet harsh treatments that can be taxing on the patient. PDT involves the use of a high-energy red light on the area of a tumor injected with photosensitizers (PS) that generate reactive oxygen species (ROS) in the tumor, triggering cell death. The PS tetra(hydroxyphenyl)chlorin (m-THPC) was used …

Methyltransferase, Glucose Adaptation, And Import Complex In Trypanosoma Brucei, Emily Knight

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Trypanosoma brucei is a kinetoplastid parasite responsible for human African trypanosomiasis (HAT) and nagana, a livestock wasting disease, which both endemic to sub-Saharan Africa. Unique to kinetoplastids are the specialized peroxisomes, named glycosomes, which compartmentalize the first several steps of glycolysis and gluconeogenesis, nucleotide sugar biosynthesis, and many other metabolic processes. Kinetoplastids are unique in that they have a single mitochondrion. In this work, I present the first study into SET domain proteins in any kinetoplastid parasites. We have characterized a predicted SET domain protein, TbSETD3, that localizes to the mitochondrion and a depletion of the protein results in growth …

Development Of A Novel Fluorescent Reporter Baculovirus Vector For Testing Promoters In Lepidopterans, Daniel Howard

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Testing gene expression patterns is an important process in learning more about an organism. The standard methods of rtPCR and RNASeq provide highly detailed data on specific expression patterns, but can be resource consuming if many different samples including genes or organisms must be tested. A potential alternative for studying expression is the use of a reporter system carried by a vector system that encodes fluorescent proteins under the control of promoters of interest. Many lepidopterans (moths) are pestiferous and better understanding of gene expression levels in lepidopterans, both endogenous and exogenous including from their viruses, would be beneficial. Baculoviruses …

The Role Of Fatty Acid Metabolism In The Pathogenesis Of Trypanosoma Brucei, Nava Poudyal

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Trypanosoma brucei is the protozoan parasite that causes African Sleeping Sickness in humans and nagana, a wasting disease in cattle. T. brucei completes its life cycle in two hosts, mammals and the tsetse fly insect vector. Due to the geographical restriction of the tsetse fly, the disease is endemic in sub-Saharan Africa. Both the insect and mammalian forms of the parasite need fatty acids to anchor their surface proteins. We worked on three projects on fatty acid metabolism and its role in immune evasion strategies of T. brucei. First, we assessed the role of T. brucei surface proteins in …

Developmental Effects Of Chronic Low-Level Arsenic Exposure In Mouse Embryonic Stem Cells And In Human Induced Pluripotent Stem Cells, M. Chiara Perego

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Arsenic is an environmental contaminant commonly found in food and drinking water. Exposure to arsenic during embryonic development has been linked to reduced muscle growth, disrupted muscle development and locomotor activity, impaired neurodevelopment, reduced IQ, impaired memory and learning deficits. While the mechanisms responsible for developmental changes following in utero exposure to arsenic are not well known, one possibility is that arsenic might disrupt proper cellular differentiation. Therefore, we aimed to investigate the mechanisms by which arsenic exposure could alter stem cell differentiation into neurons.

First, we continuously exposed P19 mouse embryonic stem (ES) cells to 0.1 μM (7.5 ppb) …

Heat Stress Response And Excystation In Entamoeba Histolytica, Irem Bastuzel

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Entamoeba histolytica is a water- and food-borne intestinal protozoan parasite that causes amoebiasis and liver abscess and is responsible for symptomatic disease in approximately 100 million people each year leading to ~ 100,000 deaths. The most common disease transmission follows the oral-fecal route, but it can also be transmitted by mechanical vectors such as animals carrying the amoeba from contaminated sources to water systems. In rare cases, disease transmission has been recorded in some patients in which men-to-men sexual practices were preferred.

The life cycle of E. histolytica starts through ingestion of infectious cysts, which are non-dividing, quadri-nucleated structures surrounded …

Investigations Into Avian Skeletal Adaptations And Spine Fusion Events, Tori Huey

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Avian dinosaurs evolved skeletal adaptations resulting in numerous fused spinal structures, like the synsacrum, present in extant birds. The synsacrum is a highly fused region necessary for stiffening the spine, and it fuses the spine to the pelvic ilium. Conventional wisdom suggests that fusion occurred in ovo during embryonic development via the cartilage matrix that patterns the future vertebrae. We show that post hatch birds have intervertebral discs separating all vertebrae of the spine, leading us to re-examine this notion in chickens up to 10 weeks of age. Intervertebral discs undergo constant remodeling, then degenerate and undergo tissue clearance, followed …

Characterization Of The Wee1 Homologues And The Investigation Of Factors Promoting Cellular Enlargement In Cryptococcus Neoformans, Rodney J. Colón Reyes

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Cryptococcus neoformans is an opportunistic fungal pathogen, infecting mainly immunocompromised individuals. As the main cause of cryptococcosis, it is responsible for over 180,000 deaths every year. As an environmental yeast, it has unique adaptations that allow it to proliferate in the human host. Among these adaptations its capacity to transition to an extreme phenotype known as Titan cells is of special interest to researchers. With sizes above 10 um and able to reach 70 um or more in cell size. This size is accompanied with a large vacuole, larger polysaccharide capsule, and an increased resistance to fluconazole (FLC). FLC is …

Unraveling The Genetic Architecture Of Somatic Embryogenesis In Upland Cotton, Adam M. Canal

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Somatic embryogenesis is the de novo development of asexual embryos because of the plasticity of the plant cell. In tissue culture, the biochemical and genetic mechanisms of dedifferentiated callus tissues can be reprogrammed to transdifferentiate into developed, polarized embryos, which can ultimately regenerate into whole plants. Although this rarely occurs in nature, scientists have exploited this process for decades to regenerate whole plants following gene transformation or for micropropagation. While some species are amenable to in vitro regeneration, upland cotton is particularly recalcitrant, with regenerative potential being confined to only several genotypes. The lack of elite, regenerable genotypes greatly restricts …

Effects Of 2,4-Di-Tert-Butylphenol On Osteogenic And Myogenic Differentiation Of Human Induced Pluripotent Stem Cells, Thanh-Bình Dương

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Synthetic phenolic antioxidants (SPAs) are a class of compounds used to increase the durability of polymers as well as to increase the shelf-life of food, cosmetics, and other personal care items. Of these SPAs is 2,4-di-tert-butylphenol (2,4-DBP). 2,4-DBP is primarily used in polyethylene crosspolymer pipes, which are now used as a replacement for the traditional copper pipes for household water distribution. However, 2,4-DBP has been found to leach from these pipes into the water, enabling a mode of exposure to humans. 2,4-DBP has been detected in human urine, serum, but more importantly, maternal serum, placenta, and cord blood. …

Exploring The Role Of Ampk In Nutrient Sensing And Signaling In The Human Parasite Trypanosoma Brucei, Jessica Jones

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African trypanosomes are protozoan parasites that cause the diseases African sleeping sickness and nagana, in humans and cattle respectively. These parasites have complex life cycles with infection of a mammalian host, ~5mM glucose, following transmission by an insect vector, essentially zero glucose. With these pathogens being exposed to rapidly changing glucose abundance in a host-dependent manner, the ability to sense and rapidly respond to changes in the availability of the hexose are critical. First, I provide a review of glucose metabolism in Trypanosoma brucei. Then, we explore the role of the catalytic α subunit of AMPK, a eukaryotic master …

Arsenic Targets Neural Plate Border Specifier Cells In P19 Cells, Christopher Mccoy

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Epidemiological studies have shown that arsenic exposure during early embryogenesis can cause reduced weight gain and neurological deficits later on in life. In addition, in vitro and in vivo studies have indicated that arsenic suppresses neurogenesis and myogenesis. The exact mechanism of how arsenic causes these undesired developmental outcomes is poorly understood, however both skeletal muscle and sensory neuron development require the Wnt/β-catenin signaling pathway to initiate the specific differentiation of precursor cells. We were interested in determining the target cell population of arsenic and its metabolites. Arsenic's metabolites were of interest because they have been shown to be more …

A Novel Gain Of Function Of The Irx1 And Irx2 Genes Disrupts Axis Elongation In The Araucana Rumpless Chicken, Nowlan Freese

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Caudal dysplasia describes a range of developmental disorders that affect normal development of the lumbar spinal column, sacrum and pelvis. An important goal of the congenital malformation field is to identify the genetic mechanisms leading to caudal deformities.
To identify the genetic cause(s) and subsequent molecular mechanisms I turned to an animal model, the rumpless Araucana chicken breed. Araucana fail to form vertebrae beyond the level of the hips. I performed a genome wide association study to identify candidate genomic regions associated with the rumpless phenotype, compared to tailed Araucana. A candidate region of chromosome 2 containing just two genes, …

Early Skeletal Morphogenesis: The Role Of Pharyngeal Endoderm Derived Signaling During Specification Of Craniofacial Skeleton And Interplay Of Mechanical Forces And Molecular Signaling During Skeletal Condensation, Poulomi Ray

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This study examines the fundamental principles governing the early
stages of skeletal morphogenesis. I specifically investigate the specification of mesenchymal progenitor cells to a skeletal fate. Using explant culture system, I determine that the pharyngeal endoderm was sufficient, but not necessary for specifying pre-chondrogenic identity. FGF signaling is both sufficient and required for specification of Sox9 expression and specification of prechondrogenic identity, as demonstrated by the addition of recombinant FGF protein or the FGF receptor inhibitor (SU5402) to explanted tissue, respectively. However, FGF signaling cannot maintain Sox9 expression or initiate the chondrogenic program as indicated by the absence of Col2a1 …

The Role Of Acetyl-Coa Carboxylase In The Survival Of Trypanosoma Brucei During Infection, Ciara Mcknight

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This master's thesis focuses on how disruption of fatty acid metabolism affects both host adaptation and immune evasion in the deadly eukaryotic parasite, Trypanosoma brucei. In Chapter 1, I review the current literature on African trypanosomiasis, fatty acid synthesis, immune evasion, and lipid metabolism. In Chapter 2, I investigate how disruption of the fatty acid synthesis pathway affects the parasite's ability to evade the host immune defenses. When T. brucei acetyl-CoA carboxylase (TbACC) is knocked down by RNA interference (RNAi), fluid phase and receptor mediated endocytosis pathways are greatly affected, suggesting that fatty acid synthesis is necessary for both endocytic …

Specification Of The Neural Crest-Derived Pharyngeal Mesenchyme: The Role Of Pharyngeal Endoderm, Fgf And Bmp Signaling In The Establishment Of Prechondrogenic Identity And Initiation Of Chondrogenesis., Megha Kumar

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This study investigates the role of pharyngeal endoderm in the specification of prechondrogenic identity and initiation of chondrogenesis in the proximal mesenchyme of the second pharyngeal arch. The results show that pharyngeal endoderm is sufficient but not necessary for specification of prechondrogenic identity in the cranial neural crest derived arch mesenchyme. A number of Fgf genes - Fgf3, 4, 8 and 19 are expressed in the pharyngeal endoderm. Further, FGF signaling is sufficient and required for the specification of prechondrogenic identity, marked by Sox9 expression. However, FGF signaling is unable to maintain the Sox9 expression and initiate the chondrogenic program. …

Internalization Of F-Actin Monomers Into 3t3 Fibroblasts Via Thermal Inkjet Printing For Investigation Of Cytoskeleton Incorporation And Mechanics, Stephen Shuford

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ABSTRACT
We will review the conversion of a standard thermal inkjet printer into a bioprinting system and the effects of printing F-actin monomers with cells. The use of any printing system along with biological material or for biological or medical use has been termed bioprinting. Bioprinting has been used in vascular grafts, scaffold design, gene transfection, micro patterning and many other applications and is very diverse. Specifically we will look at the internalization of F-actin monomers into 3T3 fibroblasts as a result of cell membrane disruption from thermal inkjet printing. If the actin monomers were internalized and then incorporated into …

Mult1e-Rgd Fusion Protein Drives Nk Cell-Mediated Anti-Tumor Response, Meg Steiner

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A growing body of evidence indicates that natural killer (NK) cells are paramount to the identification and elimination of cancerous and pre-cancerous cells during normal immunosurveillance. In addition, NK cells provide a vital link between the innate and adaptive immune systems during an anti-tumoral response. In the present study, a novel fusion protein was designed from the extracellular portion of mouse UL16-binding protein-like transcript 1 (MULT1), a ligand for the activating NKG2D receptor on NK cells, and a short arginine-glycine-aspartic acid (RGD) -containing peptide, which binds the integrin αvβ3 of tumor-specific neovasculature. In vitro studies showed that the fusion protein …

Inhibition Of Pi 3-Kinase Signaling Contributes To Metronidazole Resistance In The Protozoan Parasite, Entamoeba Histolytica, Rhonda Powell

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Amoebiasis is defined as an intestinal infection with the human protozoan parasite, Entamoeba histolytica; approximately 100,000 deaths annually can be attributed to amoebiasis. Disease states range from asymptomatic colonization to invasive amoebiasis, characterized by abdominal pain and dysentery. Dissemination to extraintestinal sites, such as the liver and/or brain, can occur. Vesicle trafficking is critical for parasite virulence, and multiple signaling cascades within the pathogen facilitate these events.
One important regulator of signal transduction is the tightly controlled PI 3-kinase (PI3K), which phosphorylates the lipid, phosphatidylinositol bisphosphate (PIP₂), producing phosphatidylinositol trisphosphate (PIP₃). Effector proteins, such as Akt, …

Functional Interaction Of Racf2 And The Wasp Family Protein, Scar, In The Rab8 Signaling Pathway Of The Social Amoeba, Dictyostelium Discoideum, Terri Bruce

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The small GTPase, Rab8, has been shown to play a role in cell-cell adhesion and restructuring of the actin cytoskeleton in both mammalian cells and the lower eukaryote, Dictyostelium discoideum. In D. discoideum, cells expressing constitutively activated Rab8 (Rab8CA) display reduced cell-cell adhesion and increased actin-rich protrusions as well as delayed aggregation. Rab8 has been implicated in the restructuring of the actin cytoskeleton, but no specific pathway for this action has been identified. In other systems, actin-rich membrane extension formation is regulated by WASp family proteins, including SCAR. Here we provide evidence of a functional relationship between the WASp family …

Construction And Characterization Of A Novel Fusion Protein From The Extracellular Domain Of Mult1 And Transmembrane And Intracellular Domains Of Fas And Its Therapeutic Evaluation For Cancer Treatment Using An Adenoviral Delivery System, Hari Shankar Kotturi Rajeshwar

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One of the strategies that tumor cells adopt to evade immunosurveillance mounted by elements of the innate immune system, such as NK cells, is to down-regulate certain cell surface molecules through a process also called shedding. Mouse UL16-binding protein-like transcript 1 (MULT1), which can activate NK cells through NK cell receptor NKG2D, is one of such molecules. Tumor cells can also avoid Fas mediated apoptosis by down-regulating its expression, secreting antagonistic `decoy' receptors, or expressing anti-apoptotic molecules. In this study, we report the design and evaluation of the antitumor activity of a novel fusion protein MULT1E/FasTI, consisting of the extracellular …

The Development And Analysis Of A Closed System Of Vitrification For Mammalian Embryos, Jennifer Graves-Herring

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Embryo cryopreservation is an integral part of assisted reproduction because it allows for future use of these embryos. Cryopreservation occurs when there are supernumerary embryos or when an embryo transfer cannot be performed.
There are two main methods to cryopreserve embryos. The most recent is vitrification, which uses high concentrations of cryoprotectants, a short time to cool and avoids ice crystals. The 'gold standard' is the slow-cool method, which uses low concentrations of cryoprotectants, a long time to cool embryos and produces extracellular ice crystals.
Prior to introducing vitrification as part of the human cryopreservation regime, it is important that …

Characterization Of Phosphatidylinositol (3,4,5)-Trisphosphate Subcellular Localization During Endocytosis In Entamoeba Histolytica, Yevgeniya Byekova

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Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. Currently, the World Health Organization estimates that amoebic dysentery results in 40,000-100,000 deaths annually worldwide, which places amoebiasis second only to malaria as a leading cause of death due to parasitic infection. The pathogenesis of invasive amoebiasis depends on the parasite's ability to carry out endocytosis in the host's bowel lumen enabling it to colonize the digestive tract. The pathogen is contracted by the ingestion of its multinucleate cysts. Upon excystation in the small intestine, motile trophozoites are released into the bowel lumen, where bacteria, erythrocytes, and …

Tendon And Ligament Repair: Regeneration And Maturation, Jing Zhao

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The thesis constitutes the studies about the two aspects of tendon and ligament tissue engineering: regeneration and maturation. Injuries to tendon and ligament are among the most common injuries to the body, particularly in the young and physically active population. Associated with the problems of incomplete healing and recurrent injury, these injuries are not only responsible for large health care cost, but also result in lost work time and individual morbidity. Tissue engineering holds promise in treating these conditions by replacing the injured tissue with engineered tissue exhibited similar mechanical and functional characteristics. Collagen plays a central role in tendon …