Cell and Developmental Biology Commons^™

Syntaxin 6- And Microtubule- Mediated Intracellular Trafficking Contributes To Golgi And Nuclear Translocation Of Egfr, Yi Du

Dissertations and Theses (Open Access)

Receptor-mediated endocytosis is well known for its degradation and recycling trafficking. Recent evidence shows that these cell surface receptors translocate from cell surface to different cellular compartments, including the Golgi, mitochondria, endoplasmic reticulum (ER), and the nucleus to regulate physiological and pathological functions. Although some trafficking mechanisms have been resolved, the mechanism of intracellular trafficking from cell surface to the Golgi is not yet completed understood. Here we report a mechanism of Golgi translocation of EGFR in which EGF-induced EGFR travels to the Golgi via microtubule (MT)-dependent movement by interacting with dynein and fuses with the Golgi through syntaxin 6 …

Chronic Stress Promotes Tumor Growth Through Increased Bdnf Production And Neo-Innervation, Julie K. Allen

Dissertations and Theses (Open Access)

Background: Activation of the sympathetic nervous system (SNS) in response to chronic biobehavioral stress results in high levels of catecholamines and persistent activation of adrenergic signaling, which promotes tumor growth and progression. However it is unknown how catecholamine levels within the tumor exceed systemic levels in circulation. I hypothesized that neo-innervation of tumors is required for stress-mediated effects on tumor growth.

Results: First, I examined whether sympathetic nerves are present in human ovarian cancer samples as well as orthotopic ovarian cancer models. Immunohistochemical (IHC) staining for neurofilament revealed that catecholaminergic neurons are present within tumor tissue. In order to determine …

Identification And Characterization Of Distinct Populations Of Clonogenic Bone Marrow Stromal Cells Capable Of Transferring The Hematopoietic Microenvironment In Vivo And Supporting Lt-Hscs In Vitro, Colby Suire

Dissertations and Theses (Open Access)

Bone marrow (BM) stromal cells are ascribed two key functions, 1) stem cells for non-hematopoietic tissues (MSC) and 2) as components of the hematopoietic stem cell niche. Current approaches studying the stromal cell system in the mouse are complicated by the low yield of clonogenic progenitors (CFU-F). Given the perivascular location of MSC in BM, we developed an alternative methodology to isolate MSC from mBM. An intact ‘plug’ of bone marrow is expelled from bones and enzymatically disaggregated to yield a single cell suspension. The recovery of CFU-F (1917.95+199) reproducibly exceeds that obtained using the standard BM flushing technique (14.32+1.9) …

Lmw-E Mediates Mammary Tumorigenesis By Deregulating Acinar Morphogenesis & Generating Cancer Stem Cells, Mylinh T. Duong

Dissertations and Theses (Open Access)

Cyclin E is the regulatory subunit of the cyclin E/CDK2 complex that

mediates the G1-S phase transition. N-terminal cleavage of cyclin E by elastase in

breast cancer generates two low molecular weight (LMW) isoforms that exhibit both

enhanced kinase activity and resistance to p21 and p27 inhibition compared to fulllength cyclin E. Clinically, approximately 27% of breast cancer patients overexpress

LMW-E and associate with poor survival. Therefore, we hypothesize that LMW-E

disrupts normal mammary acinar morphogenesis and serves as the initial route into

breast tumor development. We first demonstrate that LMW-E overexpression in

non-tumorigenic hMECs is sufficient to induce tumor …

Induced-Pluripotent Stem-Derived Neuronal Progenitor Cells As A Novel Treatment For Neurodegenerative Diseases, Dennisse A. Gonzalez-Romero

Dissertations and Theses (Open Access)

Cellular therapies, as neuronal progenitor (NP) cells grafting, are promising therapies for patients affected with neurodegenerative diseases like Creutzfeldt-Jakob Disease (CJD). At this time there is no effective treatment or cure for CJD. The disease is inevitably fatal and affected people usually die within months of the appearance of the first clinical symptoms. Compelling evidence indicate that the hallmark event in the disease is the conversion of the normal prion protein (termed PrP^C) into the disease-associated, misfolded form (called PrP^Sc). Thus, a reasonable therapeutic target would be to prevent PrP misfolding and prion replication. This strategy …

Increased Geranylgeranylated K-Ras Contributes To Antineoplastic Effects Of Farnesyltransferase Inhibitors., Mandy A. Hall

Dissertations and Theses (Open Access)

The Ras family of small GTPases (N-, H-, and K-Ras) is a group of important signaling mediators. Ras is frequently activated in some cancers, while others maintain low level activity to achieve optimal cell growth. In cells with endogenously low levels of active Ras, increasing Ras signaling through the ERK and p38 MAPK pathways can cause growth arrest or cell death. Ras requires prenylation – the addition of a 15-carbon (farnesyl) or 20-carbon (geranylgeranyl) group – to keep the protein anchored into membranes for effective signaling. N- and K-Ras can be alternatively geranylgeranylated (GG’d) if farnesylation is inhibited but are …

Regulation Of Protein Degradation In The Heart By Amp-Activated Protein Kinase, Kedryn K. Baskin

Dissertations and Theses (Open Access)

The degradation of proteins by the ubiquitin proteasome system is essential for cellular homeostasis in the heart. An important regulator of metabolic homeostasis is AMP-activated protein kinase (AMPK). During nutrient deprivation, AMPK is activated and intracellular proteolysis is enhanced through the ubiquitin proteasome system (UPS). Whether AMPK plays a role in protein degradation through the UPS in the heart is not known. Here I present data in support of the hypothesis that AMPK transcriptionally regulates key players in the UPS, which, under extreme conditions can be detrimental to the heart. The ubiquitin ligases MAFbx /Atrogin-1 and MuRF1, key regulators of …

Regulation Of Protein Degradation In The Heart By Amp-Activated Protein Kinase, Kedryn K. Baskin, Kedryn K. Baskin

Dissertations and Theses (Open Access)

The degradation of proteins by the ubiquitin proteasome system is essential for cellular homeostasis in the heart. An important regulator of metabolic homeostasis is AMP-activated protein kinase (AMPK). During nutrient deprivation, AMPK is activated and intracellular proteolysis is enhanced through the ubiquitin proteasome system (UPS). Whether AMPK plays a role in protein degradation through the UPS in the heart is not known. Here I present data in support of the hypothesis that AMPK transcriptionally regulates key players in the UPS, which, under extreme conditions can be detrimental to the heart. The ubiquitin ligases MAFbx /Atrogin-1 and MuRF1, key regulators of …

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

All Theses

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 …

Identification Of Amino Acids Essential For Estrone-3-Sulfate Transport Within Transmembrane Domain 2 Of Organic Anion Transporting Polypeptide 1b1, Nan Li, Weifang Hong, Hong Huang, Hanping Lu, Guangyun Lin, Mei Hong

School of Information Faculty Publications

As an important structure in membrane proteins, transmembrane domains have been found to be crucial for properly targeting the protein to cell membrane as well as carrying out transport functions in transporters. Computer analysis of OATP sequences revealed transmembrane domain 2 (TM2) is among those transmembrane domains that have high amino acid identities within different family members. In the present study, we identify four amino acids (Asp70, Phe73, Glu74, and Gly76) that are essential for the transport function of OATP1B1, an OATP member that is specifically expressed in the human liver. A substitution of these four amino acids with alanine …

Genome-Wide Identification Of Conditionally Essential Genes In Salmonella Typhimurium Using Tn-Seq Method, Anita Khatiwara

Graduate Theses and Dissertations

ABSTRACT

As more whole genome sequences become available, there is an increasing need for high-throughput methods that link genes to phenotypes and facilitate discovery of new gene functions. The objective of this study was to develop a high-throughput method to study gene functions in bacteria and use this method to study gene functions of S. enterica serotype Typhimurium (S. Typhimurium) under various environmental conditions encountered during its life cycle. Chapter I of this dissertation reviews the history and evolution of functional genomics in bacteria with focus on Salmonella, along with the recent techniques available. Chapter II, deals with the development …

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

All Dissertations

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. …

Electrospun Polycaprolactone Nanofiber Scaffolds For Tissue Engineering, Andreas Haukas

Graduate Theses and Dissertations

Stem cell and tissue engineering offer us with a unique opportunity to research and develop new therapies for treating various diseases that are otherwise incurable using traditional medicines. However, development of these new therapies replies upon the establishment of in vitro cell culture and differentiation systems that mimic in vivo microenvironments required for cell-cell and cell-ECM interaction. The development of these cell culture systems depends upon the identification of appropriate biomaterials and cell sources. Biomaterials should be carefully selected and fabricated into scaffolds for supporting cell growth and differentiation. In this study, we explored the fabrication of 3D electrospun nanofiber …

Molecular Analysis And Localization Of A Novel Dictyostelium Discoideum Rab Protein, Rabs, Katherine V. Maringer

Theses and Dissertations

Functional analysis and localization of the small GTPase RabS in the slime mold, Dictyostelium discoideum, was explored using cell lines that over-express a GFP tagged RabS protein. Based on homology to Rab1, Golgi association was explored. Immunofluoresence analysis of the intracellular localization of this GFP tagged protein revealed that this GFP-Rab had a partial co-localization with the contractile vacuole organelle system. Additionally, when the over-expressed RabS cell lines were exposed to selective biochemical inhibitors, the GFP-Tagged Rab localized with what can be assumed is the Golgi network. This dual localization of Golgi and CV may support a previously proposed connection …

Analysis Of The Effects And Current Treatments Of Laminin Deficiency, Joshua Mark Reynolds

Senior Honors Theses

Laminin (LM) is a network of proteins that functions as a connective framework of most cells in the body. It is composed of multiple different subunits and therefore has many different variations. It is a trimeric protein, meaning that it is composed primarily of ⍺, β, and γ chains. The differentiation of these subunits is what gives the different variants their functions. In addition, although LM is the primary molecule in scope, the network of other connective proteins involved in LM-associated diseases will also be covered in lesser detail because molecules like dystrophin, dystroglycan, collagen, and integrin are vital to …

Natural Reward Experience Alters Ampa And Nmda Receptor Distribution And Function In The Nucleus Accumbens, Kyle K. Pitchers, Susanne Schmid, Andrea R. Di Sebastiano, Xu Wang, Steven R. Laviolette, Michael N. Lehman, Lique M. Coolen

Anatomy and Cell Biology Publications

Natural reward and drugs of abuse converge upon the mesolimbic system which mediates motivation and reward behaviors. Drugs induce neural adaptations in this system, including transcriptional, morphological, and synaptic changes, which contribute to the development and expression of drug-related memories and addiction. Previously, it has been reported that sexual experience in male rats, a natural reward behavior, induces similar neuroplasticity in the mesolimbic system and affects natural reward and drug-related behavior. The current study determined whether sexual experience causes long-lasting changes in mating, or ionotropic glutamate receptor trafficking or function in the nucleus accumbens (NAc), following 3 different reward abstinence …

Iron Deficiency Causes A Shift In Amp-Activated Protein Kinase (Ampk) Catalytic Subunit Composition In Rat Skeletal Muscle, John Merrill

Theses and Dissertations

To determine effects of iron deficiency on AMPK activation and signaling, as well as the AMPKα subunit composition in skeletal muscle, rats were fed a control (C=50-58 mg/kg Fe) or iron deficient (ID=2-6 mg/kg Fe) diet for 6-8 wks. Their respective hematocrits were 47.5% ± 1.0 and 16.5% ± 0.6. Iron deficiency resulted in 28.3% greater muscle fatigue (p<0.01) in response to 10 min of stimulation (1 twitch/sec) and was associated with a greater reduction in phosphocreatine (C: Resting 24.1 ± 0.9 micromol/g, Stim 13.1 ± 1.5 micromol/g; ID: Resting 22.7 ± 1.0 micromol/g, Stim 3.2 ± 0.7 micromol/g; p<0.01) and ATP levels (C: Resting 5.89 ± 0.48 micromol/g, Stim 6.03 ± 0.35 micromol/g; ID: Resting 5.51 ± 0.20 micromol/g, Stim 4.19 ± 0.47 micromol/g; p<0.05). AMPK activation increased with stimulation in muscles of C and ID animals. A reduction in Cytochrome c and other iron-dependent mitochondrial proteins was observed in ID animals (p<0.01). The AMPK catalytic subunit (alpha) was also examined because both isoforms are known to play different roles in responding to energy challenges. In ID animals, AMPK alpha2 subunit protein content was reduced to 71.6% of C (p<0.05), however this did not result in a significant difference in resting AMPK alpha2 activity. AMPK alpha1 protein was unchanged, however an overall increase in AMPK alpha1 activity was observed (C: 0.91 pmol/mg/min; ID: 1.63 pmol/mg/min; p<0.05). Resting phospho Acetyl CoA Carboxylase (pACC) was unchanged. This study indicates that chronic iron deficiency causes a shift in the expression of AMPK alpha subunit composition and potentially altered sensitivity to cellular energy challenges.

Viral Receptor Trafficking Regulated By Gabarap, Cendy Valle Oseguera, Carolyn C. Tu, Jie Sun, Kathleen Arnolds, Juliet V. Spencer

Creative Activity and Research Day - CARD

Human cytomegalovirus (HCMV) is a widespread pathogen that can be life-threatening to immune-compromised patients but rarely causes disease in healthy individuals. Previous work using the yeast two-hybrid system found that GABARAP (γ-aminobutyric-acid-receptor-associated-protein) binds to HCMV US27. US27 is similar to human chemokine receptors, but is localized intracellularly instead of on the surface. Here, we examined the US27-GABARAP interaction in human cells and identified a four amino acid motif (WXXL) that mediates GABARAP binding to US27 and its localization to endosomal compartments. Since GABARAP regulates cellular receptor trafficking, these results show that viral US27 is also controlled by a cellular protein.

Role Of Human Cytomegalovirus In Breast Cancer, Cendy Valle Oseguera, Juliet V. Spencer

Creative Activity and Research Day - CARD

Cancer results from unregulated cell growth that invades neighboring tissues. While there are many known risk factors for cancer, one area that remains largely unexplored is the impact of infectious disease. Human cytomegalovirus (HCMV) is highly prevalent in the population and has also been found in several types of tumors. We are investigating the possibility that a viral protein released from infected cells, cmvIL-10, promotes tumor metastasis by enhancing the invasive potential of breast cancer cells. These results will clarify the role of HCMV in breast cancer progression and could have broad implications for the diagnosis and treatment of cancer.

Analysis Of Her-2 Positive Breast Cancer Cell Lines, Natzidielly Lerma^, Paloma Valenzuela, Karla Parra, Eduardo Ramirez, Courtney L. Becerril, Irving Miramontes, Cynthia M. Rodriguez, Elizabeth Gamez, Giulio Francia*

COURI Symposium Abstracts, Spring 2012

No abstract provided.