Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 31 - 49 of 49

Full-Text Articles in Life Sciences

Brown Adipogenesis Of Mouse Embryonic Stem Cells In Alginate Microstrands, Andrea Mannarino Unser Jan 2015

Brown Adipogenesis Of Mouse Embryonic Stem Cells In Alginate Microstrands, Andrea Mannarino Unser

Legacy Theses & Dissertations (2009 - 2024)

The ability of brown adipocytes (fat cells) to dissipate energy as heat shows great promise for the treatment of obesity and other metabolic disorders. Employing pluripotent stem cells, with an emphasis on directed differentiation, may overcome many issues currently associated with primary fat cell cultures. However, brown adipocytes are difficult to transplant in vivo due to the instability of fat, in terms of necrosis and neovascularization, once injected. Thus, 3D cell culture systems that have the potential to mimic adipogenic microenvironments are needed, not only to advance brown fat implantation, but also to better understand the role of brown adipocytes …


A Novel Method For Studying Gene Regulatory Elements In Vivo Reveals Essential Roles For Intron Splicing In Neurofilament Gene Expression, Chen Wang Jan 2015

A Novel Method For Studying Gene Regulatory Elements In Vivo Reveals Essential Roles For Intron Splicing In Neurofilament Gene Expression, Chen Wang

Legacy Theses & Dissertations (2009 - 2024)

Axon outgrowth requires coordinated expression of critical cytoskeletal genes in response to extracellular cues. The spatial and temporal expression of these genes is regulated transcriptionally and posttranscriptionally. Such regulation is largely mediated through the activity of cis-regulatory elements within the cytoskeletal DNAs and RNAs, which recruit specific sets of trans-factors such as DNA- and RNA-binding proteins, as well as microRNAs. To identify the functionally active cis-elements, characterize their dynamically changing sets of trans-factors, and investigate the association between the two sets of regulators in the context of an intact developing nervous system, one needs to combine appropriate in vivo strategies …


Mouse Salivary Gland Development Requires Optimal Substrate Compliance, Sarah Beth Peters Jan 2014

Mouse Salivary Gland Development Requires Optimal Substrate Compliance, Sarah Beth Peters

Legacy Theses & Dissertations (2009 - 2024)

The embryonic mouse submandibular salivary gland (mSMG) is a classic model to study mechanochemical signals involved in morphogenesis and differentiation amongst multiple, interacting cell populations. Scaffold compliance is alters cellular phenotype, but little is known about the effects of compliance on organogenesis. The overall aim of this project was to demonstrate that the processes of salivary gland epithelial branching morphogenesis and differentiation require a compliant, in vivo-like environment and are disrupted outside of this range.


Computational Modeling-Driven Study Of Signaling Pathway Affecting Cleft Formation During Submandibular Salivary Gland Development, Shayoni Ray Jan 2014

Computational Modeling-Driven Study Of Signaling Pathway Affecting Cleft Formation During Submandibular Salivary Gland Development, Shayoni Ray

Legacy Theses & Dissertations (2009 - 2024)

Branching morphogenesis is a conserved mechanism of mammalian organ development (salivary glands, lungs, mammary glands, pancreas, kidney, etc.), and has been a classic topic of study for generations of developmental biologists. During the process of tissue formation, several cellular and molecular and protein signaling events occur at successive stages enabling proper formation of tissue shape and structure. In order to provide a comprehensive understanding of the process of branching morphogenesis, we need a systems level approach to integrate multifactorial information. My overall global hypothesis is that multiple mathematical modeling approaches can be utilized to extract crucial cellular and tissue level …


The Lipogenic Phenotype Of Her2/Neu-Positive Breast Cancer Cells, Jan Martin Baumann Jan 2014

The Lipogenic Phenotype Of Her2/Neu-Positive Breast Cancer Cells, Jan Martin Baumann

Legacy Theses & Dissertations (2009 - 2024)

Recent work has shown that HER2/neu-positive breast cancer cells rely on a unique Warburg-like metabolism for survival and aggressive behavior. These cells are dependent on fatty acid (FA) synthesis, show markedly increased levels of stored fats and disruption of the synthetic process results in apoptosis. Supplementation of the growth media with physiological concentrations of saturated FAs induces cell death, whereas HER2-normal cells are not affected. This is particularly interesting in the context of new epidemiological data showing that a diet rich in saturated FAs is positively correlated with the development of HER2-negative disease, but not HER2/neu-positive disease.


The Postsynaptic Regulation Of Synaptic Strength In Drosophila, Daniel Michael Gertner Jan 2014

The Postsynaptic Regulation Of Synaptic Strength In Drosophila, Daniel Michael Gertner

Legacy Theses & Dissertations (2009 - 2024)

Postsynaptic Ca2+ plays an important role in synaptic homeostasis and synaptic plasticity. Postsynaptic Ca2+ signals have been shown to regulate synaptic transmission at the Drosophila larval neuromuscular junction (NMJ), however, these signals have not been well characterized. This will explore how these signals regulate synaptic strength and what channels are involved. In previous lab experiments Ca2+ transients were observed during evoked and spontaneous release (Desai and Lnenicka, 2011). It was further demonstrated that a reduction in synaptic strength occurs following synaptic stimulation. It was hypothesized that the increase in postsynaptic Ca2+ following synaptic stimulation activates the gCS and causes a …


Molecular Actions Of The Vitamin D Receptor In Breast Cancer, Erika Laporta Jan 2014

Molecular Actions Of The Vitamin D Receptor In Breast Cancer, Erika Laporta

Legacy Theses & Dissertations (2009 - 2024)

1,25-Dihydroxyvitamin D (1,25D) exerts anti-cancer actions through the vitamin D receptor (VDR) but the specific targets that mediate these effects remain to be defined. In these studies, growth and genomic responses to 1,25D were evaluated in a cellular model system derived from mammary tumors generated in VDR knockout (KO) and wildtype (WT) mice. WT145 cells (derived from WT tumors) expressed VDR and were growth inhibited by 1,25D, whereas KO240 cells (derived from VDRKO tumors) lacked VDR and were not growth inhibited by 1,25D. KO240 cell clones stably expressing VDR (KOhVDR cells) were sensitized to 1,25D mediated growth arrest. Genomic profiling …


Mechanisms Of Age-Related Inflammation And Cancer : The Synergistic Effect Of Oxidants And Calcium, Donald A. Mccarthy Jan 2014

Mechanisms Of Age-Related Inflammation And Cancer : The Synergistic Effect Of Oxidants And Calcium, Donald A. Mccarthy

Legacy Theses & Dissertations (2009 - 2024)

The accumulation of senescent cells during the process of aging has been implicated as causal in numerous age-related pathologies. Senescent cells adopt a secretory phenotype consisting of many factors including matrix remodeling enzymes, growth factors, cytokines, and chemokines. Their secretory nature is the primary reason that they are associated with disease, but it remains unclear why they become so inflammatory. Using primary human fibroblasts cultured to senescence, we mechanistically determined why senescent cells are such potent inducers of inflammation. Our findings indicate that the early production of the cytokine Interleukin 1-α (IL-1α) is central to this transition. We found that …


Post-Translational Modification Regulates Heterogeneous Nuclear Ribonucleoprotein K Function During Axon Outgrowth In Xenopus Laevis, Erica J. Hutchins Jan 2013

Post-Translational Modification Regulates Heterogeneous Nuclear Ribonucleoprotein K Function During Axon Outgrowth In Xenopus Laevis, Erica J. Hutchins

Legacy Theses & Dissertations (2009 - 2024)

The RNA-binding protein, heterogeneous nuclear ribonucleoprotein K (hnRNP K), is required for axon outgrowth. Its suppression in Xenopus embryos causes defects in the translation of mRNAs of multiple cytoskeletal genes. Studies in cell lines have established that hnRNP K shuttles between the nucleus and the cytoplasm to bind and regulate the fates of its target RNAs, from splicing to export and translation. At each step, hnRNP K is regulated through post-translational modifications that alter its nucleic acid and protein interactions, and subcellular localization. Precisely how this happens in developing neurons to coordinate cytoskeletal gene expression with the extracellular signals directing …


Characterizing The Effects Of Glutaraldehyde On The Ryanodine Receptor Calcium Release Channel, Joshua Dov Strauss Jan 2013

Characterizing The Effects Of Glutaraldehyde On The Ryanodine Receptor Calcium Release Channel, Joshua Dov Strauss

Legacy Theses & Dissertations (2009 - 2024)

Ryanodine receptors (RyR) are large intracellular calcium release channels, which


Identification Of Trophic And Transcriptional Requirements For Human Embryonic Stem Cell Culture And Guided Neural Differentiation, Nicolas Edward Tokas Jan 2012

Identification Of Trophic And Transcriptional Requirements For Human Embryonic Stem Cell Culture And Guided Neural Differentiation, Nicolas Edward Tokas

Legacy Theses & Dissertations (2009 - 2024)

Translational biomedical research holds potential for the development of novel therapeutics for the treatment of injury, illness or disability. To better understand intrinsic cellular and molecular biology, human embryonic stem cells (hESCs) can be used as a tool. hESCs are pluripotent with the abilities to be held in a self-renewal state or become induced to a desired germ layer then to be later directed through differentiation.


The Role Of An Rna Binding Protein Hnrnp K During Axon Development And Regeneration In Xenopus Laevis, Yuanyuan Liu Jan 2012

The Role Of An Rna Binding Protein Hnrnp K During Axon Development And Regeneration In Xenopus Laevis, Yuanyuan Liu

Legacy Theses & Dissertations (2009 - 2024)

Coordinated synthesis and assembly of the cytoskeletal network contribute significantly to morphological changes during axon outgrowth. Previous studies demonstrated that heterogeneous ribonucleoprotein K (hnRNP K), an RNA binding protein, binds to the 3'-untranslated regions of all neurofilament triplet subunits, the most abundant components of the axonal cytoskeleton. These findings raised the hypothesis that hnRNP K post-transcriptionally mediates the coordinated expression of axonal cytoskeletal components. In my thesis, I test this hypothesis during both axonal development and regeneration.


The P38 Alpha Stress-Activated Protein Kinase Pathway In Mammary Gland Development And Cancer, Huei-Chi Wen Jan 2011

The P38 Alpha Stress-Activated Protein Kinase Pathway In Mammary Gland Development And Cancer, Huei-Chi Wen

Legacy Theses & Dissertations (2009 - 2024)

Breast tumors arise from preinvasive lesions consisting of abnormal epithelial cells that accumulate within the mammary duct. However, the initiating steps and underlying pathways leading to the formation of these early stages of breast carcinoma, such as ductal carcinoma in situ (DCIS), is not fully understood.


Rho Kinase Regulates Basement Membrane Dynamics To Coordinate Salivary Gland Branching Morphogenesis And Tissue Organization, William Patrick Daley Jan 2011

Rho Kinase Regulates Basement Membrane Dynamics To Coordinate Salivary Gland Branching Morphogenesis And Tissue Organization, William Patrick Daley

Legacy Theses & Dissertations (2009 - 2024)

Branching morphogenesis is a developmental mechanism utilized by many organs, including the salivary gland, lung, kidney, and mammary gland, to increase the epithelial surface area for secretion or absorption. The embryonic submandibular salivary gland (SMG) is a classic model for studying tissue morphogenesis in three dimensions ex vivo. Salivary gland development requires distinct but overlapping processes: morphogenesis, the actual physical rearrangement of cells into complex three dimensional structures, and cytodifferentiation, the process by which these cells begin to take on their own specialized function. Polarization, or the organization of cells into a cohesive tissue structure, also occurs concurrently during organ …


Regulation Of The Aryl Hydrocarbon Receptor And The Signal Transducer And Activator Of Transcription 1 By Long-Term Estrogen Exposure In Breast Carcinoma Cells, Neal Englert Jan 2011

Regulation Of The Aryl Hydrocarbon Receptor And The Signal Transducer And Activator Of Transcription 1 By Long-Term Estrogen Exposure In Breast Carcinoma Cells, Neal Englert

Legacy Theses & Dissertations (2009 - 2024)

The risk of developing breast cancer is known to be associated with a woman's lifetime exposure to estrogens, both endogenous and exogenous. Increased exposure to estrogens stimulates cellular proliferation, which is a widely accepted theory of estrogen receptor positive mammary carcinogenesis. The molecular mechanisms of gene expression regulation in response to long-term estrogen exposure (LTEE) of MCF-7 breast cancer cells were addressed in this study, with a focus on the aryl hydrocarbon receptor (AHR) and signal transducer and activator of transcription 1 (STAT1).


A Breast Cancer Stem Cell Model Created From Mmtv-Pymt Mice Applicable To Human Breast Cancer, Denise Grant Lanza Jan 2011

A Breast Cancer Stem Cell Model Created From Mmtv-Pymt Mice Applicable To Human Breast Cancer, Denise Grant Lanza

Legacy Theses & Dissertations (2009 - 2024)

Cancer stem cells are the seeds of tumor growth, but there are limited cell-based methods that exist to study the properties of these cells. To create a model of breast cancer stem cells, we isolated tumors from MMTV-PyMT mice. Two out of the four different cell types isolated survived in culture, CD44+CD24- and CD24+CD49f+CD44low. We found that we could initiate tumors with as few as 10 cells injected subcutaneously in the hind leg or orthotopically in the cleared fat pad with CD24+ cells. However, we could not initiate tumors with injection of CD24- cells. We found a requirement for TICs …


The Role Of Trm9 In Stress Responses, Ashish Ravindra Patil Jan 2011

The Role Of Trm9 In Stress Responses, Ashish Ravindra Patil

Legacy Theses & Dissertations (2009 - 2024)

Cells need to respond appropriately to environmental changes in order to maintain homeostasis. The cellular response to an environmental stress is regulated at transcriptional, translational and post translational levels. The tRNA, which acts as an adaptor molecule between the mRNA and the protein, plays an important role in the translational regulation of cellular responses to stress and is one of the most heavily modified biomolecules. In Saccharomyces cerevisiae , the wobble uracil of the tRNA(3'-UCU-5') Arg, tRNA(3'-UUC-5') Glu and certain other specific tRNAs are modified to 5-methoxycarbonylmethyluridine (mcm5U) and 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) residues by the tRNA methyltransferase 9 (Trm9). Modifications at …


Live-Cell Studies On Mitotic Slippage In Humans, Daniela A. Brito Jan 2009

Live-Cell Studies On Mitotic Slippage In Humans, Daniela A. Brito

Legacy Theses & Dissertations (2009 - 2024)

Checkpoints are regulatory pathways that control the order and timing of specific cell-cycle events. In the presence of unattached/weakly-attached kinetochores, the mitotic checkpoint (MC) arrests cells in mitosis by inhibiting the degradation of cyclin B, the regulatory subunit of Cdk1 (cyclin dependent kinase 1). Checkpoints do not arrest cells permanently, and escaping mitosis with an unsatisfied MC requires cyclin B/Cdk1 inactivation. In yeast, this occurs through an “adaptation” mechanism involving inhibitory phosphorylations and/or Cdk1-inhibitors. To determine how vertebrate cells escape mitosis when the MC cannot be satisfied I conducted live-cell imaging and immunofluorescence studies on nocodazole-treated rat kangaroo (PtK) and …


An Rnai Screen Targeting The Protein Tyrosine Kinases Identifies Bruton's Tyrosine Kinase (Btk) As A Breast Cancer Cell Survival Factor, Cheryl Lynne Eifert Jan 2009

An Rnai Screen Targeting The Protein Tyrosine Kinases Identifies Bruton's Tyrosine Kinase (Btk) As A Breast Cancer Cell Survival Factor, Cheryl Lynne Eifert

Legacy Theses & Dissertations (2009 - 2024)

The receptor protein tyrosine kinases (RPTKs) and the non- receptor protein tyrosine kinases (PTKs) are among the most commonly up-regulated genes found in all types of cancers. Although, a large body of data implicates a majority of tyrosine kinases (TKs) in cancer, few have been extensively evaluated for any potential therapeutic benefit in any of the many subtypes of breast cancer. We have used RNA interference (RNAi) to perform a large-scale loss-of-function analysis to facilitate the identification of individual factors necessary for the survival of an ErbB2 positive breast cancer cell line. We have found that 30% of the TKs …