Cell and Developmental Biology Commons^™

Antiviral Responses In Mouse Embryonic Stem Cells: Differential Development Of Cellular Mechanisms In Type I Interferon Production And Response, Ruoxing Wang

Dissertations

Embryonic stem cells (ESCs) have been recognized as a promising cell source for regenerative medicine. Intensive research over the past decade has led to the possibility that ESC-derived cells will be used for the treatment of human diseases. However, increasing evidence indicates that ESC-derived cells generated by the current differentiation methods are not fully functional. It is recently recognized that ESC-derived cells lack innate immunity to a wide range of infectious agents and inflammatory cytokines. When used in patients, ESC-derived cells would be placed in wounded sites that are exposed to various pathogens and inflammatory cytokines; therefore, their viability and …

Complexity And Familiarity Enhance Single-Trial Detectability Of Imagined Movements With Electroencephalography, Raechelle M. Gibson, Srivas Chennu, Adrian M. Owen, Damian Cruse

Anatomy and Cell Biology Publications

Objective: We sought to determine whether the sensorimotor rhythms (SMR) elicited during motor imagery (MI) of complex and familiar actions could be more reliably detected with electroencephalography (EEG), and subsequently classified on a single-trial basis, than those elicited during relatively simpler imagined actions. Methods: Groups of healthy volunteers, including experienced pianists and ice hockey players, performed MI of varying complexity and familiarity. Their electroencephalograms were recorded and compared using brain-computer interface (BCI) approaches and spectral analyses. Results: Relative to simple MI, significantly more participants produced classifiable SMR for complex MI. During MI of performance of a complex musical piece, the …

Effects Of Leptin On Established Glioblastoma Cell Lines, Nicholas J. Cook

All NMU Master's Theses

Glioblastoma is one of the most difficult cancers to treat because it is aggressive and resistant to therapy. The discovery of new therapeutic targets is drastically needed as zero improved treatment options have been added to the standard of care over the past 15 years. New and promising therapeutic targets are arising from psychosocial and environmental enrichment studies examining the role of stress in cancer progression. In animal models, eustress appears to slow tumor growth and recurrence resulting in increased overall survival and progression free survival while distress is associated with decreased overall survival. The cellular pathways activated by eustress …

Impedance Biosensors For The Rapid Detection Of Viral And Bacterial Pathogens Using Avian Influenza Virus Subtypes H5n1 And H7n2 And Escherichia Coli O157:H7 As Model Targets, Jacob David Lum

Graduate Theses and Dissertations

This research investigated impedance biosensors for the rapid detection of viral and bacterial pathogens using avian influenza virus (AIV) subtypes H5N1 and H7N2 and Escherichia coli O157:H7 as the model targets, which were chosen due to their impact on the agricultural and food industries. For the detection of AIV H7N2, a single stranded DNA aptamer was selected using systematic evolution of ligands by exponential enrichment (SELEX). The selected aptamer and a previously selected aptamer against AIV H5N1 were used in a microfluidics chip with an embedded interdigitated array microelectrode to fabricate an impedance biosensor for specific detection of AIV H7N2 …

Strategies To Sensitize Bladder Cancer Cells To Small Molecule Inhibitors Targeting The Pi3k Pathway, Giovanni Nitti

Dissertations and Theses (Open Access)

After many years of cancer research, it is well accepted by the scientific community that the future cure for this disease lies in a personalized therapeutic approach. Anticipating therapeutic outcome based on the genetic signature of a tumor has become the new paradigm. The PI3K pathway represents an ideal target for bladder cancer, as many of the key proteins of this pathway are altered or mutated in this particular type of cancer. Several small molecule inhibitors have been developed to target this pathway, but their efficacy has been shown to be heterogeneous among different cell lines and mostly cytostatic but …

Mapping The Human Vasculature By In Vivo Phage Display, Julianna Bronk

Dissertations and Theses (Open Access)

In vivo phage display screenings by intravenous injection of a random phage-displayed peptide library allow for the selection of peptides that localize to specific vascular beds. At the University of Texas MD Anderson Cancer Center, we have had the opportunity to perform phage display screenings in cancer patients in order to select for cancer specific targets directly in humans. These targets serve to define biochemical diversity of endothelial cell surfaces and can be validated and explored towards the design of vascular-targeted pharmacology. In the most recent patient screen, samples were recovered from hepatocellular carcinoma (HCC) as well as 26 additional …

Cd56-Specific T Cells: Using Genetically Engineered T Cells To Redirect Specificity To A T Cell Expressed Antigen, Denise L. Crossland

Dissertations and Theses (Open Access)

The CD56 antigen is expressed on several deadly malignancies currently lacking long-term efficacious therapies. Chimeric antigen receptor (CAR) based immunotherapies have shown both safety and efficacy and even a curative ability in clinical trials, laying the foundation for applying CARs to new targets. Using T cells to target a T cell expressed antigen, such as CD56, seems counterintuitive in that the T cells would be susceptible to self-targeting a.k.a. fratricide. However, we expand CD56-specific CAR⁺ T cells that co-express the CD56 antigen. Since other CARs targeting T cell expressed antigens are hypothesized to be undergoing fratricide, such as the …

Controlling Pseudomonas Aeruginosa Biofilms And Persister Cells By Manipulating Cell-Cell Signaling, Shuyuan Ma

Theses - ALL

Bacterial cells often form sessile biofilms that are up to 1,000 times more resistant to antimicrobial agents than free-living cells. Meanwhile, bacteria produce a small subpopulation of slow-growing or non-growing persister cells that exhibit high tolerance to antibiotics. Both biofilms and persister cells play important roles in the recalcitrance of chronic infections. Recent studies have shown that bacterial cell-to-cell communication, named quorum sensing (QS), is involved in the biofilm and persister formation.

In this study, we investigated the effects of quorum sensing signals N-(3-oxododecanoyl)-homoserine lactone (3-oxo-C12-HSL) and N-butyryl homoserine lactone (C4-HSL) on isolated Pseudomonas aeruginosa PAO1 and PDO300 persister cells. …

Tyrosine 370 Phosphorylation Of Atm Positively Regulates Dna Damage Response, Hong-Jen Lee

Dissertations and Theses (Open Access)

Ataxia telangiectasia-mutated (ATM) mediates DNA damage response by controlling irradiation (IR)-induced foci formation, cell cycle checkpoint, and apoptosis. However, how upstream signaling regulates ATM is not completely understood. Here, we show that upon IR stimulation, ATM associates with and is phosphorylated by epidermal growth factor receptor (EGFR) at Y370 at the site of double-strand breaks. Depletion of endogenous EGFR impairs ATM-mediated foci formation, homologous recombination, and DNA repair. Moreover, ATM Y370F mutant or pretreatment with an EGFR kinase inhibitor gefitinib blocks EGFR and ATM association, hinders CHK2 activation and subsequent foci formation, and increases radio-sensitivity. Thus, we reveal a critical …

Roles For B-Raf Kinase In The Specific Regulation Of Α4Β1 Integrin In T Cells, Wells S. Brown

Dissertations and Theses (Open Access)

The regulation of integrin-mediated adhesion is of vital importance to adaptive and innate immunity. Integrins are versatile proteins and mediate T cell migration and trafficking by binding to ECM or other cells, as well as initiating intracellular signaling cascades promoting survival or activation. The mitogen activated-protein kinase (MAPK) pathway is known to be downstream from integrins and regulate survival, differentiation, and motility. However, secondary roles for canonical MAPK pathway members are being discovered. We show chemical inhibition of RAF by Sorafenib or shRNA-mediated knockdown of B-Raf reduces T cell resistance to shear stress to α4β1 integrin ligands vascular cell adhesion …

Egfr Modulates Microrna Maturation In Response To Hypoxia Through Phosphorylation Of Argonaute2, Jia Shen

Dissertations and Theses (Open Access)

MicroRNAs (miRNAs) are generated by two-step processing to yield small RNAs that negatively regulate target gene expression at posttranscriptional level. Deregulation of miRNAs has been linked to diverse pathological processes, including cancer. Recent studies have also implicated miRNAs in regulatory roles to cope with a spectrum of stresses, such as hypoxia, which is frequently encountered in the poorly angiogenic core of a solid tumor. However, the upstream regulators of miRNA biogenesis machineries remain obscure, raising the question of how tumor cells efficiently coordinate and impose specificity on miRNA expression and function in response to stresses. Here, we show that EGFR, …

Brit1/Mcph1 Mediates The Dna Damage Response By Inducing P53 Stability And Promoting Atr Signaling, Edward Wang

Dissertations and Theses (Open Access)

The BRCT-repeat inhibitor of hTERT (BRIT1)/MCPH1 protein promotes the process of homologous recombination (HR) to repair DNA double strand breaks (DSBs). In response to DSBs, BRIT1 foci form at damaged sites, and recruits downstream repair proteins including 53BP1, MDC1, NBS1, and the SWI/SNF complex to the DSB region to promote DNA repair. BRIT1 copy number deficiency correlates with increased genomic instability in ovarian cancer specimens and breast cancer cell lines. Here, we propose that additional functions of BRIT1 include a direct interaction with the p53 tumor suppressor protein to promote p53 stability, and binding and recruitment of TopBP1 to sites …

Nuclear Translocation Of Met Via Internet Mechanism, Mei-Kuang Chen

Dissertations and Theses (Open Access)

MET is one of the receptor tyrosine kinases (RTKs) that are overexpressed in malignant cancer types, including breast cancer. While RTKs are traditionally known for their roles in signaling transduction from the cell surface, recent studies have provided evidence demonstrating that most of RTKs can translocate into nucleus to regulate cellular processes in response to both ligand and stress stimulation. Oxidative stress is a common stress in cancer cells due to alteration of metabolism, and constitutive oxidative stress related to reactive oxygen species (ROS) has been observed in breast cancer cells. Here, we show that hepatocyte growth factor (HGF) as …

Angiomotin Is A Novel Cadherin-11 Interacting Protein That Mediates Migration In Prostate Cancer Cells, Angelica Ortiz

Dissertations and Theses (Open Access)

Prostate cancer (PCa), the second leading cause of cancer-related deaths among men in the United States, has the proclivity to metastasize to bone resulting in sclerotic lesions. These cancer induced bone growths cause bone pain and fractures. Therefore, understanding the molecular mechanisms contributing to PCa bone metastasis is required in order to find better prognostic tools and suitable targets for metastasis treatment and/ or prevention. Previous work in our laboratory showed increased expression of cadherin-11 (Cad11), a mesenchymal cadherin, during PCa progression. Furthermore, Cad11 expression endows PCa cells with increased migratory potential and metastasis to bone. Deletion of the Cad11 …

Energy Stress Causes Chaperones To Assemble Into Cytoplasmic Complexes, Kimberly J. Cope

Dissertations and Theses (Open Access)

The majority of proteins require molecular chaperones to assist their folding into tertiary and quaternary structures. Certain stresses can compromise the weak hydrophobic forces responsible for these structures and lead to protein unfolding, misfolding, and aggregation. Aggregates of proteins are hallmarks of devastating diseases such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. Fortunately, bacteria, plants, and fungi have a potent disaggregase, named Hsp104 in Saccharomyces cerevisiae. Recently, heat-induced aggregates, termed Q-bodies, were found to contain three molecular chaperones: Hsp70, Hsp104, and Hsp42. Their coalescence from small puncta into larger inclusions required Hsp104. During glucose deprivation, a stress that isn’t known to …

Construction Of 3d Biomimetic Tissue Niches For Directing Pancreatic Lineage Differentiation Of Human Embryonic Stem Cells, Weiwei Wang

Graduate Theses and Dissertations

The potential of human embryonic stem cells (hESCs) to differentiate into insulin producing beta cells offers great hope for cell-based therapy for diabetes treatment. However, in vitro pancreatic differentiation of hESCs remains challenging. In the past decade, most protocols for differentiating pancreatic cells have been focused on the use of signaling molecule cocktails on 2D substrates. Studies on embryonic development biology strongly suggest that extracellular matrix (ECM) plays a critical role on hESCs behavior. In this work, we first established a 3D collagen scaffold culture system for hESCs differentiating into definitive endoderm (DE), which is the first and most important …

Role Of Msaa Gene In Regulation Of The Msaabcr Operon And Biofilm Development In Staphylococcus Aureus, Ahmed Alzuway

Master's Theses

Staphylococcus aureus is an important human pathogen that causes wide variety of diseases ranging from chronic biofilm associated infection to acute life threatening infection such as bacteremia, pneumonia, osteomyelitis, or endocarditis, despite the progress with antibiotics used in the treatment of bacterial infections. Furthermore, increased use of prosthetic and indwelling devices in modern medical practices has led to increased infections due to S. aureus. Treating S. aureus infections have become difficult owing to its ability to resist most of the antibiotics; this problem is further exacerbated by ability of MRSA strains to form biofilms. Emergence of community-acquired methicillin resistance …

Identification And Characterization Of Msab Gene Involved In Biofilm Formation And Virulence In Staphylococcus Aureus, Amelsaad Elbarasi

Master's Theses

Staphylococcus aureus is an important human pathogen that causes a wide variety of life-threatening infections ranging from minor skin and oral infections to severe infections, such as bacteremia, pneumonia, osteomyelitis, or endocarditis due to the presence and secretion of a large number of virulence factors that are controlled by global virulence regulators in complex networks. Furthermore, S. aureus infections have become a threat to public health because of their high potential to form biofilm, and their ability to resist a wide range of antibiotics has exacerbated further. Therefore, understanding the regulatory networks and developing a drug targeting these networks has …

Metagenomic Identification Of A Novel Salt Tolerance Gene From The Human Gut Microbiome Which Encodes A Membrane Protein With Homology To A Brp/Blh-Family Beta-Carotene 15,15'-Monooxygenase, Eamonn P. Culligan, Roy D. Sleator, Julian R. Marchesi, Colin Hill

Department of Biological Sciences Publications

The human gut microbiome consists of at least 3 million non-redundant genes, 150 times that of the core human genome. Herein, we report the identification and characterisation of a novel stress tolerance gene from the human gut metagenome. The locus, assigned brpA, encodes a membrane protein with homology to a brp/blh-family β-carotene monooxygenase. Cloning and heterologous expression of brpA in Escherichia coli confers a significant salt tolerance phenotype. Furthermore, when cultured in the presence of exogenous β-carotene, cell pellets adopt a red/orange pigmentation indicating the incorporation of carotenoids in the cell membrane.

Rpl24: A Potential Therapeutic Target Whose Depletion Or Acetylation Inhibits Polysome Assembly And Cancer Cell Growth., Kathleen A. Wilson-Edell, Amanuel Kehasse, Gary K. Scott, Christina Yau, Daniel E. Rothschild, Birgit Schilling, Bianca S Gabriel, Mariya A. Yevtushenko, Ingrid M. Hanson, Jason M. Held, Bradford W. Gibson, Christopher C. Benz

Natural Sciences and Mathematics | Student Professional Publications

Partial loss of large ribosomal subunit protein 24 (RPL24) function is known to protect mice against Akt or Myc-driven cancers, in part via translational inhibition of a subset of cap(eIF4E)-dependently translated mRNAs. The role of RPL24 in human malignancies is unknown. By analyzing a public dataset of matched human breast cancers and normal mammary tissue, we found that breast cancers express significantly more RPL24 than matched normal breast samples. Depletion of RPL24 in breast cancer cells by >70% reduced cell viability by 80% and decreased protein expression of the eIF4E-dependently translated proteins cyclin D1 (75%), survivin (46%) and NBS1 (30%) …