Master of Science in Biomedical Engineering (MSBME), Wright State University, 2020, Biomedical Engineering

High cognitive workload occurs when excessive working memory resources have been deployed to resolve sensory and cognitive processing, resulting in decremented task performance. The P300 event-related potential (ERP) component has shown sensitivity to cognitive load, and it was hypothesized that an attenuated P300 amplitude could be indicative of high cognitive load. We tested this hypothesis by having eight participants complete two continual performance tasks at increasing workload levels while simultaneously performing an oddball task, evoking P300 ERPs in either the auditory or tactile sensory channel. In our experiment, electroencephalographic recordings were collected over the parietal region to observe the P300 component. Our results show a downward trend in P300 amplitude as workload increased when performing auditory oddball tasks, although P300's elicited by the tactile oddball tasks produced no consistent trend. These results suggest cognitive load indexing is possible in select sensory channels, though additional investigation is required.

Committee: Sherif Elbasiouny Ph.D. (Advisor); Ulas Sunar Ph.D. (Committee Member); Matthew Sherwood Ph.D. (Committee Member) Subjects: Biomedical Engineering; Neurosciences

Master of Science, Miami University, 2020, Microbiology

Histone acetyltransferases (HATs) and histone deacetylases (HDACs) are epigenetic and non-epigenetic modifiers that are important for regulating cellular processes. Viruses are able to exploit their activities to benefit the viral life cycle at the expense of the host. Both HATs and HDACs have important roles in cellular proliferation and manipulating these activities has been shown to increase the development of diseases such as cancer. The HAT p300/CBP and the HDAC SIRT7 both target histone 3 lysine 18 (H3K18) and are manipulated by early adenovirus proteins, suggesting that p300/CBP and sirtuin activities are important for viral growth and cellular proliferation. Inhibition of p300/CBP activity did not affect cellular proliferation but delayed the onset of viral DNA replication, while inhibition of the class III HDACs, the sirtuins, had little effect on either viral or cellular DNA replication. We also determined that H3K18 hypoacetylation begins at the onset of viral DNA replication and the HDAC SIRT7 contributes to the H3K18 hypoacetylation. Knowledge gained from this study has the potential to identify possible therapeutic targets to reduce viral infection or limit the development of disease such as cancer.

Committee: Eileen Bridge Dr. (Advisor); Mitchell Balish Dr. (Committee Member); Rebecca Balish Dr. (Committee Member); Joseph Carlin Dr. (Committee Member) Subjects: Molecular Biology; Virology

Doctor of Philosophy, The Ohio State University, 2014, Integrated Biomedical Science Graduate Program

One-third of the world population is infected with Mycobacterium tuberculosis (M.tb), the causative agent of tuberculosis, which leads to 1.3 million deaths annually. M.tb is a host-adapted intracellular pathogen of macrophages. A complex, evolutionally adaptive relationship exists between M.tb and the host during which the pathogen evades and subverts the immune response mounted by the macrophage. Understanding the interactions during primary infection between the macrophage and M.tb are important as they determine outcomes of infection and course of disease. In this dissertation we examined the roles of microRNAs (miRNA) and MAPK pathways in M.tb infection of primary human macrophages and identified two mechanisms through which M.tb can down-regulate macrophage immune responses and promote its intracellular survival. We determined the miRNA expression profile of M.tb-infected monocyte-derived macrophages (MDM) by the NanoString nCounter miRNA Expression Assay and identified a number of miRNAs that were differentially expressed relative to the non-infected controls 24 h and 72 h after M.tb infection. Among the up-regulated macrophage miRNAs at 72 h after M.tb infection were miR-132 and miR-26a, which we show down-regulates expression of the transcriptional activator p300, a component of the IFN-gamma signaling pathway that mediates transcriptional responses to IFN-gamma in macrophages. Our data suggest that during human M.tb infection there is decreased capacity for macrophages to be activated by IFN-gamma and perform microbicidal functions. In addition, we show that the expression of the MAP3K Tpl-2, which was previously identified as a host defense molecule against M.tb in a murine knockout model, is down-regulated during M.tb infection in human primary macrophages. Concurrently, we observed increased mRNA levels of Tpl-2, suggesting a role for miRNAs in targeting Tpl-2 mRNA or other post-translational regulatory mechanisms such as loss of stabilization by (open full item for complete abstract)

Committee: Larry Schlesinger MD (Advisor); Amal Amer MD, PhD (Committee Member); Clay Marsh MD (Committee Member); Stephanie Seveau PhD (Committee Member) Subjects: Immunology; Microbiology

MS, University of Cincinnati, 2012, Engineering and Applied Science: Computer Science

In recent decades, the field of Brain-Computer Interface (BCI) technologies has been vigorously developed by research groups from all over the world. A BCI system can build a directly pathway between the brain and an external device so that patients with impaired motor activities can be assisted with this system to realize the communication with others. Among varieties of BCI systems, P300 speller is one that has been successfully developed with several advantages such as easy to carry on the experiment and the achievement of relatively better accuracy rate. In this thesis a system is designed to improve the current P300 speller performance based on a language prediction model. The method is implemented with MATLAB simulations in the evaluation of both system accuracy and speedup. The result of the conducted experiments shows the feasibility of our proposed system.

Committee: Anca Ralescu PhD (Committee Chair); J. Adam Wilson PhD (Committee Member); Chia Han PhD (Committee Member); Dan Ralescu PhD (Committee Member) Subjects: Computer Science

Doctor of Philosophy, The Ohio State University, 2004, Veterinary Biosciences

Retrovirus-derived vectors provide efficient means of gene-transfer and are potential tools for therapeutic intervention against congenital or inherited disorders by in-utero gene therapy and for gene-transfer into dividing cells both in vitro and in vivo. To improve biodistribution of retroviral gene-transfer vectors and to obtain efficient gene-transfer towards hematopoietic stem cells via pre-natal administration, we performed in-utero administration of retroviral vectors pseudotyped with different envelope glycoproteins. Relatively high gene-transfer was obtained with significant differences in biodistribution and gene-transfer efficiency using various pseudotypes. There was significant reduction in the percentage of colonies containing transgene, 3 months postnatally. Next, we used HIV-derived lentiviral vectors to investigate the role of human T-lymphotropic virus type-1 (HTLV-1) accessory protein p12(I) in viral pathogenesis. HTLV-1, a deltaretrovirus cause adult T-cell leukemia/lymphoma, and other lymphocyte-mediated disorders. HTLV-1 provirus encodes various regulatory and accessory genes, including ORF-I encoded p12(I). We have demonstrated that this endoplasmic reticulum-localizing protein, increases intracellular calcium, activates NFAT-mediated transcription and is critical for infectivity in vivo and in vitro. Herein, using microarrays, we tested the role of p12(I) in regulating cellular gene expression in T-lymphocytes and found that p12(I) altered the expression of several calcium-regulated genes and genes associated with T-cell signaling, cell-proliferation and apoptosis. Furthermore, p12(I) upregulated the levels of p300 to transcriptionally significant levels, in T-lymphocytes. Next, we further characterized the mechanism of p300 upregulation by p12(I) and demonstrate that it is calcium-dependent, but calcineurin-independent. Sustained low-magnitude calcium release results in increased p300 RNA, protein and p300-mediated transcriptional activity i (open full item for complete abstract)

Committee: Michael Lairmore (Advisor) Subjects: Biology, Molecular

Doctor of Philosophy, The Ohio State University, 2004, Veterinary Biosciences

Human T-lymphotropic virus type-1 (HTLV-1), a deltaretrovirus cause adult T-cell leukemia/lymphoma and other lymphocyte-mediated disorders. HTLV-1 provirus encodes various regulatory and accessory genes, including p30(II). Our laboratory has identified the functional properties of pX ORF-II encoded p30(II), but the role of this viral protein in virus replication or pathogenesis remains unclear. We have reported that HTLV-1 p30(II), a nuclear-localizing protein, interacts with CBP/p300, disrupts CREB-Tax-CBP/p300 complex formation at HTLV-1 Tax-Responsive Elements repeats (TRE) and differentially modulates CREB and TRE-mediated transcription. We have also recently demonstrated that p30(II) is critical in maintaining viral loads in vivo. Herein, we further characterized the role of p30(II) in regulation of cellular gene expression, using microarrays and identified alterations of interrelated pathways of cell-proliferation, T-cell signaling, apoptosis and cell-cycle in p30(II)-expressing T-lymphocytes. We are the first to test the overall effect of an HTLV-1 accessory protein, on cellular gene expression and demonstrate that p30(II) activates transcription factors involved in T-cell signaling/activation, such as NFAT, NF-KB and AP-1. We further characterized the role of p30(II) in regulation of viral gene expression, by identifying motifs critical in binding p300 and regulating TRE-mediated transcription. By analysing the amino acid domain of p30(II) critical for repressing LTR-mediated transcription, we identified a lysine residue at amino acid 106 of p30(II), that is critical for repressing TRE-mediated transcription. Additionally, we found that p300 reverses p30(II)-dependent repression of TRE-mediated transcription, in a dose-responsive manner. Our data confirms the role of p30(II) as a regulator of viral gene transcription, in association with p300. However, unlike wildtype p300, p300 HAT mutants only partially rescue p30(II)-mediated LTR repression. Additionally, (open full item for complete abstract)

Committee: Michael Lairmore (Advisor) Subjects: Biology, Molecular

Master of Arts, Miami University, 2008, Speech Pathology and Audiology

Over 800 athletes suffer from concussion in the United States each day, resulting in over 300,000 concussions each year. Recent data has revealed that the incidence of mild traumatic brain injury is on the rise for many different sports, placing athletes at higher risk. Damage is caused by the shearing of axons, which results in swelling and loss of limited function. Electrophysiologic techniques, specifically event-related potentials are one of the most frequently used cognitive assessments. Event-related potentials are a non-invasive method to gather a baseline of cognitive processes and to evaluate cognitive deficits. The current study investigated the sensitivity of event-related potentials in the identification of cognitive deficits following concussion in college athletes. Neuropsychological and electrophysiological measures were collected from two groups of participants allocated by injury versus non-injury. Results from the study found important differences between non-concussed and concussed athletes using electrophysiological measures and neuropsychological test measures.

Committee: Kathleen Hutchinson PhD (Committee Chair); Fofi Constantinidou PhD (Committee Member); J Brett Massie EdD (Committee Member) Subjects: Cognitive Therapy; Communication; Speech Therapy; Sports Medicine

Doctor of Philosophy, Case Western Reserve University, 2008, Neurosciences

Apolipoprotein E (ApoE) is associated with age-related risk for Alzheimer's disease and plays critical roles in Aβ metabolism. ApoE is the major apolipoprotein present in high-density lipoproteins (HDL) and plays an essential role in cholesterol homeostasis in the brain. The ATP-binding cassette A1 (ABCA1) mediates the efflux of cholesterol and phospholipids into ApoE HDL. Liver X receptors regulate the expression of ApoE and ABCA1. ApoE plays a previously unappreciated role in facilitating the proteolytic clearance of soluble Aβ from the brain. The endolytic degradation of Aβ peptides within microglia by neprilysin and related enzymes is dramatically enhanced by ApoE. Similarly, Aβ degradation extracellularly by insulin degrading enzyme is facilitated by ApoE. The capacity of ApoE to promote Aβ degradation is dependent upon the ApoE isoform and its lipidation status. The enhanced expression of lipidated ApoE, through the activation of liver X receptors, stimulates Aβ degradation. In vivo, aged Tg2576 mice treated with the LXR agonist GW3965 exhibited a dramatic reduction in brain Aβ load. Significantly, GW3965 treatment also reversed contextual memory deficits. In N2a.Swe cells, LXR activation induced ABCA1 expression and reduced steady state Aβ levels. However, it did not affect the levels of holo-APP, the generation of secreted α-APP or C-terminal fragment. LXR did not affect the distribution of APP or its processing machinery, supporting the conclusion that LXR-mediated reduction of Aβ is due to enhanced clearance but not altered APP processing. Amyloid plaques are associated with a chronic inflammatory environment. LXR activation inhibited microglia-mediated inflammation both in vitro and in vivo. This inhibition is due to its regulation of NFκB transcriptional activity by actively stimulating the nuclear export of p65. The effect of the LXR agonist on p65 nuclear export correlates with its effect on the dynamic exchange of the SMRT/HDAC3 corepressor complex fo (open full item for complete abstract)

Committee: Gary Landreth PhD (Advisor); Evan Deneris PhD (Committee Chair); Bruce Lamb PhD (Committee Member); Hung-ying Kao PhD (Committee Member) Subjects: Biomedical Research

Doctor of Philosophy, Case Western Reserve University, 2008, Biochemistry

AP-1 complexes are a family of transcription factors ubiquitously expressed in different cell types. Transcriptional regulation mediated by AP-1 has been extensively studied; AP-1 mainly works through its cognate sequences, which are found in the regulatory elements in a variety of genes. Current genome-wide promoter occupancy studies indicate that the regulatory specificity is conferred mainly through combinatorial transcription factor binding elements containing non-consensus low affinity sites. However, the question of whether the binding sequences possess intrinsic selectivity for a given family transcription factors, which exhibit overlapping binding preference, is hard to define in living cells. Our in vitro biochemical studies unambiguously demonstrated that distinct AP-1 sites, derived from the HPV-11 upstream regulatory region (URR), indeed exhibit differential binding properties toward distinct recombinant human AP-1 complexes. Importantly, we further disclosed a conserved consensus-like binding site existing near the E6 core promoter across different genital HPVs based on an in-depth analysis of our in vitro experimental data. It is noteworthy that the investigation of AP-1-mediated regulation of HPV chromatin transcription is significantly facilitated by the strategy of in vivo reconstitution of coexpressed human AP-1 subunits using a polycistronic bacterial expression system to generate various full-length recombinant AP-1 complexes, which were applied to various in vitro functional assays performed in the present work. Previously we found that both AP-1 and p300 are required for activation of HPV chromatin transcription; however, the underlying mechanism remains unclear. We demonstrated that AP-1 recruits p300 to stimulate in vitro HPV chromatin transcription mainly depends on acetylation of nucleosomal histones by p300. Interestingly, p300 can also mediate acetylation of all the subunits of AP-1 complexes, whose DNA binding activity is stimulated by a (open full item for complete abstract)

Committee: Cheng-Ming Chiang (Advisor) Subjects:

Doctor of Philosophy, Case Western Reserve University, 2006, Pharmacology

Cited2 [CBP/p300 interacting transactivator with E (Glutamic acid) and D (Aspartic acid) rich C-terminal domain, 2] is a CBP/p300 binding transcription factor without typical DNA binding domains. Cited2 interacts with LIM-homeobox gene 2 (Lhx2), Transcription factor AP2 (TFAP2), and nuclear receptors to function as a transcriptional co-activator. Cited2 is implicated in the control of cell growth and malignant transformation in Rat1 cells. Cited1 enhances Smad mediated transcription, suggesting that members of the Cited family may function as a co-activator in transforming growth factor-beta (TGF-beta) signaling. We have explored the function of Cited2 in the TGF-beta signaling pathway. In promoter reporter assays, Cited2 enhances Smad3 mediated transcription. This may occur through a direct physical association of Cited2 with Smads 2/3 and p300. We found that Cited2 modulates TGF-beta mediated upregulation of Matrix Metalloproteinase 9 (MMP9). In chromatin immunoprecipitation experiment, Cited2 and Smad3 are recruited to MMP9 promoter upon TGF-beta stimulation. Knockdown of Cited2 in MDA-MB-231 cells attenuates TGF-beta mediated cell migration, suggesting that Cited2 could play a role during tumor progression. Cited2 is downregulated by TGF-beta in MDA-MB-231 cells. We show that Smad2/3/4 and p38MAPK pathways are involved in TGF-beta mediated downregulation of Cited2. Nuclear run-on analysis and Cited2 promoter/reporter assays demonstrate that downregulation of Cited2 by TGF-beta is through posttranscriptional regulation. In transcriptional inhibitor assays, Cited2 mRNA turnover is increased under TGF-beta stimulation. We examined the expression of recombinant Cited2 gene introduced into MDA-MB-231 cells by stable transfection, and found that mRNA containing the Cited2 protein-coding region controlled by a heterologous promoter indeed responds to TGF-beta mediated downregulation. Our findings support that TGF-beta mediated downregulation of Cited2 is under posttran (open full item for complete abstract)

Committee: Yu-Chung Yang (Advisor) Subjects: Biology, Molecular