Biochemistry, Biophysics, and Structural Biology Commons^™

Downregulation Of Fkbp5 Promotes Atrial Arrhythmogenesis, Xiaolei Wang, Jia Song, Yue Yuan, Luge Li, Issam Abu-Taha, Jordi Heijman, Liang Sun, Shokoufeh Dobrev, Markus Kamler, Liang Xie, Xander H T Wehrens, Frank T Horrigan, Dobromir Dobrev, Na Li

Faculty, Staff and Students Publications

BACKGROUND: Atrial fibrillation (AF), the most common arrhythmia, is associated with the downregulation of

METHODS: Right atrial samples from patients with AF were used to assess the protein levels of FKBP5. A cardiomyocyte-specific FKBP5 knockdown mouse model was established by crossbreeding

RESULTS: FKBP5 protein levels were lower in the atrial lysates of patients with paroxysmal AF or long-lasting persistent (chronic) AF. Cardiomyocyte-specific knockdown mice exhibited increased AF inducibility and duration compared with control mice. Enhanced AF susceptibility in cardiomyocyte-specific knockdown mice was associated with the development of action potential alternans and spontaneous Ca

CONCLUSIONS: This is the first study to …

An Improved Reporter Identifies Ruxolitinib As A Potent And Cardioprotective Camkii Inhibitor, Oscar E Reyes Gaido, Nikoleta Pavlaki, Jonathan M Granger, Olurotimi O Mesubi, Bian Liu, Brian L Lin, Alan Long, David Walker, Joshua Mayourian, Kate L Schole, Chantelle E Terrillion, Lubika J Nkashama, Mohit M Hulsurkar, Lauren E Dorn, Kimberly M Ferrero, Richard L Huganir, Frank U Müller, Xander H T Wehrens, Jun O Liu, Elizabeth D Luczak, Vassilios J Bezzerides, Mark E Anderson

Faculty, Staff and Students Publications

Ca2+/calmodulin-dependent protein kinase II (CaMKII) hyperactivity causes cardiac arrhythmias, a major source of morbidity and mortality worldwide. Despite proven benefits of CaMKII inhibition in numerous preclinical models of heart disease, translation of CaMKII antagonists into humans has been stymied by low potency, toxicity, and an enduring concern for adverse effects on cognition due to an established role of CaMKII in learning and memory. To address these challenges, we asked whether any clinically approved drugs, developed for other purposes, were potent CaMKII inhibitors. For this, we engineered an improved fluorescent reporter, CaMKAR (CaMKII activity reporter), which features superior sensitivity, kinetics, and …

Ngr1 Binding To Reovirus Reveals An Unusual Bivalent Interaction And A New Viral Attachment Protein, Danica M Sutherland, Michael Strebl, Melanie Koehler, Olivia L Welsh, Xinzhe Yu, Liya Hu, Rita Dos Santos Natividade, Jonathan J Knowlton, Gwen M Taylor, Rodolfo A Moreno, Patrick Wörz, Zachery R Lonergan, Pavithra Aravamudhan, Camila Guzman-Cardozo, Sukhleen Kour, Udai Bhan Pandey, David Alsteens, Zhao Wang, B V Venkataram Prasad, Thilo Stehle, Terence S Dermody

Faculty, Staff and Students Publications

Nogo-66 receptor 1 (NgR1) binds a variety of structurally dissimilar ligands in the adult central nervous system to inhibit axon extension. Disruption of ligand binding to NgR1 and subsequent signaling can improve neuron outgrowth, making NgR1 an important therapeutic target for diverse neurological conditions such as spinal crush injuries and Alzheimer's disease. Human NgR1 serves as a receptor for mammalian orthoreovirus (reovirus), but the mechanism of virus-receptor engagement is unknown. To elucidate how NgR1 mediates cell binding and entry of reovirus, we defined the affinity of interaction between virus and receptor, determined the structure of the virus-receptor complex, and identified …

Obstructive Sleep Apnea-Induced Hypertension Is Associated With Increased Gut And Neuroinflammation, Sriram Ayyaswamy, Huanan Shi, Bojun Zhang, Robert M Bryan, David J Durgan

Faculty, Staff and Students Publications

Background

Obstructive sleep apnea (OSA) is an independent risk factor for the development of hypertension. We have demonstrated that OSA induces gut dysbiosis, and this dysbiotic microbiota contributes to hypertension. However, the mechanisms linking gut dysbiosis to blood pressure regulation remain unclear. Recent studies demonstrate that gut dysbiosis can induce a proinflammatory response of the host resulting in peripheral and neuroinflammation, key factors in the development of hypertension. We hypothesized that OSA induces inflammation in the gut that contributes to neuroinflammation and hypertension.

Methods and Results

OSA was induced in 8‐week‐old male rats. After 2 weeks of apneas, lymphocytes were …

Anti-Pancreatic Cancer Activity Of Rhus Coriaria (Sumac), Yassine Elmahi

Theses

Cancer is a major health problem and is considered a chronic disease globally. Pancreatic cancer is one of the deadliest types of cancer. That is because symptoms increase until the cancer is spread to other parts of the body in late stages. Among the many different therapeutic approaches to treat cancer, it appears that many plants have promising treatment effects, and one of these plants is Rhus coriaria, commonly known as Sumac. Previous studies have indicated that the Sumac plant, which is used in cooking, possesses various therapeutic values, including antioxidant and antibiotic activities. This study investigates the effect …

Molecular Mechanisms Of Natural And Synthetic Compounds Against Breast And Colon Cancer, Aysha Hamad Alneyadi

Dissertations

Cancer is a complex disease with various causes, including genetic mutations, viruses, chemical agents, and lifestyle factors. Although numerous studies have been conducted to develop a cure or novel medications for cancer, no standout treatment has been found. In this project, the use of various natural and synthetic compounds as potential cancer treatments was investigated using triple-negative breast cancer (TNBC) and colon cancer cells. The cancer therapy strategies investigated were based on plant-derived therapuetic approaches including an essential oil (Origanum majorana essential oil), a pure phytochemical (Carnosol), and newly developed synthetic drugs (Chromenes drevatives; C1 and C2). This study …

Understanding The Intracellular Positive Regulatory Interactions In The Metabolic Network, Sultana Mohammed Al Zubaidi

Theses

Metabolism is an essential cellular process that produces essential components such as energy molecules and cellular building blocks. It is regulated by intracellular metabolite-enzyme interactions, which can increase or decrease enzyme efficiency. Each metabolic process is not evolved in nature and may not contribute to the optimal efficiency of the organism's metabolism. However, this study aims to clarify the relationship between cellular positive regulatory interactions and the cell's metabolic network, especially how these relationships regulate metabolism and how it evolved in nature. To obtain that, for each enzyme, the activation molecules from the BRENDA database were downloaded, mapped data to …

Metals And Metal Complexes In Diseases With A Focus On Covid-19: Facts And Opinions, Agnieszka Ścibior, Manuel Aureliano, Alvin A. Holder, Juan Llopis

Chemistry & Biochemistry Faculty Publications

In the present Special Issue on “Metals and Metal Complexes in Diseases with a Focus on COVID-19: Facts and Opinions”, an attempt has been made to include reports updating our knowledge of elements considered to be potential candidates for therapeutic applications and certain metal-containing species, which are extensively being examined towards their potential biomedical use due to their specific physicochemical properties. The Special Issue compiles data on the role of metals in COVID-19 and focuses on other illnesses and biological processes that affect metal metabolism. It consists of eight manuscripts, including five review articles and three original research papers (Figure …

Extraction Of Challenging Forensic Samples Using The Microgem Dna Extraction Kit, Falyn R. Vega

Student Theses

In forensic science, DNA extraction can be a tedious and resource-intensive process. Extraction with Proteinase K is an industry standard but has its drawbacks, such as requiring multiple ionic detergents and washing steps. MicroGEM has developed a new enzyme called forensicGEM that is temperature-dependent and compatible with mesophilic enzymes, offering complete DNA extraction in about 20 minutes in a single tube, limiting contamination, loss of sample, and working time. ForensicGEM can extract DNA from highly degraded samples, potentially leading to more complete STR profiles. Highly degraded tissue and bone samples were collected and extracted with the forensicGEM …

Mouse Models Of Spontaneous Atrial Fibrillation, Joshua A Keefe, Mohit M Hulsurkar, Svetlana Reilly, Xander H T Wehrens

Faculty, Staff and Students Publications

Atrial fibrillation (AF) is the most common arrhythmia in adults, with a prevalence increasing with age. Current clinical management of AF is focused on tertiary prevention (i.e., treating the symptoms and sequelae) rather than addressing the underlying molecular pathophysiology. Robust animal models of AF, particularly those that do not require supraphysiologic stimuli to induce AF (i.e., showing spontaneous AF), enable studies that can uncover the underlying mechanisms of AF. Several mouse models of AF have been described to exhibit spontaneous AF, but pathophysiologic drivers of AF differ among models. Here, we describe relevant AF mechanisms and provide an overview of …

Comprehensive Ecg Reference Intervals In C57bl/6n Substrains Provide A Generalizable Guide For Cardiac Electrophysiology Studies In Mice, Manuela A Oestereicher, Janine M Wotton, Shinya Ayabe, Ghina Bou About, Tsz Kwan Cheng, Jae-Hoon Choi, Dave Clary, Emily M Dew, Lahcen Elfertak, Alain Guimond, Hamed Haseli Mashhadi, Jason D Heaney, Lois Kelsey, Piia Keskivali-Bond, Federico Lopez Gomez, Susan Marschall, Michael Mcfarland, Hamid Meziane, Violeta Munoz Fuentes, Ki-Hoan Nam, Zuzana Nichtová, Dale Pimm, Lynette Bower, Jan Prochazka, Jan Rozman, Luis Santos, Michelle Stewart, Nobuhiko Tanaka, Christopher S Ward, Amelia M E Willett, Robert Wilson, Robert E Braun, Mary E Dickinson, Ann M Flenniken, Yann Herault, K C Kent Lloyd, Ann-Marie Mallon, Colin Mckerlie, Stephen A Murray, Lauryl M J Nutter, Radislav Sedlacek, Je Kyung Seong, Tania Sorg, Masaru Tamura, Sara Wells, Elida Schneltzer, Helmut Fuchs, Valerie Gailus-Durner, Martin Hrabe De Angelis, Jacqueline K White, Nadine Spielmann

Faculty, Staff and Students Publications

Reference ranges provide a powerful tool for diagnostic decision-making in clinical medicine and are enormously valuable for understanding normality in pre-clinical scientific research that uses in vivo models. As yet, there are no published reference ranges for electrocardiography (ECG) in the laboratory mouse. The first mouse-specific reference ranges for the assessment of electrical conduction are reported herein generated from an ECG dataset of unprecedented scale. International Mouse Phenotyping Consortium data from over 26,000 conscious or anesthetized C57BL/6N wildtype control mice were stratified by sex and age to develop robust ECG reference ranges. Interesting findings include that heart rate and key …

Magnesium Increases Numbers Of Foxp3+ Treg Cells And Reduces Arthritis Severity And Joint Damage In An Il-10-Dependent Manner Mediated By The Intestinal Microbiome, Teresina Laragione, Carolyn Harris, Nasim Azizgolshani, Christine Beeton, Gerold Bongers, Percio S Gulko

Faculty, Staff and Students Publications

BACKGROUND: Rheumatoid arthritis (RA) is a common autoimmune disease with emerging environmental and microbiome risk factors. The western diet is typically deficient in magnesium (Mg), and there is some evidence suggesting that Mg may have anti-inflammatory properties. But the actual role of Mg supplementation in arthritis or in T cell subsets has not been explored.

METHODS: We investigated the role of a high Mg diet in two different mouse models of RA induced with the KRN serum, and collagen-induced arthritis. We also characterized the phenotypes of splenocytes, gene expression, and an extensive intestinal microbiome analyses including fecal material transplantation (FMT). …

Three-Dimensional Microct Imaging Of Mouse Heart Development From Early Post-Implantation To Late Fetal Stages, Nanbing Li-Villarreal, Tara L Rasmussen, Audrey E Christiansen, Mary E Dickinson, Chih-Wei Hsu

Faculty, Staff and Students Publications

Comprehensive detailed characterization of new mouse models can be challenging due to the individual focus involved in developing these models. Often models are engineered to test a specific hypothesis in a limited number of tissues, stages, and/or other contexts. Whether or not the model produces the desired phenotypes, phenotyping beyond the desired context can be extremely work intensive and these studies are often not undertaken. However, the general information resulting from broader phenotyping can be invaluable to the wider scientific community. The International Mouse Phenotyping Consortium (IMPC) and its subsidiaries, like the Knockout Mouse Project (KOMP), has made great strides …

A Short-Term Method To Evaluate Anti-Leishmania Drugs By Inhibition Of Stage Differentiation In Leishmania Mexicana Using Flow Cytometry, Christian Florian Teh-Poot, Victor Manuel Dzul-Huchim, Jonathan M Mercado, Liliana Estefanía Villanueva-Lizama, Maria Elena Bottazzi, Kathryn M Jones, Francis T F Tsai, Julio Vladimir Cruz-Chan

Faculty, Staff and Students Publications

Leishmaniasis is a vector-borne neglected tropical disease caused by the Leishmania spp. Parasite. The disease is transmitted to humans and animals by the bite of infected female sandflies during the ingestion of bloodmeal. Because current drug treatments induce toxicity and parasite resistance, there is an urgent need to evaluate new drugs. Most therapeutics target the differentiation of promastigotes to amastigotes, which is necessary to maintain Leishmania infection. However, in vitro assays are laborious, time-consuming, and depend on the experience of the technician. In this study, we aimed to establish a short-term method to assess the differentiation status of Leishmania mexicana …

Long Non-Coding Rnas: Definitions, Functions, Challenges And Recommendations, John S Mattick, Paulo P Amaral, Piero Carninci, Susan Carpenter, Howard Y Chang, Ling-Ling Chen, Runsheng Chen, Caroline Dean, Marcel E Dinger, Katherine A Fitzgerald, Thomas R Gingeras, Mitchell Guttman, Tetsuro Hirose, Maite Huarte, Rory Johnson, Chandrasekhar Kanduri, Philipp Kapranov, Jeanne B Lawrence, Jeannie T Lee, Joshua T Mendell, Timothy R Mercer, Kathryn J Moore, Shinichi Nakagawa, John L Rinn, David L Spector, Igor Ulitsky, Yue Wan, Jeremy E Wilusz, Mian Wu

Faculty, Staff and Students Publications

Genes specifying long non-coding RNAs (lncRNAs) occupy a large fraction of the genomes of complex organisms. The term 'lncRNAs' encompasses RNA polymerase I (Pol I), Pol II and Pol III transcribed RNAs, and RNAs from processed introns. The various functions of lncRNAs and their many isoforms and interleaved relationships with other genes make lncRNA classification and annotation difficult. Most lncRNAs evolve more rapidly than protein-coding sequences, are cell type specific and regulate many aspects of cell differentiation and development and other physiological processes. Many lncRNAs associate with chromatin-modifying complexes, are transcribed from enhancers and nucleate phase separation of nuclear condensates …

Ethical Issues And Standards Of Responsible Research Conduct And Monitoring In An Adventist Institution Of Higher Learning - The Babcock Experience, Kayode O. Ogunwenmo, Godswill N. Anyasor, Grace O. Tayo

Adventist Human-Subject Researchers Association

Ethical issues and standards of responsible research conduct involving human participants are important considerations in any institution of higher learning and in particular Adventist institutions. Research conduct and ethics are reviewed and approved before they begin by the Babcock University Health Research Ethics Committee (BUHREC)

Investigating The Role Of Tgf-Beta Signaling In Acoel Regeneration & Fission, Franchesca A. Aziz

Undergraduate Honors Theses

Whole-body regeneration and asexual reproduction are widespread in the Metazoa, yet little is known about the genetic systems that drive the regeneration process outside of a few model organisms. While many animals utilize fission followed by regeneration to accomplish asexual reproduction, Convolutriloba longifissura is unusual in performing a double fission, requiring significant anterior-posterior and medial-lateral regeneration that alters the orthogonal body axes in adult tissues. To better understand the process of axial re-specification during postembryonic development, we studied the genetic mechanisms used by C. longifissura to modify and respecify axial polarity during asexual reproduction and subsequent regeneration. Because conserved signaling …

Cardiac Pericytes Mediate The Remodeling Response To Myocardial Infarction, Pearl Quijada, Shuin Park, Peng Zhao, Kamal Ss Kolluri, David Wong, Kevin D Shih, Kai Fang, Arash Pezhouman, Lingjun Wang, Ali Daraei, Matthew D Tran, Elle M Rathbun, Kimberly N Burgos Villar, Maria L Garcia-Hernandez, Thanh Td Pham, Charles J Lowenstein, M Luisa Iruela-Arispe, S Thomas Carmichael, Eric M Small, Reza Ardehali

Faculty, Staff and Students Publications

Despite the prevalence of pericytes in the microvasculature of the heart, their role during ischemia-induced remodeling remains unclear. We used multiple lineage-tracing mouse models and found that pericytes migrated to the injury site and expressed profibrotic genes, coinciding with increased vessel leakage after myocardial infarction (MI). Single-cell RNA-Seq of cardiac pericytes at various time points after MI revealed the temporally regulated induction of genes related to vascular permeability, extracellular matrix production, basement membrane degradation, and TGF-β signaling. Deleting TGF-β receptor 1 in chondroitin sulfate proteoglycan 4-expressing (Cspg4-expressing) cells reduced fibrosis following MI, leading to a transient improvement in the cardiac …

Structure Of A Eukaryotic Cholinephosphotransferase-1 Reveals Mechanisms Of Substrate Recognition And Catalysis, Lie Wang, Ming Zhou

Faculty, Staff and Students Publications

Phosphatidylcholine (PC) is the most abundant phospholipid in eukaryotic cell membranes. In eukaryotes, two highly homologous enzymes, cholinephosphotransferase-1 (CHPT1) and choline/ethanolamine phosphotransferase-1 (CEPT1) catalyze the final step of de novo PC synthesis. CHPT1/CEPT1 joins two substrates, cytidine diphosphate-choline (CDP-choline) and diacylglycerol (DAG), to produce PC, and Mg2+ is required for the reaction. However, mechanisms of substrate recognition and catalysis remain unresolved. Here we report structures of a CHPT1 from Xenopus laevis (xlCHPT1) determined by cryo-electron microscopy to an overall resolution of ~3.2 Å. xlCHPT1 forms a homodimer, and each protomer has 10 transmembrane helices (TMs). The first 6 TMs carve …

Exrna-Eclip Intersection Analysis Reveals A Map Of Extracellular Rna Binding Proteins And Associated Rnas Across Major Human Biofluids And Carriers, Emily L Laplante, Alessandra Stürchler, Robert Fullem, David Chen, Anne C Starner, Emmanuel Esquivel, Eric Alsop, Andrew R Jackson, Ionita Ghiran, Getulio Pereira, Joel Rozowsky, Justin Chang, Mark B Gerstein, Roger P Alexander, Matthew E Roth, Jeffrey L Franklin, Robert J Coffey, Robert L Raffai, Isabelle M Mansuy, Stavros Stavrakis, Andrew J Demello, Louise C Laurent, Yi-Ting Wang, Chia-Feng Tsai, Tao Liu, Jennifer Jones, Kendall Van Keuren-Jensen, Eric Van Nostrand, Bogdan Mateescu, Aleksandar Milosavljevic

Faculty, Staff and Students Publications

Although the role of RNA binding proteins (RBPs) in extracellular RNA (exRNA) biology is well established, their exRNA cargo and distribution across biofluids are largely unknown. To address this gap, we extend the exRNA Atlas resource by mapping exRNAs carried by extracellular RBPs (exRBPs). This map was developed through an integrative analysis of ENCODE enhanced crosslinking and immunoprecipitation (eCLIP) data (150 RBPs) and human exRNA profiles (6,930 samples). Computational analysis and experimental validation identified exRBPs in plasma, serum, saliva, urine, cerebrospinal fluid, and cell-culture-conditioned medium. exRBPs carry exRNA transcripts from small non-coding RNA biotypes, including microRNA (miRNA), piRNA, tRNA, small …

Sensor-Controlled Digital Game For Heart Failure Self-Management: Protocol For A Randomized Controlled Trial, Kavita Radhakrishnan, Christine Julien, Matthew O'Hair, Rachel Tunis, Grace Lee, Angelica Rangel, James Custer, Tom Baranowski, Paul J Rathouz, Miyong T Kim

Faculty, Staff and Students Publications

BACKGROUND: Heart failure (HF) is the leading cause of hospitalization among older adults in the United States. There are substantial racial and geographic disparities in HF outcomes, with patients living in southern US states having a mortality rate 69% higher than the national average. Self-management behaviors, particularly daily weight monitoring and physical activity, are extremely important in improving HF outcomes; however, patients typically have particularly low adherence to these behaviors. With the rise of digital technologies to improve health outcomes and motivate health behaviors, sensor-controlled digital games (SCDGs) have become a promising approach. SCDGs, which leverage sensor-connected technologies, offer the …

Dna Supercoiling-Induced Shapes Alter Minicircle Hydrodynamic Properties, Radost Waszkiewicz, Maduni Ranasinghe, Jonathan M Fogg, Daniel J Catanese, Maria L Ekiel-Jeżewska, Maciej Lisicki, Borries Demeler, Lynn Zechiedrich, Piotr Szymczak

Faculty, Staff and Students Publications

DNA in cells is organized in negatively supercoiled loops. The resulting torsional and bending strain allows DNA to adopt a surprisingly wide variety of 3-D shapes. This interplay between negative supercoiling, looping, and shape influences how DNA is stored, replicated, transcribed, repaired, and likely every other aspect of DNA activity. To understand the consequences of negative supercoiling and curvature on the hydrodynamic properties of DNA, we submitted 336 bp and 672 bp DNA minicircles to analytical ultracentrifugation (AUC). We found that the diffusion coefficient, sedimentation coefficient, and the DNA hydrodynamic radius strongly depended on circularity, loop length, and degree of …

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield

Honors Scholar Theses

Antibiotic treatment failure is a public health crisis, with a 2019 report stating that roughly 35,000 deaths occur in the United States yearly due to bacterial infections that are unresponsive to antibiotics (1). One complication in the treatment of bacterial infection is antibiotic persistence which further compromises our battle to effectively treat infection. Bacterial persisters can exist in clonal bacterial cultures and can tolerate antibiotic treatment by undergoing reversible phenotypic changes. They can survive drug concentrations that their genetically identical kin cannot. Some persisters remain in a slow growing state and are difficult to target with current antibiotics. A specific …

Is Vdac1 A Novel Bcl2 Family Member That Binds Bax?, Claire Pearson

Honors Theses

Apoptosis is a type of regulated cell death important for normal embryonic development and maintenance of adult tissues by removing excess or dysfunctional cells to ensure proper functioning of organs. The Bcl-2 family of proteins determines whether apoptosis remains suppressed or becomes activated through the balance of interactions among pro-survival and pro-death members. A defining feature of the Bcl-2 family is a BH3 domain that drives interactions between the family members. Isoform 1 of the voltage dependent anion channel (VDAC1) has an important role in metabolism, but was recently found to have high homology with known BH3 domains. This study …

Examining Transcriptional Regulators During Muscle Development In Drosophila Melanogaster, Chaamy Yapa

Student Theses and Dissertations

In Drosophila melanogaster embryos, a distinct approach to study the transcriptional regulation is to examine the larval somatic muscle development. Transcription factors are essential regulatory proteins that help to control gene expression and respond to signaling pathways and various cues. Today, there are at least twenty transcription factors that have been discovered to contribute to the development of the 30 distinct larval somatic muscles in each abdominal hemisegment of Drosophila melanogaster. Several studies have already been conducted on muscle regulatory transcription factors including midline and apterous. These transcription factors were shown to control the development of muscles through mutant …

College Of Natural Sciences Newsletter, March - May 2023, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 4, Issue 2

Page 1 Dean's Message
Page 2-7 Awards and Recognition
Page 8 March 3rd Corothers Seminar
Page 9 54th Geography Convention
Page 10 Spring 2023 Day of Scholars
Page 11 2023 URSCAD Snaps
Page 12-14 Media Coverage of CNS
Page 15 Open PRAIRIE Data

Carbon Quantum Dots' Effects On The Structure And Function Of Neurodegenerative And Non-Neurodegenerative Associated Proteins, Shima Masoudi Asil

Open Access Theses & Dissertations

Protein folding is an important physical process in which the sequences of polypeptides fold into a three-dimensional biological active structure. Misfolding is the conversion of a protein molecule into a structure unlike the native form, and therefore misfolded proteins have a strong tendency to aggregate and make fibrils. Amyloid aggregation is constituted by misfolded amyloidogenic proteins. Neurodegenerative diseases, such as Alzheimer’s Disease (AD), stem from the abnormal accumulation of harmful proteins, including Amyloid-ß peptides, tau protein, and the presynaptic protein α-synuclein in the nervous system. Alzheimer's disease is the most common neurodegenerative disorder that causes memory and learning deficits and …

Nanosecond Pulsed Electric Field Modulates Electron Transport And Mitochondrial Structure And Function, Lucas Nelson Potter

Biomedical Engineering Theses & Dissertations

Pulsed power treatment has been used to induce regulated cell death (RCD) in cells or ablate tumors in animals. A subset of pulsed power as electroporation with high voltage and pulse duration of milliseconds is used for biomedical treatment to induce pores in the plasma membrane of cells. Nanosecond Pulsed Electric Fields (nsPEFs)– an extension of electroporation, uses waveforms with pulse durations on the order of 10-900 nanoseconds. nsPEF treatment has demonstrated intracellular effects for potential biomedical applications. In this work, nsPEF treatment is used to demonstrate changes that affect viability, plasma membrane permeability ROS (Reactive Oxygen Species) in the …

Long-Range Regulation By The Shigella Virulence Gene Regulator, Virb, Cody Cris

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nucleoid-structuring proteins (NSPs) in bacterial cells can exert gene regulatory effects over great distances on DNA. This contrasts with the traditional view of bacterial transcriptional regulation, where transcription factors bind cis-acting regulatory sites proximal (<250 bp) to promoters to influence gene expression. In Shigella species, the histone-like nucleoid-structuring protein (H-NS) transcriptionally silences many genes on the large (~220 kb) virulence plasmid. During host colonization, however, silencing by H-NS is alleviated by the anti-silencer protein, VirB, which remodels the H-NS:DNA complex. This transcriptional anti-silencing is mediated by VirB:DNA interactions and the modulation of DNA supercoiling, which lead to the up-regulation of virulence genes. VirB is a central regulator of Shigella virulence, but the mechanistic basis for transcriptional regulation is incompletely characterized. Here, I focus on the potential for VirB to regulate transcription from remotely located DNA binding sites. Employing complementary in vivo approaches, I assessed the spatial stringency of the VirB binding site and elucidated how varying cellular VirB levels impacts regulation over different distances. I also evaluated how a molecular roadblock on DNA influences remote regulation by VirB. Additionally, I developed control tools to validate the ability of VirB to spread along DNA, an activity of VirB that putatively drives transcriptional regulation. These data are consistent with transcriptional anti-silencing being driven by VirB spreading along DNA. Overall, these findings highlight how VirB is not a conventional transcriptional regulator and broaden our perspective on transcriptional control in bacteria. Furthermore, this work contributes to our understanding of long-range gene regulatory effects, which are frequently overlooked and poorly characterized in bacteria.

Neuronal Or Intestinal Knockdown Of C. Elegans Nadk-1 Decreases Oxygen Consumption And Reactive Oxygen Species, Jake Regan

Electronic Theses and Dissertations

Reactive oxygen species (ROS) such as H2O2 can damage cellular components and are formed as a byproduct of mitochondrial oxidative metabolism. Studies using the nematode C. elegans have found that increasing ROS during development or early adulthood can extend lifespan, while increasing ROS during later adulthood normally decreases lifespan. NADPH provides the reducing power for several cellular antioxidants and is synthesized in a two-step reaction from NAD+ with the first step being catalyzed by NAD kinase (NADK). In this study, the effects of knocking down C. elegans cytoplasmic NADK, nadk-1 globally or in a neuron or intestine-specific manner starting from …