Molecular Biology Commons^™

Tdp-43 Mediated Blood-Brain Barrier Permeability And Leukocyte Infiltration Promote Neurodegeneration In A Low-Grade Systemic Inflammation Mouse Model, Frank Zamudio, Anjanet R. Loon, Shayna Smeltzer, Khawla Benyamine, Nanda K. Navalpur Shanmugam, Nicholas J. F. Stewart, Daniel C. Lee, Kevin Nash, Maj-Linda B. Selenica

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Neuronal cytoplasmic inclusions containing TAR DNA-binding protein 43 (TDP-43) are a neuropathological feature of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Alzheimer's Disease (AD). Emerging evidence also indicates that systemic inflammation may be a contributor to the pathology progression of these neurodegenerative diseases.

METHODS: To investigate the role of systemic inflammation in the progression of neuronal TDP-43 pathology, AAV9 particles driven by the UCHL1 promoter were delivered to the frontal cortex of wild-type aged mice via intracranial injections to overexpress TDP-43 or green fluorescent protein (GFP) in corticospinal motor neurons. Animals were then subjected …

Pneumovirus Infections: Understanding Rsv And Hmpv Entry, Replication, And Spread, Jonathan T. Kinder

Theses and Dissertations--Molecular and Cellular Biochemistry

Pneumoviruses including human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) are significant causes of respiratory tract infections globally. Children, elderly, and immunocompromised patients are at the greatest risk for developing severe infections, which can have devastating outcomes. Although these viruses are ubiquitous with significant impacts on human health, there are no antivirals or vaccines available. The only FDA approved therapy is a monoclonal antibody for RSV, given prophylactically during the infectious season, and this treatment is only available for high risk infants. The work presented in this thesis aims to increase our understanding of how these viruses enter, replicate, and …

Itch Nuclear Translocation And H1.2 Polyubiquitination Negatively Regulate The Dna Damage Response, Lufen Chang, Lei Shen, Hu Zhou, Jing Gao, Hangyi Pan, Li Zheng, Brian Armstrong, Yang Peng, Guang Peng, Binhua P. Zhou, Steven T. Rosen, Binghui Shen

Molecular and Cellular Biochemistry Faculty Publications

The downregulation of the DNA damage response (DDR) enables aggressive tumors to achieve uncontrolled proliferation against replication stress, but the mechanisms underlying this process in tumors are relatively complex. Here, we demonstrate a mechanism through which a distinct E3 ubiquitin ligase, ITCH, modulates DDR machinery in triple-negative breast cancer (TNBC). We found that expression of a nuclear form of ITCH was significantly increased in human TNBC cell lines and tumor specimens. Phosphorylation of ITCH at Ser257 by AKT led to the nuclear localization of ITCH and ubiquitination of H1.2. The ITCH-mediated polyubiquitination of H1.2 suppressed RNF8/RNF168-dependent formation of 53BP1 foci, …

Mechanisms Of Trinucleotide Repeat Instability During Dna Synthesis, Kara Y. Chan

Theses and Dissertations--Toxicology and Cancer Biology

Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a …

Toward An Enzyme-Coupled, Bioorthogonal Platform For Methyltransferases: Probing The Specificity Of Methionine Adenosyltransferases, Tyler D. Huber

Theses and Dissertations--Pharmacy

Methyl group transfer from S-adenosyl-l-methionine (AdoMet) to various substrates including DNA, proteins, and natural products (NPs), is accomplished by methyltransferases (MTs). Analogs of AdoMet, bearing an alternative S-alkyl group can be exploited, in the context of an array of wild-type MT-catalyzed reactions, to differentially alkylate DNA, proteins, and NPs. This technology provides a means to elucidate MT targets by the MT-mediated installation of chemoselective handles from AdoMet analogs to biologically relevant molecules and affords researchers a fresh route to diversify NP scaffolds by permitting the differential alkylation of chemical sites vulnerable to NP MTs that are unreactive to …

Melatonin And Its Metabolites Protect Human Melanocytes Against Uvb-Induced Damage: Involvement Of Nrf2-Mediated Pathways, Zorica Janjetovic, Stuart G. Jarrett, Elizabeth F. Lee, Cory Duprey, Russel J. Reiter, Andrzej T. Slominski

Toxicology and Cancer Biology Faculty Publications

Ultraviolet light (UV) is an inducer of reactive oxygen species (ROS) as well as 6-4-photoproducts and cyclobutane pyrimidine dimers (CPD) in the skin, which further cause damage to the skin cells. Irradiation of cultured human melanocytes with UVB stimulated ROS production, which was reduced in cells treated with melatonin or its metabolites: 6-hydroxymelatonin (6-OHM), N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), N-acetylserotonin (NAS), and 5-methoxytryptamine (5-MT). Melatonin and its derivatives also stimulated the expression of NRF2 (nuclear factor erythroid 2 [NF-E2]-related factor 2) and its target enzymes and proteins that play an important role in cell protection from different damaging factors including UVB. Silencing …

Investigating Therapeutic Options For Lafora Disease Using Structural Biology And Translational Methods, Amanda R. Sherwood

Theses and Dissertations--Molecular and Cellular Biochemistry

Lafora disease (LD) is a rare yet invariably fatal form of epilepsy characterized by progressive degeneration of the central nervous and motor systems and accumulation of insoluble glucans within cells. LD results from mutation of either the phosphatase laforin, an enzyme that dephosphorylates cellular glycogen, or the E3 ubiquitin ligase malin, the binding partner of laforin. Currently, there are no therapeutic options for LD, or reported methods by which the specific activity of glucan phosphatases such as laforin can be easily measured. To facilitate our translational studies, we developed an assay with which the glucan phosphatase activity of laforin as …

Amalgamation Of Nucleosides And Amino Acids In Antibiotic Biosynthesis, Sandra H. Barnard

Theses and Dissertations--Pharmacy

The rapid increase in antibiotic resistance demands the identification of novel antibiotics with novel targets. One potential antibacterial target is the biosynthesis of peptidoglycan cell wall, which is both ubiquitous and necessary for bacterial survival. Both the caprazamycin-related compounds A-90289 and muraminomicin, as well as the capuramycin-related compounds A-503083 and A-102395 are potent inhibitors of the translocase I enzyme, one of the key enzymes required for cell wall biosynthesis. The caprazamycin-related compounds contain a core nonproteinogen b-hydroxy-a-amino acid referred to as 5’-C-glycyluridine (GlyU). Residing within the biosynthetic gene clusters of the aforementioned compounds is a shared open reading …

The Mir-15/107 Group Of Microrna Genes: Evolutionary Biology, Cellular Functions, And Roles In Human Diseases, John R. Finnerty, Wang-Xia Wang, Sébastien S. Hébert, Bernard R. Wilfred, Guogen Mao, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

The miR-15/107 group of microRNA (miRNA) gene is increasingly appreciated to serve key functions in humans. These miRNAs regulate gene expression involved in cell division, metabolism, stress response, and angiogenesis in vertebrate species. The miR-15/107 group has also been implicated in human cancers, cardiovascular disease and neurodegenerative disease, including Alzheimer's disease. Here we provide an overview of the following: (1) the evolution of miR-15/107 group member genes; (2) the expression levels of miRNAs in mammalian tissues; (3) evidence for overlapping gene-regulatory functions by different miRNAs; (4) the normal biochemical pathways regulated by miR-15/107 group miRNAs; and (5) the roles played …