Biochemistry Commons^™

Enhanced Bypass Of Pd-L1 Translation Reduces The Therapeutic Response To Mtor Kinase Inhibitors, Yanan Cao, Qing Ye, Murong Ma, Qing-Bai She

Markey Cancer Center Faculty Publications

Increased PD-L1 expression in cancer cells is known to enhance immunosuppression, but the mechanism underlying PD-L1 upregulation is incompletely characterized. We show that PD-L1 expression is upregulated through internal ribosomal entry site (IRES)-mediated translation upon mTORC1 inhibition. We identify an IRES element in the PD-L1 50-UTR that permits cap-independent translation and promotes continuous production of PD-L1 protein despite effective inhibition of mTORC1. eIF4A is found to be a key PD-L1 IRES-binding protein that enhances PD-L1 IRES activity and protein production in tumor cells treated with mTOR kinase inhibitors (mTORkis). Notably, treatment with mTORkis in vivo elevates PD-L1 levels and reduces …

Messes: Software For Transforming Messy Research Datasets Into Clean Submissions To Metabolomics Workbench For Public Sharing, P. Travis Thompson, Hunter N. B. Moseley

Markey Cancer Center Faculty Publications

In recent years, the FAIR guiding principles and the broader concept of open science has grown in importance in academic research, especially as funding entities have aggressively promoted public sharing of research products. Key to public research sharing is deposition of datasets into online data repositories, but it can be a chore to transform messy unstructured data into the forms required by these repositories. To help generate Metabolomics Workbench depositions, we have developed the MESSES (Metadata from Experimental SpreadSheets Extraction System) software package, implemented in the Python 3 programming language and supported on Linux, Windows, and Mac operating systems. MESSES …

The Metabolomics Workbench File Status Website: A Metadata Repository Promoting Fair Principles Of Metabolomics Data, Christian D. Powell, Hunter N. B. Moseley

Markey Cancer Center Faculty Publications

Background: An updated version of the mwtab Python package for programmatic access to the Metabolomics Workbench (MetabolomicsWB) data repository was released at the beginning of 2021. Along with updating the package to match the changes to MetabolomicsWB’s ‘mwTab’ file format specification and enhancing the package’s functionality, the included validation facilities were used to detect and catalog file inconsistencies and errors across all publicly available datasets in MetabolomicsWB.

Results: The MetabolomicsWB File Status website was developed to provide continuous validation of MetabolomicsWB data files and a useful interface to all found inconsistencies and errors. This list of detectable issues/errors include format …

Examining Parent-Of-Origin Effects On Transcription And Rna Methylation In Mediating Aggressive Behavior In Honey Bees (Apis Mellifera), Sean T. Bresnahan, Ellen Lee, Lindsay Clark, Rong Ma, Michael P. Markey, Juliana Rangel, Christina M. Grozinger, Hongmei Li-Byarlay

Biochemistry and Molecular Biology Faculty Publications

Conflict between genes inherited from the mother (matrigenes) and the father (patrigenes) is predicted to arise during social interactions among offspring if these genes are not evenly distributed among offspring genotypes. This intragenomic conflict drives parent-specific transcription patterns in offspring resulting from parent-specific epigenetic modifications. Previous tests of the kinship theory of intragenomic conflict in honey bees (Apis mellifera) provided evidence in support of theoretical predictions for variation in worker reproduction, which is associated with extreme variation in morphology and behavior. However, more subtle behaviors – such as aggression – have not been extensively studied. Additionally, the canonical epigenetic mark …

Synthesis And Study Of High-Spin Stable Organic Radicals For Electrical Conductors And Mannosamine Nitroxide For Mri Contrast Agents, Shuyang Zhang

Department of Chemistry: Dissertations, Theses, and Student Research

In the first project, we describe the synthesis of an ambient stable high spin organic diradical 4 based on the Blatter moiety. The high-spin (S = 1) organic diradical 4, which consists of two Blatter radical moieties in a conjugated structure, exhibits a nearly exclusive population (88%) on triplet ground state at room temperature as a consequence of a large single-triplet energy gap (ΔEST = 0.5 kcal/mol). The target diradical molecule is synthesized over five steps with structural confirmation by single-crystal X-ray diffraction. The thermogravimetric analysis (TGA) shows the onset of decomposition at ~264 oC, indicating the diradical molecule has …

Multi-Target Ligand-Guided Selection (Ligs) Against B-Cell Specific Antigens Expressed In A Single Lymphoma Cell Population, Nicole B. Williams

Dissertations, Theses, and Capstone Projects

Nucleic acid ligands called aptamers are single-stranded DNA or RNA molecules which fold into functional three-dimensional structures to facilitate their target binding with high affinity and specificity. The method used to generate aptamers is an in vitro process called Systematic Evolution of Ligands by Exponential enrichment (SELEX). A variant of SELEX, cell-SELEX has been used to select aptamers against cell-surface proteins in their native state. We recently introduced a novel method called Ligand-Guided Selection (LIGS) to identify aptamers against cell-surface markers. Herein, we expanded LIGS method into a multiplexing platform to partition multiple aptamers against B-cell-specific antigens, CD19 and CD20, …

Differential Inhibition Of Anaplerotic Pyruvate Carboxylation And Glutaminolysis-Fueled Anabolism Underlies Distinct Toxicity Of Selenium Agents In Human Lung Cancer, Teresa W-M Fan, Jason Winnike, Ahmad Al-Attar, Alex C. Belshoff, Pawel Lorkiewicz, Jin Lian Tan, Min Wu, Richard M. Higashi, Andrew N. Lane

Markey Cancer Center Faculty Publications

Past chemopreventive human trials on dietary selenium supplements produced controversial outcomes. They largely employed selenomethionine (SeM)-based diets. SeM was less toxic than selenite or methylseleninic acid (MSeA) to lung cancer cells. We thus investigated the toxic action of these Se agents in two non-small cell lung cancer (NSCLC) cell lines and ex vivo organotypic cultures (OTC) of NSCLC patient lung tissues. Stable isotope-resolved metabolomics (SIRM) using 13C6-glucose and 13C5,15N2-glutamine tracers with gene knockdowns were employed to examine metabolic dysregulations associated with cell type- and treatment-dependent phenotypic changes. Inhibition of key anaplerotic processes, pyruvate carboxylation (PyC) and glutaminolysis were elicited by …

Noncovalent Interactions That Tune The Reactivities Of The Flavins In Bifurcating Electron Transferring Flavoprotein, María González-Viegas, Rajiv K. Kar, Anne-Frances Miller, Maria-Andrea Mroginski

Markey Cancer Center Faculty Publications

Bifurcating electron transferring flavoproteins (Bf-ETFs) tune chemically identical flavins to two contrasting roles. To understand how, we used hybrid quantum mechanical molecular mechanical calculations to characterize noncovalent interactions applied to each flavin by the protein. Our computations replicated the differences between the reactivities of the flavins: the electron transferring flavin ( ETflavin) was calculated to stabilize anionic semiquinone (ASQ) as needed to execute its single-electron transfers, whereas the Bf flavin (Bfflavin) was found to disfavor the ASQ state more than does free flavin and to be less susceptible to reduction. The stability of ETflavin ASQ was attributed in part to …

Novel Isolation Method Reveals Sex-Specific Composition And Neurotoxicity Of Small Extracellular Vesicles In A Mouse Model Of Alzheimer’S Disease, Ahmed Elsherbini, Zhihui Zhu, Zainuddin Quadri, Simone M. Crivelli, Xiaojia Ren, Hemendra J. Vekaria, Priyanka Tripathi, Liping Zhang, Wenbo Zhi, Erhard Bieberich

Markey Cancer Center Faculty Publications

We developed a new method to isolate small extracellular vesicles (sEVs) from male and female wild-type and 5xFAD mouse brains to investigate the sex-specific functions of sEVs in Alzheimer’s disease (AD). A mass spectrometric analysis revealed that sEVs contained proteins critical for EV formation and Aβ. ExoView analysis showed that female mice contained more GFAP and Aβ-labeled sEVs, suggesting that a larger proportion of sEVs from the female brain is derived from astrocytes and/or more likely to bind to Aβ. Moreover, sEVs from female brains had more acid sphingomyelinase (ASM) and ceramide, an enzyme and its sphingolipid product important for …

Molecular Mechanisms Protecting Centromeres From Self-Sabotage And Implications For Cancer Therapy, Rim Nassar, Lily Thompson, Elise Fouquerel

Student Papers, Posters & Projects

Centromeres play a crucial role in DNA segregation by mediating the cohesion and separation of sister chromatids during cell division. Centromere dysfunction, breakage or compromised centromeric integrity can generate aneuploidies and chromosomal instability, which are cellular features associated with cancer initiation and progression. Maintaining centromere integrity is thus essential for genome stability. However, the centromere itself is prone to DNA breaks, likely due to its intrinsically fragile nature. Centromeres are complex genomic loci that are composed of highly repetitive DNA sequences and secondary structures and require the recruitment and homeostasis of a centromere-associated protein network. The molecular mechanisms engaged to …

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)

Effects Of Membrane Components On The Oligomerization Of Amyloid-Β (Aβ) In Alzheimer Disease, Jhinuk Saha

Dissertations

Deposition of extracellular proteinaceous plaques of amyloid-β (Aβ) is one of the major hallmarks of Alzheimer disease (AD). Although, insoluble high molecular fibrils of Aβ are the main constituents of the senile plaques in AD, low molecular weight soluble Aβ oligomers have emerged as the key toxic species involved in memory impairment and neuronal cell death in AD. The process for generation of oligomers can be highly diverse and can involve homotypic interactions of Aβ as well as heterotypic interaction of Aβ with other macromolecules. Previously, the generation of Aβ oligomers with distinct biochemical and biophysical characteristics catalyzed non-esterified fatty …

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 …

A Critical Assessment Of The Role Of Clpxp-Mediated Proteolysis In The Development And Differentiation Of Chlamydia Trachomatis, Nicholas A. Wood

Theses & Dissertations

Chlamydia trachomatis, an obligate intracellular human pathogen, is the etiological agent of the most commonly reported bacterial sexually transmitted infection and the leading cause of preventable infectious blindness worldwide. In adapting to an intracellular niche, Chlamydia has evolved to eliminate superfluous genes from its chromosome. Despite its highly reduced genome, Chlamydia undergoes a complex developmental cycle in which the bacteria differentiate between two functionally and morphologically distinct forms: the infectious, non-replicative elementary body (EB) and the non-infectious, replicative reticulate body (RB). An EB initiates infection by binding to and inducing uptake into a host cell. Within the cell, the EB …

Review Of Biomedical Applications Of Cardiovascular Tissue Engineering, Natalie M. Howard

Honors College Theses

Tissue engineering can be defined as processes that aim to generate three-dimensional functional tissues in vitrothat have been favorably altered according to the structural, biochemical, electrophysiological, and biomechanical properties of the desired tissue before implantation into the human body. In relation to cardiac tissues, these properties would include the ability to conduct action potentials, withstand systolic pressure, permit sufficient O₂ and CO₂penetration, sufficient vascularization to supply nutrients for cellular activity, surface topology that enables cellular communication, and more. As heart diseases and instances of myocardial infarction continue to rise worldwide, there is an increasing need for …

Combination Therapy With Trastuzumab And Niraparib: Quantifying Early Proliferative Alterations In Her2+ Breast Cancer Models, Ameer Mansur, Patrick N. Song, Yun Lu, Andrew C. Burns, Luke Sligh, Eddy S. Yang, Anna G. Sorace

Markey Cancer Center Faculty Publications

HER2–targeted treatments have improved survival rates in HER2+ breast cancer patients, yet poor responsiveness remains a major clinical obstacle. Recently, HER2+ breast cancer cells, both resistant and responsive to HER2–targeted therapies, have demonstrated sensitivity to poly–(ADP– ribose) polymerase (PARP) inhibition, independent of DNA repair deficiencies. This study seeks to describe biological factors that precede cell viability changes in response to the combination of trastuzumab and PARP inhibition. Treatment response was evaluated in HER2+ and HER2– breast cancer cells. Further, we evaluated the utility of 3′–Deoxy–3′–[18F]–fluorothymidine positron emission tomography ([18F]FLT–PET) imaging for early response assessment in a HER2+ patient derived xenograft …

Methyltransferase, Glucose Adaptation, And Import Complex In Trypanosoma Brucei, Emily Knight

All Dissertations

Trypanosoma brucei is a kinetoplastid parasite responsible for human African trypanosomiasis (HAT) and nagana, a livestock wasting disease, which both endemic to sub-Saharan Africa. Unique to kinetoplastids are the specialized peroxisomes, named glycosomes, which compartmentalize the first several steps of glycolysis and gluconeogenesis, nucleotide sugar biosynthesis, and many other metabolic processes. Kinetoplastids are unique in that they have a single mitochondrion. In this work, I present the first study into SET domain proteins in any kinetoplastid parasites. We have characterized a predicted SET domain protein, TbSETD3, that localizes to the mitochondrion and a depletion of the protein results in growth …

Spatial Metabolomics Reveals Glycogen As An Actionable Target For Pulmonary Fibrosis, Lindsey R. Conroy, Harrison A. Clarke, Derek B. Allison, Samuel Santos Valenca, Qi Sun, Tara R. Hawkinson, Lyndsay E. A. Young, Juanita E. Ferreira, Autumn V. Hammonds, Jaclyn B. Dunne, Robert J. Mcdonald, Kimberly J. Absher, Brittany Dong, Ronald C. Bruntz, Kia H. Markussen, Jelena A. Juras, Warren J. Alilain, Jinze Liu, Matthew S. Gentry, Peggi M. Angel, Christopher M. Waters, Ramon C. Sun

Saha Cardiovascular Research Center Faculty Publications

Matrix assisted laser desorption/ionization imaging has greatly improved our understanding of spatial biology, however a robust bioinformatic pipeline for data analysis is lacking. Here, we demonstrate the application of high- dimensionality reduction/spatial clustering and histopathological annotation of matrix assisted laser desorption/ionization imaging datasets to assess tissue metabolic heterogeneity in human lung diseases. Using metabolic features identified from this pipeline, we hypothesize that metabolic channeling between glycogen and N-linked glycans is a critical metabolic process favoring pulmonary fibrosis progression. To test our hypothesis, we induced pulmonary fibrosis in two different mouse models with lysosomal glycogen utilization deficiency. Both mouse models displayed …

Targeting Metabolic Alterations Associated With Smooth Muscle Α-Actin Pathogenic Variant Attenuates Moyamoya-Like Cerebrovascular Disease, Anita Kaw

Dissertations and Theses (Open Access)

Heterozygous pathogenic variants in ACTA2, encoding smooth muscle α-actin (α-SMA), predispose to thoracic aortic aneurysms and dissections. De novo missense variants disrupting ACTA2 arginine 179 (p.Arg179) cause a multisystemic disease termed smooth muscle dysfunction syndrome (SMDS), which is characterized by early onset thoracic aortic disease and moyamoya disease-like (MMD) cerebrovascular disease. The MMD-like cerebrovascular disease in SMDS patients is marked by bilateral steno-occlusive lesions in the distal internal carotid arteries (ICAs) and their branches. To study the molecular mechanisms that underlie the ACTA2 p.Arg179 variants, a smooth muscle-specific Cre-lox knock-in mouse model of the heterozygous Acta2 R179C variant, termed …

New Dna Repair And Demethylation Functions In Uracil Dna Glycosylase Superfamily, Chenyan Chang

All Dissertations

Uracil-DNA glycosylase (UDG) superfamily, which consists of several groups of enzymes that recognize the damaged DNA bases and initiate the base excision repair (BER) pathway, is most important in dealing with DNA deamination and other base modifications. Thymine DNA glycosylase (TDG), which belongs to family 2 in the UDG superfamily, is able to specifically recognize and cleave the 5-methylcytosine (mC) oxidative derivatives including 5-formylcytosine (fC), 5-carboxylcytosine (caC), 5-hydromethyluracil (hmU) caused by active demethylation or DNA damage. My dissertation work is mainly focused on the fC and caC glycosylase activity within UDG superfamily. Chapter 1 is a general introduction to the …

Acetate Metabolism In The Fungal Pathogen Cryptococcus Neoformans, Oly Ahmed

All Dissertations

Cryptococcus neoformans is an environmental basidiomycetous fungus with a worldwide distribution and a wide range of habitats. Inhalation of the desiccated yeasts or spores of C. neoformans often leads to opportunistic pulmonary infections in immunocompromised individuals, and in severe cases causes lethal meningitis following hematogenous dissemination. During infection, depending on the tissue and disease state, the invading fungi experience a range of nutrient microenvironments within the host body. As a result, rapid metabolic adaptations geared towards efficient utilization of carbon sources alternative to glucose become one of the prime determinants of survival and growth for the pathogen. Incidentally, cryptococcal infection …

Effects Of Cations And Dipicolinic Acid On B. Anthracis Spore Physiology And Cytotoxicity, Chandler P. Hassan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Inhalation of Bacillus anthracis spores leads to the most severe form of anthrax. Following phagocytosis by alveolar macrophages, spores germinate inside the phagolysosome. The mechanism used by the newly germinated B. anthracis cells to survive within macrophages is not completely understood.B. anthracis spores contain large concentrations of calcium in complex with dipicolinic acid (Ca-DPA). Upon germination, the cell excretes the large depot of Ca-DPA. DPA is an amphipathic molecule that could act as a buffer and modulate phagolysosome acidification. Intracellular calcium overload can disrupt signaling pathways required for normal macrophage function and trigger cell death. We hypothesized the release of …

Potential Use Of The Gel Extract Of Butterfly Pea Flower As Topical Therapy To Prevent Photodamage By Downregulating Tnf-Α And Caspase-3 Expression Levels In Uvb-Exposed Rats, Elvana Cahyani, Agung Putra, Prasetyowati Subchan

Makara Journal of Health Research

Background: Prolonged exposure to UVB radiation causes DNA damage in skin cells by raising the levels of reactive oxygen species, resulting in the production of inflammatory factors and skin issues. Plant extracts are frequently used to counteract photodamage due to their antioxidant properties. One example is the floral extract of the butterfly pea plant, which contains flavonoid antioxidants. However, the effect of the extract on inflammatory factors is unknown. This study investigated how tumor necrosis factor-alpha (TNF-α) and caspase-3 expression changed when a butterfly pea flower extract gel was applied topically to UVB-exposed animals.

Methods: Experimental and control …

Investigating The Helicase Activity Of Methylated Vs Unmethylated Ded1, Hannah Lukow

Honors Theses

Ded1 is an RNA helicase protein of the DEAD-box subfamily in eukaryotic organisms (Sharma & Jankowsky, 2014) which can act as an activator or initiation factor, during translation (Hilliker et al., 2011). Ded1 has several functions in yeast including assembly of translational initiation factors, scanning the mRNA for the start codon, and unwinding any double stranded segments of mRNA with its helicase ability. Ded1 was discovered to be methylated at four arginine sites in vivo (Low et al., 2013), with a fifth methylation site being discovered recently (Low et al., 2020), however the purpose of such post-translational modifications is still …

The Role Of Cerium(Iii) In Bacterial Growth And The Microbial Transformation Of Aromatic Hydrocarbons, Shruti Sathish

Honors Theses

Biofilms are communities of surface-attached bacterial cells encased in an exopolymeric matrix. In this state, they are more resistant to antimicrobial treatment and can have adverse effects in medical, agricultural, and industrial settings. Whereas, as biocatalysts, biofilms from nonpathogenic bacteria enhance their performance and stability in catalysis. Unfortunately, there are several challenges when using bacteria in organic transformations due to their complex cellular chemistry. Trivalent lanthanide metals were discovered to serve regulatory roles in some bacterial catalytic processes, including those of Pseudomonas putida KT2440 (P. putida), a non-infectious Gram-negative bacterium. The main goal of our research is to use cerium(III) …

Novel Plant Peroxidase Investigation For Use In Various Biochemical And Practical Applications, Sally Hess

Liberty University Research Week

Undergraduate

Basic

Characterization Of Select Lysine Mutations Of The Cystine/Glutamate Transporter, System XC-, Anna Koppin, Claire Buck, Amanda Gibson

22nd Annual Celebration of Undergraduate Research and Creative Activity (2023)

System xc- is a membrane transport system that plays a critical role in mitigating oxidative stress. As such, its regulation is critical for proper brain functioning. Recent work in our lab has shown that System xc- activity increases immediately during an oxidative insult by undergoing a change in localization to the plasma membrane, but we have yet to identify the specific mechanism for the redistribution of the transporter. Previous studies have demonstrated that post-translational modifications of proteins can lead to differential protein distribution within cells. Therefore, in this study, we sought to determine if post-translational modification (PTM) of the transporter …

Does Phosphorylation On Serine 26 Of System Xc- Lead To Changes In Cell Surface Expression?, Katherine Lane

22nd Annual Celebration of Undergraduate Research and Creative Activity (2023)

System x_c^- is involved in transporting cystine into cells and glutamate out of cells, and ultimately in production of the antioxidant glutathione. Antioxidants are important in protecting cells from oxidative stress which can occur when waste products like H₂O₂ build up in the cell. Previous studies have shown that a critical regulator mTORC regulates system xc- by phosphorylating serine 26 (S26) on the N-terminus of the cystine/glutamate antiporter xCT, leading to a reduction in transport activity. The specific objective of this study is to determine the mechanism by which phosphorylation of S26 affects activity. To …

Creation Of An N-Terminal Xct Mutant Lacking Lysines For Use In Protein Turnover Studies, Alexandria Switzer

22nd Annual Celebration of Undergraduate Research and Creative Activity (2023)

xCT plays a role in protecting cells from oxidative stress as well as intracellular glutathione synthesis. If this process is impeded, reactive oxygen species accumulate in the cell, leading to cellular damage, and if left unchecked, it can lead to neuronal loss. Ubiquitin is a small protein that some evidence suggests can negatively affect the stress response pathway modulated by xCT, as well as induce cell death. It is hypothesized that ubiquitin binds to xCT on the N-terminal lysine residues, and there are six conserved lysines in the N-terminal domain at positions K4R, K12R, K30R, K37R, K41R, and K43R. Previous …

Early Life Δ9-Tetrahydrocannabinol Exposure Of F0 Zebrafish Causes Hyperactivity In F1 Offspring, Jenna Cripe

Honors Theses

As cannabis increases in its accessibility, potency, and acceptance across the United States, investigation into the multigenerational effects of Δ9-tetrahydrocannabinol (THC) exposure during key stages of development is critical. The aim of this study was to evaluate whether there would be behavioral impacts in the F1 offspring following a dose-response of THC exposure (0.08, 0.4, or 1 µM) during development in the F0 generation. Zebrafish (Danio rerio) were utilized in this study. Behaviors (locomotive activity and anxiety-like behavior) in the F1 generation were evaluated at 120 hours post-fertilization (hpf) with the larval photometer response (LPR) assay, and at 3, 11, …