Biochemistry, Biophysics, and Structural Biology 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 …

Amyloid-Beta Protein Concentration Dependence Of Reversible Aggregation Using Gold Colloid Particles, Renee Spencer, Lila Kocieniewski, Bryan Martinez, Kazushige Yokoyama

McNair Scholars Program

Although Alzheimer’s and COVID-19 are different diseases, the commonality between them is during the process of them developing in a person by fibrillogenesis. The product of fibrillogenesis results in the development of these diseases. We study the first stage of fibrillogenesis where the amyloid-beta peptide monomers are assembled into an oligomer. We want to isolate this oligomer using gold colloids because this step can be reversed. Utilizing gold colloids allows us to freeze fibrillogenesis in the first step by folding and unfolding the protein repeatedly through a series of pH changes from 4 or below to 10 or higher. At …

Exploring The Interactions Between Sars-Cov-2 And Host Proteins, Sojan Shrestha

School of Biological Sciences: Dissertations, Theses, and Student Research

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the current pandemic, Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 is considered to be of zoonotic origin; it originated in non-human animals and was transmitted to humans. Since the early stage of the pandemic, however, the evidence of transmissions from humans to animals (reverse zoonoses) has been found in multiple animal species including mink, white-tailed deer, and pet and zoo animals. Furthermore, secondary zoonotic events of SARS-CoV-2, transmissions from animals to humans, have been also reported. It is suggested that non-human hosts can act as SARS-CoV-2 reservoirs where accumulated …

Characterization Of Atrial And Ventricular Remodeling In An Improved Minimally Invasive Mouse Model Of Transverse Aortic Constriction, Jose Alberto Navarro-Garcia, Satadru K Lahiri, Yuriana Aguilar-Sanchez, Anilkumar K Reddy, Xander H T Wehrens

Faculty, Staff and Students Publications

INTRODUCTION: Heart failure (HF) is the leading cause of death worldwide. Most large and small animal disease models of HF are based on surgical procedures. A common surgical technique to induce HF is transverse aortic constriction (TAC), which induces pressure overload. The conventional TAC (cTAC) procedure is a highly invasive surgery that is associated with severe inflammation and excessive perioperative deaths.

AIM: To establish an improved, minimally invasive TAC (mTAC) procedure that does not require thoracotomy.

METHODS AND RESULTS: Following anesthesia, mice were intubated, and a small incision was made at the neck and chest. After cutting the sternum about …

Testis-Specific Serine Kinase 3 Is Required For Sperm Morphogenesis And Male Fertility, Kaori Nozawa, Thomas X Garcia, Katarzyna Kent, Mei Leng, Antrix Jain, Anna Malovannaya, Fei Yuan, Zhifeng Yu, Masahito Ikawa, Martin M Matzuk

Faculty, Staff and Students Publications

BACKGROUND: The importance of phosphorylation in sperm during spermatogenesis has not been pursued extensively. Testis-specific serine kinase 3 (Tssk3) is a conserved gene, but TSSK3 kinase functions and phosphorylation substrates of TSSK3 are not known.

OBJECTIVE: The goals of our studies were to understand the mechanism of action of TSSK3.

MATERIALS AND METHODS: We analyzed the localization of TSSK3 in sperm, used CRISPR/Cas9 to generate Tssk3 knockout (KO) mice in which nearly all of the Tssk3 open reading frame was deleted (ensuring it is a null mutation), analyzed the fertility of Tssk3 KO mice by breeding mice for 4 months, …

Advancing Asms With Lc-Ms/Ms For The Discovery Of Novel Pdcl2 Ligands From Dna-Encoded Chemical Library Selections, Qiuji Ye, Hassane Belabed, Yong Wang, Zhifeng Yu, Murugesan Palaniappan, Jian-Yuan Li, Stacey A Kalovidouris, Kevin R Mackenzie, Mingxing Teng, Damian W Young, Yoshitaka Fujihara, Martin M Matzuk

Faculty, Staff and Students Publications

BACKGROUND: A safe, effective, and reversible nonhormonal male contraceptive drug is greatly needed for male contraception as well as for circumventing the side effects of female hormonal contraceptives. Phosducin-like 2 (PDCL2) is a testis-specific phosphoprotein in mice and humans. We recently found that male PDCL2 knockout mice are sterile due to globozoospermia caused by impaired sperm head formation, indicating that PDCL2 is a potential target for male contraception. Herein, our study for the first time developed a biophysical assay for PDCL2 allowing us to screen a series of small molecules, to study structure-activity relationships, and to discover two PDCL2 binders …

Targeting Aav Vectors To The Central Nervous System By Engineering Capsid-Receptor Interactions That Enable Crossing Of The Blood-Brain Barrier, Qin Huang, Albert T Chen, Ken Y Chan, Hikari Sorensen, Andrew J Barry, Bahar Azari, Qingxia Zheng, Thomas Beddow, Binhui Zhao, Isabelle G Tobey, Cynthia Moncada-Reid, Fatma-Elzahraa Eid, Christopher J Walkey, M Cecilia Ljungberg, William R Lagor, Jason D Heaney, Yujia A Chan, Benjamin E Deverman

Faculty, Staff and Students Publications

Viruses have evolved the ability to bind and enter cells through interactions with a wide variety of cell macromolecules. We engineered peptide-modified adeno-associated virus (AAV) capsids that transduce the brain through the introduction of de novo interactions with 2 proteins expressed on the mouse blood-brain barrier (BBB), LY6A or LY6C1. The in vivo tropisms of these capsids are predictable as they are dependent on the cell- and strain-specific expression of their target protein. This approach generated hundreds of capsids with dramatically enhanced central nervous system (CNS) tropisms within a single round of screening in vitro and secondary validation in vivo …

Safety Endpoints With Vadadustat Versus Darbepoetin Alfa In Patients With Non- Dialysis-Dependent Ckd: A Post Hoc Regional Analysis Of The Pro2tect Randomized Clinical Trial Of Esa-Treated Patients, Patrick S Parfrey, Steven K Burke, Glenn M Chertow, Kai-Uwe Eckardt, Alan G Jardine, Eldrin F Lewis, Wenli Luo, Kunihiro Matsushita, Peter A Mccullough, Todd Minga, Wolfgang C Winkelmayer

Faculty, Staff and Students Publications

RATIONALE & OBJECTIVE: In the PRO

STUDY DESIGN: Phase 3, global, open-label, randomized, active-controlled clinical trial.

SETTING & PARTICIPANTS: A total of 1,725 erythropoiesis-stimulating agent (ESA)-treated patients with anemia and NDD-CKD.

INTERVENTION: 1:1 randomization to receive vadadustat or darbepoetin alfa.

OUTCOMES: The primary safety end point was the time to first MACE.

RESULTS: At baseline, patients in Europe (n=444) were primarily treated with darbepoetin alfa, showed higher proportions on low ESA doses (/kg/wk epoetin alfa equivalents) with a hemoglobin concentration of ≥10 g/dL compared with patients in the US (n=665) and non-US/non-Europe (n=614) regions. The MACE rates per 100 person-years …

Suitability Of Double-Stranded Dna As A Molecular Standard For The Validation Of Analytical Ultracentrifugation Instruments, Maduni Ranasinghe, Jonathan M Fogg, Daniel J Catanese, Lynn Zechiedrich, Borries Demeler

Faculty, Staff and Students Publications

To address the current lack of validated molecular standards for analytical ultracentrifugation (AUC), we investigated the suitability of double-stranded DNA molecules. We compared the hydrodynamic properties of linear and circular DNA as a function of temperature. Negatively supercoiled, nicked, and linearized 333 and 339 bp minicircles were studied. We quantified the hydrodynamic properties of these DNAs at five different temperatures, ranging from 4 to 37 °C. To enhance the precision of our measurements, each sample was globally fitted over triplicates and five rotor speeds. The exceptional stability of DNA allowed each sample to be sedimented repeatedly over the course of …

Covet: A Covariation-Evolutionary Trace Method That Identifies Protein Structure-Function Modules, Daniel M Konecki, Spencer Hamrick, Chen Wang, Melina A Agosto, Theodore G Wensel, Olivier Lichtarge

Faculty, Staff and Students Publications

Measuring the relative effect that any two sequence positions have on each other may improve protein design or help better interpret coding variants. Current approaches use statistics and machine learning but rarely consider phylogenetic divergences which, as shown by Evolutionary Trace studies, provide insight into the functional impact of sequence perturbations. Here, we reframe covariation analyses in the Evolutionary Trace framework to measure the relative tolerance to perturbation of each residue pair during evolution. This approach (CovET) systematically accounts for phylogenetic divergences: at each divergence event, we penalize covariation patterns that belie evolutionary coupling. We find that while CovET approximates …

Outersphere Approach To Increasing The Persistance Of Oxygen-Sensitive Europium(Ii)-Containing Contrast Agents For Magnetic Resonance Imaging With Perfluorocarbon Nanoemulsions Toward Imaging Of Hypoxia, Jacob C Lutter, Andrea L Batchev, Caitlyn J Ortiz, Alexander G Sertage, Jonathan Romero, S A Amali S Subasinghe, Steen E Pedersen, Md Abul Hassan Samee, Robia G Pautler, Matthew J Allen

Faculty, Staff and Students Publications

Radiographic mapping of hypoxia is needed to study a wide range of diseases. Complexes of EuII are a promising class of molecules to fit this need, but they are generally limited by their rapid oxidation rates in vivo. Here, a perfluorocarbon-nanoemulsion perfused with N2, forms an interface with aqueous layers to hinder oxidation of a new perfluorocarbon-soluble complex of EuII. Conversion of the perfluorocarbon solution of EuII into nanoemulsions results in observable differences between reduced and oxidized forms by MRI both in vitro and in vivo. Oxidation in vivo occurrs over a period of ~30 min compared to <5 min for a comparable EuII-containing complex without nanoparticle interfaces. These results represent a critical step toward delivery of EuII-containing complexes in vivo for the study of hypoxia.

Twenty-Year Survival Following Lung Transplantation, John James Miggins, Ross M Reul, Spencer Barrett, Abbas Rana, Ahmed Alnajar, Jordan Dunson, Alexis Shafii, Puneet Garcha, John Goss, Gabriel Loor

Faculty, Staff and Students Publications

BACKGROUND: Lung transplantation median survival has seen improvements due to recognition of short-term survival factors but continues to trail behind other solid organs due to limited understanding of long-term survivorship. Given the creation of the United Network for Organ Sharing (UNOS) database in 1986, it was difficult to accrue data on long-term survivors until recently. This study characterizes factors impacting lung transplant survival beyond 20 years, conditional to 1-year survival.

METHODS: Lung transplant recipients listed in UNOS from 1987 to 2002 who survived to 1 post-transplant year were reviewed. Kaplan-Meier and adjusted Cox regression analyses were performed at 20 and …

Withaferin A And Immune Checkpoint Blocker Therapy For The Treatment Of Non-Small Cell Lung Cancer, Roukiah Khalil

USF Tampa Graduate Theses and Dissertations

Lung cancer is the first cause of cancer-related deaths in both men and women with an overall five-year survival rate of 28%. Although immune checkpoint blockers (ICBs) are currently FDA-approved for the treatment of non-small cell lung cancer (NSCLC), only 17-20% of patients achieve durable responses by the induction of immunologic memory. The lack of response in most patients can be attributed to the tumor-intrinsic or tumor-extrinsic immune resistance mechanisms. A biomarker of importance is the Programmed Death Ligand-1 (PD-L1), as higher PD-L1 expression is usually associated with a better response to ICBs. Although studies have attempted to combine ICBs …

Anesthetic Considerations For Cardiac Tamponade After Internal Jugular Central Line Placement During Trauma Resuscitation: A Case Report, Kevin M Chen, Jamal Hasoon, Anvinh Nguyen

Faculty, Staff and Students Publications

Numerous complications are associated with central venous catheters. Among them, cardiac tamponade is a rare but well-documented catastrophic complication. A 22-year-old healthy male presented with Code 1 trauma resulting from gunshot wounds in the abdomen. Upon examination, he was found to have a large pericardial fluid collection, a large right supraclavicular hematoma, and significant amount of bilateral pleural effusions secondary to extraluminal placement of the right internal jugular central line during resuscitation. After repairing the internal jugular injury and draining the pericardial fluid, the patient was transferred from the intensive care unit to the regular hospital floor. However, 15 days …

Quantitative Risk Assessment Of Oocyst Versus Bradyzoite Foodborne Transmission Of Toxoplasma Gondii In Brazil, Sophie Zhu, Elizabeth Vanwormer, Beatriz Martínez-López, Lílian Maria Garcia Bahia-Oliveira, Renato Augusto Damatta, Pedro Souto Rodrigues, Karen Shapiro

School of Veterinary and Biomedical Sciences: Faculty Publications

Toxoplasma gondii is a globally distributed zoonotic protozoan parasite. Infection with T. gondii can cause congenital toxoplasmosis in developing fetuses and acute outbreaks in the general population, and the disease burden is especially high in South America. Prior studies found that the environmental stage of T. gondii, oocysts, is an important source of infection in Brazil; however, no studies have quantified this risk relative to other parasite stages. We developed a Bayesian quantitative risk assessment (QRA) to estimate the relative attribution of the two primary parasite stages (bradyzoite and oocyst) that can be transmitted in foods to people in …

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 …

Neuropharmacology Of Human [Tera2.Cl.Sp12] Stem Cell-Derived Neurons In Ultra-Long-Term Culture For Antiseizure Drug Discovery, Hamed Salmanzadeh, Ankita Poojari, Atefeh Rabiee, Benjamin D. Zeitlin, Robert F. Halliwell

School of Pharmacy Faculty Articles

Modeling the complex and prolonged development of the mammalian central nervous system in vitro remains a profound challenge. Most studies of human stem cell derived neurons are conducted over days to weeks and may or may not include glia. Here we have utilized a single human pluripotent stem cell line, TERA2.cl.SP12 to derive both neurons and glial cells and determined their differentiation and functional maturation over 1 year in culture together with their ability to display epileptiform activity in response to pro-convulsant agents and to detect antiseizure drug actions. Our experiments show that these human stem cells differentiate in vitro …

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 …

Mycobacterium Avium Subsp. Paratuberculosis Candidate Vaccine Strains Are Pro-Apoptotic In Raw264.7murinemacrophages, Raul G. Barletta, John P. Bannantine, Judith R. Stabel, Ezhumalai Muthukrishnan, Dirk Anderson, Enakshy Dutta, Vamsi Manthena, Mostafa Hanafy, Denise K. Zinniel

School of Veterinary and Biomedical Sciences: Faculty Publications

Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of Johne’s disease, a severe gastroenteritis of ruminants. This study developed a model cell culture system to rapidly screen MAP mutants with vaccine potential for apoptosis. Two wild-type strains, a transposon mutant, and two deletion mutant MAP strains (MOI of 10 with 1.2 × 10⁶ CFU) were tested in murine RAW 264.7 macrophages to determine if they induce apoptosis and/or necrosis. Both deletion mutants were previously shown to be attenuated and immunogenic in primary bovine macrophages. All strains had similar growth rates, but cell morphology indicated that both deletion mutants …

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 …

Role Of Chronic Stress-Induced Neuroinflammation In Rodent Locus Coeruleus Physiology And Anxiety-Like Behaviors, Arthur Anthony Alfonso Reyes

Graduate School of Biomedical Sciences Theses and Dissertations

The locus coeruleus (LC), the primary site of brain norepinephrine (NE), is a key anatomical brain region implicated in the stress response. Stress is a neuroendocrine physiologic response to a stressor that promotes organism survival through adaptive change and restoration of homeostasis. The central stress response, which drives behavioral and physiological change, is primarily mediated by activating the hypothalamic-pituitary-adrenal (HPA) axis. While advantageous in the short term, chronic stress exposure can lead to HPA axis and LC dysregulation, which are thought to contribute to the etiology of anxiety disorders. Previous studies demonstrate the effects of acute stress in increasing LC …

Control Of The Electroporation Efficiency Of Nanosecond Pulses By Swinging The Electric Field Vector Direction, Vitalii Kim, Iurii Semenov, Allen S. Kiester, Mark A. Keppler, Bennett L. Ibey, Joel N. Bixler, Ruben M. L. Colunga Biancatelli, Andrei G. Pakhomov

Bioelectrics Publications

Reversing the pulse polarity, i.e., changing the electric field direction by 180°, inhibits electroporation and electrostimulation by nanosecond electric pulses (nsEPs). This feature, known as “bipolar cancellation,” enables selective remote targeting with nsEPs and reduces the neuromuscular side effects of ablation therapies. We analyzed the biophysical mechanisms and measured how cancellation weakens and is replaced by facilitation when nsEPs are applied from different directions at angles from 0 to 180°. Monolayers of endothelial cells were electroporated by a train of five pulses (600 ns) or five paired pulses (600 + 600 ns) applied at 1 Hz or 833 kHz. Reversing …

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 …

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 …