Medical Biochemistry Commons^™

Dysregulated Gpcr Signaling And Therapeutic Options In Uveal Melanoma., Vivian Chua, Dominic Lapadula, Clinita Randolph, Jeffrey L. Benovic, Philip B. Wedegaertner, Andrew E. Aplin

Department of Biochemistry and Molecular Biology Faculty Papers

Uveal melanoma is the most common primary intraocular malignant tumor in adults and arises from the transformation of melanocytes in the uveal tract. Even after treatment of the primary tumor, up to 50% of patients succumb to metastatic disease. The liver is the predominant organ of metastasis. There is an important need to provide effective treatment options for advanced stage uveal melanoma. To provide the preclinical basis for new treatments, it is important to understand the molecular underpinnings of the disease. Recent genomic studies have shown that mutations within components of G protein-coupled receptor (GPCR) signaling are early events associated …

Determining The Protective Effects Of Quercetin Against Cadmium Toxicity In Human Embryonic Kidney Cells, Caroline N. Smith

Undergraduate Theses

Cadmium is a toxic industrial and environmental pollutant found in groundwater, air, soils, food and cigarettes. Chronic intake of low levels of cadmium has been shown to result in renal dysfunction due to cell death which can occur via apoptosis as well as necrosis. Previous studies have shown that plant extracts containing quercetin, a flavonoid found in many fruits and vegetables, protect against cadmium toxicity in rat liver hepatocytes. To determine if quercetin may have a protective effect in a cadmium-treated human embryonic kidney cell line, HEK-293 cells were treated using concentrations of cadmium chloride from 10 to 50 μM …

A Genetically Encoded Fluorescent Trna Is Active In Live-Cell Protein Synthesis., Isao Masuda, Takao Igarashi, Reiko Sakaguchi, Ram G. Nitharwal, Ryuichi Takase, Kyu Young Han, Benjamin J. Leslie, Cuiping Liu, Howard Gamper, Taekjip Ha, Suparna Sanyal, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Transfer RNAs (tRNAs) perform essential tasks for all living cells. They are major components of the ribosomal machinery for protein synthesis and they also serve in non-ribosomal pathways for regulation and signaling metabolism. We describe the development of a genetically encoded fluorescent tRNA fusion with the potential for imaging in live Escherichia coli cells. This tRNA fusion carries a Spinach aptamer that becomes fluorescent upon binding of a cell-permeable and non-toxic fluorophore. We show that, despite having a structural framework significantly larger than any natural tRNA species, this fusion is a viable probe for monitoring tRNA stability in a cellular …

Structural And Functional Analysis Of A Β2-Adrenergic Receptor Complex With Grk5., Konstantin E. Komolov, Yang Du, Nguyen Minh Duc, Robin M. Betz, João P.G.L.M. Rodrigues, Ryan D. Leib, Dhabaleswar Patra, Georgios Skiniotis, Christopher M. Adams, Ron O. Dror, Ka Young Chung, Brian K. Kobilka, Jeffrey L. Benovic

Department of Biochemistry and Molecular Biology Faculty Papers

The phosphorylation of agonist-occupied G-protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) functions to turn off G-protein signaling and turn on arrestin-mediated signaling. While a structural understanding of GPCR/G-protein and GPCR/arrestin complexes has emerged in recent years, the molecular architecture of a GPCR/GRK complex remains poorly defined. We used a comprehensive integrated approach of cross-linking, hydrogen-deuterium exchange mass spectrometry (MS), electron microscopy, mutagenesis, molecular dynamics simulations, and computational docking to analyze GRK5 interaction with the β2-adrenergic receptor (β2AR). These studies revealed a dynamic mechanism of complex formation that involves large conformational changes in the GRK5 RH/catalytic domain interface upon receptor binding. …

G Protein-Coupled Receptor Kinase-2 (Grk-2) Regulates Serotonin Metabolism Through The Monoamine Oxidase Amx-2 In Caenorhabditis Elegans., Jianjun Wang, Jiansong Luo, Dipendra K. Aryal, William C. Wetsel, Richard Nass, Jeffrey L. Benovic

Department of Biochemistry and Molecular Biology Faculty Papers

G protein-coupled receptors (GPCRs) regulate many animal behaviors. GPCR signaling is mediated by agonist-promoted interactions of GPCRs with heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. To further elucidate the role of GRKs in regulating GPCR-mediated behaviors, we utilized the genetic model system Caenorhabditis elegans Our studies demonstrate that grk-2 loss-of-function strains are egg laying-defective and contain low levels of serotonin (5-HT) and high levels of the 5-HT metabolite 5-hydroxyindole acetic acid (5-HIAA). The egg laying defect could be rescued by the expression of wild type but not by catalytically inactive grk-2 or by the selective expression of grk-2 in …

A New Class Of Inhibitors Of The Arac Family Virulence Regulator Vibrio Cholerae Toxt, Anne K. Woodbrey, Evans O. Onyango, Maria Pellegrini, Gabriela Kovacikova, Ronald Taylor, Gordon Gribble, F. Jon Kull

Dartmouth Scholarship

Vibrio cholerae is responsible for the diarrheal disease cholera that infects millions of people worldwide. While vaccines protecting against cholera exist, and oral rehydration therapy is an effective treatment method, the disease will remain a global health threat until long-term solutions such as improved sanitation and access to clean water become widely available. Because of this, there is a pressing need for potent therapeutics that can either mitigate cholera symptoms, or act prophylactically to prevent the virulent effects of a cholera infection. Here we report the design, synthesis, and characterization of a set of compounds that bind and inhibit ToxT, …

Synthesis And Anti-Hiv Activities Of Unsymmetrical Long Chain Dicarboxylate Esters Of Dinucleosides Reverse Transcriptase Inhibitors, Hitesh K. Agarwal, Bhupender S. Chhikara, Gustavo F. Doncel, Keykavous Parang

Pharmacy Faculty Articles and Research

A series of 11 unsymmetrical dinucleoside dicarboxylate conjugates of nucleoside reverse transcriptase inhibitors were synthesized. Three dicarboxylic acids, succinic acid, suberic acid and 1,14-tetradecandioc acid, were diesterified with either 3'-azido- 2',3'-dideoxythymidine (AZT), 3'-fluoro-2',3'-dideoxythymidine (FLT), 2',3'-dideoxy-3'-thiacytidine (3TC) or 5-fluoro-2',3'-dideoxy-3'- thiacytidine (FTC). The anti-HIV activity of synthesized compounds was evaluated against HIV-1 X4 (IIIB) and R5 (BaL) viral strains in single-round infection assays. Results indicated that the tetradecandioate esters of nucleosides were more active against HIV than the corresponding parent nucleosides and nucleoside conjugates. The tetradecandioate conjugate of FLT and FTC (5) was found to be the most potent compound with EC50 …

Cool-Associated Tyrosine-Phosphorylated Protein 1 Is Required For The Anchorage-Independent Growth Of Cervical Carcinoma Cells By Binding Paxillin And Promoting Akt Activation., Sungsoo M. Yoo, Arash Latifkar, Richard A. Cerione, Marc A. Antonyak

Department of Biochemistry and Molecular Biology Faculty Papers

Cool-associated tyrosine-phosphorylated protein 1 (Cat-1) is a signaling scaffold as well as an ADP-ribosylation factor-GTPase-activating protein. Although best known for its role in cell migration, we recently showed that the ability of Cat-1 to bind paxillin, a major constituent of focal complexes, is also essential for the anchorage-independent growth of HeLa cervical carcinoma cells. Here we set out to learn more about the underlying mechanism by which Cat-paxillin interactions mediate this effect. We show that knocking down paxillin expression in HeLa cells promotes their ability to form colonies in soft agar, whereas ectopically expressing paxillin in these cells inhibits this …

Na/K-Atpase Signaling And Salt Sensitivity: The Role Of Oxidative Stress, Jiang Liu, Yanling Yan, Ying Nie

Biochemistry and Microbiology

Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS)-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity.

Evaluation Of [14c] And [13c]Sucrose As Blood-Brain Barrier Permeability Markers, Mohammad K. Miah, Ekram A. Chowdhury, Ulrich Bickel, Reza Mehvar

Pharmacy Faculty Articles and Research

Non-specific quantitation of [¹⁴C]sucrose in blood and brain has been routinely used as a quantitative measure of the in vivo blood-brain barrier (BBB) integrity. However, the reported apparent brain uptake clearance (K_in) of the marker varies widely (∼100 fold). We investigated the accuracy of the use of the marker in comparison with a stable isotope of sucrose ([¹³C]sucrose) measured by a specific LC-MS/MS method. Rats received single doses of each marker, and the K_in values were determined. Surprisingly, the K_in value of [¹³C]sucrose was 6-7 fold lower than that …

Antisense Oligonucleotide Modulators Of Serotonin Receptor 2c And Uses Thereof, Stefan Stamm, Manli Shen, Serene Josiah

Molecular and Cellular Biochemistry Faculty Patents

The present invention provides, among other things, oligonucleotide modulators of human 5'-HT2C receptor (HTR2C) and improved methods and composition for treating HTR2C-related diseases, disorders or conditions based on such modulators. In particular, oligonucleotides modulators according to the invention target specific regions in the Exon V/Intron V junction of the human HTR2C pre-mRNA and drive expression of HTR2C Vb splice isoform, leading to increased generation of non-edited strong HTR2C receptor and enhanced serotonin receptor activity.

Portal Protein Functions Akin To A Dna-Sensor That Couples Genome-Packaging To Icosahedral Capsid Maturation., Ravi K. Lokareddy, Rajeshwer S. Sankhala, Ankoor Roy, Pavel V. Afonine, Tina Motwani, Carolyn M M. Teschke, Kristin N. Parent, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or 'procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity …

Urokinase Plasminogen Activator Expression Is Regulated By P53 Harboring The Lung Cancer-Specific Mutation V157f, Julie Barta, Md, Kristen Pauley, Steven B. Mcmahon, Phd

Department of Biochemistry and Molecular Biology Posters

OBJECTIVES

• To define the mutant p53-regulated transcriptome of lung cancer cells with alterations at V157 and R158 in the p53 tumor suppressor.
• To determine the biological effects of lung-enriched p53 mutations in lung cancer cells.

Cleavage Of Dfna5 By Caspase-3 During Apoptosis Mediates Progression To Secondary Necrotic/Pyroptotic Cell Death., Corey Rogers, Teresa Fernandes-Alnemri, Lindsey Mayes, Diana Alnemri, Gino Cingolani, Emad S. Alnemri

Department of Biochemistry and Molecular Biology Faculty Papers

Apoptosis is a genetically regulated cell suicide programme mediated by activation of the effector caspases 3, 6 and 7. If apoptotic cells are not scavenged, they progress to a lytic and inflammatory phase called secondary necrosis. The mechanism by which this occurs is unknown. Here we show that caspase-3 cleaves the GSDMD-related protein DFNA5 after Asp270 to generate a necrotic DFNA5-N fragment that targets the plasma membrane to induce secondary necrosis/pyroptosis. Cells that express DFNA5 progress to secondary necrosis, when stimulated with apoptotic triggers such as etoposide or vesicular stomatitis virus infection, but disassemble into small apoptotic bodies when DFNA5 …

Effects Of Estrogens On Astrocytes Exposed To Stressors, Bridget N. Smith

Theses and Dissertations

Hormone replacement therapy (HRT), used by many women to alleviate menopausal symptoms such as hot flashes and mood swings, is often a combination of horomones such as estrogens, progesterone, and conjugated equine estrogens (CEE), extracted from the urine of pregnant mares. Previous studies have found positive correlations between estradiol and cellular protection, but recent research has concluded CEE provide less protective mechanisms as compared to endogenous hormones. This research sought to compare the effects of estrogen treatments (single and combined estrogen) on viability when astrocytes were induced with stressors (epinephrine, cortisol, and low oxygen concentration). Cultured human astrocytes were treated …

Mc-Ppea As A New And More Potent Inhibitor Of Clp-Induced Sepsis And Pulmonary Inflammation Than Fk866., Peixin Huang, Mark W Lee, Keivan Sadrerafi, Daniel P. Heruth, Li Q. Zhang, Dev Maulik, Shui Qing Ye

Manuscripts, Articles, Book Chapters and Other Papers

Our previous study indicated that overexpression of nicotinamide phosphoribosyltransferase (NAMPT) aggravated acute lung injury, while knockdown of NAMPT expression attenuated ventilator-induced lung injury. Recently, we found that meta-carborane-butyl-3-(3-pyridinyl)-2E-propenamide (MC-PPEA, MC4), in which the benzoylpiperidine moiety of FK866 has been replaced by a carborane, displayed a 100-fold increase in NAMPT inhibition over FK866. Here, we determined the effects of MC4 and FK866 on cecal ligation and puncture (CLP) surgery-induced sepsis in C57BL/6J mice. MC4 showed stronger inhibitory effects than FK866 on CLP-induced mortality, serum tumor necrosis factor α (TNFα) levels, pulmonary myeloperoxidase activity, alveolar injury, and interleukin 6 and interleukin1β messenger …

Biochemical And Biophysical Methods For Analysis Of Poly(Adp-Ribose) Polymerase 1 And Its Interactions With Chromatin., Maggie H. Chassé, Uma M. Muthurajan, Nicholas J. Clark, Michael A. Kramer, Srinivas Chakravarthy, Thomas Irving, Karolin Luger

Manuscripts, Articles, Book Chapters and Other Papers

Poly (ADP-Ribose) Polymerase I (PARP-1) is a first responder to DNA damage and participates in the regulation of gene expression. The interaction of PARP-1 with chromatin and DNA is complex and involves at least two different modes of interaction. In its enzymatically inactive state, PARP-1 binds native chromatin with similar affinity as it binds free DNA ends. Automodification of PARP-1 affects interaction with chromatin and DNA to different extents. Here we describe a series of biochemical and biophysical techniques to quantify and dissect the different binding modes of PARP-1 with its various substrates. The techniques listed here allow for high …

Reactive Oxygen Species-Induced Global Dna Hypomethylation In Bladder Cancer Is Mediated Via Increased Formation Of 8-Hydroxy-2'-Deoxyguanosine, Patcharawalai Whongsiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oxidative stress, as a consequence of the elevated reactive oxygen species (ROS), has been implicated in various chronic diseases including cancers by, for examples, causing oxidative DNA damage and altering epigenetic regulation. Long interspersed element-1 (LINE-1) is an only active retrotransposable elements in human DNA, comprising up to 17% of the whole genome. LINE-1 hypomethylation is reported in bladder cancer and evidently it is a consequence of oxidative stress. In this study, we investigated the expression of 5-methylcytosine (5-mC), 8-hydroxydeoxyguanosine (8-OHdG), LINE-1-endoced protein (ORF1p), histone H3K9me3 and HP1 alpha in bladder cancer tissues. Mechanistic insight into how oxidative stress affected …

Multifaceted Role Of Neuropilins In The Immune System: Potential Targets For Immunotherapy., Sohini Roy, Arup K. Bag, Rakesh Singh, James E. Talmadge, Surinder K. Batra, Kaustubh Datta

Journal Articles: Biochemistry & Molecular Biology

Neuropilins (NRPs) are non-tyrosine kinase cell surface glycoproteins expressed in all vertebrates and widely conserved across species. The two isoforms, such as neuropilin-1 (NRP1) and neuropilin-2 (NRP2), mainly act as coreceptors for class III Semaphorins and for members of the vascular endothelial growth factor family of molecules and are widely known for their role in a wide array of physiological processes, such as cardiovascular, neuronal development and patterning, angiogenesis, lymphangiogenesis, as well as various clinical disorders. Intriguingly, additional roles for NRPs occur with myeloid and lymphoid cells, in normal physiological as well as different pathological conditions, including cancer, immunological disorders, …

Hematuria Without Microalbuminuria, Angela Ferguson, Vimal Chadha, Amy Wiebold, Uttam Garg

Posters

Background

Microabubiminuria is a condition in which small amounts of albumin are excreted in the urine without overt nephropathy. Based on the

American Diabetic Association classification, microalbuminuria is defined as urinary excretion of albumin of 30–300 mg per 24 hours or 20–200 mcg/min or 30–300 mcg/mg creatinine. Various conditions such as diabetes, hypertension, and impaired renal tubular reabsorption can lead to microalbuminuria. Microalbuminuria is an indicator and predictor of the development of overt nephropathy. If identified and treated early, overt nephropathy can be prevented and averted. Proteinuria and hematuria are the two most common urinary abnormalities encountered during routine urinalysis. …