Other Biochemistry, Biophysics, and Structural Biology Commons^™

Disruption Of Claudin-Made Tight Junction Barriers By Clostridium Perfringens Enterotoxin: Insights From Structural Biology, Chinemerem P. Ogbu, Sourav Roy, Alex J. Vecchio

Department of Biochemistry: Faculty Publications

Claudins are a family of integral membrane proteins that enable epithelial cell/cell interactions by localizing to and driving the formation of tight junctions. Via claudin self-assembly within the membranes of adjoining cells, their extracellular domains interact, forming barriers to the paracellular transport of small molecules and ions. The bacterium Clostridium perfringens causes prevalent gastrointestinal disorders in mammals by employing an enterotoxin (CpE) that targets claudins. CpE binds to claudins at or near tight junctions in the gut and disrupts their barrier function, potentially by disabling their assembly or via cell signaling means—the mechanism(s) remain unclear. CpE ultimately destroys claudin-expressing cells …

A Glass Bead Semi‑Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares4, Daniel P. Schachtman, Sophie Alvarez, Karin Van Dijk

Department of Biochemistry: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage.

Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl …

Sesamum Indicum Diet Prevents Hyperlipidemia In Experimental Rats, Muinat M. Adeyanju, Idris A. Saheed, Oluwaseun I. Oyelekan, Taiwo A. Dele-Osibanjo, Ayodeji A. Adelegan, Adekunle J. Raimi, Samuel O. Olalekan, Olugbenga S. Alabi, Khadijat M. Alli

Department of Biochemistry: Faculty Publications

Cardiovascular diseases and metabolic complications caused by hyperlipidemia are the leading cause of death globally. In this study, the hypolipidemic potency of Sesamum indicum (SI) seeds was investigated. Of the thirty-five (35) male rats used in the study, five (5) were randomly selected for baseline measurements and thirty (30) were fed high fat diet (HFD) for four (4) weeks before random assignment into three (3) groups. The experimental group was treated with 50% SI seed, the positive control group was given a hypolipidemic drug, atorvastatin (5 mg/kg/day) while the untreated group served as the negative control. With SI administration, the …

Role Of Specialized Pro-Resolving Mediators In Reducing Neuroinflammation In Neurodegenerative Disorders, Jana Ponce, Arzu Ulu, Corrine Hanson, Erin Cameron-Smith, Jenna Wuebker, John Bertoni, Alfred Fisher, Ka-Chun Siu, Vivien Marmelat, Jiri Adamec, Danish Bhatti

Department of Biochemistry: Faculty Publications

Alzheimer’s disease (AD) and Parkinson’s disease (PD) are neurodegenerative disorders that affect millions of individuals worldwide. As incidence of these conditions increases with age, there will undoubtedly be an increased prevalence of cases in the near future. Neuroinflammation is a hallmark in the development and progression of neurodegenerative diseases and prevention or resolution of chronic neuroinflammation may represent a novel approach to treatment. The present review highlights the potential of the anti-inflammatory and pro-resolving effects of polyunsaturated fatty acid (PUFA)- derived mediators (Specialized Pro-resolving Mediators—SPM) in neurodegenerative disorders. PUFA-derived SPM are biosynthesized in response to chemicals produced from acute inflammatory …

Two Heads Are Better Than One: Current Landscape Of Integrating Qsp And Machine Learning, Tongli Zhang, Ioannis P. Androulakis, Peter Bonate, Limei Cheng, Tomáš Helikar, Jaimit Parikh, Christopher Rackauckas, Kalyanasundaram Subramanian, Carolyn R. Cho

Department of Biochemistry: Faculty Publications

Quantitative systems pharmacology (QSP) modeling is applied to address essential questions in drug development, such as the mechanism of action of a therapeutic agent and the progression of disease. Meanwhile, machine learning (ML) approaches also contribute to answering these questions via the analysis of multi-layer ‘omics’ data such as gene expression, proteomics, metabolomics, and high-throughput imaging. Furthermore, ML approaches can also be applied to aspects of QSP modeling. Both approaches are powerful tools and there is considerable interest in integrating QSP modeling and ML. So far, a few successful implementations have been carried out from which we have learned about …

Conformational Flexibility And Local Frustration In The Functional States Of The Sars-Cov-2 Spike B.1.1.7 And B.1.351 Variants: Mutation-Induced Allosteric Modulation Mechanism Of Functional Dynamics And Protein Stability, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Structural and functional studies of the SARS-CoV-2 spike proteins have recently determined distinct functional states of the B.1.1.7 and B.1.351 spike variants, providing a molecular framework for understanding the mechanisms that link the effect of mutations with the enhanced virus infectivity and transmissibility. A detailed dynamic and energetic analysis of these variants was undertaken in the present work to quantify the effects of different mutations on functional conformational changes and stability of the SARS-CoV-2 spike protein. We employed the efficient and accurate coarse-grained (CG) simulations of multiple functional states of the D614G mutant, B.1.1.7 and B.1.351 spike variants to characterize …

Functional Foods: Promising Therapeutics For Nigerian Children With Sickle Cell Diseases, Oladeji John Alabi, Fikayo Noah Adegboyega, Dolapo Samuel Olawoyin, Oluwakemi Arinola Babatunde

Department of Biochemistry: Faculty Publications

Sickle cell disease (SCD), also known as sickle cell anemia (SCA) is one of the structural hemoglobinopathies that occurs due to a single nucleotide mutation from GAG to GTG, which changes the amino acid of a β-globin chain of hemoglobin (Hb) from glutamate to valine. This singular mutation results to disorderliness in red blood cells (RBCs) with advent of changes in RBC morphology and other pathological conditions. In the 1980s, intermittent red blood cell transfusions, opioids, and penicillin prophylaxis were the only available therapy for SCA and were commonly reserved for acute, life threatening complications. So far, the US Food …

Development, Structure, And Mechanism Of Synthetic Antibodies That Target Claudin And Clostridium Perfringens Enterotoxin Complexes, Benjamin J. Orlando, Pawel K. Dominik, Sourav Roy, Chinemerem P. Ogbu, Satchal K. Erramilli, Anthony A. Kossiakoff, Alex J. Vecchio

Department of Biochemistry: Faculty Publications

Strains of Clostridium perfringens produce a two-domain enterotoxin (CpE) that afflicts humans and domesticated animals, causing prevalent gastrointestinal illnesses. CpE’s C-terminal domain (cCpE) binds cell surface receptors, followed by a restructuring of its N-terminal domain to form a membranepenetrating β-barrel pore, which is toxic to epithelial cells of the gut. The claudin family of membrane proteins are known receptors for CpE and also control the architecture and function of cell-cell contacts (tight junctions) that create barriers to intercellular molecular transport. CpE binding and assembly disables claudin barrier function and induces cytotoxicity via β-pore formation, disrupting gut homeostasis; however, a structural …

Metabolic Synergy Between Human Symbionts Bacteroides And Methanobrevibacter, Jennie L. Catlett, Sean Carr, Mikaela Cashman, Megan D. Smith, Mary Walter, Zahmeeth Sakkaff, Christine A. Kelley, Massimiliano Pierobon, Myra B. Cohen, Nicole R. Buan

Department of Biochemistry: Faculty Publications

ABSTRACT Trophic interactions between microbes are postulated to determine whether a host microbiome is healthy or causes predisposition to disease. Two abundant taxa, the Gram-negative heterotrophic bacterium Bacteroides thetaiotaomicron and the methanogenic archaeon Methanobrevibacter smithii, are proposed to have a synergistic metabolic relationship. Both organisms play vital roles in human gut health; B. thetaiotaomicron assists the host by fermenting dietary polysaccharides, whereas M. smithii consumes end-stage fermentation products and is hypothesized to relieve feedback inhibition of upstream microbes such as B. thetaiotaomicron. To study their metabolic interactions, we defined and optimized a coculture system and used software testing …

The Follicular Lymphoma Epigenome Regulates Its Microenvironment, Rada Amin, Mounia S. Braza

Department of Biochemistry: Faculty Publications

Follicular lymphoma (FL) is a B-cell non-Hodgkin lymphoma of germinal center (GC) origin with a distinctive tumor microenvironment (TME) and a unique spectrum of mutations. Despite the important therapeutic advances, FL is still incurable. During B-cell development, the GC reaction is a complex multistep process in which epigenetic regulators dynamically induce or suppress transcriptional programs. In FL, epigenetic gene mutations perturb the regulation of these programs, changing GC B-cell function and skewing differentiation towards tumor cells and altering the microenvironment interactions. FL pathogenesis and malignant transformation are promoted by epigenetic reprogramming of GC B cells that alters the immunological synapse …

Feedlot Diets Containing Different Starch Levels And Additives Change The Cecal Proteome Involved In Cattle’S Energy Metabolism And Inflammatory Response, Leone Campos Rocha, Andrey Sávio De Almeida Assunção, Renata Aparecida Martins, Victor Valério De Carvalho, Alexandre Perdigão2, Marília Afonso Rabelo Buzalaf, Jiri Adamec, Camila Pereira Braga, Danilo Domingues Millen, José Cavalcante Souza Vieira, Pedro De Magalhães Padilha

Department of Biochemistry: Faculty Publications

Diets for feedlot cattle must be a higher energy density, entailing high fermentable carbohydrate content. Feed additives are needed to reduce possible metabolic disorders. This study aimed to analyze the post-rumen effects of different levels of starch (25%, 35%, and 45%) and additives (monensin or a blend of essential oils and exogenous α-amylase) in diets for Nellore feedlot cattle. The cecum tissue proteome was analyzed via two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and then differentially expressed protein spots were identified with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The use of blends of essential oils associated with α-amylase as a feed additive promoted …

Recognition Of Extracellular Dna By Type Iv Pili Promotes Biofilm Formation By Clostridioides Difficile, Leslie A. Ronish, Ben Sidner, Yafan Yu, Kurt H. Piepenbrink

Department of Biochemistry: Faculty Publications

Clostridioides difficile is a Gram-positive bacillus, which is a frequent cause of gastrointestinal infections triggered by the depletion of the gut microbiome. Because of the frequent recurrence of these infections after antibiotic treatment, mechanisms of C. difficile persistence and recurrence, including biofilm formation, are of increasing interest. Previously, our group and others found that type IV pili, filamentous helical appendages polymerized from protein subunits, promoted microcolony and biofilm formation in C. difficile. In Gram-negative bacteria, the ability of type IV pili to mediate bacterial self-association has been explained through interactions between the pili of adjacent cells, but type …

Spatially Controlled Monolayers For Electrically Switchable Biomolecule Detection, Eduard Lukhmanov

Theses, Dissertations and Capstones

The development of biosensors that are low-waste, highly stable, and possess an ability to be interchanged between capturing and non-capturing configurations is promising for the biodetector field. Stable packing and attachment of the sensor, the ability to create an interchangeable detecting probe of interest relatively easily, and dynamic control of the probe via a reversible bias can provide for that. With the set goals to control all those properties, DNA-dendron conjugate molecules were designed, synthesized in solution, purified, and utilized to make self-assembled monolayers of single-stranded DNA on gold. To be able to manipulate the conjugates’ sensing qualities in the …

The Role Of Irf-1 In Spontaneous Mouse Glioma, Aakash B. Vaidya

Theses and Dissertations

Glioblastoma Multiforme has been shown to be one of the deadliest primary brain cancers. One of the reasons why GBM is so deadly, is a unique immunosuppressive tumor microenvironment that promotes GBM growth and progression. Both astrocyte and microglia have been implicated in immunosuppression. In this study, we explored the role of Interferon Regulatory Factor 1 (IRF-1) in astrocytes and glioma cells on the growth of spontaneous glioma tumors. IRF-1 is regulated by the JAK/STAT pathway and induces expression of Programmed death ligand 1 (PD-L1). PD-L1 downregulates immune responses to glioma. We found that IRF-1 had no effect on spontaneous …

Analysis Of The Antimicrobial Activity Of The Novel Chemotherapeutic Drug, Tpp1, Against Pseudomonas Aeruginosa And The Hydrogel Delivery Of Water-Soluble Antimicrobial Compounds, Alex Gasper

Senior Independent Study Theses

Cancer is one of the leading causes of death in the world, and it is commonly linked with bacterial infections that often complicate treatments. Recently, chemotherapeutics have been developed that are able to act as anti-cancer agents using delocalized lipophilic cations (DLCs) that are able to specifically target mitochondrial membranes of cancer cells. TPP1 is a newly developed chemotherapeutic drug that has activity against bladder cancer and melanoma cell lines in vitro. In order to determine if TPP1 has antimicrobial activity, TPP1 was tested against a common bacteria, Pseudomonas aeruginosa, to determine if antimicrobial activity was present. This testing was …

Arginine Catabolism And Polyamine Biosynthesis Pathway Disparities Within Francisella Tularensis Subpopulations, Yinshi Yue, Bhanwar Lal Puniya, Tomáš Helikar, Benjamin Girardo, Steven H. Hinrichs, Marilyn A. Larson

Department of Biochemistry: Faculty Publications

Francisella tularensis is a highly infectious zoonotic pathogen with as few as 10 organisms causing tularemia, a disease that is fatal if untreated. Although F. tularensis subspecies tularensis (type A) and subspecies holarctica (type B) share over 99.5% average nucleotide identity, notable differences exist in genomic organization and pathogenicity. The type A clade has been further divided into subtypes A.I and A.II, with A.I strains being recognized as some of the most virulent bacterial pathogens known. In this study, we report on major disparities that exist between the F. tularensis subpopulations in arginine catabolism and subsequent polyamine biosynthesis. The genes …

Addressing Barriers In Comprehensiveness, Accessibility, Reusability, Interoperability And Reproducibility Of Computational Models In Systems Biology, Anna Niarakis, Dagmar Waltemath, James Glazier, Falk Schreiber, Sarah M. Keating, David Nickerson, Claudine Chaouiya, Anne Siegel, Vincent Noël, Henning Hermjakob, Tomáš Helikar, Sylvain Soliman, Laurence Calzone

Department of Biochemistry: Faculty Publications

Computational models are often employed in systems biology to study the dynamic behaviours of complex systems. With the rise in the number of computational models, finding ways to improve the reusability of these models and their ability to reproduce virtual experiments becomes critical. Correct and effective model annotation in community-supported and standardised formats is necessary for this improvement. Here,we present recent efforts toward a common framework for annotated, accessible, reproducible and interoperable computational models in biology, and discuss key challenges of the field.

Scientists from different systems biology fields have long been developing community-driven guidelines and best practices for annotation, …

Building Digital Twins Of The Human Immune System: Toward A Roadmap, Reinhard Laubenbacher, Anna Niarakis, Tomas Helikar, G. An, B. Shapiro, R. S. Malik-Sheriff, T. J. Sego, P. Macklin, J. A. Glazier

Department of Biochemistry: Faculty Publications

Digital twins, customized simulation models pioneered in industry, are beginning to be deployed in medicine and healthcare, with some major successes, for instance in cardiovascular diagnostics and in insulin pump control. Personalized computational models are also assisting in applications ranging from drug development to treatment optimization. More advanced medical digital twins will be essential to making precision medicine a reality. Because the immune system plays an important role in such a wide range of diseases and health conditions, from fighting pathogens to autoimmune disorders, digital twins of the immune system will have an especially high impact. However, their development presents …

Endothelial Cell-Specific Deletion Of A Microrna Accelerates Atherosclerosis, Dafeng Yang, Stefan Haemmig, Jingshu Chen, Michael Mccoy, Henry S. Cheng, Haoyang Zhou, Daniel Pérez-Cremades, Xiao Cheng, Xinghui Sun, Jorge Haneo-Mejia, Shamsudheen K. Vellarikkal, Rajat M. Gupta, Victor Barrera, Mark W. Feinberg

Department of Biochemistry: Faculty Publications

Background and aims: Chronic vascular endothelial inflammation predisposes to atherosclerosis; however, the cell-autonomous roles for endothelial-expressing microRNAs (miRNAs) are poorly understood in this process. MiR-181b is expressed in several cellular constituents relevant to lesion formation. The aim of this study is to examine the role of genetic deficiency of the miR-181b locus in endothelial cells during atherogenesis.

Methods and Results: Using a proprotein convertase subtilisin/kexin type 9 (PCSK9)-induced atherosclerosis mouse model, we demonstrated that endothelial cell (EC)-specific deletion of miR-181a2b2 significantly promoted atherosclerotic lesion formation, cell adhesion molecule expression, and the influx of lesional macrophages in the vessel wall. Yet, …

Fish Oil Intake During Gestation And Lactation Attenuated Stz-Induced Diabetes Inmale Offspring Via Activation Of Brown Fat And Modulating Oxylipin Profile, Rong Fan, Shalom Thomas, Mikyoung You, Zhuoheng Li, Brandt Bessell, Bhanwar Lal Puniya, Tomáš Helikar, Zhenhua Liu, Soonkyu Chung

Department of Biochemistry: Faculty Publications

Fish oil (FO) has been demonstrated to activate brown thermogenesis and attenuate inflammation in the brown adipose tissue (BAT). Previously, we have reported thatmaternal FO supplementation promotes BAT activity of the weaned mice pups. However, whether maternal FO intake could confer sustainable metabolic benefits to offspring remains uncovered. Therefore, this study aimed to determine the differential impact of maternal FO during pregnancy versus lactation on BAT transcriptome and evaluate the role of bioactive lipid metabolites derived from maternal FO supplementation on the extended metabolic benefits of older pups in the context of type 1 diabetes (T1D).

Conclusions: Our results suggested …