bluuebunny/crossref_metadata_2025_split huggingface dataset:
OspC's Pivotal Role in Lyme Disease Infection and Transmission
Authors: Shabbir Sanah , Spanel Jack , Wagoner Natalie 
Published: June 2021

The Olathe North MSOE Center for BioMolecular Modeling SMART Team used 3‐D modeling and printing technology to examine structure‐function of OspC. Lyme disease is a tick‐borne illness caused by the spirochetal bacterium Borrelia burgdorferi. It is the most commonly occurring vector‐borne disease in the United States and if not treated, Lyme disease can cause carditis, arthritis and neurological symptoms. The surface of B. burgdorferi is covered by surface lipoproteins. One of them is the outer surface lipoprotein C (OspC). The ospC gene is located on a plasmid and expressed by the bacteria during their transmission from ticks to warm‐blooded hosts. OspC is critical for colonization of the host and begins to be synthesized by the bacteria when the blood and its nutrients enters the tick's midgut upon a tick bite. The presence of OspC promotes the movement of B. burgdorferi from the midgut to the salivary glands, allowing the bacteria to be injected with the tick saliva into the host. The tick salivary protein Salp15 binds to portions of OspC and interferes with the initial host immune response, which allows the bacteria to spread to different tissues. OspC also binds plasminogen which is activated by host to the protease plasmin. The resulting coat of plasmin breaks down host tissues and offers the bacteria a pathway to disseminate further. The OspC protein is a homodimer consisting of a bundle of multiple alpha helices as well as a single beta‐pleated sheet. A region facing away from the bacterial membrane is negatively charged and may bind positively charged host ligands. This feature is unique to OspC variants that are known to cause invasive human disease. The precise biological function of OspC is unclear and its relationship between OspC variant and pathogenicity is not well understood. To further study this, mutations within, e.g,, the above mentioned negatively charged region may affect the bacteria's ability bind Salp15 or plasminogen and thus disrupt the overall effectiveness of Borrelia burgdorferi to be transmitted and cause disease.Support or Funding InformationOlathe North High School SMART TeamSponsor: Chris ElniffMentor: Dr. Wolfram Zückert, PhD, Microbiology, Molecular Genetics and Immunology, University of Kansas Medical CenterThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Structural And Functional Versatility of Interferon‐Inducible GTPases
Authors: Yin Qian , Roy Sayantan , Wang Bing , Tian Yuan , Yang Wei 
Published: June 2021

GTP triphosphatases (GTPases) have been meticulously documented for their roles to regulate multiple cellular processes spanning from cell mobility, membrane fusion and fission, to cytokinesis and vesicle transport. Interferon (IFN)‐inducible GTPases, consisting of more than forty members in human and mice, are among the most highly expressed interferon stimulated genes (ISGs), sometimes accounting for twenty percent of all proteins induced by IFN‐γ. Recent genetic and cell studies start to reveal the important roles of IFN‐inducible GTPases in restriction and elimination of pathogens, yet the molecular mechanisms are largely unclear. Using a combination of biochemical, structural, biophysical, and computational tools, we are investigating the functional forms of two IFN‐inducible GTPases, GBP2 and IRGM, and the mechanisms governing their activation. We established the relationship between nucleotide binding and the oligomeric status of GBP2. A combination of X‐ray crystallography, electron microscopy, and molecular dynamics captured GBP2 conformational changes along the full trajectory of GTP binding and hydrolysis. Structure‐guided mutagenesis validated the roles of key residues in nucleotide binding pocket. In contrast to the dynamic nature of GBP2, IRGM assumed a highly stable oligomeric state that possessed intrinsic affinity towards lipids. In conclusion, GTP binding and hydrolysis regulate the oligomeric status of interferon‐inducible GTPases and subsequential effector molecule binding.Support or Funding InformationNIAID R00AI108793 “Dissecting inflammasome anatomy: mechanistic studies and potential intervention”; Florida State University startup fundsThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Elementary Steps in Plant‐Pathogen Recognition Revealed by Enhancing the Stability and Structure of Domains of Plant Innate Immune Receptors
Authors: Eisenstein Edward , Li Jia , Walsh Scott T.R. , Bera Asim , Bakalarz Janet , Weatherwax Colleen , Pierce Brian , Parsons James 
Published: June 2021

Pathogens elicit an immune response in plants through the recognition of the avirulent effectors by multi‐domain intracellular disease resistance receptors. The nature and specificity of plant‐pathogen interactions and the molecular mechanism of eliciting an immune response is being explored using the N protein from Nicotianaglutinosa. The N protein is an archetype of the nucleotide binding (NB), leucine rich repeat (LRR) family of innate immune receptors (NLRs), and the interaction with its avirulent effector, the helicase domain (HEL) of the replicase protein of tobacco mosaic virus (TMV) triggers a classic hypersensitive cell death response in plants. An initial step in activating cell death pathways upon pathogen recognition is a structure change that enables NLR assembly through their N‐terminal Toll‐Interlukin1 Receptor‐like (TIR) domains. Stabilized domains with increased tendency to self‐associate have been constructed by focused mutagenesis guided by computational modeling of a 3.0 Å crystal structure of the N‐TIR domain. The energetics of TIR dimerization is being correlated with the severity of the hypersensitive response by measuring salicylic acid using LC‐MS to examine the hypothesis that receptor assembly is correlated with NLR signaling. Yeast surface display is being used to probe the manner whereby host NLRs recognize pathogenic determinants, and reveals that the interaction of N with its pathogen effector, the HEL domain of TMV, is mediated via its LRR domain. Binding analyses show that a stabilized LRR domain binds HEL about 250‐fold more strongly than a non‐virulent homologue that does not display a hypersensitive response. Variants of the full‐length N protein are being rebuilt from the individually stabilized TIR and LRR domains optimized for functional analyses to enable biochemical and structural investigations of plant NLR receptors.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Development of a Novel In Situ Activity Assay for Lysyl Oxidase Like‐2 (LOXL2)
Authors: Wang Huilei , Abouelkheir Mahmoud , Poe Alan , Hong Yurie , Jandu Sandeep , Nandakumar Kavitha , Santhanam Lakshmi 
Published: June 2021

Lysyl oxidase like‐2 (LOXL2) is a member of the lysyl oxidase (LOX) super family, which are copper‐dependent amine oxidases that initialize collagen and elastin cross‐linking to form a stable and organized matrix. Augmented LOXL2 expression is highly associated with diverse disease processes with a known element of matrix accumulation including fibrosis, pulmonary hypertension, and cancer metastasis. To date, lack of sensitive and specific assays that can detect LOXL2 catalytic function in situ in the extracellular matrix (ECM) of cells and tissue has limited the ability to fully elucidate the role of LOXL2 in pathobiological mechanisms.Current methods to detect LOXL2 enzymatic activity are inefficient and limited in scope. The most widely used assay is hydrogen peroxide based: oxidation of the LOX active site occurs when substrate is added to samples, and releases hydrogen peroxide. The level of hydrogen peroxide is detected using an HRP‐coupled system, that utilizes the conversion of Amplex Red to the fluorescent end product, resorufin. While the results are semi‐quantitative, this assay has limited dynamic range and cannot distinguish hydrogen peroxide arising from other pathways. Moreover, the assay requires LOXL2 in solution. The harsh conditions required to obtain a solubilized ECM sample, where the pertinent LOXL2 activity occurs, cause LOXL2 unfolding and loss of activity, rendering this assay unfeasible. Thus, there is a need to develop a sensitive, specific, and practicable in situ activity assay that overcomes these limitations.This study provides a proof of concept for a novel in situ activity assay for LOXL2. Here, we developed an assay to fluorescently label the products of LOXL2 catalysis. Specifically, LOXL2 catalyzes an oxidative de‐amination of lysine and hydroxylysine residues (found on collagen and elastin) to highly reactive semi‐aldehydes called allysines. In this assay, we labeled the newly generated allysine residues with biotin hydrazide using 1‐ethyl‐3‐(3‐dimethyl‐aminopropyl) carbodiimide hydrochloride (EDC) crosslinker. This biotinylation allows for a robust method of measuring LOXL2 activity through western blotting, immunoprecipitation and immunofluorescence imaging using biotin‐streptavidin interactions.Support or Funding InformationFunded by MedImmune research funds.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Lipophilic Modification of an Anti‐Cancer Stem Cell Agent Improves Pharmacokinetic and Anti‐Cancer Properties
Authors: Morla Shravan , Afosah Daniel K. , O'Hara Connor , Boothello Rio , Patel Bhaumik B. , Sakagami Masahiro , Desai Umesh R. 
Published: June 2021

Current anti‐cancer agents target bulk tumor cells but do not eradicate the rare, quiescent, cancer stem cells (CSCs). CSCs are being increasingly recognized as the reason for cancer relapse. Targeting CSCs has become a major area of interest in the field of anti‐cancer drug discovery and several clinical trials focused on CSC targeting are in progress. Previously, we identified a CSC selective agent G2.2 (Fig. 1), which inhibited CSC spheroidal growth with a median IC50 (±1SEM) s of 193 μM±58 μM. G2.2 was found to exhibit robust anti‐CSC properties in colorectal cancer xenograft models in vivo. Mechanistically, G2.2 is a mimetic of heparan sulfate hexasaccharide (HS06) and is perhaps the only non‐saccharide heparan sulfate mimetic identified to date to exhibit considerable anti‐cancer promise. Preliminary pharmacokinetic (PK) studies showed that G2.2 exhibited a half‐life of nearly 4 hours following IV administration and 6% bioavailability following oral administration in rats.To improve upon G2.2's PK properties, we hypothesized lipid‐modification of G2.2 would enhance penetration across GI barrier while also simultaneously enhancing its potency through better targeting of plasma‐membrane growth factor receptors – the presumed targets of G2.2 and HS06. Several lipid‐modified agents were synthesized. These modifications resulted in improvement of PK properties (bioavailability by greater than 4‐fold). Further, the analogs also showed up to ~ 53‐fold (NCI‐H508 spheroids) enhanced inhibition potency against CSCs in in‐vitro spheroid cell‐based assays. In fact, these lipid‐modified G2.2 analogs inhibited several (>10) colorectal cancer spheroids with median IC50 values (±1SEM) ranging from 8 μM±3μM to 68 μM±14μM. Considering that G2.2 is a mimetic of heparan sulfate, these results present a simple avenue to enhance drug‐like properties of such highly charged agents. The results also suggest that the lipid‐modified analogs may also serve as probes of molecular processes governing the CSC phenotype.Support or Funding InformationThis work was funded by the NHLBI grant 1P01HL107152 given to Umesh R. Desai.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Methamphetamine alters the expression of Toll‐like receptor 4 on microglia‐like cells
Authors: Rivera Dormarie E. , Martinez Luis R. 
Published: June 2021

Methamphetamine (METH) is a major public health and safety problem in the United States. METH is a strong central nervous system (CNS) stimulant that mimics the pharmacological effects of cocaine. METH abuse can also alter biological processes and immune functions necessary for host defense. Microglia are key cellular mediators of the innate immune system in the CNS and can be activated by METH in a dose‐dependent manner through the Toll‐like receptor (TLR) 4/MD2 complex. This complex could also be stimulated in microglia by interactions with pathogen‐associated molecular patterns (PAMPs) such as lipopolysaccharide (LPS) resulting in neuroinflammation and neuronal damage. Moreover, minocycline, a semi‐synthetic tetracycline derivative antimicrobial drug, inhibits microglial activation. Therefore, we hypothesized that METH impairs the microglial expression of TLR4. NR‐9460 cells, a murine microglial line derived from wild‐type mouse brain tissue, were treated with METH or minocycline for 2 h followed by incubation with LPS for 24 h. Then, flow cytometry, confocal microscopy, and western blot analyses were performed to determine the effect of METH on the expression of TLR4 receptors on microglia‐like cells. We found that METH alone increases the expression and distribution of TLR4 receptors on the surface of microglia‐like cells and changes the cellular morphology. Interestingly, after stimulation of METH–treated microglia with LPS, the TLR4 expression and distribution on the surface of these cells increases, however, the protein expression of the receptor showed no difference in total protein lysates. Our findings suggest that METH use may impair the cellular production of TLR4 in microglia. In fact, it is conceivable that METH interferes with the signaling pathways and inflammatory responses important to prevent and eradicate CNS infection. We believe this interdisciplinary project is of considerable significance in the fields of neurosciences, immunology, and drug abuse. We anticipate that our findings will result in a deeper understanding of neuroinflammation and CNS microbial infection control in METH users.Support or Funding InformationThis work was supported by NIGMS‐NIH grants: 1R15GM117501‐01A1 (LRM), and UPR‐Ponce Research Initiative for Scientific Enhancement (R25GM096955). The authors also acknowledge the support from the Border Biomedical Research Center (BBRC) at the University of Texas at El Paso (NIMHD Grant 2G12MD007592).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Comparing ROS Production in Murine Microglial Cells in Response to Two Different Types of Particulate Matter
Authors: Merrill Luke Lee , Buchmann Kelsey , Street Mikayla , Stadem Nathan , Fortuna Tyler , Mazzer Paula 
Published: June 2021

Alzheimer's and other related neurodegenerative diseases affect nearly 24.3 million individuals globally‐a number that will likely increase with the rising world population [1]. In a recent survey, a panel of experts discussed existing data and concluded that there are higher rates of dementia in developed regions than developing regions. A link between air pollution and neurodegeneration has been established [2–4]. We are looking at the ability of two different types of particulate matter, diesel exhaust and urban dust, to activate microglial cells and determine if there is an increase in oxidative stress when the microglial cells are exposed to these types of particulate matter in vitro. We utilize fluorescence and ELIZA kits to measure production of TNF‐alpha and hydrogen peroxide.Support or Funding InformationResearch reported in this publication was supported by an institutional development award from the National Institute of general medical sciences of the National Institutes of Health under grant number P20GM103443.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cell Death Induced by Airborne Particulate Matter in Murine Microglial Cells
Authors: Street Mikayla Elizabeth , Merrill Luke , Mazzer Paula 
Published: June 2021

Airborne particulate matter has been linked to neurodegeneration in recent epidemiological studies. Previous work in our lab has shown that different types of particulate matter elicit different reactions. We set out to investigate two different particulate matter types in microglial cells to see whether they would have the same effect in different types of neurological cells. We combined caspase‐3 assay with lipid profiling to determine the mode of cell death induced by several different types of airborne particulate matter. Some types of particulate matter induced cell death via apoptosis and others induced cell death by neuroinflammatory methods.Support or Funding InformationResearch reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103443. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of HealthThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Time‐Resolved Shotgun Lipidomic Analysis of Murine Astrocyte Cells Exposed to Airborne Particulate Matter
Authors: Travis Meghan , Vettrus Noah , Johansen‐Sallee Anthony , Mazzer Paula 
Published: June 2021

Millions of people around the world that are affected by neurodegenerative disease. A potential correlation has been found between neurodegenerative disease and particulate pollution. Several studies have shown oxidative stress in the brain and induction of neuroinflammation due to airborne particulate matter. Our lab has shown that urban dust induces necrosis, and diesel exhaust particulate matter induces apoptosis. I studied the the lipid profile of murine astrocyte cells exposed to urban dust and diesel exhaust at several different time points. I used shotgun lipidomics to identify all the lipid chemical species present in the cell samples. The samples were run through the 12T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (COSMIC). A key difference between the treated and untreated samples was the presence of certain ceramides. We believe these ceramides might be associated with ceramide signaling pathways in cell death.Support or Funding InformationResearch reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103443. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of HealthThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Toxicity of Electronic Cigarette Vapor on Human Oral Cells
Authors: Urena Jose Francisco , Ebersol Lauren , Silakov Alexey , Lambert Joshua 
Published: June 2021

Electronic cigarettes (ECs) have emerged as a popular alternative to conventional cigarettes. These devices operate by using resistive heating to vaporize a fluid consisting of a propylene glycol‐glycerol base, flavorings, and nicotine. Although considered safer than conventional cigarettes, recent studies have shown that EC vapor contains harmful compounds such as free radicals and carbonyls. A limited number of studies have shown that EC liquid and vapor can cause oxidative stress and cell death in vitro. While the majority of in vitro studies have focused on the toxicity in respiratory tract cell lines, the tissues in the oral cavity, which are exposed to high local concentrations of EC vapor, have been under‐studied. Our objective was to investigate the ability of EC vapor to induce cytotoxicity and oxidative stress in human oral cell lines. HGF‐1 human gingival fibroblasts and SCC‐25 human oral squamous cell carcinoma cells were exposed to a panel of commercially‐available fruit and tobacco‐flavored EC vapors using an air‐liquid interface exposure model, which mimics physiological exposures in vitro. Cytotoxicity and markers of oxidative stress were assessed after ecologically‐relevant exposure protocols. Cytotoxic EC vapors caused a greater than 30% reduction in cell viability. Nicotine was shown to ablate the effects of the cytotoxic EC vapors. There was no difference in the cytotoxic response to EC vapor between the cell lines tested. Treatment of SCC‐25 cells with a cytotoxic EC vapor caused a significant increase in intracellular ROS after a single 15 puff exposure. This increase occurred for both nicotine‐containing and nicotine‐free vapors. The differential effects of nicotine on cytotoxicity and oxidative stress suggest that either (1) cytotoxicity is not driven by ROS or (2) that nicotine protects cells by a mechanism that does not impact intracellular ROS levels. Ongoing studies are investigating the role of nicotine in this aerosolized system and the relationship between EC vapor constituents and cytotoxicity in human oral cells.Support or Funding InformationPenn State Tobacco Center of Regulatory Science; Penn State Department of Food ScienceThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.