Medicine and Health Sciences Commons^™

Similarly Efficacious Anti-Malarial Drugs Sj733 And Pyronaridine Differ In Their Ability To Remove Circulating Parasites In Mice, Arya Sheelanair, Aleksandra S. Romanczuk, Rosemary A. Aogo, Rohit Nemai Haldar, Lianne I. M. Lansink, Deborah Cromer, Yandira G. Salinas, R. Kiplin Guy, James S. Mccarthy, Miles P. Davenport, Ashraful Haque, David S. Khoury

Pharmaceutical Sciences Faculty Publications

BACKGROUND: Artemisinin-based combination therapy (ACT) has been a mainstay for malaria prevention and treatment. However, emergence of drug resistance has incentivised development of new drugs. Defining the kinetics with which circulating parasitized red blood cells (pRBC) are lost after drug treatment, referred to as the "parasite clearance curve", has been critical for assessing drug efficacy; yet underlying mechanisms remain partly unresolved. The clearance curve may be shaped both by the rate at which drugs kill parasites, and the rate at which drug-affected parasites are removed from circulation.

METHODS: In this context, two anti-malarials, SJ733, and an ACT partner drug, pyronaridine …

Interleukin 1 Alpha Administration Is Neuroprotective And Neuro-Restorative Following Experimental Ischemic Stroke, Kathleen E. Salmeron, Michael E. Maniskas, Danielle N. Edwards, Raymond Wong, Ivana Rajkovic, Amanda L. Trout, Abir A. Rahman, Samantha Hamilton, Justin F. Fraser, Emmanuel Pinteaux, Gregory J. Bix

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Stroke remains a leading cause of death and disability worldwide despite recent treatment breakthroughs. A primary event in stroke pathogenesis is the development of a potent and deleterious local and peripheral inflammatory response regulated by the pro-inflammatory cytokine interleukin-1 (IL-1). While the role of IL-1β (main released isoform) has been well studied in stroke, the role of the IL-1α isoform remains largely unknown. With increasing utilization of intravenous tissue plasminogen activator (t-PA) or thrombectomy to pharmacologically or mechanically remove ischemic stroke causing blood clots, respectively, there is interest in pairing successful cerebrovascular recanalization with neurotherapeutic pharmacological interventions (Fraser et …

Proteomic Alterations Of Hdl In Youth With Type 1 Diabetes And Their Associations With Glycemic Control: A Case-Control Study, Evgenia Gourgari, Junfeng Ma, Martin P. Playford, Nehal N. Mehta, Radoslav Goldman, Alan T. Remaley, Scott M. Gordon

Saha Cardiovascular Research Center Faculty Publications

Background: Patients with type 1 diabetes (T1DM) typically have normal or even elevated plasma high density lipoprotein (HDL) cholesterol concentrations; however, HDL protein composition can be altered without a change in cholesterol content. Alteration of the HDL proteome can result in dysfunctional HDL particles with reduced ability to protect against cardiovascular disease (CVD). The objective of this study was to compare the HDL proteomes of youth with T1DM and healthy controls (HC) and to evaluate the influence of glycemic control on HDL protein composition.

Methods: This was a cross-sectional case–control study. Blood samples were obtained from patients with T1DM and …

Efficacy Of Leukemia Inhibitory Factor As A Therapeutic For Permanent Large Vessel Stroke Differs Among Aged Male And Female Rats, Stephanie M. Davis, Lisa A. Collier, Sarah J. Goodwin, Douglas E. Lukins, David K. Powell, Keith R. Pennypacker

Neurology Faculty Publications

Preclinical studies using rodent models of stroke have had difficulty in translating their results to human patients. One possible factor behind this inability is the lack of studies utilizing aged rodents of both sexes. Previously, this lab showed that leukemia inhibitory factor (LIF) promoted recovery after stroke through antioxidant enzyme upregulation. This study examined whether LIF promotes neuroprotection in aged rats of both sexes. LIF did not reduce tissue damage in aged animals, but LIF-treated female rats showed partial motor skill recovery. The LIF receptor (LIFR) showed membrane localization in young male and aged rats of both sexes after stroke. …

Als Mutations Of Fus Suppress Protein Translation And Disrupt The Regulation Of Nonsense-Mediated Decay, Marisa Kamelgarn, Jing Chen, Lisha Kuang, Huan Jin, Edward J. Kasarskis, Haining Zhu

Toxicology and Cancer Biology Faculty Publications

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease characterized by preferential motor neuron death. Approximately 15% of ALS cases are familial, and mutations in the fused in sarcoma (FUS) gene contribute to a subset of familial ALS cases. FUS is a multifunctional protein participating in many RNA metabolism pathways. ALS-linked mutations cause a liquid–liquid phase separation of FUS protein in vitro, inducing the formation of cytoplasmic granules and inclusions. However, it remains elusive what other proteins are sequestered into the inclusions and how such a process leads to neuronal dysfunction and degeneration. In this study, we developed …

H3k9 Methyltransferases And Demethylases Control Lung Tumor-Propagating Cells And Lung Cancer Progression, S. P. Rowbotham, F Li, A. F. M. Dost, S. M. Louie, B. P. Marsh, P. Pessina, C. R. Anbarasu, Christine Fillmore Brainson, S. J. Tuminello, A. Lieberman, S. Ryeom, T. M. Schlaeger, B. J. Aronow, H. Watanabe, K. K. Wong, C. F. Kim

Toxicology and Cancer Biology Faculty Publications

Epigenetic regulators are attractive anticancer targets, but the promise of therapeutic strategies inhibiting some of these factors has not been proven in vivo or taken into account tumor cell heterogeneity. Here we show that the histone methyltransferase G9a, reported to be a therapeutic target in many cancers, is a suppressor of aggressive lung tumor-propagating cells (TPCs). Inhibition of G9a drives lung adenocarcinoma cells towards the TPC phenotype by de-repressing genes which regulate the extracellular matrix. Depletion of G9a during tumorigenesis enriches tumors in TPCs and accelerates disease progression metastasis. Depleting histone demethylases represses G9a-regulated genes and TPC phenotypes. Demethylase inhibition …

Translational Evaluation Of Acid/Base And Electrolyte Alterations In Rodent Model Of Focal Ischemia, Sarah R. Martha, Lisa A. Collier, Stephanie M. Davis, Hilary A. Seifert, Christopher C. Leonardo, Craig T. Ajmo, Elspeth A. Foran, Justin F. Fraser, Keith R. Pennypacker

Neurology Faculty Publications

BACKGROUND AND PURPOSE: Acid/base and electrolytes could provide clinically valuable information about cerebral infarct core and penumbra. We evaluated associations between acid/base and electrolyte changes and outcomes in 2 rat models of stroke, permanent, and transient middle cerebral artery occlusion.

METHODS: Three-month old Sprague-Dawley rats underwent permanent or transient middle cerebral artery occlusion. Pre- and post-middle cerebral artery occlusion venous samples for permanent and transient models provided pH, carbon dioxide, oxygen, glucose, and electrolyte values of ionized calcium, potassium, and sodium. Multiple regression determined predictors of infarct volume from these values, and Kaplan-Meier curve analyzed morality between permanent and transient …

Glutathione De Novo Synthesis But Not Recycling Process Coordinates With Glutamine Catabolism To Control Redox Homeostasis And Directs Murine T Cell Differentiation, Gaojian Lian, J. N. Rashida Gnanaprakasam, Tingting Wang, Ruohan Wu, Xuyong Chen, Lingling Liu, Yuqing Shen, Mao Yang, Jun Yang, Ying Chen, Vasilis Vasiliou, Teresa A. Cassel, Douglas R. Green, Yusen Liu, Teresa W. -M. Fan, Ruoning Wang

Toxicology and Cancer Biology Faculty Publications

Upon antigen stimulation, T lymphocytes undergo dramatic changes in metabolism to fulfill the bioenergetic, biosynthetic and redox demands of proliferation and differentiation. Glutathione (GSH) plays an essential role in controlling redox balance and cell fate. While GSH can be recycled from Glutathione disulfide (GSSG), the inhibition of this recycling pathway does not impact GSH content and murine T cell fate. By contrast, the inhibition of the de novo synthesis of GSH, by deleting either the catalytic (Gclc) or the modifier (Gclm) subunit of glutamate–cysteine ligase (Gcl), dampens intracellular GSH, increases ROS, and impact T cell differentiation. Moreover, the inhibition of …

Amperometric Self-Referencing Ceramic Based Microelectrode Arrays For D-Serine Detection, Diana Campos-Beltrán, Åsa Konradsson-Geuken, Jorge E. Quintero, Lisa Marshall

Neuroscience Faculty Publications

D-serine is the major D-amino acid in the mammalian central nervous system. As the dominant co-agonist of the endogenous synaptic NMDA receptor, D-serine plays a role in synaptic plasticity, learning, and memory. Alterations in D-serine are linked to neuropsychiatric disorders including schizophrenia. Thus, it is of increasing interest to monitor the concentration of D-serine in vivo as a relevant player in dynamic neuron-glia network activity. Here we present a procedure for amperometric detection of D-serine with self-referencing ceramic-based microelectrode arrays (MEAs) coated with D-amino acid oxidase from the yeast Rhodotorula gracilis (RgDAAO). We demonstrate in vitro D-serine recordings with a …

Protection Effect Of Exogenous Fibroblast Growth Factor 21 On The Kidney Injury In Vascular Calcification Rats, Yu-Chen Shi, Wei-Wei Lu, Yue-Long Hou, Kun Fu, Feng Gan, Shu-Juan Cheng, Shao-Ping Wang, Yong-Fen Qi, Jing-Hua Liu

Pharmacology and Nutritional Sciences Faculty Publications

Background: Chronic kidney disease (CKD) is closely related to the cardiovascular events in vascular calcification (VC). However, little has known about the characteristics of kidney injury caused by VC. Fibroblast growth factor 21 (FGF21) is an endocrine factor, which takes part in various metabolic actions with the potential to alleviate metabolic disorder diseases. Even FGF21 has been regarded as a biomarker in CKD, the role of FGF21 in CKD remains unclear. Therefore, in this study, we evaluate the FGF21 on the kidney injury in VC rats.

Methods: The male Sprague-Dawley rats were divided into three groups: (1) control group, (2) …

The Role Of The Leukemia Inhibitory Factor Receptor In Neuroprotective Signaling, Stephanie M. Davis, Keith R. Pennypacker

Center for Advanced Translational Stroke Science Faculty Publications

Several neurotropic cytokines relay their signaling through the leukemia inhibitory factor receptor. This 190kDa subunit couples with the 130kDa gp130 subunit to transduce intracellular signaling in neurons and oligodendrocytes that leads to expression of genes associated with neurosurvival. Moreover, activation of this receptor alters the phenotype of immune cells to an anti-inflammatory one. Although cytokines that activate the leukemia inhibitory factor receptor have been studied in the context of neurodegenerative disease, therapeutic targeting of the specific receptor subunit has been understudied in by comparison. This review examines the role of this receptor in the CNS and immune system, and its …

Minocycline Protects Developing Brain Against Ethanol-Induced Damage, Xin Wang, Kai Zhang, Fanmuyi Yang, Zhenhua Ren, Mei Xu, Jacqueline A. Frank, Zun-Ji Ke, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

Fetal alcohol spectrum disorders (FASD) are caused by ethanol exposure during the pregnancy and is the leading cause of mental retardation. Ethanol exposure during the development results in the loss of neurons in the developing brain, which may underlie many neurobehavioral deficits associated with FASD. It is important to understand the mechanisms underlying ethanol-induced neuronal loss and develop appropriate therapeutic strategies. One of the potential mechanisms involves neuroimmune activation. Using a third trimester equivalent mouse model of ethanol exposure, we demonstrated that ethanol induced a wide-spread neuroapoptosis, microglial activation, and neuroinflammation in C57BL/6 mice. Minocycline is an antibiotic that inhibits …

Beta-Catenin Cleavage Enhances Transcriptional Activation, Tatiana Goretsky, Emily M. Bradford, Qing Ye, Olivia F. Lamping, Tomas Vanagunas, Mary Pat Moyer, Patrick C. Keller, Preetika Sinh, Josep M. Llovet, Tianyan Gao, Qing-Bai She, Linheng Li, Terrence A. Barrett

Internal Medicine Faculty Publications

Nuclear activation of Wnt/β-catenin signaling is required for cell proliferation in inflammation and cancer. Studies from our group indicate that β-catenin activation in colitis and colorectal cancer (CRC) correlates with increased nuclear levels of β-catenin phosphorylated at serine 552 (pβ-Cat⁵⁵²). Biochemical analysis of nuclear extracts from cancer biopsies revealed the existence of low molecular weight (LMW) pβ-Cat⁵⁵², increased to the exclusion of full size (FS) forms of β-catenin. LMW β-catenin lacks both termini, leaving residues in the armadillo repeat intact. Further experiments showed that TCF4 predominantly binds LMW pβ-Cat⁵⁵² in the nucleus of inflamed and …

Disturbance Of Redox Homeostasis In Down Syndrome: Role Of Iron Dysmetabolism, Eugenio Barone, Andrea Arena, Elizabeth Head, D. Allan Butterfield, Marzia Perluigi

Sanders-Brown Center on Aging Faculty Publications

Down syndrome (DS) is the most common genetic form of intellectual disability that leads in the majority of cases to development of early-onset Alzheimer-like dementia (AD). The neuropathology of DS has several common features with AD including alteration of redox homeostasis, mitochondrial deficits, and inflammation among others. Interestingly, some of the genes encoded by chromosome 21 are responsible of increased oxidative stress (OS) conditions that are further exacerbated by decreased antioxidant defense. Previous studies from our groups showed that accumulation of oxidative damage is an early event in DS neurodegeneration and that oxidative modifications of selected proteins affects the integrity …

Down Syndrome, Beta-Amyloid And Neuroimaging, Elizabeth Head, Alex M. Helman, David K. Powell, Frederick A. Schmitt

Sanders-Brown Center on Aging Faculty Publications

This review focuses on the role of Aβ in AD pathogenesis in Down syndrome and current approaches for imaging Aβ in vivo. We will describe how Aβ deposits with age, the posttranslational modifications that can occur, and detection in biofluids. Three unique case studies describing partial trisomy 21 cases without APP triplication, and the occurrences of low level mosaic trisomy 21 in an early onset AD patient are presented. Brain imaging for Aβ includes those by positron emission tomography and ligands (Pittsburgh Compound B, Florbetapir, and FDDNP) that bind Aβ have been published and are summarized here. In combination, we …

Intra-Arterial Nitroglycerin As Directed Acute Treatment In Experimental Ischemic Stroke, Michael E. Maniskas, Jill M. Roberts, Rebecca Trueman, Annastazia E. Learoyd, Amanda A. Gorman, Justin F. Fraser, Gregory J. Bix

Neuroscience Faculty Publications

BACKGROUND: Nitroglycerin (also known as glyceryl trinitrate (GTN)), a vasodilator best known for treatment of ischemic heart disease, has also been investigated for its potential therapeutic benefit in ischemic stroke. The completed Efficacy of Nitric Oxide in Stroke trial suggested that GTN has therapeutic benefit with acute (within 6 hours) transdermal systemic sustained release therapy.

OBJECTIVE: To examine an alternative use of GTN as an acute therapy for ischemic stroke following successful recanalization.

METHODS: We administered GTN IA following transient middle cerebral artery occlusion in mice. Because no standard dose of GTN is available following emergent large vessel occlusion, we …

Tumor Suppressor Pdcd4 Attenuates Sin1 Translation To Inhibit Invasion In Colon Carcinoma, Qing Wang, Jiang Zhu, Ya-Wen Wang, Yong Dai, Yanlei Wang, Chi Wang, Jinpeng Liu, Alyson Baker, Nancy H. Colburn, Hsin-Sheng Yang

Toxicology and Cancer Biology Faculty Publications

Programmed cell death 4 (Pdcd4), a tumor invasion suppressor, is frequently downregulated in colorectal cancer and other cancers. In this study, we find that loss of Pdcd4 increases the activity of mammalian target of rapamycin complex 2 (mTORC2) and thereby upregulates Snail expression. Examining the components of mTORC2 showed that Pdcd4 knockdown increased the protein but not mRNA level of stress-activated-protein kinase interacting protein 1 (Sin1), which resulted from enhanced Sin1 translation. To understand how Pdcd4 regulates Sin1 translation, the SIN1 5′ untranslated region (5′UTR) was fused with luciferase reporter and named as 5′Sin1-Luc. Pdcd4 knockdown/knockout significantly increased the translation …

The Dual Role Of Group V Secretory Phospholipase A2 In Pancreatic Β-Cells, Preetha Shridas, Victoria P. Noffsinger, Andrea C. Trumbauer, Nancy R. Webb

Saha Cardiovascular Research Center Faculty Publications

Purpose

Group X (GX) and group V (GV) secretory phospholipase A₂ (sPLA₂) potently release arachidonic acid (AA) from the plasma membrane of intact cells. We previously demonstrated that GX sPLA₂ negatively regulates glucose-stimulated insulin secretion (GSIS) by a prostaglandin E2 (PGE2)-dependent mechanism. In this study we investigated whether GV sPLA₂ similarly regulates GSIS.

Methods

GSIS and pancreatic islet-size were assessed in wild-type (WT) and GV sPLA₂-knock out (GV KO) mice. GSIS was also assessed ex vivo in isolated islets and in vitro using MIN6 pancreatic beta cell lines with or without GV sPLA …

The Trophic Life Cycle Stage Of The Opportunistic Fungal Pathogen Pneumocystis Murina Hinders The Ability Of Dendritic Cells To Stimulate Cd4+ T Cell Responses, Heather M. Evans, Andrew Simpson, Shu Shen, Arnold J. Stromberg, Carol L. Pickett, Beth A. Garvy

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The life cycle of the opportunistic fungal pathogen Pneumocystis murina consists of a trophic stage and an ascus-like cystic stage. Infection with the cyst stage induces proinflammatory immune responses, while trophic forms suppress the cytokine response to multiple pathogen-associated molecular patterns (PAMPs), including β-glucan. A targeted gene expression assay was used to evaluate the dendritic cell response following stimulation with trophic forms alone, with a normal mixture of trophic forms and cysts, or with β-glucan. We demonstrate that stimulation with trophic forms downregulated the expression of multiple genes normally associated with the response to infection, including genes encoding …

Loss Of Fructose-1,6-Bisphosphatase Induces Glycolysis And Promotes Apoptosis Resistance Of Cancer Stem-Like Cells: An Important Role In Hexavalent Chromium-Induced Carcinogenesis, Jin Dai, Yanli Ji, Wei Wang, Donghern Kim, Leonard Yenwong Fai, Lei Wang, Jia Luo, Zhuo Zhang

Toxicology and Cancer Biology Faculty Publications

Hexavalent chromium (Cr(VI)) compounds are confirmed human carcinogens for lung cancer. Our previous studies has demonstrated that chronic exposure of human bronchial epithelial BEAS-2B cells to low dose of Cr(VI) causes malignant cell transformation. The acquisition of cancer stem cell-like properties is involved in the initiation of cancers. The present study has observed that a small population of cancer stem-like cells (BEAS-2B-Cr-CSC) exists in the Cr(VI)-transformed cells (BEAS-2B-Cr). Those BEAS-2B-Cr-CSC exhibit extremely reduced capability of generating reactive oxygen species (ROS) and apoptosis resistance. BEAS-2B-Cr-CSC are metabolic inactive as evidenced by reductions in oxygen consumption, glucose uptake, ATP production, and lactate …

Probing The Metabolic Phenotype Of Breast Cancer Cells By Multiple Tracer Stable Isotope Resolved Metabolomics, Andrew N. Lane, Julie Tan, Yali Wang, Jun Yan, Richard M. Higashi, Teresa W. -M. Fan

Center for Environmental and Systems Biochemistry Faculty Publications

Breast cancers vary by their origin and specific set of genetic lesions, which gives rise to distinct phenotypes and differential response to targeted and untargeted chemotherapies. To explore the functional differences of different breast cell types, we performed Stable Isotope Resolved Metabolomics (SIRM) studies of one primary breast (HMEC) and three breast cancer cells (MCF-7, MDAMB-231, and ZR75-1) having distinct genotypes and growth characteristics, using ¹³C₆-glucose, ¹³C-1+2-glucose, ¹³C₅,¹⁵N₂-Gln, ¹³C₃-glycerol, and ¹³C₈-octanoate as tracers. These tracers were designed to probe the central energy producing …

Thiamine Deficiency And Neurodegeneration: The Interplay Among Oxidative Stress, Endoplasmic Reticulum Stress, And Autophagy, Dexiang Liu, Zunji Ke, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

Thiamine (vitamin B1) is an essential nutrient and indispensable for normal growth and development of the organism due to its multilateral participation in key biochemical and physiological processes. Humans must obtain thiamine from their diet since it is synthesized only in bacteria, fungi, and plants. Thiamine deficiency (TD) can result from inadequate intake, increased requirement, excessive deletion, and chronic alcohol consumption. TD affects multiple organ systems, including the cardiovascular, muscular, gastrointestinal, and central and peripheral nervous systems. In the brain, TD causes a cascade of events including mild impairment of oxidative metabolism, neuroinflammation, and neurodegeneration, which are commonly observed in …

Abl Kinase Regulation By Braf/Erk And Cooperation With Akt In Melanoma, Aditi Jain, Rakshamani Tripathi, Courtney P. Turpin, Chi Wang, Rina Plattner

Pharmacology and Nutritional Sciences Faculty Publications

The melanoma incidence continues to increase, and the disease remains incurable for many due to its metastatic nature and high rate of therapeutic resistance. In particular, melanomas harboring BRAF^V600E and PTEN mutations often are resistant to current therapies, including BRAF inhibitors (BRAFi) and immune checkpoint inhibitors. Abl kinases (Abl/Arg) are activated in melanomas and drive progression; however, their mechanism of activation has not been established. Here we elucidate a novel link between BRAF^V600E/ERK signaling and Abl kinases. We demonstrate that BRAF^V600E/ERK play a critical role in binding, phosphorylating and regulating Abl localization and Abl/Arg activation …

Targeting Hepatic Heparin-Binding Egf-Like Growth Factor (Hb-Egf) Induces Anti-Hyperlipidemia Leading To Reduction Of Angiotensin Ii-Induced Aneurysm Development, Seonwook Kim, Lihua Yang, Seongu Kim, Richard G. Lee, Mark J. Graham, Judith A. Berliner, Aldons J. Lusis, Lei Cai, Ryan E. Temel, Debra L. Rateri, Sangderk Lee

Saha Cardiovascular Research Center Faculty Publications

Objective

The upregulated expression of heparin binding EGF-like growth factor (HB-EGF) in the vessel and circulation is associated with risk of cardiovascular disease. In this study, we tested the effects of HB-EGF targeting using HB-EGF-specific antisense oligonucleotide (ASO) on the development of aortic aneurysm in a mouse aneurysm model.

Approach and results

Low-density lipoprotein receptor (LDLR) deficient mice (male, 16 weeks of age) were injected with control and HB-EGF ASOs for 10 weeks. To induce aneurysm, the mice were fed a high fat diet (22% fat, 0.2% cholesterol; w/w) at 5 week point of ASO administration and infused with angiotensin …

Brain Microvascular Injury And White Matter Disease Provoked By Diabetes-Associated Hyperamylinemia, Han Ly, Nirmal Verma, Fengen Wu, Miao Liu, Kathryn E. Saatman, Peter T. Nelson, John T. Slevin, Larry B. Goldstein, Geert Jan Biessels, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

OBJECTIVE: The brain blood vessels of patients with type 2 diabetes and dementia have deposition of amylin, an amyloidogenic hormone cosecreted with insulin. It is not known whether vascular amylin deposition is a consequence or a trigger of vascular injury. We tested the hypothesis that the vascular amylin deposits cause endothelial dysfunction and microvascular injury and are modulated by amylin transport in the brain via plasma apolipoproteins.

METHODS: Rats overexpressing amyloidogenic (human) amylin in the pancreas (HIP rats) and amylin knockout (AKO) rats intravenously infused with aggregated amylin were used for in vivo phenotyping. We also carried out biochemical analyses …

Peripheral Inflammation, Apolipoprotein E4, And Amyloid-Β Interact To Induce Cognitive And Cerebrovascular Dysfunction, Felecia M. Marottoli, Yuriko Katsumata, Kevin P. Koster, Riya Thomas, David W. Fardo, Leon M. Tai

Biostatistics Faculty Publications

Cerebrovascular dysfunction is rapidly reemerging as a major process of Alzheimer’s disease (AD). It is, therefore, crucial to delineate the roles of AD risk factors in cerebrovascular dysfunction. While apolipoprotein E4 (APOE4), Amyloid-β (Aβ), and peripheral inflammation independently induce cerebrovascular damage, their collective effects remain to be elucidated. The goal of this study was to determine the interactive effect of APOE4, Aβ, and chronic repeated peripheral inflammation on cerebrovascular and cognitive dysfunction in vivo. EFAD mice are a well-characterized mouse model that express human APOE3 (E3FAD) or APOE4 (E4FAD) and overproduce human Aβ42 via expression of …

Targeting Antioxidant Enzyme Expression As A Therapeutic Strategy For Ischemic Stroke, Stephanie M. Davis, Keith R. Pennypacker

Center for Advanced Translational Stroke Science Faculty Publications

During ischemic stroke, neurons and glia are subjected to damage during the acute and neuroinflammatory phases of injury. Production of reactive oxygen species (ROS) from calcium dysregulation in neural cells and the invasion of activated immune cells are responsible for stroke-induced neurodegeneration. Scientists have failed thus far to identify antioxidant-based drugs that can enhance neural cell survival and improve recovery after stroke. However, several groups have demonstrated success in protecting against stroke by increasing expression of antioxidant enzymes in neural cells. These enzymes, which include but are not limited to enzymes in the glutathione peroxidase, catalase, and superoxide dismutase families, …

Nfatc2 Modulates Microglial Activation In The Aβpp/Ps1 Mouse Model Of Alzheimer's Disease, Gunjan D. Manocha, Atreyi Ghatak, Kendra L. Puig, Susan D. Kraner, Christopher M. Norris, Colin K. Combs

Pharmacology and Nutritional Sciences Faculty Publications

Alzheimer’s disease (AD) brains are characterized by fibrillar amyloid-β (Aβ) peptide containing plaques and associated reactive microglia. The proinflammatory phenotype of the microglia suggests that they may negatively affect disease course and contribute to behavioral decline. This hypothesis predicts that attenuating microglial activation may provide benefit against disease. Prior work from our laboratory and others has characterized a role for the transcription factor, nuclear factor of activated T cells (NFAT), in regulating microglial phenotype in response to different stimuli, including Aβ peptide. We observed that the NFATc2 isoform was the most highly expressed in murine microglia cultures, and inhibition or …

Zinc Transporters Ybtx And Znuabc Are Required For The Virulence Of Yersinia Pestis In Bubonic And Pneumonic Plague In Mice, Alexander G. Bobrov, Olga Kirillina, Marina Y. Fosso, Jacqueline D. Fetherston, M. Clarke Miller, Tiva T. Vancleave, Joseph A. Burlison, William K. Arnold, Matthew B. Lawrenz, Sylvie Garneau-Tsodikova, Robert D. Perry

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A number of bacterial pathogens require the ZnuABC Zinc (Zn²⁺) transporter and/or a second Zn²⁺ transport system to overcome Zn²⁺ sequestration by mammalian hosts. Previously we have shown that in addition to ZnuABC, Yersinia pestis possesses a second Zn²⁺ transporter that involves components of the yersiniabactin (Ybt), siderophore-dependent iron transport system. Synthesis of the Ybt siderophore and YbtX, a member of the major facilitator superfamily, are both critical components of the second Zn²⁺ transport system. Here we demonstrate that a ybtX znu double mutant is essentially avirulent in mouse models of bubonic and pneumonic …

Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair

Toxicology and Cancer Biology Faculty Publications

Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced …