Digital Commons Network^™

Sr-A Ligand And M-Csf Dynamically Regulate Sr-A Expression And Function In Primary Macrophages Via P38 Mapk Activation, Dejan Nikolic, Lindsay Calderon, Liqin Du, Steven R. Post

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Inflammation is characterized by dynamic changes in the expression of cytokines, such as M-CSF, and modifications of lipids and proteins that result in the formation of ligands for Class A Scavenger Receptors (SR-A). These changes are associated with altered SR-A expression in macrophages; however, the intracellular signal pathways involved and the extent to which SR-A ligands regulate SR-A expression are not well defined. To address these questions, SR-A expression and function were examined in resident mouse peritoneal macrophages incubated with M-CSF or the selective SR-A ligand acetylated-LDL (AcLDL).

RESULTS: M-CSF increased SR-A expression and function, and required the specific …

Identification Of Factors Associated With Good Response To Growth Hormone Therapy In Children With Short Stature: Results From The Answer Program®., Peter A Lee, John Germak, Robert Gut, Naum Khutoryansky, Judith Ross

Department of Pediatrics Faculty Papers

UNLABELLED: ABSTRACT:

OBJECTIVE: To identify factors associated with growth in children on growth hormone (GH) therapy using data from the American Norditropin Studies: Web-enabled Research (ANSWER) Program® registry.

METHODS: GH-naïve children with GH deficiency, multiple pituitary hormone deficiency, idiopathic short stature, Turner syndrome, or a history of small for gestational age were eligible (N = 1,002). Using a longitudinal statistical approach, predictive factors were identified in patients with GHD for change from baseline in height standard deviation score (ΔHSDS) following 2 years of treatment.

RESULTS: Gradual increases in ΔHSDS over time were observed for all diagnostic categories. Significant predictive factors …

Merging Resource Availability With Isotope Mixing Models: The Role Of Neutral Interaction Assumptions, Justin D. Yeakel, Mark Novak, Paulo R. Guimarães, Nathaniel J. Dominy, Paul L. Koch, Eric J. Ward, Jonathan W. Moore, Brice X. Semmens

Dartmouth Scholarship

Bayesian mixing models have allowed for the inclusion of uncertainty and prior information in the analysis of trophic interactions using stable isotopes. Formulating prior distributions is relatively straightforward when incorporating dietary data. However, the use of data that are related, but not directly proportional, to diet (such as prey availability data) is often problematic because such information is not necessarily predictive of diet, and the information required to build a reliable prior distribution for all prey species is often unavailable. Omitting prey availability data impacts the estimation of a predator's diet and introduces the strong assumption of consumer ultrageneralism (where …

Oncogene-Induced Nrf2 Transcription Promotes Ros Detoxification And Tumorigenesis., Gina M. Denicola, Florian A. Karreth, Timothy J. Humpton, Aarthi Gopinathan, Cong Wei, Kristopher Frese, Dipti Mangal, Kenneth H. Yu, Charles J. Yeo, Eric S. Calhoun, Francesca Scrimieri, Jordan M. Winter, Ralph H. Hruban, Christine Iacobuzio-Donahue, Scott E. Kern, Ian A Blair, David A. Tuveson

Department of Surgery Faculty Papers

Reactive oxygen species (ROS) are mutagenic and may thereby promote cancer. Normally, ROS levels are tightly controlled by an inducible antioxidant program that responds to cellular stressors and is predominantly regulated by the transcription factor Nrf2 (also known as Nfe2l2) and its repressor protein Keap1 (refs 2-5). In contrast to the acute physiological regulation of Nrf2, in neoplasia there is evidence for increased basal activation of Nrf2. Indeed, somatic mutations that disrupt the Nrf2-Keap1 interaction to stabilize Nrf2 and increase the constitutive transcription of Nrf2 target genes were recently identified, indicating that enhanced ROS detoxification and additional Nrf2 functions may …

Microglial P38Α Mapk Is A Key Regulator Of Proinflammatory Cytokine Up-Regulation Induced By Toll-Like Receptor (Tlr) Ligands Or Beta-Amyloid (Aβ), Adam D. Bachstetter, Bin Xing, Lucia De Almeida, Edgardo R. Dimayuga, D. Martin Watterson, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Overproduction of proinflammatory cytokines from activated microglia has been implicated as an important contributor to pathophysiology progression in both acute and chronic neurodegenerative diseases. Therefore, it is critical to elucidate intracellular signaling pathways that are significant contributors to cytokine overproduction in microglia exposed to specific stressors, especially pathways amenable to drug interventions. The serine/threonine protein kinase p38α MAPK is a key enzyme in the parallel and convergent intracellular signaling pathways involved in stressor-induced production of IL-1β and TNFα in peripheral tissues, and is a drug development target for peripheral inflammatory diseases. However, much less is known about the quantitative …

Ethanol Enhances Neurosteroidogenesis In Hippocampal Pyramidal Neurons By Paradoxical Nmda Receptor Activation, Kazuhiro Tokuda, Yukitoshi Izumi, Charles F. Zorumski

Open Access Publications

Using an antibody against 5α-reduced neurosteroids, predominantly allopregnanolone, we found that immunostaining in the CA1 region of rat hippocampal slices was confined to pyramidal neurons. This neurosteroid staining was increased following 15 min administration of 60 mm but not 20 mm ethanol, and the enhancement was blocked by finasteride and dutasteride, selective inhibitors of 5α-reductase, a key enzyme required for allopregnanolone synthesis. Consistent with a prior report indicating that N-methyl-D-aspartate (NMDA) receptor (NMDAR) activation can promote steroid production, we observed that D-2-amino-5-phosphonovalerate (APV), a competitive NMDAR antagonist, blocked the effects of 60 mm ethanol on staining. We previously reported that …

Ceacam1 Separates Graft-Versus-Host-Disease From Graft-Versus-Tumor Activity After Experimental Allogeneic Bone Marrow Transplantation., Sydney X Lu, Lucy W Kappel, Anne-Marie Charbonneau-Allard, Renée Atallah, Amanda M Holland, Claire Turbide, Vanessa M Hubbard, Jimmy A Rotolo, Marsinay Smith, David Suh, Christopher King, Uttam K Rao, Nury Yim, Johanne L Bautista, Robert R Jenq, Olaf Penack, Il-Kang Na, Chen Liu, George Murphy, Onder Alpdogan, Richard S Blumberg, Fernando Macian, Kathryn V Holmes, Nicole Beauchemin, Marcel R M Van Den Brink

Department of Medical Oncology Faculty Papers

BACKGROUND: Allogeneic bone marrow transplantation (allo-BMT) is a potentially curative therapy for a variety of hematologic diseases, but benefits, including graft-versus-tumor (GVT) activity are limited by graft-versus-host-disease (GVHD). Carcinoembryonic antigen related cell adhesion molecule 1 (Ceacam1) is a transmembrane glycoprotein found on epithelium, T cells, and many tumors. It regulates a variety of physiologic and pathological processes such as tumor biology, leukocyte activation, and energy homeostasis. Previous studies suggest that Ceacam1 negatively regulates inflammation in inflammatory bowel disease models.

METHODS: We studied Ceacam1 as a regulator of GVHD and GVT after allogeneic bone marrow transplantation (allo-BMT) in mouse models. In …

Gene Set Analysis For Longitudinal Gene Expression Data, Ke Zhang, Haiyan Wang, Arne C. Bathke, Solomon W. Harrar, Hans-Peter Piepho, Youping Deng

Statistics Faculty Publications

BACKGROUND: Gene set analysis (GSA) has become a successful tool to interpret gene expression profiles in terms of biological functions, molecular pathways, or genomic locations. GSA performs statistical tests for independent microarray samples at the level of gene sets rather than individual genes. Nowadays, an increasing number of microarray studies are conducted to explore the dynamic changes of gene expression in a variety of species and biological scenarios. In these longitudinal studies, gene expression is repeatedly measured over time such that a GSA needs to take into account the within-gene correlations in addition to possible between-gene correlations.

RESULTS: We provide …

The Eagleville Times,Volume 9, Issue 7, Debbie Ryan

Eagleville Times

No abstract provided.

Effects Of Xenobiotics And Phytotoxins On Reproduction In Food Animals, Kip E. Panter, Bryan L. Stegelmeier

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The influence of natural toxicants and anthropogenic compounds on reproduction in food animals is significant in its economic impact, and the subject requires more research and further experimental substantiation. Confounding factors such as stress, nutritional status, season of the year, animal species involved, genetic variability, disease conditions, management factors, and so forth exacerbate the difficulty of making an accurate diagnosis and thereby may impede progress to improve reproductive performance on an individual operation. The interaction between the reproductive system and xenobiotics (reproductive toxicology) is a relatively new area of study and a subject of increasing interest, especially in the area …

Controlled Cortical Impact Traumatic Brain Injury In 3xtg-Ad Mice Causes Acute Intra-Axonal Amyloid-Β Accumulation And Independently Accelerates The Development Of Tau Abnormalities, Hien T. Tran, Frank M. Laferla, David M. Holtzman, David L. Brody

Open Access Publications

Alzheimer's disease (AD) is a neurodegenerative disorder characterized pathologically by progressive neuronal loss, extracellular plaques containing the amyloid-β (Aβ) peptides, and neurofibrillary tangles composed of hyperphosphorylated tau proteins. Aβ is thought to act upstream of tau, affecting its phosphorylation and therefore aggregation state. One of the major risk factors for AD is traumatic brain injury (TBI). Acute intra-axonal Aβ and diffuse extracellular plaques occur in ∼30% of human subjects after severe TBI. Intra-axonal accumulations of tau but not tangle-like pathologies have also been found in these patients. Whether and how these acute accumulations contribute to subsequent AD development is not …

Identification Of The Allosteric Regulatory Site Of Insulysin, Nicholas Noinaj, Sonia K. Bhasin, Eun Suk Song, Kirsten E. Scoggin, Maria A. Juliano, Luiz Juliano, Louis B. Hersh, David W. Rodgers

Molecular and Cellular Biochemistry Faculty Publications

BACKGROUND: Insulin degrading enzyme (IDE) is responsible for the metabolism of insulin and plays a role in clearance of the Aβ peptide associated with Alzheimer's disease. Unlike most proteolytic enzymes, IDE, which consists of four structurally related domains and exists primarily as a dimer, exhibits allosteric kinetics, being activated by both small substrate peptides and polyphosphates such as ATP.

PRINCIPAL FINDINGS: The crystal structure of a catalytically compromised mutant of IDE has electron density for peptide ligands bound at the active site in domain 1 and a distal site in domain 2. Mutating residues in the distal site eliminates allosteric …

Sonic Hedgehog Dependent Phosphorylation By Ck1Α And Grk2 Is Required For Ciliary Accumulation And Activation Of Smoothened, Yongbin Chen, Noriaki Sasai, Guoqiang Ma, Tao Yue, Jianhang Jia, James Briscoe, Jin Jiang

Markey Cancer Center Faculty Publications

Hedgehog (Hh) signaling regulates embryonic development and adult tissue homeostasis through the GPCR-like protein Smoothened (Smo), but how vertebrate Smo is activated remains poorly understood. In Drosophila, Hh dependent phosphorylation activates Smo. Whether this is also the case in vertebrates is unclear, owing to the marked sequence divergence between vertebrate and Drosophila Smo (dSmo) and the involvement of primary cilia in vertebrate Hh signaling. Here we demonstrate that mammalian Smo (mSmo) is activated through multi-site phosphorylation of its carboxyl-terminal tail by CK1α and GRK2. Phosphorylation of mSmo induces its active conformation and simultaneously promotes its ciliary accumulation. We demonstrate that …

Cooperative And Antagonistic Contributions Of Two Heterochromatin Proteins To Transcriptional Regulation Of The Drosophila Sex Determination Decision, Hui Li, Janel Rodriguez, Youngdong Yoo, Momin Mohammed Shareef, Ramakrishna Badugu, Jamila I. Horabin, Rebecca Kellum

Biology Faculty Publications

Eukaryotic nuclei contain regions of differentially staining chromatin (heterochromatin), which remain condensed throughout the cell cycle and are largely transcriptionally silent. RNAi knockdown of the highly conserved heterochromatin protein HP1 in Drosophila was previously shown to preferentially reduce male viability. Here we report a similar phenotype for the telomeric partner of HP1, HOAP, and roles for both proteins in regulating the Drosophila sex determination pathway. Specifically, these proteins regulate the critical decision in this pathway, firing of the establishment promoter of the masterswitch gene, Sex-lethal (Sxl). Female-specific activation of this promoter, Sxl(Pe), is essential to females, as it provides SXL …

Store-Operated Ca(2+) Entry (Soce) Contributes To Normal Skeletal Muscle Contractility In Young But Not In Aged Skeletal Muscle, Angela M. Thornton, Xiaoli Zhao, Noah Weisleder, Leticia S. Brotto, Sylvain Bougoin, Thomas M. Nosek, Michael B. Reid, Brian Hardin, Zui Pan, Jianjie Ma, Jerome Parness, Marco Brotto

Physiology Faculty Publications

Muscle atrophy alone is insufficient to explain the significant decline in contractile force of skeletal muscle during normal aging. One contributing factor to decreased contractile force in aging skeletal muscle could be compromised excitation-contraction (E-C) coupling, without sufficient available Ca(2+) to allow for repetitive muscle contractility, skeletal muscles naturally become weaker. Using biophysical approaches, we previously showed that store-operated Ca(2+) entry (SOCE) is compromised in aged skeletal muscle but not in young ones. While important, a missing component from previous studies is whether or not SOCE function correlates with contractile function during aging. Here we test the contribution of extracellular …

Role Of Guanylyl Cyclase Modulation In Mouse Cone Phototransduction, Keisuke Sakurai, Jeannie Chen, Vladimir J. Kefalov

Open Access Publications

A negative phototransduction feedback in rods and cones is critical for the timely termination of their light responses and for extending their function to a wide range of light intensities. The calcium feedback mechanisms that modulate phototransduction in rods have been studied extensively. However, the corresponding modulation mechanisms that enable cones to terminate rapidly their light responses and to adapt in bright light, properties critical for our daytime vision, are still not understood. In cones, calcium feedback to guanylyl cyclase is potentially a key step in phototransduction modulation. The guanylyl cyclase activity is modulated by the calcium-binding guanylyl cyclase activating …

Soluble Extract From The Nematode Strongyloides Stercoralis Induces Cxcr2 Dependent/Il-17 Independent Neutrophil Recruitment., Amy E. O'Connell, Kevin Redding, Jessica A. Hess, James B. Lok, Thomas J. Nolan, David Abraham

Department of Microbiology and Immunology Faculty Papers

Neutrophil recruitment via CXCR2 is required for innate and adaptive protective immunity to the larvae of Strongyloides stercoralis in mice. The goal of the present study was to determine the mechanism of CXCR2-mediated neutrophil recruitment to S. stercoralis. Mice deficient in the receptor for IL-17A and IL-17F, upstream mediators of CXCR2 ligand production, were infected with S. stercoralis larvae; there was no difference in larval survival, neutrophil recruitment, or production of CXCR2 ligands compared with wild type mice. In vivo and in vitro stimulation of neutrophils with S. stercoralis soluble extract resulted in significant neutrophil recruitment. In vitro assays demonstrated …

The Eagleville Times,Volume 9, Issue 6, Debbie Ryan

Eagleville Times

No abstract provided.

Role Of Phosphoinositide 3-Kinase – Akt Signaling Pathway In The Age-Related Cytokine Dysregulation In Splenic Macrophages Stimulated Via Tlr-2 Or Tlr-4 Receptors, Mosoka Papa Fallah, R. Lakshman Chelvarajan, Beth A. Garvy, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Age-associated defects in both B-lymphocytes and macrophages in elderly result in a reduction in the efficacy of vaccines to many Gram positive bacteria like Streptococcus pneumoniae. Splenic macrophages from aged mice have been shown to have a defect in production of pro-inflammatory cytokines (IL-6, IL-12, IL-1β, TNF-α) but exhibit increased production of IL-10 upon TLR4 ligation. Here we showed that aged macrophages demonstrate similar cytokine dysregulation phenotype upon stimulation with TLR2 ligands, or killed S. pneumoniae. We hypothesized that an age-associated increase in activity of phosphatidyl inositol 3-kinase (PI3K)-Akt signaling pathway may be playing a causal role in …

Profound Early Control Of Highly Pathogenic Siv By An Effector Memory T-Cell Vaccine., Scott G. Hansen, Julia C. Ford, Matthew S. Lewis, Abigail B. Ventura, Colette M. Hughes, Lia Coyne-Johnson, Nathan Whizin, Kelli Oswald, Rebecca Shoemaker, Tonya Swanson, Alfred W. Legasse, Maria J. Chiuchiolo, Christopher L. Parks, Michael K. Axthelm, Jay A. Nelson, Michael A. Jarvis, Michael Piatak, Jeffrey D. Lifson, Louis J. Picker

School of Biomedical Sciences

The acquired immunodeficiency syndrome (AIDS)-causing lentiviruses human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) effectively evade host immunity and, once established, infections with these viruses are only rarely controlled by immunological mechanisms. However, the initial establishment of infection in the first few days after mucosal exposure, before viral dissemination and massive replication, may be more vulnerable to immune control. Here we report that SIV vaccines that include rhesus cytomegalovirus (RhCMV) vectors establish indefinitely persistent, high-frequency, SIV-specific effector memory T-cell (T(EM)) responses at potential sites of SIV replication in rhesus macaques and stringently control highly pathogenic SIV(MAC239) infection early after …

Mitochondrial Oxidative Stress Drives Tumor Progression And Metastasis: Should We Use Antioxidants As A Key Component Of Cancer Treatment And Prevention?, Federica Sotgia, Ubaldo E Martinez-Outschoorn, Michael P Lisanti

Department of Stem Cell Biology and Regenerative Medicine Faculty Papers & Presentations

The functional role of oxidative stress in cancer pathogenesis has long been a hotly debated topic. A study published this month in BMC Cancer by Goh et al., directly addresses this issue by using a molecular genetic approach, via an established mouse animal model of human breast cancer. More specifically, alleviation of mitochondrial oxidative stress, via transgenic over-expression of catalase (an anti-oxidant enzyme) targeted to mitochondria, was sufficient to lower tumor grade (from high-to-low) and to dramatically reduce metastatic tumor burden by >12-fold. Here, we discuss these new findings and place them in the context of several other recent studies …

Controlling The Activity Of A Phosphatase And Tensin Homolog (Pten) By Membrane Potential, Jérôme J. Lacroix, Christian R. Halaszovich, Daniela N. Schreiber, Michael G. Leitner, Francisco Bezanilla, Dominik Oliver, Carlos A. Villalba-Galea

School of Pharmacy Faculty Articles

The recently discovered voltage-sensitive phosphatases (VSPs) hydrolyze phosphoinositides upon depolarization of the membrane potential, thus representing a novel principle for the transduction of electrical activity into biochemical signals. Here, we demonstrate the possibility to confer voltage sensitivity to cytosolic enzymes. By fusing the tumor suppressor PTEN to the voltage sensor of the prototypic VSP from Ciona intestinalis, Ci-VSP, we generated chimeric proteins that are voltage-sensitive and display PTEN-like enzymatic activity in a strictly depolarization-dependent manner in vivo. Functional coupling of the exogenous enzymatic activity to the voltage sensor is mediated by a phospholipid-binding motif at the interface between voltage sensor …

Lipid Phosphate Phosphatase 3 Enables Efficient Thymic Egress, Béatrice Bréart, Willy D. Ramos-Perez, Alejandra Mendoza, Abdelghaffar K. Salous, Michael Gobert, Yong Huang, Ralf H. Adams, Juan J. Lafaille, Diana Escalante-Alcalde, Andrew J. Morris, Susan R. Schwab

Gill Heart & Vascular Institute Faculty Publications

The signaling lipid sphingosine-1-phosphate (S1P) stabilizes the vasculature, directs lymphocyte egress from lymphoid organs, and shapes inflammatory responses. However, little is known about how S1P distribution is controlled in vivo, and it is not clear how a ubiquitously made lipid functions as a signal that requires precise spatial and temporal control. We have found that lipid phosphate phosphatase 3 (LPP3) enables efficient export of mature T cells from the thymus into circulation, and several lines of evidence suggest that LPP3 promotes exit by destroying thymic S1P. Although five additional S1P-degrading enzymes are expressed in the thymus, they cannot compensate for …

Digeorge Critical Region 8 (Dgcr8) Is A Double-Cysteine-Ligated Heme Protein., Ian Barr, Aaron T. Smith, Rachel Senturia, Yanqiu Chen, Brooke D. Scheidemantle, Judith N. Burstyn, Feng Guo

Natural Sciences and Mathematics | Faculty Scholarship

All known heme-thiolate proteins ligate the heme iron using one cysteine side chain. We previously found that DiGeorge Critical Region 8 (DGCR8), an essential microRNA processing factor, associates with heme of unknown redox state when overexpressed in Escherichia coli. On the basis of the similarity of the 450-nm Soret absorption peak of the DGCR8-heme complex to that of cytochrome P450 containing ferrous heme with CO bound, we identified cysteine 352 as a probable axial ligand in DGCR8. Here we further characterize the DGCR8-heme interaction using biochemical and spectroscopic methods. The DGCR8-heme complex is highly stable, with a half-life exceeding 4 …

Nogo-B Receptor Is Necessary For Cellular Dolichol Biosynthesis And Protein N-Glycosylation., Kenneth D Harrison, Eon Joo Park, Ningguo Gao, Andrew Kuo, Jeffrey S. Rush, Charles J Waechter, Mark A Lehrman, William C Sessa

Molecular and Cellular Biochemistry Faculty Publications

Dolichol monophosphate (Dol-P) functions as an obligate glycosyl carrier lipid in protein glycosylation reactions. Dol-P is synthesized by the successive condensation of isopentenyl diphosphate (IPP), with farnesyl diphosphate catalysed by a cis-isoprenyltransferase (cis-IPTase) activity. Despite the recognition of cis-IPTase activity 40 years ago and the molecular cloning of the human cDNA encoding the mammalian enzyme, the molecular machinery responsible for regulating this activity remains incompletely understood. Here, we identify Nogo-B receptor (NgBR) as an essential component of the Dol-P biosynthetic machinery. Loss of NgBR results in a robust deficit in cis-IPTase activity and Dol-P production, leading to diminished levels of …

Septin Filaments Exhibit A Dynamic, Paired Organization That Is Conserved From Yeast To Mammals, Bradley S. Demay, Xiaobo Bai, Louisa Howard, Patricia Occhipinti, Rebecca A. Meseroll, Elias T. Spiliotis, Rudolf Oldenbourg, Amy S. Gladfelter

Dartmouth Scholarship

The septins are conserved, GTP-binding proteins important for cytokinesis, membrane compartmentalization, and exocytosis. However, it is unknown how septins are arranged within higher-order structures in cells. To determine the organization of septins in live cells, we developed a polarized fluorescence microscopy system to monitor the orientation of GFP dipole moments with high spatial and temporal resolution. When GFP was fused to septins, the arrangement of GFP dipoles reflected the underlying septin organization. We demonstrated in a filamentous fungus, a budding yeast, and a mammalian epithelial cell line that septin proteins were organized in an identical highly ordered fashion. Fluorescence anisotropy …

Synaptic Reorganization Of Inhibitory Hilar Interneuron Circuitry After Traumatic Brain Injury In Mice, Robert F. Hunt, Stephen W. Scheff, Bret N. Smith

Physiology Faculty Publications

Functional plasticity of synaptic networks in the dentate gyrus has been implicated in the development of posttraumatic epilepsy and in cognitive dysfunction after traumatic brain injury, but little is known about potentially pathogenic changes in inhibitory circuits. We examined synaptic inhibition of dentate granule cells and excitability of surviving GABAergic hilar interneurons 8–13 weeks after cortical contusion brain injury in transgenic mice that express enhanced green fluorescent protein in a subpopulation of inhibitory neurons. Whole-cell voltage-clamp recordings in granule cells revealed a reduction in spontaneous and miniature IPSC frequency after head injury; no concurrent change in paired-pulse ratio was found …

A Positive Feedback Synapse From Retinal Horizontal Cells To Cone Photoreceptors., Skyler L. Jackman, Norbert Babai, James J. Chambers, Wallace B. Thoreson, Richard H. Kramer

Journal Articles: Ophthalmology

Cone photoreceptors and horizontal cells (HCs) have a reciprocal synapse that underlies lateral inhibition and establishes the antagonistic center-surround organization of the visual system. Cones transmit to HCs through an excitatory synapse and HCs feed back to cones through an inhibitory synapse. Here we report that HCs also transmit to cone terminals a positive feedback signal that elevates intracellular Ca(2+) and accelerates neurotransmitter release. Positive and negative feedback are both initiated by AMPA receptors on HCs, but positive feedback appears to be mediated by a change in HC Ca(2+), whereas negative feedback is mediated by a change in HC membrane …

The Interplay Between Nf-Kappab And E2f1 Coordinately Regulates Inflammation And Metabolism In Human Cardiac Cells., Xavier Palomer, David Álvarez-Guardia, Mercy M Davidson, Tung O Chan, Arthur M Feldman, Manuel Vázquez-Carrera

Department of Medicine Faculty Papers

Pyruvate dehydrogenase kinase 4 (PDK4) inhibition by nuclear factor-κB (NF-κB) is related to a shift towards increased glycolysis during cardiac pathological processes such as cardiac hypertrophy and heart failure. The transcription factors estrogen-related receptor-α (ERRα) and peroxisome proliferator-activated receptor (PPAR) regulate PDK4 expression through the potent transcriptional coactivator PPARγ coactivator-1α (PGC-1α). NF-κB activation in AC16 cardiac cells inhibit ERRα and PPARβ/δ transcriptional activity, resulting in reduced PGC-1α and PDK4 expression, and an enhanced glucose oxidation rate. However, addition of the NF-κB inhibitor parthenolide to these cells prevents the downregulation of PDK4 expression but not ERRα and PPARβ/δ DNA binding activity, …

The Eagleville Times,Volume 9, Issue 5, Debbie Ryan

Eagleville Times

No abstract provided.