Medicine and Health Sciences Commons^™

Conformational Motions And Ligand-Binding Underlying Gating And Regulation In Ip3r Channel, Guizhen Fan, Mariah R Baker, Lara E Terry, Vikas Arige, Muyuan Chen, Alexander B Seryshev, Matthew L Baker, Steven J Ludtke, David I Yule, Irina I Serysheva

Journal Articles

Inositol-1,4,5-trisphosphate receptors (IP3Rs) are activated by IP3 and Ca2+ and their gating is regulated by various intracellular messengers that finely tune the channel activity. Here, using single particle cryo-EM analysis we determined 3D structures of the nanodisc-reconstituted IP3R1 channel in two ligand-bound states. These structures provide unprecedented details governing binding of IP3, Ca2+ and ATP, revealing conformational changes that couple ligand-binding to channel opening. Using a deep-learning approach and 3D variability analysis we extracted molecular motions of the key protein domains from cryo-EM density data. We find that IP3 binding relies upon intrinsic flexibility of the ARM2 domain in the …

Capture At The Er-Mitochondrial Contacts Licenses Ip, Máté Katona, Ádám Bartók, Zuzana Nichtova, György Csordás, Elena Berezhnaya, David Weaver, Arijita Ghosh, Péter Várnai, David I. Yule, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Endoplasmic reticulum-mitochondria contacts (ERMCs) are restructured in response to changes in cell state. While this restructuring has been implicated as a cause or consequence of pathology in numerous systems, the underlying molecular dynamics are poorly understood. Here, we show means to visualize the capture of motile IP3 receptors (IP3Rs) at ERMCs and document the immediate consequences for calcium signaling and metabolism. IP3Rs are of particular interest because their presence provides a scaffold for ERMCs that mediate local calcium signaling, and their function outside of ERMCs depends on their motility. Unexpectedly, in a cell model with little ERMC Ca2+ coupling, IP3Rs …

Functional Determination Of Calcium-Binding Sites Required For The Activation Of Inositol 1,4,5-Trisphosphate Receptors, Vikas Arige, Lara E Terry, Larry E Wagner, Sundeep Malik, Mariah R Baker, Guizhen Fan, Suresh K Joseph, Irina I Serysheva, David I Yule

Journal Articles

Inositol 1,4,5-trisphosphate receptors (IP3Rs) initiate a diverse array of physiological responses by carefully orchestrating intracellular calcium (Ca2+) signals in response to various external cues. Notably, IP3R channel activity is determined by several obligatory factors, including IP3, Ca2+, and ATP. The critical basic amino acid residues in the N-terminal IP3-binding core (IBC) region that facilitate IP3 binding are well characterized. In contrast, the residues conferring regulation by Ca2+ have yet to be ascertained. Using comparative structural analysis of Ca2+-binding sites identified in two main families of intracellular Ca2+-release channels, ryanodine receptors (RyRs) and IP3Rs, we identified putative acidic residues coordinating Ca2+ …

Synthesis Of 3,4,5-Trisubstituted Isoxazoles In Water Via A [3 + 2]-Cycloaddition Of Nitrile Oxides And 1,3-Diketones, Β-Ketoesters, Or Β-Ketoamides, Md Imran Hossain, Md Imdadul H. Khan, Seong Jong Kim, Hoang V. Le

Faculty and Student Publications

Herein we report a method for the synthesis of 3,4,5-trisubstituted isoxazoles in water under mild basic conditions at room temperature via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides. We optimized the reaction conditions to control the selectivity of the production of isoxazoles and circumvent other competing reactions, such as O-imidoylation or hetero [3 + 2]-cycloaddition. The reaction happens fast in water and completes within 1-2 hours, which provides an environmentally friendly access to 3,4,5-trisubstituted isoxazoles, an important class of structures found in numerous bioactive natural products and pharmaceuticals. Additionally, we optimized the reaction conditions to …

Aging Induces Profound Changes In Sncrna In Rat Sperm And These Changes Are Modified By Perinatal Exposure To Environmental Flame Retardant, Alexander Suvorov, J. Richard Pilsner, Vladimir Naumov, Victoria Shtratnikova, Anna Zheludkevich, Evgeny Gerasimov, Maria Logachev, Oleg Sergeyev

Environmental Health Sciences Faculty Publication Series

Advanced paternal age at fertilization is a risk factor for multiple disorders in offspring and may be linked to age-related epigenetic changes in the father’s sperm. An understanding of aging-related epigenetic changes in sperm and environmental factors that modify such changes is needed. Here, we characterize changes in sperm small non-coding RNA (sncRNA) between young pubertal and mature rats. We also analyze the modification of these changes by exposure to environmental xenobiotic 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47). sncRNA libraries prepared from epididymal spermatozoa were sequenced and analyzed using DESeq 2. The distribution of small RNA fractions changed with age, with fractions mapping …

Redox Regulation Of Type-I Inositol Trisphosphate Receptors In Intact Mammalian Cells., Suresh K. Joseph, Michael P. Young, Kamil Alzayady, David I. Yule, Mehboob Ali, David M. Booth, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

A sensitization of inositol 1,4,5-trisphosphate receptor (IP3R)-mediated Ca2+ release is associated with oxidative stress in multiple cell types. These effects are thought to be mediated by alterations in the redox state of critical thiols in the IP3R, but this has not been directly demonstrated in intact cells. Here, we utilized a combination of gel-shift assays with MPEG-maleimides and LC-MS/MS to monitor the redox state of recombinant IP3R1 expressed in HEK293 cells. We found that under basal conditions, ∼5 of the 60 cysteines are oxidized in IP3R1. Cell treatment with 50 μm thimerosal altered gel shifts, indicating oxidation of ∼20 cysteines. …

Mechanisms Of Modulation Of Brain Microvascular Endothelial Cells Function By Thrombin., Eugen Brailoiu, Megan M. Shipsky, Guang Yan, Mary E. Abood, G. Cristina Brailoiu

College of Pharmacy Faculty Papers

Brain microvascular endothelial cells are a critical component of the blood-brain barrier. They form a tight monolayer which is essential for maintaining the brain homeostasis. Blood-derived proteases such as thrombin may enter the brain during pathological conditions like trauma, stroke, and inflammation and further disrupts the permeability of the blood-brain barrier, via incompletely characterized mechanisms. We examined the underlying mechanisms evoked by thrombin in rat brain microvascular endothelial cells (RBMVEC). Our results indicate that thrombin, acting on protease-activated receptor 1 (PAR1) increases cytosolic Ca

The Chronostratigraphy Of The Haua Fteah Cave (Cyrenaica, Northeast Libya) - Optical Dating Of Early Human Occupation During Marine Isotope Stages 4, 5 And 6, Zenobia Jacobs, Bo Li, Lucy Farr, Evan Hill, C Hunt, Sacha C. Jones, Ryan J. Rabett, Tim Reynolds, Richard G. Roberts, David Simpson, Graeme Barker

Faculty of Science, Medicine and Health - Papers: part A

The paper presents the results of optical dating of potassium-rich feldspar grains obtained from the Haua Fteah cave in Cyrenaica, northeast Libya, focussing on the chronology of the Deep Sounding excavated by Charles McBurney in the 1950s and re-excavated recently. Samples were also collected from a 1.25 m-deep trench (Trench S) excavated during the present project below the basal level of the Deep Sounding. Optically stimulated luminescence (OSL) data sets for multi-grain, single aliquots of quartz for samples from the Middle Trench were previously published. Re-analyses of these OSL data confirm significant variation in the dose saturation levels of the …

Cost Effectiveness Of A Multi-Component School-Based Physical Activity Intervention Targeting Adolescents: The 'Physical Activity 4 Everyone' Cluster Randomized Trial, Rachel Sutherland, Penny Reeves, Elizabeth Campbell, David R. Lubans, Philip J. Morgan, Nicole Nathan, Luke Wolfenden, Anthony D. Okely, Karen Gillham, Lynda Davies, John Wiggers

Illawarra Health and Medical Research Institute

Background Few school-based interventions have been successful in reducing physical activity decline and preventing overweight and obesity in adolescent populations. As a result, few cost effectiveness analyses have been reported. The aim of this paper is to report the cost and cost effectiveness of the Physical Activity 4 Everyone (PA4E1) intervention which was a multi-component intervention implemented in secondary schools located in low-income communities. Cost effectiveness was assessed using both the physical activity and weight status trial outcomes.

Methods Intervention and Study Design: The PA4E1 cluster randomised controlled trial was implemented in 10 Australian secondary schools (5 intervention: 5 …

Mechanisms Of Activation Of Nucleus Accumbens Neurons By Cocaine Via Sigma-1 Receptor-Inositol 1,4,5-Trisphosphate-Transient Receptor Potential Canonical Channel Pathways., Jeffrey L. Barr, Elena Deliu, Gabriela Cristina Brailoiu, Pingwei Zhao, Guang Yan, Mary E. Abood, Ellen M. Unterwald, Eugen Brailoiu

College of Pharmacy Faculty Papers

Cocaine promotes addictive behavior primarily by blocking the dopamine transporter, thus increasing dopamine transmission in the nucleus accumbens (nAcc); however, additional mechanisms are continually emerging. Sigma-1 receptors (σ1Rs) are known targets for cocaine, yet the mechanisms underlying σ1R-mediated effects of cocaine are incompletely understood. The present study examined direct effects of cocaine on dissociated nAcc neurons expressing phosphatidylinositol-linked D1 receptors. Endoplasmic reticulum-located σ1Rs and inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) were targeted using intracellular microinjection. IP3 microinjection robustly elevated intracellular Ca(2+) concentration, [Ca(2+)]i. While cocaine alone was devoid of an effect, the IP3-induced response was σ1R-dependently enhanced by cocaine co-injection. Likewise, …

3,4,5-Trichloroaniline Nephrotoxicity In Vitro: Potential Role Of Free Radicals And Renal Biotransformation, Christopher Racine, Dakota Ward, Dianne K. Anestis, Travis Ferguson, Deborah Preston, Gary O. Rankin

Pharmaceutical Science and Research

Chloroanilines are widely used in the manufacture of drugs, pesticides and industrial intermediates. Among the trichloroanilines, 3,4,5-trichloroaniline (TCA) is the most potent nephrotoxicant in vivo. The purpose of this study was to examine the nephrotoxic potential of TCA in vitro and to determine if renal biotransformation and/or free radicals contributed to TCA cytotoxicity using isolated renal cortical cells (IRCC) from male Fischer 344 rats as the animal model. IRCC (~4 million cells/mL; 3 mL) were incubated with TCA (0, 0.1, 0.25, 0.5 or 1.0 mM) for 60–120 min. In some experiments, IRCC were pretreated with an antioxidant or a …

Isoform- And Species-Specific Control Of Inositol 1,4,5-Trisphosphate (Ip3) Receptors By Reactive Oxygen Species., Száva Bánsághi, Tünde Golenár, Muniswamy Madesh, György Csordás, Satish P. Ramachandrarao, Kumar Sharma, David I Yule, Suresh K Joseph, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Reactive oxygen species (ROS) stimulate cytoplasmic [Ca(2+)] ([Ca(2+)]c) signaling, but the exact role of the IP3 receptors (IP3R) in this process remains unclear. IP3Rs serve as a potential target of ROS produced by both ER and mitochondrial enzymes, which might locally expose IP3Rs at the ER-mitochondrial associations. Also, IP3Rs contain multiple reactive thiols, common molecular targets of ROS. Therefore, we have examined the effect of superoxide anion (O2) on IP3R-mediated Ca(2+) signaling. In human HepG2, rat RBL-2H3, and chicken DT40 cells, we observed [Ca(2+)]c spikes and frequency-modulated oscillations evoked by a O2 donor, xanthine (X) + xanthine oxidase (XO), dose-dependently. …

Sequential 1,4- And 1,2-Addition Reactions To Α,Β-Unsaturated N-Acyliminium Ions: A New Strategy For The Synthesis Of Spiro And Bridged Heterocycles, Arife Yazici, Stephen G. Pyne

Faculty of Science, Medicine and Health - Papers: part A

Novel bicyclic and tetracyclic spirocycles and tricyclic bridged heterocyclic systems can be readily prepared from sequential 1,4- and 1,2-addition reactions of latent bis-nucleophiles to α,β-unsaturated N-acyliminium ions.

Meeting Recommended Dietary Intakes In Meal Plans With ≥4 Servings Of Grain-Based Foods Daily, Yasmine Probst, Linda Tapsell

Faculty of Science, Medicine and Health - Papers: part A

Objective To develop meal plans using grain-based foods demonstrating how to incorporate wholegrain foods into a balanced diet for weight maintenance for different cuisines. The present study examines the ability of meal plans with ≥4 grain-based servings daily to meet nutrient recommendations using lacto-ovo vegetarian and rice-based cuisines. Design Eighteen plans from each cuisine for three age brackets for both genders were developed. Plans aimed for ≥4 servings of grain-based foods daily, with separate plans for all wholegrain, all refined-grain and half wholegrain–half refined-grain foods. Meal plans followed an isoenergetic approach and were designed to meet specific Australian nutrient reference …

A Weak El Niño/Southern Oscillation With Delayed Seasonal Growth Around 4,300 Years Ago, H V. Mcgregor, M J. Fischer, M K. Gagan, David Fink, S J. Phipps, H Wong, C D. Woodroffe

Faculty of Science, Medicine and Health - Papers: part A

Earth’s interannual climate variability is dominated by El Niño/Southern Oscillation (ENSO). Palaeoclimate records indicate a lower ENSO variance during the middle Holocene compared with today1, 2, 3, 4, 5, 6; however, model simulations have not reproduced the full magnitude of the changes7, 8, 9, 10, and whether external forcing drives large intrinsic ENSO variability11 is therefore a matter of considerable debate. Here we present a 175-year-long, monthly resolved oxygen isotope record, obtained from a Porites coral microatoll located on Kiritimati (Christmas) Island, in the NINO3.4 region of the central equatorial Pacific. Our quantitative record of ENSO variability about 4,300 years …

Scd1 Plays A Tumor-Suppressive Role In Survival Of Leukemia Stem Cells And The Development Of Chronic Myeloid Leukemia, H Zhang, H Li, N Ho, Dongguang Li, Shaoguang Li

Research outputs 2012

Chronic myeloid leukemia (CML) is derived from a stem cell, and it is widely accepted that the existence of leukemia stem cells (LSCs) is one of the major reasons for the relapse of CML treated with kinase inhibitors. Key to eradicating LSCs is to identify genes that play a critical role in survival regulation of these stem cells. Using BCR-ABL-induced CML mouse model, here we show that expression of the stearoyl-CoA desaturase 1 (Scd1) gene is downregulated in LSCs and that Scd1 plays a tumor-suppressive role in LSCs with no effect on the function of normal hematopoietic stem cells. Deletion …

Electrodeposition Of Pyrrole And 3-(4-Tert-Butylphenyl)Thiophene Copolymer For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Pawel Wagner, Yang Yang, Xin Ding, David L. Officer, Gordon G. Wallace

Faculty of Science, Medicine and Health - Papers: part A

The electropolymerization of pyrrole (Py), 3-(4-tert-butylphenyl)thiophene (TPT) monomer or the mixed Py and TPT monomers on stainless steel mesh substrate were performed in 1 M LiClO4/acetonitrile solution. A much lower potential of 0.75 V was required for the co-electropolymerization of Py and TPT, in sharp contrast to that of 1.20 V for poly(3-(4-tert-butylphenyl)thiophene) (PTPT) formation. The resultant homopolymers and copolymer were characterized with FESEM and FTIR, and assembled into supercapacitors to investigate their electrochemical performances. The copolymer electrode delivered the highest specific capacitance of 291 F g−1 at a scan rate of 5 mV s−1, in comparison with that of …

Comments On Slee Et Al. (2012). A Reassessment Of Last Interglacial Deposits At Mary Ann Bay, Tasmania. Quaternary Australasia 29: 4-11, Colin V. Murray-Wallace, Eric A. Colhoun, Albert Goede, Patrick G. Quilty

Faculty of Science, Medicine and Health - Papers: part A

It is always pleasing to see additional work undertaken on sedimentary successions that are critical to the understanding of Quaternary environmental changes. The deposits at Mary Ann Bay, as with other last interglacial (MIS 5e; 128-118 ka) coastal-marine successions in Tasmania, are critical for demonstrating that the region has experienced a different relative sea-level history to mainland southeastern Australia, and that parts of Tasmania have been uplifted by 16-17 m since the last interglacial maximum. Unfortunately, the recently published paper by Slee et al. (2012) gives credence to two thermoluminescence (TL) ages which must be inaccurate. In uncritically accepting the …

Chapter 4: 'Water' - Resource Efficiency In Asia And The Pacific, Kim Alexander, James West

Illawarra Health and Medical Research Institute

Water is essential to life, supplying human needs and maintaining ecosystems for all living species. Water resources are important to socio-economic development, providing material input into production and consumption activities and acting as sinks for waste material. Consequently, water resource systems are closely linked to the economic use of resources. This section of the report investigates water resource and water use patterns, trends in water use, and resultant stress on water systems across the Asia-Pacific region.

Long Lasting Synchronization Of Calcium Oscillations By Cholinergic Stimulation In Isolated Pancreatic Islets, Min Zhang, Bernard Fendler, Bradford Peercy, Pranay Goel, Richard Bertram, Arthur Sherman, Leslie Satin

Pharmacology and Toxicology Publications

Abstract

Individual mouse pancreatic islets exhibit oscillations in [Ca²⁺]_i and insulin secretion in response to glucose in vitro, but how the oscillations of a million islets are coordinated within the human pancreas in vivo is unclear. Islet to islet synchronization is necessary, however, for the pancreas to produce regular pulses of insulin. To determine whether neurohormone release within the pancreas might play a role in coordinating islet activity, [Ca²⁺]_i changes in 4–6 isolated mouse islets were simultaneously monitored before and after a transient pulse of a putative synchronizing agent. The degree of synchronicity was …

Effects, Uptake, And Fate Of 2,4,6-Trinitrotoluene Aged In Soil In Plants And Worms, Elly Ph Best, Henry E. Tatem, Kaaren N. Geter, Melissa L. Wells, Brian K. Lane

US Army Corps of Engineers

The present study was aimed at providing data to be used at predicting exposure-based effects of 2,4,6-trinitrotoluene (TNT) aged in soil on endpoint organisms representing two trophic levels. These data can be used to define criteria or reference values for environmental management and conducting specific risk assessment. Long-term exposure tests were conducted to evaluate sublethal toxicity and uptake of aged soil-based explosives, with TNT as the main contaminant. In these tests, plants were exposed for 55 d, and biomass and explosives residues were determined. Worms were exposed for 28 and 42 d, and biomass, number, and tissue residues were determined. …

Elucidating A Normal Function Of Huntingtin By Functional And Microarray Analysis Of Huntingtin-Null Mouse Embryonic Fibroblasts., Hua Zhang, Sudipto Das, Quan-Zhen Li, Ioannis Dragatsis, Joyce Repa, Scott Zeitlin, György Hajnóczky, Ilya Bezprozvanny

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The polyglutamine expansion in huntingtin (Htt) protein is a cause of Huntington's disease (HD). Htt is an essential gene as deletion of the mouse Htt gene homolog (Hdh) is embryonic lethal in mice. Therefore, in addition to elucidating the mechanisms responsible for polyQ-mediated pathology, it is also important to understand the normal function of Htt protein for both basic biology and for HD. RESULTS: To systematically search for a mouse Htt function, we took advantage of the Hdh +/- and Hdh-floxed mice and generated four mouse embryonic fibroblast (MEF) cells lines which contain a single copy of the Hdh …

Selective Role For Superoxide In Insp3 Receptor-Mediated Mitochondrial Dysfunction And Endothelial Apoptosis., Muniswamy Madesh, Brian J Hawkins, Tatyana Milovanova, Cunnigaiper D Bhanumathy, Suresh K Joseph, Satish P Ramachandrarao, Kumar Sharma, Tomohiro Kurosaki, Aron B Fisher

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Reactive oxygen species (ROS) play a divergent role in both cell survival and cell death during ischemia/reperfusion (I/R) injury and associated inflammation. In this study, ROS generation by activated macrophages evoked an intracellular Ca2+ ([Ca2+]i) transient in endothelial cells that was ablated by a combination of superoxide dismutase and an anion channel blocker. [Ca2+]i store depletion, but not extracellular Ca2+ chelation, prevented [Ca2+]i elevation in response to O2*- that was inositol 1,4,5-trisphosphate (InsP3) dependent, and cells lacking the three InsP3 receptor (InsP3R) isoforms failed to display the [Ca2+]i transient. Importantly, the O2*--triggered Ca2+ mobilization preceded a loss in mitochondrial membrane …

Single-Channel Properties In Endoplasmic Reticulum Membrane Of Recombinant Type 3 Inositol Trisphosphate Receptor., D O Mak, S Mcbride, V Raghuram, Y Yue, Suresh K. Joseph, J K Foskett

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The inositol 1,4,5-trisphosphate receptor (InsP(3)R) is an intracellular Ca(2+)-release channel localized in endoplasmic reticulum (ER) with a central role in complex Ca(2+) signaling in most cell types. A family of InsP(3)Rs encoded by several genes has been identified with different primary sequences, subcellular locations, variable ratios of expression, and heteromultimer formation. This diversity suggests that cells require distinct InsP(3)Rs, but the functional correlates of this diversity are largely unknown. Lacking are single-channel recordings of the recombinant type 3 receptor (InsP(3)R-3), a widely expressed isoform also implicated in plasma membrane Ca(2+) influx and apoptosis. Here, we describe functional expression and single-channel …