DOCSLIB.ORG

Arginase Inhibition Attenuates Arteriogenesis and Interferes With

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Arginase Inhibition Attenuates Arteriogenesis and Interferes With Laboratory Investigation (2016) 96, 830–838 © 2016 USCAP, Inc All rights reserved 0023-6837/16 Arginase inhibition attenuates arteriogenesis and interferes with M2 macrophage accumulation Manuel Lasch1,4, Amelia Caballero-Martinez1,4, Kerstin Troidl2,3, Irmengard Schloegl1, Thomas Lautz1 and Elisabeth Deindl1 L-Arginine is the common substrate for nitric oxide synthases (NOS) and arginase. Whereas the contribution of NOS to collateral artery growth (arteriogenesis) has been demonstrated, the functional role of arginase remains to be elucidated and was topic of the present study. Arteriogenesis was induced in mice by ligation of the femoral artery. Laser Doppler perfusion measurements demonstrated a significant reduction in arteriogenesis in mice treated with the arginase inhibitor nor-NOHA (Nω-hydroxy-nor-arginine). Accompanying in vitro results on murine primary arterial endothelial cells and smooth muscle cells revealed that nor-NOHA treatment interfered with cell proliferation and resulted in increased nitrate/ nitrite levels, indicative for increased NO production. Immuno-histological analyses on tissue samples demonstrated that nor-NOHA administration caused a significant reduction in M2 macrophage accumulation around growing collateral arteries. Gene expression studies on isolated growing collaterals evidenced that nor-NOHA treatment abolished the differential expression of Icam1 (intercellular adhesion molecule 1). From our data we conclude that arginase activity is essential for arteriogenesis by promoting perivascular M2 macrophage accumulation as well as arterial cell proliferation. Laboratory Investigation (2016) 96, 830–838; doi:10.1038/labinvest.2016.62; published online 30 May 2016 Cardiovascular diseases such as myocardial infarction or macrophages have been described to contribute to vascular stroke are still the major cause of morbidity and death remodeling.7 worldwide. Current options to treat affected patients are Interestingly, it has been shown that exogenously admini- percutaneous transluminal angioplasty, percutaneous trans- strated nitric oxide (NO) donors promote arteriogenesis.8,9 luminal coronary angioplasty or bypass surgery.1 Aiming to This is somehow amazing as it is well known that NO develop non-invasive therapeutic options to treat such counteracts leukocyte adhesion as well as smooth muscle cell 10 patients much effort is made to understand the molecular proliferation (for an overview see ), two essential processes mechanisms of arteriogenesis. Arteriogenesis is the growth of in arteriogenesis. Indeed, the mechanistic function of NO for a natural bypass and occurs as adaptive response of the body collateral artery growth still remains elusive. In the body, NO can be produced by three different to vascular occlusion.1 It is well established that the trigger for isoforms of the NOS enzyme: NOS1, NOS2, and NOS3 arteriogenesis is increased laminar shear stress.2 This (neuronal, inducible, and endothelial NO synthase). These increased mechanical load is exerted on ECs (endothelial isoforms display differences in tissue distribution, intracel- cells) of pre-existing arteriolar connections by the redirected 11 3 lular location, molecular regulation, and enzymatic kinetics. blood flow caused by occlusion of a conductance artery. All three isoforms have been shown to be involved in Animal models, mainly for peripheral arteriogenesis, arteriogenesis.9,12–14 NOS1 is mainly localized in smooth evidenced that increased shear stress results in activation of muscle cells (SMCs) of collateral arteries and is upregulated the arteriolar endothelium with subsequent upregulation of during arteriogenesis.12 NOS3 presents the major form of monocyte chemoattractant protein-1 (MCP-1) as well as NOS in ECs, and has a role in maintaining native ICAM1 presenting the prerequisite for monocyte recruitment, collateral density.14 NOS3 enzymatic activity is critical for – adhesion, and extravasation.4 6 After extravasation, mono- NO-mediated vasodilation in collateral vessels, however, is cytes mature to macrophages, whereby M1 as well as M2 not essential for effective collateral artery growth as evidenced 1Walter-Brendel-Centre of Experimental Medicine, LMU Munich, Munich, Germany; 2Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany and 3Department of Vascular and Endovascular Surgery, University Hospital Frankfurt, Frankfurt, Germany Correspondence: Dr E Deindl, PhD, Walter-Brendel-Centre of Experimental Medicine, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany. E-mail: [email protected] 4These authors contributed equally to this work. Received 9 November 2015; revised 5 April 2016; accepted 21 April 2016 830 Laboratory Investigation | Volume 96 August 2016 | www.laboratoryinvestigation.org Arginase inhibition in arteriogenesis M Lasch et al by histological analyses.9,13 NOS2 deficiency in contrast surgical procedure and administered until the end of the strongly interferes with collateral artery growth.9 As NOS2 experiment. is the major form of NOS expressed in leukocytes it is likely that leukocyte derived NO is relevant for effective Femoral Artery Ligation, Laser Doppler Perfusion and arteriogenesis. Blood Pressure Measurements L-Arginine is the substrate for NOS, however, also presents To induce peripheral arteriogenesis, C57/BL6 mice under- the substrate for arginase.11 It has previously been demon- went unilateral femoral artery ligation (occ) of the right leg strated that arteriogenesis is reduced in animals treated whereas the left leg was sham operated as previously 5,20 with L-NAME, which was attributed to disrupted NO described. During surgery none of the mice died and no 15 production. However, L-NAME does not only inhibit NOS necrosis or infection of the wound was observed during the but also arginase.16 There are two different isoforms of observation period. arginase, arginase 1 and arginase 2, showing different Blood flow measurements were conducted using the LDI subcellular locations. Whereas arginase 1 is located in the technique (Moor LDI 5061 and Moor Software Version 3.01, cytosol, arginase 2 is a mitochondrial enzyme.11 The function from Moor Instruments, Remagen, Germany) as previously 5,20 of arginase 2 is less well characterized, however, arginase 1 has described. Mice were anesthetized and kept at 37 °C body been shown to be essential for vascular cell proliferation, and temperature in a heating chamber for 10 min. The measure- to be a feature of M2 macrophages.11 We therefore asked ments were performed before surgery, directly after surgery, whether arginase is essential for the process of arteriogenesis. and on day 3 and day 7 after surgery. The right-to-left ratio For our study, we employed a murine hindlimb model in was calculated for each mouse and background tissue values which femoral artery ligation results in collateral artery were subtracted to eliminate tissue bias. growth.5 We evaluated the efficiency of the process of Blood pressure was measured non-invasively by determin- arteriogenesis by measuring hindlimb perfusion non- ing the tail blood pressure using a two-module system invasively by means of laser Doppler imaging (LDI) and consisting of an occlusion tail cuff and a volume pressure quantified macrophage infiltration as well as Icam1 expression recording sensor from CODA System (Kent Scientific, in mice treated with the arginase inhibitor nor-NOHA Torrington, CT, USA). The measurements were done as 21 compared with saline-treated control mice. Furthermore, we previously described. The blood pressure was measured one performed accessory in vitro proliferation assays on primary day after the surgical procedure and at day 7. murine arterial ECs and SMCs and investigated NO production by means of nitrate/nitrite measurements. Tissue Sampling for Immuno-Histology and RNA Expression Analyses For RNA tissue sampling, the abdominal aorta was cannu- MATERIALS AND METHODS lated, and both hindlimbs were perfused with latex flexible Reagents compound (Chicago Latex, Chicago, IL, USA) to visualize L-Lys (L-lysine monohydrochloride) and L-Arg (L-arginine) superficial collateral arteries. Twelve hours after surgery, two were purchased from Sigma-Aldrich (St. Louis, MO, USA), superficial collateral arteries per animal per side were isolated. nor-NOHA from Bachem (Bubendorf, Switzerland). For All samples were snap frozen in dry ice and stored at –80 °C. proliferation assays, L-Arg-, L-Lys- phenol-free DMEM ’ ’ For histology tissue sampling on day 7 after the surgical (Dulbecco s Modified Eagle s Medium; Sigma-Aldrich) was procedure, mice were perfused as described above with 0.1% μ supplemented with 272 M L-Lys. (w/v) adenosine (Sigma-Aldrich) and 0.5% (w/v) bovine serum albumin (Sigma-Aldrich) dissolved in phosphate- Animals and Treatments buffered saline (PBS; PAN Biotech, Aidenbach, Germany), The investigation was approved and controlled by the local pH7.4, followed by 3% (for cryopreservation) or 4% (for ethics committee and carried out according to the guidelines paraffin embedding) paraformaldehyde in PBS, pH7.4, for of the German law for protection of animal life. Mice were 20 min. For cryoconservation adductor muscles were cut and kept under a 12 h day and night cycle with chow and water placed in 15% (w/v) sucrose in PBS for 4 h and in 30% provided ad libitum. Eight to 10 weeks old C57/BL6 male sucrose (w/v) overnight at 4 °C. Muscle samples were then mice (Charles River, Sulzfeld, Germany) were used for in vivo embedded in tissue tek
Load more

Recommended publications
  • Birthdating of Myenteric Neuron Subtypes in the Small Intestine of the Mouse
    RESEARCH ARTICLE Birthdating of Myenteric Neuron Subtypes in the Small Intestine of the Mouse Annette J. Bergner,1 Lincon A. Stamp,1 David G. Gonsalvez,1 Margaret B. Allison,2,3 David P. Olson,4 Martin G. Myers Jr,2,3,5 Colin R. Anderson,1 and Heather M. Young1* 1Department of Anatomy & Neuroscience, University of Melbourne, Victoria, Australia 2Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA 3Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA 4Division of Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA 5Department of Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, USA ABSTRACT vast majority of myenteric neurons had exited the cell There are many different types of enteric neurons. Pre- cycle by P10. We did not observe any EdU1/NOS11 vious studies have identified the time at which some myenteric neurons in the small intestine of adult mice enteric neuron subtypes are born (exit the cell cycle) in following EdU injection at E10.5 or E11.5, which was the mouse, but the birthdates of some major enteric unexpected, as previous studies have shown that NOS1 neuron subtypes are still incompletely characterized or neurons are present in E11.5 mice. Studies using the unknown. We combined 5-ethynynl-20-deoxyuridine proliferation marker Ki67 revealed that very few NOS1 (EdU) labeling with antibody markers that identify myen- neurons in the E11.5 and E12.5 gut were proliferating. teric neuron subtypes to determine when neuron sub- However, Cre-lox-based genetic fate-mapping revealed types are born in the mouse small intestine.
    [Show full text]
  • The Baseline Structure of the Enteric Nervous System and Its Role in Parkinson’S Disease
    life Review The Baseline Structure of the Enteric Nervous System and Its Role in Parkinson’s Disease Gianfranco Natale 1,2,* , Larisa Ryskalin 1 , Gabriele Morucci 1 , Gloria Lazzeri 1, Alessandro Frati 3,4 and Francesco Fornai 1,4 1 Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy; [email protected] (L.R.); [email protected] (G.M.); [email protected] (G.L.); [email protected] (F.F.) 2 Museum of Human Anatomy “Filippo Civinini”, University of Pisa, 56126 Pisa, Italy 3 Neurosurgery Division, Human Neurosciences Department, Sapienza University of Rome, 00135 Rome, Italy; [email protected] 4 Istituto di Ricovero e Cura a Carattere Scientifico (I.R.C.C.S.) Neuromed, 86077 Pozzilli, Italy * Correspondence: [email protected] Abstract: The gastrointestinal (GI) tract is provided with a peculiar nervous network, known as the enteric nervous system (ENS), which is dedicated to the fine control of digestive functions. This forms a complex network, which includes several types of neurons, as well as glial cells. Despite extensive studies, a comprehensive classification of these neurons is still lacking. The complexity of ENS is magnified by a multiple control of the central nervous system, and bidirectional communication between various central nervous areas and the gut occurs. This lends substance to the complexity of the microbiota–gut–brain axis, which represents the network governing homeostasis through nervous, endocrine, immune, and metabolic pathways. The present manuscript is dedicated to Citation: Natale, G.; Ryskalin, L.; identifying various neuronal cytotypes belonging to ENS in baseline conditions.
    [Show full text]
  • Nitric Oxide Enhances the Sensitivity of Alpaca Melanocytes to Respond to A-Melanocyte-Stimulating Hormone by Up-Regulating Melanocortin-1 Receptor
    Biochemical and Biophysical Research Communications 396 (2010) 849–853 Contents lists available at ScienceDirect Biochemical and Biophysical Research Communications journal homepage: www.elsevier.com/locate/ybbrc Nitric oxide enhances the sensitivity of alpaca melanocytes to respond to a-melanocyte-stimulating hormone by up-regulating melanocortin-1 receptor Yanjun Dong, Jing Cao, Haidong Wang, Jie Zhang, Zhiwei Zhu, Rui Bai, HuanQing Hao, Xiaoyan He, Ruiwen Fan, Changsheng Dong * College of Animal Science and Technology, Shanxi Agricultural University, 030801 Taigu, Shanxi, China article info abstract Article history: Nitric oxide (NO) and a-melanocyte-stimulating hormone (a-MSH) have been correlated with the syn- Received 25 April 2010 thesis of melanin. The NO-dependent signaling of cellular response to activate the hypothalamopituitary Available online 6 May 2010 proopiomelanocortin system, thereby enhances the hypophysial secretion of a-MSH to stimulate a-MSH- receptor responsive cells. In this study we investigated whether an NO-induced pathway can enhance the Keywords: ability of the melanocyte to respond to a-MSH on melanogenesis in alpaca skin melanocytes in vitro.Itis Nitric oxide (NO) important for us to know how to enhance the coat color of alpaca. We set up three groups for experiments a-Melanocyte-stimulating hormone using the third passage number of alpaca melanocytes: the control cultures were allowed a total of 5 days (a-MSH) growth; the UV group cultures like the control group but the melanocytes were then irradiated everyday Melanocortin-1 receptor (MC1R) 2 Alpaca (once) with 312 mJ/cm of UVB; the UV + L-NAME group is the same as group UV but has the addition of Melanocyte 300 lM L-NAME (every 6 h).
    [Show full text]
  • Synthase from Rat Liver
    Proc. Nati. Acad. Sci. USA Vol. 89, pp. 5361-5365, June 1992 Biochemistry Purification of a distinctive form of endotoxin-induced nitric oxide synthase from rat liver (endothelium-derived relaxing factor/L-arginine/calmodulin) TOM EVANS, ADAM CARPENTER, AND JONATHAN COHEN* Department of Infectious Diseases, Royal Postgraduate Medical School, Du Cane Road, London W12 ONN, United Kingdom Communicated by Robert F. Furchgott, March 6, 1992 (received for review November 18, 1991) ABSTRACT An endotoxin-induced form of nitric oxide We are interested in the hepatic form of the NO synthase, synthase (EC 1.14.23) was purified to homogeneity from rat which is induced by the administration of endotoxin (8). liver by sequential anion-exchange chromatography and afflin- Livers from untreated animals show minimal NO synthase ity chromatography using 2',5'-ADP-Sepharose. The enzyme activity. NO production in the liver seems to suppress protein has a subunit molecular mass of 135 kDa as determined by synthesis and protects the liver against damage (18). We have SDS/PAGE, a maximum specific activity of 462 nmol of purified this enzyme to homogeneity and show that it is citrulline formed from arginine per min per mg, and a K. for strongly stimulated by calmodulin, whereas its activity is arginine of 11 jIM. The enzyme was strongly stimulated by the only affected to a small degree by free calcium concentra- addition of calmodulin with an EC50 of 2 nM, but removal of tions-even in the presence ofcalmodulin. Thus, this hepatic free calcium from the assay medium only reduced activity by endotoxin-induced NO synthase is distinct from that de- 15%.
    [Show full text]
  • Effect of Arginase Inhibition on Ischemia-Reperfusion Injury in Patients with Coronary Artery Disease with and Without Diabetes Mellitus
    Effect of Arginase Inhibition on Ischemia-Reperfusion Injury in Patients with Coronary Artery Disease with and without Diabetes Mellitus Oskar Ko¨ vamees*, Alexey Shemyakin, John Pernow Department of Medicine, Karolinska Institutet, Stockholm, Sweden Abstract Background: Arginase competes with nitric oxide synthase for their common substrate L-arginine. Up-regulation of arginase in coronary artery disease (CAD) and diabetes mellitus may reduce nitric oxide bioavailability contributing to endothelial dysfunction and ischemia-reperfusion injury. Arginase inhibition reduces infarct size in animal models. Therefore the aim of the current study was to investigate if arginase inhibition protects from endothelial dysfunction induced by ischemia-reperfusion in patients with CAD with or without type 2 diabetes (Clinical trial registration number: NCT02009527). Methods: Male patients with CAD (n = 12) or CAD + type 2 diabetes (n = 12), were included in this cross-over study with blinded evaluation. Endothelium-dependent vasodilatation was assessed by flow-mediated dilatation (FMD) of the radial artery before and after 20 min ischemia-reperfusion during intra-arterial infusion of the arginase inhibitor (Nv-hydroxy-nor- L-arginine, 0.1 mg/min) or saline. Results: The forearm ischemia-reperfusion was well tolerated. Endothelium-independent vasodilatation was assessed by sublingual nitroglycerin. Ischemia-reperfusion decreased FMD in patients with CAD from 12.765.2% to 7.964.0% during saline administration (P,0.05). Nv-hydroxy-nor-L-arginine administration prevented the decrease in FMD in the CAD group (10.364.3% at baseline vs. 11.563.6% at reperfusion). Ischemia-reperfusion did not significantly reduce FMD in patients with CAD + type 2 diabetes. However, FMD at reperfusion was higher following nor-NOHA than following saline administration in both groups (P,0.01).
    [Show full text]
  • Influence of Functional Variant of Neuronal Nitric Oxide Synthase on Impulsive Behaviors in Humans
    ORIGINAL ARTICLE Influence of Functional Variant of Neuronal Nitric Oxide Synthase on Impulsive Behaviors in Humans Andreas Reif, MD; Christian P. Jacob, MD; Dan Rujescu, MD; Sabine Herterich, PhD; Sebastian Lang, MD; Lise Gutknecht, PhD; Christina G. Baehne, Dipl-Psych; Alexander Strobel, PhD; Christine M. Freitag, MD; Ina Giegling, MD; Marcel Romanos, MD; Annette Hartmann, MD; Michael Rösler, MD; Tobias J. Renner, MD; Andreas J. Fallgatter, MD; Wolfgang Retz, MD; Ann-Christine Ehlis, PhD; Klaus-Peter Lesch, MD Context: Human personality is characterized by sub- Main Outcome Measures: For the association stud- stantial heritability but few functional gene variants have ies, the major outcome criteria were phenotypes rel- been identified. Although rodent data suggest that the evant to impulsivity, namely, the dimensional pheno- neuronal isoform of nitric oxide synthase (NOS-I) modi- type conscientiousness and the categorical phenotypes fies diverse behaviors including aggression, this has not adult ADHD, aggression, and cluster B personality been translated to human studies. disorder. Objectives: To investigate the functionality of an NOS1 Results: A novel functional promoter polymorphism in promoter repeat length variation (NOS1 Ex1f variable NOS1 was associated with traits related to impulsivity, number tandem repeat [VNTR]) and to test whether it including hyperactive and aggressive behaviors. Specifi- is associated with phenotypes relevant to impulsivity. cally, the short repeat variant was more frequent in adult ADHD, cluster B personality disorder, and autoaggres- Design: Molecular biological studies assessed the cel- sive and heteroaggressive behavior. This short variant lular consequences of NOS1 Ex1f VNTR; association came along with decreased transcriptional activity of the studies were conducted to investigate the impact of this genetic variant on impulsivity; imaging genetics was ap- NOS1 exon 1f promoter and alterations in the neuronal plied to determine whether the polymorphism is func- transcriptome including RGS4 and GRIN1.
    [Show full text]
  • The Genetics of Bipolar Disorder
    Molecular Psychiatry (2008) 13, 742–771 & 2008 Nature Publishing Group All rights reserved 1359-4184/08 $30.00 www.nature.com/mp FEATURE REVIEW The genetics of bipolar disorder: genome ‘hot regions,’ genes, new potential candidates and future directions A Serretti and L Mandelli Institute of Psychiatry, University of Bologna, Bologna, Italy Bipolar disorder (BP) is a complex disorder caused by a number of liability genes interacting with the environment. In recent years, a large number of linkage and association studies have been conducted producing an extremely large number of findings often not replicated or partially replicated. Further, results from linkage and association studies are not always easily comparable. Unfortunately, at present a comprehensive coverage of available evidence is still lacking. In the present paper, we summarized results obtained from both linkage and association studies in BP. Further, we indicated new potential interesting genes, located in genome ‘hot regions’ for BP and being expressed in the brain. We reviewed published studies on the subject till December 2007. We precisely localized regions where positive linkage has been found, by the NCBI Map viewer (http://www.ncbi.nlm.nih.gov/mapview/); further, we identified genes located in interesting areas and expressed in the brain, by the Entrez gene, Unigene databases (http://www.ncbi.nlm.nih.gov/entrez/) and Human Protein Reference Database (http://www.hprd.org); these genes could be of interest in future investigations. The review of association studies gave interesting results, as a number of genes seem to be definitively involved in BP, such as SLC6A4, TPH2, DRD4, SLC6A3, DAOA, DTNBP1, NRG1, DISC1 and BDNF.
    [Show full text]
  • Effects of Γ-Aminobutyric Acid on the Erectogenic Properties of Sildenafil
    Available online on www.ijtpr.com International Journal of Toxicological and Pharmacological Research 2017; 9(3); 234-243 ISSN: 0975-5160 Research Article Effects of γ-Aminobutyric Acid on the Erectogenic Properties of Sildenafil Adefegha S A1*, Oyeleye S I1,2 Oboh G1 1Functional food and Nutraceutical Laboratory, Department of Biochemistry, Federal University of Technology, Akure, P.M.B. 704, Akure 340001, Nigeria 2Department of Biomedical Technology, Federal University of Technology, Akure, P.M.B. 704, Akure 340001, Nigeria Available Online:25th July, 2017 ABSTRACT Erectile dysfunction (ED) is a disorder of increasing socio-economic burden. Therapeutic drugs such as sildenafil have been in use for the treatment of ED, but with their associated side effects. γ-aminobutyric acid (GABA) is a neurotransmitter with possible vasodilatory properties. In this study, the effect of GABA on the erectogenic properties of sildenafil was investigated. Aqueous solution of GABA and sildenafil (1 mM) was separately prepared as well as the mixtures of both (75% GABA + 25% sildenafil; 50% GABA + 50% sildenafil; 25% GABA + 75% sildenafil). Thereafter, the in vitro effects of all the studied samples on the activities of arginase, angiotensin-I converting enzyme (ACE) and acetylcholinesterase (AChE) were investigated. The results revealed that all the samples inhibited arginase, ACE and AChE activities. Considering the various combinations, 25% GABA + 75% sildenafil had the highest arginase inhibitory effect, 50% GABA + 50% sildenafil showed the highest ACE inhibiting effect, while 25% GABA + 75% sildenafil exhibited the highest AChE inhibitory effect. Therefore, the observed enzyme inhibiting effect of sildenafil, GABA and their various combinations on rat penile arginase, ACE and AChE activities could be part of the mechanism by which they elicit their erectogenic properties.
    [Show full text]
  • Competitive Metabolism of L-Arginine: Arginase As a Therapeutic Target In
    JBR Journal of Biomedical Research，2011，25(5):299-308 http://elsevier.com/wps/ Review find/journaldescription.cws_ home/723905/description#description Competitive metabolism of L-arginine: arginase as a therapeutic ☆ target in asthma * Jennifer M. Bratt, Amir A. Zeki, Jerold A. Last, Nicholas J. Kenyon Department of Internal Medicine, Division of Pulmonary and Critical Care and Sleep Medicine, University of California, Davis, CA 95616, USA Received 25 April 2011, Revised 24 June 2011, Accepted 21 July 2011 Abstract Exhaled breath nitric oxide (NO) is an accepted asthma biomarker. Lung concentrations of NO and its amino acid precursor, L-arginine, are regulated by the relative expressions of the NO synthase (NOS) and arginase iso- forms. Increased expression of arginase I and NOS2 occurs in murine models of allergic asthma and in biopsies of asthmatic airways. Although clinical trials involving the inhibition of NO-producing enzymes have shown mixed results, small molecule arginase inhibitors have shown potential as a therapeutic intervention in animal and cell culture models. Their transition to clinical trials is hampered by concerns regarding their safety and potential tox- icity. In this review, we discuss the paradigm of arginase and NOS competition for their substrate L-arginine in the asthmatic airway. We address the functional role of L-arginine in inflammation and the potential role of arginase inhibitors as therapeutics. Keywords: nitric oxide, L-arginine, arginase, nor-NOHA, nitrosation, nitric oxide synthase INTRODUCTION from accumulation of collagens in the submucosal and [3] Asthma is a common disease characterized by a reticular basement membrane . The airway remod- syndrome of persistent airway inflammation and re- eling and resultant reduction in overall lung function versible airway obstruction.
    [Show full text]
  • Increased Arginine Amino Aciduria/Urea Cycle Disorder
    Newborn Screening ACT Sheet Increased Arginine Amino Aciduria/Urea Cycle Disorder Differential Diagnosis: Argininemia (ARG) Condition Description: The urea cycle is the enzyme cycle whereby ammonia is converted to urea. In argininemia, defects in arginase, a urea cycle enzyme, may result in hyperammonemia. Take the Following IMMEDIATE Actions • Contact family to inform them of the newborn screening result and ascertain clinical status (poor feeding, vomiting, lethargy, tachypnea). • Immediate telephone consultation with pediatric metabolic specialist. (See attached list.) • Evaluate the newborn (poor feeding, vomiting, lethargy, hypotonia, tachypnea, seizures and signs of liver disease). • If any sign is present or infant is ill, IMMEDIATELY initiate emergency treatment for hyperammonemia in consultation with metabolic specialist. • Transport to hospital for further treatment in consultation with metabolic specialist. • Initiate timely confirmatory/diagnostic testing and management, as recommended by specialist. • Initial testing: immediate plasma ammonia, plasma quantitative amino acids, and urine orotic acid. • Repeat newborn screen if second screen has not been done. • Provide family with basic information about hyperammonemia. • Report findings to newborn screening program. Diagnostic Evaluation: Specific diagnosis is made by plasma quantitative amino acid analysis revealing increased arginine and urine orotic acid analysis revealing increased orotic acid, respectively. Blood ammonia determination may also reveal hyperammonemia. Clinical
    [Show full text]
  • Arginase Deficiency
    Arginase Deficiency Lauren Ballard, Alex Belardo, Lainie Boyle, Abby Dryden, Rachel Kirchner, M’Lynn Gwinner, Shreya Nalluri, & Julia Slogar Service Learning Initiative in Biochemistry 5614 (Autumn 2018) Argininemia: An autosomal recessive disorder Video on Inheritance Patterns HNEkidshealth. “Autosomal Recessive Inheritance - Genetics.” YouTube, YouTube, 30 Mar. 2015, www.youtube.com/watch?v=Nv6qUsKYodA. Argininemia ● Inherited disorder that causes arginine (amino acid) and ammonia to build up in the blood ● The deficiency usually becomes evident by 3 years of age ● Occurs once in every 300,000 to 1,000,000 individuals ● Caused by a mutation in the ARG1 gene, which encodes the enzyme arginase Baby's first foods: Where to begin? Digital image retrieved ● Inherited in an autosomal recessive pattern October 31, 2018 from https://www.kabritausa.com/blog/babys-first-foods-begin/ Protein Metabolism Amino acids Peptide Protein How Your Body Uses Amino Acids as Proteins. Digital image retrieved October 31, 2018 https://socratic.org/questions/amino-acids-as-monomers-of-protein ● Amino Acids are the building blocks of proteins ● Dietary protein must be broken down into amino acids Protein Metabolism + NH4 Urea (waste) Dietary Protein Amino Acids Carbon Glucose backbone (energy) Intracellular Protein Argininemia and the Urea Cycle ● Disorder of the urea cycle ● Our bodies produce ammonia as metabolic waste - Ammonia is highly toxic and must be discarded ● The urea cycle in the liver converts ammonia to urea, a less toxic compound Urea Cycle. Digital image retrieved October 31, 2018 from https://www.slideshare.net/YESANNA/urea-cycle-44200147 What is Argininemia? ● Disorder of the urea cycle ● Dysfunctional arginase enzyme disrupts final step of urea cycle ● Build-up of ammonia in the blood X Urea Cycle.
    [Show full text]
  • Three Classes of Tetrahydrobiopterin-Dependent Enzymes
    DOI 10.1515/pterid-2013-0003 Pteridines 2013; 24(1): 7–11 Review Ernst R. Werner* Three classes of tetrahydrobiopterin-dependent enzymes Abstract: Current knowledge distinguishes three classes in Antalya, Turkey. For a more detailed review on bio- of tetrahydrobiopterin-dependent enzymes as based on chemistry and pathophysiology of tetrahydrobio pterin, protein sequence similarity. These three protein sequence the reader is referred to Ref. [ 1 ]. Here, a short historical clusters hydroxylate three types of substrate atoms and overview of the discovery of tetrahydrobiopterin-depend- use three different forms of iron for catalysis. The first ent enzymes is presented, followed by a summary of the class to be discovered was the aromatic amino acid biochemical properties of these enzymes. The reactions hydroxylases, which, in mammals, include phenylalanine catalyzed by the three classes of tetrahydrobiopterin- hydroxylase, tyrosine hydroxylase, and two isoforms of dependent enzymes are detailed in Figure 1 . tryptophan hydroxylases. The protein sequences of these tetrahydrobiopterin-dependent aromatic amino acid hydroxylases are significantly similar, and all mammalian Discovery of tetrahydrobiopterin- aromatic amino acid hydroxylases require a non-heme- dependent enzymes bound iron atom in the active site of the enzyme for cataly- sis. The second classes of tetrahydrobiopterin-dependent enzymes to be characterized were the nitric oxide syn- Aromatic amino acid hydroxylases thases, which in mammals occur as three isoforms. Nitric oxide synthase protein sequences form a separate cluster Phenylalanine hydroxylase was the first enzyme charac- of homologous sequences with no similarity to aromatic terized to be dependent on a tetrahydropterin [ 2 ]. It then amino acid hydroxylase protein sequences. In contrast to took five more years to identify the nature of the endo- aromatic amino acid hydroxylases, nitric oxide synthases genous cofactor as tetrahydrobiopterin [ 3 ].
    [Show full text]