DOCSLIB.ORG

The Role of Pyruvate Dehydrogenase Kinase 4

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Role of Pyruvate Dehydrogenase Kinase 4 THE ROLE OF PYRUVATE DEHYDROGENASE KINASE 4 (PDK4) GENE MUTATION IN THE IMPAIRMENT OF METABOLIC FLEXIBILITY AND DEVELOPMENT OF DILATED CARDIOMYOPATHY IN DOBERMAN PINSCHERS By LUIZ BOLFER A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2018 © 2018 Luiz Bolfer This work is dedicated to my wife, Lillian, who has been a constant source of support and encouragement during the challenges of graduate school and life. I am truly thankful for having you in my life. This work is also dedicated to my parents, Jose Luiz and Elisabete, who have always loved me unconditionally and whose good examples have taught me to work hard for the things that I aspire to achieve. ACKNOWLEDGMENTS I would like to first thank my primary advisors Dr. Amara Estrada, and Dr. Christina Pacak, for their constant encouragement and support during this long road and huge step on the development of my career. I also would like to thank the University of Florida (UF) Veterinary Clinical Sciences program, and Dr. Ammon Peck and Mrs. Sally O’Connell in the Office of Graduate Studies and Research – I thank you for working to negotiate the logistics of my program and for providing me with the support needed to see my dissertation research through to completion. Furthermore, I would like to thank each of my committee members, Drs. Barry Byrne, Christina Pacak, Naohiro Terada, Peter Stacpoole, Thomas Conlon, and Thomas Vickroy. I thank you all for the expertise, encouragement, and enduring optimism every step of the way. Special thank you to Dr. Pacak for allowing me to develop my project at her laboratory and for spending countless hours helping me troubleshoot the methods – answering my questions at all hours of the days, and even weekends. I cannot thank Dr. Pacak enough for the time and energy she devoted to assisting with my research, and I thoroughly enjoyed being a part of her laboratory team. Many individuals at the University of Florida, College of Veterinary Medicine also touched my life, both personally and professionally, and helped me get to where I am today. Lastly, I would like to thank my parents Jose Luiz and Elisabete, and my brother Guilherme, and Sister Caroline. I am so grateful for the love and encouragement they have always shown me and for their belief in my ability to achieve anything I put my 4 mind to. I also could not have achieved this accomplishment without the patient, understanding, and loving support of my wife, Lillian. She helped to pull me through this experience – sharing in my successes but also bearing the brunt of my stress and frustrations. Lillian encouraged me to push forward and preserve and kept me focused on the end result, and for lending her ear when I needed to vent, and for her snuggles when it was time to procrastinate. Finally, I would like to thank my daughter Lydia, and my son Leonardo, even though they are too young to understand what Daddy went through, they have already changed completely the meaning of my life moving forward. 5 TABLE OF CONTENTS ACKNOWLEDGMENTS ...................................................................................................... 4 LIST OF TABLES ................................................................................................................ 8 LIST OF FIGURES .............................................................................................................. 9 LIST OF ABBREVIATIONS ............................................................................................... 10 CHAPTER 1 INTRODUCTION ........................................................................................................ 13 Familial DCM in DPs ................................................................................................... 14 Similarities to Human DCM Have Led to Several Studies Looking for a Possible Causative Gene in Canines ........................................................................................ 15 Impaired Myocardial Energy Metabolism and Mitochondrial Dysfunction Has Been Associated with DCM in DPs ............................................................................ 16 The Pivotal Role of Pyruvate Dehydrogenase Kinase 4 in Myocardial Fatty Acid and Glucose Oxidation ............................................................................................... 17 Pyruvate Dehydrogenase and the Connection Between Cardiac Remodeling, Metabolic Activity Shift, and Heart Failure ................................................................. 20 Regulation of Pyruvate Dehydrogenase Complex in the Heart Is Dependent on PDK4 as well as PDK2 ............................................................................................... 22 2 A MUTATION IN THE PDK4 GENE LEADS TO A DECREASE GENE EXPRESSION OF EXONS 10 AND 11...................................................................... 25 Materials and Methods ............................................................................................... 29 Animals ................................................................................................................. 30 Inclusion Criteria ................................................................................................... 30 Exclusion Criteria ................................................................................................. 30 Echocardiography ................................................................................................ 31 Holter Recordings................................................................................................. 31 Harvesting of Fibroblasts ..................................................................................... 32 Extracting RNA for PCR ....................................................................................... 32 Quantitative PCR.................................................................................................. 32 Statistical Analysis................................................................................................ 33 Results ........................................................................................................................ 33 Signalment ............................................................................................................ 33 Cardiac Evaluations ............................................................................................. 33 PCR Results ......................................................................................................... 34 Discussion ................................................................................................................... 35 3 A MUTATION IN THE PDK4 GENE LEADS TO A DECREASED EXPRESSION OF PDK4 PROTEIN AND DISRRUPTION OF THE C-TERMINAL DOMAIN .......... 47 6 Materials and Methods ............................................................................................... 48 Enzyme-Linked Immunosorbent Assay (ELISA) ................................................. 48 Statistical Analysis................................................................................................ 49 Results ........................................................................................................................ 49 Discussion ................................................................................................................... 49 4 PYRUVATE DEHYDROGENASE COMPLEX PROTEIN EXPRESSION AND FUNCTION ARE ALTERED IN CANINES WITH PDK4 MUTATION ....................... 55 Materials and Methods ............................................................................................... 58 ELISA Assays ....................................................................................................... 58 Statistical Analysis................................................................................................ 59 Results ........................................................................................................................ 60 Discussion ................................................................................................................... 62 5 PRIMARY SKIN FIBROBLAST ABUNDANCE, MORPHOLOGY AND CYTOSKELETAL STRUCTURE UPON STARVATION IN DIFFERENT PDK4 MUTANT CONDITIONS. ............................................................................................ 69 Materials and Methods ............................................................................................... 72 Fibroblast Isolation and Culture ........................................................................... 72 Viability Assays .................................................................................................... 72 Immunofluorescence ............................................................................................ 72 Data Processing ................................................................................................... 73 Results ........................................................................................................................ 73 Discussion ................................................................................................................... 75 6 MITOCHONDRIA OF MUTANT DOBERMAN PINSCHERS HAVE LOWER METABOLIC POTENTIAL AND FUNCTION ............................................................. 80 Materials and Methods ..............................................................................................
Load more

Recommended publications
  • NICU Gene List Generator.Xlsx
    Neonatal Crisis Sequencing Panel Gene List Genes: A2ML1 - B3GLCT A2ML1 ADAMTS9 ALG1 ARHGEF15 AAAS ADAMTSL2 ALG11 ARHGEF9 AARS1 ADAR ALG12 ARID1A AARS2 ADARB1 ALG13 ARID1B ABAT ADCY6 ALG14 ARID2 ABCA12 ADD3 ALG2 ARL13B ABCA3 ADGRG1 ALG3 ARL6 ABCA4 ADGRV1 ALG6 ARMC9 ABCB11 ADK ALG8 ARPC1B ABCB4 ADNP ALG9 ARSA ABCC6 ADPRS ALK ARSL ABCC8 ADSL ALMS1 ARX ABCC9 AEBP1 ALOX12B ASAH1 ABCD1 AFF3 ALOXE3 ASCC1 ABCD3 AFF4 ALPK3 ASH1L ABCD4 AFG3L2 ALPL ASL ABHD5 AGA ALS2 ASNS ACAD8 AGK ALX3 ASPA ACAD9 AGL ALX4 ASPM ACADM AGPS AMELX ASS1 ACADS AGRN AMER1 ASXL1 ACADSB AGT AMH ASXL3 ACADVL AGTPBP1 AMHR2 ATAD1 ACAN AGTR1 AMN ATL1 ACAT1 AGXT AMPD2 ATM ACE AHCY AMT ATP1A1 ACO2 AHDC1 ANK1 ATP1A2 ACOX1 AHI1 ANK2 ATP1A3 ACP5 AIFM1 ANKH ATP2A1 ACSF3 AIMP1 ANKLE2 ATP5F1A ACTA1 AIMP2 ANKRD11 ATP5F1D ACTA2 AIRE ANKRD26 ATP5F1E ACTB AKAP9 ANTXR2 ATP6V0A2 ACTC1 AKR1D1 AP1S2 ATP6V1B1 ACTG1 AKT2 AP2S1 ATP7A ACTG2 AKT3 AP3B1 ATP8A2 ACTL6B ALAS2 AP3B2 ATP8B1 ACTN1 ALB AP4B1 ATPAF2 ACTN2 ALDH18A1 AP4M1 ATR ACTN4 ALDH1A3 AP4S1 ATRX ACVR1 ALDH3A2 APC AUH ACVRL1 ALDH4A1 APTX AVPR2 ACY1 ALDH5A1 AR B3GALNT2 ADA ALDH6A1 ARFGEF2 B3GALT6 ADAMTS13 ALDH7A1 ARG1 B3GAT3 ADAMTS2 ALDOB ARHGAP31 B3GLCT Updated: 03/15/2021; v.3.6 1 Neonatal Crisis Sequencing Panel Gene List Genes: B4GALT1 - COL11A2 B4GALT1 C1QBP CD3G CHKB B4GALT7 C3 CD40LG CHMP1A B4GAT1 CA2 CD59 CHRNA1 B9D1 CA5A CD70 CHRNB1 B9D2 CACNA1A CD96 CHRND BAAT CACNA1C CDAN1 CHRNE BBIP1 CACNA1D CDC42 CHRNG BBS1 CACNA1E CDH1 CHST14 BBS10 CACNA1F CDH2 CHST3 BBS12 CACNA1G CDK10 CHUK BBS2 CACNA2D2 CDK13 CILK1 BBS4 CACNB2 CDK5RAP2
    [Show full text]
  • Role of Tafazzin in Hematopoiesis and Leukemogenesis
    Role of Tafazzin in Hematopoiesis and Leukemogenesis by Ayesh Seneviratne A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Institute of Medical Science University of Toronto © Copyright by Ayesh Seneviratne 2020 Role of Tafazzin in Hematopoiesis and Leukemogenesis Ayesh Seneviratne Doctor of Philosophy Institute of Medical Science University of Toronto 2020 Abstract Tafazzin (TAZ) is a mitochondrial transacylase that remodels the mitochondrial cardiolipin into its mature form. Through a CRISPR screen, we identified TAZ as necessary for the growth and viability of acute myeloid leukemia (AML) cells. Genetic inhibition of TAZ reduced stemness and increased differentiation of AML cells both in vitro and in vivo. In contrast, knockdown of TAZ did not impair normal hematopoiesis under basal conditions. Mechanistically, inhibition of TAZ decreased levels of cardiolipin but also altered global levels of intracellular phospholipids, including phosphatidylserine, which controlled AML stemness and differentiation by modulating toll-like receptor (TLR) signaling (Seneviratne et al., 2019). ii Acknowledgments Firstly, I would like to thank Dr. Aaron Schimmer for his guidance and support during my PhD studies. I really enjoyed our early morning meetings where he provided much needed perspective to navigate the road blocks of my project, whilst continuing to push me. It was a privilege to be mentored by such an excellent clinician scientist. I hope to continue to build on the skills I learned in Dr. Schimmer’s lab as I progress on my path to become a clinician scientist. Working in the Schimmer lab was a wonderful learning environment. I would like to especially thank Dr.
    [Show full text]
  • Supplementary Table S4. FGA Co-Expressed Gene List in LUAD
    Supplementary Table S4. FGA co-expressed gene list in LUAD tumors Symbol R Locus Description FGG 0.919 4q28 fibrinogen gamma chain FGL1 0.635 8p22 fibrinogen-like 1 SLC7A2 0.536 8p22 solute carrier family 7 (cationic amino acid transporter, y+ system), member 2 DUSP4 0.521 8p12-p11 dual specificity phosphatase 4 HAL 0.51 12q22-q24.1histidine ammonia-lyase PDE4D 0.499 5q12 phosphodiesterase 4D, cAMP-specific FURIN 0.497 15q26.1 furin (paired basic amino acid cleaving enzyme) CPS1 0.49 2q35 carbamoyl-phosphate synthase 1, mitochondrial TESC 0.478 12q24.22 tescalcin INHA 0.465 2q35 inhibin, alpha S100P 0.461 4p16 S100 calcium binding protein P VPS37A 0.447 8p22 vacuolar protein sorting 37 homolog A (S. cerevisiae) SLC16A14 0.447 2q36.3 solute carrier family 16, member 14 PPARGC1A 0.443 4p15.1 peroxisome proliferator-activated receptor gamma, coactivator 1 alpha SIK1 0.435 21q22.3 salt-inducible kinase 1 IRS2 0.434 13q34 insulin receptor substrate 2 RND1 0.433 12q12 Rho family GTPase 1 HGD 0.433 3q13.33 homogentisate 1,2-dioxygenase PTP4A1 0.432 6q12 protein tyrosine phosphatase type IVA, member 1 C8orf4 0.428 8p11.2 chromosome 8 open reading frame 4 DDC 0.427 7p12.2 dopa decarboxylase (aromatic L-amino acid decarboxylase) TACC2 0.427 10q26 transforming, acidic coiled-coil containing protein 2 MUC13 0.422 3q21.2 mucin 13, cell surface associated C5 0.412 9q33-q34 complement component 5 NR4A2 0.412 2q22-q23 nuclear receptor subfamily 4, group A, member 2 EYS 0.411 6q12 eyes shut homolog (Drosophila) GPX2 0.406 14q24.1 glutathione peroxidase
    [Show full text]
  • Cloud-Clone 16-17
    Cloud-Clone - 2016-17 Catalog Description Pack Size Supplier Rupee(RS) ACB028Hu CLIA Kit for Anti-Albumin Antibody (AAA) 96T Cloud-Clone 74750 AEA044Hu ELISA Kit for Anti-Growth Hormone Antibody (Anti-GHAb) 96T Cloud-Clone 74750 AEA255Hu ELISA Kit for Anti-Apolipoprotein Antibodies (AAHA) 96T Cloud-Clone 74750 AEA417Hu ELISA Kit for Anti-Proteolipid Protein 1, Myelin Antibody (Anti-PLP1) 96T Cloud-Clone 74750 AEA421Hu ELISA Kit for Anti-Myelin Oligodendrocyte Glycoprotein Antibody (Anti- 96T Cloud-Clone 74750 MOG) AEA465Hu ELISA Kit for Anti-Sperm Antibody (AsAb) 96T Cloud-Clone 74750 AEA539Hu ELISA Kit for Anti-Myelin Basic Protein Antibody (Anti-MBP) 96T Cloud-Clone 71250 AEA546Hu ELISA Kit for Anti-IgA Antibody 96T Cloud-Clone 71250 AEA601Hu ELISA Kit for Anti-Myeloperoxidase Antibody (Anti-MPO) 96T Cloud-Clone 71250 AEA747Hu ELISA Kit for Anti-Complement 1q Antibody (Anti-C1q) 96T Cloud-Clone 74750 AEA821Hu ELISA Kit for Anti-C Reactive Protein Antibody (Anti-CRP) 96T Cloud-Clone 74750 AEA895Hu ELISA Kit for Anti-Insulin Receptor Antibody (AIRA) 96T Cloud-Clone 74750 AEB028Hu ELISA Kit for Anti-Albumin Antibody (AAA) 96T Cloud-Clone 71250 AEB264Hu ELISA Kit for Insulin Autoantibody (IAA) 96T Cloud-Clone 74750 AEB480Hu ELISA Kit for Anti-Mannose Binding Lectin Antibody (Anti-MBL) 96T Cloud-Clone 88575 AED245Hu ELISA Kit for Anti-Glutamic Acid Decarboxylase Antibodies (Anti-GAD) 96T Cloud-Clone 71250 AEK505Hu ELISA Kit for Anti-Heparin/Platelet Factor 4 Antibodies (Anti-HPF4) 96T Cloud-Clone 71250 CCA005Hu CLIA Kit for Angiotensin II
    [Show full text]
  • Prohibitins: a Critical Role in Mitochondrial Functions and Implication in Diseases
    cells Review Prohibitins: A Critical Role in Mitochondrial Functions and Implication in Diseases Anna Signorile 1,*, Giuseppe Sgaramella 2, Francesco Bellomo 3 and Domenico De Rasmo 4,* 1 Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy 2 Water Research Institute (IRSA), National Research Council (CNR), Viale F. De Blasio, 5, 70132 Bari, Italy; [email protected] 3 Laboratory of Nephrology, Department of Rare Diseases, Bambino Gesù Children’s Hospital, Viale di S. Paolo, 15, 00149 Rome, Italy; [email protected] 4 Institute of Biomembrane, Bioenergetics and Molecular Biotechnology (IBIOM), National Research Council (CNR), 70126 Bari, Italy * Correspondence: [email protected] (A.S.); [email protected] (D.D.R.); Tel.: +39-080-544-8516 (A.S. & D.D.R.) Received: 7 December 2018; Accepted: 15 January 2019; Published: 18 January 2019 Abstract: Prohibitin 1 (PHB1) and prohibitin 2 (PHB2) are proteins that are ubiquitously expressed, and are present in the nucleus, cytosol, and mitochondria. Depending on the cellular localization, PHB1 and PHB2 have distinctive functions, but more evidence suggests a critical role within mitochondria. In fact, PHB proteins are highly expressed in cells that heavily depend on mitochondrial function. In mitochondria, these two proteins assemble at the inner membrane to form a supra-macromolecular structure, which works as a scaffold for proteins and lipids regulating mitochondrial metabolism, including bioenergetics, biogenesis, and dynamics in order to determine the cell fate, death, or life. PHB alterations have been found in aging and cancer, as well as neurodegenerative, cardiac, and kidney diseases, in which significant mitochondrial impairments have been observed.
    [Show full text]
  • Phospholipids: Identification and Implication in Muscle Pathophysiology
    International Journal of Molecular Sciences Review Phospholipids: Identification and Implication in Muscle Pathophysiology Rezlène Bargui 1, Audrey Solgadi 2, Bastien Prost 2 ,Mélanie Chester 1, Ana Ferreiro 1,3 ,Jérôme Piquereau 4 and Maryline Moulin 1,* 1 Basic and Translational Myology Laboratory, CNRS UMR8251, Université de Paris, F-75013 Paris, France; [email protected] (R.B.); [email protected] (M.C.); [email protected] (A.F.) 2 UMS-IPSIT-SAMM, Université Paris-Saclay, INSERM, CNRS, Ingénierie et Plateformes au Service de l’Innovation Thérapeutique, F-92296 Châtenay-Malabry, France; [email protected] (A.S.); [email protected] (B.P.) 3 AP-HP, Reference Centre for Neuromuscular Disorders, Institute of Myology, Pitié-Salpêtrière Hospital, F-75013 Paris, France 4 Signalling and Cardiovascular Pathophysiology, INSERM UMR1180, Université Paris-Saclay, F-92296 Châtenay-Malabry, France; [email protected] * Correspondence: [email protected] Abstract: Phospholipids (PLs) are amphiphilic molecules that were essential for life to become cellular. PLs have not only a key role in compartmentation as they are the main components of membrane, but they are also involved in cell signaling, cell metabolism, and even cell pathophysiology. Considered for a long time to simply be structural elements of membranes, phospholipids are increasingly being viewed as sensors of their environment and regulators of many metabolic processes. After presenting their main characteristics, we expose the increasing methods of PL detection and identification that Citation: Bargui, R.; Solgadi, A.; help to understand their key role in life processes. Interest and importance of PL homeostasis is Prost, B.; Chester, M.; Ferreiro, A.; growing as pathogenic variants in genes involved in PL biosynthesis and/or remodeling are linked Piquereau, J.; Moulin, M.
    [Show full text]
  • A Phase 3 Randomized, Double-Blind
    SPIMM-301 Version 4.0 15 June 2018 Title: A Phase 3 Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Trial to Evaluate the Efficacy and Safety of Daily Subcutaneous Injections of Elamipretide in Subjects with Primary Mitochondrial Myopathy Followed by an Open-Label Treatment Extension NCT: NCT03323749 Final Approval Date: 15 June 2018 Stealth BioTherapeutics Inc. CONFIDENTIAL 1 00900-4.00 SPIMM-301 Version 4.0 15 June 2018 CLINICAL TRIAL PROTOCOL A Phase 3 Randomized, Double-Blind, Parallel-Group, Placebo- Controlled Trial to Evaluate the Efficacy and Safety of Daily Subcutaneous Injections of Elamipretide in Subjects with Primary Mitochondrial Myopathy Followed by an Open-Label Treatment Extension Trial Phase: Phase 3 Trial Number: SPIMM-301 Document Version: Version 4.0 Final Approval Date: 15 June 2018 IND Number: 123,553 EudraCT Number: 2017-002447-15 Sponsor: Stealth BioTherapeutics Inc. 275 Grove Street, Suite 3-107 Newton, MA 02466 United States of America (USA) Sponsor Chief Clinical Jim Carr, Pharm.D. Development Officer: Chief Clinical Development Officer 275 Grove Street 3-107, Newton, MA 02466, USA [email protected] +1 617-762-2503 Sponsor Medical Monitor: Sandrin Bergheanu, M.D., Ph.D Medical Monitor 275 Grove Street 3-107, Newton, MA 02466, USA [email protected] +1 617-762-2595 +31 (0) 641 476 460 Confidentiality Statement The information contained in this document is confidential and is the property of Stealth BioTherapeutics Inc. No part of it may be transmitted, reproduced, published, or
    [Show full text]
  • Genetic Testing Medical Policy – Genetics
    Genetic Testing Medical Policy – Genetics Please complete all appropriate questions fully. Suggested medical record documentation: • Current History & Physical • Progress Notes • Family Genetic History • Genetic Counseling Evaluation *Failure to include suggested medical record documentation may result in delay or possible denial of request. PATIENT INFORMATION Name: Member ID: Group ID: PROCEDURE INFORMATION Genetic Counseling performed: c Yes c No **Please check the requested analyte(s), identify number of units requested, and provide indication/rationale for testing. 81400 Molecular Pathology Level 1 Units _____ c ACADM (acyl-CoA dehydrogenase, C-4 to C-12 straight chain, MCAD) (e.g., medium chain acyl dehydrogenase deficiency), K304E variant _____ c ACE (angiotensin converting enzyme) (e.g., hereditary blood pressure regulation), insertion/deletion variant _____ c AGTR1 (angiotensin II receptor, type 1) (e.g., essential hypertension), 1166A>C variant _____ c BCKDHA (branched chain keto acid dehydrogenase E1, alpha polypeptide) (e.g., maple syrup urine disease, type 1A), Y438N variant _____ c CCR5 (chemokine C-C motif receptor 5) (e.g., HIV resistance), 32-bp deletion mutation/794 825del32 deletion _____ c CLRN1 (clarin 1) (e.g., Usher syndrome, type 3), N48K variant _____ c DPYD (dihydropyrimidine dehydrogenase) (e.g., 5-fluorouracil/5-FU and capecitabine drug metabolism), IVS14+1G>A variant _____ c F13B (coagulation factor XIII, B polypeptide) (e.g., hereditary hypercoagulability), V34L variant _____ c F2 (coagulation factor 2) (e.g.,
    [Show full text]
  • TAFAZZIN Gene Tafazzin
    TAFAZZIN gene tafazzin Normal Function The TAFAZZIN gene provides instructions for producing a protein called tafazzin. Several different versions (isoforms) of the tafazzin protein are produced from the TAFAZZIN gene. Most isoforms are found in all tissues, but some are found only in certain types of cells. The tafazzin protein is located in structures called mitochondria, which are the energy-producing centers of cells. Tafazzin is involved in altering a fat ( lipid) called cardiolipin, which plays critical roles in the mitochondrial inner membrane. The tafazzin protein adds a fatty acid called linoleic acid to the cardiolipin molecule, which enables cardiolipin to perform its functions. Cardiolipin is necessary for maintaining mitochondrial shape, energy production, and protein transport within cells. Health Conditions Related to Genetic Changes Barth syndrome More than 130 mutations in the TAFAZZIN gene have been found to cause Barth syndrome. This rare condition occurs almost exclusively in males and is characterized by a weakened heart (cardiomyopathy), muscle weakness, recurrent infections, and short stature. TAFAZZIN gene mutations that cause Barth syndrome result in the production of tafazzin proteins with little or no function. As a result, linoleic acid is not added to cardiolipin, which results in a reduction of functional cardiolipin. In addition, a variant of cardiolipin called monolysocardiolipin (MLCL) is formed. A lack of functional cardiolipin and an excess of MLCL are thought to cause problems with normal mitochondrial shape and functions such as energy production and protein transport. Tissues with high energy demands, such as the heart and other muscles, are most susceptible to cell death due to reduced energy production in mitochondria.
    [Show full text]
  • Understanding the Role of MLCL AT-1 and Tafazzin in Mitochondrial Function
    Understanding the Role of MLCL AT-1 and Tafazzin in Mitochondrial Function by Edgard Marcello Mejia A Thesis submitted to the Faculty of Graduate Studies of the University of Manitoba in partial fulfillment of the requirements of the degree of Doctor of Philosophy Department of Pharmacology and Therapeutics University of Manitoba Copyright © 2016 Edgard Marcello Mejia Abstract Cardiolipin (CL) is a phospholipid found exclusively in mitochondria and is required for normal mitochondrial function. CL biosynthesis requires a crucial remodelling step that incorporates specific acyl chains onto its molecular structure. The enzyme primarily responsible for CL remodelling is Tafazzin (TAZ), a mitochondrial protein encoded by the TAZ gene localized to chromosome Xq28.12. Mutations on the TAZ gene result in a rare yet severe disease known as Barth Syndrome (BTHS). BTHS is characterized by symptoms that include cardiomyopathies, neutropenia and skeletal myopathies. The mitochondrial enzyme Monolysocardiolipin Acyltransferase -1 (MLCL AT-1) also exhibits the ability to remodel CL with specific acyl chains. The aims of our study were to 1) determine if a relationship exists between TAZ and MLCL AT-1 , 2) determine if MLCL AT-1 expression in BTHS lymphoblasts leads to improvements in mitochondrial function, and 3) to use the Taz knockdown (KD) mouse model to get a better understanding of the phenotypes displayed by BTHS patients. Our results showed that in normal healthy lymphoblasts, expression of MLCL AT-1 was inversely dependent on TAZ expression. However, in BTHS lymphoblasts, expression of MLCL AT-1 was significantly lower compared to healthy controls. With the use of a MLCL AT- 1-carrying plasmid, we expressed MLCL AT-1 in BTHS cells.
    [Show full text]
  • Diminished Exercise Capacity and Mitochondrial Bc1 Complex Deficiency in Tafazzin-Knockdown Mice
    ORIGINAL RESEARCH ARTICLE published: 17 April 2013 doi: 10.3389/fphys.2013.00074 Diminished exercise capacity and mitochondrial bc1 complex deficiency in tafazzin-knockdown mice Corey Powers,Yan Huang, Arnold Strauss and Zaza Khuchua* Division of Molecular Cardiovascular Biology, Cincinnati Children’s Medical Center, Cincinnati, OH, USA Edited by: The phospholipid, cardiolipin, is essential for maintaining mitochondrial structure and opti- Sabzali Javadov, University of Puerto mal function. Cardiolipin-deficiency in humans, Barth syndrome, is characterized by exer- Rico School of Medicine, Puerto Rico cise intolerance, dilated cardiomyopathy, neutropenia, and 3-methyl-glutaconic aciduria.The Reviewed by: Lawrence J. Prochaska, Wright State causative gene is the mitochondrial acyl-transferase, tafazzin, that is essential for remodel- University, USA ing acyl chains of cardiolipin. We sought to determine metabolic rates in tafazzin-deficient John Hollander, West Virginia mice during resting and exercise, and investigate the impact of cardiolipin-deficiency on University School of Medicine, USA mitochondrial respiratory chain activities. Tafazzin-knockdown in mice markedly impaired Andrey V. Kozlov, Ludwig Boltzmann Institute for Experimental and Clinical oxygen consumption rates during an exercise, without any significant effect on resting Traumatology, Austria metabolic rates. CL-deficiencyresulted in significant reduction of mitochondrial respiratory *Correspondence: reserve capacity in neonatal cardiomyocytes that is likely to be caused by diminished activ- Zaza Khuchua, Division of Molecular ity of complex-III, which requires CL for its assembly and optimal activity. Our results may Cardiovascular Biology, Cincinnati provide mechanistic insights of Barth syndrome pathogenesis. Children’s Hospital Medical Center,240 Albert Sabin Way, Keywords: Barth syndrome, tafazzin, complex-III, cardiolipins, exercise intolerance, mouse models S4.236,Cincinnati, OH 45229, USA.
    [Show full text]
  • Identification of a Novel TAZ Gene Mutation in a Family with X-Linked
    Original Manuscript Journal of Inborn Errors of Metabolism &Screening 1–5 Identification of a Novel TAZ Gene ª The Author(s) 2015 Reprints and permission: Mutation in a Family With X-Linked sagepub.com/journalsPermissions.nav DOI: 10.1177/2326409814567131 Dilated Cardiomyopathy Barth Syndrome iem.sagepub.com Minal Borkar, PhD1,2, Sunita Bijarnia-Mahay, DCH, DNB, MD1,3, Sudha Kohli, PhD1,3, Monica Juneja, MD4, Yogesh Srivastava, M.Sc5,6, Renu Saxena, PhD1,3, and Ishwar C. Verma, FRCP1,3 Abstract Mutations in the tafazzin (TAZ) gene on chromosome Xq28 are responsible for the Barth syndrome (BTHS) phenotype resulting in a loss of function in the protein tafazzin involved in the transacylation of cardiolipin, an essential mitochondrial phospholipid. TAZ gene was investigated in the proband in our study, who died of dilated cardiomyopathy at 8 months of age, and his family by sequencing to identify the genetic cause of BTHS. Molecular analysis revealed a novel mutation in exon 5 (c.520T>G) of the TAZ gene. This novel mutation c.520T>G, pW174G, was also found in female carriers (mother and grandmother of proband) in the family. Bioinformatic analysis was carried out to examine the effect of mutation in the gene and confirmed the deleterious effect of this single mutation to the protein structure. Protein modeling and 3-dimensional structure of TAZ protein demonstrated the significantly visible changes in mutated protein leading to BTHS phenotype. Prenatal diagnosis in a subsequent pregnancy showed a carrier female, and pregnancy was continued. Child is doing well at 1 year of age. Keywords Barth syndrome, TAZ gene, India, prenatal diagnosis, bioinformatic analyses Introduction identified.8 In the present study, we made a postmortem diag- nosis of BTHS in an infant who died of dilated cardiomyopathy Barth syndrome (BTHS; Online Mendelian Inheritance in Man with left ventricular (LV) noncompaction, based on family his- [OMIM] accession no.
    [Show full text]