title: Gene transfer of a phospholamban-targeted antibody improves calcium handling and cardiac function in heart failure.
abstract: BACKGROUND
  Abnormalities of intracellular calcium handling are widely recognized as a common hallmark of heart failure in animal models and humans. Modifying the interaction of phospholamban (PLB) with the sarcoplasmic reticulum ATPase (SERCA) by PLB mutants improves cardiac function but may also lead to heart failure. In this study we describe the in vivo effects of a new approach to modify the PLB-SERCA interaction using a recombinant, intracellularly expressed chicken-antibody derived protein (PLADP) targeting the cytoplasmic domain of PLB in the cardiomyopathic BIO 14.6 hamster.
  
  
  RESULTS
  In vivo gene transfer was performed in 12-14-week-old BIO 14.6 cardiomyopathic hamsters using intracoronary delivery of adenovirus containing the PLADP or the beta-galactosidase (LacZ) gene (8 x 10(9) PFU per animal). A third group was injected with saline (Sham). Echocardiography was performed before and, together with hemodynamic measurements, repeated 4-5 days after gene transfer. Indo-1 calcium transients and myocyte contractility were measured in isolated cardiomyocytes from the BIO 14.6 hamster transfected with the PLADP. Gene expression (LacZ) was found in 54+/-15% of cells throughout the heart without any signs of myocardial inflammation. Echocardiographic and hemodynamic indices of left ventricular function were significantly increased after gene transfer with the PLADP, compared to controls. Measurements of myocyte contractility and calcium transients in isolated cardiac myocytes from BIO 14.6 hamsters revealed improved intracellular calcium handling and contractility.
  
  
  CONCLUSIONS
  In vivo adenoviral gene transfer with the PLADP resulted in short-term intracellular expression of a PLADP, improving LV function and enhancing myocardial contractility in the failing cardiomyopathic hamster heart. The PLADP enhanced contractility and cardiac function by improving intracellular calcium handling. Expression of antibody-derived protein represents a new approach to modify protein-protein interactions at the cellular level.
authors.affiliation: Department of Medicine, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0618, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dieterle
authors.forename: Markus
authors.initials: M
authors.lastname: Meyer
authors.forename: Yusu
authors.initials: Y
authors.lastname: Gu
authors.forename: Darrell D
authors.initials: DD
authors.lastname: Belke
authors.forename: Eric
authors.initials: E
authors.lastname: Swanson
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Iwatate
authors.forename: John
authors.initials: J
authors.lastname: Hollander
authors.forename: Kirk L
authors.initials: KL
authors.lastname: Peterson
authors.forename: John
authors.initials: J
authors.lastname: Ross
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Dillmann
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000906:Antibodies / Q000235:genetics*; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000276:immunology*; D002645:Chickens; D006224:Cricetinae; D004452:Echocardiography; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000378:metabolism / Q000628:therapy*; D007116:Immunization, Passive / Q000379:methods; D008297:Male; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism*; D014161:Transduction, Genetic / Q000379:methods; D000099211:Phospholamban
chemical_list: D000906:Antibodies; D002118:Calcium; D002135:Calcium-Binding Proteins; D000099211:Phospholamban