title: AAV6-mediated Cardiac-specific Overexpression of Ribonucleotide Reductase Enhances Myocardial Contractility.
abstract: Impaired systolic function, resulting from acute injury or congenital defects, leads to cardiac complications and heart failure. Current therapies slow disease progression but do not rescue cardiac function. We previously reported that elevating the cellular 2 deoxy-ATP (dATP) pool in transgenic mice via increased expression of ribonucleotide reductase (RNR), the enzyme that catalyzes deoxy-nucleotide production, increases myosin-actin interaction and enhances cardiac muscle contractility. For the current studies, we initially injected wild-type mice retro-orbitally with a mixture of adeno-associated virus serotype-6 (rAAV6) containing a miniaturized cardiac-specific regulatory cassette (cTnT(455)) composed of enhancer and promotor portions of the human cardiac troponin T gene (TNNT2) ligated to rat cDNAs encoding either the Rrm1 or Rrm2 subunit. Subsequent studies optimized the system by creating a tandem human RRM1-RRM2 cDNA with a P2A self-cleaving peptide site between the subunits. Both rat and human Rrm1/Rrm2 cDNAs resulted in RNR enzyme overexpression exclusively in the heart and led to a significant elevation of left ventricular (LV) function in normal mice and infarcted rats, measured by echocardiography or isolated heart perfusions, without adverse cardiac remodeling. Our study suggests that increasing RNR levels via rAAV-mediated cardiac-specific expression provide a novel gene therapy approach to potentially enhance cardiac systolic function in animal models and patients with heart failure.
authors.affiliation: Mitochondria and Metabolism Center, University of Washington, Seattle, Washington, USA.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Kolwicz
authors.affiliation: Department of Neurology, University of Washington, Seattle, Washington, USA.
authors.forename: Guy L
authors.initials: GL
authors.lastname: Odom
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington, USA.
authors.forename: Sarah G
authors.initials: SG
authors.lastname: Nowakowski
authors.affiliation: Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Farid
authors.initials: F
authors.lastname: Moussavi-Harami
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, Washington, USA.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Hans
authors.initials: H
authors.lastname: Reinecke
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, Washington, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Hauschka
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington, USA; Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, USA; Department of Pathology, University of Washington, Seattle, Washington, USA; Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Murry
authors.affiliation: BEAT Biotherapeutics Corp., Seattle, Washington, USA. Electronic address: gmahairas@comcast.net.
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Mahairas
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington, USA; Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA. Electronic address: mregnier@uw.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Regnier
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics*; D004195:Disease Models, Animal; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000008:administration & dosage; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D051379:Mice; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000503:physiopathology / Q000628:therapy*; D009928:Organ Specificity; D051381:Rats; D012262:Ribonucleoside Diphosphate Reductase / Q000235:genetics; D012264:Ribonucleotide Reductases / Q000235:genetics*; D020107:Troponin T / Q000235:genetics*
chemical_list: C545568:TNNT2 protein, human; D020107:Troponin T; D012264:Ribonucleotide Reductases; C093713:ribonucleotide reductase M2; D012262:Ribonucleoside Diphosphate Reductase