title: Cardiac surgical delivery of the sarcoplasmic reticulum calcium ATPase rescues myocytes in ischemic heart failure.
abstract: BACKGROUND
  The sarcoplasmic reticulum calcium ATPase (SERCA2a) is an important molecular regulator of contractile dysfunction in heart failure. Gene transfer of SERCA2a mediated by molecular cardiac surgery with recirculating delivery (MCARD) is a novel and clinically translatable strategy.
  
  
  METHODS
  Ischemic heart failure was induced by ligation of OM1 and OM2 in 14 sheep. Seven sheep underwent MCARD-mediated AAV1-SERCA2a delivery 4 weeks after myocardial infarction, and seven sheep served as untreated controls. Magnetic resonance imaging-based mechanoenergetic studies were performed at baseline, 3 weeks, and 12 weeks after infarction. Myocyte apoptosis was quantified by Tdt-mediated nick-end labeling assay. Myocyte cross-sectional area and caspase-8 and caspase-9 activity was measured with imaging software, specific fluorogenic peptides, and immunohistochemistry.
  
  
  RESULTS
  MCARD-mediated AAV1-SERCA2a gene delivery resulted in robust cardiac-specific SERCA2a expression and stable improvements in global and regional contractility. There were significantly higher stroke volume index, left ventricular fractional thickening, and ejection fraction at 12 weeks in the MCARD group than in the control group (30 ± 3 vs 21 ± 2 mL/m(2); 12% ± 5% vs 3% ± 3%; and 43 ± 4 vs 32 ± 4, respectively, all p < 0.05). Apoptotic myocytes were observed more frequently in the control group than in the MCARD-SERCA2a group (0.57.2 ± 0.16 AU vs 0.32.4 ± 0.08 AU, p < 0.05). MCARD-SERCA2a also resulted in decreased caspase-8 and caspase-9 expression and decreased myocyte area in the border zone of transgenic sheep compared with control sheep (14.6% ± 1.2% vs 2.9% ± 0.7%; 18.2% ± 1.9% vs 8.6% ± 1.4%; and 102.1 ± 3.8 μm(2) vs 88.1 ± 3.6 μm(2), all p < 0.05).
  
  
  CONCLUSIONS
  MCARD-mediated SERCA2a delivery results in robust cardiac specific gene expression, improved contractility, and a decrease in both myocyte apoptosis and myocyte hypertrophy.
authors.affiliation: Sanger Heart & Vascular Institute, Carolinas Healthcare System, Charlotte, North Carolina, USA.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Fargnoli
authors.forename: Michael G
authors.initials: MG
authors.lastname: Katz
authors.forename: Charles
authors.initials: C
authors.lastname: Yarnall
authors.forename: Alice
authors.initials: A
authors.lastname: Isidro
authors.forename: Michael
authors.initials: M
authors.lastname: Petrov
authors.forename: Nury
authors.initials: N
authors.lastname: Steuerwald
authors.forename: Sriparna
authors.initials: S
authors.lastname: Ghosh
authors.forename: Kyle C
authors.initials: KC
authors.lastname: Richardville
authors.forename: Richard
authors.initials: R
authors.lastname: Hillesheim
authors.forename: Richard D
authors.initials: RD
authors.lastname: Williams
authors.forename: Erik
authors.initials: E
authors.lastname: Kohlbrenner
authors.forename: Hansell H
authors.initials: HH
authors.lastname: Stedman
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Hajjar
authors.forename: Charles R
authors.initials: CR
authors.lastname: Bridges
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006333:Heart Failure / Q000601:surgery*; D032383:Myocytes, Cardiac / Q000502:physiology; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000008:administration & dosage*; D012756:Sheep
chemical_list: D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases
keywords: 30