title: S100A1 gene transfer: a strategy to strengthen engineered cardiac grafts.
abstract: BACKGROUND
  Cardiac tissue replacement therapy, although a promising novel approach for the potential treatment of heart failure, still suffers from insufficient contractile support to the failing myocardium. Here, we explore a strategy to improve contractile properties of engineered heart tissue (EHT) by S100A1 gene transfer.
  
  
  METHODS
  EHTs were generated from neonatal rat cardiomyocytes and transfected (MOI 10 PFU) with the S100A1 adenovirus (AdvS100A1, n = 25) while an adenovirus devoid of the S100A1 cDNA served as a control (AdvGFP, n = 30). Contractile properties of transfected EHTs were measured 7 days following gene transfer.
  
  
  RESULTS
  Western blot analysis confirmed a 8.7 +/- 3.6-fold S100A1 protein overexpression in AdvS100A1-transfected EHTs (n = 4; P < 0.01) that increased maximal isometric force (mN; AdvGFP 0.175 +/- 0.03 vs. AdvS100A1 0.47 +/- 0.06; P < 0.05) at 0.4 mmol/L extracellular calcium concentration [Ca(2+)](e). In addition, S100A1 overexpression enhanced both maximal Ca(2+)-stimulated force generation (+81%; P < 0.05) and Ca(2+)-sensitivity of EHTs (EC50% [Ca(2+)](e) mM; AdvGFP 0.33 +/- 0.04 vs. AdvS100A1 0.21 +/- 0.0022; P < 0.05). The S100A1-mediated gain in basal graft contractility was preserved throughout a series of isoproterenol interventions (10(-9) to 10(-6) M). Physiological properties of EHTs resembling intact heart preparations were preserved.
  
  
  CONCLUSIONS
  S100A1 gene transfer in EHT is feasible and augments contractile performance, while characteristic physiological features of EHT remain unchanged. Thus, specific genetic manipulation of tissue constructs prior to implantation should be part of an improved tissue replacement strategy in heart failure.
authors.affiliation: Medizinische Klinik III, Universität Heidelberg, 69115 Heidelberg, Germany. andrew.remppis@med.uni-heidelberg.de
authors.forename: Andrew
authors.initials: A
authors.lastname: Remppis
authors.forename: Sven T
authors.initials: ST
authors.lastname: Pleger
authors.forename: Patrick
authors.initials: P
authors.lastname: Most
authors.forename: Jan
authors.initials: J
authors.lastname: Lindenkamp
authors.forename: Philipp
authors.initials: P
authors.lastname: Ehlermann
authors.forename: Christopher
authors.initials: C
authors.lastname: Schweda
authors.forename: Eva
authors.initials: E
authors.lastname: Löffler
authors.forename: Dieter
authors.initials: D
authors.lastname: Weichenhan
authors.forename: Wolfram
authors.initials: W
authors.lastname: Zimmermann
authors.forename: Thomas
authors.initials: T
authors.lastname: Eschenhagen
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Koch
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Katus
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D018014:Gene Transfer Techniques; D007537:Isometric Contraction / Q000235:genetics; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000235:genetics; D009206:Myocardium; D032383:Myocytes, Cardiac / Q000166:cytology / Q000502:physiology; D051381:Rats; D009418:S100 Proteins; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D000318:Adrenergic beta-Agonists; D002135:Calcium-Binding Proteins; D009418:S100 Proteins; C110294:S100A1 protein; D007545:Isoproterenol; D002118:Calcium