title: Comparison of arrhythmogenicity and proinflammatory activity induced by intramyocardial or epicardial myoblast sheet delivery in a rat model of ischemic heart failure.
abstract: Although cell therapy of the failing heart by intramyocardial injections of myoblasts to results in regenerative benefit, it has also been associated with undesired and prospectively fatal arrhythmias. We hypothesized that intramyocardial injections of myoblasts could enhance inflammatory reactivity and facilitate electrical cardiac abnormalities that can be reduced by epicardial myoblast sheet delivery. In a rat model of ischemic heart failure, myoblast therapy either by intramyocardial injections or epicardial cell sheets was given 2 weeks after occlusion of the coronary artery. Ventricular premature contractions (VPCs) were assessed, using an implanted three-lead electrocardiograph at 1, 7, and 14 days after therapy, and 16-point epicardial electropotential mapping (EEPM) was used to evaluate ventricular arrhythmogenicity under isoproterenol stress. Cardiac functioning was assessed by echocardiography. Both transplantation groups showed therapeutic benefit over sham therapy. However, VPCs were more frequent in the Injection group on day 1 and day 14 after therapy than in animals receiving epicardial or sham therapy (p < 0.05 and p < 0.01, respectively). EEPM under isoproterenol stress showed macroreentry at the infarct border area, leading to ventricular tachycardias in the Injection group, but not in the myoblast sheet- or sham-treated groups (p = 0.045). Both transplantation types modified the myocardial cytokine expression profile. In animals receiving epicardial myoblast therapy, selective reductions in the expressions of interferon gamma, interleukin (IL)-1β and IL12 were observed, accompanied by reduced infiltration of inflammatory CD11b- and CD68-positive leukocytes, compared with animals receiving myoblasts as intramyocardial injections. Intramyocardial myoblast delivery was associated with enhanced inflammatory and immunomodulatory reactivity and increased frequency of VPCs. In comparison to intramyocardial injection, the epicardial route may serve as the preferred method of skeletal myoblast transplantation to treat heart failure.
authors: Department of Cardiothoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan; Department of Pediatric Cardiac Surgery, Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland.
authors: Tommi
authors: T
authors: Pätilä
authors: Department of Cardiothoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: Shigeru
authors: S
authors: Miyagawa
authors: Department of Cardiothoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: Yukiko
authors: Y
authors: Imanishi
authors: Department of Cardiothoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: Satsuki
authors: S
authors: Fukushima
authors: Pharmacology, University of Helsinki, Helsinki, Finland.
authors: Antti
authors: A
authors: Siltanen
authors: Pharmacology, University of Helsinki, Helsinki, Finland.
authors: Eero
authors: E
authors: Mervaala
authors: Pharmacology, University of Helsinki, Helsinki, Finland.
authors: Esko
authors: E
authors: Kankuri
authors: Department of Cardiothoracic Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors: Ari
authors: A
authors: Harjula
authors: Department of Cardiothoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: Yoshiki
authors: Y
authors: Sawa
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology*; D064987:Cell- and Tissue-Based Therapy / Q000009:adverse effects* / Q000379:methods*; D004195:Disease Models, Animal; D015870:Gene Expression; D006333:Heart Failure / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D032448:Myoblasts, Skeletal / Q000637:transplantation*; D009205:Myocarditis / Q000209:etiology*; D009206:Myocardium / Q000473:pathology; D010496:Pericardium / Q000473:pathology; D051381:Rats; D011917:Rats, Inbred Lew; D018879:Ventricular Premature Complexes / Q000209:etiology
chemical_list: D018836:Inflammation Mediators