title: Bcl-2 improves myoblast sheet therapy in rat chronic heart failure.
abstract: Myoblast transplantation therapy for chronic heart failure (HF) is impaired by early donor cell death and reduced graft viability. Although epicardial implantation of cell sheets can prevent the initial loss of transplanted cells, limited vascularization subjects the sheets to apoptotic stress. We studied the efficacy of antiapoptotic bcl2 in myoblast sheet therapy for rat chronic HF. Myocardial infarction was induced by left anterior descending coronary artery ligation and HF was allowed to develop for 4 weeks. Thereafter, wild type (L6-WT; n=16) or Bcl-2-expressing (L6-Bcl2; n=19) myoblast sheets were transplanted epicardially. Control rats (n=21) underwent left anterior descending coronary artery ligation and re-thoracotomy. Five rats were sham-operated in both surgeries. Four weeks after transplantation, only the L6-Bcl2 rats showed improved left ventricular ejection fraction. Their vascular density in the damaged myocardium was greater, and they had more proliferating cells. The L6-Bcl2 group had an increased amount of myocytes in the infarct area. Soluble factors from L6-Bcl2 sheets induced a 2.9-fold increase in endothelial cell proliferation, and enhanced endothelial wound healing as compared to the L6-WT sheets. These effects were inhibited by SU5416 and were thus dependent on Flt1/Flk1 signaling. In conclusion, bcl2 improves efficacy of myoblast sheet transplantation and promotes proangiogenic paracrine signaling.
authors.affiliation: Institute of Biomedicine, Pharmacology, Biomedicum, University of Helsinki, and Department of Cardiothoracic Surgery, Helsinki University Meilahti Hospital, Helsinki, Finland. antti.siltanen@helsinki.fi
authors.forename: Antti
authors.initials: A
authors.lastname: Siltanen
authors.forename: Katsukiyo
authors.initials: K
authors.lastname: Kitabayashi
authors.forename: Tommi
authors.initials: T
authors.lastname: Pätilä
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ono
authors.forename: Ilkka
authors.initials: I
authors.lastname: Tikkanen
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Sawa
authors.forename: Esko
authors.initials: E
authors.lastname: Kankuri
authors.forename: Ari
authors.initials: A
authors.lastname: Harjula
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004452:Echocardiography; D042783:Endothelial Cells / Q000166:cytology; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D032446:Myoblasts / Q000166:cytology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014470:Umbilical Cord / Q000166:cytology; D014945:Wound Healing / Q000502:physiology
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2