title: Regeneration of the infarcted heart with stem cells derived by nuclear transplantation.
abstract: Nuclear transfer techniques have been proposed as a strategy for generating an unlimited supply of rejuvenated and histocompatible stem cells for the treatment of cardiac diseases. For this purpose, c-kit-positive fetal liver stem cells obtained from cloned embryos were injected in the border zone of infarcted mice to induce tissue reconstitution. Cloned embryos were derived from somatic cell fusion between nuclei of cultured LacZ-positive fibroblasts and enucleated oocytes of a different mouse strain. We report that regenerating myocardium replaced 38% of the scar at 1 month. The rebuilt tissue expressed LacZ and was composed of myocytes and vessels connected with the coronary circulation. Myocytes were functionally competent and expressed contractile proteins, desmin, connexin43, and N-cadherin. These structural characteristics indicated that the new myocytes were electrically and mechanically coupled. Similarly, the formed coronary arterioles and capillary structures contained blood and contributed, therefore, to tissue oxygenation. Cardiac replacement resulted in an improvement of ventricular hemodynamics and in a reduction of diastolic wall stress. These beneficial effects were obtained by stem cell transdifferentiation and commitment to the cardiac cell lineages. Myocardial growth was independent from fusion of the injected stem cells with preexisting partner cells. In conclusion, c-kit-positive stem cells derived by nuclear transfer cloning restore infarcted myocardium. Although problems currently plague nuclear transplantation, including the potential for epigenetic and imprinting abnormalities, stem cells derived from cloned embryos are sufficiently normal to repair damaged tissue in vivo. Importantly, the magnitude of myocardial regeneration obtained in this study is significantly superior to that achieved with adult bone marrow cells.
authors.affiliation: Advanced Cell Technology, Worcester, Mass, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Lanza
authors.forename: Malcolm A S
authors.initials: MA
authors.lastname: Moore
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Wakayama
authors.forename: Anthony C F
authors.initials: AC
authors.lastname: Perry
authors.forename: Jae-Hung
authors.initials: JH
authors.lastname: Shieh
authors.forename: Jan
authors.initials: J
authors.lastname: Hendrikx
authors.forename: Annarosa
authors.initials: A
authors.lastname: Leri
authors.forename: Stefano
authors.initials: S
authors.lastname: Chimenti
authors.forename: Alyssa
authors.initials: A
authors.lastname: Monsen
authors.forename: Daria
authors.initials: D
authors.lastname: Nurzynska
authors.forename: Michael D
authors.initials: MD
authors.lastname: West
authors.forename: Jan
authors.initials: J
authors.lastname: Kajstura
authors.forename: Piero
authors.initials: P
authors.lastname: Anversa
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D002459:Cell Fusion; D048429:Cell Size; D002999:Clone Cells / Q000637:transplantation*; D019976:Cloning, Organism; D005260:Female; D016332:Fetal Tissue Transplantation; D005347:Fibroblasts / Q000648:ultrastructure; D017930:Genes, Reporter; D006321:Heart / Q000502:physiology*; D007267:Injections; D007763:Lac Operon; D008099:Liver / Q000166:cytology / Q000196:embryology; D008297:Male; D051379:Mice; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D032383:Myocytes, Cardiac / Q000166:cytology; D018919:Neovascularization, Physiologic; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000648:ultrastructure; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D012038:Regeneration; D033581:Stem Cell Transplantation; D014463:Ultrasonography
chemical_list: D019009:Proto-Oncogene Proteins c-kit