title: Controllable expansion of primary cardiomyocytes by reversible immortalization.
abstract: Cardiac tissue engineering will remain only a prospect unless large numbers of therapeutic cells can be provided, either from small samples of cardiac cells or from stem cell sources. In contrast to most adult cells, cardiomyocytes are terminally differentiated and cannot be expanded in culture. We explored the feasibility of enabling the in vitro expansion of primary neonatal rat cardiomyocytes by lentivector-mediated cell immortalization, and then reverting the phenotype of the expanded cells back to the cardiomyocyte state. Primary rat cardiomyocytes were transduced with simian virus 40 large T antigen (TAg), or with Bmi-1 followed by the human telomerase reverse transcriptase (hTERT) gene; the cells were expanded; and the transduced genes were removed by adenoviral vector expressing Cre recombinase. The TAg gene was more efficient in cell transduction than the Bmi-1/hTERT gene, based on the rate of cell proliferation. Immortalized cells exhibited the morphological features of dedifferentiation (increased vimentin expression, and reduced expression of troponin I and Nkx2.5) along with the continued expression of cardiac markers (alpha-actin, connexin-43, and calcium transients). After the immortalization was reversed, cells returned to their differentiated state. This strategy for controlled expansion of primary cardiomyocytes by gene transfer has potential for providing large amounts of a patient's own cardiomyocytes for cell therapy, and the cardiomyocytes derived by this method could be a useful cellular model by which to study cardiogenesis.
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Edem
authors.initials: E
authors.lastname: Nuglozeh
authors.forename: Fatouma
authors.initials: F
authors.lastname: Touré
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Schmidt
authors.forename: Gordana
authors.initials: G
authors.lastname: Vunjak-Novakovic
mesh_terms: D000199:Actins / Q000096:biosynthesis; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics; D002454:Cell Differentiation; D002461:Cell Line, Transformed; D018031:Connexin 43 / Q000096:biosynthesis; D006678:HIV / Q000235:genetics; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000096:biosynthesis; D006801:Humans; D019426:Integrases / Q000235:genetics; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000502:physiology* / Q000637:transplantation; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D063150:Polycomb Repressive Complex 1; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051381:Rats; D012097:Repressor Proteins / Q000235:genetics; D019098:Telomerase / Q000235:genetics; D023822:Tissue Engineering / Q000379:methods*; D014157:Transcription Factors / Q000096:biosynthesis; D014161:Transduction, Genetic; D014336:Troponin / Q000096:biosynthesis
chemical_list: D000199:Actins; D000952:Antigens, Polyomavirus Transforming; C069077:BMI1 protein, human; D018031:Connexin 43; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C524161:Nkx2-5 protein, rat; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D014336:Troponin; D063150:Polycomb Repressive Complex 1; C045073:Cre recombinase; D019426:Integrases; D019098:Telomerase