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PII S1050-1738(05)00089-7 TCM Cardiac Stem and Progenitor Cell Biology for Regenerative Medicine Daniele Torella * , Georgina M. Ellison, Bernardo Nadal-Ginard, and Ciro Indolfi * Stem cell therapy is a new and promising treatment of heart disease. However, the race is still on to find the bbest Q cell to reconstitute the myocardium and improve function after myocardial damage. The recent discovery in the adult mammalian myocardium of a small cell population with the phenotype, behavior, and regenerative potential of cardiac stem and progenitor cells has proposed these cells as the most appropriate for cell therapy. The existence of these cells has provided an explanation for the hitherto unexplained existence of a subpopulation of immature cycling myocytes in the adult myocardium. These findings have placed the heart squarely among other organs with regenerative potential despite the fact that the working myocardium is mainly constituted of terminally differentiated cells. Although CSCs (cardiac cells proven to have stem and/or progenitor characteristics) can be isolated and amplified in vitro or stimulated to differentiate in situ, it has become reasonable to exploit this endogenous regenerative potential to replace the lost muscle with autologous functional myocardium. Therefore, it is imperative to obtain a better understanding of the biol- ogy and regenerative potential of the endogenous CSCs. This will enable us to design better protocols for the regeneration of functional con- tractile mass after myocardial injury. (Trends Cardiovasc Med 2005;15:229 – 236) D 2005, Elsevier Inc. Nowadays, the prevention and treat- ment of atherosclerotic heart disease have substantially reduced cardiovascu- lar morbidity. Nonetheless, once dam- age to the heart is established and heart failure is overt, no therapies can improve cardiac function in the long term (Jessup and Brozena 2003). Owing to the present era of regenerative med- icine and the recent excitement regard- ing stem cell therapies, attention has focused on the possibility of regenerat- ing myocardial tissue to treat cardiac diseases (Nadal-Ginard et al. 2003, Kor- bling and Estrov 2003). The majority of cardiac myocytes exit the cell cycle after a terminal round of Daniele Torella and Ciro Indolfi are at the Division of Cardiology, Magna Graecia Uni- versity, Catanzaro, Italy. Georgina M. Ellison and Bernardo Nadal-Ginard are at the Cardi- ovascular Institute, Mount Sinai School of Medicine, New York, New York. * Address correspondence to: Ciro Indolfi, MD, FACC, FESC, Professor of Cardiology and Daniele Torella, MD, are to be contacted at Laboratory of Molecular and Cellular Cardi- ology, Division of Cardiology, Department of Clinical and Experimental Medicine, Magna Graecia University, Via Tommaso Campa- nella, 115, Catanzaro 88100, Italy. Tel.: (+39) 0961-712-310; fax: (+39) 0961-712-445; e-mails: indolfi@unicz.it, dtorella@unicz.it. D 2005, Elsevier Inc. All rights reserved. 1050-1738/05/$-see front matter TCM Vol. 15, No. 6, 2005 229