title: Innate heart regeneration: endogenous cellular sources and exogenous therapeutic amplification.
abstract: BACKGROUND
  The -once viewed as heretical- concept of the adult mammalian heart as a dynamic organ capable of endogenous regeneration has recently gained traction. However, estimated rates of myocyte turnover vary wildly and the underlying mechanisms of cardiac plasticity remain controversial. It is still unclear whether the adult mammalian heart gives birth to new myocytes through proliferation of resident myocytes, through cardiomyogenic differentiation of endogenous progenitors or through both mechanisms.
  
  
  METHODS
  In this review, the authors discuss the cellular origins of postnatal mammalian cardiomyogenesis and touch upon therapeutic strategies that could potentially amplify innate cardiac regeneration.
  
  
  CONCLUSIONS
  The adult mammalian heart harbors a limited but detectable capacity for spontaneous endogenous regeneration. During normal aging, proliferation of pre-existing cardiomyocytes is the dominant mechanism for generation of new cardiomyocytes. Following myocardial injury, myocyte proliferation increases modestly, but differentiation of endogenous progenitor cells appears to also contribute to cardiomyogenesis (although agreement on the latter point is not universal). Since cardiomyocyte deficiency underlies almost all types of heart disease, development of therapeutic strategies that amplify endogenous regeneration to a clinically-meaningful degree is of utmost importance.
authors.affiliation: a 3rd Department of Cardiology , University of Athens School of Medicine , Athens , Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Malliaras
authors.affiliation: a 3rd Department of Cardiology , University of Athens School of Medicine , Athens , Greece.
authors.forename: Styliani
authors.initials: S
authors.lastname: Vakrou
authors.affiliation: a 3rd Department of Cardiology , University of Athens School of Medicine , Athens , Greece.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Kapelios
authors.affiliation: a 3rd Department of Cardiology , University of Athens School of Medicine , Athens , Greece.
authors.forename: John N
authors.initials: JN
authors.lastname: Nanas
keywords: Cardiac regeneration; cardiac stem cells; myocyte proliferation; myocyte turnover