Abstract 3547: Characterization of Human Cardiac Progenitor Populations Derived From Young Congenital Heart Patients
Background: Characterization of resident cardiac progenitor cells (CPC) from children, for cell-based regenerative strategies in non-ischemic forms of congenital heart disease (CHD) is lacking. The easy surgical accessibility and structural redundancy of atrial myocardium render it an attractive source for progenitor cell isolation. We examined CPC resident in intact right atrium (RA) and progenitor cells isolated by the cardiosphere method.
Methods: RA specimens were obtained during routine congenital surgical procedures from patients in three age groups: Neonates (<30 days); infants (1 month to 2 years); and children (>2 years to ≤13 years). CPC in intact RA and cardiosphere derived cells (CDC) were analyzed across age groups.
Results: The expression of c-kit, Ki67, and Nkx2.5 in intact RA, as well as c-kit+Ki67+and c-kit+Nkx2.5+ co-expression, were all significantly higher in neonates than in infants or children above 2. Isolated CDC could be expanded, and those derived from neonates retained significantly higher c-kit expression. CDC expressed mesenchymal markers CD90 and CD105 and cardiac markers α-sarcomeric actin (α-actin), sarcoplasmic reticulum Ca2+ ATPase-2 (SERCA2), connexin 43 (CX43) and Nkx2.5 at late passages, and were hematopoietic lineage negative. No difference in the expression of any marker in resident CPC or in isolated CDC was observed between cyanotic and acyanotic patients.
Conclusions: This study identified a new source of abundant resident CPC within young human RA that maintain the highest progenitor character and proliferation during the neonatal period. Isolated CDC exhibited a mesenchymal phenotype and expressed cardiac specific markers. Cardiosphere-mediated progenitor cell isolation provides possibilities for CDC use in congenital cardiac repair.