Abstract 244: Characterization Of Endogenous C-kit Positive Cells From Right Atrial Appendage Of Neonate And Adult Heart Patients
Background: Stem cell therapy provides novel regenerative strategy for congenital heart patients. We have previously identified two distinct subpopulations (c-kit+ cells and cardiosphere derived cells (hCDCs)) from right atrial appendage (RAA) of neonate and adult heart patients. We have characterized hCDCs from neonate and adult heart patients and found strong regenerative capacity in hCDC derived from neonatal hearts. The aim of this study is to characterize c-kit+ cells derived from neonate and adult heart patients.
Methods: C-kit+ cells were isolated and expanded from RAA heart samples, ranging in weight from 20 mg to 300 mgs of tissues using the standard protocol. The atrial tissue was minced and suspended in Ham’s F12 medium containing collagenase NB 6. After digestion, cells were plated in c-kit growing media. C-kit+ cells were isolated using MACS column with >90% homogeneity. Cells were characterized using FACS and immunofluorescence techniques.
Results: The characterization of c-kit+ cells showed that these cells were co-expressing nkx2.5, GATA4 and FLK1 and negative for CD45, Lin and tryptase. The growth potential of c-kit+ cells was determined by use of doubling times which was never greater than 36 hours, computed by use of linear regression of log2 value of cell number. We observed neonate derived c-kit+ cells have more (2x) proliferation capacity compared to adult derived c-kit+ cells. During subsequent passages, c-kit expression was lost more in adult derived c-kit+ cells when compared to neonate derived c-kit+ cells.
Conclusion: Neonate derived c-kit+ cells retain their stemness and have more proliferative capacity compared to adult derived c-kit+ cells. Based on our previous study and present data we believe that neonate derived c-kit+ cells may have higher regenerative capacity compared to adult derived c-kit+ cells.
- © 2013 by American Heart Association, Inc.