Human cord blood progenitors with high aldehyde dehydrogenase activity improve vascular density in a model of acute myocardial infarction.
Human stem cells from adult sources have been shown to contribute to the regeneration of muscle, liver, heart, and vasculature. The mechanisms by which this is accomplished are, however, still not well understood. We tested the engraftment and regenerative potential of human umbilical cord blood-derived ALDH(hi)Lin(-), and ALDH(lo)Lin(-) cells following transplantation to NOD/SCID or NOD/SCID beta2m null mice with experimentally induced acute myocardial infarction. We used combined nanoparticle labeling and whole organ fluorescent imaging to detect human cells in multiple organs 48 hours post transplantation. Engraftment and regenerative effects of cell treatment were assessed four weeks post transplantation. We found that ALDH(hi)Lin(-) stem cells specifically located to the site of injury 48 hours post transplantation and engrafted the infarcted heart at higher frequencies than ALDH(lo)Lin(-) committed progenitor cells four weeks post transplantation. We found no donor derived cardiomyocytes and few endothelial cells of donor origin. Cell treatment was not associated with any detectable functional improvement at the four week endpoint. There was, however, a significant increase in vascular density in the central infarct zone of ALDH(hi)Lin(-) cell-treated mice, as compared to PBS and ALDH(lo)Lin(-) cell-treated mice.


CONCLUSIONS
Our data indicate that adult human stem cells do not become a significant part of the regenerating tissue, but rapidly home to and persist only temporarily at the site of hypoxic injury to exert trophic effects on tissue repair thereby enhancing vascular recovery.
Sondergaard
Claus S
CS
Department of Molecular Biology, Department of Hematology and Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Hess
David A
DA
Maxwell
Dustin J
DJ
Weinheimer
Carla
C
Rosová
Ivana
I
Creer
Michael H
MH
Piwnica-Worms
David
D
Kovacs
Attila
A
Pedersen
Lene
L
Nolta
Jan A
JA
D053687:Adult Stem Cells / Q000201:enzymology*; D000444:Aldehyde Dehydrogenase / Q000378:metabolism*; D000818:Animals; D019070:Cell Lineage; D002469:Cell Separation; D005312:Fetal Blood / Q000166:cytology / Q000201:enzymology; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009203:Myocardial Infarction / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology*; D012038:Regeneration / Q000502:physiology; D033581:Stem Cell Transplantation
D000444:Aldehyde Dehydrogenase