Haematopoietic stem cells improve cardiac function after infarction without permanent cardiac engraftment.
BACKGROUND
Transplantation of bone marrow derived adult stem cells (BMC) improves cardiac function after acute myocardial infarction (MI). However, the cell population mediating myocardial recovery and the fate of the transplanted cells are still controversial.


OBJECTIVE
We determined the effects of Sca-1+ c-kit+ lin- haematopoietic BMC on cardiac function after MI and the cell fate after transplantation.


METHODS
Sca-1+ c-kit+ lin- BMC of male donor C57BL/6 mice were transplanted by intravenous injection into syngenic females after permanent MI. LV dimensions and function were determined by echocardiography and cardiac magnetic resonance imaging, transplanted BMC were identified by Y chromosome DNA in situ hybridization.


RESULTS
BMC treatment completely prevented LV dilation (LV end-diastolic volume BMC 70 +/- 16 microl vs. control 122 +/- 41 microl; p < 0.05) and improved fractional shortening (BMC 22.9 +/- 8% vs. control 15.4 +/- 8.4%; p < 0.05) and ejection fraction BMC 68.2 +/- 6.6% vs. control 52 +/- 14.3%; p < 0.05) as early as 3 days after transplantation, but did not decrease infarct size (BMC 27 +/- 6% vs. control 28 +/- 7%, p = n.s.). After 4 weeks, only sporadic cells of male origin were identified in infarcted hearts (< 0.01% of periinfarct cells).


CONCLUSIONS
Intravenous injection of Sca-1+ c-kit+ lin- in BMC after MI improves LV dimensions and function without evidence for long term engraftment.
Limbourg
Florian P
FP
Department of Cardiology and Angiology, Medizinische Hochschule Hannover, Germany. limbourg.florian@mh-hannover.de
Ringes-Lichtenberg
Stefanie
S
Schaefer
Arnd
A
Jacoby
Christoph
C
Mehraein
Yasmin
Y
Jäger
Mark D
MD
Limbourg
Anne
A
Fuchs
Martin
M
Klein
Gunnar
G
Ballmaier
Matthias
M
Schlitt
Hans-J
HJ
Schrader
Juergen
J
Hilfiker-Kleiner
Denise
D
Drexler
Helmut
H
D000818:Animals; D000950:Antigens, Ly; D004108:Dilatation, Pathologic; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells; D017403:In Situ Hybridization; D008279:Magnetic Resonance Imaging; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D009203:Myocardial Infarction / Q000601:surgery*; D016277:Ventricular Function, Left
D000950:Antigens, Ly; C074650:Ly6a protein, mouse; D008565:Membrane Proteins