First published online February 28, 2008
Stem Cells
Vol. 26 No.
5
May 2008, pp.
1325
-1336
doi:10.1634/stemcells.2007-1072; www.StemCells.com
© 2008 AlphaMed Press
TISSUE-SPECIFIC STEM CELLS |
Metabolic Flexibility Permits Mesenchymal Stem Cell Survival in an Ischemic Environment
Louise A. Mylottea,
Angela M. Duffya,
Mary Murphya,
Timothy O'Briena,b,
Afshin Samalia,b,
Frank Barrya,
Eva Szegezdia,c
aRegenerative Medicine Institute, National Centre of Biomedical Engineering Science, and
Departments of bMedicine and
cBiochemistry, National University of Ireland, Galway, Galway, Ireland
Key Words. Cardiac ischemia • Hypoxia • Glucose deprivation • Mesenchymal stem cells • Apoptosis • Metabolic pathways
Correspondence: Eva Szegezdi, Ph.D., Cell Stress and Apoptosis Research Group, Regenerative Medicine Institute (REMEDI), National Centre for Biomedical Engineering Science, National University of Ireland, Galway, University Road, Galway, Ireland. Telephone: 353-91-495037; Fax: 353-91-495547; e-mail: eva.szegezdi{at}nuigalway.ie
Received December 17, 2007;
accepted for publication February 21, 2008.
First published online in STEM CELLS EXPRESS February 28, 2008.
The application of mesenchymal stem cells (MSCs) for myocardial repair following ischemic injury is of strong interest, but current knowledge regarding the survival and retention of differentiation potency of stem cells under ischemic conditions is limited. The present study investigated the effects of ischemia and its components (hypoxia and glucose depletion) on MSC viability and multipotency. We demonstrate that MSCs have a profoundly greater capacity to survive under conditions of ischemia compared with cardiomyocytes, measured by detecting changes in cellular morphology, caspase activity and phosphatidylserine exposure. MSCs were also resistant to exposure to hypoxia (0.5% O2), as well as inhibition of mitochondrial respiration with 2,4-dinitrophenol for 72 hours, indicating that in the absence of oxygen, MSCs can survive using anaerobic ATP production. Glucose deprivation (glucose-free medium in combination with 2-deoxyglucose) induced rapid death of MSCs. Depletion of cellular ATP occurred at a lower rate during glucose deprivation than during ischemia, suggesting that glycolysis has specific prosurvival functions, independent of energy production in MSCs. After exposure to hypoxic or ischemic conditions, MSCs retained the ability to differentiate into chondrocytes and adipocytes and, more importantly, retained cardiomyogenic potency. These results suggest that MSCs are characterized by metabolic flexibility, which enables them to survive under conditions of ischemic stress and retain their multipotent phenotype. These results highlight the potential utility of MSCs in the treatment of ischemic disease.
Disclosure of potential conflicts of interest is found at the end of this article.

Copyright © 2008 by AlphaMed Press.