IFATS Collection: Stem Cell Antigen-1-Positive Ear Mesenchymal Stem Cells Display Enhanced Adipogenic Potential
Article first published online: 3 JUL 2008
Copyright © 2008 AlphaMed Press
Volume 26, Issue 10, pages 2666–2673, October 2008
How to Cite
Staszkiewicz, J., Gimble, J. M., Manuel, J. A. and Gawronska-Kozak, B. (2008), IFATS Collection: Stem Cell Antigen-1-Positive Ear Mesenchymal Stem Cells Display Enhanced Adipogenic Potential. STEM CELLS, 26: 2666–2673. doi: 10.1634/stemcells.2008-0270
- Issue published online: 9 JAN 2009
- Article first published online: 3 JUL 2008
- Manuscript Accepted: 20 JUN 2008
- Manuscript Received: 19 MAR 2008
- Stem cell antigen 1;
- Mesenchymal stem cells;
Hyperplasia is a major contributor to the increase in adipose tissue mass that is characteristic of obesity. However, the identity and characteristics of cells that can be committed into adipocyte lineage remain unclear. Stem cell antigen 1 (Sca-1) has been used recently as a candidate marker in the search for tissue-resident stem cells. In our quest for biomarkers of cells that can become adipocytes, we analyzed ear mesenchymal stem cells (EMSC), which can differentiate into adipocytes, osteocytes, chondrocytes, and myocytes. Our previous studies have demonstrated that EMSC abundantly expressed Sca-1. In the present study, we have analyzed the expression of adipogenic transcription factors and adipocyte-specific genes in Sca-1-enriched and Sca-1-depleted EMSC fractions. Sca-1-enriched EMSC accumulated more lipid droplets during adipogenic differentiation than Sca-1-depleted. Similarly, EMSC isolated from Sca-1−/− mice displayed reduced lipid accumulation relative to EMSC from wild-type controls (p < .01). Comparative analysis of the adipogenic differentiation process between Sca-1-enriched and Sca-1-depleted populations of EMSC revealed substantial differences in the gene expression. Preadipocyte factor 1, CCAAT enhancer-binding protein (C/EBP) β, C/EBPα, peroxisome proliferator-activated receptor γ2, lipoprotein lipase, and adipocyte fatty acid binding protein were expressed at significantly higher levels in the Sca-1-enriched EMSC fraction. However, the most striking observation was that leptin was detected only in the conditioned medium of Sca-1-enriched EMSC. In addition, we performed loss-of-function (Sca-1 morpholino oligonucleotide) experiments. The data presented here suggest that Sca-1 is a biomarker for EMSC with the potential to become functionally active adipocytes.
Disclosure of potential conflicts of interest is found at the end of this article.