Stem cells offer the hope of curing a variety of ailments such as diabetes, Parkinsons disease, myocardial infarct, muscular dystrophy and spinal cord injuries. In this regard, a detailed understanding of the origin and behavior of stem cells is invaluable to the advancement of public health. The adult human adipose tissue (hWAT) is an attractive and convenient source of therapeutic cells for use in the clinical setting. Previous studies have demonstrated that the stromal vascular compartment within hWAT contains multipotent cells, called adipose stem cells (ASC). However, the identity and anatomic distribution of ASC or progenitors within hWAT remain unclear. We addressed this issue through an a priori identification of different cell subsets within the hWAT stroma, by visualization of cells in their native state within the resident tissue, and analysis of their immunohistochemical profile. Endothelial cells, pericytes, as well as non-vascular cells from adult subcutaneous abdominal fat were separated and sorted to homogeneity based on CD34, CD146 and CD45 antigen expression. We first tested the adipogenic potential of the different purified stromal cell populations. A higher level of leptin mRNA, as much as a 20-fold difference, was observed in pericytes and the non-vascular cell fractions when compared to endothelial cells. High levels of leptin expression were maintained even after extensive expansion of the cells in culture. Additionally, we found
a reserve of brown adipocyte progenitors within the adult fat tissue vasculature, among pericytes, which challenges the notion that uncoupling protein-1 (UCP-1) expressing cells are confined to fetal and early human life. We also herein describe a precedently unsuspected role of adipose-derived pericytes as human muscle progenitors. When transplanted into cardiotoxin-injured NOD-SCID mouse muscles, pericytes generated a significantly higher number of myofibers than the other hWAT stromal cell populations. Quantitatively, the myogenic potential of adipose-derived pericytes was similar to that of a population of robustly myogenic cells within the skeletal muscle of adult humans, the myogenic-endothelial cells. The long-term culture of hWAT pericytes did not diminish their capacity for myogenic differentiation. These results suggest that human adipose tissue is a viable alternative tissue source to skeletal muscle for muscle cell-mediated therapy.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-08032006-193839 |
| Date | 09 October 2006 |
| Creators | Yap, Solomon Veloso |
| Contributors | Kacey Marra, PhD, Johnny Huard, PhD, Bruno Peault, PhD, Robert Ferrell, PhD |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-08032006-193839/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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