Putative mesenchymal stem cells isolated from adult human ovaries.

The purpose of this study was to show that healthy adult human ovaries can be a source of cells showing typical MSCs characteristics under in vitro conditions. The cells, which were isolated from ovarian cortex tissue and named putative ovarian mesenchymal stem cells (PO-MSCs), were compared to bone marrow-derived MSCs (BM-MSCs) and to adult human dermal fibroblasts (HDFs). The results of a gene expression analysis using the Human Mesenchymal Stem Cell RT² Profiler™ PCR Array revealed that PO-MSCs were different than fibroblasts. They expressed most of the analyzed genes as BM-MSCs, although some genes were differentially expressed. However, the heterogeneity of PO-MSCs samples was revealed. The PO-MSCs expressed the characteristic genes related to MSCs, such as CD105, CD44, CD90, M-CAM, CD73 and VCAM1. In addition, the expression of markers CD44, CD90, M-CAM and STRO-1 was confirmed in PO-MSCs using immunocytochemistry. The PO-MSCs showed multipotent character, since they were able to differentiate into the cells of adipogenic, osteogenic, neural and pancreatic lineage. Healthy adult human ovaries can harbour an interesting population of cells showing typical MSCs characteristics under in vitro conditions and for this reason we named these cells putative MSCs. These cells express genes encoding main MSCs markers and have an interesting differential potential. Based on these results, we propose PO-MSCs as a novel type of MSCs which share some similarities with BM-MSCs. Nevertheless they show distinct and specific characteristics and are not fibroblasts.