Comparison of enzymatic and nonenzymatic isolation methods for endometrial stem cells

Abstract

Human endometrial stem cells (hESCs) are mesenchymal stem cells, which are responsible for the monthly renewal of the basal layer of the human endometrium by facilitating stromal and vascular regeneration. In this study, hESCs were isolated by using three different isolation methods including nonenzymatic and enzymatic digestion with trypsin and collagenase type 1. To determine the efficiency of these three methods, cells were characterized using a cell proliferation assay and mesenchymal and hematopoietic stem cell markers. Our results demonstrate that although the nonenzymatic isolation method gave rise to hESCs that had a higher proliferative rate, the mesenchymal stem cell profiles for hESCs isolated with three methods were similar, with no significant difference for the early passages. However, late passage hESCs isolated using trypsin showed a CD31highCD44low profile. Similarly, when hESCs isolated with the nonenzymatic method were kept until late passage, they demonstrated a CD31high profile with a significant decrease in CD90, CD73, CD44, and CD105 surface expression levels. Only hESCs isolated with collagenase type 1 did not present a significant shift in their mesenchymal CD marker profile from early to late passages, suggesting that the long-term maintenance of mesenchymal markers could only be achieved in cell isolation with collagenase type 1.