Mouse dental pulp stem cells support human umbilical cord blood-derived hematopoietic stem/progenitor cells in vitro.

It is well documented that specialized mesenchymal stem/stromal cells (MSCs) constitute the hematopoietic stem cell (HSC) niche in the bone marrow (BM), and these MSCs support/maintain the HSCs in an undifferentiated state. A number of studies have demonstrated that BM-derived MSCs (BM-MSCs) can support HSCs in vitro. However, it remains unclear whether nonhematopoietic tissue-derived MSC-like cells, such as dental pulp stem cells (DPSCs), have the ability to support HSCs. In this study, we prospectively isolated DPSCs from mouse mandibular incisors by fluorescence-activated cell sorting (FACS) using BM-MSC markers, such as PDGFRα and Sca-1. The PDGFRα and Sca-1 double-positive DPSCs and BM-MSCs showed similar morphologies and expression patterns of MSC markers. The ability of the DPSCs to support hematopoietic stem/progenitor cells (HSPCs) was then analyzed by an in vitro coculture system. Moreover, their HSC-supporting activity was evaluated by in vivo xenotransplantation assays using NOD/Shi-scid/IL-2R...