Hematopoietic-mesenchymal signal regulates properties of mesenchymal stem cells

It is well known that the properties of hematopoietic stem cells (HSCs) such as their ability to self-renew, and multipotency are maintained through interactions with mesenchymal cells. Meanwhile, the identification of cells that are the key component of niche remains a subject of dispute. Mesenchymal stem cells (MSCs) are one of the niche component cells, MSCs are one of the niche component cells which provide stemness signal to HSCs, while it is also hypothesized that there is also a counterpart signal from hematopoiesistic cells to mesenchymeal cells, as HSCs also constitute core stem cells niche for MSCs. Although mesenchymal stem cells (MSCs) have also been studied intensively, the signals involved in the maintenance of their properties have not attracted much attentions. We used microarrays to detail the global programme of gene expression underlying HSC-MSC interaction and identified distinct classes of regulated genes during this process. MSCs were selected at cocultured with HSC for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain homogeneous populations of MSCs in order to increase the temporal resolution of expression profiles. To that end, we FACS-sorted MSCs according to transduce sufficient signals at day 6 in cocultured.