There is evidence that mesenchymal stem cells (MSC) can contribute tot bone marrow (BM) stroma and hematopoietic recovery after hematopoietic stem cell transplantation.
Since MSC can form osteocytes, there is also interest to use MSC for bone repair in patients with inborn or aquired defects. For these clinical applications it is important that MSC home to BM sites after in vitro expansion and systemic infusion. Previously we demonstrated that BM-derived MSC expanded at low density migrate better through BM endothelium as compared to MSC cultured at high density (De Becker et al). More recently we could confirm these data in an in vivo model (111In labeled human MSC in NOD/SCID mice). In this study we analyzed expression of the chemokinereceptors and BM-derived cytokine receptors by human BM-derived MSC and their functional involvement in the in vitro transendothelial migration (TEM) of MSC. With TEM toward 10% BM plasma stimulation of MSC homing by BM-derived molecules was assessed and showed significant increase of migration to BM plasma as compared to RPMI. Next, we investigated the expression of several receptors involved in BM homing and/or bone metastasis. In first instance multiplex RT-PCR showed mRNA transcripts for CCR-1, CCR-5, CCR-7 and CCR-9 in MSC but no membranar or cytoplasmic expression could be found.
We also examined the expression of cytokinereceptors involved in BM homing or bone metastasis. We found mRNA transcripts for c-met, PDGFRa, PDGFRb, IL-6R. With FACS strong expression of PDGFRa & b was found, while surface expression of c-met en IL-6R could not be demonstrated. TEM shows that MSC migrate significantly better to PDGF-BB than RPMI in vitro. After PDGFRa & b knockdown there was a partial inhibition of MSC migration to BMplasma. In conclusion we can state that MSC express a poor phenotype of receptors for BM chemotactic molecules but there is evidence that PDGFRa & b actively contribute to the BM homing of MSC.
Original languageEnglish
Title of host publication25th General Meeting of the Belgian Hematological Society - Abstract Posters Stem Cell Biology and Transplantation p. 99
PublisherBelgian Hematological Society
Publication statusPublished - 29 Jan 2010

    Research areas

  • bone marrow stroma, transendothelial migration, mesenchymal stem cell, homing

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