Published online before print December 12, 2008
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Divisions of Clinical Pharmacology and Rheumatology, Department of Medicine, New York University School of Medicine, New York, New York, USA
1 Correspondence: Department of Medicine, New York University School of Medicine, 550 First Ave., New York, NY 10016, USA. E-mail: cronsb01{at}med.nyu.edu
ABSTRACT
Bone marrow-derived mesenchymal stem cells (BM-MSCs) play a role in wound healing and tissue repair and may also be useful for organ regeneration. As we have demonstrated previously that A2A adenosine receptors (A2AR) promote tissue repair and wound healing by stimulating local repair mechanisms and enhancing accumulation of endothelial progenitor cells, we investigated whether A2AR activation modulates BM-MSC proliferation and differentiation. BM-MSCs were isolated and cultured from A2A-deficient and ecto-5'nucleotidase (CD73)-deficient female mice; the MSCs were identified and quantified by a CFU-fibroblast (CFU-F) assay. Procollagen 
2 type I expression was determined by Western blotting and immunocytochemistry. MSC-specific markers were examined in primary cells and third-passage cells by cytofluorography. PCR and real time-PCR were used to quantitate adenosine receptor and CD73 expression. There were significantly fewer CFU-Fs in cultures of BM-MSCs from A2AR knockout (KO) mice or BM-MSCs treated with the A2AR antagonist ZM241385, 1 µM. Similarly, there were significantly fewer procollagen 2 type I-positive MSCs in cultures from A2AR KO and antagonist-treated cultures as well. In late passage cells, there were significantly fewer MSCs from A2A KO mice expressing CD90, CD105, and procollagen type I (P<0.05 for all; n=3). These findings indicate that adenosine and adenosine A2AR play a critical role in promoting the proliferation and differentiation of mouse BM-MSCs.
Key Words: CD73 • CD105 • CD34
