Characterization of Mesenchymal Stem Cells Isolated from Mouse Fetal Bone Marrow

Xiaoli Wang^a^,e, Hiroko Hisha^a^,b^,c, Shigeru Taketani^d, Yasushi Adachi^a^,b, Qiang Li^a, Wenhao Cui^a, Yunze Cui^a, Jianfeng Wang^a, Changye Song^a, Tomomi Mizokami^a, Satoshi Okazaki^a, Qing Li^a, Tianxue Fan^a, Hongxue Fan^e, Zhexiong Lian^f, M. Eric Gershwin^f, Susumu Ikehara^a^,b^,c

^a First Department of Pathology,
^b Regeneration Research Center for Intractable Diseases,
^c Department of Transplantation for Regeneration Therapy, Kansai Medical University, Moriguchi City, Osaka, Japan;
^d Department of Biotechnology, Kyoto Institute of Technology, Kyoto, Japan;
^e Department of Toxicology, School of Public Health, Jilin University, Changchun, China;
^f Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, California, USA

Key Words. Mesenchymal stem cells • Hematopoietic stem cells • Bone marrow cells • PA6 • Mouse

Correspondence: Susumu Ikehara, M.D., Ph.D., First Department of Pathology, Kansai Medical University, 10-15 Fumizono-cho, Moriguchi City, Osaka 570-8506, Japan. Telephone: +81-6-6993-9429; Fax: +81-6-6994-8283; e-mail: ikehara{at}takii.kmu.ac.jp.

Received May 16, 2005; accepted for publication August 30, 2005.
Mesenchymal stem cells (MSCs) are defined as cells that candifferentiate into multiple mesenchymal lineage cells. MSCshave some features (surface molecules and cytokine production,etc.) common to so-called traditional bone marrow (BM) stromalcells, which have the capacity to support hemopoiesis. In thepresent study, we isolated murine MSCs (mMSCs) from the fetalBM using an anti-PA6 monoclonal antibody (mAb) that is specificfor bone marrow stromal cells. The mMSCs, called FMS/PA6-P cells,are adherent, fibroblastic, and extensively expanded and havethe ability to differentiate not only into osteoblasts and adipocytesbut also into vascular endothelial cells. The FMS/PA6-P cellsproduce a broad spectrum of cytokines and growth factors closelyrelated to hemopoiesis and show good hemopoiesis-supportingcapacity both in vivo and in vitro, suggesting that they area component of the hemopoietic stem cell niche in vivo. Interestingly,although the FMS/PA6-P cells express a high level of the PA6molecule, which is reactive with anti-PA6 mAb, they graduallylose their ability to express this molecule during the courseof differentiation into osteoblasts and adipocytes, indicatingthat the PA6 molecule might serve as a novel marker of mMSCs.