Department of Cell Biology, Institute of Basic Medical Sciences, Beijing 100850, China.
J Genet Genomics. 2010 Jul;37(7):475-82. doi: 10.1016/S1673-8527(09)60067-9.
Mesenchymal stem cells (MSCs) are multipotent stem cells capable of differentiating into various cell types, including osteocytes, chondrocytes, adipocytes, myocytes, and tenocytes. However, the difficulty or failure in expanding the mouse MSCs in vitro greatly hampered important research in animal models. The OP9, a stromal cell line from mouse bone marrow, has hematopoietic supportive capacity. Here, we report that the OP9 has the immunophenotype (CD45(-), CD11b(-), FLK-1(-), CD31(-), CD34(-), CD44(+), CD29(+), Sca-1(+), CD86(-), and MHCII(-)) identical to canonical mouse MSCs. The expression of CD140a(+), CD140b(+), alpha-SMA(+) and Calponin(+) suggested the perivascular origin of OP9. Functionally, the OP9 had strong clonogenic ability and could be induced into osteocytes, chondrocytes and adipocytes. The lymphocyte transformation test (LTT) and mixed leukocyte reaction (MLR) showed that the OP9 could suppress T lymphocyte proliferation stimulated by nonspecific mitogens (PHA) or allogeneic lymphocytes (BALB/c T cells). Finally, the migration of OP9 could be efficiently induced by bFGF, IGF-1, IL-3, PDGF-BB, TGF-beta1 and TGF-beta3. In conclusion, the OP9 were bona fide MSCs, and such homogenous cell line will be helpful to delineate biological features of MSCs at the stem cell level.
间充质干细胞（MSCs）是多能干细胞，能够分化为多种细胞类型，包括成骨细胞、软骨细胞、脂肪细胞、肌细胞和成纤维细胞。然而，在体外扩增小鼠 MSCs 的困难或失败极大地阻碍了动物模型的重要研究。OP9 是一种来自小鼠骨髓的基质细胞系，具有造血支持能力。在这里，我们报告 OP9 具有与经典小鼠 MSCs 相同的免疫表型（CD45(-)，CD11b(-)，FLK-1(-)，CD31(-)，CD34(-)，CD44(+)，CD29(+)，Sca-1(+)，CD86(-)和 MHCII(-)）。CD140a(+)、CD140b(+)、alpha-SMA(+)和 Calponin(+)的表达提示 OP9 来源于血管周围。功能上，OP9 具有很强的集落形成能力，并可诱导分化为成骨细胞、软骨细胞和脂肪细胞。淋巴细胞转化试验（LTT）和混合淋巴细胞反应（MLR）表明，OP9 可抑制非特异性有丝分裂原（PHA）或同种异体淋巴细胞（BALB/c T 细胞）刺激的 T 淋巴细胞增殖。最后，OP9 的迁移可以被 bFGF、IGF-1、IL-3、PDGF-BB、TGF-beta1 和 TGF-beta3 有效地诱导。总之，OP9 是真正的 MSCs，这种同质细胞系将有助于在干细胞水平上描绘 MSCs 的生物学特征。
