单克隆和不同接种密度人永生化骨髓基质细胞体内外分化差异性的研究

Effect of monoclonal or different cell seeding densities on the differentiation potential of immortalized hmnan mesenchymal stem cells in vitro and in vivo

目的研究单克隆和接种密度对永生化骨髓基质干细胞（hMSC—TERT）体内、外分化潜能的影响，寻找合理的体外培养模式。方法从亲代hMSC—TERT中，建立了30个单克隆细胞系，并以不同的接种密度建立了2个独立的细胞系。对各细胞系在体外向脂肪、骨、神经样细胞方向诱导分化，用免疫组化的方法测定细胞在SCID鼠体内的多向分化潜能。结果高接种密度细胞比单克隆和低接种密度细胞拥有更多的体外分化潜能，更好的保持了基质细胞特性。各单克隆细胞体内分化能力存在差异，甚至可以具有亲代细胞没有的分化能力。结论以高接种密度的方式培养多克隆原代细胞，能够保持细胞的原有特性。移植前，筛选特定的单克隆细胞，进行特定用途的移植。

Objective To determine whether monoclonality or different cell seeding densities could influence the differentiation potential of immortalized human mesenchymal stem cells （hMSC-TERT） and to find an effective cultural method of hMSC-TERT in vitro. Methods From the parental hMSC-TERT cell line, we derived 30 monoclonal cell lines and two independent cell lines based on different plating densities during expansion in culture. Their adipocytic, osteogenic, neuronal differentiation potential in vitro and multidirectional differentiation potential in vivo were analyzed by immunohistochemistry for pathologic tissue markers. Results Monoclonal cell lines and the cell line derived at low seeding density had a lower differentiation potential in vitro than the cell line derived at higher cell seeding density. The differentiation potential of monoclonal hMSC-TERT cells were dissimilar. Some of monoclonal hMSC-TERT lines expressed epithelial differentiation potential in vivo while the parental hMSC-TERT cells line did not. Conclusion Multiclonal hMSC-TERT ceils cultured in high seeding density can keep the differentiation potential, cloning the hMSC- TERT cells before transplantation to find the special clones for special purpose of transplantation.