Division of Stem Cell and Tissue Engineering, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, PR China.
J Cell Biochem. 2012 Apr;113(4):1407-15. doi: 10.1002/jcb.24014.
Bone marrow-derived mesenchymal stem cells (BM-MSCs) are the popular seed cells for regenerative medicine, and there has been a rapid increase in the number of BM-MSC-based clinical trials. However, the safety of these cells should also be closely studied. In this study, spontaneous calcification of BM-MSCs from rats was evaluated in normoxia (20% O(2)) without osteogenic medium after continuous culture for 21 days; obvious mineralized nodules were observed, which were positive for Alizarin Red, collagen-I (Col-I), osteocalcin (OC) and alkaline phosphatase (ALP), and mainly consisted of C, O and Ca elements. Interestingly, hypoxia (2% O(2)) significantly inhibited this spontaneous calcification. In addition, the ALP and calcium content of rBM-MSCs were sharply reduced. Based on RT-PCR results, the expression of osteogenic genes (Cbfa1/Runx2, Col-I, ALP, and OC) was reduced compared to that in normoxia. These results demonstrate a natural and unique characterization of rat BM-MSCs in normoxia after continuous culture and highlight the inhibiting effects of hypoxia. Finally, this study contributes to the information regarding the application of BM-MSCs in the regeneration of various tissues.
骨髓间充质干细胞（BM-MSCs）是再生医学中常用的种子细胞，基于 BM-MSC 的临床试验数量迅速增加。然而，这些细胞的安全性也应密切研究。在这项研究中，在无成骨培养基的常氧（20% O(2)）条件下，连续培养 21 天后，评估大鼠 BM-MSCs 的自发性钙化；观察到明显的矿化结节，茜素红、Ⅰ型胶原（Col-I）、骨钙素（OC）和碱性磷酸酶（ALP）染色均为阳性，主要由 C、O 和 Ca 元素组成。有趣的是，低氧（2% O(2)）显著抑制了这种自发性钙化。此外，rBM-MSCs 的 ALP 和钙含量急剧减少。基于 RT-PCR 结果，与常氧相比，成骨基因（Cbfa1/Runx2、Col-I、ALP 和 OC）的表达减少。这些结果表明大鼠 BM-MSCs 在连续培养后的常氧条件下具有自然而独特的特征，并强调了低氧的抑制作用。最后，这项研究为 BM-MSC 在各种组织再生中的应用提供了信息。
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