Lee Hyun Jung, Choi Byung Hyune, Min Byoung-Hyun, Park So Ra
Department of Molecular Science and Technology, Ajou University, Suwon, Korea.
Tissue Eng. 2007 May;13(5):1049-57. doi: 10.1089/ten.2006.0346.
Many studies have investigated optimal chondrogenic conditions, but only a few of them have addressed their effects on cell viability or the methods to enhance it. This study investigated the effect of low-intensity ultrasound (LIUS), a well-known chondrogenic inducer, on the viability of human mesenchymal stem cells (hMSCs) during chondrogenic differentiation in three-dimensional (3-D) alginate culture. The hMSCs/alginate layer was cultured in a chondrogenic defined medium and treated with transforming growth factor-beta1 (TGF-beta1) and/or LIUS for 2 weeks. Along with chondrogenic differentiation for 2 weeks, the 3-D alginate culture and TGF-beta1 treatment resulted in the decrease of cell viability, which appeared to be mediated by apoptosis. In contrast, co-treatment with LIUS clearly enhanced cell viability and inhibited apoptosis under the same conditions. The effect of LIUS on the apoptotic event was further demonstrated by changes in the expression of apoptosis/viability related genes of p53, bax, bcl-2, and PCNA. These results suggest that the LIUS treatment could be a valuable tool in cartilage tissue engineering using MSCs as it enhances cell viability and directs the chondrogenic differentiation process, its well-known activity.
许多研究都对最佳软骨生成条件进行了探究，但其中只有少数研究涉及这些条件对细胞活力的影响或提高细胞活力的方法。本研究在三维（3-D）海藻酸盐培养的软骨生成分化过程中，考察了一种著名的软骨生成诱导剂——低强度超声（LIUS）对人间充质干细胞（hMSCs）活力的影响。将hMSCs/海藻酸盐层在软骨生成限定培养基中培养，并用转化生长因子-β1（TGF-β1）和/或LIUS处理2周。在进行2周软骨生成分化的同时，3-D海藻酸盐培养和TGF-β1处理导致细胞活力下降，这似乎是由凋亡介导的。相比之下，在相同条件下，LIUS联合处理明显提高了细胞活力并抑制了凋亡。p53、bax、bcl-2和PCNA等凋亡/活力相关基因表达的变化进一步证明了LIUS对凋亡事件的影响。这些结果表明，LIUS处理可能是一种在使用间充质干细胞的软骨组织工程中有价值的工具，因为它能提高细胞活力并指导软骨生成分化过程，这是其众所周知的活性。
