通过控制连续超声波的频率可加速人脂肪来源干细胞的成骨分化。

Osteogenic differentiation of human adipose-derived stem cells can be accelerated by controlling the frequency of continuous ultrasound.

机构信息

Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Korea.

出版信息

J Ultrasound Med. 2013 Aug;32(8):1461-70. doi: 10.7863/ultra.32.8.1461.

DOI:10.7863/ultra.32.8.1461

PMID:23887957

Abstract

OBJECTIVES

The purpose of this study was to demonstrate that the effects of continuous ultrasound on the osteogenic differentiation of human adipose-derived stem cells (hASCs) are dependent on the frequency in vitro.

METHODS

Before stimulation, we characterized the hASCs using cluster of differentiation marker profiles and tridifferentiation. Then we selected effective frequencies in the range of 0.5 to 1.5 MHz (with a peak negative pressure of 52 kPa), which upregulated runt-related transcription factor 2 messenger RNA expression. Next, the effects of ultrasound at the selected frequencies on the osteogenic differentiation were evaluated at the protein level. Alkaline phosphatase activity and the formation of mineralized nodules were measured. We additionally identified the cellular mechanisms underlying the effects of ultrasound stimulation using Western blotting.

RESULTS

The hASCs showed general cluster of differentiation marker profiles of stem cells and confirmed their potentials to yield adipogenic, chondrogenic, and osteogenic differentiation. Frequencies of 0.5, 1.0, and 1.5 MHz were selected for higher runt-related transcription factor 2 expression in the range of 0.5 to 1.5 MHz. Among the 3 groups, alkaline phosphatase activity and the formation of mineralized nodules were increased in cells exposed to 1.5-MHz ultrasound compared with cells exposed to 0.5-or 1.0-MHz ultrasound and nontreated control cells. We additionally confirmed that this acceleration of osteogenic differentiation was related to p38 and protein kinase B signaling pathways.

CONCLUSIONS

In this study, we found that, in the selected range, 1.5 MHz was the most effective frequency for inducing the osteogenic differentiation of hASCs.

摘要

目的

本研究旨在证明体外连续超声对人脂肪源性干细胞（hASC）成骨分化的影响取决于频率。

方法

刺激前，我们使用分化标志物谱和三分化对 hASC 进行特征描述，然后选择有效频率范围为 0.5 至 1.5MHz（峰负压为 52kPa），可上调 runt 相关转录因子 2 信使 RNA 表达。接下来，在蛋白质水平评估选定频率的超声对成骨分化的影响。测量碱性磷酸酶活性和矿化结节的形成。我们还使用 Western blot 鉴定了超声刺激作用的细胞机制。

结果

hASC 显示出干细胞的一般分化标志物谱，并证实了它们具有产生脂肪、软骨和成骨分化的潜力。在 0.5 至 1.5MHz 的范围内选择 0.5、1.0 和 1.5MHz 的频率以获得更高的 runt 相关转录因子 2 表达。在 3 组中，与接受 0.5 或 1.0MHz 超声和未处理对照细胞的细胞相比，接受 1.5MHz 超声的细胞中碱性磷酸酶活性和矿化结节的形成增加。我们还证实，这种成骨分化的加速与 p38 和蛋白激酶 B 信号通路有关。