Tabuchi Yoshiaki, Hasegawa Hideyuki, Suzuki Nobuo, Furusawa Yukihiro, Hirano Tetsushi, Nagaoka Ryo, Takeuchi Shin-Ichi, Shiiba Michihisa, Mochizuki Takashi
Division of Molecular Genetics Research, Life Science Research Center, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
Graduate School of Innovative Life Science, University of Toyama, Toyama, Japan.
J Med Ultrason (2001). 2020 Apr;47(2):193-201. doi: 10.1007/s10396-020-01007-9. Epub 2020 Feb 5.
The effects of low-intensity pulsed ultrasound (LIPUS) on the expression of immediate-early genes (IEGs) in bone marrow stromal cells (BMSCs) were evaluated to elucidate the early cellular response to LIPUS.
Mouse ST2 BMSCs were treated with LIPUS (I, 12-34 mW/cm for 20 min), then cultured at 37 °C. The expression levels of four IEGs (Fos, Egr1, Jun, and Ptgs2) and ERK1/2, a mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), were assessed using real-time quantitative PCR and Western blot analyses, respectively.
A single exposure of LIPUS at an intensity of 25 mW/cm significantly and transiently increased the expression levels of all four IEGs, and the peak expression was detected at 30-60 min after LIPUS stimulation. LIPUS exposure also significantly increased the phosphorylation level of ERK1/2. U0126, an inhibitor of MAPK/ERK, significantly prevented LIPUS-induced expression of Fos and Egr1, but not that of Jun and Ptgs2. On the other hand, treatment of the cells with LIPUS did not affect cell growth or alkaline phosphatase activity, a marker of osteoblast differentiation.
These results suggest that LIPUS exposure significantly induces expression of IEGs such as Fos and Egr1 via the MAPK/ERK pathway in ST2 BMSCs.
评估低强度脉冲超声（LIPUS）对骨髓基质细胞（BMSCs）中即刻早期基因（IEGs）表达的影响，以阐明细胞对LIPUS的早期反应。
用LIPUS（I，12 - 34 mW/cm，持续20分钟）处理小鼠ST2 BMSCs，然后在37°C下培养。分别使用实时定量PCR和蛋白质免疫印迹分析评估四种IEGs（Fos、Egr1、Jun和Ptgs2）以及丝裂原活化蛋白激酶/细胞外信号调节激酶（MAPK/ERK）之一的ERK1/2的表达水平。
单次暴露于强度为25 mW/cm的LIPUS可显著且短暂地增加所有四种IEGs的表达水平，在LIPUS刺激后30 - 60分钟检测到表达峰值。LIPUS暴露还显著增加了ERK1/2的磷酸化水平。MAPK/ERK抑制剂U0126可显著抑制LIPUS诱导的Fos和Egr1的表达，但不影响Jun和Ptgs2的表达。另一方面，用LIPUS处理细胞不影响细胞生长或碱性磷酸酶活性（成骨细胞分化的标志物）。
这些结果表明，LIPUS暴露可通过MAPK/ERK途径在ST2 BMSCs中显著诱导Fos和Egr1等IEGs的表达。
