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探讨力学因素对大鼠骨髓间充质干细胞(MSCs)中基质金属蛋白酶-9(MMP-9)基因表达的影响及可能的信号机制。体外分离培养大鼠骨髓MSCs;利用平行平板流动腔力学加载装置,对细胞进行低(5 dyne/cm2)、中(15dyne/cm2)和高(30 dyne/cm2)不同剪应力的刺激,采用RT-PCR技术分析MMP-9基因的表达;利用Wortmannin(PI3K特异性抑制剂)、SB202190(P38MAPK特异性抑制剂)和PD98059(ERK1/2MAPK特异性抑制剂)信号阻断剂探讨力学信号传导途径。结果显示:(1)MSCs在未受力状态下MMP-9基因的表达较弱,15 dyne/cm2剪应力作用2 h表达即明显增强,24 h达高峰,呈时间依赖;(2)低、中和高剪应力分别刺激2 h,均可使MSCs MMP-9基因表达增强,其中15 dyne/cm2时最强;(3)用三种信号通路的抑制剂预处理后,SB202190组MMP-9基因表达明显被抑制。以上结果表明:剪应力可诱导MSCs中MMP-9基因表达,其表达量与刺激时间和剪应力的强度密切相关,其中p38MAPK信号通路起关键作用。
To investigate the effect of mechanics on the expression of matrix metalloproteinase-9 (MMP-9) gene in rat bone marrow mesenchymal stem cells (MSCs) and its possible signal mechanism. The bone marrow MSCs were isolated and cultured in vitro. The cells were stimulated with low shear stress (5 dyne / cm2), medium (15 dyne / cm2) and high shear stress (30 dyne / cm2) The expression of MMP-9 gene was analyzed by PCR. The mechanistic signal transduction pathways were investigated by using Wortmannin (PI3K specific inhibitor), SB202190 (P38MAPK specific inhibitor) and PD98059 (ERK1 / 2MAPK specific inhibitor) signal blocker. The results showed that: (1) The expression of MMP-9 gene in MSCs under stress was weak, and the expression of MMP-9 at 15 dyne / cm2 was significantly increased at 2 h and reached a peak at 24 h, which was time dependent; (2) After stimulation with neutralizing high shear stress for 2 h, MMP-9 gene expression was enhanced in MSCs, of which 15 dyne / cm2 was the strongest. (3) After pretreated with three signaling inhibitors, MMP-9 Gene expression was significantly inhibited. The above results show that: Shear stress can induce MMP-9 gene expression in MSCs, the expression of which is closely related to the stimulation time and the intensity of shear stress, of which p38MAPK signaling pathway plays a key role.