Chen Longju, Sun Xiaodong, Tang Jie, Ding Yan, Li Jing, Li Wenchun, Gong Jian, Wang Hanqin
Department of Anatomy, Yunyang Medical College, Shiyan 442000, China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2010 Dec;27(6):1261-5.
This paper was designed to investigate the effect of laminar shear stress on matrix metalloproteinase -9 (MMP-9) expression in rat bone marrow-derived mesenchymal stem cells (MSCs), and the possible signal transduction mechanism involved. Rat bone marrow MSCs were isolated and cultured, then, exposed to laminar shear stress at indicated strengths such as low (5dyne/cm2), medium (15 dyne/cm2) and high (30 dyne/cm2) via parallel plate flow chamber. RT-PCR was used to analyze the expression of MMP-9. The signaling inhibitors such as Wortmannin (PI3K specific inhabitor), SB202190 (p38MAPK specific inhabitor), and PD98059 (ERK1/2 specific inhabitor) were used to investigate the possible mechanical signal transduction pathway. The results showed: (1) The expression of MMP-9 was weak in static state, however, MMP-9 expression increased when MSCs were exposed to 15 dyne/cm2 shear stress for 2 hours, and MMP-9 expression increased with the extension of stimulating time, and it reached the peak at 24 h; (2) MSCs were stimulated by shear stress for 2 hours at different strengths (5 dyne/cm2, 15 dyne/cm2, 30 dyne/cm2), and under all these conditions, the expression of MMP-9 increased, and reached the peak at 15 dyne/cm2; (3) After MSCs were pretreated by three kinds of signal pathway inhibitors, the expression of MMP-9 did not change obviously in Wortmannin group and PD98059 group, but it was significantly inhibited in SB202190 group. This study demonstrated that shear stress could induce the expression of MMP-9 in rat bone marrow-derived mesenchymal stem cells; the amount of MMP-9 expression was closely related to stimulating time and the strengths of shear stress; and p38MAPK signal pathway played a critical role during the process.
本文旨在研究层流切应力对大鼠骨髓间充质干细胞（MSCs）中基质金属蛋白酶-9（MMP-9）表达的影响及其可能涉及的信号转导机制。分离培养大鼠骨髓间充质干细胞，然后通过平行板流动腔使其暴露于低（5达因/平方厘米）、中（15达因/平方厘米）、高（30达因/平方厘米）等指定强度的层流切应力下。采用逆转录聚合酶链反应（RT-PCR）分析MMP-9的表达。使用渥曼青霉素（PI3K特异性抑制剂）、SB202190（p38丝裂原活化蛋白激酶特异性抑制剂）和PD98059（细胞外信号调节激酶1/2特异性抑制剂）等信号抑制剂来研究可能的机械信号转导途径。结果显示：（1）在静态状态下MMP-9表达较弱，然而，当间充质干细胞暴露于15达因/平方厘米切应力2小时时，MMP-9表达增加，且随着刺激时间的延长MMP-9表达增加，并在24小时达到峰值；（2）间充质干细胞在不同强度（5达因/平方厘米、15达因/平方厘米、30达因/平方厘米）下受切应力刺激2小时，在所有这些条件下，MMP-9表达均增加，并在15达因/平方厘米时达到峰值；（3）间充质干细胞经三种信号通路抑制剂预处理后，渥曼青霉素组和PD98059组中MMP-9表达无明显变化，但在SB202190组中MMP-9表达受到显著抑制。本研究表明，切应力可诱导大鼠骨髓间充质干细胞中MMP-9的表达；MMP-9表达量与刺激时间和切应力强度密切相关；且p38丝裂原活化蛋白激酶信号通路在此过程中起关键作用。
