Effects of mechanical strain on oxygen free radical system in bone marrow mesenchymal stem cells from children
Effects of mechanical strain on oxygen free radical system in bone marrow mesenchymal stem cells from children
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DOI：
10.1016/j.injury.2010.11.015
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发表时间：
2011-08-01
影响因子：
2.5
通讯作者：
Ni, Guoxin
中科院分区：
文献类型：
--
作者：
Li, Runguang;Chen, Bin;Ni, Guoxin
背景：人们普遍认为，生理负荷通过增加成骨细胞活性和伴随的破骨细胞活性减少来刺激新骨形成，有利于维持骨骼完整性。然而，过度或非生理负荷与骨损伤有关，包括应力性骨折和骨质疏松性骨折，从而导致骨功能能力下降。众所周知，活性氧（ROS）的过度产生是许多疾病状态下观察到的组织损伤的重要因素。本研究的目的是研究机械应变对儿童骨髓间充质干细胞 (MSC) 中氧自由基系统 [ROS、超氧化物歧化酶 (SOD) 和丙二醛 (MDA)] 的影响。方法：为了确定极端水平的机械应变是否会增强 ROS 合成，我们对 MSC 施加了不同强度的循环拉伸拉伸。 MSCs经机械应变刺激后，采用流式细胞仪（FCM）检测细胞内2,7-二氯二氢荧光素（DCFH）荧光探针标记的ROS，并分别采用黄嘌呤氧化酶法和硫代巴比妥酸法检测SOD活性和MDA水平。结果：对儿童MSCs施加极限水平（>12%）的机械应变增强ROS合成，降低SOD活性，升高MDA，以时间和幅度依赖的方式。结论：这些数据表明，循环拉伸应变幅度过大（> 12%）可能会诱导氧自由基不平衡，从而导致细胞毒性。这些发现可能对骨科实践具有临床意义。 (C) 2010 Elsevier Ltd. 保留所有权利。
Background: Physiological loading is widely believed to be beneficial in maintaining skeletal integrity by stimulating new bone formation through increases in osteoblastic activity and concomitant decreases in osteoclastic activity. However, excessive or nonphysiological loading is associated with bone injuries, including stress fractures and osteoporotic fractures, thereby leading to a decreased functional capacity of bone. It is known that the excessive generation of reactive oxygen species (ROS) is a significant factor underlying tissue injury observed in many disease states. The aim of this study was to study the effects of mechanical strain on oxygen free radical system [ROS, superoxide dismutase (SOD) and malondialdehyde (MDA)] in bone marrow mesenchymal stem cells (MSCs) from children.Methods: To determine whether extreme levels of mechanical strain enhance ROS synthesis, we loaded cyclic tensile stretch of varying magnitude on MSCs. After MSCs were stimulated by mechanical strain, ROS labelled with 2,7-dichlorodihydrofluorescein (DCFH) fluorescent probe in cells were detected by flow cytometry (FCM) whilst SOD activity and MDA level were detected by xanthine oxidase method and thiobarbituric acid method, respectively.Results: Extreme levels (>12%) of mechanical strain applied to children's MSCs enhanced ROS synthesis, decreased the activity of SOD and increased the level of MDA, in a time- and magnitude-dependent fashion.Conclusions: These data suggest that excessive magnitude of cyclic tensile strain (> 12%) could induce oxygen free radical disequilibrium, resulting in cytotoxicity. The findings may have clinical implications for orthopaedic practice. (C) 2010 Elsevier Ltd. All rights reserved.