炎症状态下张应力对成骨细胞基质金属蛋白酶-13和金属蛋白酶抑制因子-1表达的影响

The expression of MMP-13/TIMP-1 affected by mechanical strain under inflammatory environment in MC3T3-E1

目的观察炎症状态下周期性张应力对小鼠成骨细胞（MC3T3-E1细胞）基质金属蛋白酶-13和金属蛋白酶抑制因子-1表达的影响。方法收集100ng／ml的经牙龈卟啉单胞菌脂多糖（P．g-LPS）刺激小鼠单核巨噬细胞（RAW264．7细胞）24h后培养上清液，以20％稀释浓度作用于MC3T3-E1细胞24h，采用四点弯曲细胞力学加载仪对正常培养与炎症状态下培养的MC3T3-E1细胞分别加载张应力0h（对照组）、1h、3h、6h，采用荧光定量聚合酶链反应（realtimePCR）和免疫组化法检测基质金属蛋白酶-13和金属蛋白酶抑制因子-1的mRNA及蛋白水平表达的变化。结果炎症状态下周期性张应力作用于小鼠成骨细胞后，加力组基质金属蛋白酶-13和金属蛋白酶抑制因子-1的mRNA和蛋白表达量较非炎症状态下显著增加，并随着时间的延长而不断增加，且不同时间段的表达差异有统计学意义（P〈0．05）。结论炎症状态下张应力可显著影响成骨细胞基质金属蛋白酶-13和金属蛋白酶抑制因子-1的表达，从而为炎症状态与张应力共同作用下基质金属蛋白酶-13和金属蛋白酶抑制因子-1参与牙周组织细胞外基质代谢提供了理论依据。

Objective To investigate the gene and protein expression of MMP-13 and TIMP-1 induced by mechanical strain in inflammatory environment in MC3T3-E1. Methods Monocyte- macrophage cells（RAW264. 7） from mouse were stimulated by pgLPS（100 ng/ml） for 24 hours, then the supernatant was collected. Osteoblast of mouse（MC3T3-E1） was stimulated by 20% concentration of supernatant for 24 hours, the mechanical strain（cyclic compressive forces via a four-point bending system） was used for 0（control）, 1,3,6 hours, the gene and protein expression of MMP-13/TIMP-1 were detected through real time PCR（RT-PCR） and Immunohistochemistry, respectively. Results Compared with the controls, the gene and protein expression of MMP-13 and TIMP-1 was obviously increased, and has positive correlation with time after stimulated by mechanical strain in MC3T3-E1 in inflammatory environment, the difference was significant （P 〈 0. 05 ）. Conclusions The current results indicated that mechanical strain will significantly affect the expression of MMP-13 and TIMP-1 in inflammatory environment, The results suggested that external force in inflammatory environment may affect ECM metabolism depending on the functional role of MMP-13 and TIMP-1.