目的 探讨脂多糖(LPS)对小鼠成骨细胞MC3T3-E1中基质金属蛋白酶-13（MMP-13）表达的影响及其分子机制。方法 采用LPS处理传代培养的小鼠成骨细胞MC3T3-E1，Western blotting检测MC3T3-E1中MMP-13及转录因子C/EBPβ、核因子κB （NF-κB）及其抑制蛋白IκB、肿瘤坏死因子-α （TNF-α）、白介素-6 （IL-6)的表达；观察使用NF-κB特异性抑制剂Bay11-7082干预及特异性siRNA沉默C/EBPβ、TNF-α和IL-6表达对MC3T3-E1中MMP-13表达的影响。结果 Western blotting检测结果显示：LPS能够诱导MC3T3-E1中MMP-13高表达，促进NF-κB、C/EBPβ、TNF-α和IL-6的表达和活化，抑制IκB表达；Bay11-7082干预及siRNA沉默TNF-α表达能有效抑制MC3T3-E1中TNF-α和MMP-13的表达，而siRNA沉默C/EBPβ和IL-6表达对MC3T3-E1中MMP-13的表达无明显影响。结论 LPS通过NF-κB/TNF-α诱导MMP-13在成骨细胞MC3T3-E1中高表达，这为阐明牙周炎的发病机制奠定了基础。

Objective To investigate the effects of lipopolysaccharide (LPS) on the expression of matrix metalloproteinases-13 (MMP-13) in mouse osteoblast MC3T3-E1 and their molecular mechanism. Methods The osteoblast MC3T3-E1 of subculture mouse was treated by LPS. Expressions of MMP-13 and transcription factor C/EBPβ, nuclear factor-κB (NF-κB) and its inhibitory protein IκB, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in MC3T3-E1 cells were detected by the Western blotting. The effects of specific inhibitor Bay11-7082 of NF-κB and expressions of specific siRNA silencing C/EBPβ, TNF-α, and IL-6 on the expression of MMP-13 in MC3T3-E1 cells were observed. Results The results of Western blotting showed that LPS induced high level expression of MMP-13 in MC3T3-E1 cells, promoted the expression and activation of NF-κB, C/EBPβ, and IL-6, and inhibited the expression of IκB. Expressions of TNF-α and MMP-13 in MC3T3-E1 cells could be effectively inhibited by Bay11-7082 and siRNA silencing TNF-α. While the siRNA silencing C/EBPβ and the expression of IL-6 did not significantly influence the expression of MMP-13 in MC3T3-E1 cells. Conclusion LPS can induce high level expression of MMP-13 in osteoblast MC3T3-E1 by NF-κB/TNF-α, which helps clarifying the pathogenesis of periodontitis.