异常机械负荷加重大鼠颞下颌关节骨关节炎的组织病理学研究

Histopathology of temporomandibular joint osteoarthritis in rats under abnormal mechanical load

摘要:

目的 研究异常机械负荷在大鼠颞下颌关节软骨退变中的作用。方法 36只8周龄雌性SD大鼠随机分为4组，分别为对照组（control group，Con组）、Ⅱ型胶原蛋白酶组（collagenase type Ⅱ group，CⅡ组）、大张嘴组（wide mouth opening group，MS组）和Ⅱ型胶原酶+大张嘴组（collagenase type Ⅱ+wide mouth opening group，CⅡ+MS组）。HE染色、番红O-固绿染色观测软骨组织病理学变化，免疫组化实验检测炎性因子基质金属蛋白酶3（matrix metalloproteinase 3，MMP3）和聚蛋白多糖酶5（a disintegrin and metalloproteinase with thrombospondin motifs 5，ADAMTS5）的表达。结果 与Con组相比，CⅡ、MS和CⅡ+MS组大鼠颞下颌关节软骨后区总厚度、钙化层厚度和番红O阳性面积比均显著降低（均P<0.05），CⅡ、MS和CⅡ+MS组中MMP3和ADAMTS5的阳性表达均显著增高（均P=0.000）；与CⅡ和MS组相比，CⅡ+MS组软骨钙化层厚度显著降低（均P=0.000），ADAMTS5表达显著增高（均P=0.000）；MS和CⅡ+MS组软骨后区潮线呈波浪状。结论 异常机械负荷促使髁突软骨后区退变及改建，这将有助于异常负荷致颞下颌关节骨关节炎的机制研究。

Abstract:

Objective To investigate the impact of abnormal mechanical load on cartilage degeneration of the temporomandibular joint （TMJ） in rats.Methods A total of 36 female Sprague-Dawley rats，aged 8 weeks，were randomly divided into control group（Con group），collagenase type Ⅱ group（CⅡ group），wide mouth opening group（MS group），and collagenase type Ⅱ+wide mouth opening group （CII+MS group）. HE staining and safranin O-fast green staining were used to observe the histopathological changes of cartilage， and immunohistochemistry was used to measure the expression levels of the inflammatory factors matrix metalloproteinase 3（MMP3） and A disintegrin and metalloproteinase with thrombospondin motifs 5（ADAMTS5）.Results Compared with the Con group，the CII，MS， and CII+MS groups had significant reductions in the total thickness，calcified layer thickness， and safranin O-positive area ratio of the TMJ posterior zone（P<0.05） and significant increases in the positive expression of MMP3 and ADAMTS5（P=0.000）. Compared with the CⅡ and MS groups，the CⅡ+MS group had a significant reduction in the calcified layer thickness of cartilage（P=0.000） and a significant increase in the expression of ADAMTS5（P=0.000）. The MS and CII+MS groups had a wavy tidal line in the posterior zone of cartilage.Conclusion Abnormal mechanical load promotes the degeneration and reconstruction of the posterior zone of condylar cartilage，which may help with the research on the mechanism of TMJ osteoarthritis caused by abnormal mechanical load.