Gene expression of fibrinolytic factors urokinase plasminogen activator and plasminogen activator inhibitor-1 in rabbit temporo-mandibular joint cartilage with disc displacement.
Gene expression of fibrinolytic factors urokinase plasminogen activator and plasminogen activator inhibitor-1 in rabbit temporo-mandibular joint cartilage with disc displacement.
复制标题
兔颞下颌关节软骨椎间盘移位纤溶因子尿激酶纤溶酶原激活物和纤溶酶原激活物抑制物1基因的表达
作者：
J. Zhan;Z. Gu;Li‐qun Wu;Yin;Ji
背景
尿激酶纤溶酶原激活物系统被认为在与软骨和骨破坏相关的细胞外基质降解中起重要作用;然而，其在颞下颌关节紊乱病中的确切作用尚未阐明。本研究旨在观察兔颞下颌关节盘移位（DD）后关节软骨纤溶因子尿激酶纤溶酶原激活物（uPA）和纤溶酶原激活物抑制剂-1（派-1）的基因表达，探讨纤溶活性与关节软骨重塑的关系。
方法
78只家兔中36只右关节盘移位。分别于术后第4天和第1、2、4、8和12周处死动物。取右侧关节，采用原位杂交技术检测关节软骨uPA和派-1 mRNA的表达。
结果
在对照组，uPA和派-1在过渡带、肥大带和矿化带的软骨细胞中呈弱阳性共表达，而在增殖带和表浅带的软骨细胞中无杂交信号。最显著的是uPA和派-1 mRNA在术后4天的兔中在软骨退变开始时上调。uPA和派-1的杂交信号在术后2周最强。2周后uPA和派-1表达开始下降，12周时接近正常水平。
结论
uPA/派-1系统的表达与DD后髁突软骨的病理变化相一致。uPA/派-1系统可能是关节软骨重塑的重要介质之一。
BACKGROUND
The urokinase plasminogen activator system is believed to play an important role in degradation of the extracellular matrix associated with cartilage and bone destruction; however its precise roles in temporomandibular disorders have not yet been clarified. The aims of this study were to investigate the gene expression of fibrinolytic factors urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) in the articular cartilage of rabbit temporomandibular joint (TMJ) with disc displacement (DD) and to probe the relationship between fibrinolytic activity and cartilage remodeling.
METHODS
Disc displacement of right joints was performed in 36 of 78 rabbits under investigation. The animals were sacrificed at 4 days and 1, 2, 4, 8 and 12 weeks after surgery, respectively. The right joints of these animals were harvested and processed for the examination of mRNA expression of uPA and PAI-1 in articular cartilage using in situ hybridization techniques.
RESULTS
The expression of uPA and PAI-1 was co-expressed weakly in the chondrocytes from transitive zone to hypertrophic zone and mineralized zone, while no hybridizing signals were shown in proliferative zone and superficial zone in control rabbits. The most striking was the up-regulation of uPA and PAI-1 mRNA in 4-day rabbits postoperatively at the onset of cartilage degeneration. The strongest hybridizing signals for uPA and PAI-1 were seen in 2-week rabbits postoperatively. After 2 weeks, the expression of uPA and PAI-1 began to decrease and reached nearly normal level at 12 weeks.
CONCLUSIONS
The expression of the uPA/PAI-1 system coincides with the pathological changes in condylar cartilage after DD. The uPA/PAI-1 system may be one of the essential mediators in articular cartilage remodeling.