Clarification of the Mechanisms that Causes Internal Derangement of the Temporomandibular Joint

为了分析机械环境对大鼠颞下颌关节(TMJ)主要细胞外基质成分基因和蛋白表达的影响，采用Western blotting、免疫组织化学和实时荧光定量RT-PCR(Real-time Polymerase Chain Reaction，Real-time Polymerase Chain Reaction)技术，检测了TMJ中蛋白多糖核心蛋白在出生后发育过程中的表达和定位。主要研究结果如下：1.定量RT-PCR结果显示，Biglycan和Verscan基因的mRNA表达在出生后达到高峰，随着生长发育逐渐降低，而核心蛋白聚糖基因的表达随着生长发育而增加。2.在四种变态中，V0、V1和V3随生长发育而减少，V2在8周时达到峰值，然后逐渐下降。Western blotting结果显示，随着培养时间的延长，核心蛋白聚糖的基因表达迅速下降，而核心蛋白聚糖的基因表达则呈上升趋势。4.免疫组织化学研究表明，Biglycan在TMJ发育过程中呈均匀分布。与之相反，核心蛋白和乳胶蛋白的定位存在区域差异，核心蛋白和双聚糖在椎间盘中央的染色较弱，而在前、后外周附着体的染色较强，主要受张力力的影响。这些结果表明，发育期大鼠TMJ盘蛋白多糖的表达存在着与生长相关的变化和区域差异，可能反映了口面部功能发育引起的生物力学环境的改变。为了了解S的发病机制，有必要对食物一致性的影响进行进一步的研究。

To analyse the effects of mechanical environments on gene and protein expressions of major extracellular matrix components in rat temporomandibular joint (TMJ), expression and localization of the core proteins of proteoglycans in the TMJ discs during postnatal development were examined, using Western blotting, immunohistochemistry and rapid-cycle real-time RT-PCR (Real-time Polymerase Chain Reaction). The obtained results were followings; 1. Quantitative RT-PCR showed that mRNA expressions of biglycan and versican were peak after birth and gradually decreased with growing, while decorin mRNA increased with growing. 2. Among four versican isoforms, V0, V1 and V3 decreased with growing, while V2 peaked at 8 weeks and then gradually decreased.3. Western blotting showed that mRNA expression of rapidly decreased with growing, while mRNA of decorin increased. 4. An immunohistochemical study showed that biglycan was evenly distributed in the TMJ dsics throughout the growing stage. In contrast; localization of decorin and versican showed the regional differences; the stainingfor decorin and biglycan was weak in the central part of the discs and intense in the anterior and posterior peripheral attachments, which would mainly experience tensile forces. These results demonstrate that the growth-related changes and regional differences exist in the expression of proteoglycans in the TMJ discs of growing rats, which probably reflect the alteration of biomechanical environments caused by development of orofacial functions. Further study concerning the effects of food consistency would be necessary to understand mechanisms of temporomandibular joint diseases (TMD)s.