The Mandibular Cartilage Metabolism is Altered by Damaged Subchondral Bone from Traumatic Impact Loading
The Mandibular Cartilage Metabolism is Altered by Damaged Subchondral Bone from Traumatic Impact Loading
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DOI：
10.1007/s10439-009-9696-z
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发表时间：
2009-07-01
影响因子：
3.8
通讯作者：
Tanne, Kazuo
中科院分区：
文献类型：
--
作者：
Lin, Yu-Yu;Tanaka, Nobuaki;Tanne, Kazuo
颞下颌关节骨关节炎是一种由过度的外部负荷引起的退行性疾病。近年来，有研究表明，创伤性冲击载荷引起的矿化软骨下骨的损伤是软骨退变发生和发展的原因。到目前为止，我们已经假设，细胞因子释放从受损的软骨下骨从冲击负荷影响软骨catelation在病理条件下。将200 GW的冲击器掉落到猪下颌骨髁突的顶部。器官培养2天后，我们通过组织学和生化实验研究了软骨下骨和软骨之间的联系。冲击载荷诱导IL-1 β的表达，化学和显着上调IL-1 α和IL-1 β mRNA水平在软骨下骨。我们证实了在软骨细胞中II型胶原和聚集蛋白聚糖mRNA表达的显着减少，通过与成骨细胞共培养后的冲击加载，和显着增加IL-1 β的mRNA和蛋白表达的冲击加载的软骨下骨的软骨下成骨细胞。与IL-1 β、IL-6和TNF-α预处理的成骨细胞共培养后，软骨细胞中II型胶原、聚集蛋白聚糖和X型胶原的mRNA表达显著降低。其中，经IL-1 β预处理的成骨细胞对软骨细胞的影响最强。IL-1 β处理的成骨细胞对软骨细胞MMP-1 mRNA表达的促进作用最明显。这些结果表明，TMJ受到冲击负荷可以直接增加IL-1 β在软骨下区域的合成，随后改变邻近软骨的代谢，并可能最终导致TMJ-OA的发病和进展。
Osteoarthritis (OA) in the temporomandibular joint (TMJ) is a degenerative disease caused by excessive external loading. Recently, it was reported that the damage in the mineralized subchondral bone caused by traumatic impact-loading is responsible for the initiation and progression of cartilage degeneration. Thus far, we have hypothesized that cytokines released from damaged subchondral bone from impact-loading affect the cartilage catabolism under pathological conditions. An impactor of 200 gw was dropped onto the top of a porcine mandibular condyle. After organ culture for 2 days, we investigated the association between the subchondral bone and cartilage using histological and biochemical experiments. The impact-loading induced the expression of IL-1 beta immunohistochemically and prominently up-regulated IL-1 alpha and IL-1 beta mRNA levels in subchondral bone. We confirmed a significant decrease in type II collagen and aggrecan mRNA expressions in chondrocytes by co-culture with osteoblasts after impact-loading, and significant increase in mRNA and protein expressions of IL-1 beta in subchondral osteoblasts from impact-loaded subchondral bone. The mRNA expressions of type II collagen, aggrecan, and type X collagen in chondrocytes were decreased significantly by the co-culture with osteoblasts pre-treated by IL-1 beta, -6, and TNF-alpha. Among them, osteoblasts pre-treated by IL-1 beta affected chondrocytes most strongly. It was also shown that IL-1 beta-treated osteoblasts enhanced the MMP-1 mRNA level most markedly in chondrocytes among the four cytokines. These results suggest that the TMJ subjected to impact-loading can increase directly IL-1 beta synthesis in the subchondral region, subsequently altering the metabolism of adjacent cartilage and may eventually resulting in the onset and progression of TMJ-OA.