Huser Camille A M, Davies M Elisabeth
Comparative Orthopaedics Research Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, United Kingdom.
J Orthop Res. 2006 Apr;24(4):725-32. doi: 10.1002/jor.20111.
The objective of this study was the development and characterization of an in vitro model of the initiation of traumatic osteoarthritis (OA). Articular cartilage was obtained from seven healthy horses and from four horses diagnosed with OA. Cartilage disks were subjected to a single-impact load (500 g from 25, 50, or 100 mm) using a simple drop-tower device and cultured in vitro for up to 20 days. Cartilage sections were examined histologically to observe surface damage and proteoglycan loss. Percentage cell death was determined using TUNEL, release of glycosaminoglycans (GAG) to the medium was measured using the DMMB assay, and percentage weight gain calculated. Following a single-impact load and subsequent culture in vitro, articular cartilage explants demonstrated characteristic surface damage, proteoglycan loss, and chondrocyte death. This closely resembled degenerative changes observed in OA cartilage samples. A kinetic study showed that these degenerative changes (increased weight gain, GAG release into the medium, and chondrocyte death) were initiated within 48 h following impact and increased with recovery time in culture. These parameters were proportional to impact height, that is, impact energy. In conclusion, articular cartilage disks subjected to a single-impact load followed by 48 h of recovery time in culture in vitro developed traumatic OA-like changes. These changes can be quantified and compared, making the in vitro single-impact load model a useful tool for the elucidation of the early molecular pathways involved in the process leading from trauma to cartilage degeneration.
本研究的目的是建立并表征创伤性骨关节炎（OA）起始阶段的体外模型。从7匹健康马和4匹被诊断为OA的马身上获取关节软骨。使用简单的落塔装置对软骨盘施加单次冲击负荷（从25、50或100毫米高度落下500克重物），并在体外培养长达20天。对软骨切片进行组织学检查，以观察表面损伤和蛋白聚糖损失。使用TUNEL法测定细胞死亡百分比，使用DMMB法测量糖胺聚糖（GAG）向培养基中的释放量，并计算重量增加百分比。在单次冲击负荷及随后的体外培养后，关节软骨外植体表现出特征性的表面损伤、蛋白聚糖损失和软骨细胞死亡。这与在OA软骨样本中观察到的退行性变化非常相似。一项动力学研究表明，这些退行性变化（重量增加、GAG释放到培养基中以及软骨细胞死亡）在冲击后48小时内开始，并随着培养恢复时间的延长而增加。这些参数与冲击高度成正比，即与冲击能量成正比。总之，经受单次冲击负荷并在体外培养48小时恢复时间的关节软骨盘出现了类似创伤性OA的变化。这些变化可以进行量化和比较，使得体外单次冲击负荷模型成为阐明从创伤到软骨退变过程中早期分子途径的有用工具。
