Archambault J M, Jelinsky S A, Lake S P, Hill A A, Glaser D L, Soslowsky L J
Wyeth Discovery Research, 200 Cambridge Park Drive, Cambridge, Massachusetts 02140, USA.
J Orthop Res. 2007 May;25(5):617-24. doi: 10.1002/jor.20347.
The goals of this study were to investigate the response of the rat supraspinatus tendon to overuse at the molecular level using transcriptional profiling, and to identify potential markers of tendinopathy. Adult rats were subjected to an overuse protocol that consists of downhill running (10% grade) at 17 m/min for 1 h/day, 5 days/week, for a total of either 1, 2, or 4 weeks. Another group of rats served as nonrunning time 0 controls. Transcriptional profiling was performed on the supraspinatus and patellar tendons using an Affymetrix rat genome array. A gene was considered to be differentially expressed if the p value from an ANOVA test was less than 0.01 and the difference between runners and controls was at least twofold at any time point. The supraspinatus tendon had increased expression of well-known cartilage genes such as col2a1, aggrecan, and sox9. These genes were not regulated in the patellar tendon, an internal comparator. Few genes associated with inflammation, or angiogenesis, were differentially expressed, and no significant change in the regulation of matrix metalloproteinases was detected. The results of this study suggest that by expressing more cartilage genes, the tendon is converting toward a fibrocartilage phenotype as a result of the repetitive loading and repeated compression of the tendon as it passes through the acromial arch.
本研究的目的是使用转录谱分析在分子水平上研究大鼠冈上肌腱对过度使用的反应，并确定肌腱病的潜在标志物。成年大鼠接受一种过度使用方案，该方案包括以17米/分钟的速度在10%坡度的下坡跑，每天1小时，每周5天，总共进行1、2或4周。另一组大鼠作为非跑步时间0的对照组。使用Affymetrix大鼠基因组阵列对冈上肌腱和髌腱进行转录谱分析。如果方差分析测试的p值小于0.01，并且在任何时间点跑步组和对照组之间的差异至少为两倍，则认为一个基因存在差异表达。冈上肌腱中一些众所周知的软骨基因如col2a1、聚集蛋白聚糖和sox9的表达增加。这些基因在髌腱（内部对照）中没有受到调节。很少有与炎症或血管生成相关的基因存在差异表达，并且未检测到基质金属蛋白酶调节的显著变化。本研究结果表明，由于肌腱在穿过肩峰弓时受到重复加载和反复压缩，通过表达更多软骨基因，肌腱正在向纤维软骨表型转变。
