The effect of corticosteroid on collagen expression in injured rotator cuff tendon
The effect of corticosteroid on collagen expression in injured rotator cuff tendon
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DOI：
10.2106/jbjs.e.00806
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发表时间：
2006-06-01
影响因子：
5.3
通讯作者：
Wezeman, Frederick H.
中科院分区：
文献类型：
--
作者：
Wei, Anthony S.;Callaci, John J.;Wezeman, Frederick H.
背景：肩峰下皮质类固醇注射通常用于肩袖疾病的非手术治疗。皮质类固醇注射对损伤肩袖肌腱的影响尚未研究。我们的目的是通过分析iii型胶原表达比（一种肌腱损伤标志物）来表征肩袖肌腱对损伤的急性反应，并研究皮质类固醇对这种反应的影响。方法：将60只Sprague-Dawley大鼠随机分为对照组、肌腱损伤组、类固醇治疗组和肌腱损伤+类固醇治疗组。6只大鼠作为假对照组。单侧肌腱损伤产生全层缺损，其宽度占甘下肌腱总宽度的50%，距其肱骨止点5mm。将单剂量甲基强的松龙（0.6 mg/kg）进行类固醇治疗，相当于给人的剂量，在直接可见的情况下注射到肩峰下间隙。类固醇治疗是在损伤和类固醇治疗组的大鼠产生损伤后进行的。在损伤后1周、3周和5周，用实时聚合酶链反应（real-time polymerase chain reaction）定量从肌腱中分离的总RNA，并使用型和iii型胶原和核糖体18s RNA的引物。结果：对照组和假手术组在所有时间点iii型与i型胶原表达比保持在基线水平。1周时，肌腱损伤组iii型与i型胶原表达比（p = 0.017）和肌腱损伤与类固醇治疗组（p = 0.003）较对照水平增加4倍以上。两组在三周时的比率仍然大于对照组的两倍（p = 0.003和p = 0.037），并在五周时恢复到基线。有趣的是，接受类固醇治疗的组iii型胶原蛋白与型胶原蛋白的表达比增加了4.5倍（p = 0.001），没有对肌腱造成结构性损伤。这一比率在三周后恢复到基线水平。结论：单剂量皮质类固醇不会改变大鼠肌腱损伤的急性期反应。然而，相同剂量的类固醇在未损伤肌腱中引发的短期反应相当于结构损伤。
Background: Subacromial corticosteroid injections are commonly used in the nonoperative management of rotator cuff disease. The effects of corticosteroid injection on injured rotator cuff tendons have not been studied. Our aims were to characterize the acute response of rotator cuff tendons to injury through the analysis of the type-III to typed collagen expression ratio, a tendon injury marker, and to examine the effects of corticosteroid on this response.Methods: Sixty Sprague-Dawley rats were randomly assigned to four groups: control, tendon injury, steroid treatment, and tendon injury and steroid treatment. Six rats served as sham controls. Unilateral tendon injuries were created with full-thickness defects across 50% of the total width of the infraspinatus tendon, 5 mm from its humeral insertion. Steroid treatment with a single dose of methylprednisolone (0.6 mg/kg), equivalent to that given to humans, was injected into the subacromial space under direct visualization. Steroid treatment followed the creation of an injury in the rats in the injury and steroid treatment group. At one, three, and five weeks after the injury, the total RNA isolated from tendons was quantified with real-time polymerase chain reaction with use of primers for typed and type-III collagen and ribosomal 18s RNA.Results: The type-III to type-I collagen expression ratio remained at baseline at all time-points in the control and sham groups. At one week, the type-III to type-I collagen expression ratio increased more than fourfold above the control level in the tendon injury group (p = 0.017) and the tendon injury and steroid treatment group (p = 0.003). The ratio remained greater than twofold above the control at three weeks in both groups (p = 0.003 and p = 0.037) and returned to baseline at five weeks. Interestingly, the group that had steroid treatment only showed an increase of > 4.5-fold (p = 0.001) in the type-III to typed collagen expression ratio, without structural injury to the tendon. This ratio returned to baseline levels by three weeks.Conclusions: A single dose of corticosteroid does not alter the acute phase response of an injured rotator cuff tendon in the rat. However, the same steroid dose in uninjured tendons initiates a short-term response equivalent to that of structural injury.