目的:肩袖损伤是一种常见的损伤,包括炎症,局部撕裂,或完全撕裂肩袖肌腱。在肩袖撕裂(RCT)的情况下,肿瘤坏死因子-α(TNF-α)可以触发神经生长因子(NGF)的释放。TNF-α是影响肩袖活性的重要炎症介质,并且在RCT中观察到增加的NGF表达。因此,本研究旨在探讨抑制TNF-α是否可以通过NGF降低大鼠的行为反应和炎症水平。
方法:建立大鼠RCT模型,CatWalk步态分析系统用于行为评估。免疫组化法检测肌腱组织中NGF蛋白水平。苏木素-伊红(HE)染色观察组织病理学变化。采用免疫印迹法(WB)和定量实时聚合酶链反应(qRT-PCR)检测白细胞介素-1β(IL-1β)和环氧合酶-2(COX2)的表达。凋亡相关蛋白Bcl-2-X(Bax)的表达,B细胞淋巴瘤2(Bcl-2),使用WB检测半胱氨酸-天冬氨酸蛋白酶-3(Caspase-3)。氧化应激标志物,即活性氧(ROS),丙二醛(MDA),使用ELISA试剂盒定量组织中的超氧化物歧化酶(SOD)。
结果:在RCT模型中,NGF蛋白表达升高,冈上肌组织明显萎缩,并观察到大量的脂肪浸润。IL-1β水平,COX2,细胞凋亡,氧化应激均增加。TNF-α抑制导致NFG表达降低,组织纤维化减少,和改善肌腱萎缩。此外,当TNF-α被抑制时,IL-1β和Cox2的表达降低,细胞凋亡和氧化应激降低。结果表明,抑制TNF-α有可能降低大鼠的炎症水平和行为反应。
结论:TNF-α可通过NGF影响RCT大鼠的行为和炎症,抑制TNF-α可以改善肩袖损伤。
OBJECTIVE: Rotator cuff injury is a common injury that includes inflammation, partial tearing, or complete tearing of the rotator cuff tendon. In cases of rotator cuff tears (RCTs), Tumor Necrosis Factor-alpha (TNF-α) can trigger the release of nerve growth factor (NGF). TNF-α is an important inflammatory mediator that affects rotator cuff activity and increased NGF expression is observed in RCTs. Therefore, this study aimed to investigate whether inhibition of TNF-α could reduce behavioural responses and inflammation levels in rats through NGF.
METHODS: A rat RCT model was established, and the CatWalk gait analysis system was used for behavioural assessment. Immunohistochemistry was used to detect NGF protein levels in tendon tissue. Hematoxylin eosin (HE) staining was used to observe histopathological changes. The expressions of Interleukin-1beta (IL-1β) and Cyclooxygenase-2 (COX2) were detected by western blotting (WB) and quantitative real-time polymerase chain reaction (qRT-PCR). The expression of apoptosis protein Bcl-2-associated X (Bax), B-cell lymphoma 2 (Bcl-2), and Cysteine-aspartic acid protease-3 (Caspase-3) were detected using WB. Oxidative stress markers, namely Reactive Oxygen Species (ROS), Malondialdehyde (MDA), and Superoxide Dismutase (SOD) were quantified in tissues using an ELISA kit.
RESULTS: In the RCT model, elevated NGF protein expression, noticeable atrophy in the supraspinatus muscle tissue, and substantial fat infiltration were observed. The levels of IL-1β, COX2, apoptosis, and oxidative stress were all increased. TNF-α inhibition resulted in decreased NFG expression, decreased tissue fibrosis, and improved tendon atrophy. Moreover, when TNF-α was inhibited, the expressions of IL-1β and Cox2 were reduced and both apoptosis and oxidative stress were decreased. The results showed that inhibiting TNF-α had the potential to reduce inflammation levels and behavioural responses in rats.
CONCLUSIONS: TNF-α can affect behaviour and inflammation in rats with RCTs through NGF, and TNF-α inhibition can improve rotator cuff injury.