Han Hong, Li Ming, Liu Huilin, Li Haohan
Department of Rehabilitation Medicine, Wuhan Fourth Hospital, Wuhan, Hubei 430000, P.R. China.
Department of Rehabilitation, Hubei Provincial Hospital, Wuhan, Hubei 430071, P.R. China.
Exp Ther Med. 2021 Dec;22(6):1457. doi: 10.3892/etm.2021.10892. Epub 2021 Oct 19.
Skeletal muscle injury is one of the most common sports injury, which accounts for ~40% of all sports-related injuries among the elderly. In addition, cases of full recovery from treatment are rare. Although electroacupuncture (EA) is an integral aspect of traditional Chinese medicine, the effects of EA on skeletal muscle fibrosis and the possible underlying mechanism remain unclear. To investigate the effect and potential mechanism of EA on skeletal inflammation, collagen deposition and macrophage function, a skeletal muscle injury model was established by injecting 100 µl cardiotoxin into the anterior tibial muscle of Sprague Dawley rats. The animals were randomly divided into the following three groups: Control, model and EA. The expression of inflammation-related factors (IL-6, IL-4, IL-33, IL-10 and TNF-α) were measured using ELISA. H&E staining, Masson's staining and immunohistochemistry (collagen II, Axin2 and β-catenin) were performed to assess collagen deposition and fibrosis in the muscle tissues. Additionally, immunofluorescence was performed to measure the ratio of M to M macrophages. Western blotting was performed to examine the activity of the TGF-β1/Smad3/p38/ERK1/2 pathway. Compared with that in the control rats, the mental state, such as the degree of activity and excitement, of the model rats deteriorated, with clear activity limitations. Compared with those in the model rats, EA-treated rats exhibited improved mental status and activity, reduced levels of IL-6, IL-4 and TNF-α, reduced collagen deposition and fibrosis, in addition to increased expression of IL-33 and IL-10. This improvement became increasingly evident with prolonged intervention time. EA also promoted the transformation of macrophages from the M into the M sub-type, where the M/M ratio on day 7 was lower compared with that on day 14. Western blotting results showed that compared with that in the model rats, the expression of TGF-β1, MMP-2, MMP-7 and the activation of Smad3 and p38 was decreased in EA-treated rats, whilst the activation of ERK1/2 was significantly elevated. In conclusion, EA can inhibit inflammation and collagen deposition whilst promoting the transformation of macrophages from the M into the M sub-type. The underlying mechanism was found to be associated with TGF-β1/Smad3/p38/ERK1/2 signaling.
骨骼肌损伤是最常见的运动损伤之一，在老年人所有与运动相关的损伤中占比约40%。此外，治疗后完全康复的病例很少见。尽管电针是中医的一个重要方面，但其对骨骼肌纤维化的影响及潜在机制仍不清楚。为了研究电针对骨骼肌炎症、胶原沉积和巨噬细胞功能的影响及潜在机制，通过向Sprague Dawley大鼠的胫前肌注射100 μl心脏毒素建立骨骼肌损伤模型。将动物随机分为以下三组：对照组、模型组和电针组。使用酶联免疫吸附测定法（ELISA）检测炎症相关因子（白细胞介素-6、白细胞介素-4、白细胞介素-33、白细胞介素-10和肿瘤坏死因子-α）的表达。进行苏木精-伊红（H&E）染色、Masson染色和免疫组织化学（胶原蛋白II、Axin2和β-连环蛋白）检测，以评估肌肉组织中的胶原沉积和纤维化。此外，进行免疫荧光检测以测量M1与M2巨噬细胞的比例。进行蛋白质免疫印迹法检测转化生长因子-β1（TGF-β1）/Smad3/p38/细胞外信号调节激酶1/2（ERK1/2）信号通路的活性。与对照大鼠相比，模型大鼠的精神状态，如活动和兴奋程度恶化，活动明显受限。与模型大鼠相比，电针治疗的大鼠精神状态和活动得到改善，白细胞介素-6、白细胞介素-4和肿瘤坏死因子-α水平降低，胶原沉积和纤维化减少，此外白细胞介素-33和白细胞介素-10的表达增加。随着干预时间延长，这种改善越来越明显。电针还促进巨噬细胞从M1型向M2型转变，第7天的M1/M2比值低于第14天。蛋白质免疫印迹结果显示，与模型大鼠相比，电针治疗的大鼠中TGF-β1、基质金属蛋白酶-2（MMP-2）、基质金属蛋白酶-7（MMP-7）的表达以及Smad3和p38的激活降低，而ERK1/2的激活显著升高。总之，电针可抑制炎症和胶原沉积，同时促进巨噬细胞从M1型向M2型转变。发现其潜在机制与TGF-β1/Smad3/p38/ERK1/2信号传导有关。
