康复学报 (Oct 2023)
Effects of Electroacupuncture at Fengchi Acupoint on Myosatellite Cells and TLR4/MyD88/NF-κB Signaling Pathway in Chronic Cervical Muscle Injury Rats
Abstract
ObjectiveTo observe effects of electroacupuncture at Fengchi acupoint on expression of myosatellite cells, myogenic determining factor (MyoD), proliferating cell nuclear antigen (PCNA), Toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88) and nuclear factor-kappa B p65 (NF-κBp65) protein in rat with chronic cervical muscle injury, so as to explore possible mechanism of electroacupuncture in promoting the repair of chronic cervical muscle injury.MethodsTen Wistar rats were selected from 45 Wistar rats as blank group, and the remaining rats were divided into model group, electroacupuncture group (EA group) and meloxicam group according to random number table method, with 10 rats in each group (5 rats were unsuccessful in modeling). Chronic cervical muscle injury model of rats was established by long-term head flexion fixation and hypertonic saline injection. After 3 months of modeling, the morphological changes of posterior cervical muscle were observed by ultrasonic diagnostic detector. The success of modeling was verified by EMG. The EA group received electroacupuncture at Fengchi acupoint on both sides, 25 min each time, once a day, for 10 consecutive days as one course of treatment, with an interval of two days between courses of treatment, for 2 courses of treatment. After intervention, the posterior cervical muscle tissue of rats in each group was collected and the morphological changes of posterior cervical muscle tissue were observed under electron microscope. The protein contents of PCNA, MyoD, TLR4, MyD88 and NF-κBp65 were detected by immunohistochemistry.Results1) Morphological detection: Compared with the blank group, ultrasonic diagnosis results of the model group showed that tissue of posterior cervical muscle of rats was discontinuous and thickness was significantly narrower. Electrophysiological test results showed that amplitude and frequency of electromyographic significantly decreased in the model group. Compared with the blank group, muscle electron microscopy results of the model group showed that the arrangement of myofibrils was discontinuous, some mitochondria were swollen, and there were breaks between muscle fibers and muscle segments, and there were vacuoles. Compared with the model group, the EA group showed that myofibrils were clearly visible, cross-section of the myofibrils was punctured, sarcomere and serosa were intact, some mitochondria were swollen, and a few of them had vacuoles at the fracture of myofibrils. Myofibril structure of the meloxicam group was occasionally irregular, with vacuoles at the fracture of myofibril and a small amount of mitochondrial swelling. 2) Immunohistochemistry: Compared with the blank group, expression of PCNA and MyoD in model group was weakly positive, and protein expression of TLR4, MyD88 and NF-κBp65 significantly increased (P<0.05). Compared with the model group, the protein expression levels of PCNA and MyoD in the EA and meloxicam groups significantly increased (P<0.05), protein expression levels of TLR4, MyD88 and NF-κBp65 significantly decreased (P<0.05). There was no significant difference in expression levels of PCNA, MyoD, TLR4, MyD88 and NF-κBp65 between the EA and meloxicam groups (P>0.05).ConclusionThe treatment of chronic cervical muscle injury by electroacupuncture at Fengchi acupoint may be related to promoting the proliferation and differentiation of myosatellite cells, and the mechanism may be achieved by regulating the TLR4/MyD88/NF-κB signal transduction pathway.
