Effect of pressing Weizhong acupoint on the repair of lumbar muscle injury in rats was explored based on the Keap1-Nrf2 pathway
ZHANG Qi,MA Xin-long,ZHAO Na
Abstract:
Objective To investigate the effects on the structural changes of local tissues in rats with multifidus muscle injury by adopting the therapeutic method of regular acupressure at Weizhong acupoint and explore the mechanism of acupoint therapy for lumbar muscle injury based on the Nrf2 signaling pathway. Methods 40 SD rats were randomly divided into control group, model group, acupoint group, and the inhibitor group(n=10). Upon the successful modeling, the latter two groups received acupoint intervention using pressure sensors for a total of two weeks, while the control and model groups were not intervened. The inhibitor group was injected with the Nrf2 pathway inhibitor brusatol (BRU) before acupuncture. After the intervention, structural differences in the lumbar multifidus muscle were detected via ultrasound. Bilateral multifidus muscle tissues and serum were collected to observe muscle HE staining and serum inflammatory factors IL-18, IL-1β. Furthermore, the levels of creatine kinase (CK), cyclooxygenase-2 (COX-2), caspase-3, and mechano growth factor (MGF), as well as cytoplasmic protein (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), and desmin protein and mRNA expression levels were measured. Results Compared with the control group, the model group showed local muscle swelling on ultrasound, and significant muscle fiber damage (P <0.01). HE staining revealed obvious muscle fiber damage and edema, and serum inflammatory factor levels were elevated. The expression of CK, COX-2, Caspase-3 proteins, and mRNA was increased (P <0.01), and the expression of Keap1, Nrf2, and Desmin proteins and mRNA was also elevated (P <0.01). No significant difference was observed in the expression of MGF protein and mRNA (P >0.05).Compared with the model group, the acupoint group showed lighter local muscle swelling on ultrasound, less inflammation and edema in HE staining, lower levels of serum inflammatory factors, and reduced expression of CK, COX-2, and Caspase-3 proteins and mRNA. The expression of MGF, Keap1, Nrf2, and Desmin proteins and mRNA was increased (P <0.01). Compared with the acupoint group, the inhibitor group showed more severe local muscle swelling on ultrasound, pronounced inflammation and edema in HE staining, higher levels of serum inflammatory factors, and increased expression of CK, COX-2, and Caspase-3 proteins and mRNA (P <0.01). The expression of Keap1, Nrf2, and Desmin proteins and mRNA was decreased (P <0.01). Conclusion Acupressure at the Weizhong point can improve the pathological state of inflammatory damage in the multifidus muscle of rats with lumbar muscle injury to some extent and restore the damaged tissue structure. Acupressure stimulation increases the expression of MGF and activates the Nrf2 pathway, downregulating the expression of myocyte repair proteins. This may be one of the mechanisms by which acupressure at the Weizhong point exerts its therapeutic effects on lumbar muscle injury.
