基于Piezo1/p38MAPK/ERK5力敏感通路探讨针刀干预膝关节骨关节炎兔膝关节软骨退化的作用机制OA

Objective To observe the effect of acupotomy on the articular cartilage in rabbits with knee osteoarthritis(KOA)and explore its mechanism for delaying cartilage degeneration based on the mechanosensitive Piezo1/p38 mitogen-activated protein kinase(p38MAPK)/extracellular signal-regulated kinase 5(ERK5)signaling pathway.Methods Twenty-four New Zealand rabbits were randomly divided into a blank group,a model group,an acupotomy group,and an acupotomy+agonist group,with 6 rabbits in each group.Using a modified Videman method,KOA models were prepared in the model group,acupotomy group,and acupotomy+agonist group.In the acupotomy group,the conventional acupotomy was delivered,targeting nodules or cord-like tissues around the knee joint.In the acupotomy+agonist group,2 h before acupotomy,Piezo1-specific agonist Yoda1(0.355 mg/mL,0.5 mL per injection)was injected into articular cavity,and the other procedures were same as the acupotomy group.The intervention was administered once weekly and for 3 consecutive weeks in each group.Before and after intervention,the Lequesne MG score was used to assess the improvements in the local knee joint symptoms,physical signs,and functions in each group.After intervention,safranin O-fast green staining was employed to observe the morphology of cartilage tissue of knee joint.The contents of cartilage degradation products,cartilage oligomeric matrix protein(COMP)and C-terminal telopeptide of type Ⅱ collagen(CTX-Ⅱ)in serum and synovial fluid of knee joint were detected by ELISA.Western blot was used to detect the protein expression levels of type Ⅱ collagen(Col-Ⅱ),Aggrecan,Piezo1,p38MAPK,and ERK5 in the cartilage tissue.Results Before intervention,compared with the blank group,the Lequesne MG scores increased in the model,acupotomy,and acupotomy+agonist groups(P＜0.01).After intervention,compared with the blank group,the model group showed a higher Lequesne MG score(P＜0.01),and when compared with the model group and acupotomy+agonist group,the acupotomy group exhibited a lower Lequesne MG score(P＜0.05).Compared with the blank group,the model group and acupotomy+agonist group showed the markedly reduced safranin O staining of the cartilage matrix,non-uniform and clustered distribution of chondrocytes,unclear cartilage structural layers,and disordered and blurred tidemarks.When compared with the model group and acupotomy+agonist group,the acupotomy group demonstrated more uniform red safranin O staining of the cartilage matrix,relatively uniform and orderly distribution of chondrocytes,clearer cartilage structural layers,and restored tidemarks.In comparison with the blank group,the contents of COMP and CTX-Ⅱ in the serum and synovial fluid were elevated in the model group(P<0.01).Compared with the model group and the acupotomy+agonist group,the acupotomy group showed the decrease in COMP and CTX-Ⅱ(P＜0.01).Compared with the blank group,the protein expression of Col-Ⅱ and Aggrecan in the cartilage decreased(P＜0.01),while that of Piezo1,p38MAPK,and ERK5 increased(P＜0.01)in the model group.Compared with the model group,the acupotomy group and the acupotomy+agonist group showed the increase in the protein expression of Col-Ⅱand Aggrecan(P＜0.01)and the decrease in the protein expression of Piezo1,p38MAPK,and ERK5(P＜0.01).When compared with the acupotomy+agonist group,the acupotomy group demonstrated the higher protein expression of Col-Ⅱand Aggrecan(P＜0.01)and lower expression of Piezo1,p38MAPK,and ERK5(P＜0.01).Conclusion Acupotomy can alleviate articular cartilage degeneration in KOA model rabbits.The mechanism may be associated with regulating the Piezo1/p38MAPK/ERK5 mechanosensitive pathway,exerting mechano-biological effect,inhibiting extracellular matrix degradation,maintaining articular cartilage metabolic homeostasis,thereby attenuating cartilage degeneration and injury,and promoting the repair of degenerated articular cartilage.