体外冲击波通过ERK1/2通路调控KOA兔软骨细胞自噬的机制OA

Objective Investigate the mechanism by which extracorporeal shockwave therapy modulates the extracellular signal-regulated kinase 1/2(ERK1/2)signaling pathway to regulate autophagy in chondrocytes using a rabbit model with knee osteoarthritis(KOA).Methods Forty New Zealand White rabbits were randomly assigned to four groups of 10 rabbits each using a pseudorandom number table:sham,model,extracorporeal shock wave therapy(ESWT),and ERK1/2 signaling pathway inhibitor(inhibitor)group.All groups except the sham group underwent KOA modeling using the modified Hulth method.Following modeling,the ESWT group received extracorporeal shockwave therapy once weekly for 4 weeks.In the inhibitor group,before in vitro shockwave treatment,0.1 mL of the ERK1/2 signaling pathway inhibitor U0126(100 μmol/mL)was injected into the joint cavity once weekly for a total of 4 weeks.The sham and model groups were immobilized in restraints without additional intervention.Tissue sampling was performed after 4 weeks of intervention.The modified Lequesne MG scale was used to assess behavioral changes before and after intervention in all groups.Radiography was used to evaluate knee joint imaging changes.Hematoxylin-eosin and safranin O-fast green staining were used to examine cartilage histopathology.Chondrocyte ultrastructure and autophagy was observed using transmission electron microscopy.Real-time quantitative PCR was used to measure ERK1/2,ULK1,and Beclin-1 mRNA expression in cartilage tissue across groups.Western blot was used to analyze phosphorylated(P)-ERK1/2,ERK1/2,ULK1,and Beclin-1 protein expression in cartilage tissue.Immunohistochemical staining was used to examine the in situ expression and distribution of P-ERK1/2,ULK1,and Beclin-1 in cartilage tissue.Results Compared with the sham group,rabbits in the model group had higher behavioral scores,marked damage to joint radiographic structures,severe cartilage degeneration,reduced autophagosome numbers within chondrocytes,and significantly lower protein levels of P-ERK1/2 and mRNA and protein levels of the autophagy-related molecules ULK1 and Beclin-1 in cartilage tissue(P＜0.05).Compared with the model group,the ESWT group showed improvements in both behavioral scores and radiographic findings,exhibiting a relatively smooth cartilage surface and superior matrix staining.The number of autophagosomes within chondrocyte increased,and the mRNA and protein expression levels of P-ERK1/2,ULK1,and Beclin-1 were significantly elevated in cartilage tissue(P＜0.05).Compared with the ESWT group,the inhibitor group showed weaker behavioral and imaging improvements,more severe cartilage damage,fewer autophagosomes,and downregulated protein and mRNA expression of the relevant molecules(P＜0.05).Conclusions Extracorporeal shockwave therapy regulates autophagy in rabbit chondrocytes with KOA by modulating the ERK1/2 signaling pathway,thereby exerting a protective effect on articular cartilage and slowing KOA progression.These findings provide experimental evidence for the clinical application of this therapy.