基于TGF-β1/Smad3信号通路探讨推拿按法抑制激痛点纤维化的作用机制OA

Objective To investigate whether Tuina alleviates fibrotic symptoms in myofascial trigger points(MTrPs)by regulating transforming growth factor(TGF)-β1/Smad3 signaling pathway,thereby deactivating these points. Methods This study comprised two experimental phases.In phase 1,27 specific pathogen-free(SPF)grade female Sprague-Dawley(SD)rats were randomized into three groups:con-trol 1,model 1,and Tuina 1 groups.Model 1 and Tuina 1 groups underwent an 8-week MTrPs modeling protocol involving blunt impact and eccentric exercise.After successful modeling,rats in Tuina 1 group received manual pressing on nodules or cord-like taut bands on the me-dial aspect of the left hindlimb.Pain sensitivity and tissue stiffness were evaluated via pres-sure pain threshold(PPT)and soft tissue tension(STT).Muscle histopathology and fibrosis were observed using hematoxylin and eosin(HE)and Masson staining.Inflammatory factors in muscle were measured by enzyme-linked immunosorbent assay(ELISA),while im-munofluorescence(IF)and Western blot(WB)were used to detect the expression levels of α-smooth muscle actin(α-SMA),collagen Ⅲ,and TGF-β1.In phase 2,45 SPF female SD rats were randomized into five groups:control 2,model 2,Tuina 2,TGF-β1 inhibitor(TI),and Tuina+TGF-β1 agonist(Tuina+TA)groups.All groups except control 2 underwent standard-ized MTrPs modeling.Rats in Tuina 2 group received consistent pressing manipulation.TI group received intraperitoneal injections of oxymatrine,while Tuina+TA group received in-traperitoneal injections of SRI-011381 hydrochloride followed by the same pressing protocol as Tuina 2 group.WB was used to detect the expression of collagen I,collagen III,TGF-β1,and phosphorylated-Smad3(p-Smad3)/Smad3. Results In phase 1,Tuina significantly improved PPT and STT in MTrPs of rats(P<0.01),re-versed pathological damages including disorganized muscle fiber arrangement,abnormal myocyte morphology,and exacerbated fibrosis.In addition,in MTrPs of rats in model 1 group,expression levels of nuclear factor kappa-light-chain-enhancer of activated B cells(NF-κB),interleukin(IL)-1β,IL-6,tumor necrosis factor(TNF)-α,and fibrosis markers(α-SMA,collagen I,and collagen III)were upregulated,and all exhibited a significant downward trend after Tuina intervention(P<0.05 or P<0.01).This indicates that the therapeutic effects of Tuina are directly associated with reduced local inflammation and fibrosis in MTrPs.In phase 2,compared with model 2 group,rats in TI and Tuina 2 groups had decreased expression levels of TGF-β1 and p-Smad3/Smad3 in MTrPs,alongside reduced levels of in-flammatory factors(IL-1β,IL-6,NF-κB,and TNF-α)and fibrosis markers(α-SMA,collagen I,and collagen III)(P<0.05 or P<0.01).When co-administered with TGF-β1 agonist,the thera-peutic effects of Tuina were significantly attenuated,with rebounded TGF-β1 expression and p-Smad3/Smad3 in local MTrPs,and fibrosis and inflammatory responses were re-exacerbat-ed(P<0.05 or P<0.01). Conclusion Tuina can effectively reduce inflammatory responses and fibrosis in MTrPs tis-sue,and its mechanism is closely related to the inhibition of the TGF-β1/Smad3 signaling pathway,which plays a critical role in Tuina-mediated regulation of MTrPs fibrosis.