[Medicinal cake-separated moxibustion inhibits ectopic endometrium remodeling by regulating TGF-β/Smad signaling in rats with endometriosis]

OBJECTIVES: To investigate the mechanism of medicinal cake-separated moxibustion in inhibiting the adhesion, invasion and angiogenesis of ectopic endometriotic tissues in endometriosis (EMs) rats through transforming growth factor-β1 (TGF-β)/Sma and Mad related proteins (Smad) signaling pathway. METHODS: Forty-eight female SD rats were randomly divided into blank control, model, medication (gestrinone), and medicinal cake-separated moxibustion(moxibustion) groups (n=12 in each group). The model of EMs was established by autologous transplantation method. The rats in the blank control and model groups were treated with normal saline via gavage, and those of the medication group were treated by intragastric gavage of gestrinone (0.25 mg/kg), once daily for 2 weeks. For rats of the moxibustion group, medicinal cake-separated moxibustion was applied to "Guanyuan" (CV4), "Qihai" (CV6) and "Zigong"(EX-CA1) for 30 min, once a day for 14 consecutive days. At the end of the treatment, the rats in the model and two treatment groups received intraperitoneal injection of oxytocin for inducing an experimental dysmenorrhea, and the number of writhing in 20 min due to dysmenorrhea was recorded, once daily for 7 consecutive days, and the volume of ectopic endometrium tissue was measured by using a vernier caliper. H.E. staining was used to observe histopathological changes of the ectopic endometrium tissue. The expression levels of TGF-β1, Smad2, Smad3, urokinase-type plasminogen activator (uPA), vascular endothelial growth factor A (VEGFA), matrix metalloproteinase (MMP) 9, and MMP2 were detected by immunohistochemistry and Western blot, separately. RESULTS: Compared with the blank control group, the writhing score and incidence, EMs volume, average optical density values of TGF-β1, Smad2, Smad3, uPA, VEGFA, and MMP9, and the protein expression levels of MMP9, MMP2, TGF-β1, Smad2, Smad3, uPA and VEGFA were significantly up-regulated (P<0.01, P<0.05) in the model group. Compared with the model group, the writhing score and incidence, EMs volume, immunoactivity of TGF-β1, Smad2, Smad3, uPA, VEGFA and MMP9, and the protein expression levels of MMP9, MMP2, TGF-β1, Smad2, uPA and VEGFA were significantly down-regulated (P<0.05, P<0.01) in both medication and moxibustion groups. The effect of moxibustion was apparently superior to that of medication in down-regulating the immunoactivity of Smad2 (P<0.05), and inferior to that of medication in down-regulating the immunoactivity of MMP9 and VEGFA, and protein expression levels of Smad3, MMP9, MMP2 and uPA (P<0.05). H.E. staining showed discontinuous epithelial tissue structure accompanied by obvious angiogenesis in the ectopic endometrium of the model group, and relatively loose arrangement of the epithelial nuclei of the lesions with vacuolar degeneration, and increased number of glands in both medication and moxibustion groups. CONCLUSIONS: Medicinal cake-separated moxibustion can relieve dysmenorrhea and inhibit the development of ectopic endometrium in EMs rats, which may be related to its functions in down-regulating the expressions of TGF-β/Smad signaling related factors, and in inhibiting the adhesion, invasion and angiogenesis of ectopic endometrium tissue.