Effects of moxibustion on p53， SLC7A11， and GPX4 expression in synovial tissues of rats with adjuvant arthritis

Abstract

To observe the effects of moxibustion on p53, cystine/glutamate antiporter solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4) in synovial tissues of rats with adjuvant arthritis (AA), so as to explore the mechanism of moxibustion in alleviating rheumatoid arthritis. Eighty rats were randomly divided into normal, model, moxibustion, and medication groups (n=20 in each group). The AA model was established by exposure to wind, cold, and damp environmental factors combined with injection of complete Freund's adjuvant. Rats in the moxibustion group received suspended moxibustion at "Shenshu" (BL23) and "Zusanli" (ST36) alternately, while those in the medication group were treated with tripterygium glycoside tablet suspension (8 mg/kg) by gavage, once a day, for 15 successive days. The pathological change in synovial tissue of rat right knee joint was observed by HE staining. The protein and mRNA expression levels of p53, SLC7A11, and GPX4 in the synovial tissue were detected by Western blot and quantitative real-time PCR, respectively. The se-rum glutathione (GSH) and reactive oxygen species (ROS) contents were measured by colorimetry and fluorescence probe me-thod. Compared with the normal group, the model group exhibited synovial hyperplasia of the right knee joint, massive inflammatory cell infiltration, up-regulated mRNA and protein expression of p53 in synovial tissue, elevated serum ROS content (P<0.01), down-regulated mRNA and protein expression of SLC7A11 and GPX4 in synovial tissue, and lowered serum GSH content (P<0.01). Comparison with the model group showed that the synovial injuries in the moxibustion and medication groups were obviously alleviated. The mRNA and protein expression levels of p53 in the synovial tissues and the serum ROS content declined significantly (P<0.01), while the mRNA and protein expression of SLC7A11 and GPX4 in the synovial tissues and the se-rum GSH content increased (P<0.01). There was no significant difference in histopathological change of synovial tissue between the moxibustion group and medication group. However, the p53 protein expression in the synovial tissue and the level of serum ROS were significantly higher in the medication group than in the moxibustion group (P<0.05), while the GPX4 protein expression and serum GSH content were down-regulated (P<0.05). Moxibustion improves the inflammatory response in synovial tissue of AA model rats, which may be closely related to its regulation of the expression of ferroptosis-related factors.