To observe the effect of moxibustion intervention on the expression of toll-like receptor-4 (TLR 4), myeloid differentiation factor 88(MyD 88), and nuclear factor kappa B p 65 (NF-κB p 65) genes of knee-joint synovial cells in rheumatoid arthritis (RA) rats, so as to explore its molecular mechanism underlying improving RA.
Forty SD rats were randomly divided into normal control, RA model, moxibustion and medication groups (n = 10). The RA model was duplicated by raising the rats in a windy, cold and wet environment, followed by injecting Freund's complete adjuvant (0. 15 mL) into the rat's foot. Moxibustion was applied to "Shenshu" (BL 23) and "Zusanli" (ST 36) for 20 min, once daily for 15 days. Rats of the medication group were treated by intragastric administration of tripterygium wilfordii (8. 75 mL/kg), once daily for 15 days. Pathological changes of the synovial tissues were detected by H. E. stain, the contents of serum TNF-α and IL-1 detected by radioimmunoassay, and the expression levels of TLR 4 mRNA, MyD 88 mRNA and TRAF-6 mRNA of synovial tissue were analyzed by real time-PCR, and the NF-κB p 65 immunoactivity was assayed by immunohistochemistry.
In comparison with the normal control group, the synovial tissue of the knee-joint was impaired remarkably and infiltrated by numerous inflammatory cells, and the synovial surface got thickening because of hyperplasia in the model group. Following moxibustion and medication, these situations such as synovial infiltration of inflammatory, synovial cell proliferation were alleviated. The serum TNF-α and IL-1 contents and synovial TLR 4 mRNA, MyD 88 mRNA, TRAF-6 mRNA and NF-κB p 65 expression levels were remarkably higher in the model group than in the control group(P<0. 01). After moxibustion and medication, the contents of serum TNF-α and IL-1, the expression levels of TLR 4 mRNA, MyD 88 mRNA, TRAF-6 mRNA and NF-κB p 65 were significantly down-regulated(P<0. 01, P<0. 05).
Moxibustion intervention can improve pathological changes of the knee-joint synovial membrane tissue in RA rats, which may be related with its effect in inhibiting abnormal activation of TLR 4-MyD 88-NF-κB pathway in synovial tissue.