The Effects Of Sinomenine On TLR4/MyD88/NF-?B Pathway In Mice Synovium With Collagen-induced Arthritis

Objective:Collagen-induced arthritis(CIA) mice model were induced, and then by observing the effect of SIN on joint swelling, synovial pathology, the level of serum TNF-?, IL-17,protein and mRNA expression of toll-like receptor 4(TLR4), myeloid differentiation factor 88(MyD88), nuclear factor-?B(NF-?B) in mice synovium to explore the mechanism of SIN on RA.Methods:1. Grouping and Administration: Six weeks DBA/1 mice were randomly divided into three groups: the normal group(n=10), the CIA group(n=10), the SIN group(n=10).Except for the normal group, the other mice were respectively given a primary and secondary immunization with ? collagen emulsion on the base of the tail to induce CIA model. The day of the primary immunization was referred to d 0. The mice in the SIN group were given SIN intragastrically once a day from d 28; as a control, those in the normal group and CIA group were given saline. All mice were treated for 20 days continuously. Arthritis index(AI) scores were measured and recorded based on joint swelling of each mice from d 21.2. Index Detection: All mice were sacrificed after d 48, synovial tissues and serum samples were collection. The change of synovial pathology were observed by hematoxylin and eosin(HE) staining assay; the levels of serum TNF-?, IL-17 were determined by ELISA method; the protein expression of TLR4, MyD88, NF-?B in synovial tissues were measured by western blot analysis; the mRNA expression of TLR4, MyD88, NF-?B in synovial tissues were determined by reverse transcription-polymerase chain reaction(RT-PCR) analysis.Result:1. The effect of SIN on joint swelling in mice: the AI scores of the CIA group were significantly increased and different from the normal group in the periods from d24 to d 48 after primary immunization; in the periods from d 24 to d 36 after primary immunization, the AI scores of the SIN group has no significantly different compared with the CIA group; compared with the CIA group, the AI scores of the SIN group were reduced significantly in the periods from d 39 to d 48.2. The effects of SIN on histopathological changes in mice: compared with the normal group, the CIA group has significantly increased in synovial inflammatory cells infiltration and synovial cell proliferation; compared with the CIA group, synovial inflammatory cells infiltration and synovial cell proliferation in SIN group were significantly reduced.3. The effects of SIN on the levels of TNF-?, IL-17 in serum: compared with the normal group, the levels of serum TNF-?, IL-17 in the CIA group were significantly increased and different; the levels of serum TNF-?, IL-17 in SIN group were reduced significantly when compared with the CIA group.4. The effects of SIN on protein expression of TLR4, MyD88 and NF-?B in synovium: the protein expression of TLR4, MyD88 and NF-?B were significantly upregulated in the CIA group compared with the normal group; however, the protein expression of TLR4, MyD88 and NF-?B in the SIN group was downregulated compared with the CIA group.5. The effects of SIN on mRNA expression of TLR4, MyD88 and NF-?B in synovium: compared with the normal group, the mRNA expression of TLR4, MyD88 and NF-?B in the CIA group were significantly upregulated; the mRNA expression of TLR4, MyD88 and NF-?B in the SIN group were downregulated compared with the CIA group.Conclusion:SIN improved the paw swelling and reduced the AI scores in CIA mice, also synovial inflammation cells infiltration and the serum levels of TNF-?, IL-17,meanwhile downregulated the protein and mRNA expression of TLR4, MyD88 and NF-?B in synovium; the therapeutic effect of SIN on CIA mice might be associated withsuppressing TLR4/MyD88/NF-?B signaling pathway in synovium.