[Effects of Sidaxue, a Miao ethnomedicine recipe, on apoptosis and pyrolysis of human fibroblast-like synovial cells in rheumatoid arthritis]

[The Miao medicine Sidaxue alleviates rheumatoid arthritis in rats possibly by downregulating matrix metalloproteinases]

OBJECTIVE

To explore the inhibitory effect of Sidaxue, a traditional Miao herbal medicine formula, on articular bone and cartilage destruction and synovial neovascularization in rats with collagen-induced arthritis (CIA).

METHODS

In a SD rat model of CIA, we tested the effects of daily gavage of Sidaxue at low, moderate and high doses (10, 20, and 40 g/kg, respectively) for 21 days, with Tripterygium glycosides (GTW) as the positive control, on swelling in the hind limb plantar regions by arthritis index scoring. Pathologies in joint synovial membrane of the rats were observed with HE staining, and serum TNF-α and IL-1β levels were detected with ELISA. The expressions of NF-κB p65, matrix metalloproteinase 1 (MMP1), MMP2 and MMP9 at the mRNA and protein levels in the synovial tissues were detected using real-time PCR and Western blotting. Network pharmacology analysis was conducted to identify the important target proteins in the pathways correlated with the therapeutic effects of topical Sidaxue treatment for RA, and the core target proteins were screened by topological analysis.

RESULTS

Treatment with GTW and Sidaxue at the 3 doses all significantly alleviated plantar swelling, lowered arthritis index scores, improved cartilage and bone damage and reduced neovascularization in CIA rats (P<0.05), and the effects of Sidaxue showed a dose dependence. Both GTW and Sidaxue treatments significantly lowered TNF-α, IL-1β, NF-κB p65, MMP1, MMP2, and MMP9 mRNA and protein expressions in the synovial tissues of CIA rats (P<0.05). Network pharmacological analysis identified MMPs as the core proteins associated with topical Sidaxue treatment of RA.

CONCLUSION

Sidaxue alleviates articular bone and cartilage damages and reduces synovial neovascularization in CIA rats possibly by downregulating MMPs via the TNF-α/IL-1β/NF-κB-MMP1, 2, 9 signaling pathway, and MMPs probably plays a key role in mediating the effect of Sidaxue though the therapeutic pathways other than oral administration.

[Effects of serum from Xinfeng capsule-treated rats on lipopolysaccharide-induced pyroptosis in rheumatoid arthritis synovial fibroblasts]

OBJECTIVE

To observe the effect of serum from rats treated with Xinfeng Capsule (XFC) on lipopolysaccharide (LPS)-induced pyroptosis of rheumatoid arthritis synovial fibroblasts (RA-FLS) and explore the possible mechanism.

METHODS

Twenty SD rats were divided into blank control group and XFC group. The rats in XFC group was given 0.324 mg/g XFC by gavage for 7 days to prepare the drug-containing serum. CCK-8 assay was used to determine the optimal concentration and duration of the serum for cell treatment. The effect of the drug-containing serum or MCC950 on viability of RA-FLS stimulated with 5 μg/mL LPS was assessed with CCK-8 assay, and pyroptosis of the cells was observed using electron microscope; the levels of IL-1β and IL-18 in the cell culture supernatant were detected by ELISA, and the protein and mRNA expressions of NLRP3, caspase-1 and GSDMD were detected using Western blotting and qRT-PCR.

RESULTS

The optimal concentration and duration of XFC for RA-FLS treatment were 20% and 24 h, respectively. Compared with the blank control cells, the cells with LPS stimulation showed significantly increased cell viability (P<0.05) and electron microscopy revealed a large number of vesicles in the cells with formation of membrane pores, cell membrane rupture, and leakage of cell contents. LPS stimulation significantly increased IL-1β and IL-18 levels and expressions of NLRP3, GSDMD, and caspase-1 in the cells (P<0.05 or 0.01). Treatment with the drug-containing serum or MCC950 significantly decreased the viability of LPS-stimulated RA-FLS (P<0.01), reduced cell pyroptosis, and lowered the concentrations of IL-1β and IL-18 and expressions of NLRP3, GSDMD, and caspase-1 (P<0.05 or 0.01).

CONCLUSION

XFC alleviates local inflammatory response of joints in RA possibly by inhibiting pyroptosis of the FLS through inhibition of the NLRP3/GSDMD pathway, which results in reduced secretion of inflammatory cytokines.

[Sidaxue, a traditional Guizhou Miao herbal medicine formula, reduces necroptosis and synovial vascular proliferation in rats with collagen-induced arthritis by inhibiting the RIPK1/RIPK3/MLKL pathway]

OBJECTIVE

To explore the inhibitory effect of Sidaxue (SX), a traditional Guizhou Miao herbal medicine formula, on necrotic apoptosis and synovial angiogenesis in rats with collagen-induced arthritis (CIA) and the role of the RIPK1/RIPK3/MLKL pathway in mediating this effect.

METHODS

Forty-two SD rats were randomized into 6 groups (n=7), including a normal control group, a CIA model group, 3 SX treatment groups at low (10 g/kg), moderate (20 g/kg) and high (40 g/kg) doses, and a GTW treatment group. CIA rat models were established by subcutaneous injections of bovine type II collagen, and the treatments were administered daily by gavage for 21 days. The rats were observed for swelling of the hind limb joints, which was rated using the arthritis index (AI) score on a weekly basis. Serum levels of TNF-α, IL-1β and IL-17 in the rats were detected using ELISA, and the pathological changes in the synovium were observed with HE staining. Real-time PCR was performed to detect the mRNA expression levels of VEGF, MMP-9, Ang-1, RIPK1, RIPK3, and caspase-8 in the synovial tissues, and the protein expressions of VEGF, MMP9, Ang-1, Stat-3, RIPK1, RIPK3, MLKLl, p-MLKL and caspase-8 were detected using Western blotting.

RESULTS

Compared with those in CIA model group, the rats receiving treatment with GTW and SX showed milder swelling of the hind limb joints with significantly lower AI scores (P < 0.05). In CIA model group, a large number of inflammatory cells were observed in the synovium with obvious damages of the tissue structure. In the drug treatment groups, inflammatory cell infiltration, synovial angiogenesis and synovial hyperplasia were alleviated, and the therapeutic effects were obviously enhanced as SX dose increased. Compared with those in the model group, the rats treated with GTW and high-dose SX showed significantly decreased serum levels of IL-1β, IL-17 and TNF-α (P < 0.05), lower mRNA and protein expressions of RIPK1, RIPK3, VEGF, Ang-1, and MMP9 (P < 0.05), higher expressions of caspase-8 (P < 0.01), and obviously lowered expression of Stat-3 protein and phosphorylation level of MLKL (P < 0.05).

CONCLUSION

SX can improve synovial angiogenesis in CIA rats possibly by inhibiting the activation of RIP1/RIP3/MLKL signaling pathway and down-regulating the expression of the vascular growth factors VEGF, Ang-1, MMP9, and Stat-3.

[Triptolide inhibits inflammatory response and migration of fibroblast like synovial cells in rheumatoid arthritis through the circRNA 0003353/JAK2/STAT3 signaling pathway]

OBJECTIVE

To investigate the effect of triptolide (TPL) on inflammatory response and migration of fibroblast like synovial cells (FLS) in rheumatoid arthritis (RA-FLS) and the mechanism of circular noncoding RNA (circRNA) 0003353 for mediating this effect.

METHODS

We collected peripheral blood mononuclear cells (PBMCs) and serum samples from 50 hospitalized RA patients and 30 healthy individuals for detecting the expression of circRNA 0003353, immune and inflammatory indexes (ESR, CRP, RF, anti-CCP, IgA, IgG, IgM, C3, and C4) and DAS28 score. Cultured RA-FLS was treated with 10 ng/mL TPL and transfected with a circRNA 0003353 overexpression plasmid, and cell counting kit-8 (CCK-8) assay and Transwell assay were used to detect the changes in the viability and migration of the cells. Enzyme-linked immunosorbent assay (ELISA) was used to examine the cytokines IL-4, IL-6, and IL-17, and real-time fluorescence quantitative PCR (RT-qPCR) was performed to detect the expression of circRNA 003353; Western blotting was used to detect the expressions of p-JAK2, pSTAT3, JAK2 and STAT3 proteins in the treated cells.

RESULTS

The expression of circRNA 0003353 was significantly increased in PBMCs from RA patients and showed a good performance in assisting the diagnosis of RA (AUC=90.5%, P < 0.001, 95% CI: 0.83-0.98). CircRNA 0003353 expression was positively correlated with ESR, RF and DAS28 (P < 0.05). Treatment with TPL significantly decreased the expression of circRNA 0003353, suppressed the viability and migration ability, decreased the expressions of IL-6 and IL-17, and increased the expression IL-4 in cultured RA-FLS in a time-dependent manner (P < 0.01). TNF-α stimulation of RA-FLS significantly increased the ratios of p-JAK2/JAK2 and p-STAT3/STAT3, which were obviously lowered by TPL treatment (P < 0.01). TPL-treated RA-FLS overexpressing circRNA 0003353 showed significantly increased cell viability and migration ability with decreased IL-4 expression and increased IL-6 and IL-17 expressions and ratios of p-JAK2/ JAK2 and p-STAT3/STAT3 (P < 0.01).

CONCLUSION

The expression of circRNA 0003353 is increased in PBMCs in RA patients and in RA-FLS. TPL treatment can regulate JAK2/STAT3 signal pathway and inhibit the inflammatory response and migration of RA-FLS through circRNA 0003353.