Wnt/ß-catenin signaling pathway promotes abnormal activation of fibroblast-like synoviocytes and angiogenesis in rheumatoid arthritis and the intervention of Er Miao San.

BACKGROUND: Er Miao San (EMS) is an important herbal formula and a representative prescription for the treatment of the downwards flow of damp-heat syndrome. Clinical practice has proven that EMS can effectively treat rheumatoid arthritis (RA). Previous studies have demonstrated that EMS regulates the functions of T cells and dendritic cells and affects the polarization of macrophages. However, it is not clear whether the inhibitory effect of EMS on RA is related to the regulation of abnormal synovial activation and angiogenesis. PURPOSE: The aim of this study was to elucidate the effect and potential mechanisms of EMS on the abnormal activation and angiogenesis of fibroblast-like synoviocytes (FLSs) in RA. METHODS: The effect of EMS on rats with adjuvant arthritis (AA) and MH7A cells was examined by X-ray, haematoxylin-eosin (HE) staining, immunohistochemistry (IHC), ELISA and western blotting. Angiogenesis in AA rats was measured by a small animal ultrasound imaging system, immunofluorescence (IF) analysis and ELISA. An exchange between MH7A cells and HUVECs was induced using conditioned media that mimicked the microenvironment in vivo. CCK-8, western blotting, and scratch healing and Transwell migration assays were used to evaluate the effect of EMS on the Wnt/ß-catenin signaling pathway and angiogenesis in the inflammatory microenvironment of RA. RESULTS: Our results showed that EMS had a protective effect on AA rats. On the one hand, there was a decrease in paw swelling, the arthritis index, organ indices and proinflammatory factor levels, as well as relief of joint damage. On the other hand, blood flow, the number of immature blood vessels and proangiogenic factors were decreased. Furthermore, EMS reduced the expression of the Wnt/ß-catenin signaling pathway in the synovial tissue of AA rats and MH7A cells. In the inflammatory microenvonrment of RA, the results were consistent. CONCLUSION: This study demonstrated that EMS could protect against RA by inhibiting the abnormal activation and angiogenesis of FLSs, and the mechanism may be related to inhibiting the activation of the Wnt/ß-catenin signaling pathway.

Exploring the effect of Er miao San-containing serum on macrophage polarization through miR-33/NLRP3 pathway.

HEADINGS ETHNOPHARMACOLOGICAL RELEVANCE: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. Er miao San (EMS) has been shown to have good anti-inflammatory effects and is widely used in the clinical treatment of RA. However, the exact mechanism is not completely understood. AIM OF THE STUDY: The aim of this study was to explore that EMS-containing serum affects M1/M2 polarization of macrophages and may be mediated through the microRNA (miRNA)-33/NLRP3 pathway, thereby elucidating the molecular mechanism of EMS treatment of RA. MATERIALS AND METHODS: We screened for safe concentrations of EMS-containing serum by using CCK-8 measurement. RAW264.7 cells were cultured with lipopolysaccharide (LPS) (100 ng/mL) and interferon-γ (20 ng/mL) for 24 h to induce M1-type macrophages. Adenosine triphosphate (ATP) (5 mM) was added in the last 30 min to activate NLRP3. The content of miR-33 was detected by RT‒qPCR after transfection of the miRNA-33 mimic. The protein expression levels of NLRP3, ASC, caspase-1, Inducible Nitric Oxide Synthase (iNOS) and Arginase-1 (Arg-1) were detected by Western blot. The contents of IL-1ß, IL-10, TNF-α, TGF-ß and IL-18 in serum and cell supernatant were determined by ELISA. The fluorescence intensity of CD86 and CD206 was detected by immunofluorescence. RESULTS: The results showed that EMS-containing serum promoted the protein expression level of Arg-1 and the secretion levels of TGF-ß and IL-10, inhibited the levels of iNOS, IL-1ß and TNF-α, and regulated the balance of pro-inflammatory factors and anti-inflammatory factors. RT‒qPCR results showed that EMS-containing serum could reduce the level of miRNA-33. EMS-containing serum could reduce the expression of NLRP3 inflammasome-related proteins and downregulate the expression levels of IL-1ß and IL-18. These results suggest that EMS exerts its effect on macrophage polarization through the miRNA-33/NLRP3 pathway. CONCLUSION: EMS-containing serum inhibits the activation of the NLRP3 inflammasome by downregulating miRNA-33, thus preventing the polarization of M1-type macrophages.