Effect of ebosin on modulating interleukin-1β-induced inflammatory responses in rat fibroblast-like synoviocytes

Abstract

The interleukin-1b-mitogen-activated protein kinase (MAPK) and NF-kB signaling pathways are involved in the pathogenesis of rheumatoid arthritis. Ebosin, a novel exopolysaccharide (EPS), exhibits anti-inflammatory activity in rat collagen-induced arthritis by suppressing the production of tumor necrosis factor-a, interleukin-6 and interleukin-1b. The aim of the present study was to assess the effects of ebosin on NF-kB and MAPK signaling pathways mediated through interleukin-1b in rat fibroblast-like synoviocytes (FLSs). Western blotting showed decreased production of phosphorylated p38, JNK1, JNK2, IKKa, IKKb and IkB in the cytoplasm and NF-kB in the nucleus upon ebosin treatment. The DNA-binding activity of NF-kB in the cell nucleus was also inhibited by ebosin treatment, as demonstrated using an electrophoresis mobility gel shift assay. Analysis of the results of the immunofluorescence assay also showed a reduced amount of NF-kB in the nucleus of cells affected by ebosin. These results provided evidence for the effects of ebosin on both interleukin-1b-mediated MAPK and NF-kB signaling pathways in rat FLSs. In addition, enzyme-linked immunosorbent assay demonstrated that ebosin reduces the levels of matrix metalloproteinases MMP-1 and MMP-3 and the chemokines, interleukin-8 and RANTES. Thus, the results of the present study provide further evidence for understanding the medicinal activity of ebosin at a molecular level, therefore nominating this EPS as a potential therapeutic candidate for the treatment of rheumatic arthritis.

Ebosin Ameliorates Psoriasis-Like Inflammation of Mice via miR-155 Targeting tnfaip3 on IL-17 Pathway

“…It exhibited in vivo inflammatory inhibition on both adjuvant arthritis and type II collagen arthritis rat model. Ebosin effectively reduced inflammation and joint damage through inhibiting proteins expression in MAPK and NF-κB signaling pathways in vitro , followed by production suppression of IL-1, TNFα, MMPs, and CC chemokines ( 25 , 31 ). Excitingly, Ebosin could significantly suppress the production of CXCL-9 in preliminary experiments ( Supplementary Figures S1C, D ), which is a key indicator of psoriasis.…”

“…The cells were cultivated in Minimum Essential Medium with Eagle’s Balanced Salts (MEM-EBSS; Hyclone, Solarbio, Beijing, China) containing 10% fetal bovine serum (FBS; Gibco Life Technologies, Carlsbad, CA, USA), and were incubated at 37°C with 5% CO 2 . Cells were treated with 10 μg/ml lipopolysaccharide (LPS; Beyotime, Shanghai, China) and series concentration of Ebosin for 24 h. Ebosin was prepared as previously described ( 25 ) and was stored at −20°C.…”

“…As with psoriasis, miR-155 has been found to be highly expressed in psoriatic and various autoimmune diseases patients. The level of miR-155 in skin has been demonstrated to have a significantly positive correlation with PASI score and IL-17A content (24). Although several miRNAs have been identified as positive or negative regulators in the regulation of psoriasis, the detailed mechanism needs to be further illustrated.…”

“…Ebosin, a novel exopolysaccharide composed of rhamnose, fucose, arabinose, mannose, xylose, glucose, galactose, and galacturonic acid, was isolated from the supernatant of the fermentation culture of Streptomyces sp. 139 ( 25 ). Previous studies have shown that Ebosin significantly suppresses the development of rat collagen-induced arthritis in vivo ( 26 ), and inhibits IL-1β–induced MAPK and NF-κB signaling pathway in rat fibroblast-like synoviocytes (FLSs) in vitro ( 25 ).…”

“…139 ( 25 ). Previous studies have shown that Ebosin significantly suppresses the development of rat collagen-induced arthritis in vivo ( 26 ), and inhibits IL-1β–induced MAPK and NF-κB signaling pathway in rat fibroblast-like synoviocytes (FLSs) in vitro ( 25 ). Interestingly, we found that Ebosin could reduce IFNγ-induced CXCL-9 level in HaCaT cells, which is a key evaluated indicator for psoriasis.…”