Melatonin attenuates TNF-α and IL-1β expression in synovial fibroblasts and diminishes cartilage degradation: Implications for the treatment of rheumatoid arthritis.
The hormone melatonin has many properties, including antioxidant, anti-inflammatory, and immunomodulatory effects. Melatonin has been demonstrated to be beneficial in several inflammatory autoimmune diseases, but its effects in rheumatoid arthritis (RA) remain controversial. We sought to determine how melatonin regulates inflammation in RA. We found that melatonin dose-dependently inhibits tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β expression through the PI3K/AKT, ERK, and NF-κB signaling pathways. We also identified that melatonin inhibits TNF-α and IL-1β production by upregulating miR-3150a-3p expression. Synovial tissue specimens from RA patients and culture of human rheumatoid fibroblast-like synoviocytes confirmed that the MT1 receptor is needed for the anti-inflammatory activities of melatonin. Importantly, melatonin also significantly reduced paw swelling, cartilage degradation, and bone erosion in the collagen-induced arthritis mouse model. Our results indicate that melatonin ameliorates RA by inhibiting TNF-α and IL-1β production through downregulation of the PI3K/AKT, ERK, NF-κB signaling pathways, as well as miR-3150a-3p overexpression. The role of melatonin as an adjuvant treatment in patients with RA deserves further clinical studies.
Huang CC
，Chiou CH
，Liu SC
，Hu SL
，Su CM
，Tsai CH
，Tang CH
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Inhibition of hyaluronan synthesis reduced inflammatory response in mouse synovial fibroblasts subjected to collagen-induced arthritis.
Hyaluronan (HA) fragments are able to induce inflammation by stimulating both CD44 and toll-like receptor 4 (TLR-4). CD44 and TLR-4 activation stimulates the liberation of NF-kB and pro-inflammatory cytokine responses. The aim of this study was to investigate the effects of hyaluronidase (HYAL) treatment, which depolymerises HA into small fragments, and of the addition of specific hyaluronan synthases-1, 2, and 3 small interference RNA (HASs siRNA), which silence HASs activity, on normal mouse synovial fibroblasts (NSF) and on rheumatoid arthritis synovial fibroblasts (RASF) obtained from mice subjected to collagen induced arthritis (CIA). The addition of HYAL to NSF and/or RASF significantly increased the TLR-4, CD44 and NF-kB activity, as well as the pro-inflammatory cytokines, interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-33 (IL-33) in both groups, but to a greater extent in RASF. The addition to NSF and/or RASF of the HASs siRNA, which block HASs activity and therefore the availability of HA substrate for HYAL, was able to reduce HYAL effects in both NSF and RASF. Finally, the HA evaluation confirmed the increment of HA at low molecular weight after HYAL treatment.
Campo GM
，Avenoso A
，D'Ascola A
，Prestipino V
，Scuruchi M
，Nastasi G
，Calatroni A
，Campo S
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Suppression of hyaluronan synthesis alleviates inflammatory responses in murine arthritis and in human rheumatoid synovial fibroblasts.
To clarify the roles of hyaluronan (HA) in joint inflammation and the process of joint destruction, using 4-methylumbelliferone (4-MU), an inhibitor of HA synthesis, in a mouse model of collagen-induced arthritis (CIA) and in a monolayer culture of fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis.
DAB/1J mice were immunized with type II collagen. The effects of 4-MU were evaluated by the physiologic arthritis score, paw swelling, the histologic arthritis score, and expression of matrix metalloproteinase 3 (MMP-3) and MMP-13 in chondrocytes and synovial tissue. In vitro, the effect of 4-MU on messenger RNA and protein expression of MMP-1 and MMP-3 was determined. The effects of 4-MU on HA deposition and on serum/medium concentrations of HA were analyzed using biotinylated HA binding protein staining and an HA binding assay, respectively.
Treatment with 4-MU in mice with CIA dramatically decreased the severity of arthritis (based on the arthritis score), paw thickness, and histopathologic changes. MMP-3 and MMP-13 expression in chondrocytes and synovial cells was significantly inhibited by 4-MU in vivo. Treatment with 4-MU also inhibited MMP-1 and MMP-3 expression in tumor necrosis factor α-stimulated FLS, in a dose-dependent manner. The 4-MU-induced decreases in the serum HA concentration in mice with CIA and in "medium" and "pericellular" HA concentrations in cultured FLS support the contention that the inhibitory mechanism of 4-MU is mediated by HA suppression.
Reduced disease activity induced by 4-MU in mice with CIA revealed HA to be a crucial regulator in the course of arthritis. Therefore, 4-MU is a potential therapeutic agent in arthritis, and its inhibitory mechanism is possibly mediated by suppression of HA synthesis.
Yoshioka Y
，Kozawa E
，Urakawa H
，Arai E
，Futamura N
，Zhuo L
，Kimata K
，Ishiguro N
，Nishida Y
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Guizhi-Shaoyao-Zhimu decoction possesses anti-arthritic effects on type II collagen-induced arthritis in rats via suppression of inflammatory reactions, inhibition of invasion & migration and induction of apoptosis in synovial fibroblasts.
Rheumatoid arthritis (RA) is a known intractable chronic inflammatory disease of synovial joints characterized by hyperplasia and consecutive inflammation with a high prevalence.Guizhi-Shaoyao-Zhimu (GSZD) is the first choice for clinical treatment of RA in Chinese traditional medicine. This study is aimed to explore the possible pharmacological mechanisms of anti-arthritic effect of GSZD.
Type II collagen-induced arthritis (CIA) rat model was used to study the anti-arthritic activity of GSZDin vivo, and toe swelling & arthritis score, serum levels of cytokines, and pathological examinations were carried out. In vitro, TNF-α induced MH7A cells were used to study the possible mechanisms of GSZD. The anti-proliferative effects of GSZD were determined by MMT assay, and pro-apoptotic activity of GSZD in MH7A cells was determined by flow cytometry analysis & DAPI staining. Furthermore, the adhesive and invasive abilities of MH7A cells were determined using cell adhesion and transwell assays. MMPs levels were determined by ELISA assays, and mRNA expressions of Caspase-3, -9, Bax, SOCS1, Bcl-2, JAK2, STAT-3 and -5 were determined using qRT-PCR analysis. Besides, the major chemical components in GSZD were analyzed by HPLC-QqQ-MS analysis.
Our results showed GSZD reduced the toe swelling & arthritis score, and serum levels of TNF-α, IL-1β, IL-6 & IL-17a in CIA rats; pathological examination results indicated GSZD improved ankle joint injury in CIA rats.In vitro, GSZD showed significant anti-proliferative and pro-apoptotic effects on TNF-α stimulated MH7A cells. After GSZD treatment, the adhesive and invasive abilities of MH7A cells were reduced, and secretions of MMPs, IL-6 and IL-8 were also reduced. GSZD decreased the releases of TNF-α and IL-1β in LPS stimulated RAW 264.7 cells. Further studies showed GSZD up-regulated mRNA expressions of Caspase-3, -9, Bax, and SOCS1, whereas down-regulated mRNA expressions of Bcl-2, JAK2, STAT3 and STAT5. Besides, 13 major chemical components were identified in GSZD extracts through HPLC-QqQ-MS analysis.
Our results suggested GSZD possesses an anti-rheumatic effect on CIA rats, and the possible mechanism is related to inhibiting inflammatory response, inhibiting invasion and migration of synovial fibroblasts, and inducing apoptosis in synovial fibroblasts.
Zhang Q
，Peng W
，Wei S
，Wei D
，Li R
，Liu J
，Peng L
，Yang S
，Gao Y
，Wu C
，Pu X
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ResearchGate
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