Combinatmarion treatment with Lactobacillus acidophilus LA-1, vitamin B, and curcumin ameliorates the progression of osteoarthritis by inhibiting the pro-inflammatory mediators.

Disease-modifying osteoarthritis (OA) therapy is not yet available. Several adjuvant therapies have demonstrated promising results in the treatment of OA. The present study aimed to investigate the therapeutic effects and underlying mechanisms of a combination of Lactobacillus acidophilus, vitamin B, and curcumin in the treatment of OA. Monosodium iodoacetate (MIA)-induced arthritis of the knee joint in rat was used as an animal model of human OA. The combination of L. acidophilus LA-1, vitamin B, and curcumin or a saline solution was given orally. Pain was measured according to the paw withdrawal latency, and paw withdrawal threshold. Cartilage destruction was analyzed using histomorphological techniques and the Mankin scoring system. Protein expression in the joint was examined using immunohistochemistry. The effects of the combination of L. acidophilus LA-1, vitamin B, and curcumin on mRNA levels in chondrocytes stimulated with interleukin (IL)-1ß were analyzed using real-time polymerase chain reaction. The combination of L. acidophilus, vitamin B, and curcumin effectively downregulated Th17 cells and the related cytokine IL-17, thereby maintained the Treg population, and increased the expression of the Treg-related cytokine IL-10 in human peripheral blood mononuclear cells. The OA animal model exhibited reduced pain and preservation of cartilage in response to the combination treatment. The expression levels of pro-inflammatory cytokines and the catabolic, matrix metalloproteinase-13 (MMP-13), were decreased, whereas the expression of the anabolic tissue inhibitors of metalloproteinases (TIMPs) were upregulated in response to the drug combination. The combination of L. acidophilus, vitamin B, and curcumin was beneficial in OA treatment, controlling the inflammatory response via regulation of the Th17/Treg population and reducing the expression of pro-inflammatory cytokines in human peripheral blood mononuclear cells. The combination treatment also preserved cartilage, suppressed osteoclastogenesis, and regulated the anabolic/catabolic imbalance. These findings indicate the therapeutic potential of combination use of L. acidophilus, vitamin B, and curcumin in patients with OA.

YinYang1 deficiency ameliorates joint inflammation in a murine model of rheumatoid arthritis by modulating Th17 cell activation.

Yin Yang 1 (YY1) is a ubiquitously expressed transcription factor that functions in cooperation with various cofactors to regulate gene expression. In the immune system, YY1 enhances cytokine production and T helper (Th) 2 effector cell differentiation, resulting in the activation of inflammation. However, no studies have reported the role of YY1 in Th17 cell regulation, which is implicated in rheumatoid arthritis (RA). We investigated the expression of YY1 in Th17 cells in vitro and revealed increased levels of YY1 mRNA and protein. To elucidate the function of YY1 pathogenesis in RA, we used a collagen-induced arthritis (CIA) mouse model with YY1 deficiency. Deficiency of YY1 reduced the severity of arthritis and joint destruction. Moreover, Th17 cells were dramatically reduced in YY1-deficient mice. The cytokine interleukin (IL)-17 was decreased in YY1-deficient CD4+ T cells ex vivo and in vivo. Interestingly, the level of signal transducer and activator of transcription 3 (STAT3), tumor necrosis factor-α, IL-17, IL-6, and IL-1ß were markedly decreased in YY1-deficient mice with CIA. The cytokine-inducing function of YY1 was more specific to IL-17 than to interferon-γ. YY1 plays a role in Th17 cell differentiation and RA pathogenesis. Our findings suggest that future RA therapies should target the regulatory mechanism involved in Th17 cell differentiation, in which YY1 may cooperate with the STAT3 signaling pathway.

Coenzyme Q10 Inhibits Th17 and STAT3 Signaling Pathways to Ameliorate Colitis in Mice.

Coenzyme Q10 (CoQ10) is a powerful antioxidant substance synthesized in the body. The current study aimed to determine whether CoQ10 suppresses inflammation and inhibits p-STAT3 expression in an experimental colitis mouse model. The mice were orally fed with CoQ10 once a day for 13 days. Histological analysis of the colons was performed by immunohistochemistry. Expression of IL-17, FOXP3, p53, AMPK, and mTOR and activation of p-STAT3 and p-STAT5 in lymph node and spleen tissues were detected by confocal microscopy of stained tissue sections. The relative mRNA expression was measured with real-time PCR, and protein levels were examined by western blot. CoQ10 reduced the disease activity index score and the colon histological score. It also reduced inflammatory mediators in the colon and increased the colon length. The expression of IL-17 and p-STAT3 was decreased with CoQ10 treatment. In contrast, CoQ10 treatment increased the expression of p-AMPK and FOXP3. Expression of anti-inflammatory cytokines was shown to increase in colitis mice treated with CoQ10. These results suggested that CoQ10 may reduce the severity of colitis and suppress inflammation through the inhibition of p-STAT3 and IL-17. These results support the use of CoQ10 as a potential targeted therapy for the treatment of colitis.

Epigallocatechin-3-gallate ameliorates autoimmune arthritis by reciprocal regulation of T helper-17 regulatory T cells and inhibition of osteoclastogenesis by inhibiting STAT3 signaling.

The green tea polyphenol epigallocatechin-3-gallate is a potent antioxidant. Here, we describe the effects of epigallocatechin-3-gallate on T cell differentiation and osteoclast differentiation in an animal model of arthritis. Mice with collagen-induced arthritis were injected intraperitoneally with epigallocatechin-3-gallate, 3 times/wk after the primary immunization. Surface markers of T helper 17 cells and regulatory T cells were analyzed by flow cytometry. Flow cytometry, Western blotting, and enzyme-linked immunosorbent assays were used to evaluate the effect of epigallocatechin-3-gallate on cell signaling in the collagen-induced arthritis model. Epigallocatechin-3-gallate decreased the arthritis index and showed protective effects against joint destruction in collagen-induced arthritis mice. The expression of cytokines, oxidative stress proteins, and phosphorylated-signal transducer and activator of transcription-3, 705 and 727, were significantly less in mice treated with epigallocatechin-3-gallate than it was in controls. Epigallocatechin-3-gallate reduced the expression of osteoclast markers in vitro and in vivo relative to the control, and the antiosteoclastic activity was observed in epigallocatechin-3-gallate-treated, interferon-γ knockout mice. The proportion of forkhead box protein 3-positive regulatory T cells was increased in the spleens of mice treated with epigallocatechin-3-gallate compared with control mice, whereas the proportion of T helper 17 cells was reduced. In vitro, the expression of nuclear respiratory factor 2, heme oxygenase-1, and extracellular signal-regulated kinase was increased significantly by epigallocatechin-3-gallate. We demonstrated that the administration of epigallocatechin-3-gallate attenuated the symptoms of arthritis, inhibited osteoclastogenesis and T helper 17 cell activation, and increased the number of regulatory T cells. At the molecular level, the antiarthritic effects of epigallocatechin-3-gallate may be due to induction of phosphorylated-extracellular signal-regulated kinase, nuclear respiratory factor 2, and heme oxygenase-1 and inhibition of signal transducer and activator of transcription-3 activation.

IL-12p40 Homodimer Ameliorates Experimental Autoimmune Arthritis.

IL-23 is the key cytokine that induces the expansion of Th17 cells. It is composed of p19 and p40 subunits of IL-12. The p40 subunit binds competitively to the receptor of IL-23 and blocks its activity. Our aim was to assess the preventive and therapeutic effect of the IL-12p40 homodimer (p40)2 subunit in autoimmune arthritis animal models. In the current study, using IL-1R antagonist-knockout mice and a collagen-induced arthritis model, we investigated the suppressive effect of (p40)2 on inflammatory arthritis. We demonstrated that the recombinant adenovirus-expressing mouse (p40)2 model prevented the development of arthritis when given before the onset of arthritis. It also decreased the arthritis index and joint erosions in the mouse model if transferred after arthritis was established. (p40)2 inhibited the production of inflammatory cytokines and Ag-specific T cell proliferation. It also induced CD4(+)CD25(+)Foxp3 regulatory T (Treg) cells in vitro and in vivo, whereas the generation of retinoic acid receptor-related organ receptor γt and Th17 cells was suppressed. The induction of Treg cells and the suppression of Th17 cells were mediated via activated STAT5 and suppressed STAT3. Our data suggest that (p40)2 suppressed inflammatory arthritis successfully. This could be a useful therapeutic approach in autoimmune arthritis to regulate the Th17/Treg balance and IL-23 signaling.

Rebamipide suppresses collagen-induced arthritis through reciprocal regulation of th17/treg cell differentiation and heme oxygenase 1 induction.

OBJECTIVE: Rebamipide, a gastroprotective agent, has the ability to scavenge reactive oxygen radicals. Increased oxidative stress is implicated in the pathogenesis of rheumatoid arthritis (RA). We undertook this study to investigate the impact of rebamipide on the development of arthritis and the pathophysiologic mechanisms by which rebamipide attenuates arthritis severity in a murine model of RA. METHODS: Collagen-induced arthritis (CIA) was induced in DBA/1J mice. Anti-type II collagen antibody titers and interleukin-17 (IL-17) levels were determined using enzyme-linked immunosorbent assay. The expression of transcription factors was analyzed by immunostaining and Western blotting. Frequencies of IL-17-producing CD4+ T cells (Th17 cells) and CD4+CD25+FoxP3+ Treg cells were analyzed by flow cytometry. RESULTS: Rebamipide reduced the clinical arthritis score and severity of histologic inflammation and cartilage destruction in a dose-dependent manner. The joints isolated from rebamipide-treated mice with CIA showed decreased expression of nitrotyrosine, an oxidative stress marker. Rebamipide-treated mice showed lower circulating levels of type II collagen-specific IgG, IgG1, and IgG2a. Whereas the number of Th17 cells in spleens was decreased in rebamipide-treated mice with CIA, a significant increase in the number of Treg cells in spleens was observed. In vitro, rebamipide inhibited Th17 cell differentiation through STAT-3/retinoic acid receptor-related orphan nuclear receptor γt and reciprocally induced Treg cell differentiation through FoxP3. Rebamipide increased Nrf2 nuclear activities in murine CD4+ T cells and LBRM-33 murine T lymphoma cells. Heme oxygenase 1 (HO-1) expression in the spleens was markedly increased in rebamipide-treated mice. CONCLUSION: The inhibitory effects of rebamipide on joint inflammation are associated with recovery from an imbalance between Th17 cells and Treg cells and with activation of an Nrf2/HO-1 antioxidant pathway.

Gene associated with retinoid-interferon-induced mortality 19 attenuates murine autoimmune arthritis by regulation of th17 and treg cells.

OBJECTIVE: STAT-3 is a key transcriptional factor in the interleukin-6 (IL-6)-mediated differentiation of Th17 cells. Because Th17 is believed to be a central player in rheumatoid arthritis (RA), we sought to evaluate whether an endogenous inhibitor of the STAT3 gene, GRIM-19 (gene associated with retinoid-interferon-induced mortality 19), could attenuate the progression and severity of murine collagen-induced arthritis (CIA) through suppression of Th17 cells and, reciprocally, could increase expression of Treg cells. METHODS: Overexpression of GRIM-19 was produced either by intravenous/intramuscular administration of a GRIM-19 overexpression vector in DBA1/J mice or by development of GRIM-19-transgenic (Tg) mice on a C57BL/6 background. Clinical signs were scored for arthritis severity, and mouse splenocytes, serum, and joint tissue were obtained for immunostaining and histologic analyses. RESULTS: The numbers of CD4+IL-17+ cells and CD4+pSTAT3+ cells were decreased, while the numbers of CD4+CD25+Foxp3+ cells and CD4+pSTAT5+ cells were increased, in both GRIM-19 vector-transfected and GRIM-19-Tg mice. Administration of the GRIM-19 overexpression vector into mice with CIA markedly suppressed the clinical and histologic signs of arthritis in the affected joints. Similarly, when CIA was induced in GRIM-19-Tg mice, the arthritis phenotype was markedly attenuated and the expression of inflammatory cytokines (IL-1ß, IL-6, tumor necrosis factor α, and IL-17) in the arthritic joints was also significantly reduced. Moreover, bone marrow-derived monocyte/macrophages obtained from GRIM-19-Tg mice showed attenuated RANKL-induced osteoclastogenesis in vitro. CONCLUSION: GRIM-19 improved the clinical and histologic features of CIA and also inhibited osteoclast formation. These findings suggest that GRIM-19 may be a novel treatment agent for RA.

Retinal attenuates inflammatory arthritis by reciprocal regulation of IL-17-producing T cells and Foxp3(+) regulatory T cells and the inhibition of osteoclastogenesis.

Retinoids (e.g., vitamin A and its derivatives) can regulate immune responses. The aim of this study was to determine whether all-trans retinaldehyde (retinal), a vitamin A derivative, can inhibit inflammatory responses and joint destruction in DBA/1J mice with collagen-induced arthritis (CIA). The arthritis score and incidence of arthritis were lower in mice treated with retinal compared to those treated with cottonseed oil. Histopathologic evidence of joint damage was lower in mice treated with retinal, corresponding with a reduction in the infiltration of immune cells in mice treated with retinal type II collagen (CII)-stimulated spleen cells. In addition, the expression of proinflammatory cytokines, oxidative stress proteins, and osteoclast markers were significantly reduced in mice treated with retinal. In vitro, retinal induced increased Foxp3 expression and inhibited Th17 development. The proportion of Foxp3(+) Treg cells was increased in the spleens of mice treated with retinal, whereas the proportion of Th17 cells was reduced. In both mice and a human culture system, tartrate-resistant acid phosphatase (TRAP) positive mononuclear cells and multinucleated cells were significantly reduced after treatment with retinal. The expression of osteoclast differentiation markers was dramatically decreased upon addition of retinal. This is the first study to demonstrate the therapeutic effect of retinal on an autoimmune arthritis model in mice through reciprocal regulation of Th17 and regulatory T cells and protection of differentiation and activation of osteoclasts. Taken together, our findings indicate that retinal has profound immunoregulatory functions and potential value for the treatment of autoimmune inflammatory disorders.