Combined use of etanercept and MTX restores CD4⁺/CD8⁺ ratio and Tregs in spleen and thymus in collagen-induced arthritis

Suppression of Macrophage Activation by Sodium Danshensu via HIF-1α/STAT3/NLRP3 Pathway Ameliorated Collagen-Induced Arthritis in Mice

It is still a clinical challenge to sustain the remission of rheumatoid arthritis (RA); thus, identifying more effective and safer agents for RA treatment remains an urgent demand. We investigated the anti-arthritic activity and potential mechanism of action of sodium Danshensu (SDSS), a structurally representative water-soluble derivative of Danshen, on collagen-induced arthritis (CIA) mice. Our results showed that paw edema, synovium hyperplasia, bone destruction, and the serum levels of both IL-1β and IL-6 were ameliorated by SDSS (40 mg/kg·d) in CIA mice. In addition, there was no difference between SDSS and methotrexate (MTX, 2 mg/kg·3d) treatment in the above indicators. Further mechanism studies illustrated that SDSS inhibited IL-1β secretion by downregulating the HIF-1α/STAT3/NLRP3 pathway in macrophages. On the other hand, HIF-1α accumulation and HIF-1α/STAT3/NLRP3 pathway activation by IOX4 stimulation reduced the therapeutic effect of SDSS. These findings demonstrate that SDSS displays anti-arthritic activity in CIA mice and prevents proinflammatory cytokines secretion in macrophages by suppressing the HIF-1α/STAT3/NLRP3 pathway.

Regulating Th17/Treg Balance Contributes to the Therapeutic Effect of Ziyuglycoside I on Collagen-Induced Arthritis

To investigate the therapeutic effect and primary pharmacological mechanism of Ziyuglycoside I (Ziyu I) on collagen-induced arthritis (CIA) mice. CIA mice were treated with 5, 10, or 20 mg/kg of Ziyu I or 2 mg/kg of methotrexate (MTX), and clinical manifestations, as well as pathological changes, were observed. T cell viability and subset type were determined, and serum levels of transforming growth factor-beta (TGF-β) and interleukin-17 (IL-17) were detected. The mRNA expression of retinoid-related orphan receptor-γt (RORγt) and transcription factor forkhead box protein 3 (Foxp3) in mouse spleen lymphocytes was ascertained by the real-time reverse transcriptase-polymerase chain reaction (RT-qPCR). Molecular docking was used to detect whether there was a molecular interaction between Ziyu I and protein kinase B (Akt). The activation of mechanistic target of rapamycin (mTOR) in T cells was verified by Western blotting or immunofluorescence. Ziyu I treatment effectively alleviated arthritis symptoms of CIA mice, including body weight, global score, arthritis index, and a number of swollen joints. Similarly, pathological changes of joints and spleens in arthritic mice were improved. The thymic index, T cell activity, and RORγt production of Ziyu I-treated mice were significantly reduced. Notably, through molecular docking, western blotting, and immunofluorescence data analysis, it was found that Ziyu I could interact directly with Akt to reduce downstream mTOR activation and inhibit helper T cell 17 (Th17) differentiation, thereby regulating Th17/regulatory T cell (Treg) balance and improving arthritis symptoms. Ziyu I effectively improves arthritic symptoms in CIA mice by inhibiting mTOR activation, thereby affecting Th17 differentiation and regulating Th17/Treg balance.

Formulation of Glycyrrhizic Acid-based Nanocomplexes for Enhanced Anti-cancer and Anti-inflammatory Effects of Curcumin

In this study, nanocomplexes composed of glycyrrhizic acid (GA) derived from the root of the licorice plant (Glycyrrhiza glabra) were formulated for the delivery of curcumin (CUR). Sonication of amphiphilic GA solution with hydrophobic CUR resulted in the production of nanosized complexes with a size of 164.8 ± 51.7 nm, which greatly enhanced the solubility of CUR in aqueous solution. A majority of the CURs were released from these GA/ CUR nanocomplexes within 12 h. GA/CUR nanocomplexes exhibited excellent intracellular uptake in human breast cancer cells (Michigan cancer foundation-7/multi-drug resistant cells), indicating enhanced anti-cancer effects compared to that of free CUR. In addition, GA/CUR nanocomplexes demonstrated high intracellular uptake into macrophages (RAW264.7 cells), consequently reducing the release of the pro-inflammatory cytokine tumor necrosis factor-α. Furthermore, GA/CUR nanocomplexes successfully reduced the levels of serum pro-inflammatory cytokines and splenomegaly in a rheumatoid arthritis model.

TNF-α impairs EP4 signaling through the association of TRAF2-GRK2 in primary fibroblast-like synoviocytes

Our previous study showed that chronic treatment with tumor necrosis factor-α (TNF-α) decreased cAMP concentration in fibroblast-like synoviocytes (FLSs) of collagen-induced arthritis (CIA) rats. In this study we investigated how TNF-α impairs cAMP homeostasis, particularly clarifying the potential downstream molecules of TNF-α and prostaglandin receptor 4 (EP4) signaling that would interact with each other. Using a cAMP FRET biosensor PM-ICUE3, we demonstrated that TNF-α (20 ng/mL) blocked ONO-4819-triggered EP4 signaling, but not Butaprost-triggered EP2 signaling in normal rat FLSs. We showed that TNF-α (0.02-20 ng/mL) dose-dependently reduced EP4 membrane distribution in normal rat FLS. TNF-α significantly increased TNF receptor 2 (TNFR2) expression and stimulated proliferation in human FLS (hFLS) via ecruiting TNF receptor-associated factor 2 (TRAF2) to cell membrane. More interestingly, we revealed that TRAF2 interacted with G protein-coupled receptor kinase (GRK2) in the cytoplasm of primary hFLS and helped to bring GRK2 to cell membrane in response of TNF-α stimulation, the complex of TRAF2 and GRK2 then separated on the membrane, and translocated GRK2 induced the desensitization and internalization of EP4, leading to reduced production of intracellular cAMP. Silencing of TRAF2 by siRNA substantially diminished TRAF2-GRK2 interaction, blocked the translocation of GRK2, and resulted in upregulated expression of membrane EP4 and intracellular cAMP. In CIA rats, administration of paroxetine to inhibit GRK2 effectively improved the symptoms and clinic parameters with significantly reduced joint synovium inflammation and bone destruction. These results elucidate a novel form of cross-talk between TNFR (a cytokine receptor) and EP4 (a typical G protein-coupled receptor) signaling pathways. The interaction between TRAF2 and GRK2 may become a potential new drug target for the treatment of inflammatory diseases.

Comparison of CD4 Counts with Mycophenolate Mofetil versus Methotrexate from the First-line Antimetabolites as Steroid-sparing Treatment (FAST) Uveitis Trial

PURPOSE

Sub-analysis of the FAST Trial comparing change in CD4 (∆CD4) from baseline through 12 months in uveitis patients treated with mycophenolate mofetil (MMF) and methotrexate (MTX).

METHODS

Patients were randomly allocated to 1.5 g twice daily MMF or 25 mg weekly MTX. Individuals with CD4 counts at baseline, 6 months (or treatment failure prior), and 12 months (or treatment failure between 6 and 12 months) were included. The association between treatment and ∆CD4 (cells/μL) was analyzed using multivariable linear regression.

RESULTS

There was no significant difference in ∆CD4 between MMF and MTX at 6 months (-31.7 cells/μL for MMF compared to MTX; 95% CI: -358.2 to 294.8, P = .85) and 12 months (-78.3 cells/μL for MMF compared to MTX; 95% CI: -468.0 to 311.3; P = .69).

CONCLUSION

There was no significant difference in ∆CD4 between MMF and MTX from baseline to 12 months, suggesting that MMF does not confer additional risk of CD4 lymphopenia in uveitic patients.ClinicalTrials.gov Identifier: NCT01829295.

Treating Autoimmune Inflammatory Diseases with an siERN1-Nanoprodrug That Mediates Macrophage Polarization and Blocks Toll-like Receptor Signaling

The clinical application of small interfering RNA (siRNA) drugs provides promising opportunities to develop treatment strategies for autoimmune inflammatory diseases. In this study, siRNAs targeting the endoplasmic reticulum to nucleus signaling 1 (ERN1) gene (siERN1) were screened. Two cationic polymers, polyethylenimine (PEI) and poly(β-amino amine) (PBAA), which can improve the efficiency of the siRNA transfection, were used as siERN1 delivery carriers. They were implemented to construct a nanodrug delivery system with macrophage-targeting ability and dual responsiveness for the treatment of autoimmune inflammatory diseases. In terms of the mechanism, siERN1 can regulate the intracellular calcium ion concentration by interfering with the function of inositol 1,4,5-trisphosphate receptor 1/3 (IP3R1/3) and thus inducing M2 polarization of macrophages. Furthermore, siERN1-nanoprodrug [FA (folic acid)-PEG-R(RKKRRQRRR)-NPs(ss-PBAA-PEI)@siERN1] acts as a conductor of macrophage polarization by controlling the calcium ion concentration and is an inhibitor of MyD88-dependent Toll-like receptor signaling. The results revealed that the FA-PEG-R-NPs@siERN1 has universal biocompatibility, long-term drug release responsiveness, superior targeting properties, and therapeutic effects in mouse collagen-induced arthritis and inflammatory bowel disease models. In conclusion, this study reveals a potential strategy to treat autoimmune inflammatory disorders.

Targeted inhibition of GRK2 kinase domain by CP-25 to reverse fibroblast-like synoviocytes dysfunction and improve collagen-induced arthritis in rats

Rheumatoid arthritis (RA) is an autoimmune disease and is mainly characterized by abnormal proliferation of fibroblast-like synoviocytes (FLS). The up-regulated cellular membrane expression of G protein coupled receptor kinase 2 (GRK2) of FLS plays a critical role in RA progression, the increase of GRK2 translocation activity promotes dysfunctional prostaglandin E4 receptor (EP4) signaling and FLS abnormal proliferation. Recently, although our group found that paeoniflorin-6ʹ-O-benzene sulfonate (CP-25), a novel compound, could reverse FLS dysfunction via GRK2, little is known as to how GRK2 translocation activity is suppressed. Our findings revealed that GRK2 expression up-regulated and EP4 expression down-regulated in synovial tissues of RA patients and collagen-induced arthritis (CIA) rats, and prostaglandin E2 (PGE2) level increased in arthritis. CP-25 could down-regulate GRK2 expression, up-regulate EP4 expression, and improve synovitis of CIA rats. CP-25 and GRK2 inhibitors (paroxetine or GSK180736A) inhibited the abnormal proliferation of FLS in RA patients and CIA rats by down-regulating GRK2 translocation to EP4 receptor. The results of microscale thermophoresis (MST), cellular thermal shift assay, and inhibition of kinase activity assay indicated that CP-25 could directly target GRK2, increase the protein stability of GRK2 in cells, and inhibit GRK2 kinase activity. The docking of CP-25 and GRK2 suggested that the kinase domain of GRK2 might be an important active pocket for CP-25. G201, K220, K230, A321, and D335 in kinase domain of GRK2 might form hydrogen bonds with CP-25. Site-directed mutagenesis and co-immunoprecipitation assay further revealed that CP-25 down-regulated the interaction of GRK2 and EP4 via controlling the key amino acid residue of Ala321 of GRK2. Our data demonstrate that FLS proliferation is regulated by GRK2 translocation to EP4. Targeted inhibition of GRK2 kinase domain by CP-25 improves FLS function and represents an innovative drug for the treatment of RA by targeting GRK2.

Alterations in thymocyte populations under conditions of endotoxin tolerance

Background:

Endotoxin tolerance (ET) is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide (LPS) leads to dramatically elevated survival. Accumulating evidence has shown that peripheral T cells contribute to the induction of ET. However, what happens to T cell development in the thymus under ET conditions remains unclear. The purpose of this study was to analyze the alterations in thymocyte populations (double-positive [DP] and single-positive [SP] cells) under ET conditions.

Methods:

Mice were intraperitoneally injected with LPS at a concentration of 5 mg/kg to establish an LPS tolerance model and were divided into two groups: a group examined 72 h after LPS injection (72-h group) and a group examined 8 days after LPS injection (8-day group). Injection of phosphate-buffered saline was used as a control (control group). Changes in thymus weight, cell counts, and morphology were detected in the three groups. Moreover, surface molecules such as CD4, CD8, CD44, CD69, and CD62L were analyzed using flow cytometry. Furthermore, proliferation, apoptosis, cytokine production, and extracellular signal-regulated kinase (ERK) pathway signaling were analyzed in thymocyte populations. The polymorphism and length of the T-cell receptor (TCR) β chain complementarity-determining region 3 (CDR3) were analyzed using capillary electrophoresis DNA laser scanning analysis (ABI 3730).

Results:

Thymus weight and cell counts were decreased in the early stage but recovered by the late stage in a murine model of LPS-induced ET. Moreover, the proportions of DP cells (control: 72.130 ± 4.074, 72-h: 10.600 ± 3.517, 8-day: 84.770 ± 2.228), CD4⁺ SP cells (control: 15.770 ± 4.419, 72-h: 44.670 ± 3.089, 8-day: 6.367 ± 0.513), and CD8⁺ SP cells (control: 7.000 ± 1.916, 72-h: 34.030 ± 3.850, 8-day: 5.133 ± 0.647) were obviously different at different stages of ET. The polymorphism and length of TCR β chain CDR3 also changed obviously, indicating the occurrence of TCR rearrangement and thymocyte diversification. Further analysis showed that the expression of surface molecules, including CD44, CD69, and CD62L, on thymocyte populations (DP and SP cells) were changed to different degrees. Finally, the proliferation, apoptosis, cytokine production, and ERK pathway signaling of thymocyte populations were changed significantly.

Conclusion:

These data reveal that alterations in thymocyte populations might contribute to the establishment of ET.

Deficiency of β-arrestin2 exacerbates inflammatory arthritis by facilitating plasma cell formation

β-arrestin2 (β-arr2) is, a key protein that mediates desensitization and internalization of G protein-coupled receptors and participates in inflammatory and immune responses. Deficiency of β-arr2 has been found to exacerbate collagen antibody-induced arthritis (CAIA) through unclear mechanisms. In this study we tried to elucidate the molecular mechanisms underlying β-arr2 depletion-induced exacerbation of CAIA. CAIA was induced in β-arr2-/- and wild-type (WT) mice by injection of collagen antibodies and LPS. The mice were sacrificed on d 13 after the injection, spleen, thymus and left ankle joints were collected for analysis. Arthritis index (AI) was evaluated every day or every 2 days. We showed that β-arr2-/- mice with CAIA had a further increase in the percentage of plasma cells in spleen as compared with WT mice with CAIA, which was in accordance with elevated serum IgG1 and IgG2A expression and aggravating clinical performances, pathologic changes in joints and spleen, joint effusion, and joint blood flow. Both LPS stimulation of isolated B lymphocytes in vitro and TNP-LPS challenge in vivo led to significantly higher plasma cell formation and antibodies production in β-arr2-/- mice as compared with WT mice. LPS treatment induced membrane distribution of toll-like receptor 4 (TLR4) on B lymphocytes, accordingly promoted the nuclear translocation of NF-κB and the transcription of Blimp1. Immunofluorescence analysis confirmed that more TLR4 colocalized with β-arr2 in B lymphocytes in response to LPS stimulation. Depletion of β-arr2 restrained TLR4 on B lymphocyte membrane after LPS treatment and further enhanced downstream NF-κB signaling leading to additional increment in plasma cell formation. In summary, β-arr2 depletion exacerbates CAIA and further increases plasma cell differentiation and antibody production through inhibiting TLR4 endocytosis and aggravating NF-κB signaling.

Triterpene saponins from Guo-gang-long attenuate collagen-induced arthritis via regulating A20 and inhibiting MAPK pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The stems of Entada phaseoloides (L.) Merr commonly named "Guo-gang-long", is a traditional Chinese folk medicine that has been used clinically in China for the treatment of arthritis. Our previous study described that triterpene saponins isolated from "Guo-gang-long" could inhibit the inflammatory response. However, the potential mechanism of "Guo-gang-long" on treatment of arthritis, and whether the triterpene saponins responsible for its anti-arthritic effect are unclear.

AIM

To investigate the function and mechanisms of the triterpene saponins from E. phaseoloides (ES) in collagen-induced arthritis (CIA) rats.

MATERIALS AND METHODS

The chemical components of ES were analyzed by HPLC. Anti-arthritic activity of ES was investigated in CIA rats, which was established by immunization with bovine type II collagen. Three doses of ES (25, 50 and 100 mg/kg) were administrated using oral gavage to CIA rats daily for 3 weeks. The anti-arthritic activity of ES was evaluated by clinical arthritis scoring, paw swelling and mechanical sensitivity, as well as histological changes in CIA rats. The impacts of ES on the regulation of the ubiquintin-editing enzyme A20 and MAPK signaling pathway, and production of pro-inflammatory cytokines in CIA rats were examined by Western blot, quantitative real-time PCR, ELISA, and immunohistochemical staining, respectively.

RESULTS

ES treatment relieved the paw swelling, hyperalgesia and joint destruction, and prevented the progression of arthritis in CIA rats. Meanwhile, ES suppressed the excessive mRNA levels and protein expression of TNF-α and IL-17 in synovial tissues and hind paw joints, and reduced the production of IL-1β, TNF-α and IL-17 in serum. Furthermore, ES up-regulated A20 and suppressed the phosphorylation of p38 and ERK1/2 in hind paw joints, as well as inhibiting the activation of spinal p38 in CIA rats.

CONCLUSION

ES could relieve rheumatic symptoms and prevent the development of rheumatoid arthritis. The effects of ES may be mediated by reducing proinflammatory cytokine levels, up-regulating A20 expression, reducing p38 and ERK1/2 activation in periphery, and inhibiting of phospho-p38 in spinal cord.

Mesenchymal Stem Cells Enhance Therapeutic Effect and Prevent Adverse Gastrointestinal Reaction of Methotrexate Treatment in Collagen-Induced Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by articular destruction and functional loss. Methotrexate (MTX) is effective in RA treatment. However, MTX induces several adverse events and 20%-30% of patients do not respond to MTX. Thus, it is urgent to enhance the therapeutic effects and reduce the side effects of MTX. Recent studies showed that mesenchymal stem cells (MSCs) were participants in anti-inflammation, immunoregulation, and tissue regeneration. However, whether the combined application of MSCs and MTX promotes the therapeutic effects and reduces the side effects of MTX has not been studied. In this study, we used bovine type II collagen to induce rheumatoid arthritis in mice (collagen-induced arthritis, CIA). Then, CIA mice were subjected to MTX or MSC treatment, or both. The therapeutic effect and adverse events of different treatments on RA were evaluated with micro-CT, HE staining, and immunohistochemistry in vivo. Apoptosis and proliferation of MODE-K cells were measured after treated with MTX or/and cocultured with UCs. To test M2 polarization, Raw264.7 macrophages were stimulated by MTX with different concentrations or cocultured with UCs. We found that the combined application of MSCs and MTX increased the therapeutic effects on RA, as evidenced by decreased arthritis score, inflammatory responses, and mortality. Moreover, in this combination remedy, MTX prefers to suppress inflammation by facilitating macrophage polarization to M2 type while UCs prefer to eliminate gastrointestinal side effects of MTX via mitigating the apoptosis of intestinal epithelial cells. Thus, a combination of MTX and UCs is a promising strategy for RA treatment.

Cordycepin exhibits a suppressive effect on T cells through inhibiting TCR signaling cascade in CFA-induced inflammation mice model

Objective: Cordycepin has been shown to exhibit multiple pharmacological activities, such as antitumor, antifungi, antivirus, and immune-regulation activities, and is involved in the regulation of T cells. However, cordycepin that affects T cell activity is still not clear, and the molecular mechanism of cordycepin in regulation of TCR signaling has not yet been elucidated. In this study, the potential effect of cordycepin on T cells was observed in CFA-induced inflammation mice model, and the function of cordycepin in regulating TCR signaling cascade was investigated.Methods: A CFA-induced inflammation mice model was established for observing the effect of cordycepin on the thymus and spleen swellings, and T cell infiltration in paw tissue was detected by immunohistochemistry. The protein expression or phosphorilation was detected by western blotting, and the NFAT1 nuclear translocation was determined by fluorescence imaging. The cell proliferation, apoptosis, and IL-2 production were analyzed by CCK-8 method, flow cytometry, and ELISA.Results: In the mice model, the thymus and spleen swellings were suppressed and the T cell infiltration in paw tissue was inhibited by cordycepin at a concentration of 10 mg/kg. Although the expressions of ZAP70 and PLCγ1 were not significantly changed in the human T cell line Jurkat with cordycepin pretreatment, the CD3-antibody-induced phosphorylations of ZAP70 and PLCγ1 were markedly blocked. The protein level of p85 decreased when Jurkat cells were pretreated with cordycepin, and cordycepin blocked TCR downstream molecule Erk phosphorylation and NFAT1 nuclear translocation. Further investigation revealed that cordycepin inhibited T cell proliferation, reduced IL-2 production, and induced T cell apoptosis. Conclusions: These findings suggest that cordycepin regulates TCR signaling to inhibit excessive T cell activation in inflammation. Thus, cordycepin may be a potential therapeutic application in inflammation-associated diseases.

Evaluation of the antirheumatic effects of isoflavone-free soy protein isolate and etanercept in rats with adjuvant-induced arthritis

IMPACT STATEMENT

In view of the partial clinical benefit and significant toxicity of traditional rheumatoid arthritis (RA) treatments, there is a growing trend to use complementary therapy. The antiarthritic activity of soy is related to the effect of soy isoflavones. However, little is known about the antiarthritic activity of soy protein itself. This study demonstrates that soy protein isolate (SPI) and etanercept (ETN), a tumor necrosis factor-α (TNF-α) inhibitor, protect rats against the effects of adjuvant-induced arthritis (AIA) by reducing inflammation (TNF-α and matrix metalloproteinase-3), autoantibody production (anticyclic citrullinated peptide), and lipid peroxidation (malondialdehyde). Only SPI improved dyslipidemia accompanied by RA, giving it the advantage of reducing cardiovascular risk. Additionally, the severity of arthritis-induced pathology, including inflammatory infiltrates, synovial hyperplasia, pannus formation, synovial vascularity, and cartilage erosions, was reduced by both SPI and ETN. This research ascertains the possible antiarthritic effect of SPI, making it a recommended alternative therapy for RA.

Tibetan medicine Kuan-Jin-Teng exerts anti-arthritic effects on collagen-induced arthritis rats via inhibition the production of pro-inflammatory cytokines and down-regulation of MAPK signaling pathway

BACKGROUND

The stems of Tinospora sinensis (Lour.) Merr commonly named "Kuan-Jin-Teng" in Chinese, have been used to treat rheumatoid arthritis as a Tibetan medicine.

PURPOSE

The effects of the EtOAc fraction of ethanolic extract from the stems of T. sinensis (KJT) on the pro-inflammatory cytokines and MAPK pathway were studied in collagen-induced arthritis (CIA) model.

STUDY DESIGN

Anti-arthritic activity of KJT was investigated in CIA model.

METHODS

The chemical constituents of KJT were analyzed by LC-MS and HPLC. The CIA model was established with injecting the bovine CII emulsified in Freund's adjuvant in Wistar rats. Several doses of KJT (50.0, 100.0 and 200.0 mg/kg) were administrated via oral gavage to CIA rats daily for 4 weeks. The anti-arthritic activity of KJT was investigated by clinical arthritis scoring, paw swelling inspection and hyperalgesia measurement, as well as radiological and histological analysis in CIA rats. The impacts of KJT on the activation of MAPK pathway, production of pro-inflammatory cytokines (TNF-α, IL-1β and IL-17) in ankle joints, serum, and spleen in CIA rats were examined by western blot, immunohistochemical staining, ELISA, and quantitative real-time PCR respectively. Lastly, the effects of KJT on production of the nitric oxide (NO) and pro-inflammatory cytokines as well as the regulation of the phosphorylation of p38 and Erk were detected in lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophage cells.

RESULTS

KJT significantly alleviated the paw swelling, hyperalgesia and arthritic severity, and reduced the synovial tissue proliferation and inflammatory cell infiltration in the CIA rats. Moreover, KJT suppressed the production of TNF-α, IL-1β, and IL-17 in ankle joints, serum, and spleen and reversed the up-regulation of the phosphorylation of p38 and Erk in CIA rats. KJT was also demonstrated to inhibit the production of NO and pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), and phosphorylation of p38 and Erk in LPS-stimulated RAW264.7 cells.

CONCLUSION

These results suggest the mechanisms of KJT performing its anti-arthritis effect may be attributed to inhibiting the production of pro-inflammatory cytokines and down-regulating the MAPK signaling pathway.

Comparative Studies of Different Extracts from Eucommia ulmoides Oliv. against Rheumatoid Arthritis in CIA Rats

To compare efficacy of different extracts from Eucommia ulmoides Oliv. with both immune inflammation and joint destruction in collagen induced arthritis (CIA) rat model. Rats were divided into normal group (Nor), control group (CIA), TG group (treated with tripterygium glycoside), E70 group (treated with 70% ethanol extract from Eucommia ulmoides Oliv.), EA group (treated with ethyl acetate fraction from E70), and EN group (treated with n-butyl alcohol fraction from E70). All extracts from Eucommia ulmoides Oliv. could significantly inhibit ankle swelling, pathological manifestations, and cytokine levels in serum and spleen, by using foot volume measurement, H&E staining, ELISA, and RT-QPCR methods, respectively. All extracts could significantly inhibit rough joint surface and marginal osteophytes, improve RANKL/OPG ratio, and decrease MMP-9 expression, by using micro-CT and immunohistochemical staining. The activation of IKK/NF-κB signaling pathway was also inhibited by all extracts. In addition, ethyl acetate fraction from E70 presented better effect on RANKL/OPG system. This study identified effective extracts from Eucommia ulmoides Oliv. relieving immune inflammation and maintaining structural integrity of joints in CIA rats.

Antibody-based targeted delivery of interleukin-4 synergizes with dexamethasone for the reduction of inflammation in arthritis

Objectives

We have previously reported that F8-IL4, a fusion protein consisting of the F8 antibody specific to the alternatively-spliced extra domain A of fibronectin and of murine IL-4, cures mice with established arthritis, when used in combination with dexamethasone (DXM). The goal of this study was to assess whether other therapeutic agents, besides DXM, could induce cures in combination with F8-IL4 and to elucidate which leucocytes are most affected by the pharmacological treatment.

Methods

We performed therapy experiments in mice with CIA, using intravenous administrations of F8-IL4 in combination with DXM, MTX, murine cytotoxic T-lymphocyte-associated protein 4 fused to the fragment crystallizable portion of murine IgG2a, as well as mAbs to murine IL17A or the p40 subunit of murine IL12/IL23. Histology and immunohistochemistry for the identification of the various leucocytes were performed on the paws of mice euthanized at different therapy time points.

Results

Only the use of F8-IL4 in combination with DXM induced complete remissions, while all other combinations did not lead to cures. The light microscopical evaluation of paws with arthritis revealed a predominant infiltration of neutrophils, which substantially decreased 24 h after treatment with F8-IL4 and DXM.

Conclusion

The combination of F8-IL4 with DXM promotes a rapid anti-arthritic action by potently inhibiting neutrophil activity. A fully human analogue of F8-IL4 may find clinical utility for the treatment of neutrophil-driven chronic inflammatory conditions.

Inhibition of NF-κB pathway in fibroblast-like synoviocytes by α-mangostin implicated in protective effects on joints in rats suffering from adjuvant-induced arthritis

α-Mangostin (MG) is a bioactive compound isolated from mangosteen. This study was aimed to investigate effects of MG on adjuvant-induced arthritis (AA) in rats and decipher the underlying mechanisms. Clinical severity of AA was evaluated by paw oedema, arthritis score, and hematological parameters. Digital radiography (DR) and histological examinations were employed to assess joints destructions. Immune functions were evaluated by T cell subsets distribution. Effects on NF-κB pathway were investigated by immunohistochemical, western-blot and immunofluorescence methods both in vivo and vitro. It was found MG possessed superior anti-inflammatory effects in vivo, suggested by attenuated paw swelling, reduced inflammatory cells infiltration and decreased the secretion of TNF-α and IL-1β in serum. Meanwhile MG inhibited fibrous hyperplasia, synovial angiogenesis, cartilage and bone degradation in AA rats. Although MG exerted little effects on CD4⁺ population, it greatly decreased IFN-γ positive cells and promoted expression of FOXP3 in immune organs, indicating restoration of Th1/Treg cells ratio and recovery of immune homeostasis in vivo. Inhibition of NF-κB induced by MG was indicated by reduced the expression of p-p65 and VEGF in synovium. In vitro experiments found MG at 10 μg/ml significantly suppressed the expression and phosphorylation of key proteins implicated in NF-κB pathway and inhibited nucleus translocation of p65. These changes led to increased apoptosis and proliferation inhibition of HFLS-RA cells. The results demonstrated regulation of immune functions was deeply involved in the therapeutic actions of MG on AA, and it's inhibition on NF-κB in fibroblast-like synoviocytes was associated to the protective effects on joints.

Therapeutic effects of anti-CD154 antibody in cynomolgus monkeys with advanced rheumatoid arthritis

Rheumatoid arthritis is one major chronic inflammatory systemic autoimmune disease. The CD154-CD40 interactions play a critical role in the regulation of immune responses and the maintenance of autoimmunity. Therefore, we aimed to determine whether anti-CD154 antibody treatment show positive effects on immunomodulation and clinical improvement of sustained severe rheumatoid arthritis in cynomolgus monkeys. Arthritis was induced using chicken type II collagen (CII) and arthritic monkey were divided into control and anti-CD154 treatment groups based on their concentrations of anti-CII antibodies on week 7 post-immunization. Blood and tissue samples were collected on week 16 post-immunization. Anti-CD154 antibody treatment improved arthritis and movement, and significantly decreased the numbers of proliferating B cells and the serum levels of anti-type II collagen antibody and sCD154 compared with non-treatment group. Further anti-CD154 antibody treatment significantly decreased the percentage of CD4+ cells and the ratio of CD4+ to CD8+ T cells and significantly increased the percentage of CD8+ cells and effector memory CD8+ cells in peripheral blood. We have shown for the first time in a nonhuman primate model of RA that CD154 blockade has beneficial effects. This study might be valuable as preclinical data of CD154 blockade in nonhuman primate models of severe rheumatoid arthritis.

Combination Therapy of PEG-HM-3 and Methotrexate Retards Adjuvant-Induced Arthritis

At present, the early phenomenon of inflammatory angiogenesis is rarely studied in Rheumatoid arthritis (RA). Previous research found that PEG-HM-3, an integrin inhibitor, possessed anti-angiogenesis and anti-rheumatic activity. In this study, the advantages of inhibiting angiogenesis and immune cell adhesion and migration, as well as the benefits of anti-arthritis effects, were evaluated using a combination of PEG-HM-3 and methotrexate (MTX). In vitro, spleen cell proliferation and the levels of tumor necrosis factor α (TNF-α) in macrophage supernatant were assessed. Hind paw edema, arthritis index, clinical score, body weight and immunohistochemistry (IHC) of the spleen, thymus, and joint cavity were evaluated in vivo in adjuvant-induced arthritis rats. Joints of the left hind paws were imaged by X-ray. The expression of the toll-like receptor 4 (TLR-4) protein was assessed in lipopolysaccharide (LPS)-induced synoviocytes. PEG-HM-3 combined with MTX significantly reduced primary and secondary swelling of the hind paws, the arthritis index, the clinical score and bone erosion. The results of IHC showed that the levels of interleukin-6 (IL-6) in spleens and the levels of TNF-α, CD31 (cluster of differentiation 31), and CD105 in the joint cavity were decreased. The body weight of rats was maintained during combination therapy. Ankle cavity integrity, and bone erosion and deformity were improved in combination treatment. The expression of TLR-4 was significantly reduced with combination treatment in rat synoviocytes. Co-suppression of both inflammation and angiogenesis in arthritis was achieved in this design with combination therapy. The activity of nuclear transcription factor (NF-κB) and the expression of inflammatory factors were down regulated via integrin αvβ₃ and TLR-4 signaling pathways. In the future, the application of this combination can be a candidate in early and mid-term RA therapy.

Epigallocatechin gallate attenuates overload‑induced cardiac ECM remodeling via restoring T cell homeostasis

It has previously been demonstrated that Epigallocatechin gallate (EGCG) has regulatory effects on cellular immunity. The present study explored whether EGCG inhibits the overload‑induced cardiac extracellular matrix (ECM) remodeling through targeting the balance of T cell subpopulations. Sprague‑Dawley rats were subjected to either transverse aortic constriction (TAC) or sham operation. TAC rats were treated with EGCG or valsartan (Val) for 6 weeks. The administration of EGCG or Val ameliorated the overproduction of cardiac collagen, inhibited matrix metalloproteinase (MMP) activity, decreased the expression of tissue inhibitor of MMP‑2, atrial natriuretic peptide and brain natriuretic peptide. EGCG regulated the population of effector T cells and naïve T cells, restored the balance of T helper (Th) cell 17/regulatory T cells, via modulating the downstream regulator signal transducer and activator of transcription (STAT3) and STAT5. Furthermore, the ratio of interferon‑γ/interleukin (IL)‑10 which indicates the balance of Th1/Th2, was restored by the treatments at varying degrees. EGCG and Val administration rescued IL‑7 production, and decreased the level of IL‑15 in TAC rats. EGCG has positive therapeutic potential in inhibiting cardiac ECM remodeling. Regulation of the balance of T lymphocyte subsets may be one of the underlying mechanisms responsible for this effect.

Multiple Sclerosis: Immunopathology and Treatment Update

The treatment of multiple sclerosis (MS) has changed over the last 20 years. All immunotherapeutic drugs target relapsing remitting MS (RRMS) and it still remains a medical challenge in MS to develop a treatment for progressive forms. The most common injectable disease-modifying therapies in RRMS include β-interferons 1a or 1b and glatiramer acetate. However, one of the major challenges of injectable disease-modifying therapies has been poor treatment adherence with approximately 50% of patients discontinuing the therapy within the first year. Herein, we go back to the basics to understand the immunopathophysiology of MS to gain insights in the development of new improved drug treatments. We present current disease-modifying therapies (interferons, glatiramer acetate, dimethyl fumarate, teriflunomide, fingolimod, mitoxantrone), humanized monoclonal antibodies (natalizumab, ofatumumb, ocrelizumab, alentuzumab, daclizumab) and emerging immune modulating approaches (stem cells, DNA vaccines, nanoparticles, altered peptide ligands) for the treatment of MS.

Paroxetine alleviates T lymphocyte activation and infiltration to joints of collagen-induced arthritis

T cell infiltration to synovial tissue is an early pathogenic mechanism of rheumatoid arthritis (RA). In the present work, we reveal that G protein coupled receptor kinase 2 (GRK2) is abundantly expressed in T cells of collagen-induced arthritis (CIA). A GRK2 inhibitor, paroxetine protects the joints from inflammation and destruction, primarily through inhibition of both CD4+ helper T (Th) cell and CD8+ cytotoxic T (Tc) cell migration to synovial tissue. Meanwhile, paroxetine restores the balance of Th/Tc, effector Th (Theff)/ naïve Th (Thnaive) and effector Tc (Tceff)/ naïve Tc (Tcnaive) to equilibrium by elevating the frequency of Thnaive, Tcnaive and regulatory Th cells; reducing the increased Theff, activated Th and Tceff, having a similar effect as methotrexate (MTX). In addition, both serum and synovial IL-1β, TNF-α and CX3CL1 expression was effectively inhibited in treated rats. In vitro assay confirmed that paroxetine inhibits CX3CL1-induced T cell migration through blocking the activity of GRK2. Among three MAPK families, paroxetine was found to be able to decrease the phosphorylation of ERK. This study elucidates that paroxetine attenuates the symptoms of CIA rats due to its inhibitory effect on T cell activation and infiltration to synovial tissue via suppression of ERK pathway.

Contribution of CD8+ T cells to inflammatory cytokine production in systemic sclerosis (SSc)

Only limited attention has been paid to the role of CD8 + T cells in the etiopathogenesis and progression of systemic sclerosis (SSc). CD8 + T cells may have autoantigen-specific and pro-inflammatory but also immunomodulatory properties. To investigate the differentiation of CD8 + T cells, staining of cell surface factors and of chemokine receptors were performed. In addition, the cytokine-producing ability of circulating CD8 + T cells and their sensitivity to suppression by regulatory T cells (Tregs) were compared between patients with diffuse (dcSSc) or limited cutaneous SSc (lcSSc) and healthy individuals. We identified CD8 + T cells as producers of pro-inflammatory type-2 cytokines with a significant contribution of memory CD8 + T cells. Memory CD8 + T cells of SSc patients stayed unaltered after suppression with autologous Tregs. Expression of chemokine receptors was significantly correlated with intracellular cytokine production in CD8 + T cells with a clear dichotomy of type 1 and type 2 cytokines. High levels of intracellular cytokines, such as interleukin-(IL)-4, IL-13 and tumor-necrosis-factor-alpha (TNFalpha) were positively associated with the presence of Scl-70 or anti-centromere antibodies and negatively with the administration of glucocorticoids. Administration of glucocorticoids was positively associated with higher IFNgamma production. Lack of anti-centromere antibodies and therapy with methotrexate were positively associated with higher intracellular IL-10 production. CD8 + T cells may significantly contribute to inflammation in SSc. Our findings suggest to not only focus on T helper cells in the development of therapeutic strategies but also to consider the role of CD8 + T cells in the etiopathogenesis and perpetuation of SSc.

Role of the Gut Microbiome in Modulating Arthritis Progression in Mice

Genetics alone cannot explain most cases of rheumatoid arthritis (RA). Thus, investigating environmental factors such as the gut microbiota may provide new insights into the initiation and progression of RA. In this study, we performed 16S rRNA sequencing to characterise the gut microbiota of DBA1 mice that did or did not develop arthritis after induction with collagen. We found that divergence in the distribution of microbiota after induction was pronounced and significant. Mice susceptible to collagen-induced arthritis (CIA) showed enriched operational taxonomic units (OTUs) affiliated with the genus Lactobacillus as the dominant genus prior to arthritis onset. With disease development, the abundance of OTUs affiliated with the families Bacteroidaceae, Lachnospiraceae, and S24-7 increased significantly in CIA-susceptible mice. Notably, germ-free mice conventionalized with the microbiota from CIA-susceptible mice showed a higher frequency of arthritis induction than those conventionalized with the microbiota from CIA-resistant mice. Consistently, the concentration of the cytokine interleukin-17 in serum and the proportions of CD8+T cells and Th17 lymphocytes in the spleen were significantly higher in the former group, whereas the abundances of dendritic cells, B cells, and Treg cells in the spleen were significantly lower. Our results suggest that the gut microbiome influences arthritis susceptibility.

Ginsenoside compound K suppresses the abnormal activation of T lymphocytes in mice with collagen-induced arthritis

AIM

To investigate the anti-arthritis and immunomodulatory activities of ginsenoside compound K (C-K) in mice with collagen-induced arthritis (CIA).

METHODS

DBA/1 mice with CIA were treated with C-K (28, 56 or 112 mg·kg(-1)·d(-1), ig) or the positive control methotrexate (2 mg/kg, ig, every 3 d) for 34 d. Splenic T and B lymphocytes were positively isolated using anti-CD3-coated magnetic beads or a pan B cell isolation kit. T lymphocyte subsets, and CD28, T cell receptor (TCR), cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and programmed death-1 (PD-1) expression in purified splenic T lymphocytes were analyzed using flow cytometry, Western blotting and laser confocal microscopy.

RESULTS

C-K treatment significantly ameliorated the pathologic manifestations of CIA mice, remarkably inhibited T lymphocyte proliferation, and marginally inhibited the proliferation of B lymphocytes. C-K treatment significantly suppressed TNF-α and anti-CII antibody levels, and increased IFN-γ level in the joints of CIA mice, but did not alter IL-4 production. Treatment of CIA mice with C-K significantly decreased the percentages of activated T cells, co-stimulatory molecule-expressing T cells and effector memory T cells, and increased the frequencies of naive T cells and regulatory T cells. Furthermore, C-K treatment significantly decreased the expression of CD28 and TCR, whereas it increased the expression of CTLA-4 and PD-1 on T lymphocytes of CIA mice. Methotrexate treatment exerted comparable effects in all these experiments.

CONCLUSION

C-K suppresses the progression of CIA through regulating TCR, CD28, CTLA-4 and PD-1 expression, thus inhibiting the abnormal activation and differentiation of T lymphocytes.

Mycoplasma pneumoniae infection in children is a risk factor for developing allergic diseases

Mycoplasma pneumoniae (MP) infection is the dominant cause of pneumonia in children. We sought to determine the relationship between MP infection and secondary allergic disease and to clarify the associated mechanisms of inflammatory response. A prospective study was performed among 1330 patients diagnosed with pneumonia to investigate the patient immune status by determining the correlation between MP infection, immunoglobulin E (IgE) levels, and a spectrum of associated serum cytokines. Serum IgE, IL-4, IL-6, and IL-10 levels for MPP patients in the acute phase were obviously higher than those in the recovery phase (P < 0.01). MPP patients with allergic conditions had increased serum IgE levels and increased IL-4/INF-γ ratio, and IgE and Eosinophil Cationic Protein were further elevated in patients who eventually developed secondary asthma changes. Patients with severe pneumonia and high clinical pulmonary infection scores presented higher levels of IL-4 and IL-5 in serum than those with low scores (P < 0.01). The proportion of CD4+ and CD8+ T cells that secreted IL-4 was significantly increased in MPP patients with elevated IgE. Our data demonstrate a significant correlation between MP infection and IgE levels, which is associated with a Th1/Th2 cytokine imbalance.

Therapeutic potential of regulatory T cells in autoimmune disorders

Regulatory T cells (Tregs) play a dominant role in the regulation of immune responses. Quantitative and/or qualitative abnormalities of Tregs were observed in patients with autoimmune diseases and therapeutic interventions focusing Tregs are an attractive new target with the potential to cure these disorders. Biological agents approved for treatment of inflammatory rheumatic diseases transiently influence Treg prevalences and function and experimental therapies including novel biological agents, gene therapy, activation and ex vivo expansion of purified Tregs as well as substances influencing tolerogenic dendritic cells will be developed for selective Treg therapy. Although many of these interventions are effective in vitro, in animal models as well as in early clinical trials, significant concerns exist regarding the stability of Treg modifications as well as the long-term safety of Treg-based therapies.

T regulatory cells in childhood arthritis--novel insights

In recent years, there have been many new developments in the field of regulatory T cells (Treg), challenging the consensus on their behaviour, classification and role(s) in disease. The role Treg might play in autoimmune disease appears to be more complex than previously thought. Here, we discuss the current knowledge of regulatory T cells through animal and human research and illustrate the recent developments in childhood autoimmune arthritis (juvenile idiopathic arthritis (JIA)). Furthermore, this review summarises our understanding of the fields and assesses current and future implications for Treg in the treatment of JIA.

The effect of autoimmune arthritis treatment strategies on regulatory T-cell dynamics

PURPOSE OF REVIEW

Since their discovery over 15 years ago, intensive research has focused on the presence, phenotype and function of FOXP3(+) regulatory T cells (Treg) in autoimmune diseases such as rheumatoid arthritis (RA). The questions of whether Treg deficiencies underlie autoimmune pathology and whether or how Treg-related therapeutic approaches might be successful are still a subject of a vivid debate. In this review we give an overview of how current therapies influence Treg numbers and function in RA and juvenile idiopathic arthritis (JIA) and discuss these findings in the light of new Treg-based intervention strategies for autoimmune arthritis.

RECENT FINDINGS

The attempt to relate rheumatic diseases like rheumatoid arthritis and juvenile idiopathic arthritis to Treg has led to somewhat heterogeneous observations. So far, no clear defects in Treg numbers or function have been identified in autoimmune arthritis. The current standard therapies, that is methotrexate and biologicals, are generally effective, but the exact mechanism of action and their effect on Treg is not fully known. Nevertheless, the majority of in-vitro and ex-vivo data point towards a positive influence of these treatments on Treg number and function. These observations are not all consistent, however, and it is not known whether the observed effects on Treg are primary or secondary effects. To safely conduct targeted regulatory T-cell therapy in rheumatic diseases more knowledge about regulatory T-cell function in an inflammatory environment is needed that coincides with the initiative to elucidate the exact mechanism of current therapies.