Anti-cytokine therapy for rheumatoid arthritis

Clinical biomarkers and pathogenic-related cytokines in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease with unknown etiology and pathogenesis. Although major therapeutic advances have been made in recent years, there is no cure for the disease. Current medications mainly reduce inflammation in order to relieve pain and slow joint damage, but many have potentially serious side effects. Therefore, to find specific biomarkers will benefit both RA patients to find relief from the disease and physicians to monitor the disease development. A number of biomarkers have been discovered and used clinically, and others are still under investigation. The autoantibodies, which are widely used in diagnosis and prognosis, novel biomarkers, which reflect clinical disease activity, and newly found biomarkers and pathogenic-related cytokines are discussed in this review.

Preparing the first responders: building the inflammatory transcriptome from the ground up

In cells of the immune system, inflammatory stimuli trigger highly coordinated cascades of gene activation that are precisely calibrated to the nature and strength of the stimulus. Herein, we describe the forces that control inflammatory gene transcription and highlight that many critical determinants of responsiveness are established prior to challenge. We discuss key steps in the transcription cycle that are regulated during gene activation and the importance of the underlying enhancer landscape. Further, we illustrate how the diversity in regulatory strategies employed at inflammatory genes provides novel opportunities for therapeutic intervention.

The future of osteoarthritis therapeutics: emerging biological therapy

Biological therapy is a thriving area of research and development, and is well established for chronic forms of rheumatoid arthritis (RA) and ankylosing spondylitis (AS). However, there is no clinically validated biological therapy for osteoarthritis (OA). Chronic forms of OA are increasingly viewed as an inflammatory disease. OA was largely regarded as a “wear and tear disease”. However, the disease is now believed to involve “low grade” inflammation and the growth of blood vessels and nerves from the subchondral bone into articular cartilage. This realization has focused research effort on the development and evaluation of biological therapy that targets proinflammatory mediators, angiogenic factors and cytokines in articular cartilage, subchondral bone and synovium in chronic forms of OA. This review article provides an overview of emerging biological therapy for OA, and discusses recent molecular targets implicated in angiogenesis and neurogenesis and progress with antibody-based therapy, calcitonin, and kartogenin, the small molecule stimulator of chondrogenesis.

The Therapeutic Potential of Anti-Interleukin-20 Monoclonal Antibody

Interleukin (IL)-20, a member of the IL-10 family of cytokines, was discovered in 2001. IL-20 acts on multiple cell types by activating on a heterodimer receptor complex of either IL-20R1–IL-20R2 or IL-22R1–IL-20R2. Recent evidence indicates that IL-20's interaction with its receptors might have proinflammatory effects on chronic inflammatory diseases, particularly rheumatoid arthritis (RA), osteoporosis, and breast cancer. Updated information about IL-20, such as its identification, expression, receptors, signaling, and biological activities, is illustrated in this review based on our research and the data available in the literature. IL-20 is a pleiotropic cytokine, which promotes inflammation, angiogenesis, and chemotaxis. IL-20 also regulates osteoclast differentiation by altering the receptor activator of NF-κB (RANK) and RANK ligand (RANKL) axis. Inflammation, angiogenesis, and osteoclastogenesis are critical for the pathogenesis of RA, osteoporosis, and breast cancer-induced osteolysis. Based on the in vitro and in vivo data and clinical samples, we demonstrated that IL-20 plays pivotal roles in these three diseases. In experimental models, anti-IL-20 monoclonal antibody ameliorates arthritis severity, protects against ovariectomized-induced bone loss, and inhibits breast tumor-induced osteolysis. This review presents the clinical implications of IL-20, which will lead to a better understanding of the biological functions of IL-20 in these diseases and provide new therapeutic options in the future.

Inhibitory effect of sodium houttuyfonate on synovial proliferation in vitro in cells from a patient with rheumatoid arthritis

The aim of the present study was to investigate the inhibitory effect of sodium houttuyfonate (SH) on synovial cell proliferation in vitro. Primary cells were obtained from the synovial tissue of a patient with rheumatoid arthritis (RA). The cells were divided into five treatment groups as follows: the control group (group 1), 25 μg/ml SH-treated group (group 2), 50 μg/ml SH-treated group (group 3), 100 μg/ml SH-treated group (group 4) and the 200 μg/ml SH-treated group (group 5). Following seven days of treatment, the proliferation rate of the synovial cells was then detected using an MTT assay. The expression level of proliferative synovial cells markedly decreased in the SH-treated groups in a dose-dependent manner compared with the control group. In conclusion, the present study demonstrated that SH was able to inhibit the proliferation of synovial cells obtained from a patient with RA. These results provide a potential theoretical basis for the development of a safe and effective treatment against RA in the future.

Synthesis and biological evaluation of new pyrazolone-pyridazine conjugates as anti-inflammatory and analgesic agents

A new series of pyrazolone-pyridazine conjugates 3 and 4a-l were synthesized and characterized by spectroscopic means and elemental analyses. All compounds were tested in vivo for their anti-inflammatory and analgesic properties against diclofenac, as reference compound. The synthesized compounds were also evaluated for their ability to inhibit the production of certain inflammatory cytokines such as TNF-α and IL-6 in serum samples. The ulcerogenic potential of the synthesized compounds was also determined. IC50 values for inhibition of COX-1 and COX-2 enzymes were investigated in vitro for the most active candidates. Molecular docking was performed on the active site of COX-2 to predict their mode of binding to the amino acids. Among the synthesized derivatives, compounds 4c and 4e showed good analgesic and anti-inflammatory activities with lower ulcer index than the reference drug.

The Preventive Effects of Nanopowdered Peanut Sprout-added Caciocavallo Cheese on Collagen-induced Arthritic Mice

The present study was carried out to investigate the effects of nanopowdered peanut sprout-added Caciocavallo cheese (NPCC) on the prevention and treatment of rheumatoid arthritis in DBA/IJ mice immunized with type II collagen. After the induction of arthritis, the mice were being divided into five groups: (1) normal, no immunization; (2) CIA, collagen-induced arthritis; (3) MTX, collagen-induced arthritis treated with methotrexate (0.3 mg/kg body weight); (4) CC, collagen-induced arthritis treated with Caciocavallo cheese (0.6 g/d); (5) NPCC, collagen-induced arthritis treated with nanopowdered peanut sprout-added Caciocavallo cheese (0.6 g/d). Nanopowdered peanut sprout was ranged from 300 to 350 nm, while regular powdered peanut sprouts were ranged from 50 to 150 μm. The NPCC group had considerable reductions of clinical scores and paw thicknesses at the end of experiment as compared to the CIA group. In the serum analysis, the TNF-α, IL-1β, IL- 6 and IgG1 levels in the NPCC group have decreased by 69.4, 75.9, 66.6, and 61.9%, respectively, when compared to the CIA group. The histological score and spleen index of the NPCC group were significantly lower than the CIA group. In conclusion, the feeding NPCC method could delay and/or prevent the rheumatoid arthritis in the collagen-induced arthritis mouse model. Based on this study, nanopowdered peanut sprouts could be applied to various functional cheeses.

Curcumin potentiates the anti-arthritic effect of prednisolone in Freund's complete adjuvant-induced arthritic rats

OBJECTIVES

The present study was aimed at investigating the effect of curcumin in combination with prednisolone for the effective treatment of arthritis with reduced side effects when glucocorticoids therapy is indicated.

METHODS

Arthritis was induced in wistar rats by subplantar injection of Freund's complete adjuvant, and animals were observed for the symptoms of arthritis during the period of 21 days. Combined treatment of curcumin with various doses of prednisolone (1.25, 2.5 and 5 mg/kg) was evaluated in order to ascertain the efficacy and toxicity induced by steroid.

KEY FINDINGS

Arthritic animals showed significant increase in tumour necrosis factor-α and IL-1β levels in paw tissue and IL-1β in serum. Combined therapy of curcumin with low doses of prednisolone showed pronounced beneficial effect on joint swelling, leucocyte count and biochemical parameters compared with prednisolone groups. Among the different doses used in the study, prednisolone at 1.25 mg/kg in combination with curcumin showed beneficial anti-arthritic activity and also reduced the steroid toxicity. This is evidenced by increase in body weight, low toxicity to immune organs, reduction in leucocyte count, increase in spleen anti-oxidant enzymes and potent inhibition of cytokines in combination group.

CONCLUSION

Therefore, combined treatment of curcumin with low doses of prednisolone may find therapeutic use in arthritis.

Metformin Down-regulates TNF-α Secretion via Suppression of Scavenger Receptors in Macrophages

Obesity is consistently increasing in prevalence and can trigger insulin resistance and type 2 diabetes. Many lines of evidence have shown that macrophages play a major role in inflammation associated with obesity. This study was conducted to determine metformin, a widely prescribed drug for type 2 diabetes, would regulate inflammation through down-regulation of scavenger receptors in macrophages from obesity-induced type 2 diabetes. RAW 264.7 cells and peritoneal macrophages were stimulated with LPS to induce inflammation, and C57BL/6N mice were fed a high-fat diet to generate obesity-induced type 2 diabetes mice. Metformin reduced the production of NO, PGE₂ and pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) through down-regulation of NF-κB translocation in macrophages in a dose-dependent manner. On the other hand, the protein expressions of anti-inflammatory cytokines, IL-4 and IL-10, were enhanced or maintained by metformin. Also, metformin suppressed secretion of TNF-α and reduced the protein and mRNA expression of TNF-α in obese mice as well as in macrophages. The expression of scavenger receptors, CD36 and SR-A, were attenuated by metformin in macrophages and obese mice. These results suggest that metformin may attenuate inflammatory responses by suppressing the production of TNF-α and the expressions of scavenger receptors.

Synthesis and biological evaluation of new heteroaryl carboxylic acid derivatives as anti-inflammatory-analgesic agents

A series of nicotinic acid derivatives structurally related to niflumic acid and certain pyridazine-containing compounds have been synthesized and characterized by analytical and spectral data. All compounds were screened for their potential analgesic and anti-inflammatory activities. The compounds which displayed analgesic and anti-inflammatory activities were tested for ulcerogenicity and screened for in vivo inhibition of certain inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2). Compounds 1c, 2a, 2b, and 5a have shown potent analgesic and anti-inflammatory activities.

Co-administration of water containing magnesium ion prevents loxoprofen-induced lesions in gastric mucosa of adjuvant-induced arthritis rat

Non-steroidal anti-inflammatory drugs (NSAIDs) comprise one of the most frequently used classes of medicines in the world; however, NSAIDs have significant side effects, such as gastroenteropathy, and rheumatoid arthritis patients taking NSAIDs are more susceptible to NSAID-induced gastric lesions as compared to patients with other diseases. In Asian countries, loxoprofen has been used clinically for many years as a standard NSAID. We demonstrate the preventive effect of the co-administration of water containing magnesium ion (magnesium water, 1-200 µg/kg) on the ulcerogenic response to loxoprofen in adjuvant-induced arthritis (AA) rats. Oral administration of loxoprofen (100 mg/kg) caused hemorrhagic lesions in the gastric mucosa of AA rats 14 d after adjuvant injection, and, following loxoprofen administration, the lesion score of AA rats was significantly higher than that of normal rats. The expression of inducible nitric oxide synthase (iNOS) mRNA and nitric oxide (NO) production in the gastric mucosa of AA rats were also increased by the administration of loxoprofen, and the increase in lesions and NO were prevented by the administration of aminoguanidine, an iNOS inhibitor. The co-administration of magnesium water decreased the ulcerogenic response to loxoprofen in AA rats. In addition, the co-administration of magnesium water attenuated the increase in iNOS mRNA expression and NO production in AA rats receiving loxoprofen. These results suggest that the oral co-administration of magnesium water to AA rats has a potent preventive effect on the ulcerogenic response to loxoprofen, probably by inhibiting the rise in iNOS and NO levels in the gastric mucosa.

Origins and actions of tumor necrosis factor α in postmenopausal breast cancer

Tumor necrosis factor α (TNFα) has many roles in both physiological and pathological states. Initially thought to cause necrosis of tumors, research has shown that in many tumor types, including breast cancer, TNFα contributes to growth and proliferation. The presence of TNFα-derived from the tumor and infiltrating immune cells-within a breast tumor microenvironment has been correlated with a more aggressive phenotype, and the postmenopausal ER+ subtype of breast cancers appears to strongly respond to its many pro-growth signaling functions. We discuss how TNFα regulates estrogen biosynthesis within the breast, affecting the activity of the key estrogen-synthesizing enzymes aromatase, estrone sulfatase, and 17β-HSD type 1. Additionally, we describe the anti-adipogenic actions of TNFα that are critical in preventing adjacent estrogen-producing adipose fibroblasts from differentiating, ensuring that the tumor maintains a constant source of estrogen-producing cells. We examine how the increased risk of developing breast cancer in older and obese individuals may be linked to the levels of TNFα in the body. Finally, we evaluate the feasibility of targeting TNFα and its associated pathways as a novel approach to breast cancer therapeutics.

Heat shock protein bystander antigens for peptide immunotherapy in autoimmune disease

Mucosal administration of an antigen eliciting bystander suppression at the site of inflammation results in effective antigen-specific immunotherapy for autoimmune diseases. Heat shock proteins are bystander antigens that are effective in peptide-specific immunotherapy in both experimental and human autoimmune disease. The efficacy of preventive peptide immunotherapy is increased by enhancing peptide-specific immune responses with proinflammatory agents. Combining peptide-specific immunotherapy with general suppression of inflammation may improve its therapeutic effect.

Thiazolidine-2,4-diones: progress towards multifarious applications

The promising activity shown by compounds containing thiazolidine-2,4-dione nucleus in numerous categories such as anti-hyperglycaemics, aldose reductase inhibitors, anti-cancer, anti-inflammatory, anti-arthritics, anti-microbials, etc. has made it an indispensable anchor for development of new therapeutic agents. Varied substituents on the thiazolidine-2,4-dione nucleus have provided a wide spectrum of biological activities. Importance of this nucleus in some activities like, peroxisome proliferator activated receptor γ (PPARγ) agonism and PPARγ-dependent and -independent anti-cancer activities are reviewed separately in literature. Short reviews on biological importance of this nucleus are also known in literature. However, owing to fast development of new drugs possessing thiazolidine-2,4-dione nucleus many research reports are generated in short span of time. So, there is a need to couple the latest information with the earlier information to understand the current status of thiazolidine-2,4-dione nucleus in medicinal chemistry research. In the present review, various derivatives of thiazolidine-2,4-diones with different pharmacological activities are described on the basis of substitution pattern around the nucleus combined with the docking studies performed in the active site of the corresponding receptors with an aim to help medicinal chemists for developing an SAR on thiazolidine-2,4-dione derived compounds for each activity. This discussion will further help in the development of novel thiazolidine-2,4-dione compounds.

Shuangtengbitong tincture treatment of collagen-induced arthritis via downregulation of the expression of IL-6, IL-8, TNF-α and NF-κB

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease and may lead to joint damage, synovial membrane destruction and cartilage and bone damage. RA is closely associated with increased expression of interleukin (IL)-6, IL-8, tumor necrosis factor-α (TNF-α) and nuclear transcription factor-κB (NF-κB). Therefore, inhibition of the expression of IL-6, IL-8, TNF-α and NF-κB is a promising strategy for the development of novel anti-RA therapies. The aim of this study was to investigate the effect of shuangtengbitong tincture (STBT) on the expression of IL-6, IL-8, TNF-α and NF-κB in synovial tissues of rats with collagen-induced arthritis (CIA). STBT as a clinical prescription created at Fujian University of Traditional Chinese Medicines (TCM) Affiliated People’s Hospital has been shown to be clinically effective in the treatment of RA. The model of Wistar rats with CIA was created using bovine type II collagen. The two treatment groups with CIA were administered STBT (1 ml per time) or Votalin (∼1 cm per time) for ∼1 month continuously. Following treatment, STBT suppressed paw swelling significantly (P<0.05) compared with the model group. STBT also improved pathological changes, STBT-treated rats showed a significant improvement in synovial hyperplasia, inflammatory infiltration, cartilage and bone destruction and other symptoms. The protein expression levels of IL-6, IL-8, TNF-α and NF-κB were markedly suppressed in synovial tissues of STBT-treated and Votalin-treated rats. Our findings demonstrate for the first time that STBT markedly reduces paw swelling, improves pathological changes and increases the expression of IL-6, IL-8, TNF-α and NF-κB in synovial tissues of CIA rats, which may partially explain the anti-RA activity of STBT.

Regulation of inflammatory responses in tumor necrosis factor-activated and rheumatoid arthritis synovial macrophages by JAK inhibitors

OBJECTIVE

JAK inhibitors have been developed as antiinflammatory and immunosuppressive agents and are currently undergoing testing in clinical trials. The JAK inhibitors CP-690,550 (tofacitinib) and INCB018424 (ruxolitinib) have demonstrated clinical efficacy in rheumatoid arthritis (RA). However, the mechanisms that mediate the beneficial actions of these compounds are not known. The purpose of this study was to examine the effects of both JAK inhibitors on inflammatory and tumor necrosis factor (TNF) responses in human macrophages.

METHODS

In vitro studies were performed using peripheral blood macrophages derived from healthy donors and treated with TNF and using synovial fluid macrophages derived from patients with RA. Levels of activated STAT proteins and other transcription factors were detected by Western blotting, and gene expression was measured by real-time polymerase chain reaction analysis. The in vivo effects of JAK inhibitors were evaluated in the K/BxN serum-transfer model of arthritis.

RESULTS

JAK inhibitors suppressed the activation and expression of STAT-1 and downstream inflammatory target genes in TNF-stimulated and RA synovial macrophages. In addition, JAK inhibitors decreased nuclear localization of NF-κB subunits in TNF-stimulated and RA synovial macrophages. CP-690,550 significantly decreased the expression of interleukin-6 in synovial macrophages. JAK inhibitors augmented nuclear levels of NF-ATc1 and cJun, followed by increased formation of osteoclast-like cells. CP-690,550 strongly suppressed K/BxN serum-transfer arthritis, which is dependent on macrophages, but not lymphocytes.

CONCLUSION

Our findings demonstrate that JAK inhibitors suppress macrophage activation and attenuate TNF responses and further suggest that suppression of cytokine/chemokine production and innate immunity contribute to the therapeutic efficacy of JAK inhibitors.

IL-1β enhances cell adhesion to degraded fibronectin

IL-1β is a prominent proinflammatory cytokine that mediates degradation of extracellular matrix proteins through increased expression of matrix metalloproteinases, which involves a signaling pathway in adherent cells that is restricted by focal adhesions. Currently, the mechanism by which IL-1β affects cell adhesion to matrix proteins is not defined, and it is not known whether degraded matrix proteins affect IL-1β signaling. We examined adhesion-related IL-1β signaling in fibroblasts attaching to native or MMP3-degraded fibronectin. IL-1β increased cell attachment, resistance to shear force and the numbers of focal adhesions containing activated β(1) integrins. IL-1β-enhanced attachment required FAK, kindlins 1/2, and talin. MMP3-degraded fibronectin-inhibited IL-1β-enhanced cell adhesion and promoted spontaneous ERK activation that was independent of IL-1β treatment. We conclude that IL-1β enhances the adhesion of anchorage-dependent cells to MMP3-degraded fibronectin, which, in turn, is associated with deregulated cellular responses to IL-1β. These data point to a novel role of IL-1β as a proadhesive signaling molecule in inflammation that employs kindlins and talin to regulate adhesion.

The anti-arthritic and anti-oxidative effect of NBD (6-nitro-1,3-benzodioxane) in adjuvant-induced arthritis (AIA) in rats

OBJECTIVES

The present study evaluated the anti-arthritic and anti-oxidative effects of 6-nitro-1,3-benzodioxane in the adjuvant-induced arthritis model in rats.

METHODS

Arthritis was induced in female rats by intradermal injection of MT37Ra. Arthritis was evaluated by arthritic score, body weight loss, paw volume measurement, and histological changes. The plantar test was used to evaluate the effect of NBD on hyperalgesia.

RESULTS

The hyperalgesia (p < 0.0001) and hind paw inflammation (p < 0.034) was significantly decreased with parallel increase in the body weight of the NBD-treated (25 mg/kg) group compared to arthritic control rats. The antioxidant activity analysis demonstrated that the treatment of NBD significantly suppressed the levels of nitric oxide (p < 0.001) and peroxide (p < 0.002) with a significant increase in the glutathione (p < 0.021) compared to the arthritic control group. Since the IL-1β and TNF-α are key pro-inflammatory cytokines in arthritis, we therefore measured their levels in the serum samples. In comparison to the arthritic control group, the NBD treatment significantly reduced the levels of IL-1β (p < 0.003) and TNF-α (p < 0.026).

CONCLUSION

Our results suggests that NBD is an anti-arthritic agent that not only reduces the severity of the disease process but also affects contributing factors of arthritic inflammation including free radicals and inflammatory cytokines production.

Scientific evidence and rationale for the development of curcumin and resveratrol as nutraceutricals for joint health

Interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) are key cytokines that drive the production of inflammatory mediators and matrix-degrading enzymes in osteoarthritis (OA). These proinflammatory cytokines bind to their respective cell surface receptors and activate inflammatory signaling pathways culminating with the activation of nuclear factor κB (NF-κB), a transcription factor that can be triggered by a host of stress-related stimuli including, excessive mechanical stress and ECM degradation products. Once activated, NF-κB regulates the expression of many cytokines, chemokines, adhesion molecules, inflammatory mediators, and several matrix-degrading enzymes. Therefore, proinflammatory cytokines, their cell surface receptors, NF-κB and downstream signaling pathways are therapeutic targets in OA. This paper critically reviews the recent literature and outlines the potential prophylactic properties of plant-derived phytochemicals such as curcumin and resveratrol for targeting NF-κB signaling and inflammation in OA to determine whether these phytochemicals can be used as functional foods.

Ocular Behçet disease: current therapeutic approaches

PURPOSE OF REVIEW

To alert physician to timely recognition and current treatment of recurrent hypopyon iridocyclitis or panuveitis in ocular Behçet disease (OBD).

RECENT FINDINGS

Interferon-α, rituximab, intravitreal triamcinolone, and biological response modifiers by tumor necrosis factor inhibitors such as infliximab and adalimumab are being used increasingly for the treatment of severe sight-threatening ocular inflammation including retinal vasculitis and cystoid macular edema (CME).

SUMMARY

Biological agents offer tremendous potential in the treatment of OBD. Given that OBD predominantly afflicts the younger adults in their most productive years, dermatologist, rheumatologist, internist, or general practitioners supervising patients with oculo-articulo-oromucocutaneous syndromes should be aware of systemic Behçet disease. Early recognition of ocular involvement is important and such patients should strongly be instructed to visit immediately an ophthalmologist, as uveitis management differs from extraocular involvements with high ocular morbidity from sight-threatening complications due to relapsing inflammatory attacks in the posterior segment of the eye. A single infliximab infusion should be considered for the control of acute panuveitis, whereas repeated long-term infliximab infusions were proved to be more effective in reducing the number of episodes in refractory uveoretinitis with faster regression and complete remission of CME.

Interleukin-19 blockade attenuates collagen-induced arthritis in rats

OBJECTIVES

RA is the most common form of inflammatory arthritis. IL-19 acts as a pro-inflammatory cytokine involved in the pathogenesis of RA. We investigated whether anti-IL-19 antibody treatment would modulate the severity of the disease in a CIA rat model.

METHODS

We generated a CIA model by immunizing rats with bovine type II collagen. CIA rats were s.c. treated with anti-IL-19 antibody 1BB1. The effects of 1BB1 on CIA rats were determined by hind-paw thickness, severity score, bone destruction, BMD and cytokine production, which were evaluated using radiological scans, micro-CT, real-time quantitative PCR and ELISA. To analyse gene regulation by IL-19, rat synovial fibroblasts (SFs) were isolated and analysed for the expression of TNF-α, IL-1β and RANK ligand (RANKL).

RESULTS

In vivo, IL-19 was highly expressed in the synovial tissue and SFs isolated from CIA rats. 1BB1 significantly ameliorated the severity of arthritis by decreasing hind-paw thickness and swelling; prevented bone destruction and bone loss; inhibited the expression of TNF-α, IL-1β, IL-6 and RANKL in synovial tissue; and decreased the production of IL-6 in serum. In vitro, IL-19-induced TNF-α, IL-1β, IL-6 and RANKL expression in CIA SFs.

CONCLUSIONS

Specifically blocking IL-19 inhibited pro-inflammatory cytokine production and prevented bone destruction in CIA rats. These findings provide evidence that IL-19 is a novel target, and that anti-IL-19 antibody may be a potential target to ameliorate the severity of RA.

Distinct effects of anti-tumor necrosis factor combined therapy on TH1/TH2 balance in rheumatoid arthritis patients

The immune balance in patients with rheumatoid arthritis (RA), a disease characterized by TH1 dominance, treated by the preferred combined anti-tumor necrosis factor (anti-TNF) and methotrexate (MTX) therapy was evaluated by assessing the chemokine and cytokine receptors as well as apoptosis induction. A meta-analysis of combined therapy by TNF blockers and MTX in 15 RA patients, MTX monotherapy in 20 RA patients, and 11 diagnosed but untreated RA patients was performed by assessing several immune markers in the whole lymphocyte population, as well as in specific CD4 cells, by both flow cytometry and image analysis. A significant downregulation of CXCR3 and IL-12 receptors (both TH1 markers) and a significant increase in the chemokine receptor CCR4 and, to a lesser extent, IL-4R (both TH2 markers) were found; a particularly marked increase was found in patients treated by combined therapy. This phenomenon was pronounced in CD4 cells and was accompanied by a high proportion of apoptotic cells. The therapeutic effect of MTX and TNF blockers may be due to apoptosis induction in lymphocytes infiltrating from the inflammation site and restoring the TH1/TH2 balance.

Cell-penetrating peptides can confer biological function: regulation of inflammatory cytokines in human monocytes by MK2 inhibitor peptides

Cell-penetrating peptides have been used as a method of delivering biologically active peptide for over two decades. In this paper, we covalently attached four different cell-penetrating peptides to a peptide that inhibits a kinase important in inflammation, mitogen-activated protein kinase activated protein kinase 2 (MAPKAP2 or MK2). We evaluated the specificity, toxicity, and functionality of these therapeutics in an in vitro model of inflammation using THP-1 monocytes. When treated with the MK2 peptide inhibitors, activated THP-1 human monocytes challenged with lipopolysaccharide (LPS) showed a decrease in TNF-α and IL-6 excretion without apparent toxicity. In addition, western blot analysis revealed decreases in the phosphorylation of heat shock protein 27 (HSP27), a downstream substrate of MK2. These results suggested that our peptides inhibited MK2 activity in vitro and should be investigated further as a potential therapeutic for applications involving inflammation. Furthermore, our results suggested that cell-penetrating peptides can be bioactive.

Inhibitory effects of a traditional Chinese herbal formula TBL-II on type II collagen-induced arthritis in mice

AIM OF THE STUDY

TBL-II is the water extract of an anti-arthritic Chinese herbal formula Tongbiling (TBL), which has been used to treat rheumatoid arthritis (RA) for many years. We herein aimed to confirm its anti-arthritic effect and explore the potential mechanism of action on collagen-induced arthritis (CIA) in mice.

MATERIALS AND METHODS

Four weeks after the first collagen immunization, mice were treated with TBL-II orally at a lower dose of 100mg/kg/d and higher dose of 300 mg/kg/d for 2 or 8 weeks. The severity of arthritis was evaluated by symptoms, radiological scores and histological assessment. Levels of IL-1β, IL-6, TNFα and IgG2a type anti-collagen II (CII) antibody in serum were measured by ELISA. Competitive RT-PCR and immunohistochemical analysis were used to investigate MMP-2, -3, -9 mRNA and protein expression.

RESULTS

Our results revealed treatment with higher dose of TBL-II for 2 weeks attenuated significantly acute inflammation, and decreased the amounts of IL-1β and TNFα in serum; treatment for 8 weeks could obviously suppress chronic inflammation, ameliorate cartilage and bone destruction, and reduce the levels of matrix metalloproteinase (MMP)-2, -3, -9 mRNA and protein expression in joints. The levels of IgG2a type anti-CII antibody in serum were significantly reduced by treatment with higher dose of TBL-II for either 2 or 8 weeks. In contrast, treatment with lower dose of TBL-II for 8 weeks had no effect on articular destruction.

CONCLUSIONS

Our results suggested that TBL-II at higher dose not only ameliorated symptoms but also modified disease of CIA. TBL-II would be a potent candidate as a novel botanical drug for further investigation.

Injectable hyaluronic acid-tyramine hydrogels for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease caused by inflammation of the synovial membrane, leading in turn to articular cartilage destruction. In this work, injectable tyramine modified hyaluronic acid (HA-Tyr) hydrogels were developed for the treatment of RA. HA-Tyr conjugate was synthesized by amide bond formation between carboxyl groups of HA and amine groups of tyramine. Then, HA-Tyr hydrogels were prepared by radical crosslinking reaction using H(2)O(2) and horse-radish peroxidase. Intra-articular injection of HA-Tyr hydrogels encapsulating dexamethasone (DMT) as a model drug resulted in successful treatment of RA with reduced interlukine-6, prostaglandin E2 and four types of cytokine levels in collagen-induced arthritis animal models. Histological analysis with hematoxylin and eosin (H&E) staining also confirmed the therapeutic effect of injectable HA-Tyr hydrogels with DMT. Taken together, the injectable HA-Tyr hydrogels were thought suitable to be developed as a therapeutically effective drug carrier for the treatment of RA.

The IL1alpha-S100A13 heterotetrameric complex structure: a component in the non-classical pathway for interleukin 1alpha secretion

Interleukin 1α (IL1α) plays an important role in several key biological functions, such as angiogenesis, cell proliferation, and tumor growth in several types of cancer. IL1α is a potent cytokine that induces a wide spectrum of immunological and inflammatory activities. The biological effects of IL1α are mediated through the activation of transmembrane receptors (IL1Rs) and therefore require the release of the protein into the extracellular space. IL1α is exported through a non-classical release pathway involving the formation of a specific multiprotein complex, which includes IL1α and S100A13. Because IL1α plays an important role in cell proliferation and angiogenesis, inhibiting the formation of the IL1α-S100A13 complex would be an effective strategy to inhibit a wide range of cancers. To understand the molecular events in the IL1α release pathway, we studied the structure of the IL1α-S100A13 tetrameric complex, which is the key complex formed during the non-classical pathway of IL1α release.

Ionic complex systems based on hyaluronic acid and PEGylated TNF-related apoptosis-inducing ligand for treatment of rheumatoid arthritis

The clinical applications of tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL), an emerging therapeutic protein for cancer and rheumatoid arthritis (RA), are limited by its instability and short biological half-life. In this study, efficient therapeutic modalities for RA treatment were developed in the form of nano-sized complexes (nanocomplexes) based on hyaluronic acid (HA) and polyethylene glycol (PEG)-derivatized TRAIL (PEG-TRAIL) formed by N-terminal specific PEGylation. The nanocomplexes were prepared by simply mixing the positively charged PEG-TRAIL and negatively charged HA, and showed negligible loss of bioactivity compared with the PEG-TRAIL. The in vivo biodistribution and diffusion kinetics of Cy5.5-labeled PEG-TRAIL in mice were observed using a near-infrared optical imaging system after subcutaneous injection of three different formulations: PEG-TRAIL in phosphate-buffered saline (PBS, pH 7.4), nanocomplex in PBS, or nanocomplex in 1% HA solution. The results suggested that PEG-TRAIL is released slowly in vivo from the nanocomplex in 1% HA. Experiments in a collagen-induced arthritis mouse model demonstrated that the magnitudes of therapeutic effects, as judged by clinical scores and histology, were significantly enhanced by the sustained delivery of PEG-TRAIL, with the order of nanocomplex in 1% HA>nanocomplex in PBS>PEG-TRAIL in PBS. In addition, sustained delivery of PEG-TRAIL from the nanocomplex in 1% HA resulted in significant reduction of serum inflammatory cytokines and collagen-specific antibodies that are responsible for the pathogenesis of RA. These results imply that HA/PEG-TRAIL nanocomplex formulations are promising therapeutic modalities for the treatment of RA.

Anti-inflammatory and Anti-arthritic Effects of a Novel Leflunomide Analogue, UTL-5b (GBL-5b)

Rheumatoid arthritis (RA) is a common disease characterized by chronic inflammation and irreversible destruction of articular cartilage and bone. In this report, we examined the anti-inflammatory and anti-arthritic effects of a novel leflunomide analogue, UTL-5b (also known as GBL-5b), for potential RA treatment. Using a carrageenan-induced edema study in rats, UTL-5b exhibited a better anti-inflammatory effect as compared with leflunomide and its metabolite. The chronic efficacy of UTL-5b was examined using type II collagen-induced arthritis (CIA) mouse model. UTL-5b exerted an anti-arthritic effect in a dose-dependant manner with mice given 30 mg/kg exhibiting amelioration of disease early in the trial, but losing statistical significance over time. In contrast, mice treated with 60 mg/kg showed reduced clinical disease parameters early in the trial and these effects were sustained over the ten week trial period. Mechanistic studies indicate that UTL-5b is an inhibitor of TNF-α production in vivo. Oral administration of UTL-5b prior to i.p. injection with lethal dose of lipopolysaccharide (LPS)/D-galactosamine markedly reduced the levels of serum TNF-α and increased survival rates of animals from septic shock-induced death. Acute toxicity study using mice receiving increasing doses of UTL-5b showed that no animals were killed by UTL-5b at 2,000 mg/kg (LD(50) >2,000 mg/kg). Our studies show that UTL-5b represents a novel anti-inflammatory and anti-arthritic agent with potential therapeutic application for RA treatment.

Interleukin-20 antibody is a potential therapeutic agent for experimental arthritis

OBJECTIVE

Interleukin-20 (IL-20) is a proinflammatory cytokine involved in the pathogenesis of rheumatoid arthritis (RA). We investigated whether anti-IL-20 antibody treatment would modulate the severity of the disease in a collagen-induced arthritis (CIA) rat model.

METHODS

We generated a CIA model by immunizing rats with bovine type II collagen. Rats with CIA were treated subcutaneously with anti-IL-20 antibody 7E, with the tumor necrosis factor (TNF) blocker etanercept, or with 7E in combination with etanercept. Arthritis severity was determined according to the hind paw thickness, arthritis severity score, degree of cartilage damage, bone mineral density, and cytokine production, which were evaluated using radiologic scans, microfocal computed tomography, and enzyme-linked immunosorbent assay. To analyze gene regulation by IL-20, rat synovial fibroblasts (SFs) were isolated and analyzed for the expression of RANKL, IL-17, and TNFα. We also used real-time quantitative polymerase chain reaction analysis and flow cytometry to determine IL-20-regulated RANKL in mouse osteoblastic MC3T3-E1 cells and Th17 cells.

RESULTS

In vivo, treatment with 7E alone or in combination with etanercept significantly reduced the severity of arthritis by decreasing the hind paw thickness and swelling, preventing cartilage damage and bone loss, and reducing the expression of IL-20, IL-1β, IL-6, RANKL, and matrix metalloproteinases (MMPs) in synovial tissue. In vitro, IL-20 induced TNFα expression in SFs from rats with CIA. IL-20 markedly induced RANKL production in SFs, osteoblasts, and Th17 cells.

CONCLUSION

Selectively blocking IL-20 inhibited inflammation and bone loss in rats with CIA. Treatment with 7E combined with etanercept protected rats from CIA better than treatment with etanercept alone. Our findings provide evidence that IL-20 is a novel target and that 7E may be a potential therapeutic agent for RA.

Anti-TNF-α agents in the treatment of immune-mediated inflammatory diseases: mechanisms of action and pitfalls

TNF-α is a potent inducer of the inflammatory response, a key regulator of innate immunity and plays an important role in the regulation of Th1 immune responses against intracellular bacteria and certain viral infections. However, dysregulated TNF can also contribute to numerous pathological situations. These include immune-mediated inflammatory diseases (IMIDs) including rheumatoid arthritis, Crohn’s disease, psoriatic arthritis, ankylosing spondylitis, ulcerative colitis and severe chronic plaque psoriasis. Animal and human studies concerning the role of TNF-α in IMIDs have led to the development of a therapy based on TNF blockage. This article focuses first on the potential mechanisms by which the three currently licensed agents, adalimumab, etarnecept and infliximab, decrease the inflammatory activity of patients with different IMIDs. Second, it focuses on the risks, precautions and complications of the use of TNF-α inhibitors in these patients.

Ameliorative effect of adalimumab on experimentally induced acute pancreatitis in rats

OBJECTIVES

In this study, the effects of adalimumab (ADA), a fully humanized IgG1 monoclonal antibody to tumor necrosis factor α, on experimentally acute pancreatitis (AP) were examined.

METHODS

Healthy Wistar rats (n = 32) were randomly divided into 4 groups: group 1, AP; group 2, AP + ADA; group 3, control (physiologic saline), and group 4, physiologic saline + ADA (n = 8/group). Acute pancreatitis was induced with a retrograde injection of 3% sodium (Na)-taurocholate into the common biliopancreatic duct. Adalimumab was simultaneously administered at 50 mg/kg intraperitoneally for groups 2 and 4. Physiologic saline was administered instead of Na-taurocholate for non-AP groups. After 24 hours, serum amylase, lactate dehydrogenase, pancreatic myeloperoxidase, and malondialdehyde activities, along with pancreatic histopathology, were examined.

RESULTS

Adalimumab treatment significantly decreased serum amylase activity (AP, 2778.25 ± 298.80; AP + ADA, 2143.13 ± 221.69; control, 1541.00 ± 148.39; ADA, 1143.00 ± 256.30 U/L; P < 0.001), lactate dehydrogenase activity (AP, 2978.37 ± 364.65; AP + ADA, 2582.75 ± 164.23; control 931.25 ± 135.93; ADA, 582.62 ± 99.37 U/L; P < 0.001), myeloperoxidase activity (AP, 1.44 ± 0.20; AP + ADA, 0.86 ± 0.01; control, 0.60 ± 0.17; ADA, 0.41 ± 0.00 U/g of wet tissue; P < 0.001), malondialdehyde activity (AP, 16.94 ± 3.98; AP + ADA, 7.66 ± 2.27; control, 9.07 ± 1.00; ADA, 3.58 ± 0.30 nmol/g; P < 0.01), and total histopathologic scores (AP, 2.75 ± 0.16; AP + ADA, 1.50 ± 0.19; control, 0.00 ± 0.00; ADA, 0.00 ± 0.00; P < 0.001).

CONCLUSIONS

These results support the idea that adalimumab might be beneficial for severity of AP.

Role of the cholinergic nervous system in rheumatoid arthritis: aggravation of arthritis in nicotinic acetylcholine receptor α7 subunit gene knockout mice

BACKGROUND

The alpha7 subunit of nicotinic acetylcholine receptors (alpha7nAChR) can negatively regulate the synthesis and release of proinflammatory cytokines by macrophages and fibroblast-like synoviocytes in vitro. In addition, stimulation of the alpha7nAChR can reduce the severity of arthritis in murine collagen-induced arthritis (CIA).

OBJECTIVE

To provide more insight into the role of the alpha7nAChR in the pathogenesis of arthritis by investigating the effect of the absence of alpha7nAChR in CIA in alpha7-deficient (alpha7nAChR(-/-)) compared with wild-type (WT) mice.

METHODS

CIA was induced in alpha7nAChR(-/-) and WT littermate mice at day 0 by immunisation with chicken collagen type II (cCII) followed by a booster injection with cCII on day 20. Mice were killed on day 44 or day 63 and arthritis activity as well as radiological and histological damage were scored. The effects on the immune response were evaluated by measurement of antigen-specific antibodies and cytokines, and evaluation of the effects on antigen-specific stimulated spleen cells.

RESULTS

In alpha7nAChR(-/-) mice a significant increase in the incidence and severity of arthritis as well as increased synovial inflammation and joint destruction were seen. Exacerbation of CIA was associated with elevated systemic proinflammatory cytokines and enhanced T-helper cell 1 (Th1)-cytokine and tumour necrosis factor alpha production by spleen cells. Moreover, a specific decrease in the collagen-specific 'Th1-associated' IgG2a response was seen, whereas IgG1 titres were unaffected.

CONCLUSIONS

The results presented here indicate that immune cell function in a model of rheumatoid arthritis is regulated by the cholinergic system and, at least in part, mediated by the alpha7nAChR.

Divergent effects of infliximab and anakinra therapies on macrophage phenotype from patients with refractory rheumatoid arthritis

Previously, we documented the co-expression of the inducible nitric oxide synthase (NOS2) and protein kinase C-eta (PKC-eta) in peripheral blood-derived macrophages (PBDM) from moderate to severe rheumatoid arthritis (RA) patients with elevated plasma nitric oxide levels but not from those with non-inflammatory osteoarthritis (OA) or normal plasma NO levels. The presence of PKC-eta was found to be required before macrophages could acquire the NOS2-positive phenotype and make copious levels of NO. In the current study, we report the divergent effects of two biological-based RA therapies which target TNFalpha function (infliximab) or IL1 response (anakinra) on the development of the NOS2-positive phenotype by PBDM in patients with refractory RA. Both infliximab and anakinra were effective in improving disease symptoms. However, treatment with anakinra, but not infliximab led to a complete suppression of NOS2 expression in PBDM and consequently, a more pronounced reduction in plasma NO levels. Data also revealed a requirement of both TNF-alpha and IL-1 in the development of the NOS2-positive macrophage phenotype. Finally, the data have shed light on the molecular mechanisms by which NO production may be regulated during disease progression to severe RA, and thus, offer a novel insight into the identification of future therapeutic targets for the treatment of inflammatory diseases.

Levels of transforming growth factor-beta are low in systemic lupus erythematosus patients with active disease

OBJECTIVE

Cytokines are central regulators of the immune response but the workings of this complex network in systemic lupus erythematosus (SLE) are not fully understood. We investigated a range of inflammatory and immune-modulating cytokines to determine their value as biomarkers for disease subsets in SLE.

METHODS

This was a cross-sectional study in 102 patients with SLE (87% women, disease duration 10.6 yrs). Circulating concentrations of interleukin 1β (IL-1β), IL-4, IL-6, IL-10, IL-12, IL-17, monocyte chemotactic protein 1 (MCP-1), macrophage inflammatory protein 1 (MIP-1α), MIP-1β, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and total transforming growth factor-β1 (TGF-β1) were related to disease activity (SLE Disease Activity Index; SLEDAI), lymphocyte subsets, autoantibody levels, accrued damage (Systemic Lupus International Collaborating Clinics/ACR Damage Index; SDI), and concomitant treatment.

RESULTS

Patients with SLE had lower levels of TGF-β1 (p = 0.01) and IL-1β (p = 0.0004) compared to controls. TGF-β1 levels were lower in patients with SLEDAI scores 1-10 and SDI > 3; and were correlated with CD4+, CD8+, and natural killer cell counts; and were independent of steroid or cytotoxic drug use. Treatment with cardiovascular drugs was associated with lower IL-12 levels. No consistent disease associations existed for the other cytokines investigated.

CONCLUSION

Lower TGF-β1 was the most consistent cytokine abnormality in patients with SLE. The associations with disease activity, lymphocyte subsets, and damage suggest that TGF-β1 may be a therapeutic target of interest in SLE.

Antibodies against cyclic citrullinated peptide don't decrease after 6 months of infliximab treatment in refractory rheumatoid arthritis

Anti-citrullinated peptide antibodies (ACPA) and the rheumatoid factor (RF) are well-established serological markers for rheumatoid arthritis (RA). ACPA are very useful in the diagnosis of RA, especially at the early stages of the disease when ACPA have a greater diagnostic value than RF. The aim of the study was to assess the influence of infliximab treatment on RF IgM and ACPA serum levels and RA activity during 6 months of treatment. Thirty-two patients with refractory RA were treated with infliximab during a 6-month period. At baseline, 3 and 6 months of treatment the patients were examined for the number swollen and tender joints out of 28 (SJC, TJC) and the visual analogue scale of arthritis activity according to the patient (VAS). Serum samples were tested for erythrocyte sedimentation rate (ESR), C-reactive protein level (CRP), ACPA and RF IgM. The disease activity score (DAS-28) parameter was also calculated at the same time. During the course of our study, we observed statistically significant improvement in ESR, CRP, TJC, SJC, VAS DAS-28, and RF IgM after 3 and 6 months of infliximab treatment when compared to the baseline, whereas the ACPA level remained unchanged after 3 and 6 months of treatment (P = 0.96 and P = 0.85). The changes in the ACPA level are not a factor for evaluation of successful infliximab treatment but the changes in RF IgM are. According to different behavior of these antibodies during infliximab treatment, we suggest that the roles of ACPA and RF in the pathogenesis of RA are different.

N-(2-hydroxy phenyl) acetamide inhibits inflammation-related cytokines and ROS in adjuvant-induced arthritic (AIA) rats

The present study was carried out to study the anti-arthritic and anti-inflammatory activity of N-(2-hydroxy phenyl) acetamide in adjuvant-induced arthritis in adult female Sprague Dawley rats. During experimental period, body weight and paw oedema volume were observed. At the end of each experiment, plasma and serum samples were collected and used for estimation of pro-inflammatory cytokines IL-1 beta and TNF-alpha and oxidative stress markers i.e., nitric oxide, peroxide and GSH. Our results suggested that, the reduction in body weight and increase in paw oedema volume were significantly retarded in the AIA rats receiving 5mg/kg and 10mg/kg doses of N-(2-hydroxy phenyl) acetamide as compared to diseased control animals. The serum levels of IL-1 beta and TNF-alpha were reduced as compared to those in the diseased control group. Treatment with N-(2-hydroxy phenyl) acetamide also altered oxidative stress markers in relation to its anti-inflammatory activity. Based on our results, it can be concluded that N-(2-hydroxy phenyl) acetamide possesses promising anti-arthritic property.