The supplementary therapeutic DMARD role of low-dose glucocorticoids in rheumatoid arthritis

The management of rheumatoid arthritis (RA) is primarily based on the use of disease-modifying antirheumatic drugs (DMARDs), mainly comprising synthetic chemical compounds (that is, methotrexate or leflunomide) and biological agents (tumor necrosis factor inhibitors or abatacept). On the other hand, glucocorticoids (GCs), used for decades in the treatment of RA, are effective in relieving signs and symptoms of the disease, but also interfere with radiographic progression, either as monotherapy or in combination with conventional synthetic DMARDs. GCs exert most of their biological effects through a genomic action, using the cytosolic GC receptor and then interacting with the target genes within target cells that can result in increased expression of regulatory - including anti-inflammatory - proteins (transactivation) or decreased production of proinflammatory proteins (transrepression). An inadequate secretion of GCs from the adrenal gland, in relation to stress and inflammation, seems to play an important role in the pathogenesis and disease progression of RA. At present there is clear evidence that GC therapy, especially long-term low-dose treatment, slows radiographic progression by at least 50% when given to patients with early RA, hence satisfying the conventional definition of a DMARD. In addition, long-term follow-up studies suggest that RA treatment strategies which include GC therapy may favorably alter the disease course even after their discontinuation. Finally, a low-dose, modified night-release formulation of prednisone, although administered in the evening (replacement therapy), has been developed to counteract the circadian (night) rise in proinflammatory cytokine levels that contributes to disease activity, and might represent the way to further optimize the DMARD activity exerted by GCs in RA.     

Current perspective of TACE inhibitors: A review

Rheumatoid Arthritis (RA) is one of the most common autoimmune inflammatory conditions, affecting approximately 1% of the adult population worldwide. TNF-α is a pleitropic, pro-inflammatory cytokine which plays a pivotal role in the origin and progression of RA and other immune mediated disorders. The success of anti-TNF-α biological agents proved that inhibition of TNF-α could result in effective control of RA. Since the discovery of anti-TNF-α biologicals, much efforts have gone into developing an orally bioavailable small size TNF-α antagonist. One of the ways to block TNF-α in biological fluids is to inhibit TNF-α converting enzyme (TACE). This target has been validated in preclinical trials using TACE inhibitors. But, even after more than a decade no single TACE inhibitor has passed the Phase II clinical trials. Very recently, it has been shown that TACE inhibitors could also be used for inhibition of pathogenic EGFR signaling in cancer. Hence, TACE inhibitors could perform a dual role, in curing not only RA but also certain cancerous conditions. Developments in the field have prompted us to review the research work on TACE inhibitors, especially their structure activity relationships and molecular modeling studies.     

Dominance of the strongest: Inflammatory cytokines versus glucocorticoids

Pro-inflammatory cytokines are involved in the pathogenesis of many inflammatory diseases, and the excessive expression of many of them is normally counteracted by glucocorticoids (GCs), which are steroids that bind to the glucocorticoid receptor (GR). Hence, GCs are potent inhibitors of inflammation, and they are widely used to treat inflammatory diseases, such as asthma, rheumatoid arthritis and inflammatory bowel disease. However, despite the success of GC therapy, many patients show some degree of GC unresponsiveness, called GC resistance (GCR). This is a serious problem because it limits the full therapeutic exploitation of the anti-inflammatory power of GCs. Patients with reduced GC responses often have higher cytokine levels, and there is a complex interplay between GCs and cytokines: GCs downregulate pro-inflammatory cytokines while cytokines limit GC action. Treatment of inflammatory diseases with GCs is successful when GCs dominate. But when cytokines overrule the anti-inflammatory actions of GCs, patients become GC insensitive. New insights into the molecular mechanisms of GR-mediated actions and GCR are needed for the design of more effective GC-based therapies.     

Recognition of human tumor necrosis factor α (TNF-α) by therapeutic antibody fragment: energetics and structural features

Human tumor necrosis factor α (TNF-α) exists in its functional state as a homotrimeric protein and is involved in inflammation processes and immune response of a human organism. Overproduction of TNF-α results in the development of chronic autoimmune diseases that can be successfully treated by inhibitors such as monoclonal antibodies. However, the nature of antibody-TNF-α recognition remains elusive due to insufficient understanding of its molecular driving forces. Therefore, we studied the energetics of binding of a therapeutic antibody fragment (Fab) to the native and non-native forms of TNF-α by employing calorimetric and spectroscopic methods. Global thermodynamic analysis of data obtained from the corresponding binding and urea-induced denaturation experiments has been supported by structural modeling. We demonstrate that the observed high affinity binding of Fab to TNF-α is an enthalpy-driven process due mainly to specific noncovalent interactions taking place at the TNF-α-Fab binding interface. It is coupled to entropically unfavorable conformational changes and accompanied by entropically favorable solvation contributions. Moreover, the three-state model analysis of TNF-α unfolding shows that at physiological concentrations, TNF-α may exist not only as a biologically active trimer but also as an inactive monomer. It further suggests that even small changes of TNF-α concentration could have a considerable effect on the TNF-α activity. We believe that this study sets the energetic basis for understanding of TNF-α inhibition by antibodies and its unfolding linked with the concentration-dependent activity regulation.     

TNF—α和RANKL与类风湿关节炎的研究进展

类风湿关节炎（RA）是一种以慢性侵蚀性关节炎为特征的自身免疫性疾病,伴随有慢性滑膜炎症及继发的关节软骨和骨质的破坏。肿瘤坏死因子超家族（TNFSF）的成员,特别是肿瘤坏死因子-α／（TNF—α）和核因子-κB受体活化因子配体（RANKL）在疾病的炎症和骨破坏过程中发挥着至关重要的作用。一些靶向于TNFSF的生物制剂已被开发应用于RA的治疗。综述了TNF—α和RANKL在类风湿关节炎中的作用以及靶向药物的治疗效果。     

Myostatin induces tumor necrosis factor-α expression in rheumatoid arthritis synovial fibroblasts through the PI3K–Akt signaling pathway

In rheumatoid arthritis (RA), a chronic inflammatory disease, loss of muscle mass is an important contributor to the loss of muscle strength in RA patients. Myostatin, a myokine involved in the process of muscle hypertrophy and myogenesis, enhances osteoclast differentiation and inflammation. Here, we investigated the mechanisms of myostatin in RA synovial inflammation. We found a positive correlation between myostatin and tumor necrosis factor-α (TNF-α), a well-known proinflammatory cytokine, in RA synovial tissue. Our in vitro results also showed that myostatin dose-dependently induced TNF-α expression through the phosphatidylinositol 3-kinase (PI3K)–Akt–AP-1 signaling pathway. Myostatin treatment of human MH7A cells stimulated AP-1-induced luciferase activity and activation of the c-Jun binding site on the TNF-α promoter. Our results indicated that myostatin increases TNF-α expression via the PI3K–Akt–AP-1 signaling pathway in human RA synovial fibroblasts. Myostatin appears to be a promising target in RA therapy.     

Methotrexate chronotherapy is effective against rheumatoid arthritis

Methotrexate (MTX) is the most important drug for treating rheumatoid arthritis (RA). It has been stated that cytokines play an important role in the pathogenesis of RA, and that cytokine levels increase and show 24-h rhythms in RA patients. Previously, we found that arthritis was relieved after the administration of MTX at specific times in synchronization with the 24-h rhythm of tumor necrosis factor (TNF)-α in collagen-induced arthritis (CIA) animals. Based on our findings in an earlier study of the dosing time-dependent effects of MTX in MRL/lpr mice, which develop autoimmune disorders that share similarities with human RA, we examined here the utility of MTX chronotherapy in Japanese RA patients. In an initial animal modeling study, we collected blood from MRL/lpr mice at different times (2, 6, 10, 14, 18, or 22 hours after the light was turned on [HALO]), and we measured TNF-α mRNA expression in leukocytes. MTX was administered to the mice at two different dosing times (6 or 18 HALO), and various blood parameters were measured to estimate arthritis activity. TNF-α mRNA levels showed a clear 24-h rhythm with a peak at 22 HALO and a trough at 18 HALO after RA had developed. In these MRL/lpr mice, inflammation and TNF-α were markedly reduced when the MTX dosing time was matched to the time (18 HALO) when the TNF-α level began to increase. We then applied these findings to Japanese RA patients by switching them from the standard MTX three times/wk (day 1: after breakfast and supper; day 2: after breakfast schedule), to chronotherapy, in which the dose and number of doses/wk were not changed but MTX was administered once-a-day at bedtime. Disease Activity Score (DAS)28, modified health assessment questionnaire (MHAQ), and adverse effects were assessed. With MTX chronotherapy, DAS28, which is commonly used to quantitatively assess RA symptoms, was significantly improved at all follow-up clinical visit times compared with the baseline (vs. 1 mo: p?=?.0197, 2 mos: p?=?.0107, 3 mos: p?=?.0087). Significant symptom recovery was observed in 41.2% of patients, and 23.5% of patients achieved clinical remission during the 3 mos of follow-up. Functional capacity of RA patients, as indicated by the MHAQ, was markedly improved by chronotherapy. There were no severe adverse effects. Thus, we demonstrated (i) inflammation and plasma TNF-α concentrations were significantly reduced in MRL/lpr mice treated with MTX at 18 HALO, the time when TNF-α mRNA level began to increase; and (ii) MTX bedtime chronotherapy was safe, markedly reduced disease activity, and improved the functional capacity of RA patients. The findings on RA patients show that bedtime MTX chronotherapy can improve RA symptoms compared to the current standard dosing methods.     

Bioactive dietary peptides and amino acids in inflammatory bowel disease

Inflammatory bowel disease (IBD), most commonly ulcerative colitis (UC) and Crohn’s disease (CD), is a chronic inflammation of the gastrointestinal tract. Patients affected with IBD experience symptoms including abdominal pain, persistent diarrhea, rectal bleeding, and weight loss. There is no cure for IBD; thus treatments typically focus on preventing complications, inducing and maintaining remission, and improving quality of life. During IBD, dysregulation of the intestinal immune system leads to increased production of pro-inflammatory cytokines, such as TNF-α and IL-6, and recruitment of activated immune cells to the intestine, causing tissue damage and perpetuating the inflammatory response. Recent biological therapies targeting specific inflammatory cytokines or pathways, in particular TNF-α, have shown promise, but not all patients respond to treatment, and some individuals become intolerant to treatment over time. Dietary peptides and amino acids (AAs) have been shown to modulate intestinal immune functions and influence inflammatory responses, and may be useful as alternative or ancillary treatments in IBD. This review focuses on dietary interventions for IBD treatment, in particular the role of dietary peptides and AAs in reducing inflammation, oxidative stress, and apoptosis in the gut, as well as recent advances in the cellular mechanisms responsible for their anti-inflammatory activity.     

Perspectives for TNF-alpha-targeting therapies

Rheumatoid arthritis (RA) is the most common chronic autoimmunopathy, clinically leading to joint destruction as a consequence of the chronic inflammatory processes. The pathogenesis of this disabling disease is not well understood, but molecular events leading to tissue inflammation with cartilage and bone destruction are now better defined. Therapy with slow-acting, disease-modifying antirheumatic drugs (DMARDs), such as low-dose methotrexate, which is generally accepted as a standard, leads to a significant amelioration of symptoms but does not stop joint destruction. Due to these disappointing treatment options and the identification of certain inflammatory mediators as therapeutic targets, novel therapeutic agents such as monoclonal antibodies, cytokine-receptor/human-immunoglobulin constructs or recombinant human proteins have been tested in RA with some success. Clinical trials testing anti-TNF-alpha agents, alone or in combination with methotrexate, have convincingly shown the feasibility and efficacy of these novel approaches to the therapy of RA. A clinical trial testing combination therapy with chimeric (mouse/human) anti-TNF-alpha monoclonal antibody infliximab and methotrexate showed, for the first time in any RA trial, that there was no median radiological progression in the groups given infliximab plus methotrexate over a 12-month observation period. Similar encouraging results might arise from trials employing other TNF-alpha-directed agents, such as the fully human monoclonal antibody D2E7, the p75 TNF-alpha-receptor/Ig construct, etanercept, or others, as discussed in this review. Combination partners other than methotrexate will be established as suitable cotreatment along with anti-TNF-alpha biologicals. Forthcoming new indications for TNF-alpha-targeted therapies are discussed.     

Current state of therapy for pain and inflammation

Nonsteroidal anti-inflammatory drugs (NSAIDs), including both traditional nonselective NSAIDs and the selective cyclo-oxygenase (COX)-2 inhibitors, are among the most widely used medications in the USA. Traditional NSAIDs, although effective at relieving pain and inflammation, are associated with a significant increase in the risk for gastrointestinal adverse events. Throughout the 1990s these events were estimated to result in approximately 100,000 hospitalizations and 16,500 deaths each year nationally. Recent studies have indicated that the risk for serious NSAID gastropathy has declined substantially during the past decade as a result of a number of factors, including lower doses of NSAIDs, the use of gastroprotective agents such as proton pump inhibitors and misoprostol, and the introduction of the selective COX-2 inhibitors. One therapeutic approach that may reduce the risk for gastrointestinal side effects associated with traditional NSAIDs while retaining their efficacy is the inclusion of co-therapy with a proton pump inhibitor; these agents inhibit acid secretion and have been demonstrated to promote ulcer healing in patients with NSAID-related gastric ulcers. Alternatively, COX-2 selective agents have been used to treat patients at high risk for such events. Both nonselective and selective COX-2 inhibitors have now been shown to be associated with an increased risk for cardiovascular events. These studies, together with the outcomes of the recent US Food and Drug Administration decision to require 'black box' warnings regarding potential cardiovascular risks associated with NSAIDs, suggest that the use of COX-2 inhibitors as the sole strategy for gastroprotection in patients with arthritis and other pain syndromes must be reconsidered, particularly among those at risk for cardiovascular events.     

Substance P ameliorates collagen II-induced arthritis in mice via suppression of the inflammatory response

Current rheumatoid arthritis (RA) therapies such as biologics inhibiting pathogenic cytokines substantially delay RA progression. However, patient responses to these agents are not always complete and long lasting. This study explored whether substance P (SP), an 11 amino acids long endogenous neuropeptide with the novel ability to mobilize mesenchymal stem cells (MSC) and modulate injury-mediated inflammation, can inhibit RA progression. SP efficacy was evaluated by paw swelling, clinical arthritis scoring, radiological analysis, histological analysis of cartilage destruction, and blood levels of tumor necrosis factor-alpha (TNF-α) interleukin (IL)-10, and IL-17 in vivo. SP treatment significantly reduced local inflammatory signs, mean arthritis scores, degradation of joint cartilage, and invasion of inflammatory cells into the synovial tissues. Moreover, the SP treatment markedly reduced the size of spleens enlarged by excessive inflammation in CIA, increased IL-10 levels, and decreased TNF-α and IL-17 levels. Mobilization of stem cells and induction of T_reg and M2 type macrophages in the circulation were also increased by the SP treatment. These effect of SP might be associated with the suppression of inflammatory responses in RA and, furthermore, blockade of RA progression. Our results propose SP as a potential therapeutic for autoimmune-related inflammatory diseases.     

Approaches to the therapy of rheumatoid arthritis

The treatment of RA is generally empirical. While there are many effective agents available, there are no agents that are curative. Progressive disease is frequently seen even in patients who are responsive to current therapies. Newer, more effective therapies are needed. The most promising area for new treatments appears to be specific biologic approaches with monoclonal antibodies or stimulants or inhibitors of lymphocytokines.     

Methotrexate Chronotherapy is Effective Against Rheumatoid Arthritis

Methotrexate (MTX) is the most important drug for treating rheumatoid arthritis (RA). It has been stated that cytokines play an important role in the pathogenesis of RA, and that cytokine levels increase and show 24-h rhythms in RA patients. Previously, we found that arthritis was relieved after the administration of MTX at specific times in synchronization with the 24-h rhythm of tumor necrosis factor (TNF)-α in collagen-induced arthritis (CIA) animals. Based on our findings in an earlier study of the dosing time–dependent effects of MTX in MRL/lpr mice, which develop autoimmune disorders that share similarities with human RA, we examined here the utility of MTX chronotherapy in Japanese RA patients. In an initial animal modeling study, we collected blood from MRL/lpr mice at different times (2, 6, 10, 14, 18, or 22 hours after the light was turned on [HALO]), and we measured TNF-α mRNA expression in leukocytes. MTX was administered to the mice at two different dosing times (6 or 18 HALO), and various blood parameters were measured to estimate arthritis activity. TNF-α mRNA levels showed a clear 24-h rhythm with a peak at 22 HALO and a trough at 18 HALO after RA had developed. In these MRL/lpr mice, inflammation and TNF-α were markedly reduced when the MTX dosing time was matched to the time (18 HALO) when the TNF-α level began to increase. We then applied these findings to Japanese RA patients by switching them from the standard MTX three times/wk (day 1: after breakfast and supper; day 2: after breakfast schedule), to chronotherapy, in which the dose and number of doses/wk were not changed but MTX was administered once-a-day at bedtime. Disease Activity Score (DAS)28, modified health assessment questionnaire (MHAQ), and adverse effects were assessed. With MTX chronotherapy, DAS28, which is commonly used to quantitatively assess RA symptoms, was significantly improved at all follow-up clinical visit times compared with the baseline (vs. 1 mo: p?=?.0197, 2 mos: p?=?.0107, 3 mos: p?=?.0087). Significant symptom recovery was observed in 41.2% of patients, and 23.5% of patients achieved clinical remission during the 3 mos of follow-up. Functional capacity of RA patients, as indicated by the MHAQ, was markedly improved by chronotherapy. There were no severe adverse effects. Thus, we demonstrated (i) inflammation and plasma TNF-α concentrations were significantly reduced in MRL/lpr mice treated with MTX at 18 HALO, the time when TNF-α mRNA level began to increase; and (ii) MTX bedtime chronotherapy was safe, markedly reduced disease activity, and improved the functional capacity of RA patients. The findings on RA patients show that bedtime MTX chronotherapy can improve RA symptoms compared to the current standard dosing methods. (Author correspondence: hide-to@umin.net)     

Unmet needs in rheumatoid arthritis

Until the pathophysiology/etiology of rheumatoid arthritis (RA) is better understood, treatment strategies must focus on disease management. Early diagnosis and treatment with disease-modifying antirheumatic drugs (DMARDs) are necessary to reduce early joint damage, functional loss, and mortality. Several clinical trials have now clearly shown that administering appropriate DMARDs early yields better therapeutic outcomes. However, RA is a heterogeneous disease in which responses to treatment vary considerably for any given patient. Thus, choosing which patients receive combination DMARDs, and which combinations, remains one of our major challenges in treating RA patients. In many well controlled clinical trials methotrexate and other DMARDs, including the tumor necrosis factor-alpha inhibitors, have shown considerable efficacy in controlling the inflammatory process, but many patients continue to have active disease. Optimizing clinical response requires the use of a full spectrum of clinical agents with different therapeutic targets. Newer therapies, such as rituximab, that specifically target B cells have emerged as viable treatment options for patients with RA.     

不同运动方式对COPD 缓解期患者血清细胞因子的影响

目的:探讨IL-1、IL-6、TNF-α在COPD缓解期气道炎症中的作用及运动训练对COPD患者血清细胞因子的影响,为COPD患者制定最佳运动模式提供依据。方法:对55例临床缓解期的COPD患者进行为期12周运动训练,运动训练前后采用双抗体夹心ABC-ELISA法检测患者血清中细胞因子值,并与60名健康老年人比较。结果:COPD缓解期患者运动训练前,血清中IL-1、IL-6、TNF-α值均显著高于正常老年人组(P<0.01);经运动训练后,IL-1、TNF-α值显著下降(P<0.01),且不同运动训练方法,血清细胞因子变化幅度不同,以太极拳训练组IL-1、TNF-α下降的幅度最大(P<0.01)。结论:IL-1、IL-6、TNF-α参与了COPD缓解期气道慢性炎症反应,运动训练对致炎因子有下调作用,且太极拳运动训练下调效果较为明显。     

Cloning, expression, purification and characterization of a single chain variable fragment specific to tumor necrosis factor alpha in Escherichia coli

Anti TNF-α molecules have been used as therapeutic agents in a variety of human diseases such as Rheumatoid arthritis, Ankylosing spondylitis, Chron's diseases, Psoriasis, etc., where high levels of TNF-α plays a destructive role. The limitations of the present TNF-α inhibitors in terms of size, tissue penetration and immunogenicity, etc., provoked the search for small anti TNF-α molecules. In the present study, a single chain variable fragment (ScFv) construct was made from a monoclonal antibody of the class IgG raised against TNF-α was used. The anti TNF-α ScFv was well expressed as soluble form in Escherichia coli BL21 (DE3), which was purified to homogeneity by commercial methacrylate monolith-convective interaction media (CIM) supports using two different chemistries, immobilized metal affinity chromatography (IMAC) with copper ions followed by anion exchange chromatography. The anti TNF-α ScFv found to be inhibiting the TNF-α mediated cytotoxicity in MCF-7 cells with an IC₅₀ of 8 μg. Data presented here are promising and encouraging to further optimize anti TNF-α ScFv production in larger scale with higher recovery at a cheaper price for therapeutic purposes.     

Atherogenic effects of TNF-α and IL-6 via up-regulation of scavenger receptors

Patients with chronic inflammatory disorders such as rheumatoid arthritis (RA) have a high risk of developing cardiovascular disease. We evaluated the effects of TNF-α and IL-6 on foam cell formation, a pivotal process in atherogenesis. Accumulation of intracellular oxidized LDL (oxLDL) was induced when THP-1/macrophages were stimulated with TNF-α or IL-6. TNF-α induced the expressions of scavenger receptors SR-A and LOX-1, and IL-6 induced SR-A expression. Inhibition of the NF-κB signaling markedly decreased TNF-α-induced foam cell formation and SR-A expression. Serum from RA patients, but not healthy subjects, induced foam cell formation, which was partially reversed by either IL-6 or TNF-α blockade in conjunction with inhibiting the induction of scavenger receptors. The present study clearly showed that in patients with chronic inflammation mediated by TNF-α and IL-6, these cytokines are directly implicated in atherosclerotic plaque formation.