Recent Advances in Nonsteroidal Anti-Inflammatory Drugs

ABSTRACTRecent advances in basic and clinical researches of nonsteroidal anti-inflammatory drugs (NSAIDs) are reviewed. Concerning arachidonic acid cascade, recent studies revealed that not only cyclooxygenase (COX) but also terminal enzymes such as prostaglandin E synthase are very important in the understanding of the pathogenesis of inflammation and mechanisms of action of NSAIDs. We also found that some conventional NSAIDs and a selective COX-2 inhibitor exert pro-apoptotic effect on synovial fibroblasts and several cancer cells by COX-independent mechanisms. Clinical indications for use of NSAIDs are broad and include the following : rheumatic diseases ; painful and/or febrile conditions ; and prevention from thrombotic diseases such as myocardial infarction. In addition, recently developed selective COX-2 inhibitors have been found to be nearly as effective for the same conditions as conventional NSAIDs except with regard to the prevention of thrombosis. The incidence of severe gastrointestinal events in patients treated with selective COX-2 inhibitors has been proven to be lower than patients treated with conventional NSAIDs. However, there was no difference in renal complications between the two groups. Instead, an increased incidence of myocardial infarction after administration of selective COX-2 inhibitors may occur in patients with risk factors for atherosclerotic or thrombotic complications. Further basic and clinical studies remain to be investigated in the future

Selective cyclooxygenase-2 inhibitors show a differential ability to inhibit proliferation and induce apoptosis of colon adenocarcinoma cells

AbstractAlthough the influence of selective cyclooxygenase (COX)-2 inhibitors on the proliferation of colon adenocarcinoma cells have been the subject of much investigation, relatively little research has compared the effects of different COX-2 inhibitors. Celecoxib strongly suppressed the proliferation of COX-2 expressing HT-29 cells at 10–40 μM. NS-398 and nimesulide also inhibited cell proliferation, whereas rofecoxib, meloxicam, and etodolac did not. Only celecoxib induced apoptosis of HT-29 cells, as detected on the basis of DNA fragmentation, TUNEL positivity, and caspase-3/7 activation. DNA fragmentation was also increasd in COX-2 non-expressing cell lines (SW-480 and HCT-116) by exposure to celecoxib for 6–24 h. All six COX-2 inhibitors suppressed the production of prostaglandin E2 by HT-29 cells, suggesting that the pro-apoptotic effect of celecoxib was unrelated to inhibition of COX-2. Inactivation of Akt might explain the differential pro-apoptotic effect of these selective COX-2 inhibitors on colon adenocarcinoma cells

Triptolide, an active compound identified in a traditional Chinese herb, induces apoptosis of rheumatoid synovial fibroblasts

BACKGROUND: Extracts of Tripterygium wilfordii Hook F (TWHF), a traditional Chinese herb, have been reported to show efficacy in patients with rheumatoid arthritis (RA). Since RA is not only characterized by inflammation but also by synovial proliferation in the joints, we examined whether triptolide (a constituent of TWHF) could influence the proliferation of rheumatoid synovial fibroblasts (RSF) by induction of apoptosis. RESULTS: RSF were obtained from RA patients during surgery and were treated with triptolide under various conditions. The viability and proliferation of RSF were measured by the 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) assay and by 5-bromo-2'-deoxyuridine incorporation, respectively. Apoptosis was identified by detection of DNA fragmentation using an enzyme-linked immunosorbent assay and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL). The role of caspases in apoptosis of RSF was analyzed by measuring caspase-3 activity. Activation of the peroxisome proliferator-activated receptor (PPAR) γ was assessed by a luciferase reporter gene assay using RSF transfected with a plasmid containing the peroxisome proliferator response element. Triptolide decreased viability, inhibited proliferation, and induced apoptosis of RSF in a concentration-dependent manner at very low (nM) concentrations. Caspase-3 activity was increased by treatment with triptolide and was suppressed by caspase inhibitors. Although PPARγ activation was induced by 15-deoxy-Δ(12,14)-prostaglandin J(2), triptolide did not induce it under the same experimental conditions. An extract of TWHF also induced DNA fragmentation in RSF. CONCLUSION: The mechanism of action remains to be studied; however, triptolide may possibly have a disease-modifying effect in patients with RA

A Novel Mutation of Human Liver Alanine:Glyoxylate Aminotransferase Causes Primary Hyperoxaluria Type 1: Immunohistochemical Quantification and Subcellular Distribution

A novel alanine:glyoxylate aminotransferase (AGT) mutation involved in primary hyperoxaluria type 1 (PH1) was studied in Japanese patients. Two mutations in exon 7, c.751T>A and c.752G>A, lead to a W251K amino acid substitution. Proband 1 (patient 1) was homozygous for the W251K mutation allele (DDBJ Accession No. AB292648), and AGT-specific activity in the patient’s liver was very low. To reveal the cause of the low enzymatic activity, the intracellular localization of AGT (W251K) was studied using immunohistochemistry and immunoelectron microscopy. The latter analysis showed that patient 2 had only one-fifth of the normal AGT expression per catalase, suggesting impairment of AGT (W251K) dependent transport into peroxisomes. Peroxisomal transport of human AGT is believed to be dependent on the presence of the type 1 peroxisomal targeting sequence. The C-terminal tripeptide of AGT, KKL is necessary for peroxisomal targeting. In cultured cells, EGFP-AGT (W251K) localized both in the peroxisome and cytosol. These results were consistent with the data obtained from liver analysis of patient 2. The subcellular distribution of AGT (W251K) and the results from a random mutagenesis study suggest that KKL is necessary for peroxisomal targeting of human AGT, but additional signal other than KKL may be necessary

Membrane-associated prostaglandin E synthase-1 is upregulated by proinflammatory cytokines in chondrocytes from patients with osteoarthritis

Prostaglandin E synthase (PGES) including isoenzymes of membrane-associated PGES (mPGES)-1, mPGES-2, and cytosolic PGES (cPGES) is the recently identified terminal enzyme of the arachidonic acid cascade. PGES converts prostaglandin (PG)H(2 )to PGE(2 )downstream of cyclooxygenase (COX). We investigated the expression of PGES isoenzyme in articular chondrocytes from patients with osteoarthritis (OA). Chondrocytes were treated with various cytokines and the expression of PGES isoenzyme mRNA was analyzed by the reverse transcription–polymerase chain reaction and Northern blotting, whereas Western blotting was performed for protein expression. The subcellular localization of mPGES-1 was determined by immunofluorescent microscopy. Conversion of arachidonic acid or PGH(2 )to PGE(2 )was measured by enzyme-linked immunosorbent assay. Finally, the expression of mPGES-1 protein in OA articular cartilage was assessed by immunohistochemistry. Expression of mPGES-1 mRNA in chondrocytes was significantly induced by interleukin (IL)-1β or tumor necrosis factor (TNF)-α, whereas other cytokines, such as IL-4, IL-6, IL-8, IL-10, and interferon-γ, had no effect. COX-2 was also induced under the same conditions, although its pattern of expression was different. Expression of cPGES, mPGES-2, and COX-1 mRNA was not affected by IL-1β or TNF-α. The subcellular localization of mPGES-1 and COX-2 almost overlapped in the perinuclear region. In comparison with 6-keto-PGF(1α )and thromboxane B(2), the production of PGE(2 )was greater after chondrocytes were stimulated by IL-1β or TNF-α. Conversion of PGH(2 )to PGE(2 )(PGES activity) was significantly increased in the lysate from IL-1β-stimulated chondrocytes and it was inhibited by MK-886, which has an inhibitory effect on mPGES-1 activity. Chondrocytes in articular cartilage from patients with OA showed positive immunostaining for mPGES-1. These results suggest that mPGES-1 might be important in the pathogenesis of OA. It might also be a potential new target for therapeutic strategies that specifically modulate PGE(2 )synthesis in patients with OA

Study of active controlled tocilizumab monotherapy for rheumatoid arthritis patients with an inadequate response to methotrexate (SATORI): significant reduction in disease activity and serum vascular endothelial growth factor by IL-6 receptor inhibition therapy

We investigated the clinical efficacy and safety of tocilizumab (a humanized anti-IL-6 receptor antibody) monotherapy in active rheumatoid arthritis (RA) patients with an inadequate response to low dose methotrexate (MTX). In a multicenter, double-blind, randomized, controlled trial, 125 patients were allocated to receive either tocilizumab 8 mg/kg every 4 weeks plus MTX placebo (tocilizumab group) or tocilizumab placebo plus MTX 8 mg/week (control group) for 24 weeks. The clinical responses were measured using the American College of Rheumatology (ACR) criteria and the Disease Activity Score in 28 joints. Serum vascular endothelial growth factor (VEGF) levels were also monitored. At week 24, 25.0% in the control group and 80.3% in the tocilizumab group achieved ACR20 response. The tocilizumab group showed superior ACR response criteria over control at all time points. Additionally, serum VEGF levels were significantly decreased by tocilizumab treatment. The overall incidences of adverse events (AEs) were 72 and 92% (serious AEs: 4.7 and 6.6%; serious infections: 1.6 and 3.3%) in the control and the tocilizumab groups, respectively. All serious adverse events improved by adequate treatment. Tocilizumab monotherapy was well tolerated and provided an excellent clinical benefit in active RA patients with an inadequate response to low dose MTX

Identification of three Early Pleistocene tephras in and around the west part of the Musashino Upland, Tokyo, Northeast Japan

In and around the west part of the Musashino Upland, southwest of the Kanto Tectonic Basin, Ob4b-4 (1.62 Ma), Ob4b-1 (1.63 Ma), and Ob3 (1.71-1.78 Ma) tephras in the Kazusa Group, early Quaternary strata, were identified by using characteristic properties such as chemical composition of volcanic glass shards and titanomagnetite, and refractive indices of glass shards, hornblende, cummingtonite, and orthopyroxene. Changes in altitudes of Ob4b-1 identified in four cores and at three outcrops together with those by previous studies indicate geological structure of the Kazusa Group, revealing a gentle northeastward sloping with a gradient of 15/1000 and a prominent discontinuity of the strata along the Tachikawa Fault Zone

Humanized anti-interleukin-6-receptor antibody (tocilizumab) monotherapy is more effective in slowing radiographic progression in patients with rheumatoid arthritis at high baseline risk for structural damage evaluated with levels of biomarkers, radiography, and BMI: data from the SAMURAI study

Our aim was to assess the ability of tocilizumab monotherapy to reduce progressive structural joint damage in rheumatoid arthritis patients at high risk of progression. This study was a subanalysis from a prospective 1-year, multicenter, X-ray-reader-blinded, randomized controlled trial of tocilizumab [Study of Active Controlled Monotherapy Used for Rheumatoid Arthritis, an IL-6 Inhibitor (SAMURAI) trial]. All patients were categorized into two or three groups according to four independent predictive markers for progressive joint damage [urinary C-terminal crosslinking telopeptide (uCTX-II), urinary pyridinoline/deoxypyridinoline (uPYD/DPD) ratio, body mass index (BMI), and joint-space narrowing (JSN) score at baseline]. One-year progression of joint destruction was assessed in high-risk versus low-risk groups receiving tocilizumab monotherapy and compared with patients receiving conventional disease-modifying antirheumatic drugs (DMARDs) (n = 157 and 145, respectively). In patients at high risk of progression of erosion as estimated by high uCTX-II, uPYD/DPD, or low BMI, and at high risk of progression of JSN as estimated by low BMI or high JSN score, the 52-week changes in radiological erosion and JSN, respectively, were significantly less in patients treated with tocilizumab monotherapy compared with those receiving DMARDs for each type of risk factor. In patients at low risk, those receiving tocilizumab also progressed less than those on DMARDs, although the difference did not reach statistical significance. Tocilizumab monotherapy is more effective in reducing radiological progression in patients presenting with risk factors for rapid progression than in low-risk patients. Patients at high risk for progression may benefit more from tocilizumab treatment

Japan College of Rheumatology 2009 guidelines for the use of tocilizumab, a humanized anti-interleukin-6 receptor monoclonal antibody, in rheumatoid arthritis

The introduction of biological agents targeting tumor necrosis factor-alpha (TNF-α) has brought about a paradigm shift in the treatment of rheumatoid arthritis (RA). Although these anti-TNF agents have excellent efficacy against RA, a substantial number of patients still show inadequate responses. In Western countries, such patients are already being treated with new classes of antirheumatic drugs such as abatacept and rituximab. Tocilizumab (TCZ) is a humanized monoclonal antibody developed in Japan against the human interleukin-6 (IL-6) receptor. TCZ does not only alleviate the signs and symptoms of RA but also seems to prevent progressive bone and joint destruction. However, there is a concern that TCZ might increase the risk of adverse events such as infections since IL-6 plays a pivotal role in the immune system. Calculating the relative risks of specific adverse outcomes with TCZ use remains difficult, due to insufficient patient numbers enrolled in clinical trials to date. This review presents tentative guidelines for the use of TCZ for RA patients prepared by the Japan College of Rheumatology and based on results of clinical trials in Japan and Western countries. The guidelines are intended as a guide for postmarketing surveillance and clinical practice, and will be revised periodically based on the surveillance