Publications

Background Nuclear factor of activate T cells (NFAT), consists of five members and plays a pivotal role in regulating T lymphocyte activation. Among the five subtypes of NFAT, NFAT1, NFAT2 and NFAT4 were recognized as the key family members associated with allergic diseases. However, evidence regarding the functions of NFAT1 and NFAT2 in Th2 cells are still conflicting. Aims and objectives Therefore, we explored the functions of NFAT1 and NFAT2 on Th2 lymphocytes. Methods Knockdown of NFAT1 and NFAT2 using small interfering RNA (siRNA) was performed in the murine Th2 lymphocyte cell line (D10.G4.1). Real-time qPCR, Western Blotting and ELISA were performed to test the relatively expression ofTh2 cytokine mRNA and protein in cells and culture supernatant. Results D10 cells express IL-4, IL-5, IL13 and GATA3mRNA level. NFAT1 siRNA and NFAT2 siRNA selectively suppressed the expression of NFAT1 and NFAT2 respectively at both the mRNA and protein level. Higher levels of IL-4, IL-5 and IL-13 were seen in NFAT1 siRNA treated Th2 cells. This suggests that NFAT1 may play a negative role in Th2 cytokine expression. Interestingly, the opposite effect was seen with NFAT2 siRNA. NFAT2 siRNA down-regulated the expression of IL-4, IL-5 and IL13 mRNA levels. This was associated with a reduction in the expression of GATA3 mRNA and protein. Conclusions NFAT1 may play a negative role in regulating Th2 cytokines whilst NFAT2 may have the opposite effect.

No abstract is provided for this article.

How Can We Predict Reversibility of Organ Dysfunction After Implantation of Left Ventricular Assist Device?Norihide Fukushima •••

Theophylline is the most widely used anti-asthma drug worldwide and is classified as a bronchodilator, although there is increasing evidence that it may have immunomodulatory effects. We have investigated the effects of theophylline withdrawal under placebo control in 27 asthmatic patients (25 to 70 yr) treated with long-term theophylline who were also treated with high dose inhaled corticosteroids. We measured asthma symptoms (diary card), lung function (spirometry and home records of peak expiratory flow), and peripheral leukocyte populations using dual color flow cytometry. In eight of these patients, we examined fiberoptic bronchial biopsies by immunocytochemistry. We also studied peripheral blood lymphocytes in eight asthmatic patients who have never received theophylline. Mean steady state plasma theophylline concentrations during theophylline therapy were 8.6 +/- 0.9 mg/L. Theophylline withdrawal was associated with a significant increase in asthma symptoms, particularly at night, and a fall in spirometry and morning peak flow. This was accompanied by a significant fall in peripheral blood monocytes (CD14+, activated CD4+ T-lymphocytes (CD4+/CD25+) and activated CD8+ T-cells (CD8+/HLA-DR+) in patients with a plasma theophylline > 5 mg/L. The lymphocyte populations in theophylline-naive patients were similar to those found after theophylline withdrawal. Bronchial biopsies showed a mirror image of the peripheral blood with an increase in CD4+ and CD8+ lymphocytes in the airway. Chronic treatment with theophylline, even at low plasma concentrations, controls asthma symptoms and has effects on T-lymphocyte populations in the peripheral blood which are the inverse of those observed in the airways.(ABSTRACT TRUNCATED AT 250 WORDS)

Background— Whether premature dual antiplatelet therapy (DAPT) interruption is safe in patients receiving cobalt chromium everolimus–eluting stents remains controversial. We sought to examine the relationship between DAPT discontinuation and stent thrombosis (ST) after cobalt chromium everolimus-eluting stents. Methods and Results— Outcomes from 11 219 patients were pooled from 3 randomized trials and 4 registries with 2-year follow-up period after cobalt chromium everolimus–eluting stent implantation. Rates of definite/probable ST were analyzed according to DAPT discontinuation in the following time intervals: 0 to 30, 30 to 90, 90 to 180, 180 to 365, and 365 to 730 days. Eighty-five cases of ST (0.75%) occurred in 83 patients during 2 years, with 41 (48.2%) events occurring within 30 days. The 2-year ST rate in patients interrupting DAPT at any time was similar to that in patients never interrupting DAPT through 2 years (25/4067 [0.63%] versus 58/7152 [0.83%] respectively; P =0.27]. By propensity and DAPT usage–adjusted multivariable analysis, permanent DAPT discontinuation before 30 days was independently associated with the occurrence of ST (hazard ratio [95% confidence interval], 26.8 [8.4–85.4]; P <0.0001), whereas permanent DAPT discontinuation in any interval after 90 days was not associated with ST. Only 2 ST events occurred after DAPT discontinuation between 30 and 90 days (both between 30 and 60 days), and the association between permanent DAPT discontinuation and ST during this period is unclear (hazard ratio [95% confidence interval], 8.7 [2.0–37.3]; P =0.004 for adjusted analysis and 3.4 [0.8–13.8]; P =0.07 for the unadjusted analysis). Conclusions— In this large pooled experience, permanent DAPT discontinuation before 30 days after cobalt chromium everolimus–eluting stent implantation was strongly associated with ST, whereas DAPT discontinuation beyond 90 days appeared safe. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00180310, NCT00180479, NCT00307047, NCT00402272, NCT00496938, NCT00676520, and NCT00631228.

Glucocorticoids are highly effective in controlling chronic inflammatory diseases, such as asthma and rheumatoid arthritis, but the exact molecular mechanism of their anti‐inflammatory action remains uncertain. They act by binding to a cytosolic receptor (GR) resulting in activation or repression of gene expression. This may occur via direct binding of the GR to DNA (transactivation) or by inhibition of the activity of transcription factors such as AP‐1 and NF‐κB (transrepression). The topically active steroids fluticasone propionate (EC 50 =1.8×10 −11 M ) and budesonide (EC 50 =5.0×10 −11 M ) were more potent in inhibiting GM‐CSF release from A549 cells than tipredane (EC 50 =8.3×10 −10 M ), butixicort (EC 50 =3.7×10 −8 M ) and dexamethasone (EC 50 =2.2×10 −9 M ). The anti‐glucocorticoid RU486 also inhibited GM‐CSF release in these cells (IC 50 =1.8×10 −10 M ). The concentration‐dependent ability of fluticasone propionate (EC 50 =9.8×10 −10 M ), budesonide (EC 50 =1.1×10 −9 M ) and dexamethasone (EC 50 =3.6×10 −8 M ) to induce transcription of the β 2 ‐receptor was found to correlate with GR DNA binding and occurred at 10–100 fold higher concentrations than the inhibition of GM‐CSF release. No induction of the endogenous inhibitors of NF‐κB, IκBα or I‐κBβ, was seen at 24 h and the ability of IL‐1β to degrade and subsequently induce IκBα was not altered by glucocorticoids. The ability of fluticasone propionate (IC 50 =0.5×10 −11 M ), budesonide (IC 50 =2.7×10 −11 M ), dexamethasone (IC 50 =0.5×10 −9 M ) and RU486 (IC 50 =2.7×10 −11 M ) to inhibit a 3×κB was associated with inhibition of GM‐CSF release. These data suggest that the anti‐inflammatory properties of a range of glucocorticoids relate to their ability to transrepress rather than transactivate genes. British Journal of Pharmacology (1999) 127 , 1003–1011; doi: 10.1038/sj.bjp.0702613

Corticosteroid insensitivity (CI) is a major barrier to treating severe asthma. Despite intensive research, the molecular mechanism of CI remains uncertain. The aim of this study was to determine abnormality in corticosteroid action in severe asthma and to identify the molecular mechanism of the long-acting β₂-adrenergic agonists (LABAs) formoterol and salmeterol on restoration of corticosteroid sensitivity in severe asthma in vitro. Peripheral blood mononuclear cells (PBMCs) were obtained from 16 subjects with severe corticosteroid-insensitive asthma, 6 subjects with mild corticosteroid-sensitive asthma, and 11 healthy volunteers. Corticosteroid (dexamethasone) sensitivity was determined on tumor necrosis factor-α (TNF-α)-induced interleukin (IL)-8 production. Glucocorticoid receptor (GR) phosphorylation and kinase phosphorylation were evaluated by immunoprecipitation-Western blotting analysis and kinase phosphorylation array in IL-2/IL-4-treated corticosteroid insensitive model in PBMCs. In vitro corticosteroid sensitivity on TNF-α-induced IL-8 production was significantly lower in patients with severe asthma than in healthy volunteers and patients with mild asthma. This CI seen in severe asthma was associated with reduced GR nuclear translocation and with hyperphosphorylation of GR, which were reversed by LABAs. In IL-2/IL-4-treated PBMCs, LABAs inhibited phosphorylation of Jun-NH₂-terminal kinase and p38 mitogen-activated protein kinase-γ (p38MAPK-γ) as well as GR. In addition, cells with p38MAPK-γ knockdown by RNA interference did not develop CI in the presence of IL-2/IL-4. Furthermore, p38MAPK-γ protein expression was up-regulated in PBMCs from some patients with severe asthma. In conclusion, p38 MAPK-γ activation impairs corticosteroid action and p38 MAPK-γ inhibition by LABAs has potential for the treatment of severe asthma.

The stent is currently taking the lead in the treatment of obstructive coronary artery disease. The interest in this device is not only reflected by the relative number of patients referred for angioplasty and treated with a stent but also by the large number of clinical trials. These can be divided into trials assessing the safety and feasibility of the implantation of second generation or new stents, studies assessing novel treatment strategies and randomized clinical trials. With respect to the latter, they all compare stent implantation with balloon angioplasty. Of major importance will be the comparison of stent implantation with surgical revascularization of obstructive coronary artery disease. The increasing number of therapeutic options, however, confront the physician with the difficult choice and responsibility of selecting the most appropriate treatment. Therefore, systematic and objective evaluation of the available therapeutic approaches by means of appropriately designed trials is imperative. The purpose of this paper is to summarize and to put into perspective the various studies on intracoronary stenting. Distinction is made between observational studies testing a device or evaluating a new concept in intracoronary stenting and randomized clinical trials.