Background Patients with severe asthma are at increased risk of exacerbations and lower respiratory tract infections (LRTI). Severe asthma is heterogeneous, encompassing eosinophilic and non-eosinophilic (mainly neutrophilic) phenotypes. Patients with neutropilic airway diseases may benefit from macrolides. Methods We performed a randomised double-blind placebo-controlled trial in subjects with exacerbationprone severe asthma. Subjects received low-dose azithromycin (n=55) or placebo (n=54) as add-on treatment to combination therapy of inhaled corticosteroids and long-acting β 2 agonists for 6 months. The primary outcome was the rate of severe exacerbations and LRTI requiring treatment with antibiotics during the 26-week treatment phase. Secondary efficacy outcomes included lung function and scores on the Asthma Control Questionnaire (ACQ) and Asthma Quality of Life Questionnaire (AQLQ). Results The rate of primary endpoints (PEPs) during 6 months was not significantly different between the two treatment groups: 0.75 PEPs (95% CI 0.55 to 1.01) per subject in the azithromycin group versus 0.81 PEPs (95% CI 0.61 to 1.09) in the placebo group (p=0.682). In a predefined subgroup analysis according to the inflammatory phenotype, azithromycin was associated with a significantly lower PEP rate than placebo in subjects with noneosinophilic severe asthma (blood eosinophilia ≤200/ml): 0.44 PEPs (95% CI 0.25 to 0.78) versus 1.03 PEPs (95% CI 0.72 to 1.48) (p=0.013). Azithromycin significantly improved the AQLQ score but there were no significant between-group differences in the ACQ score or lung function. Azithromycin was well tolerated, but was associated with increased oropharyngeal carriage of macrolide-resistant streptococci. Conclusions Azithromycin did not reduce the rate of severe exacerbations and LRTI in patients with severe asthma. However, the significant reduction in the PEP rate in azithromycin-treated patients with non-eosinophilic severe asthma warrants further study. ClinicalTrials.gov number NCT00760838.
The mitogen-activated protein kinase (MAPK) pathway plays a critical role in Toll-like receptor (TLR) signaling. MAPK phosphatase-1 (MKP-1) inhibits the MAPK pathway and decreases TLR signaling, but the regulation of MKP-1 is not completely understood. We now show that MKP-1 is acetylated, and that acetylation regulates its ability to interact with its substrates and deactivate inflammatory signaling. We found that LPS activates acetylation of MKP-1. MKP-1 is acetylated by p300 on lysine residue K57 within its substrate-binding domain. Acetylation of MKP-1 enhances its interaction with p38, thereby increasing its phosphatase activity and interrupting MAPK signaling. Inhibition of deacetylases increases MKP-1 acetylation and blocks MAPK signaling in wild-type (WT) cells; however, deacetylase inhibitors have no effect in cells lacking MKP-1. Furthermore, histone deacetylase inhibitors reduce inflammation and mortality in WT mice treated with LPS, but fail to protect MKP-1 knockout mice. Our data suggest that acetylation of MKP-1 inhibits innate immune signaling. This pathway may be an important therapeutic target in the treatment of inflammatory diseases.
The synthesis of some new aminoadamantane derivatives is described. The new compounds were evaluated against a wide range of viruses [influenza A H1N1, influenza A H2N2, influenza A H3N2, influenza B, parainfluenza 3, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), thymidine kinase-deficient (TK-) HSV-1, vaccinia, vesicular stomatitis, polio 1, Coxsackie B4, Sindbis, Semliki forest, Reo 1, varicella-zoster virus (VZV), TK- VZV, human cytomegalovirus (HCMV), and human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2)]. Some of them proved markedly active against the influenza A H2N2 (compounds 4a,b, 5a, 6a, and 7a), H3N2 (compounds 5a, 6a, and 7a), and H1N1 (compounds 4b,c and 6d). Since compounds 5a, 6a, and 7a, amantadine, and rimantadine showed the same comparative pattern of potency against influenza strains H2N2, H3N2, and B, it may postulated that they act according to a similar mechanism, with regard to their "amine" effect, on the M2 ion channel of influenza A (H1N1, H2N2, or H3N2). In general, no significant activity was noted with any of the new compounds against any of the other viruses tested, making their activity against influenza virus more specific and striking. Borderline activity was noted with some of the compounds (4b,c, 5a-c, and 8a) against HIV-1.
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