Dataset Information

A novel macrolide/fluoroketolide, solithromycin (CEM-101), reverses corticosteroid insensitivity via phosphoinositide 3-kinase pathway inhibition.

ABSTRACT:

Background and purpose

Corticosteroid insensitivity is a major therapeutic problem for some inflammatory diseases including chronic obstructive pulmonary disease (COPD), and it is known to be induced by reduced histone deacetylase (HDAC)-2 activities via activation of the phosphoinositide 3-kinase (PI3K) pathway. The aim of this study is to evaluate effects of a novel macrolide/fluoroketolide, solithromycin (SOL, CEM-101), on corticosteroid sensitivity induced by oxidative stress.

Experimental approach

Corticosteroid sensitivity was determined by IC50/EC50 of dexamethasone (Dex) on TNF-?-induced CXCL8 production in U937 monocytic cell line and peripheral blood mononuclear cells (PBMC) from COPD patients. Activities of HDAC and protein phosphatase 2A (PP2A) were measured by fluorescence-based assay in cells exposed to hydrogen peroxide (H2O2). We also investigated steroid insensitive airway neutrophilia in cigarette smoke exposed mice in vivo.

Key results

SOL (10 ?M) restored Dex sensitivity in PBMC from COPD patients, H2O2-treated U937 cells and phorbol 12-myristate 13-acetate-differentiated U937 cells. In addition, SOL restored HDAC activity with concomitant inhibition of Akt phosphorylation as surrogate marker of PI3K activation. The inhibition of Akt phosphorylation by SOL was due to increased PP2A phosphatase activity, which was reduced in COPD and oxidative stress model. Other known macrolides, such as eryhthromycin, clarithromycin and azithromycin, were significantly less effective in these responses. In cigarette smoke-exposed mice, SOL (100 mg kg(-1), po) showed significant but weak inhibition of neutrophilia, whereas Dex (10 mg kg(-1), p.o.) showed no such effect. However, a combination of SOL and Dex inhibited neutrophilia by over 50%.

Conclusions and implications

SOL has potential as novel therapy for corticosteroid-insensitive diseases such as COPD.

SUBMITTER: Kobayashi Y

PROVIDER: S-EPMC3696326 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature

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Publications

A novel macrolide/fluoroketolide, solithromycin (CEM-101), reverses corticosteroid insensitivity via phosphoinositide 3-kinase pathway inhibition.

Kobayashi Y Y Wada H H Rossios C C Takagi D D Charron C C Barnes P J PJ Ito K K

British journal of pharmacology 20130701 5

<h4>Background and purpose</h4>Corticosteroid insensitivity is a major therapeutic problem for some inflammatory diseases including chronic obstructive pulmonary disease (COPD), and it is known to be induced by reduced histone deacetylase (HDAC)-2 activities via activation of the phosphoinositide 3-kinase (PI3K) pathway. The aim of this study is to evaluate effects of a novel macrolide/fluoroketolide, solithromycin (SOL, CEM-101), on corticosteroid sensitivity induced by oxidative stress.<h4>Exp ...[more]

PMID: 23758162

Similar Datasets

Project description:RationalePatients with chronic obstructive pulmonary disease (COPD) show a poor response to corticosteroids. This has been linked to a reduction of histone deacetylase-2 as a result of oxidative stress and is reversed by theophylline.ObjectivesTo determine the role of phosphoinositide-3-kinase-delta (PI3K-δ) on the development of corticosteroid insensitivity in COPD and under oxidative stress, and as a target for theophylline.MethodsCorticosteroid sensitivity was determined as the 50% inhibitory concentration of dexamethasone on tumor necrosis factor-α-induced interleukin-8 release in peripheral blood mononuclear cells from patients with COPD (n = 17) and compared with that of nonsmoking (n = 8) and smoking (n = 7) control subjects. The effect of theophylline and a selective PI3K-δ inhibitor (IC87114) on restoration of corticosteroid sensitivity was confirmed in cigarette smoke-exposed mice.Measurements and main resultsPeripheral blood mononuclear cells of COPD (50% inhibitory concentration of dexamethasone: 156.8 ± 32.6 nM) were less corticosteroid sensitive than those of nonsmoking (41.2 ± 10.5 nM; P = 0.018) and smoking control subjects (47.5 ± 19.6 nM; P = 0.031). Corticosteroid insensitivity and reduced histone deacetylase-2 activity after oxidative stress were reversed by a non-selective PI3K inhibitor (LY294002) and low concentrations of theophylline. Theophylline was a potent selective inhibitor of oxidant-activated PI3K-δ, which was up-regulated in peripheral lung tissue of patients with COPD. Furthermore, cells with knock-down of PI3K-δ failed to develop corticosteroid insensitivity with oxidative stress. Both theophylline and IC87114, combined with dexamethasone, inhibited corticosteroid-insensitive lung inflammation in cigarette-smoke-exposed mice in vivo.ConclusionsInhibition of oxidative stress dependent PI3K-δ activation by a selective inhibitor or theophylline provides a novel approach to reversing corticosteroid insensitivity in COPD.

Dataset Information

A novel macrolide/fluoroketolide, solithromycin (CEM-101), reverses corticosteroid insensitivity via phosphoinositide 3-kinase pathway inhibition.

Background and purpose

Experimental approach

Key results

Conclusions and implications

Publications

A novel macrolide/fluoroketolide, solithromycin (CEM-101), reverses corticosteroid insensitivity via phosphoinositide 3-kinase pathway inhibition.

Similar Datasets

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