Azithromycin treatment modifies airway and blood gene expression networks in neutrophilic COPD
Ontology highlight
ABSTRACT: Long-term, low dose azithromycin reduces exacerbation frequency in COPD yet the mechanism remains unclear. This study characterises changes to gene expression in patients with neutrophilic COPD in response to long term low dose azithromycin therapy. Patients with neutrophilic COPD (>61% or >162x10^4/mL sputum neutrophils) were randomised to 12 weeks of either azithromycin or placebo treatment. RNA was extracted from sputum and blood collected before (pre) and after (post) treatment.
Project description:Low-dose macrolides are effective therapy in patients with chronic lung infections, but the mechanisms of action are unclear. We compared global gene expression profiles between P.aeruginosa with and without low-dose Azithromycin (AZM) to study why the low-dose macrolide therapy is effective for cystic fibrosis and diffuse panbronchiolitis. Keywords: dose-response
Project description:Azithromycin has been shown to have anti-fibrotic effects on idiopathic lung fibroblasts (IPF). We thus wanted to investigate involved genes and pathways by microarray analysis. We treated normal human lung fibroblasts with Azithromycin (50uM) for 24h and compared them to non-treated samples.
Project description:Microarrays were used to evaluate the effects of azithromycin and an inflammatory stimulus (SMM) on human airway epithelium. Effects of azithromycin treatment were evaluated at 6, 24 and 48 hours. Effects of SMM were evaluated at 6 and 24 hours. In addition, pretreatment with azithromycin was used to evaluate the modulatory effects on SMM-induced inflammation. SMM=supernatant from microcorpulent material from human cystic fibrosis airways. Experiment Overall Design: 10 treatments total, 3-4 samples (patient codes = replicates) per treatment.
Project description:Microarrays were used to evaluate the effects of azithromycin and an inflammatory stimulus (SMM) on human airway epithelium. Effects of azithromycin treatment were evaluated at 6, 24 and 48 hours. Effects of SMM were evaluated at 6 and 24 hours. In addition, pretreatment with azithromycin was used to evaluate the modulatory effects on SMM-induced inflammation. SMM=supernatant from microcorpulent material from human cystic fibrosis airways. Keywords: timecourse, treatment comparisons.
Project description:Chronic obstructive pulmonary disease (COPD) is one of the most prevalent lung diseases, and involves persistent airflow limitation and incorporates both emphysema and chronic bronchitis. Cigarette smoking has been identified as the main risk factor for disease development and progression. In a basic model of COPD, the disease is initiated when the physiologic response mechanisms to cigarette smoke exposure are overwhelmed; for example, because of long-term exposure effects or other aging-related changes. In this parallel-group case-controlled clinical study we asked to what extent the different transitions in a chronic-exposure-to-disease model are reflected in the proteome and cellular transcriptome of induced sputum samples from the lung. For this, we selected 60 age- and gender-matched individuals for each of four study groups: current healthy smokers, current-smoker COPD patients, former smokers, and never smokers (a total of 240 individuals). Induced sputum was collected, the cell-free supernatant was analyzed by quantitative proteomics (isobaric-tag based), and the cellular mRNA fraction was analyzed by microarray-based expression profiling. The sputum proteome of current smokers (healthy or COPD patients) clearly reflected the common physiological responses to smoke exposure, including alterations in mucin/trefoil proteins (e.g., MUC5AC and TFF1/3up-regulation), peptidase regulators (e.g., TIMP1 up-regulation), and a prominent xenobiotic/oxidative stress response (e.g., NQO1 and ALDH3A1 up-regulation). The latter response also was observed in the sputum transcriptome, which additionally demonstrated an immune-related polarization change (toward a M2 signature). The (long-term) former smoker group showed nearly complete reversal of the observable biological effects. Thirteen differentially abundant proteins between the COPD and healthy smoker groups were identified. These abundant proteins included previously reported COPD-associated proteins (e.g., TIMP1 (up-regulation) and APOA1 (down-regulation)) and novel proteins such as C6orf58 and BPIFB1 (LPLUNC1) (both up-regulated in the COPD group compared with the healthy smokers). In summary, our study demonstrates that sputum proteomics/transcriptomics can capture the complex and reversible physiological response to cigarette smoke exposure, which appears to be only slightly modulated in early-stage COPD patients. The study has been registered on ClinicalTrials.gov with identifier NCT01780298.
Project description:Azithromycin binds to the nascent peptide exit tunnel (NPET) close to the peptidyltransferase center (PTC) of the ribosome, which obstructs the NPET and subsequently induces ribosome stalling and depletion of intracellular pools of tRNAs. To understand the mechanism through which azithromycin represses the transcription of mutation promoting genes, we utilized ribosome profiling to analyze azithromycin caused redistribution of ribosomes on the cellular mRNAs. Wild type PA14 was treated with 16 mg/L azithromycin for 3 hours.
Project description:The effects of azithromycin on whole blood gene expression using the nCounter XT human autoimmune profiling panel was assessed in 8 sarcoidosis patients before and after 1 month of azithromycin treatment.
Project description:This study identifies differentially expression genes in the sputum of people with eosinophilic, neutrophilic and paucigranulocytic asthma. A selection of markers identified using this microarray were further validated using qPCR on a wider sample set. Gene expression profiles were generated from induced sputum samples from 47 asthma patients and were grouped by the inflammatory phenotype assigned using sputum cell counts into neutrophilic asthma (n=12), eosinophilic asthma (n=17) and paucigranulocytic asthma (n=18). RNA was extracted, amplified and hybridised to Illumina Sentrix HumanRef-8 Version 2 Expression BeadChips, and genes that were differentially expressed between asthma inflammatory phenotypes were compared.