ABSTRACT: COPD-Specific Gene Expression Signatures of Alveolar Macrophages as well as Peripheral Blood Monocytes Overlap and Correlate with Lung Function
Project description:COPD-Specific Gene Expression Signatures of Alveolar Macrophages as well as Peripheral Blood Monocytes Overlap and Correlate with Lung Function
Project description:Rationale: Chronic Obstructive Pulmonary Disease (COPD) is considered a chronic inflammatory disease characterized by progressive airflow limitation and also has significant extrapulmonary (systemic) effects that lead to comorbid conditions. Very little is known about the pathomechanism of the disease. Objectives: Among inflammatory cell types, alveolar macrophages appear to have a key role in initiating and/or sustaining disease progression. These cells are derived from peripheral monocytes. Identification of disease and cell type specific gene expression profiles can be revealing and also practically useful in order to diagnose and characterize disease progression and the effect of drug treatment. Methods: We used Affymetrix microarrays to obtain gene expression data of alveolar macrophages and circulating monocytes of COPD and healthy control patients. The microarray results were confirmed by quantitative real-time polymerase chain reaction in multiple patient collections. Measurements and Main Results: We have identified gene sets specifically associated with COPD in alveolar macrophages and also in monocytes. Immune function, responses to stimuli, and cell death related genes appear to be impacted in both cell types. Remarkably, there is an overlapping gene set between the two cell types. Conclusions: Taken together, our data show that COPD-specific gene signatures can be identified and validated, and that the disease also affects peripheral monocytes. Moreover, monocytes and alveolar macrophages carry overlapping gene expression signatures. Our findings further support the notion that altered responsiveness to stimuli is the key characteristic of alveolar macrophages and also of their precursors, peripheral monocytes. Brochoalveolar lavage fluid samples were collected from of COPD and healthy control patients. Alveolar macrophages were isolated using Percoll gradient centrifugation, isolated using CD14+ magnetic beads, and total RNA was extracted using Qiagen RNeasy Kit. The monocyte samples represent a pool of RNA from 5 patients. Total RNA was labeled with biotin and individual samples were hybridized to Affymetrix HG U133A GeneChips. Affymetrix data files were analyzed using GeneSpring 7.3 software. Using a non-parametric statistical test, we compared the gene expression patterns of the COPD and the healthy control patients and identified a set a genes that showed differential expression between the two groups.
Project description:Rationale: Chronic Obstructive Pulmonary Disease (COPD) is considered a chronic inflammatory disease characterized by progressive airflow limitation and also has significant extrapulmonary (systemic) effects that lead to comorbid conditions. Very little is known about the pathomechanism of the disease. Objectives: Among inflammatory cell types, alveolar macrophages appear to have a key role in initiating and/or sustaining disease progression. These cells are derived from peripheral monocytes. Identification of disease and cell type specific gene expression profiles can be revealing and also practically useful in order to diagnose and characterize disease progression and the effect of drug treatment. Methods: We used Affymetrix microarrays to obtain gene expression data of alveolar macrophages and circulating monocytes of COPD and healthy control patients. The microarray results were confirmed by quantitative real-time polymerase chain reaction in multiple patient collections. Measurements and Main Results: We have identified gene sets specifically associated with COPD in alveolar macrophages and also in monocytes. Immune function, responses to stimuli, and cell death related genes appear to be impacted in both cell types. Remarkably, there is an overlapping gene set between the two cell types. Conclusions: Taken together, our data show that COPD-specific gene signatures can be identified and validated, and that the disease also affects peripheral monocytes. Moreover, monocytes and alveolar macrophages carry overlapping gene expression signatures. Our findings further support the notion that altered responsiveness to stimuli is the key characteristic of alveolar macrophages and also of their precursors, peripheral monocytes.
Project description:Chronic obstructive pulmonary disease (COPD) is a common and heterogeneous respiratory disease, the molecular complexity of which remains poorly understood, as well as the mechanisms by which aging and smoking facilitate COPD development. Here, using single-cell RNA sequencing of more than 65,000 cells from COPD and age-stratified control lung tissues of donors with different smoking histories, we identified monocytes, club cells, and macrophages as the most disease-, aging-, and smoking-relevant cell types, respectively. Notably, we found these highly cell-type specific changes under different conditions converged on cellular dysfunction of the alveolar epithelium. Deeper investigations revealed that the alveolar epithelium damage could be attributed to the abnormally activated monocytes in COPD lungs, which could be amplified via exhaustion of club cell stemness as ages. Moreover, the enhanced intercellular communications in COPD lungs as well as the pro-inflammatory interaction between macrophages and endothelial cells indued by smoking could facilitate signaling between monocyte and the alveolar epithelium. Our findings complement the existing model of COPD pathogenesis by emphasizing the contributions of the previously less appreciated cell types, highlighting their candidacy as potential therapeutic targets for COPD.
Project description:Despite their importance in lung health and disease, it remains unknown how human alveolar macrophages develop early in life. In this study we identified the fetal progenitor of human alveolar macrophages. We used microarray to define the gene signatures of human CD14+ blood monocytes (adult AM precursors), CD116+CD64+ fetal liver monocytes, and CD116+CD64- fetal AM precursors.
Project description:Transcription profiling of human peripheral blood monocytes treated with simvastatin reveals it has an anti-inflammatory effect on macrophages via upregulation of Kruppel-like factor-2
Project description:Aim of this project was to examine the global gene expression profiles of mononuclear phagocytes recruited from peripheral blood to the alveolar space following alveolar deposition of the TLR2-ligand Pam3CSK4 in transgenic CX3CR1+/GFP mice. Experiment Overall Design: Alveolar macrophages (AM) and peripheral blood monocytes (PBM) were isolated from broncho-alveolar lavages and from blood, respectively, using FACS. Expression profiles from AM and PBM of the same mice were compared on the same slides. Each labeled RNA sample contained RNA pooled from six individuals. Four pairs of RNA from corresponding AM and PBM pools were hybridized, giving a total amount of 24 individual mice analyzed. Two hybridizations were performed with AM labeled with Cy3 and PBM with Cy5, two hybridizations were performed with swaped dyes.
Project description:Differential profiles from whole genome human expression arrays on monocytes obtained from peripheral blood in COPD was studied and compared with controls. Monocytes were isolated from Controls (Group 1) which included Control Smokers (Group 1A) and Control Never Smokers (Group 1B) and COPD (Group 2) which included COPD Smokers (Group 2A) and COPD ExSmokers (Group 2B). Differential transcriptomic expression associated with (i) Smoking, (ii) COPD, and (iii) cessation of smoking were identified.
Project description:Multiple gene expression studies have been performed separately in peripheral blood, lung, and airway tissues to study COPD. We performed RNA-sequencing gene expression profiling of large-airway epithelium, alveolar macrophage and peripheral blood samples from the same set of COPD cases and controls from the COPDGene study who underwent bronchoscopy at a single center. Using statistical and gene set enrichment approaches, we sought to improve the understanding of COPD by studying gene sets and pathways across these tissues, beyond the individual genomic determinants.