MicroRNA profiling in lung tissue and bronchoalveolar lavage of cigarette smoke-exposed mice and in COPD patients: A translational approach

© 2017 The Author(s). Chronic obstructive pulmonary disease (COPD) is characterized by a progressive airflow limitation and is associated with a chronic inflammatory response in both airways and lungs. microRNAs (miRNAs) are often highly conserved between species and have an intricate role within homeostatic conditions and immune responses. Also, miRNAs are dysregulated in smoking-associated diseases. We investigated the miRNA profile of 523 miRNAs by stem-loop RT-qPCR in lung tissue and cell-free bronchoalveolar lavage (BAL) supernatant of mice exposed to air or cigarette smoke (CS) for 4 or 24 weeks. After 24 weeks of CS exposure, 31 miRNAs were differentially expressed in lung tissue and 78 in BAL supernatant. Next, we correlated the miRNA profiling data to inflammation in BAL and lung, obtained by flow cytometry or ELISA. In addition, we surveyed for overlap with newly assessed miRNA profiles in bronchial biopsies and with previously assessed miRNA profiles in lung tissue and induced sputum supernatant of smokers with COPD. Several miRNAs showed concordant differential expression between both species including miR-31, miR-155, miR-218 and let-7c. Thus, investigating miRNA profiling data in different compartments and both species provided accumulating insights in miRNAs that may be relevant in CS-induced inflammation and the pathogenesis of COPD

A microRNA-21-mediated SATB1/S100A9/NF-κB axis promotes chronic obstructive pulmonary disease pathogenesis.

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The effect of cigarette smoke exposure on the development of inflammation in lungs, gut and joints of TNFΔARE mice

The inflammatory cytokine TNF-alpha is a central mediator in many immune-mediated diseases, such as Crohn's disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is a prominent common risk factor in these TNF-dependent diseases. We exposed TNF Delta ARE mice; in which a systemic TNF-alpha overexpression leads to the development of inflammation; to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs of TNF Delta ARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure, this aggravation was no longer observed. TNF Delta ARE mice have no increases in CD4+ and CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure. In the gut and joints of TNF Delta ARE mice, 2 or 4 weeks of CS exposure did not modulate the development of inflammation. In conclusion, CS exposure does not modulate gut and joint inflammation in TNF Delta ARE mice. The lung responses towards CS in TNF Delta ARE mice however depend on the duration of CS exposure

MicroRNA profiling reveals a role for MicroRNA-218-5p in the pathogenesis of chronic obstructive pulmonary disease

Rationale: Aberrant expression of microRNAs (miRNAs) can have a detrimental role in disease pathogenesis. Objectives: To identify dysregulated miRNAs in lung tissue of patients with chronic obstructive pulmonary disease (COPD). Methods: We performed miRNA and mRNA profiling using high throughput stem-loop reverse-transcriptase quantitative polymerase chain reaction and mRNA microarray, respectively, on lung tissue of 30 patients (screening cohort) encompassing 8 never-smokers, 10 smokers without airflow limitation, and 12 smokers with COPD. Differential expression of miRNA-218-5p (miR-218-5p) was validated by reverse-transcriptase quantitative polymerase chain reaction in an independent cohort of 71 patients, an in vivo murine model of COPD, and primary human bronchial epithelial cells. Localization of miR-218-5p was assessed by in situ hybridization. In vitro and in vivo perturbation of miR-218-5p combined with RNA sequencing and gene set enrichment analysis was used to elucidate its functional role in COPD pathogenesis. Measurements and Main Results: Several miRNAs were differentially expressed among the different patient groups. Interestingly, miR-218-5p was significantly down-regulated in smokers without airflow limitation and in patients with COPD compared with never-smokers. Decreased pulmonary expression of miR-218-5p was validated in an independent validation cohort, in cigarette smoke-exposed mice, and in human bronchial epithelial cells. Importantly, expression of miR-218-5p strongly correlated with airway obstruction. Furthermore, cellular localization of miR-218-5p in human and murine lung revealed highest expression of miR-218-5p in the bronchial airway epithelium. Perturbation experiments with a miR-218-5p mimic or inhibitor demonstrated a protective role of miR-218-5p in cigarette smoke-induced inflammation and COPD. Conclusions: We highlight a role for miR-218-5p in the pathogenesis of COPD

MicroRNA Profiling Reveals a Role for MicroRNA-218-5p in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Aberrant expression of microRNAs (miRNAs) can have a detrimental role in disease pathogenesis.status: publishe

Cigarette smoke-induced mucin expression is increased in βENaC-Tg mice.

<p>mRNA expression of Muc5ac <b>(A)</b> and Muc5b <b>(B)</b> in total lung tissue upon 4 weeks of air or CS exposure. mRNA expression data were normalized for 3 reference genes (Hprt1, Gapdh, Tfrc). n = 6/group. *p<0.05, **p<0.01, ***p<0.001.</p

Goblet cell metaplasia and mucus secretion upon air or CS exposure.

<p><b>(A)</b> Goblet cell count upon 4 weeks of air or CS exposure. n = 8/group. Representative images of goblet cells in airways of CS-exposed WT mice <b>(B)</b> and CS-exposed βENaC-Tg mice <b>(C)</b> upon 4 weeks of CS exposure. Arrows indicate goblet cells. <b>(D)</b> Quantification of PAS+ mucus content in lumen of airways of non-lavaged mice upon 4 weeks of air or CS exposure n = 3/group. Representative image of PAS+ mucus content in airways of CS-exposed WT mice <b>(E)</b> and CS-exposed βENaC-Tg mice <b>(F)</b>. *p<0.05, **p<0.01, ***p<0.001.</p

Effect of CS exposure on lung function in WT and βENaC-Tg mice.

<p>Lung function was determined in WT and βENaC-Tg mice after exposure to air or CS for 4 weeks. <b>(A)</b> Resistance (R) of the entire compartment (airways, tissue and chest wall). <b>(B)</b> Tissue damping (G), related to tissue resistance. <b>(C)</b> Tissue elasticity (H). <b>(D)</b> Static compliance (C_stat). <b>(E)</b> Dynamic compliance (C_dyn). <b>(F)</b> Total lung capacity (TLC). *p<0.05, **p<0.01, ***p<0.001.</p