Role of the IL-33/ST2 axis in cigarette smoke-induced airways remodelling in chronic obstructive pulmonary disease.

Efficient therapy and potential prophylaxis are confounded by current ignorance of the pathogenesis of airway remodelling and blockade in COPD. To explore the role of the IL-33/ST2 axis in cigarette smoke (CS) exposure-induced airways remodelling. C57BL/6, BALB/c and IL-1RL1 -/- mice exposed to CS were used to establish an animal surrogate of COPD (air-exposed=5~8, CS-exposed=6~12). Hallmarks of remodelling were measured in mice. Cigarette smoke extract (CSE)-induced proliferation and protein production in vitro by fibroblasts in the presence of anti-interleukin-33 (anti-IL-33) or hST2 antibodies were measured. Expression of IL-33 and ST2 and other remodelling hallmarks were measured, respectively, in bronchoalveolar lavage fluid (BALF) (controls=20, COPD=20), serum (controls=59, COPD=90) and lung tissue sections (controls=11, COPD=7) from patients with COPD and controls. Wild-type mice exposed to CS elevated expression of hallmarks of tissue remodelling in the lungs and also in the heart, spleen and kidneys, which were significantly abrogated in the IL-1RL1 -/- mice. Fibroblasts exposed to CSE, compared with control, exhibited early cellular translocation of IL-33, accompanied by proliferation and elevated protein synthesis, all inhabitable by blockade of IL-33/ST2 signalling. Expression of IL-33 and ST2 and hallmarks of tissue remodelling were significantly and proportionally elevated in BALF, serum and tissue samples from patients with COPD. Exposure to CS induces remodelling changes in multiple organs. The data support the hypothesis that CS-induced lung collagen deposition is at least partly a result of CS-induced IL-33 translocation and release from local fibroblasts.

Huang Q ，Li CD ，Yang YR ，Qin XF ，Wang JJ ，Zhang X ，Du XN ，Yang X ，Wang Y ，Li L ，Mu M ，Lv Z ，Cui Y ，Huang K ，Corrigan CJ ，Wang W ，Ying S ... -  《-》

Increased Expression of LASI lncRNA Regulates the Cigarette Smoke and COPD Associated Airway Inflammation and Mucous Cell Hyperplasia.

Cigarette smoke (CS) exposure is strongly associated with chronic obstructive pulmonary disease (COPD). In respiratory airways, CS exposure disrupts airway barrier functions, mucous/phlegm production, and basic immune responses of airway epithelial cells. Based on our recent identification of a specific immunomodulatory long noncoding RNA (lncRNA), we investigated its role in CS-induced responses in bronchial airways of cynomolgus macaque model of CS-induced COPD and in former smokers with and without COPD. The lncRNA was significantly upregulated in CS-induced macaque airways and in COPD airways that exhibited higher mucus expression and goblet cell hyperplasia. Experimental models of cells derived from COPD subjects recapitulated the augmented inflammation and mucus expression following the smoke challenge. Blocking of lncRNA expression in cell culture setting suppressed the smoke-induced and COPD-associated dysregulated mucoinflammatory response suggesting that this airway specific immunomodulatory lncRNA may represent a novel target to mitigate the smoke-mediated inflammation and mucus hyperexpression. In conducting airways, CS disrupts airway epithelial functions, mucociliary clearances, and innate immune responses that are primarily orchestrated by human bronchial epithelial cells (HBECs). Mucus hypersecretion and dysregulated immune response are the hallmarks of chronic bronchitis (CB) that is often exacerbated by CS. Notably, we recently identified a long noncoding RNA (lncRNA) antisense to ICAM-1 (LASI) that mediates airway epithelial responses. To investigate the role of LASI lncRNA in CS-induced airway inflammation and mucin hyperexpression in an animal model of COPD, and in HBECs and lung tissues from former smokers with and without COPD. To interrogate LASI lncRNA role in CS-mediated airway mucoinflammatory responses by targeted gene editing. Small airway tissue sections from cynomolgus macaques exposed to long-term mainstream CS, and those from former smokers with and without COPD were analyzed. The structured-illumination imaging, RNA fluorescence in-situ hybridization (FISH), and qRT-PCR were used to characterize lncRNA expression and the expression of inflammatory factors and airway mucins in a cell culture model of CS extract (CSE) exposure using HBECs from COPD (CHBEs) in comparison with cells from normal control (NHBEs) subjects. The protein levels of mucin MUC5AC, and inflammatory factors ICAM-1, and IL-6 were determined using specific ELISAs. RNA silencing was used to block LASI lncRNA expression and lentivirus encoding LASI lncRNA was used to achieve LASI overexpression (LASI-OE). Compared to controls, LASI lncRNA was upregulated in CS-exposed macaques and in COPD smoker airways, correlating with mucus hyperexpression and mucus cell hyperplasia in severe COPD airways. At baseline, the unstimulated CHBEs showed increased LASI lncRNA expression with higher expression of secretory mucin MUC5AC, and inflammatory factors, ICAM-1, and IL-6 compared to NHBEs. CSE exposure of CHBEs resulted in augmented inflammation and mucus expression compared to controls. While RNA silencing-mediated LASI knockdown suppressed the mucoinflammatory response, cells overexpressing LASI lncRNA showed elevated mRNA levels of inflammatory factors. Altogether, LASI lncRNA may represent a novel target to control the smoke-mediated dysregulation in airway responses and COPD exacerbations.

Manevski M ，Devadoss D ，Long C ，Singh SP ，Nasser MW ，Borchert GM ，Nair MN ，Rahman I ，Sopori M ，Chand HS ... -  《-》

Let-7 mediated airway remodelling in chronic obstructive pulmonary disease via the regulation of IL-6.

Myofibroblast differentiation and extracellular matrix (ECM) deposition are observed in chronic obstructive pulmonary disease (COPD). However, the mechanisms of regulation of myofibroblast differentiation remain unclear. We detected let-7 levels in peripheral lung tissues, serum and primary bronchial epithelial cells of COPD patients and cigarette smoke (CS)-exposed mice. IL-6 mRNA was explored in lung tissues of COPD patients and CS-exposed mice. IL-6 protein was detected in cell supernatant from primary epithelial cells by ELISA. We confirmed the regulatory effect of let-7 on IL-6 by luciferase reporter assay. Western blotting assay was used to determine the expression of α-SMA, E-cadherin and collagen I. In vitro, cell study was performed to demonstrate the role of let-7 in myofibroblast differentiation and ECM deposition. Low expression of let-7 was observed in COPD patients, CS-exposed mice and CS extract (CSE)-treated human bronchial epithelial (HBE) cells. Increased IL-6 was found in COPD patients, CS-exposed mice and CSE-treated HBE cells. Let-7 targets and silences IL-6 protein coding genes through binding to 3' untranslated region (UTR) of IL-6. Normal or CSE-treated HBE cells were co-cultured with human embryonic lung fibroblasts (MRC-5 cells). Reduction of let-7 in HBE cells caused myofibroblast differentiation and ECM deposition, while increase of let-7 mimics decreased myofibroblast differentiation phenotype and ECM deposition. We demonstrate that CS reduced let-7 expression in COPD and, further, identify let-7 as a regulator of myofibroblast differentiation through the regulation of IL-6, which has potential value for diagnosis and treatment of COPD.

Di T ，Yang Y ，Fu C ，Zhang Z ，Qin C ，Sai X ，Liu J ，Hu C ，Zheng M ，Wu Y ，Bian T ... -  《-》

Cigarette smoke-induced pulmonary inflammation, but not airway remodelling, is attenuated in chemokine receptor 5-deficient mice.

Bracke KR ，D'hulst AI ，Maes T ，Demedts IK ，Moerloose KB ，Kuziel WA ，Joos GF ，Brusselle GG ... -  《CLINICAL AND EXPERIMENTAL ALLERGY》

Vitamin D deficiency exacerbates COPD-like characteristics in the lungs of cigarette smoke-exposed mice.

Heulens N ，Korf H ，Cielen N ，De Smidt E ，Maes K ，Gysemans C ，Verbeken E ，Gayan-Ramirez G ，Mathieu C ，Janssens W ... -  《RESPIRATORY RESEARCH》