Transforming growth factor β (TGF-β) induced differentiation of lung fibroblasts to myofibroblasts is a key event in the pathogenesis of pulmonary fibrosis. This study aimed to evaluate the effect of curcumin on TGF-β induced differentiation of lung fibroblasts to myofibroblasts and explore the underlying mechanism. Mouse lung fibroblasts were cultured and treated with TGF-β2 and curcumin or rosiglitazone. Cell vitality was examined by MTT assay. The secretion of collagen-1 was assessed by ELISA. α smooth muscle actin (α-SMA) was visualized by immunofluorescence technique. The expression of peroxisome proliferator activated receptor γ (PPAR-γ) and platelet derived growth factor R β (PDGFR-β) was detected by PCR and Western blot analysis. We found that curcumin and rosiglitazone inhibited the proliferation and TGF-β induced differentiation of mouse lung fibroblasts. In addition, curcumin and rosiglitazone inhibited collagen-1 secretion and α-SMA expression in mouse lung fibroblasts. Furthermore, curcumin and rosiglitazone upregulated PPAR-γ and downregulated PDGFR-β expression in mouse lung fibroblasts. In conclusion, our study reveals novel mechanism by which curcumin inhibits TGF-β2 driven differentiation of lung fibroblasts to myofibroblasts. Curcumin could potentially be used for effective treatment of pulmonary fibrosis.

Background/Aims: Epithelial to mesenchymal transition (EMT) is a crucial process involved in pulmonary fibrosis. This study aimed to explore the role of histone deacetylases (HDACs) and endoplasmic reticulum (ER) stress in EMT in human lung epithelial cells. Methods: Human lung adenocarcinoma A549 cells were treated with bleomycin and tunicamycin to induce EMT. The proliferation of A549 cells was detected by MTT assay. The expression of HDACs and EMT markers was detected by PCR and Western blot analysis. The secretion of TGF-β1 and collagen I was examined by ELISA. Results: A549 cells switched from a cobblestone-like appearance to an elongated fibroblast like appearance after exposure to tunicamycin or bleomycin, accompanied by increased expression of N-cadherin, α-SMA and Collagen I. Meanwhile, GRP78 was upregulated in A549 cells exposed to tunicamycin or bleomycin. These changes induced by tunicamycin or bleomycin could be abrogated by 4-PBA. Moreover, tunicamycin and bleomycin promoted the expression of HDAC2 and HDAC6, and HDACs inhibitor SAHA abrogated the morphological and biochemical changes in A549 cells. 4-PBA and SAHA inhibited the upregulation of pulmonary fibrosis factors TGF-β1 and IL-32 and the activation of Smad pathway induced by tunicamycin or bleomycin. Conclusions: We provide the first evidence that tunicamycin and bleomycin induce ER stress and EMT in lung epithelial cells via the upregulation of HDACs. HDACs inhibitor could inhibit ER stress induced upregulation of pulmonary fibrosis factors and the activation of Smad pathway. HDACs inhibitors are promising agents for the therapy of pulmonary fibrosis.

The objective of the study is to explore the role of respiratory syncytial virus Toll-like receptor 3 (TLR3)-mediated immune response in the pathogenesis of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). A total of 20 AECOPD patients and 10 normal volunteers were studied. TLR3 was detected by RT-PCR, and respiratory syncytial virus (RSV) was detected by nested RT-PCR. Then, A549 cells were infected by RSV at different time points and at different viral titers. TLR3 mRNA was detected by RT-PCR, the protein of TLR3 and interferon regulatory factor 3 (IRF3) were detected by western blot, and IRF3 protein localization was detected by immunofluorescence. Interferon-β (IFN-β) and interleukin-6 (IL-6) were detected by ELISA. A total of 4 (20%) of the 20 AECOPD patients sampled were infected with RSV. The forced expiratory volume in 1 second (FEV1) percentage was lower in the AECOPD patients infected with RSV compared to those not infected (P = 0.03). The expression of IL-6 in the two groups was diametrically opposite (P = 0.04). The AECOPD group (n = 20) showed an increase in TLR3 mRNA compared with that of the control group (n = 10) (P = 0.02). The RSV-infected AECOPD group (n = 4) showed an obvious increase in TLR3 mRNA compared with that of the control group (P = 0.03). There was a significant correlation between severity of reduction in lung function at exacerbation and the increasing expression of TLR3 in AECOPD patients. The TLR3 signaling pathway was activated in lung epithelial cells. TLR3 mRNA/protein levels were increased in A549 infected with RSV compared with those of the control group. IRF3 protein also increased along with the occurrence of nuclear transfer in A549 infected with RSV. IFN-β and IL-6 were also increased in the RSV-infected A549 cells compared with those of the control (P = 0.00 and 0.00, respectively). Increased TLR3 expression in AECOPD patients is associated with declining lung function. TLR3 may be a risk factor for RSV-infected AECOPD patients.

Background: Image-guided bronchoscopy techniques such as virtual bronchoscopic navigation (VBN) has emerged as a means of assisting in the biopsy of peripheral pulmonary lesions. However, the role of VBN-assisted (VBNA) bronchoscopy in the diagnosing of peripheral pulmonary lesions (PPLs) has not been well established. This meta-analysis investigated the diagnostic yield of VBN-assisted versus non-VBN-assisted (NVBNA) bronchoscopy for PPLs. Methods: PubMed, Embase, Cochrane library, and Web of Sciences databases were searched up to and including August 2020 to identify randomized controlled trials (RCTs) evaluating the performance of VBNA compared with an NVBNA group. Results were expressed as risk ratio (RR) or mean difference (MD) with accompanying 95% confidence interval (CI). Results: Six RCTs with 1626 patients were included. The overall diagnostic rate was similar in the VBNA (74.17%) and NVBNA (69.51%) groups, with risk ratio of 1.07 (95% CI: 0.98–1.17). However, in the VBNA group, the total examination time was significantly shorter (MD = −3.94 min, 95% CI: −6.57 to −1.36; p = 0.003) than in the NVBNA group. VBNA had superior diagnostic yield than NVBNA for PPLs ⩽ 20 mm (RR = 1.18, 95% CI: 1.05–1.32). In addition, diagnostic yield according to nature of lesion, lesion location in the lung lobe, distance from the hilum, bronchus sign and complications were similar between VBNA and NVBNA groups. Conclusion: VBNA bronchoscopy did not increase overall diagnostic yield in patients with PPLs compared with NVBNA bronchoscopy. The superiority of VBNA over NVBNA was evident among patients with PPLs ⩽ 20 mm. Future multicenter RCTs are needed for further investigation. The reviews of this paper are available via the supplemental material section.

Non-invasive strategies for monitoring posttuberculosis (TB) tracheobronchial stenosis (PTTS) are clinically important but currently lacking. Transforming growth factor-β1 (TGF-β1) and procollagen type I N-propeptide (PINP) have been identified as markers of fibrosis. The present study aimed to investigate the clinical significance of serum TGF-β1 and PINP in PTTS. Serum samples were collected from 119 patients with tracheobronchial TB after the condition was treated for at least 6 months (59 patients with airway stenosis and 60 patients with no stenosis). Serum TGF-β1 and PINP levels were measured using ELISA and compared between the groups. Relationships between serum TGF-β1 and PINP levels and clinical characteristics, interventional bronchoscopy and outcomes of airway stenosis were analysed. The correlation between TGF-β1 and PINP, and their diagnostic efficacy for airway stenosis were also analysed. The TGF-β1 and PINP levels in the airway stenosis group were higher than those in the non-stenosis group. Furthermore, airway stenosis with atelectasis or mucus plugging was associated with higher TGF-β1 levels, and airway stenosis with atelectasis, mucus plugging, right main bronchus stenosis or severe airway tracheal stenosis was associated with higher PINP levels. In addition, TGF-β1 and PINP levels increased after interventional bronchoscopy therapy and airway stenosis with recurrent stenosis was associated with higher baseline levels of both markers. Finally, TGF-β1 levels were positively correlated with PINP levels in patients with airway stenosis. The area under the receiver operating characteristic curve of TGF-β1 and PINP for distinguishing airway stenosis from non-stenosis cases was 0.824 (95% CI: 0.748-0.900) and 0.863 (95% CI: 0.796-0.930), respectively. Therefore, TGF-β1 and PINP are potential biomarkers that may be useful for diagnosing and monitoring PTTS.

The mechanisms that underlie long non-coding RNA 00092 (LINC00092) in lung adenocarcinoma (LUAD) remain unclear. In this study, by mining the Cancer Genome Atlas and Gene Expression Omnibus databases and using bioinformatics tools, we try to elucidate the function of LINC00092 in LUAD. The the Cancer Genome Atlas and gene expression Omnibus microarray datasets were used to analyze and evaluate the expression of LINC00092 in LUAD and its clinical significance. Clinical samples were collected and the relative expression level of LINC00092 were identified by quantitative real time polymerase chain reaction. The LINC00092 related genes were identified by Multi Experiment Matrix, The Atlas of ncRNA in Cancer and the database of RNA-Binding Protein specificities. The predicted genes were then sent to the Gene Ontology enrichment and the Kyoto Encyclopedia of Genes and Genomes pathway analysis. The expression of LINC00092 was significantly decreased in LUAD tissues compared to non-tumor tissues (standard mean difference =-1.10, 95% confidence interval: –1.87 to –0.32, P < .001, random). Low expression of LINC00092 was associated with the poor overall survival (hazard ratio = 1.32, 95% confidence interval: 1.08–1.62, P < .05, fixed) and high pathological stage ( P < .05). The relative expression level of LINC00092 in clinical samples were significantly lower in LUAD tissues compared with adjacent normal tissues. ( P < 0.05) 61 LINC00092 related genes were identified; the Kyoto Encyclopedia of Genes and Genomes analysis showed that the most significant signaling pathways were: NF-κB, HIF-1 and ErbB signaling pathways. In this study, we found that the decrease of LINC00092 expression was involved in LUAD tumorigenesis and metastasis, and the depletion of LINC00092 was associated with a poor prognosis in patients with LUAD. The mechanisms that underlie LINC00092 in LUAD might be related to the NF-κB, HIF-1 and ErbB signaling pathways.

Background Lung squamous cell carcinoma (LUSC) is one of the major types of non-small-cell lung cancer. Epigenetic alterations, such as DNA methylation, have been recognized to be closely associated with the tumorigenesis and progression. Material/Methods In this study, we investigated the prognosis subgroups and assessed their correlation with clinical characteristics in LUSC using a methylation array acquired from The Cancer Genome Atlas (TCGA) database. Results A total of 196 DNA methylation sites exhibited a significant association with patient prognosis, and patients were further stratified into 7 prognosis subgroups based upon the consensus clustering. The patients in every subgroup were different in terms of prognosis and TNM stage. In addition, we found these 196 significant methylation sites corresponded to 258 genes. The function enrichment analysis revealed that these 258 genes enriched in biological pathways were closely related to cancers, such as DNA methylation and demethylation, cell cycle DNA replication, regulation of signal transduction by p53 class mediator, and genetic imprinting. Subsequently, we determined the levels of methylation sites in 7 subgroups, and found 24 intra-subgroup-specific methylation sites. Meanwhile, we selected 3 subgroups-specific methylation sites to construct the prognosis model for LUSC patients using multivariate Cox proportional risk regression model analysis. This model can effectively predict the prognosis of LUSC patients. Conclusions Our study identified a new classification of LUSC into 7 prognosis subgroups on the basis of DNA methylation data in TCGA, which demonstrated that molecular subtypes are independent factor for prognosis in LUSC. This may provide a more detailed explanation for LUSC heterogeneity. Additionally, this classification will contribute to discovery of new biomarkers of LUSC and provide more accurate subdivision of LUSC. Furthermore, these specific DNA methylation sites and corresponding genes can serve as biomarkers for early diagnosis, accurate therapy, and prognosis prediction.

Pulmonary fibrosis (PF) is a progressive and lethal disease with poor prognosis. S100A2 plays an important role in the progression of cancer. However, the role of S100A2 in PF has not yet been reported. In this study, we explored the potential role of S100A2 in PF and its potential molecular mechanisms. Increased expression of S100A2 was first observed in lung tissues of PF patients. We found that downregulation of S100A2 inhibited the transforming growth factor-b1 (TGF-b1)-induced epithelial-mesenchymal transition (EMT) in A549 cells. Mechanically, TGF-b1 upregulated b-catenin and the phosphorylation of glycogen synthase kinase-3b, which was blocked by silencing S100A2 in vitro. Furthermore, lithium chloride (activator of the Wnt/b-catenin signaling pathway) effectively rescued S100A2 knockdown-mediated inhibition of EMT in PF. In conclusion, these findings demonstrate that downregulation of S100A2 alleviated PF through inhibiting EMT. S100A2 is a promising potential target for further understanding the mechanism and developing a strategy for the treatment of PF and other EMT-associated diseases.