Defu Li

Bone morphogenetic protein 4 inhibits liposaccharide-induced inflammation in the airway.

Bone morphogenetic protein 4 (BMP4) is a multifunctional growth factor that belongs to the TGF‐β superfamily. The role of BMP4 in lung diseases is not fully understood. Here, we demonstrate that BMP4 was upregulated in lungs undergoing lipopolysaccharide (LPS)‐induced inflammation, and in airway epithelial cells treated with LPS or TNF‐α. BMP4 mutant (BMP4+/−) mice presented with more severe lung inflammation in response to LPS or Pseudomonas aeruginosa, and lower bacterial load compared with that in BMP4+/+ mice. Knockdown of BMP4 by siRNA increased LPS and TNF‐α‐induced IL‐8 expression in 16HBE human airway epithelial cells and in primary human bronchial epithelial cells. Similarly, peritoneal macrophages from BMP4+/− mice produced greater levels of TNF‐α and keratinocyte chemoattractant (KC) upon LPS treatment compared with cells from BMP4+/+ mice. Administration of exogenous BMP4 attenuated the upregulation of TNF‐α, IL‐8, or KC induced by LPS and/or TNF‐α in airway epithelial cells, and peritoneal macrophages. Finally, partial deficiency of BMP4 in BMP4+/− mice protected the animals from restrictive lung function reduction upon chronic LPS exposure. These results indicate that BMP4 plays an important anti‐inflammatory role, controlling the strength and facilitating the resolution of acute lung inflammation; yet, BMP4 also contributes to lung function impairment during chronic lung inflammation.

Comparison and evaluation of two different methods to establish the cigarette smoke exposure mouse model of COPD

Animal model of cigarette smoke (CS) –induced chronic obstructive pulmonary disease (COPD) is the primary testing methodology for drug therapies and studies on pathogenic mechanisms of disease. However, researchers have rarely run simultaneous or side-by-side tests of whole-body and nose-only CS exposure in building their mouse models of COPD. We compared and evaluated these two different methods of CS exposure, plus airway Lipopolysaccharides (LPS) inhalation, in building our COPD mouse model. Compared with the control group, CS exposed mice showed significant increased inspiratory resistance, functional residual capacity, right ventricular hypertrophy index, and total cell count in BALF. Moreover, histological staining exhibited goblet cell hyperplasia, lung inflammation, thickening of smooth muscle layer on bronchia, and lung angiogenesis in both methods of CS exposure. Our data indicated that a viable mouse model of COPD can be established by combining the results from whole-body CS exposure, nose-only CS exposure, and airway LPS inhalation testing. However, in our study, we also found that, given the same amount of particulate intake, changes in right ventricular pressure and intimal thickening of pulmonary small artery are a little more serious in nose-only CS exposure method than changes in the whole-body CS exposure method.

A Functional Variant rs6435156C > T in BMPR2 is Associated With Increased Risk of Chronic Obstructive Pulmonary Disease (COPD) in Southern Chinese Population

Backgrounds Bone morphogenetic protein receptor type 2 (BMPR2) signaling is anti-inflammatory. Decreased BMPR2 expression was seen in lung tissue from chronic obstructive pulmonary disease (COPD) patients. Methods The selected single nucleotide polymorphisms (SNPs) in BMPR2 were genotyped with polymerase chain reaction (PCR) ligase detection reaction. The effects of SNPs on gene expression were analyzed with luciferase assays. The mRNA and protein expression levels of BMPR2 in peripheral blood mononuclear cells (PBMCs) from COPD patients were determined by quantitative PCR and western blotting, respectively. Findings Two SNPs, rs6435156C > T and rs1048829G > T in the 3′-untranslated region (3′UTR) of BMPR2 were selected and genotyped in COPD case and healthy control subjects from southern Chinese population. Both of them were found associated with significantly increased COPD risk (adjusted odds ratio [OR] = 1.58 with 95% confidence interval [CI] = 1.14–2.15, P = 0.0056 for rs6435156C > T; adjusted OR = 1.47 and 95% CI = 1.10–1.97, P = 0.0092 for rs1048829G > T). Older age, cigarette smoking, family history of cancer and COPD were all factors that interacted with rs6435156C > T and rs1048829G > T causing increased COPD risk. Cigarette smokers with rs6435156 (CT + TT) or rs1048829 (GT + TT) were more susceptible to COPD than that with the rs6435156CC or rs1048829GG genotypes. In A549 human alveolar epithelial cells, luciferase reporter assays revealed that introduction of 3′UTR of BMPR2 plasmids carrying rs6435156T allele but not rs1048829T led to lower luciferase activity than the wild-type C or G alleles. Comparing to rs6435156CC, treatment with hsa-miR-20a mimics deceased whereas hsa-miR-20a inhibitor restored the luciferase reporter activity in cells transfected with constructs carrying rs6435156TT. BMPR2 mRNA and protein expressions were significantly lower in PBMCs from COPD smokers than that in non-smokers. COPD patients carrying rs6435156T allele had less BMPR2 expression in PBMCs. Interpretation This study demonstrated that both rs6435156C > T and rs1048829G > T variants in BMPR2 contributed to increased susceptibility to COPD. The T variants of rs6435156 increased COPD risk likely by binding with hsa-miR-20a, thus leading to downregulated BMPR2 expression in lung epithelial and immune cells.

Study Design and Interim Outcomes of Guangzhou Institute of Respiratory Disease COPD Biobank.

Abstract Background: GIRD COPD Biobank is a multicenter observational study blood-based database with local characteristics, in order to investigate the causes, risk factors, pathogenesis, prevalence patterns and trends of COPD and promote new pathogenic insights in China. Methods: We enrolled 855 clinically COPD patients and 660 controls with normal lung function. Extensive data collection has been undertaken with questionnaires, clinical measurements, and collection and storage of blood specimens, following Standard Operating Procedures (SOP). All surveys had similar quality controls, supervisions, and training of the investigator team. Results: Since September 2010, a total of 1515 subjects (1116 [73.7%] males; 855 [56.4%] diagnosed with COPD) were enrolled. Analyses of the design and interim results of the GIRD COPD Biobank Study identified patients with COPD were older, lower educational level, a longer history of pack-year smoking, less in kitchen fan usage, X-ray exposure, and history of disease (P < 0.01 for all); Most of the COPD subjects belonged to moderately severe or worse, stratified according to Global Lung Function Initiative (GLI); COPD patients had relatively more co-morbidities than controls; Environmental hazard exposures might be the main contributors to the reported respiratory symptoms; Cold air, haze, and influenza acted the top three factors to induce respiratory symptoms in both COPD cases and controls. Conclusion: The GIRD COPD Biobank Study has the potential to provide substantial novel insights into the genetics, biomarkers, environmental and lifestyle aspects of COPD. It is expected to provide new insights for pathogenesis and the long-term progression of COPD.

Sodium Tanshinone IIA Sulfonate Decreases Cigarette Smoke-Induced Inflammation and Oxidative Stress via Blocking the Activation of MAPK/HIF-1α Signaling Pathway

Aberrant activation of hypoxia-inducible factor (HIF)-1α is frequently encountered and promotes oxidative stress and inflammation in chronic obstructive pulmonary disease (COPD). The present study investigated whether sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA, can mediate its effect through inhibiting HIF-1α–induced oxidative stress and inflammation in cigarette smoke (CS)-induced COPD in mice. Here, we found that STS improved pulmonary function, ameliorated emphysema and decreased the infiltration of inflammatory cells in the lungs of CS-exposed mice. STS reduced CS- and cigarette smoke extract (CSE)-induced upregulation of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the lungs and macrophages. STS also inhibited CSE-induced reactive oxygen species (ROS) production, as well as the upregulation of heme oxygenase (HO)-1, NOX1 and matrix metalloproteinase (MMP)-9 in macrophages. In addition, STS suppressed HIF-1α expression in vivo and in vitro, and pretreatment with HIF-1α siRNA reduced CSE-induced elevation of TNF-α, IL-1β, and HO-1 content in the macrophages. Moreover, we found that STS inhibited CSE-induced the phosphorylation of ERK, p38 MAPK and JNK in macrophages, and inhibition of these signaling molecules significantly repressed CSE-induced HIF-1α expression. It indicated that STS inhibits CSE-induced HIF-1α expression likely by blocking MAPK signaling. Furthermore, STS also promoted HIF-1α protein degradation in CSE-stimulated macrophages. Taken together, these results suggest that STS prevents COPD development possibly through the inhibition of HIF-1α signaling, and may be a novel strategy for the treatment of COPD.

Identification of TRPCs genetic variants that modify risk for lung cancer based on the pathway and two-stage study.

Objective Store operated calcium channels (SOCCs) and Receptor-operated calcium channels (ROCCs) are important pathways participating in regulation of intracellular Ca2 + concentration in various cell types. The purpose of our study is to determine whether genetic variations in key components of SOCCs and ROCCs are associated with lung cancer risk. Methods We identified 236 tagSNPs in 9 key genes related to SOCCs and ROCCs (TRPC1, TRPC3, TRPC4, TRPC6, TRPC7, ORAI1, ORAI2, STIM1, and STIM2) and evaluated their association with lung cancer risk in a two-stage case-control study with a total of 2433 lung cancer cases and 2433 cancer-free controls using Illumina high throughput genotyping platform. Results We found consistently significant associations of TRPC4 rs9547991 and rs978156, and TRPC7 rs11748198 with increased risk of lung cancer among the three kinds of sources of populations (additive model in combined population: adjusted OR = 1.33, 95% CI = 1.11–1.59 for rs9547991; adjusted OR = 1.21, 95% CI = 1.08–1.35 for rs978156; and adjusted OR = 1.28, 95% CI = 1.10–1.47 for rs11748198). When combining the effects of TRPC7 rs11748198, and TRPC4 rs9547991 and rs978156, subjects carrying “≥ 1” variant alleles had a 1.29-fold increased risk of lung cancer (95% CI = 1.15–1.46), compared with those carrying “0” variant allele. Lung cancer risk significantly increased with the increasing number of variant alleles of the three SNPs in a dose-dependent manner (P for trend = 7.2 × 10− 7). Conclusion These findings suggested that TRPC4 rs9547991 and rs978156, and TRPC7 rs11748198 were candidate susceptibility markers for lung cancer in Chinese population. Our study provides the epidemiological evidence supporting a connection between TRPC members and lung cancer risks.

Long non-coding RNA expression patterns in lung tissues of chronic cigarette smoke induced COPD mouse model

Long non-coding RNAs (lncRNAs) have critical regulatory roles in protein-coding gene expression. Aberrant expression profiles of lncRNAs have been observed in various human diseases. In this study, we investigated transcriptome profiles in lung tissues of chronic cigarette smoke (CS)-induced COPD mouse model. We found that 109 lncRNAs and 260 mRNAs were significantly differential expressed in lungs of chronic CS-induced COPD mouse model compared with control animals. GO and KEGG analyses indicated that differentially expressed lncRNAs associated protein-coding genes were mainly involved in protein processing of endoplasmic reticulum pathway, and taurine and hypotaurine metabolism pathway. The combination of high throughput data analysis and the results of qRT-PCR validation in lungs of chronic CS-induced COPD mouse model, 16HBE cells with CSE treatment and PBMC from patients with COPD revealed that NR_102714 and its associated protein-coding gene UCHL1 might be involved in the development of COPD both in mouse and human. In conclusion, our study demonstrated that aberrant expression profiles of lncRNAs and mRNAs existed in lungs of chronic CS-induced COPD mouse model. From animal models perspective, these results might provide further clues to investigate biological functions of lncRNAs and their potential target protein-coding genes in the pathogenesis of COPD.

Hydrogen gas inhalation protects against cigarette smokeinduced COPD development in mice

Background Chronic obstructive pulmonary disease (COPD) is a chronic lung disease with limited treatment options. Hydrogen (H2) has been shown to be anti-oxidative and anti-inflammatory. This study aimed to evaluate the beneficial effects of H2 inhalation on COPD development in mice. Methods A COPD mouse model was established in male C57BL mice by cigarette smoke (CS) exposure. The H2 intervention was administered by atomisation inhalation. Lung functions were assessed by using Buxco lung function measurement system. The inflammatory cells were counted and the levels of IL-6 and KC in BALF were assayed with ELISA. The lung tissue was subjected to H&E or PAS or Massons trichrome stain. Furthermore, 16HBE cells were used to evaluate the effects of H2 on signaling change caused by hydrogen peroxide (H2O2). H2O2 was used to treat 16HBE cells with or without H2 pretreatment. The IL-6 and IL-8 levels in cell culture medium were measured. The levels of phosphorylated ERK1/2 and nucleic NF-κB in lungs and 16HBE cells were determined. Results H2 ameliorated CS-induced lung function decline, emphysema, inflammatory cell infiltration, small-airway remodelling, goblet-cell hyperplasia in tracheal epithelium and activated ERK1/2 and NF-κB in mouse lung. In 16HBE airway cells, H2O2 increased IL-6 and IL-8 secretion in conjunction with ERK1/2 and NF-κB activation. These changes were reduced by H2 treatment. Conclusions These findings demonstrated that H2 inhalation could inhibit CS-induced COPD development in mice, which is associated with reduced ERK1/2 and NF-κB-dependent inflammatory responses.

Limax extract ameliorates cigarette smoke-induced chronic obstructive pulmonary disease in mice

ABSTRACT Chronic obstructive pulmonary disease (COPD) is a chronic, progressive and lethal lung disease with few treatments. Limax, a mollusk with lung, has been widely used to control phlegm and cough in China, yet whether Limax has a positive effect on COPD is unknown. This study investigated the effects of water‐soluble extract from Limax on COPD development and the underlying mechanisms. The results showed that Limax extract improved lung function, relieved emphysema and suppressed the inflammation in the lungs of CS‐challenged mice, as evidenced by diminished release of IL‐6, KC, TNF‐&agr;, IFN‐&ggr;, Muc5AC, IL‐17 and diminished mRNA expression of Muc5B. Moreover, Limax extract also inhibited phosphorylation of P38 and ERK and increased the expression of PPAR&ggr;. More interestingly, Limax extract (0.1 &mgr;g/ml) inhibited CSE‐induced release of IL‐6 in vitro, which was substantially abrogated by heat treatment, and filtrate obtained from the deproteinized Limax extract with the 100 KD ultrafiltration membrane, inhibited the secretion of IL‐6. Taken together, these results suggest that, Limax extract prevents COPD development via inhibition of inflammation and mucus production, thus has a potential preventive and therapeutic application in COPD. HighlightsLimax extract relieved emphysema in CS‐challenged mice.Mechanism of Limax extract on COPD may inhibit inflammation and mucus production.The active indigents in Limax extract are susceptible to heat.Active component might be protein or 50–100 KD polysaccharides.

Establishment and evaluation of chronic obstructive pulmonary disease model by chronic exposure to motor vehicle exhaust combined with lipopolysaccharide instillation

What is the central question of this study? In this study, by using motor vehicle exhaust (MVE) exposure with or without lipopolysaccharide (LPS) instillation, we established, evaluated and compared MVE, LPS and MVE+LPS treatment‐induced chronic obstructive pulmonary disease (COPD) models in mice. What is the main finding and its importance? Our study demonstrated that the combination of chronic exposure to MVE with early LPS instillation can establish a mouse model with some features of COPD, which will allow researchers to investigate the underlying molecular mechanisms linking air pollution and COPD pathogenesis.