The association between the anti-inflammatory protein CC10 and smoking status among participants in a chemoprevention trial

Secondary prevention of silicosis and silico-tuberculosis by periodic screening of silica dust exposed workers using serum club cell protein 16 as a proxy marker

BACKGROUND AND OBJECTIVES

Silicosis is a neglected and widely prevalent occupational disease in India and several other countries such as China, South Africa, Brazil, etc. It is an irreversible, incurable, and progressive disease with high morbidity and mortality, which is mostly caused by occupational exposure to silica dusts. Silicosis is usually detected at an advanced stage, when effective intervention is not possible. But early detection appears to be a cost-effective way to control it. There is a need for some suitable biomarker, which could detect silicosis at an early stage for further necessary intervention. This study aimed to estimate the lung damage in silicotic subjects and its relationship with serum CC16 as a proxy marker. The ultimate objective was to explore whether CC16 could be used as a screening tool for early detection of silicosis.

METHODOLOGY

Radiographs of 117 workers having radiological evidences of silicosis were evaluated in accordance with International Labour Organisation (ILO) Classification of chest radiographs and were categorized as mild, moderate, and severe lung damage using a lung damage scoring system, made for the purpose of this study. The concentration of CC16 in serum was determined by enzyme-linked immunosorbent assay.

RESULT

It was observed that serum CC16 values were significantly decreased in relation to increasing lung damage. The mean ± standard deviation (SD) serum CC16 value in mild lung damage group was 8.4 ± 0.87 ng/mL as compared to 4.0 ± 2.10 ng/mL in moderate and 0.7 ± 0.21 ng/mL in high lung damage groups. On the other hand, CC16 value of control (healthy) population was found to be 16.3 ± 3.8 ng/mL.

CONCLUSION

Result of the study concluded that serum CC16 might be used as a periodic screening tool for early detection of silicosis and for it's secondary prevention. It may be viewed as a new approach toward control of silicosis, and an appropriate policy may be adopted.

Consecutive Hypoxia Decreases Expression of NOTCH3, HEY1, CC10, and FOXJ1 via NKX2-1 Downregulation and Intermittent Hypoxia-Reoxygenation Increases Expression of BMP4, NOTCH1, MKI67, OCT4, and MUC5AC via HIF1A Upregulation in Human Bronchial Epithelial Cells

Previous studies have shown that the experimental models of hypoxia-reoxygenation (H/R) mimics the physiological conditions of ischemia-reperfusion and induce oxidative stress and injury in various types of organs, tissues, and cells, both in vivo and in vitro, including human lung adenocarcinoma epithelial cells. Nonetheless, it had not been reported whether H/R affected proliferation, apoptosis, and expression of stem/progenitor cell markers in the bronchial epithelial cells. In this study, we investigated differential effects of consecutive hypoxia and intermittent 24/24-h cycles of H/R on human bronchial epithelial (HBE) cells derived from the same-race and age-matched healthy subjects (i.e., NHBE) and subjects with chronic obstructive pulmonary disease (COPD) (i.e., DHBE). To analyze gene/protein expression during differentiation, both the NHBE and DHBE cells at the 2nd passage were cultured at the air-liquid interface (ALI) in the differentiation medium under normoxia for 3 days, followed by either culturing under hypoxia (1% O₂) for consecutively 9 days and then returning to normoxia for another 9 days, or culturing under 24/24-h cycles of H/R (i.e., 24 h of 1% O₂ followed by 24 h of 21% O₂, repetitively) for 18 days in total, so that all differentiating HBE cells were exposed to hypoxia for a total of 9 days. In both the normal and diseased HBE cells, intermittent H/R significantly increased HIF1A, BMP4, NOTCH1, MKI67, OCT4, and MUC5AC expression, while consecutive hypoxia significantly decreased NKX2-1, NOTCH3, HEY1, CC10, and FOXJ1 expression. Inhibition of HIF1A or NKX2-1 expression by siRNA transfection respectively decreased BMP4/NOTCH1/MKI67/OCT4/MUC5AC and NOTCH3/HEY1/CC10/FOXJ1 expression in the HBE cells cultured under intermittent H/R to the same levels under normoxia. Overexpression of NKX2-1 via cDNA transfection caused more than 2.8-fold increases in NOTCH3, HEY1, and FOXJ1 mRNA levels in the HBE cells cultured under consecutive hypoxia compared to the levels under normoxia. Taken together, our results show for the first time that consecutive hypoxia decreased expression of the co-regulated gene module NOTCH3/HEY1/CC10 and the ciliogenesis-inducing transcription factor gene FOXJ1 via NKX2-1 mRNA downregulation, while intermittent H/R increased expression of the co-regulated gene module BMP4/NOTCH1/MKI67/OCT4 and the predominant airway mucin gene MUC5AC via HIF1A mRNA upregulation.

Systemic biomarkers of inflammation, oxidative stress and tissue injury and repair among waterpipe, cigarette and dual tobacco smokers

BACKGROUND

Waterpipe tobacco (WPT) smoking is associated with deleterious effects on cardio-pulmonary systems which may have adverse repercussions in pathophysiology and progression of chronic lung and cardiovascular diseases. We compared the biomarkers of systemic inflammation, lipid mediators, injury/repair and oxidative stress between groups of non-smokers (NS), exclusive WPT smokers (WPS), exclusive cigarette smokers (CS) and dual WPS and CS (DS).

METHODS

Two cohorts were recruited. Cohort I consisted of WPS (n=12), CS (n=26), DS (n=10) and NS (n=25). Cohort II consisted of WPS (n=33) and NS (n=24). Plasma and urine samples were collected and analysed for various systemic biomarkers.

RESULTS

Compared with NS, plasma levels of inflammatory mediators (interleukin (IL)-6, IL-8, IL1β and tumor necrosis factor-α) were significantly higher in WPS and CS, and were further augmented in DS. Endothelial biomarkers (intracellular adhesion molecule-1, prostaglandin E-2 and metalloproteinase-9) were significantly higher in CS. Most notably, pro-resolving lipid mediator (resolvin E1) and biomarkers of immunity, tissue injury, and repair were significantly lower in WPS and CS. Urinary levels of 8-isoprostane were significantly higher in all smoking groups in cohort I, while 8-isoprostane, myeloperoxidase, receptor for advanced glycation end products (RAGE), En-RAGE and matrix metalloproteinase-9 were significantly higher in all smoking groups in cohort II.

CONCLUSIONS

Biomarkers of inflammation, oxidative stress, immunity, tissue injury and repair were elevated in WPS and CS groups. Furthermore, concurrent use of WPT and cigarettes is more harmful than cigarette or WPT smoking alone. These data may help inform the public and policy-makers about the dangers of WPT smoking and dual use of tobacco products.

Protective role for club cell secretory protein-16 (CC16) in the development of COPD

Club cell secretory protein-16 (CC16) is the major secreted product of airway club cells, but its role in the pathogenesis of chronic obstructive pulmonary disease (COPD) is unclear. We measured CC16 airway expression in humans with and without COPD and CC16 function in a cigarette smoke (CS)-induced COPD murine model. Airway CC16 expression was measured in COPD patients, smokers without COPD and non-smokers. We exposed wildtype (WT) and CC16(-/-)mice to CS or air for up to 6 months, and measured airway CC16 expression, pulmonary inflammation, alveolar septal cell apoptosis, airspace enlargement, airway mucin 5AC (MUC5AC) expression, small airway remodelling and pulmonary function. Smokers and COPD patients had reduced airway CC16 immunostaining that decreased with increasing COPD severity. Exposing mice to CS reduced airway CC16 expression. CC16(-/-) mice had greater CS-induced emphysema, airway remodelling, pulmonary inflammation, alveolar cell apoptosis, airway MUC5AC expression, and more compliant lungs than WT mice. These changes were associated with increased nuclear factor-κB (NF-κB) activation in CC16(-/-) lungs. CS-induced acute pulmonary changes were reversed by adenoviral-mediated over-expression of CC16. CC16 protects lungs from CS-induced injury by reducing lung NF-κB activation. CS-induced airway CC16 deficiency increases CS-induced pulmonary inflammation and injury and likely contributes to the pathogenesis of COPD.

Serum concentrations of club cell secretory protein (Clara) and cancer mortality in adults: a population-based, prospective cohort study

BACKGROUND

Club cell secretory protein (Clara) (CC16) is produced mainly by bronchiolar club cells and has been shown to have protective effects against airway inflammation and oxidative stress from cigarette smoking and related carcinogens. The goal of this study was to establish whether serum CC16 concentrations predict all-cause and cancer-specific mortality in adults.

METHODS

We used data from the population-based Tucson Epidemiological Study of Airway Obstructive Diseases (TESAOD), a prospective cohort study of respiratory health initiated in Tucson, AZ, USA, in 1972, that recruited a multistage stratified cluster sample of non-Hispanic white households. We measured serum CC16 concentrations in cryopreserved serum samples and reviewed vital status up to Jan 1, 2011, through contact with next of kin, collection of death certificates, and searches of the National Death Index. Our primary analysis was the relation of baseline serum CC16 to all-cause mortality or cause-specific mortality risk, analysed by adjusted Cox proportional hazards models.

FINDINGS

1086 TESAOD participants aged 21-70 years at enrolment were eligible for inclusion. Of these, 653 (60%) had died by 2011, and cause of death was ascertained for 649 (99%). When adjusted for sex, age, education, body-mass index, smoking and pack-years, and baseline levels of lung function, serum CC16 concentrations at baseline were inversely associated with mortality risk over the study follow-up. Mortality risk increased for each 1-SD decrease in CC16 (adjusted hazard ratio [HR] 1·16 [95% CI 1·06-1·26]; p=0·0007). For cause-specific mortality, each 1-SD decrease in serum CC16 was associated with an increased risk of dying of cancer (adjusted HR 1·41 [1·19-1·67]; p<0·0001). In the subset of smokers, the corresponding adjusted HR for mortality by lung cancer was 1·52 (1·14-2·03; p=0·004).

INTERPRETATION

Serum CC16 concentrations can predict mortality risk in the general adult population. The excess risk associated with lower CC16 concentrations is predominantly driven by cancer, particularly lung cancer.

FUNDING

National Heart, Lung, and Blood Institute.

Down-regulation of 14-3-3 isoforms and annexin A5 proteins in lung adenocarcinoma induced by the tobacco-specific nitrosamine NNK in the A/J mouse revealed by proteomic analysis

The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent lung carcinogen in the A/J mouse model. Here we identified and validated, using two-dimensional difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry and immunoblotting, proteins that are differentially expressed in the lungs of mice treated with NNK versus vehicle control treatment. We also determined whether protein levels in the lungs of NNK-treated mice could be further modulated by the chemopreventive agent 1,4-phenylenebis(methylene)selenocyanate (p-XSC). The proteins identified in this study are SEC14-like 3, dihydropyrimidinase-like 2, proteasome subunit alpha type 5, annexin A5, 14-3-3 protein isoforms (theta, epsilon, sigma, and zeta), Rho GDP dissociation inhibitor alpha, myosin light polypeptide 6, tubulin-alpha-1, vimentin, Atp5b protein, alpha-1-antitrypsin, and Clara cell 10 kDa protein (CC10). Among those proteins, we demonstrated for the first time that 14-3-3 isoforms (theta, epsilon, and sigma) and annexin A5 were significantly down-regulated in mouse lung adenocarcinoma induced by NNK and were recovered by p-XSC. These proteins are involved in a variety of biological functions that are critical in lung carcinogenesis. Identification of these proteins in surrogate tissue in future studies would be highly useful in early detection of lung adenocarcinoma and clinical chemoprevention trials.

Lack of association of Clara cell 10-kDa protein gene variant with chronic rhinosinusitis in a Chinese Han population

BACKGROUND

Clara cell 10-kDa protein (CC10) is an anti-inflammatory molecule and has been implicated in the involvement of the pathogenesis of asthma and chronic rhinosinusitis (CRS). A single nucleotide polymorphism (SNP) in CC10 gene (A + 38G) was previously shown to be associated with asthma and plasma CC10 levels. The purpose of this study is to examine whether there is an association between the CC10 A + 38G SNP, plasma CC10 levels, and CRS in a central Chinese population of Han nationality.

METHODS

The CC10 A + 38G SNP was analyzed by means of polymerase chain reaction with restriction fragment length polymorphism and plasma CC10 levels were measured using enzyme-linked immunosorbent assay in 220 patients with CRS (90 patients with nasal polyps [NPs] and 130 patients without NPs) and 180 healthy control subjects. Among 220 patients with CRS, 108 patients were atopic subjects. Severity of disease was determined by coronal computed tomography (CT) scan in CRS patients, which was graded according to Lund and Mackay.

RESULTS

The frequency of the A allele was 0.394, which was not significantly higher than the frequencies of other reported ethnic groups except for German. No association between the CC10 A + 38G SNP and CRS, any subgroup of CRS, or CRS severity could be found. Although subjects carrying the AA genotype had a significantly lower plasma CC10 concentration than those carrying the GG and GA genotypes in both CRS and control groups (p = 0.00 for all), no association was found between the plasma CC10 levels and CRS phenotype.

CONCLUSION

The CC10 A + 38G SNP may not exert a substantial influence on the development of CRS in the Chinese Han population.

Molecular signatures associated with transformation and progression to breast cancer in the isogenic MCF10 model

Comparative microarray analyses provided insight into understanding transcript changes during cancer progression; however, a reproducible signature underlying breast carcinogenesis has yet to be little available. We utilized gene expression profiling to define molecular signatures associated with transformation and cancer progression in a series of isogenic human breast cancer cell lines including a normal, benign, noninvasive and invasive carcinoma. Clustering analysis revealed four distinct expression patterns based on upregulation or downregulation patterns. These profiles proved quite useful for describing breast cancer tumorigenesis and invasiveness. Downregulation of TNFSF7, S100A4, S100A7, S100A8, and S100A9 (calcium-binding protein family), and upregulation of kallikrein-5 and thrombospondin-1 were associated with transformation and progression of breast cancer cells. Importantly, downregulation of the genes was reversed by treatment with silencing inhibitors, implying the potential roles of epigenetic inactivation in breast carcinogenesis. Exogenous expressions of S100A8 and S100A9 inhibit growth in benign and noninvasive carcinoma cells, suggesting their negative role in cell proliferation. The data presented here may facilitate the identification and functional analyses of prognostic biomarkers for breast cancer.

Higher levels of the anti-inflammatory protein CC10 are associated with improvement in bronchial dysplasia and sputum cytometric assessment in individuals at high risk for lung cancer

PURPOSE

CC10, a 10-kDa anti-inflammatory protein secreted by bronchiolar Clara cells, is infrequently expressed in non-small cell lung cancer and its overexpression in non-small cell lung cancer cell lines results in a less malignant phenotype. Several lines of evidence have shown that bronchial dysplasia and sputum atypia are predictors of lung cancer. We investigated whether changes in CC10 expression correlate with regression of bronchial dysplasia and/or improvement in sputum abnormalities as measured by image cytometry.

EXPERIMENTAL DESIGN

High-risk smokers enrolled in a chemoprevention trial underwent serial bronchoscopies with biopsies and bronchoalveolar lavage (BAL) collection, sputum assessment by image cytometry, and blood collection. CC10 was measured by competitive ELISA in BAL and plasma. Logistic regression analyses were done to determine the associations between CC10 levels and the improvement in bronchial dysplasia and sputum cytometric assessment.

RESULTS

The net change in the BAL CC10 levels in subjects with improved bronchial lesions or improved sputum cytometry assessment was significantly higher than in those without improvement (P < 0.05). The odds ratio (95% confidence interval) associated with 1-unit increase in CC10 was 2.72 (1.31-5.64) for regression of dysplastic lesions and 2.94 (1.22-7.05) for improvement in sputum cytometry assessment after multivariate adjustment. Plasma CC10 was not significantly associated with either outcome.

CONCLUSIONS

Higher BAL CC10 levels are significantly correlated with regression of bronchial dysplasia and improvement in sputum cytometry assessment in smokers with high lung cancer risk. Whether CC10 levels can predict clinical outcomes among high-risk populations warrants further investigation.

4-(Methylnitrosamino)-I-(3-Pyridyl)-1-Butanone Enhances the Expression of Apolipoprotein A-I and Clara Cell 17-kDa Protein in the Lung Proteomes of Rats Fed a Corn Oil Diet but not a Fish Oil Diet

The nicotine-derived nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the most potent lung carcinogens in rodents. Several epidemiologic studies indicated that the development of lung cancer in smokers is influenced by the type and amount of dietary polyunsaturated fatty acids. A high corn oil diet has been shown to increase lung tumor volume and to decrease tumor latency in rats treated with NNK. In this study, we investigated the effects of dietary polyunsaturated fatty acids in the form of corn oil or fish oil on lung proteomes in F344 rats treated with or without NNK. The fish oil diet contained 17% fish oil and 3% corn oil, and the corn oil diet contained 20% corn oil. Rats were sacrificed after 3 months, and lungs were excised. Whole lung tissue proteins were separated by two-dimensional liquid chromatography, and differentially expressed proteins were identified by trypsin digestion and tandem mass spectrometry. Apolipoprotein A-I and Clara cell 17-kDa protein were overexpressed in the lungs of rats fed corn oil diet, compared with fish oil diet. NNK further enhanced their expression in rats fed corn oil diet; this effect was not observed in animals fed fish oil diet. The results suggest that the elevated levels of apolipoprotein A-I and Clara cell 17-kDa protein may be involved in the development of NNK-induced lung cancer in rats fed a high corn oil diet. Therefore, we propose that both proteins may serve as potential biomarkers in future molecular epidemiologic and clinical chemoprevention intervention studies.