Faculty Bibliography

Introduction: Airway epithelial cell activation in asthma is associated with the production of Th2 promoting cytokines including thymic stromal lymphopoietin (TSLP). TSLP is elevated in lung biopsies of asthmatics, and we have shown upregulation in cultured human bronchial epithelial cells (HBEC) exposed to ambient particulate matter. TSLP genetic variants are associated with asthma. Sputum analysis is a noninvasive method of obtaining specific cells from the lungs in humans and may allow for isolation of HBEC for the analysis of immunomodulatory cytokines. Hypothesis: TSLP expression is increased in HBEC from induced sputum of asthmatic individuals compared to controls. Methods: Adults with asthma and normal volunteers were enrolled between 4/2011-10/2011 at New York University/Bellevue Hospital. Subjects were excluded if they had: current or past (>10 p-y) tobacco history, other lung disease, or current use of inhaled or oral corticosteroids. Asthma cases were included if spirometry demonstrated bronchodilator reversibility or methacholine hyperresponsiveness. Controls were included if spirometry was normal and methacholine challenge was negative. Blood eosinophils, total and allergen-specific IgE and exhaled nitric oxide (FeNO) were routinely obtained. Sputum was induced with hypertonic saline, treated with sputolysin, and processed for cell count and cell differentials. Sputum cells were stained with fluorophore-labeled monoclonal antibodies, formalin fixed, and discrete cell types detected by FACS. HBEC were identified by size and immunophenotype, isolated by flow sorting, and analyzed (qRT-PCR) for expression of epithelial cell markers and TSLP. Results: Seven subjects successfully underwent sputum induction for analysis (asthma n=4, control n=3). Asthma cases were slightly older than controls (35 vs 30 y) and female predominant (66 vs 50%). There was no significant difference in % predicted FEV₁ between groups but individuals with asthma were more bronchoreactive (8 vs 2% change in FEV₁). FeNO levels and % peripheral eosinophils were higher among asthmatics (52 vs 24 ppb and 3.9 vs 1.4%, respectively). HBEC purity was confirmed by qRT-PCR against cell-specific mRNA. All preparations were positive for epithelial cell markers cytokeratin-7 and E-cadherin and negative for CD11c or CD123 (dendritic and myeloid cell markers). Expression of TSLP but not cytokeratin-7 (normalized against GAPDH from the same isolate) was significantly upregulated in asthma cases compared to controls (4.6-fold, p<0.04). Conclusions: Our data show in situ upregulation of TSLP mRNA in bronchial epithelial cells isolated by multicolor FACS from the induced sputum of individuals with asthma

BACKGROUND: Smokers weigh less and have less body fat than nonsmokers. Increased body fat and weight gain are observed following smoking cessation. To assess a possible molecular mechanism underlying the inverse association between smoking and body weight, we hypothesized that smoking may induce the expression of a fat-depleting gene in the airway epithelium, the cell population that takes the brunt of the stress of cigarette smoke. METHODS: To assess whether smoking up-regulates expression in the airway epithelium of genes associated with weight loss, microarray analysis was used to evaluate genes associated with fat depletion in large airway epithelial samples obtained by fiberoptic bronchoscopy from healthy smokers and healthy nonsmokers. As a candidate gene we further evaluated the expression of alpha(2)-zinc-glycoprotein 1 (AZGP1), a soluble protein that stimulates lipolysis, induces a reduction in body fat in mice, is associated with the cachexia related to cancer, and is known to be expressed in secretory cells of lung epithelium. AZGP1 protein expression was assessed by Western analysis and localization in the large airway epithelium by immunohistochemistry. RESULTS: Both microarray and TaqMan analysis demonstrated that AZGP1 messenger RNA levels were higher in the large airway epithelium of healthy smokers compared to healthy nonsmokers (p < 0.05, all comparisons). Western analysis of airway biopsy specimens from smokers compared with those from nonsmokers demonstrated up-regulation of AZGP1 at the protein level, and immunohistochemical analysis demonstrated up-regulation of AZGP1 in secretory as well as neuroendocrine cells of smokers. CONCLUSIONS: In the context that AZGP1 is involved in lipolysis and fat loss, its overexpression in the airway epithelium of chronic smokers may represent one mechanism for the weight difference in smokers vs nonsmokers

Current classification of pulmonary adenocarcinoma includes noninvasive bronchioloalveolar carcinoma, mixed subtype adenocarcinoma, and several patterns of invasive carcinoma. The extent of invasion in mixed subtype adenocarcinoma is variable, and prior studies suggest that estimates of extent of desmoplasia or invasion and gross tumor size are predictors of survival. Pathologic review of 178 consecutive primary lung adenocarcinoma resections from 1997 to 2000 was performed blinded to outcome. Lymph node metastases were not present in adenocarcinomas with less then 0.6 cm of invasion. In multivariate analysis and in strata adjusted for stage, measurement of linear extent of invasion was significantly associated with survival whereas gross size measurement alone was not. Significant differences in median survival were observed when patients were divided into noninvasive, microinvasive (<0.6 cm invasion), and invasive subcategories. In conclusion, among lung adenocarcinomas, histologic assessment of invasive growth may provide valuable prognostic information, and tumors with invasion under 0.6 cm have a more indolent clinical course after resection