Pro-inflammatory mediator responses from neonatal airway epithelial cells and early childhood wheeze.

BACKGROUND: Airway epithelial cell (AEC) function differs between children with and without asthma. Here, we associated neonatal AEC function with asthma symptoms at 4 years of age. METHODS: Nasal AEC were collected from neonates within 48 h of birth. Cells were cultured and stimulated with tumor necrosis factor alpha/interleukin-1 beta (TNFα/IL-1ß), lipopolysaccharide (LPS), or house dust mite (HDM). Absolute concentrations of pro-inflammatory mediators in the culture supernatant were quantified and expressed as median [interquartile range] in pg/mg protein. A parent-completed respiratory questionnaire was returned when the child was 4 years old. RESULTS: AEC were successfully cultured in 139 neonates, of whom 120 were contacted at 4 years and 91 (76%) questionnaires were returned. Sixteen children had wheezed ever and 11 had recent wheeze. At birth, when compared to those with no recent wheeze, supernatants from cultured neonatal AEC from the children with recent wheeze had reduced median IL-8 (CXCL8) release after treatment with culture medium alone (P = 0.049), with TNFα/IL-1ß (P < 0.001) and LPS (P = 0.004). Additionally, and when compared to those with no recent wheeze, 4 year olds with recent wheeze had reduced neonatal AEC release of IL-6 (P = 0.013), GMCSF (P = 0.012), and ICAM-1 (P = 0.017) after treatment with TNFα/IL-1ß and reduced release of ICAM-1 (P = 0.038) and RANTES (P = 0.042) after treatment with HDM. CONCLUSIONS: Abnormalities in AEC function are present at birth before the onset of childhood wheeze. The relationship between reduced AEC function at birth and wheeze at 4 years was not exclusive, suggesting that post-natal factors are required for the AEC abnormality to translate into symptoms.

Primary Paediatric Bronchial Airway Epithelial Cell in Vitro Responses to Environmental Exposures.

The bronchial airway epithelial cell (BAEC) is the site for initial encounters between inhaled environmental factors and the lower respiratory system. Our hypothesis was that release of pro inflammatory interleukins (IL)-6 and IL-8 from primary BAEC cultured from children will be increased after in vitro exposure to common environmental factors. Primary BAEC were obtained from children undergoing clinically indicated routine general anaesthetic procedures. Cells were exposed to three different concentrations of lipopolysaccharide (LPS) or house dust mite allergen (HDM) or particulates extracted from side stream cigarette smoke (SSCS). BAEC were obtained from 24 children (mean age 7.0 years) and exposed to stimuli. Compared with the negative control, there was an increase in IL-6 and IL-8 release after exposure to HDM (p ≤ 0.001 for both comparisons). There was reduced IL-6 after higher compared to lower SSCS exposure (p = 0.023). There was no change in BAEC release of IL-6 or IL-8 after LPS exposure. BAEC from children are able to recognise and respond in vitro with enhanced pro inflammatory mediator secretion to some inhaled exposures.

Culture of airway epithelial cells from neonates sampled within 48-hours of birth.

INTRODUCTION: Little is known about how neonatal airway epithelial cell phenotype impacts on respiratory disease in later life. This study aimed to establish a methodology to culture and characterise neonatal nasal epithelial cells sampled from healthy, non-sedated infants within 48 hours of delivery. METHODS: Nasal epithelial cells were sampled by brushing both nostrils with an interdental brush, grown to confluence and sub-cultured. Cultured cells were characterised morphologically by light and electron microscopy and by immunocytochemistry. As an exemplar pro-inflammatory chemokine, IL-8 concentrations were measured in supernatants from unstimulated monolayers and after exposure to IL-1ß/TNF-α or house dust mite extract. RESULTS: Primary cultures were successfully established in 135 (91%) of 149 neonatal samples seeded, with 79% (n  =  117) successfully cultured to passage 3. The epithelial lineage of the cells was confirmed by morphological analysis and immunostaining. Constitutive IL-8 secretion was observed and was upregulated by IL-1ß/TNF-α or house dust mite extract in a dose dependent manner. CONCLUSION: We describe a safe, minimally invasive method of culturing nasal epithelial cells from neonates suitable for functional cell analysis offering an opportunity to study "naïve" cells that may prove useful in elucidating the role of the epithelium in the early origins of asthma and/or allergic rhinitis.

Lack of effect of nitrogen dioxide exposure on heart rate variability in patients with stable coronary heart disease and impaired left ventricular systolic function.

OBJECTIVES: Epidemiological studies of air pollution on cardiovascular health show associations of cardiac mortality and admissions with exposure to nitrogen dioxide (NO(2)) at low concentrations. These associations could be causal or NO(2) could be acting as a surrogate measure for another air pollutant, most likely ultrafine particles. No studies of cardiac susceptibility to acute exposure to NO(2) have been undertaken. METHODS: Randomised controlled exposures to NO(2) (400 ppb for 1 h) and air in subjects with coronary heart disease and impaired left ventricular systolic function not taking ß adrenoceptor blocking drugs. RESULTS: There were no significant changes in heart rate, blood pressure, leucocyte coping capacity or any heart rate variability measure following NO(2) exposure compared with air. CONCLUSION: These findings suggest that NO(2) does not affect heart rate variability at these concentrations (which are high for urban background levels) and in the absence of other pollutants. While a synergistic effect has not been ruled out, these data lend support to the idea that the epidemiological data associating cardiac outcomes with NO(2) are more likely due to an associated pollutant rather than NO(2) itself.

Maternal intake of antioxidant vitamins in pregnancy in relation to maternal and fetal plasma levels at delivery.

The aim of the present study was to test the hypothesis that maternal intake of antioxidant vitamins is associated with maternal and cord plasma levels at delivery. Women were recruited in early pregnancy in Aberdeen Maternity Hospital and habitual diet during pregnancy was assessed by a food-frequency questionnaire mailed at 34 weeks gestation. Blood samples were taken at recruitment (n 1149) and maternal (n 1149) and cord blood samples (n 747) taken at delivery for analyses of vitamins A, C, E and beta-carotene. Maternal plasma levels of vitamin E and beta-carotene at delivery were significantly higher than levels in early pregnancy while levels of vitamins A and C were significantly lower. Positive correlations were observed for maternal levels of all the vitamins between early pregnancy and delivery. At delivery, maternal plasma concentrations of vitamins A, E and beta-carotene were significantly higher than cord levels, while maternal levels of vitamin C were significantly lower. There were significant correlations between maternal and cord plasma concentrations for beta-carotene and vitamin C but not for vitamins A or E. Maternal dietary intakes were positively correlated with maternal plasma levels of vitamins C, E and beta-carotene in early pregnancy, with maternal plasma levels of beta-carotene and vitamin C at delivery and with cord plasma levels of beta-carotene and vitamin C. The results from the present study show that, in this population, maternal diet influences cord plasma levels of beta-carotene and vitamin C, but not vitamins A and E.