Carcinoembryonic cell adhesion molecule 6 in human lung: regulated expression of a multifunctional type II cell protein.

Carcinoembryonic cell adhesion molecule 6 (CEACAM6) is a glycosylated, glycosylphosphatidylinositol (GPI)-anchored protein expressed in epithelial cells of various human tissues. It binds gram-negative bacteria and is overexpressed in cancers, where it is antiapoptotic and promotes metastases. To characterize CEACAM6 expression in developing lung, we cultured human fetal lung epithelial cells and examined responses to differentiation-promoting hormones, adenovirus expressing thyroid transcription factor-1 (TTF-1), and silencing of TTF-1 with small inhibitory RNA.

Surfactant function and composition in premature infants treated with inhaled nitric oxide.

Objectives: We hypothesized that inhaled nitric oxide treatment of premature infants at risk for bronchopulmonary dysplasia would not adversely affect endogenous surfactant function or composition.

Methods: As part of the Nitric Oxide Chronic Lung Disease Trial of inhaled nitric oxide, we examined surfactant in a subpopulation of enrolled infants. Tracheal aspirate fluid was collected at specified intervals from 99 infants with birth weights <1250 g who received inhaled nitric oxide (20 ppm, weaned to 2 ppm) or placebo gas for 24 days.

Hormonal regulation of alveolarization: structure-function correlation.

Background: Dexamethasone (Dex) limits and all-trans-retinoic acid (RA) promotes alveolarization. While structural changes resulting from such hormonal exposures are known, their functional consequences are unclear.

Methods: Neonatal rats were treated with Dex and/or RA during the first two weeks of life or were given RA after previous exposure to Dex.

Lipidomics of cellular and secreted phospholipids from differentiated human fetal type II alveolar epithelial cells.

Maturation of fetal alveolar type II epithelial cells in utero is characterized by specific changes to lung surfactant phospholipids. Here, we quantified the effects of hormonal differentiation in vitro on the molecular specificity of cellular and secreted phospholipids from human fetal type II epithelial cells using electrospray ionization mass spectrometry. Differentiation, assessed by morphology and changes in gene expression, was accompanied by restricted and specific modifications to cell phospholipids, principally enrichments of shorter chain species of phosphatidylcholine (PC) and phosphatidylinositol, that were not observed in fetal lung fibroblasts.

Surfactant composition and function in a primate model of infant chronic lung disease: effects of inhaled nitric oxide.

Bronchopulmonary dysplasia, or chronic lung disease (CLD), of premature infants involves injury from hyperoxia and mechanical ventilation to an immature lung. We examined surfactant and nitric oxide (NO), which are developmentally deficient in premature infants, in the baboon model of developing CLD. Fetuses were delivered at 125 d gestation and were managed for 14 d with ventilation and oxygen prn without (controls) or with inhaled NO at 5 ppm.

Dysfunction of pulmonary surfactant in chronically ventilated premature infants.

Infants of <30 wk gestation often require respiratory support for several weeks and may develop bronchopulmonary dysplasia (BPD), which is associated with long-term pulmonary disability or death in severe cases. To examine the status of surfactant in infants at high risk for BPD, this prospective study analyzed 247 tracheal aspirate samples from 68 infants of 23-30 wk gestation who remained intubated for 7-84 d. Seventy-five percent of the infants had one or more surfactant samples with abnormal function (minimum surface tension 5.

Surfactant protein profile of pulmonary surfactant in premature infants.

Although premature infants are known to be deficient in pulmonary surfactant, there is limited information regarding surfactant protein (SP) composition. To assess the postnatal profile of SPs, tracheal aspirate samples were collected from 35 intubated infants of 23-31 weeks of gestation between 8 and 80 days of age. In 71 large aggregate surfactant samples that had normal in vitro function (minimum surface tension of less than 1 mN/m by pulsating bubble surfactometry), mean +/- SEM contents of SP-A, SP-B, and SP-C (3.