About Epituberculosis.

The airway epithelium responds to microbial exposure by altering expression of a variety of genes to increase innate host defense. We aimed to delineate the early transcriptional response in human primary bronchial epithelial cells exposed for 6 h to a mixture of IL-1beta and TNF-alpha or heat-inactivated Pseudomonas aeruginosa. Because molecular mechanisms of epithelial innate host defense are not fully understood, the open-ended expression-profiling technique SAGE was applied to construct gene expression profiles covering 30,000 genes: 292 genes were found to be differentially expressed. Expression of seven genes was confirmed by real-time qPCR. Among differentially expressed genes, four classes or families were identified: keratins, proteinase inhibitors, S100 calcium-binding proteins, and IL-1 family members. Marked transcriptional changes were observed for keratins that form a key component of the cytoskeleton in epithelial cells. Expression of antimicrobial proteinase inhibitors SLPI and elafin was elevated after microbial or cytokine exposure. Interestingly, expression of numerous S100 family members was observed, and eight members, including S100A8 and S100A9, were among the most differentially expressed genes. Differential expression was also observed for the IL-1 family members IL-1beta, IL-1 receptor antagonist, and IL-1F9, a newly discovered IL-1 family member. Clustering of differentially expressed genes into biological processes revealed that the early inflammatory response in airway epithelial cells to IL-1beta-TNF-alpha and P. aeruginosa is characterized by expression of genes involved in epithelial barrier formation and host defense.

Bronchi↗

PubMed2005

Potential difference measurements in the lower airway of children with and without cystic fibrosis.

Nasal potential difference measurements are valuable endpoint assays in clinical studies of novel treatments for cystic fibrosis (CF). Similar measurements made on the lower airway via the bronchoscope have been successful in adults, but have not been reported in children, the group most likely to benefit from such therapies. Here we report the design and validation of a small, single-lumen catheter technique allowing baseline potential difference and chloride secretion to be assessed in the distal airways of children as young as 1 year of age. Tracheal baseline values were significantly higher in children with CF than those without, although this was not the case more distally. In airways between the third and seventh generation, perfusion with a zero chloride solution containing isoprenaline led to a significant change in potential difference in children without CF, whereas no change was seen in those with CF. This measure provided a reliable distinguishing test between the two disease groups. We confirm that invasive bronchoscopic techniques can be performed safely and reliably in small children. Potential difference measurements could form a useful functional endpoint assay for future studies of either the CFTR gene or protein-based therapies in future trials in the pediatric age group.

Bronchi↗