TRPA1 channel expression in non-neuronal cells of the human and mouse respiratory tract.

<p>(<b>A</b>) Total RNAs were extracted from primary small airways epithelial cells (SAEC), human type II alveolar epithelial cells (A549), human primary smooth muscle cells (HBSMC), human embryonic lung fibroblasts (IMR90) and primary normal human lung fibroblasts (NHLF) and relative TRPA1 mRNA amounts were measured by Taqman Real-Time PCR assay. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042454#s2" target="_blank">Results</a> are normalized to the reference gene, β-actin. Each column represents mean ± SEM of n>2 independent experiments. Immunohistochemical analysis of TRPA1 expression in samples taken from human (<b>B</b>) or <i>Trpa1<sup>+/+</sup></i> and <i>Trpa1<sup>−/−</sup></i> mouse airways and lung (<b>C</b>). Representative images of TRPA1 immunostaining show intense staining in epithelial and smooth muscle cells in human tissue. No staining is detected in human samples incubated with the normal serum peptide (Negative control). (<b>C</b>) Incubation with TRPA1 antibody shows a strong staining in epithelial and smooth muscle cells in tissues taken from <i>Trpa1<sup>+/+</sup></i> mice, but not in those from <i>Trpa1<sup>−/−</sup></i> mice. Preadsorption of the TRPA1 antibody with the peptide used for immunization abolished staining (Peptide). Staining for cytokeratin and α-smooth muscle actin (α-SMA) overlaps with the TRPA1 staining in the bronchial epithelium and smooth muscle layer in serial section of human and mice airways/lung tissues (<b>B</b> and <b>C</b>). Scale bar 100 µm.</p>