The transient receptor potential subfamily A member 1 (TRPA1) is a non-selective cation channel implicated in the pathogenesis of several airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Most of the research on TRPA1 focuses on its expression and function in neuronal context; studies investigating non-neuronal expression of TRPA1 are lacking. In the present study, we show functional expression of TRPA1 in human lung fibroblast cells (CCD19-Lu) and human pulmonary alveolar epithelial cell line (A549). We demonstrate TRPA1 expression at both mRNA and protein levels in these cell types. TRPA1 selective agonists like allyl isothiocyanate (AITC), 4-hydroxynonenal (4-HNE), crotonaldehyde and zinc, induced a concentration-dependent increase in Ca+2 influx in CCD19-Lu and A549 cells. AITC-induced Ca+2 influx was inhibited by Ruthenium red (RR), a TRP channel pore blocker, and by GRC 17536, a TRPA1 specific antagonist. Furthermore, we also provide evidence that activation of the TRPA1 receptor by TRPA1 selective agonists promotes release of the chemokine IL-8 in CCD19-Lu and A549 cells. The IL-8 release in response to TRPA1 agonists was attenuated by TRPA1 selective antagonists. In conclusion, we demonstrate here for the first time that TRPA1 is functionally expressed in cultured human lung fibroblast cells (CCD19-Lu) and human alveolar epithelial cell line (A549) and may have a potential role in modulating release of this important chemokine in inflamed airways.

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The suitability of chicken intestine, a poultry processing by-product, as a source of aminopeptidases has been evaluated. To investigate the heterogeneity of the aminopeptidases in the tissue, tissue fractions separated by differential centrifugation and ion exchange chromatography were screened for aminopeptidase activity using twelve different amino acid naphthylamide substrates. The sedimentable fractions obtained by differential centrifugation, although differing in substrate profile, were largely enriched (72-90%) in aminopeptidase activities. However, the enzymes hydrolysing pro-β-naphthylamide largely belonged to the soluble fraction (> 40%). On the basis of their interaction with the ion exchange resins, DEAE and CM Sepharose, six regions of aminopeptidase activity differing in their elution profiles and substrate specificities were identified. Data reveal the presence of a number of aminopeptidases with multiple specificities in chicken intestine which could be used for industrial applications.