TRPA1 transduces ROS into regulation of lung inflammation induced by cigarettes

Taiwanese scientists explored how lung epithelial TRPA1 transduces extracellular ROS into transcriptional regulation of lung inflammation induced by cigarette smoke (CS). There were three main objectives to conducting the study: to determine whether lung epithelial transmembrane cation channel TRPA1 could be activated upon extracellular ROS increase (simulating CS presence), to investigate how this TRPA1 may regulate activation of NADPH oxidase, which affects intracellular ROS levels and also in turn promotes transcriptional regulation of inflammation-mediating IL-8, and finally, evaluate how crucially involved TRPA1 is in CS-induced lung inflammation. In defining the pathogenic mechanisms accompanying CS-induced lung inflammation, the scientists aim to apply their findings towards development of potential therapies.

For their first two objectives, the scientists used in vitro models of primary human bronchial epithelial cells (HBECs) to test their hypotheses of TRPA1's roles in CS-related lung inflammation. After exposing the HBECs to CS extract (CSE), the scientists assessed the cells' TRPA1s' response by measuring the calcium influx mediated by TRPA1 through use of the Screen Quest Fluo-8 Medium Removal Calcium Assay. Following this step and analysis of the results, the scientists were able to further interpret the signaling pathway that occurred after the event of TRPA1-activated calcium influx. Eventually their findings indicated that HBEC exposure to CSE initiated TRPA1's response, allowing an influx of calcium that in turn activates NADPH oxidase, which consequently raises intracellular ROS level activating signaling pathway ERK, JNK, and NFκB which brings about IL-8, and also increases expression of TRPA1 in the lung tissue.

These approaches to understanding complex mechanisms are best simplified through use of convenient kits such as the Screen Quest Fluo-8 Medium Removal Calcium Assay. The dye featured in this kit is Fluo-8^®, a calcium indicator optimized to streamline cell loading procedures and moreover, emit intense bright and sensitive signals, so that evaluating calcium concentrations is a brief, straightforward task.

References

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1. n-Hsuan Lin, Meng-Han Liu, Hsin-Kuo Ko, Diahn-Warng Perng, Tzong-Shyuan Lee, and Yu Ru Kou, Lung Epithelial TRPA1 Transduces the Extracellular ROS into Transcriptional Regulation of Lung Inflammation Induced by Cigarette Smoke: The Role of Influxed Ca2+, Mediators of Inflammation, vol. 2015, Article ID 148367, 16 pages, 2015. doi:10.1155/2015/148367
2. Screen Quest Fluo-8 Medium Removal Calcium Assay Kit. AAT Bioquest, n.d. Web. 11 July 2016