Histamine regulates cyclooxygenase 2 gene activation through Orai1-mediated NFκB activation in lung cancer cells.
Cell Calcium 2011;
50:27-35. [PMID:
21605904 DOI:
10.1016/j.ceca.2011.04.004]
[Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 04/21/2011] [Accepted: 04/22/2011] [Indexed: 11/22/2022]
Abstract
Histamine, an important chemical mediator, has been shown to regulate inflammation and allergic responses. Stimulation of histamine receptors results in a significant increase in cytoplasmic Ca(2+), which could be mediated by inositol trisphosphate (IP(3))-dependent store-operated Ca(2+) channels (SOC). However, the link between histamine-mediated signaling and activation of inflammatory genes such as cyclooxygenase 2 (COX-2) is still unknown. Our study indicated that the COX-2 protein was highly expressed in human lung cancer cells. Following stimulation with 10 μM of histamine, both store-operated Ca(2+) entry (SOCE) and COX-2 gene expression were evoked. Histamine-mediated COX-2 activation can be prevented by 2-APB and SKF-96365, SOC channel inhibitors. In addition, deletion analysis of the COX-2 promoter suggested that the region between -80 bp and -250 bp, which contains NFκB binding sites, is the key element for histamine-mediated signaling. Knocking down ORAI1, one of the essential molecules of store-operated calcium channels, attenuated histamine-mediated COX-2 expression and NFκB activation. These results indicated that ORAI1-mediated NFκB activation was an important signaling pathway, responsible for transmitting histamine signals that trigger inflammatory reactions.
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