Protease‐activated receptor 2 mediates interleukin‐8 and intercellular adhesion molecule‐1 expression in response to Aggregatibacter actinomycetemcomitans

Abstract

We investigated the mechanisms by which extracts of Aggregatibacter actinomycetemcomitans affect the inflammatory response in gingival epithelial cells. Human gingival cells (Ca9-22) were cultured in bacterial extracts prepared from A. actinomycetemcomitans ATCC 29522. The cells were pretreated with protease inhibitors or transfected with small interfering RNA (siRNA) specific for protease-activated receptor 2 (PAR-2). The pretreatment of cells with serine protease inhibitors significantly inhibited A. actinomycetemcomitans extract-induced expression of interleukin-8 (IL-8) and intercellular adhesion molecule-1 (ICAM-1) at both the messenger RNA and protein levels. In addition, A. actinomycetemcomitans extract-induced IL-8 and ICAM-1 expression was significantly decreased in PAR-2/siRNA-transfected cells. A. actinomycetemcomitans extract-induced IL-8 and ICAM-1 expression in gingival epithelial cells is mediated by PAR-2.