Adrenomedullin expression in pathogen-challenged oral epithelial cells

Adrenomedullin, a multifunctional peptide, is expressed by many surface epi thelial cells and, previously, we have demonstrated that adrenomedullin has antimicrobial activity. The oral cavity contains an epithelium that is per manently colonized by microflora, yet infections in a host are rare. We exp osed oral keratinocytes to whole. live cells from four microorganisms commo nly isolated from the oral cavity, Porphyromonas gingivalis. Streptococcus mutans, Candida albicans and Eikenella corrodens. There was upregulation of protein and gene expression in these cells in response to bacterial suspen sions. but not with the yeast, Candida albicans. We propose there is a pote ntial role for microbial products in enhancing mucosal defense mechanisms a nd that adrenomedullin participates in the prevention of local infection, t hus contributing to host defense mechanisms. (C) 2001 Elsevier Science Inc. All rights reserved.