Phenol sulfotransferase activities and localization in human nasal polyp epithelium

Nasal polyp epithelia, which exhibit a wide variation in epithelial cell morphologies, were tested for phenol sulfotransferase (PST) enzymes. Immunohistology revealed little or no detectable PST antigen in normal ciliated pseudostratified epithelia or in simple squamous metaplastic epithelia; however, intense expression was observed in regions of non-ciliated epithelial cell hyperplasia and in squamous epithelial cells overlying such hyperplastic sites. Western blots confirmed the presence of both P-PST (32 kDa) and M-PST (34 kDa) in the tissue extracts. Bimodal distribution of PST activity as a function of 4-nitrophenol concentration was consistent with expression of these two PST isoforms. These results indicate dynamic and epithelial differentiation-dependent expression of human PSTs in the nasal mucosa and suggest that these sulfotransferases can be modulated within human airways in vivo.