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Regulation of phenol sulfotransferase expression in cultured bovine bronchial epithelial cells by hydrocortisone
Author(s) -
Beckmann Joe D.,
Illig Mary,
Bartzatt Ronald
Publication year - 1994
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041600324
Subject(s) - sulfation , endogeny , chemistry , hydrocortisone , stimulation , biochemistry , microbiology and biotechnology , enzyme , biology , endocrinology
One conjugative pathway for the inactivation of endogenous and exogenous hydroxylated aromatic compounds is catalyzed by phenol (aryl) sulfotransferases (PSTs), which esterify phenolic acceptors with sulfate. The tracheobronchial epithelium is commonly exposed to phenolic drugs and pollutants, and metabolic sulfation and PST activity in this tissue have been previously demonstrated. To determine what factors may control PST expression, extracts of serum‐free, growth factor‐supplemented cultures of bovine bronchial epithelial cells were assayed for PST activity and PST antigen. The most significant finding was dose‐dependent, apparent stimulated expression by hydrocortisone (EC 50 = 4 nM, maximal stimulation at 20 nM). Time‐course experiments, however, revealed progressive loss of PST in the absence of corticosteroid. After decay of extant PST in steroid‐free medium, hydrocortisone reinduced the expression of PST three to fivefold. Western blots using mouse anti‐bovine PST revealed corresponding increases in 32 kDa PST protein levels in response to hydrocortisone. Steady state kinetic analyses indicated apparent K m values of 1—3 μM for 2‐naphthol regardless of culture conditions. These results suggest that detoxification of phenolic compounds by sulfation may be regulated by corticosteroids.