Constitutive expression of prostaglandin endoperoxide G/H synthetase (PGHS)-2 but not PGHS-1 in hum an tracheal epithelial cells in vitro
| Autor: | Rohit Dwivedi, Mark Kester, Ronald W. Walenga, Christopher Statt, Sarah Butcher, Emanuel Coroneos |
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| Rok vydání: | 1996 |
| Předmět: |
Cell type
medicine.medical_treatment Immunoblotting Indomethacin Retinoic acid Biology Biochemistry Isozyme Culture Media Serum-Free Epithelium chemistry.chemical_compound Endocrinology Adrenal Cortex Hormones Complementary DNA medicine Humans Cyclooxygenase Inhibitors Northern blot RNA Messenger Cycloheximide Growth Substances Cells Cultured Nitrobenzenes Messenger RNA Sulfonamides Cyclooxygenase 2 Inhibitors Membrane Proteins Epithelial Cells Blotting Northern Molecular biology In vitro Isoenzymes Trachea chemistry Cyclooxygenase 2 Prostaglandin-Endoperoxide Synthases Cyclooxygenase 1 Tetradecanoylphorbol Acetate Prostaglandin E |
| Zdroj: | Prostaglandins. 52(5) |
| ISSN: | 0090-6980 |
| Popis: | Primary cultures of human tracheal epithelial (HTE) cells cultured in vitro , in defined serum-free media, express prostaglandin endoperoxide G/H synthase (PGHS) activity and produce prostaglandin E 2 (PGE 2 ). In contrast to every other cell type studied to date, HTE cells appear to constitutively express PGHS-2, the ‘inducible’ form of the enzyme, while expressing little or no PGHS-1, the ‘housekeeping’ isoenzyme in vitro. Prostaglandin synthesis in HTE cells was reduced by a selective PGHS-2 inhibitor, N-(2-cyclohexyloyl-4-nitrophenyl] methane-sulfonamide (NS398), with an IC 50 of approximately 1 μM. Immunoblotting and immunoprecipitation of enzymatic activity with isozyme-specific antisera revealed only the PGHS-2 isoform. Full length human cDNA probes detected only PGHS-2 message in Northern blots. Neither PGHS-2 activity nor mRNA levels were dependent on, nor stimulated by peptide growth factors present in the defined serum-free growth medium, or by serum. Prolonged maintenance in the absence of retinoic acid, however, lead to a decline in PGHS activity. Phorbol-myristate acetate (PMA) induced PGHS-2 activity and mRNA and neither PMA-induced, nor constitutive PGHS-2 expression was suppressed by corticosteroids. Actinomycin D-treatment for six hours reduced the PGHS-2 activity and mRNA to only 50% that of untreated cells, suggesting that PGHS-2 mRNA is extremely stable in these cells. HTE cells, at least in vitro , appear unique among prostaglandin-producing cells in that they express PGHS-2, constitutively, independent of regulation by growth factors, serum, or corticosteroids and fail to express PGHS-1 under any culture condition studied. |
| Databáze: | OpenAIRE |
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