Changes in the cellular distribution of lipocortin-1 (Annexin-1) in C6 glioma cells after exposure to dexamethasone.
Glucocorticoid-induced changes in cellular levels of Lipocortin-1 (LC-1) (Annexin 1) in C6 glioma cells were determined by electrotransfer and immunoblotting techniques. Separate cell protein fractions were prepared to study the influence of the glucocorticoid steroid, dexamethasone, on LC-1 localisation. Cells were grown in steroid-depleted medium and exposed to dexamethasone (10(-8) and 10(-7) M) for 2, 6, and 16 hr. The glucocorticoid-dependent changes in cellular content of LC-1 were both dose- and time-related. Increases above control levels in intracellular and extracellular LC-1 content were detected with the greatest changes occurring at the cell surface. The glucocorticoid-dependent alteration in LC-1 distribution in C6 glioma cells was attenuated by the protein synthesis inhibitor, cycloheximide, indicating the involvement of de novo LC-1 synthesis. The significance of these results is discussed in relation to the current concept that some of the anti-inflammatory effect of glucocorticoids occurs through the action of extracellular LC-1.
McLeod
J D
JD
Department of Pharmacology, School of Pharmacy and Pharmacology, University of Bath, Claverton Down, U.K.
Goodall
A
A
Jelic
P
P
Bolton
C
C
D017305:Annexin A1 / Q000096:biosynthesis*; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005910:Glioma; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D017305:Annexin A1; D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D011500:Protein Synthesis Inhibitors; D003907:Dexamethasone; D003513:Cycloheximide