PRETRANSLATIONAL REGULATION BY GLUCOCORTICOID OF FATTY-ACID AND PHOSPHATIDYLCHOLINE SYNTHESIS IN TYPE-II CELLS FROM FETAL-RAT LUNG

Exposure to fibroblast-conditioned cortisol-containing medium increased fatty acid synthase activity and fatty acid synthase, acetyl-CoA carboxylase and ATP citrate lyase mRNA abundance in fetal type II alveolar epithelial cells. Both fibroblast conditioning and cortisol in the medium were required for maximal effect on the mRNA levels, indicating involvement of mesenchymal-epithelial interaction in the cortisol effects. The observed effects provide evidence for an earlier hypothesis that increased activity of CTP:phosphocholine cytidylyltransferase in lung tissue caused by glucocorticoid is due to increased fatty acid synthesis. However, evidence suggesting pre-translational regulation of this enzyme by glucocorticoid was also found.