PHOSPHATIDYLCHOLINE-PHOSPHOLIPASE-C MEDIATES THE INDUCTION OF NERVE GROWTH-FACTOR IN CULTURED GLIAL-CELLS

Addition of phosphatidylcholine-hydrolyzing phospholipase C (PC-PLC) t o cultured glial cells increased the levels of nerve growth factor (NG F) mRNA and the amount of cell-secreted NGF, The effect of PC-PLC was 2.5 times higher than that elicited by 4 beta-phorbol 12 beta-myristat e 13 alpha-acetate. In cells in which protein kinase C (PKC) was fully inhibited or downregulated, the effect of PC-PLC was reduced - though still evident - and similar to that exerted by sphingosine. Results t hus indicate that PC-PLC induces the synthesis of NGF by glial cells b y a PKC-dependent and PKC-independent mechanisms.