Potentiation of PGE(2)-mediated cAMP production during neuronal differentiation of human neuroblastoma SK-N-BE(2)C cells

The prostagland in-evoked cAMP production was studied in human neuroblastom a SK-N-BE(2)C cells during neuronal differentiation induced by all-trans re tinoic acid. The incubation with 5 mum all-trains retinoic acid for 4-6 day s promoted neurite outgrowth of cells. After differentiation, prostaglandin E-2 (PGE(2))-induced cAMP production was dramatically increased, whereas f orskolin- and AIF -induced cAMP productions were not changed. The increase reached maximum after 4-days of incubation with all-trans retinoic acid. Th e differentiation caused an increase in the maximal response and a decrease in the half-maximal effective concentration of the PGE(2)-induced cAMP pro duction. In addition, the binding of [3H]PGE(2) to membrane receptors was e nhanced in differentiated cells. However, the order of potency of the vario us prostaglandins (PGE(1) = PGE(2) > PGD2 = PGF2 alpha = PGI(2)) incAMP pro duction did not change during the differentiation, suggesting that mainly E -prostanoid (EP) receptors were involved. Butaprost, an EP2 receptor specif ic agonist, increased the cAMP level in a concentration dependent manner an d had a similar potentiating effect on cAMP production as PGE(2) upon diffe rentiation. Northern blot analysis using the human cDNA probes shows that t he EP2 mRNA level was about seven times higher in differentiated cells, whi le the dopamine P-hydroxylase (DBH) mRNA completely disappeared. Our result s, thus, suggest that elevated gene expression of the prostanoid EP2 recept or results in an increase in the PGE(2)-evoked cAMP production in SK-N-BE(2 )C cells during neuronal differentiation.