Hagel-Bradway S, Tatakis D N, Dziak R
Department of Endodontics, School of Dental Medicine, State University of New York, Buffalo 14214.
Calcif Tissue Int. 1991 Apr;48(4):272-7. doi: 10.1007/BF02556379.
Phorbol esters were used to evaluate the putative effect of protein kinase C (PKC) activation on prostaglandin E2 (PGE2)-induced increases in calcium uptake and cAMP production in the human osteoblastic osteosarcoma cell line, Saos-2. The cells were pretreated for 15 min with phorbol myristate acetate (PMA) followed by a 5 min incubation with PGE2. Calcium uptake was measured with 45Ca and cAMP by radioimmunoassay. A significant increase in calcium uptake was noted in the PGE-treated cells compared with controls and preincubation with the PMA caused a significant decrease in this response. Preincubation with PMA also inhibited the PGE2-induced increase in cAMP under identical conditions. The effect of PMA on the cAMP response was not influenced by the addition of a phosphodiesterase inhibitor. PMA had no effect on the basal levels of either calcium uptake or cAMP production. Likewise, the inactive phorbol esters, phorbol 12,13-didecanoate (PDD) and 4 alpha-phorbol 12-myristate, 13-acetate (4 alpha), had no effect on either basal levels of these parameters or on the PGE2-induced increases. These results suggest that PKC is involved in the down-regulation of PGE2-induced increases in calcium uptake and cAMP production in the Saos-2 osteoblastic cell line.
佛波酯用于评估蛋白激酶C（PKC）激活对人成骨骨肉瘤细胞系Saos-2中前列腺素E2（PGE2）诱导的钙摄取增加和环磷酸腺苷（cAMP）生成的假定作用。细胞先用佛波醇肉豆蔻酸酯乙酸酯（PMA）预处理15分钟，然后与PGE2孵育5分钟。用45Ca测量钙摄取，用放射免疫分析法测量cAMP。与对照组相比，PGE处理的细胞中钙摄取显著增加，而预先与PMA孵育导致该反应显著降低。在相同条件下，预先与PMA孵育也抑制了PGE2诱导的cAMP增加。PMA对cAMP反应的影响不受磷酸二酯酶抑制剂添加的影响。PMA对钙摄取或cAMP生成的基础水平没有影响。同样，无活性的佛波酯，佛波醇12,13-二十二酸酯（PDD）和4α-佛波醇12-肉豆蔻酸酯，13-乙酸酯（4α），对这些参数的基础水平或PGE2诱导的增加均无影响。这些结果表明，PKC参与了Saos-2成骨细胞系中PGE2诱导的钙摄取增加和cAMP生成的下调。
