Ahmed A, Shoaibi M A, Plevin R, Smith S K
Centre for Clinical Research in Immunology and Signalling, Medical School, University of Birmingham, Edgbaston, UK.
Cell Signal. 1995 May;7(4):403-9. doi: 10.1016/0898-6568(94)00095-s.
Platelet-activating factor (PAF) has been shown to stimulate phospholipase D (PLD) activity in human endometrium. The effect of 17 beta-oestradiol on PAF- and 12-O-tetradecanoylphorbol 13-acetate (TPA)-evoked PLD activity assayed as an accumulation of [3H]phosphatidylbutanol was examined in [3H]myristic acid labelled in a human endometrial epithelial cell line HEC-1B. TPA stimulated PLD activity in a dose-dependent manner whereas PAF had no significant effect on PLD activity. Following 48 h pretreatment with 100 nM 17 beta-oestradiol, PAF evoked PLD activity while leaving inositol trisphosphate accumulation in myo-[2-3H] inositol-labelled HEC-1B cells unaffected. In the 17 beta-oestradiol-treated cells, TPA-stimulated PLD activity was significantly elevated at 100 nM TPA (P < 0.05) and 1 microM TPA (P < 0.05) compared to responses in the untreated cells, suggesting that 17 beta-oestradiol may upregulate PKC activity. Interestingly, following a 30 min pretreatment of HEC-1B cells with a range of 17 beta-oestradiol concentrations. TPA (10 nM) and PAF (100 nM) stimulated PLD activity. However, TPA-stimulated PLD activity levels fell 10-fold while PAF-mediated PLD activity remained elevated at 10 nM and 100 nM concentrations of 17 beta-oestradiol suggesting a different mechanism of activation. These results indicate that 17 beta-oestradiol can upregulate PAF-induced PLD activity in HEC-1B cells.
血小板活化因子（PAF）已被证明可刺激人子宫内膜中的磷脂酶D（PLD）活性。在用人子宫内膜上皮细胞系HEC-1B标记的[3H]肉豆蔻酸中，检测了17β-雌二醇对PAF和12-O-十四酰佛波醇-13-乙酸酯（TPA）诱发的PLD活性的影响，该活性通过[3H]磷脂酰丁醇的积累来测定。TPA以剂量依赖性方式刺激PLD活性，而PAF对PLD活性无显著影响。用100 nM 17β-雌二醇预处理48小时后，PAF诱发PLD活性，而肌醇-[2-3H]肌醇标记的HEC-1B细胞中三磷酸肌醇的积累不受影响。在17β-雌二醇处理的细胞中，与未处理细胞相比，在100 nM TPA（P<0.05）和1μM TPA（P<0.05）时，TPA刺激的PLD活性显著升高，这表明17β-雌二醇可能上调蛋白激酶C（PKC）活性。有趣的是，用一系列17β-雌二醇浓度对HEC-1B细胞进行30分钟预处理后。TPA（10 nM）和PAF（100 nM）刺激PLD活性。然而，在17β-雌二醇浓度为10 nM和100 nM时，TPA刺激的PLD活性水平下降了10倍，而PAF介导的PLD活性仍保持升高，这表明存在不同的激活机制。这些结果表明，17β-雌二醇可上调HEC-1B细胞中PAF诱导的PLD活性。
