Quiescent and Proliferative Fibroblasts Exhibit Differential p300 HAT Activation through Control of 5-Methoxytryptophan Production
Quiescent and Proliferative Fibroblasts Exhibit Differential p300 HAT Activation through Control of 5-Methoxytryptophan Production
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DOI：
10.1371/journal.pone.0088507
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发表时间：
2014-02-11
期刊：
影响因子：
3.7
通讯作者：
Wu, Kenneth K.
中科院分区：
文献类型：
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作者：
Cheng, Huei-Hsuan;Wang, Kai-Hsuan;Wu, Kenneth K.
静止期成纤维细胞具有独特的遗传程序，并表现出不同于增殖期成纤维细胞的高代谢活性。在对炎症刺激的反应中，静止的成纤维细胞比增殖的成纤维细胞更活跃地表达环氧合酶-2和其他促炎基因。潜在的转录机制尚不清楚。在这里，我们发现佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）和细胞因子增加p300组蛋白乙酰转移酶活性在静止成纤维细胞比在增殖成纤维细胞更高的幅度（> 2倍）。在增殖的成纤维细胞中，p300与环氧合酶-2启动子的结合减少。通过超高效液相色谱结合四极杆飞行时间质谱仪和酶免疫分析，我们发现，5-甲氧基色氨酸的生产在增殖的成纤维细胞比静止的成纤维细胞高2-3倍。此外，5-甲氧基色氨酸和它的代谢前体，5-羟色氨酸，静止的成纤维细胞抑制PMA诱导的p300组蛋白乙酰转移酶活性和环氧合酶-2的表达，增殖成纤维细胞的水平。沉默色氨酸羟化酶-1或羟吲哚O-甲基转移酶在增殖的成纤维细胞与siRNA导致的PMA诱导的p300组蛋白乙酰转移酶活性的水平，在静止的成纤维细胞，这是拯救通过添加5-羟色氨酸或5-甲氧基色氨酸的升高。我们的研究结果表明，在静止的成纤维细胞与增殖的成纤维细胞中，稳健的炎症基因表达归因于由于5-甲氧基色氨酸产生的缺陷而导致的不受控制的p300组蛋白乙酰转移酶活化。5-因此，甲氧基色氨酸是用于新抗炎药物开发的潜在有价值的先导化合物。
Quiescent fibroblasts possess unique genetic program and exhibit high metabolic activity distinct from proliferative fibroblasts. In response to inflammatory stimulation, quiescent fibroblasts are more active in expressing cyclooxygenase-2 and other proinflammatory genes than proliferative fibroblasts. The underlying transcriptional mechanism is unclear. Here we show that phorbol 12-myristate 13-acetate (PMA) and cytokines increased p300 histone acetyltransferase activity to a higher magnitude (> 2 fold) in quiescent fibroblasts than in proliferative fibroblasts. Binding of p300 to cyclooxygenase-2 promoter was reduced in proliferative fibroblasts. By ultrahigh-performance liquid chromatography coupled with a quadrupole time of flight mass spectrometer and enzyme-immunoassay, we found that production of 5-methoxytryptophan was 2-3 folds higher in proliferative fibroblasts than that in quiescent fibroblasts. Addition of 5-methoxytryptophan and its metabolic precursor, 5-hydroxytryptophan, to quiescent fibroblasts suppressed PMA-induced p300 histone acetyltransferase activity and cyclooxygenase-2 expression to the level of proliferative fibroblasts. Silencing of tryptophan hydroxylase-1 or hydroxyindole O-methyltransferase in proliferative fibroblasts with siRNA resulted in elevation of PMA-induced p300 histone acetyltransferase activity to the level of that in quiescent fibroblasts, which was rescued by addition of 5-hydroxytryptophan or 5-methoxytryptophan. Our findings indicate that robust inflammatory gene expression in quiescent fibroblasts vs. proliferative fibroblasts is attributed to uncontrolled p300 histone acetyltransferase activation due to deficiency of 5-methoxytryptophan production. 5-methoxytryptophan thus is a potential valuable lead compound for new anti-inflammatory drug development.