Plasmalogens in rat liver chromatin: New molecules involved in cell proliferation
Plasmalogens in rat liver chromatin: New molecules involved in cell proliferation
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大鼠肝脏染色质中的缩醛磷脂：参与细胞增殖的新分子
DOI：
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发表时间：
2004
影响因子：
5.6
通讯作者：
C. Sartori
中科院分区：
文献类型：
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作者：
E. Albi;S. Cataldi;M. V. Magni;C. Sartori
染色质的一种次要组分，即磷脂组分，由于核内脂质代谢酶（包括磷脂酰胆碱依赖性磷脂酶C活性）的激活，在细胞周期期间发生变化。已知该酶可被磷脂酰胆碱缩醛磷脂（Plg）激活。到目前为止，几乎没有证据表明Plgs存在于细胞核内。我们研究的目的是确定它们是否存在于细胞核中，并在细胞增殖和凋亡期间负责激活磷脂酰胆碱依赖性磷脂酶C。因此，我们分析了肝细胞的整个匀浆、细胞质、细胞核和染色质的Plg组成。使用磷脂酰胆碱和缩醛磷脂酰胆碱作为底物测定磷脂酰胆碱依赖性磷脂酶C活性。我们的研究结果首次表明，Plgs存在于染色质中，并且磷脂酰磷脂酰胆碱比磷脂酰胆碱更能刺激磷脂酰胆碱依赖性磷脂酶C的活性。最后，为了验证这些分子在细胞增殖和凋亡过程中的可能作用，我们使用了喂食环丙贝特的大鼠肝脏，环丙贝特在治疗过程中刺激肝细胞增殖，停药后刺激细胞凋亡。环丙贝特治疗3天后，染色质磷脂酰磷脂酰胆碱以及磷脂酰胆碱依赖性磷脂酶C活性增加。停药后，当肝细胞发生凋亡时，血浆磷脂酰胆碱含量和磷脂酰胆碱依赖性磷脂酶C活性降低。因此，可以得出结论，plamalogens存在于染色质中，并且可能具有调节磷脂酰胆碱依赖性磷脂酶C和细胞周期的功能。© 2004 Wiley利斯公司
A minor component of chromatin, the phospholipid fraction, changes during cell cycle as result of the activation of intranuclear lipid metabolism enzymes including phosphatidylcholine‐dependent phospholipase C activity. It is known that this enzyme may be activated by phosphatidylcholine plasmalogen (Plg). Until now, there has been little evidences for the presence of Plgs inside the nucleus. The aim of our study is to ascertain if they are present in the nucleus and are responsible of the activation of phosphatidylcholine‐dependent phospholipase C during cell proliferation and apoptosis. Therefore, we have analysed the Plg composition of the whole homogenate, cytosol, nuclei and chromatin of hepatocytes. The phosphatidylcholine‐dependent phospholipase C activity was assayed using both phosphatidylcholine and plasmalogenyl‐phosphatidylcholine as substrates. Our results show, for the first time, that Plgs are present in chromatin and the plasmalogenyl‐phosphatidylcholine stimulates the phosphatidylcholine‐dependent phospholipase C activity more than phosphatidylcholine. Finally, in order to verify the possible role of these molecules during cell proliferation and apoptosis, we used liver of rats fed with ciprofibrate which stimulates hepatocytes proliferation during the treatment and, after withdrawal, apoptosis. After 3 days of ciprofibrate treatment, the chromatin plasmalogenyl‐phosphatidylcholine increases as well as the phosphatidylcholine‐dependent phospholipase C activity. After drug withdrawal, when the hepatocytes undergo to apoptosis, the plasmalogenyl‐phosphatidylcholine content together with phosphatidylcholine‐dependent phospholipase C activity decreases. Therefore, it can be concluded that plamalogens are present in the chromatin, and probably may have a function both in regulating phosphatidylcholine dependent phospholipase C and cell cycle. © 2004 Wiley‐Liss, Inc.