BACTERIAL LIPOPOLYSACCHARIDE STIMULATES PHOSPHOLIPID-SYNTHESIS AND PHOSPHATIDYLCHOLINE BREAKDOWN IN CULTURED HUMAN LEUKEMIA MONOCYTIC THP-1 CELLS
BACTERIAL LIPOPOLYSACCHARIDE STIMULATES PHOSPHOLIPID-SYNTHESIS AND PHOSPHATIDYLCHOLINE BREAKDOWN IN CULTURED HUMAN LEUKEMIA MONOCYTIC THP-1 CELLS
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DOI：
10.1016/0020-711x(92)90264-2
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发表时间：
1992-02-01
期刊：
影响因子：
--
通讯作者：
CHU, AJ
中科院分区：
文献类型：
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作者：
CHU, AJ
1. 研究了人白血病单核THP-1细胞中磷脂的新生合成及其分解代谢。放射性标记的前体：[甲基- h -3]氯，[1,2- c -14]乙醇胺和肌醇-[2-H-3]肌醇随时间的变化，很容易被纳入CHCl3-MEOH可提取的脂质部分。由胆碱、乙醇胺和肌醇衍生的放射性标记物分别优先掺入PC、PE和PI组分中。数据表明，在THP-1细胞中发生了重新合成PL的过程，并且cdp -胆碱途径是合成PC的主要途径。细菌内毒素剂量依赖性地刺激放射性标记前体的掺入。PC和PE的合成在20小时内获得了约50%的刺激，而[H-3]肌醇的掺入在4小时内迅速刺激了170%，之后刺激急剧下降。在这三种情况下，LPS并没有改变放射性标记物的分布。在脉冲追踪研究中，用放射性PL预先标记的细胞暴露于LPS （1 μ g/ml）中。在前2小时内，PC的分解增强了约30%，随后在接下来的4小时内观察到受刺激的PC合成。而LPS对PE和pi的水解作用不明显。这些数据表明，LPS对PL合成产生广谱的刺激作用，并在THP-1细胞中通过磷脂酶C/D反应选择性地刺激PC水解。
1. De novo synthesis of phospholipid and its catabolism in human leukemia monocytic THP-1 cells were investigated.2. Radiolabelled precursors: [methyl-H-3]chloride, [1,2-C-14]ethanolamine and myo-[2-H-3]inositol were readily incorporated into CHCl3-MEOH extractable lipid fraction as a function of time.3. The radiolabels derived from choline, ethanolamine and inositol were preferentially incorporated into PC, PE and PI fraction, respectively. The data indicate that de novo PL synthesis takes place, and the CDP-choline pathway is operative as a major pathway for PC synthesized in THP-1 cells.4. Bacterial endotoxin dose-dependently stimulated the incorporation of radiolabelled precursors. Approximately 50% stimulation in PC and PE synthesis was obtained in 20 hr, while the incorporation of [H-3]inositol was rapidly stimulated by 170% within 4 hr, and the stimulation declined drastically thereafter.5. LPS did not alter the radiolabel distribution into PL in any of the three cases.6. In pulse-chase studies, the cells prelabelled with radioactive PL were exposed to LPS (1-mu-g/ml). The breakdown of PC was enhanced about 30% within the first 2 hr followed by a stimulated PC synthesis observed in the next 4 hr. In contrast, LPS did not induce the hydrolysis of PE and PI.7. The data indicate that LPS produces a broad spectrum of stimulatory effects on PL synthesis and selectively stimulates the hydrolysis of PC via phospholipase C/D reaction in THP-1 cells.