Differential generation of high-density lipoprotein by endogenous and exogenous apolipoproteins in cultured fetal rat astrocytes
Differential generation of high-density lipoprotein by endogenous and exogenous apolipoproteins in cultured fetal rat astrocytes
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DOI：
10.1046/j.1471-4159.1999.0722362.x
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发表时间：
1999-06-01
影响因子：
4.7
通讯作者：
Yokoyama, S
中科院分区：
文献类型：
--
作者：
Ito, J;Zhang, LY;Yokoyama, S
大多数外周血细胞产生富含胆固醇的高密度脂蛋白（HDL）与外源性载脂蛋白作为维持细胞胆固醇稳态的机制之一。从胎鼠脑中分离的星形胶质细胞在此反应中表现出独特的行为。与以前的研究结果一致，星形胶质细胞合成载脂蛋白（apo）E，并产生富含胆固醇的前β-HDL样脂蛋白与此apoE，细胞胆固醇和磷脂。当将外源性apoA-I和E添加到培养基中时，它们引起产生额外的HDL和细胞磷脂。有趣的是，除了仅在孵育的最初几个小时内产生相对富含胆固醇的HDL之外，该额外部分的胆固醇非常少。用于该反应的细胞内胆固醇的动员也非常有限，反映了胆固醇掺入HDL中的差。因此，结果证明了大鼠星形胶质细胞中载脂蛋白产生HDL和胆固醇流出的独特特征，内源性载脂蛋白E产生富含胆固醇的HDL，外源性载脂蛋白产生胆固醇贫乏的HDL。这些脂蛋白可能在CNS中胆固醇转运中发挥不同的作用。
Most peripheral cells generate cholesterol-rich high-density lipoprotein (HDL) with exogenous apolipoprotein as one of the mechanisms for the maintenance of cellular cholesterol homeostasis. Astrocytes isolated from fetal rat brain showed a unique behavior in this reaction. Consistent with previous findings, the astrocytes synthesized apolipoprotein (apo) E and generated cholesterol-rich pre-beta-HDL-like lipoprotein with this apoE, and cellular cholesterol and phospholipids. When exogenous apoA-I and E were added to the medium, they caused generation of additional HDL with cellular phospholipid. It is interesting that this additional part was very poor in cholesterol except for the generation of relatively cholesterol-rich HDL only in the initial few hours of the incubation. The mobilization of intracellular cholesterol for this reaction was also very limited, reflecting the poor cholesterol incorporation into the HDL. Thus, the results demonstrated a unique profile of HDL generation and cholesterol efflux by apolipoproteins in rat astrocytes, with endogenous apoE producing cholesterol-rich HDL and exogenous apolipoproteins producing cholesterol-poor HDL. These lipoproteins may play differential roles in cholesterol transport in the CNS.