Unique pathway for cholesterol uptake in fat cells.
Unique pathway for cholesterol uptake in fat cells.
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DOI：
10.1161/01.atv.0000140821.25572.1b
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发表时间：
2004-09
期刊：
影响因子：
--
通讯作者：
S. Fazio;M. Linton
中科院分区：
文献类型：
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作者：
S. Fazio;M. Linton
高密度脂蛋白（HDL）胆固醇递送至细胞的生物学特征主要在肝细胞中进行研究，肝细胞是反向胆固醇转运途径的共同终点。人们早就知道，HDL 胆固醇向肝细胞的输送并不像含载脂蛋白 (apo)B 的脂蛋白那样涉及脂蛋白颗粒的内化和降解，而是基于将胆固醇货物选择性地从颗粒卸载到细胞中。1 随着 BI 型清道夫受体 (SR-BI) 作为肝脏 HDL 受体的发现，2 HDL 胆固醇输送的最终事件已经进展顺利。其特征是：HDL 通过载脂蛋白 AI (apoAI) 与 SR-BI 结合，HDL 的胆固醇酯 (CE) 货物被选择性地卸载到细胞中，在细胞中被运输回形成脂蛋白或进入胆汁，而缺乏脂质的 apoAI 返回循环中进行另一轮外周胆固醇收集。 3 尽管这似乎是外周胆固醇重新分配到负责胆固醇处理的中央器官的系统机制，但替代过程可能会已经发展到特定的非肝细胞类型可以从 HDL 获取所需的胆固醇。请参见第 1669 页 脂肪细胞可能在获取胆固醇方面具有独特性，因为它们自身合成的能力有限。4 这可能是由于优先利用乙酸酯进行脂肪酸合成或胆固醇合成途径中角鲨烯合酶下游酶的效率降低所致。5 此外，膜……
The biologic features of high-density lipoprotein (HDL) cholesterol delivery to the cell have mostly been investigated in hepatocytes, the consensus termination point of the reverse cholesterol transport pathway. It has long been known that the delivery of HDL cholesterol to the hepatocyte does not involve the internalization and degradation of the lipoprotein particle, as is the case for the apolipoprotein (apo)B-containing lipoproteins, but rather it is based on the selective unloading of the cholesterol cargo from the particle into the cell.1 With the discovery that the scavenger receptor type BI (SR-BI) acts as the hepatic HDL receptor,2 the final events of HDL cholesterol delivery have been well characterized: HDL binds to SR-BI through apolipoprotein AI (apoAI), the cholesteryl ester (CE) cargo of HDL is selectively unloaded into the cell where it is trafficked back into forming lipoproteins or into the bile, and the lipid-poor apoAI returns in the circulation for another round of peripheral cholesterol collection.3 Even though this appears to be a systemic mechanism for redistribution of peripheral cholesterol to a central organ in charge of cholesterol disposal, it is possible that alternative processes might have developed so that particular non-hepatic cell types can acquire needed cholesterol from the HDL. See page 1669 Adipocytes might be unique in their need of acquiring cholesterol, because of their limited ability to synthesize their own.4 This can be caused by a preferential utilization of acetate for fatty acid synthesis or reduced efficiency of enzymes downstream of squalene synthase in the pathway of cholesterol synthesis.5 In addition, the membrane …