Cytosolic lipid droplets increase in size by microtubule-dependent complex formation
Cytosolic lipid droplets increase in size by microtubule-dependent complex formation
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DOI：
10.1161/01.atv.0000179676.41064.d4
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发表时间：
2005-09-01
影响因子：
8.7
通讯作者：
Olofsson, SO
中科院分区：
文献类型：
--
作者：
Boström, P;Rutberg, M;Olofsson, SO
目的-含脂肪细胞分化相关蛋白（ADRP）的脂滴在胰岛素抵抗和动脉粥样硬化的发展中起重要作用。这种液滴在无细胞系统中形成，直径为0.1至0.4 μ m，而细胞中存在的液滴大小不同，从小到非常大，这表明液滴在组装后大小可以增加。方法和结果-在NIH 3 T3细胞中的实验表明，脂滴的大小可以增加独立的甘油三酯的生物合成。NIH 3 T3细胞用ADRP-GFP（绿色荧光蛋白）显微注射或用尼罗红染色，然后进行共聚焦显微镜和延时记录。结果表明，脂滴相互形成复合物，其体积等于合并颗粒的总和。复合物的形成可被诺考达唑诱导的微管解聚所抑制，因此，该过程依赖于微管。动力蛋白的存在下，含ADRP液滴支持的作用，这种马达protein.Conclusions -脂滴可以生长后，他们已经组装。这种尺寸的增加与甘油三酯生物合成无关，并且涉及复合物的形成，这需要完整的微管。
Objectives - Adipocyte differentiation- related protein ( ADRP)- containing lipid droplets have an essential role in the development of insulin resistance and atherosclerosis. Such droplets form in a cell-free system with a diameter of 0.1 to 0.4 mu m, while the droplets present in cells vary in size, from small to very large, suggesting that the droplets can increase in size after being assembled. We have addressed this possibility.Methods and Results - Experiments in NIH 3T3 cells demonstrated that the lipid droplets could increase in size independently of triglyceride biosynthesis. NIH 3T3 cells were either microinjected with ADRP - GFP ( green fluorescent protein) or stained with Nile Red and followed by confocal microscopy and time-lapse recordings. The results showed that lipid droplets formed complexes with each other, with a volume equal to the sum of the merging particles. The formation of complexes could be inhibited by the nocodazole-induced depolymerization of the microtubules; thus, the process is dependent on microtubules. The presence of dynein on ADRP-containing droplets supports a role for this motor protein.Conclusions - Lipid droplets can grow after they have been assembled. This increase in size is independent of triglyceride biosynthesis and involves formation of complexes, which requires intact microtubules.