Activation mobilizes the cholesterol in the late endosomes-lysosomes of Niemann Pick type C cells.
Activation mobilizes the cholesterol in the late endosomes-lysosomes of Niemann Pick type C cells.
复制标题
DOI：
10.1371/journal.pone.0030051
复制
发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Steck TL
中科院分区：
文献类型：
--
作者：
Lange Y;Ye J;Steck TL
多种嵌入两亲分子可增加质膜胆固醇的化学活性。为了测试细胞内胆固醇是否可以被类似地激活，我们检查了 NPC1 和 NPC2 成纤维细胞，因为它们在晚期内体和溶酶体 (LE/L) 中积累了大量胆固醇。我们根据其在完整细胞表面的外观来测量细胞内甾醇的流动性，这是通过其对胆固醇氧化酶的敏感性及其与细胞外 2-(羟丙基)-β-环糊精-胆固醇的同位素交换来确定的。这些细胞中的整个细胞质胆固醇池是可移动的，与质膜交换的明显半衰期为~3-4小时，比野生型人类成纤维细胞（半衰期~0.75小时）慢~4-5倍。膜嵌入两性分子氯丙嗪和 1-辛醇增加了细胞内胆固醇的迁移率。氯丙嗪还促进 LE/L 胆固醇净转移至血清和环糊精。令人惊讶的是，用戊二醛或甲醛处理完整的NPC细胞极大地刺激了LE/L胆固醇的流动性。在使用 U18666A 扩展 LE/L 胆固醇池的野生型成纤维细胞中也观察到了类似的效果。我们还表明，固定的野生型成纤维细胞的细胞内膜中的胆固醇是可移动的；它被胆固醇氧化酶迅速氧化，并被外源性甾醇迅速补充。我们的结论是：a) NPC 细胞中的胆固醇可以在几个小时内离开 LE/L（以及其中广泛的膜内含物）； b) 这种流动性是通过嵌入两亲分子激活胆固醇来刺激的； c) 细胞内胆固醇在固定细胞中的流动性更强； d) 激活胆固醇的两性分子可能有助于治疗鼻咽癌疾病。
A variety of intercalating amphipaths increase the chemical activity of plasma membrane cholesterol. To test whether intracellular cholesterol can be similarly activated, we examined NPC1 and NPC2 fibroblasts, since they accumulate large amounts of cholesterol in their late endosomes and lysosomes (LE/L). We gauged the mobility of intracellular sterol from its appearance at the surface of the intact cells, as determined by its susceptibility to cholesterol oxidase and its isotope exchange with extracellular 2-(hydroxypropyl)-β-cyclodextrin-cholesterol. The entire cytoplasmic cholesterol pool in these cells was mobile, exchanging with the plasma membrane with an apparent half-time of ∼3–4 hours, ∼4–5 times slower than that for wild type human fibroblasts (half-time ∼0.75 hours). The mobility of the intracellular cholesterol was increased by the membrane-intercalating amphipaths chlorpromazine and 1-octanol. Chlorpromazine also promoted the net transfer of LE/L cholesterol to serum and cyclodextrin. Surprisingly, the mobility of LE/L cholesterol was greatly stimulated by treating intact NPC cells with glutaraldehyde or formaldehyde. Similar effects were seen with wild type fibroblasts in which the LE/L cholesterol pool had been expanded using U18666A. We also showed that the cholesterol in the intracellular membranes of fixed wild-type fibroblasts was mobile; it was rapidly oxidized by cholesterol oxidase and was rapidly replenished by exogenous sterol. We conclude that a) the cholesterol in NPC cells can exit the LE/L (and the extensive membranous inclusions therein) over a few hours; b) this mobility is stimulated by the activation of the cholesterol with intercalating amphipaths; c) intracellular cholesterol is even more mobile in fixed cells; and d) amphipaths that activate cholesterol might be useful in treating NPC disease.
登录
查看更多内容
影响因子：
2.9
作者：
Ahn, KW;Sampson, NS
通讯作者：
Sampson, NS
影响因子：
4.8
作者：
Lange, Y;Ye, J;Steck, TL
通讯作者：
Steck, TL
影响因子：
4.5
作者：
Jansen, Maurice;Ohsaki, Yuki;Ikonen, Elina
通讯作者：
Ikonen, Elina
影响因子：
6.5
作者：
Abdul-Hammed, Misbaudeen;Breiden, Bernadette;Sandhoff, Konrad
通讯作者：
Sandhoff, Konrad
DOI：
10.1007/978-90-481-8622-8_11
发表时间：
2010-01-01
期刊：
CHOLESTEROL BINDING AND CHOLESTEROL TRANSPORT PROTEINS: STRUCTURE AND FUNCTION IN HEALTH AND DISEASE
影响因子：
--
作者：
Bi, Xiaoning;Liao, Guanghong
通讯作者：
Liao, Guanghong