Ethanol selectively impairs clathrin-mediated internalization in polarized hepatic cells.
Ethanol selectively impairs clathrin-mediated internalization in polarized hepatic cells.
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DOI：
10.1016/j.bcp.2009.05.012
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发表时间：
2009-09-15
影响因子：
5.8
通讯作者：
Tuma, Pamela L.
中科院分区：
文献类型：
--
作者：
Fernandez, David J.;McVicker, Benita L.;Tuma, Dean J.;Tuma, Pamela L.
尽管酒精性肝病在临床上有很好的描述，但酒精引起的肝毒性的分子基础尚不清楚。先前，我们确定在乙醇处理的wi - b细胞中，网格蛋白介导的asialglycoprotein receptor内化被破坏，而糖磷脂酰肌醇锚定蛋白的内化被认为是通过小泡/筏介导的途径被内吞，这表明网格蛋白介导的内吞作用被乙醇选择性地破坏。为了验证这种可能性，我们在对照和乙醇处理的wi - b细胞中检测了由不同机制内化的一组蛋白质和化合物的内化。我们确定已知通过网格蛋白介导机制内化的标记物的内化受到损害。相比之下，在乙醇处理的细胞中，小泡/筏子介导的内吞作用、液相内化或非囊泡介导的摄取标记物的内化没有受到损害。我们进一步确定，在乙醇处理的细胞中，网格蛋白重链在基底外侧表面的小点上积累，而动力蛋白-2膜的结合减少。有趣的是，缺乏任何已知内化信号的常驻根尖蛋白的内化也被乙醇破坏，这表明这些蛋白是通过网格蛋白介导的机制内化的。这一结论与我们的研究结果一致，即显性的负动力蛋白-2过表达会损害已知网格蛋白标志物和单跨越顶端居民的内化，但不会损害液相或筏介导的内化标志物。总之，这些结果表明，乙醇暴露通过阻止质膜的囊泡裂变，选择性地损害肝网格蛋白介导的内化。
Although alcoholic liver disease is clinically well-described, the molecular basis for alcohol-induced hepatotoxicity is not well understood. Previously, we determined that the clathrin-mediated internalization of asialoglycoprotein receptor was impaired in ethanol-treated WIF-B cells whereas the internalization of a glycophosphatidylinositol-anchored protein thought to be endocytosed via a caveolae/raft-mediated pathway was not changed suggesting that clathrin-mediated endocytosis is selectively impaired by ethanol. To test this possibility, we examined the internalization of a panel of proteins and compounds internalized by different mechanisms in control and ethanol-treated WIF-B cells. We determined that the internalization of markers known to be internalized via clathrin-mediated mechanisms was impaired. In contrast, the internalization of markers for caveolae/raft-mediated endocytosis, fluid phase internalization or non-vesicle-mediated uptake was not impaired in ethanol-treated cells. We further determined that clathrin heavy chain accumulated at the basolateral surface in small puncta in ethanol-treated cells while there was decreased dynamin-2 membrane association. Interestingly, the internalization of resident apical proteins that lack any known internalization signals was also disrupted by ethanol suggesting that these proteins are internalized via clathrin-mediated mechanisms. This conclusion is consistent with our findings that dominant negative dynamin-2 overexpression impaired internalization of known clathrin markers and single spanning apical residents, but not of markers of fluid phase or raft-mediated internalization. Together these results indicate that ethanol exposure selectively impairs hepatic clathrin-mediated internalization by preventing vesicle fission from the plasma membrane.
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WIF-B细胞：用于研究肝细胞极性的体外模型。
影响因子：
7.8
作者：
Ihrke, G;Neufeld, E B;Meads, T;Shanks, M R;Cassio, D;Laurent, M;Schroer, T A;Pagano, R E;Hubbard, A L
通讯作者：
Hubbard, A L
影响因子：
2.7
作者：
Geny, Blandine;Popoff, Michel R.
通讯作者：
Popoff, Michel R.
影响因子：
3.3
作者：
Ramnarayanan, Sai Prasad;Cheng, Christina A.;Tuma, Pamela L.
通讯作者：
Tuma, Pamela L.
影响因子：
13.5
作者：
POTTER, BJ;CHAPMAN, RWG;SHERLOCK, S
通讯作者：
SHERLOCK, S
影响因子：
2.8
作者：
TUMA, DJ;CASEY, CA;SORRELL, MF
通讯作者：
SORRELL, MF