Alcohol-induced alterations in hepatic microtubule dynamics can be explained by impaired histone deacetylase 6 function.
Alcohol-induced alterations in hepatic microtubule dynamics can be explained by impaired histone deacetylase 6 function.
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DOI：
10.1002/hep.22481
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发表时间：
2008-11
期刊：
影响因子：
13.5
通讯作者：
Tuma, Pamela L.
中科院分区：
文献类型：
--
作者：
Shepard, Blythe D.;Joseph, Rohan A.;Kannarkat, George T.;Rutledge, Tara M.;Tuma, Dean J.;Tuma, Pamela L.
我们一直在使用极化的肝wi - b细胞来检测乙醇诱导的肝损伤。这些细胞在培养中分化并维持许多肝脏特异性活动，包括代谢酒精的能力。先前，我们发现微管在乙醇处理的wi - b细胞中乙酰化程度更高，更稳定，并且微管乙酰化的增加需要乙醇代谢，并且可能由乙醛介导。本研究旨在确定微管乙酰化增加的机制。我们检测了两种已知的微管去乙酰化酶，组蛋白去乙酰化酶6 （HDAC6）和Sirtuin T2 （SirT2）在wi - b细胞中的表达。免疫印迹、免疫荧光显微镜和使用SirT2抑制剂烟酰胺的检测显示，wi - b细胞不表达SirT2。相反，HDAC6在wi - b细胞中高表达。添加HDAC6抑制剂trichostatin A （TSA）诱导的微管乙酰化程度与乙醇处理的细胞相同（约为三倍）。虽然免疫荧光标记显示HDAC6在乙醇处理细胞中的分布没有改变，但免疫印迹显示HDAC6蛋白水平略有下降。在诺可达唑处理的细胞中，HDAC6的溶解度增加，表明微管结合受损。直接微管结合试验证实了这一假设。4-甲基吡唑部分阻止了微管结合的减少，表明乙醛部分介导了这种作用。有趣的是，来自乙醇处理细胞的HDAC6能够结合外源性微管蛋白并使其去乙酰化，其程度与对照组相同，这表明乙醇诱导的微管蛋白修饰阻止了HDAC6与内源性微管的结合。我们提出，在乙醇处理的细胞中，较低的HDAC6水平加上微管结合减少导致微管蛋白乙酰化增加。
We have been using polarized, hepatic WIF-B cells to examine ethanol-induced liver injury. These cells polarize in culture and maintain numerous liver-specific activities including the ability to metabolize alcohol. Previously, we found that microtubules were more highly acetylated and more stable in ethanol-treated WIF-B cells and that increased microtubule acetylation required ethanol metabolism and was likely mediated by acetaldehyde. This study was aimed at identifying the mechanism responsible for increased microtubule acetylation. We examined the expression of two known microtubule deacetylases, histone deacetylase 6 (HDAC6) and Sirtuin T2 (SirT2), in WIF-B cells. Immunoblotting, immunofluorescence microscopy, and assays using the SirT2 inhibitor nicotinamide revealed that WIF-B cells do not express SirT2. In contrast, HDAC6 was highly expressed in WIF-B cells. Addition of trichostatin A (TSA), an HDAC6 inhibitor, induced microtubule acetylation to the same extent as in ethanol-treated cells (approximately threefold). Although immunofluorescence labeling revealed that HDAC6 distribution did not change in ethanol-treated cells, immunoblotting showed HDAC6 protein levels slightly decreased. HDAC6 solubility was increased in nocodazole-treated cells, suggesting impaired microtubule binding. Direct microtubule binding assays confirmed this hypothesis. The decreased microtubule binding was partially prevented by 4-methyl pyrazole, indicating the effect was in part mediated by acetaldehyde. Interestingly, HDAC6 from ethanol-treated cells was able to bind and deacetylate exogenous tubulin to the same extent as control, suggesting that ethanol-induced tubulin modifications prevented HDAC6 binding to endogenous microtubules. We propose that lower HDAC6 levels combined with decreased microtubule binding lead to increased tubulin acetylation in ethanol-treated cells.
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影响因子：
64.8
作者：
Hubbert, C;Guardiola, A;Yao, TP
通讯作者：
Yao, TP
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：
5.3
作者：
Li, Wenbo;Zhang, Bin;Liang, Fengyi
通讯作者：
Liang, Fengyi
影响因子：
64.8
作者：
LAEMMLI, UK
通讯作者：
LAEMMLI, UK
DOI：
10.1073/pnas.96.9.4868
发表时间：
1999-04-27
影响因子：
11.1
作者：
Grozinger, CM;Hassig, CA;Schreiber, SL
通讯作者：
Schreiber, SL