Acute and Chronic Ethanol Administration Differentially Modulate Hepatic Autophagy and Transcription Factor EB
Acute and Chronic Ethanol Administration Differentially Modulate Hepatic Autophagy and Transcription Factor EB
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DOI：
10.1111/acer.12904
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发表时间：
2015-12-01
影响因子：
3.2
通讯作者：
Donohue, Terrence M., Jr.
中科院分区：
文献类型：
--
作者：
Thomes, Paul G.;Trambly, Casey S.;Donohue, Terrence M., Jr.
背景资料：慢性乙醇（EtOH）消耗减慢了长寿命蛋白质的分解，表明其减缓了肝巨自噬（以下称为自噬），这是大多数真核细胞中的关键溶酶体分解代谢途径。自噬和溶酶体生物发生是相关的。两者都受转录因子EB（TFEB）的调控。在这里，我们测试了TFEB是否可以用作自噬活性的单一指标，通过量化其在急性和慢性EtOH给药的小鼠肝脏中的核含量。我们将核TFEB与自噬的特定指数相关联。方法：在急性实验中，我们用单剂量的乙醇或磷酸盐缓冲盐水（PBS）灌胃GFP-LC 3（tg）小鼠。我们喂小鼠慢性喂养他们的控制或EtOH液体diets.Results：与PBS-gavaged控制相比，EtOH-gavaged小鼠的肝脏表现出更大的自噬体（AV）的数量，较高的发病率AV-溶酶体共定位，和游离GFP的水平升高，所有这些都表明增强的自噬，这与较高的TFEB核含量。与配对喂养的对照组相比，EtOH喂养的小鼠的肝脏表现出较高的AV数量，但具有较低的溶酶体数量，较低的AV-溶酶体共定位，较高的P62/SQSTM 1水平和较低的游离GFP水平。后者的发现与EtOH喂养的小鼠中较低的核TFEB水平相关。因此，急性EtOH灌胃后增强的自噬与较高的核TFEB含量相关。相反，慢性乙醇喂养抑制肝自噬，与较低的核TFEB content.Conclusions：我们的研究结果表明，急性乙醇灌胃对肝自噬的影响显着不同，从慢性乙醇喂养后。每种方案都明显影响TFEB定位，进而调节肝自噬和溶酶体生物合成。
Background: Chronic ethanol (EtOH) consumption decelerates the catabolism of long-lived proteins, indicating that it slows hepatic macroautophagy (hereafter called autophagy) a crucial lysosomal catabolic pathway in most eukaryotic cells. Autophagy and lysosome biogenesis are linked. Both are regulated by the transcription factor EB (TFEB). Here, we tested whether TFEB can be used as a singular indicator of autophagic activity, by quantifying its nuclear content in livers of mice subjected to acute and chronic EtOH administration. We correlated nuclear TFEB to specific indices of autophagy.Methods: In acute experiments, we gavaged GFP-LC3(tg) mice with a single dose of EtOH or with phosphate buffered saline (PBS). We fed mice chronically by feeding them control or EtOH liquid diets.Results: Compared with PBS-gavaged controls, livers of EtOH-gavaged mice exhibited greater autophagosome (AV) numbers, a higher incidence of AV-lysosome co-localization, and elevated levels of free GFP, all indicating enhanced autophagy, which correlated with a higher nuclear content of TFEB. Compared with pair-fed controls, livers of EtOH-fed mice exhibited higher AV numbers, but had lower lysosome numbers, lower AV-lysosome co-localization, higher P62/SQSTM1 levels, and lower free GFP levels. The latter findings correlated with lower nuclear TFEB levels in EtOH-fed mice. Thus, enhanced autophagy after acute EtOH gavage correlated with a higher nuclear TFEB content. Conversely, chronic EtOH feeding inhibited hepatic autophagy, associated with a lower nuclear TFEB content.Conclusions: Our findings suggest that the effect of acute EtOH gavage on hepatic autophagy differs significantly from that after chronic EtOH feeding. Each regimen distinctly affects TFEB localization, which in turn, regulates hepatic autophagy and lysosome biogenesis.