Adipose differentiation-related protein is a reliable lipid droplet marker in alcoholic fatty liver of rats
Adipose differentiation-related protein is a reliable lipid droplet marker in alcoholic fatty liver of rats
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DOI：
10.1111/j.1530-0277.2008.00624.x
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发表时间：
2008-04-01
影响因子：
3.2
通讯作者：
Lieber, Charles S.
中科院分区：
文献类型：
--
作者：
Mak, Ki M.;Ren, Chaoling;Lieber, Charles S.
背景：脂肪分化相关蛋白（ADRP）是一种包裹细胞质脂滴的脂滴相关蛋白。本研究评估了饮酒是否会增强 ADRP 的表达以及 ADRP 是否是大鼠酒精性脂肪肝中的脂滴标志物。由于中链甘油三酯 (MCT) 可以减少酒精性肝脂肪变性，因此还评估了它们对 ADRP 的影响。 方法：通过食用 Lieber-DeCarli 酒精液体饮食，并用或不用 MCT（热量的 32%）替代长链甘油三酯 (LCT)，诱导大鼠脂肪肝。在福尔马林固定、石蜡包埋的肝切片中进行 ADRP 的免疫组织化学染色。 ADRP 免疫染色通过图像分析进行量化。通过化学方法测量三酰基甘油。分别通过实时聚合酶链反应和蛋白质印迹分析 ADRP mRNA 和蛋白质。采用双重染色技术区分肝细胞中的 ADRP 和糖原。结果：21 天的酒精喂养增加了肝小叶中心小叶和中部带状区域的 ADRP 染色，与肝脏中的脂肪沉积一致。用 MCT 替代酒精饮食中的 LCT 可减少 ADRP 免疫染色，同时减少脂肪变性。 MCT 还减弱了酒精后 ADRP mRNA 和蛋白质的上调。在脂肪变性肝细胞中，ADRP 选择性地对大泡和微泡脂滴的表面进行染色。 ADRP 免疫染色与肝三酰甘油水平定量相关，验证 ADRP 作为可靠的脂滴标记物。与苏木精和伊红染色相比，ADRP 对微泡脂滴的检测更为敏感。 ADRP 免疫染色还可以区分脂滴和糖原，如 ADRP 和糖原双染色所示。结论：酒精诱导脂肪肝增强 ADRP 表达，MCT 对抗酒精作用。 ADRP 是酒精性脂肪肝中脂滴的可靠且敏感的标记物。 ADRP 免疫染色可以量化肝细胞中的脂肪变化，并可用作评估饮食或药物对抗肝脂肪变性的功效的辅助技术。
Background: Adipose differentiation-related protein (ADRP) is a lipid droplet-associated protein that coats cytoplasmic lipid droplets. The present study evaluated whether alcohol feeding enhances ADRP expression and whether ADRP is a lipid droplet marker in alcoholic fatty liver of rats. Because medium-chain triglycerides (MCT) reduce alcoholic hepatosteatosis, their effects on ADRP were also evaluated.Methods: Fatty liver was induced in rats by the consumption of the Lieber-DeCarli alcohol liquid diet with or without replacement of long-chain triglycerides (LCT) by MCT (32% of calories). Immunohistochemical staining for ADRP was performed in formalin-fixed, paraffin-embedded liver sections. ADRP immunostaining was quantified by image analysis. Triacylglycerol was measured chemically. ADRP mRNA and protein were analyzed by real-time polymerase chain reaction and western blot, respectively. Double staining technique was performed to distinguish ADRP from glycogen in hepatocytes.Results: Alcohol feeding for 21 days increased ADRP staining in the centrilobular and mid zonal regions of the liver lobules coincident with fat deposition in the liver. Replacing LCT in the alcohol diet with MCT diminished ADRP immunostaining in parallel with reduced steatosis. MCT also attenuated the up-regulation of ADRP mRNA and protein after alcohol. In steatotic hepatocytes ADRP selectively stained the surface of macrovesicular and microvesicular lipid droplets. ADRP immunostaining quantitatively correlated with hepatic triacylglycerol levels, validating ADRP as a reliable lipid droplet marker. Compared with hematoxylin and eosin stains, ADRP was more sensitive in detecting microvesicular lipid droplets. ADRP immunostaining also distinguished lipid droplets from glycogen, as demonstrated by double staining for ADRP and glycogen.Conclusions: Alcohol induction of fatty liver enhances ADRP expression and MCT oppose the alcohol effects. ADRP is a reliable and sensitive marker for lipid droplets in alcoholic fatty liver. ADRP immunostaining permits quantification of fatty change in hepatocytes and can be used as an ancillary technique in assessing the efficacy of diets or drugs against hepatosteatosis.