Department of Medicine, University of Massachusetts Medical School, Worcester, 01605, USA.
Alcohol Clin Exp Res. 2012 Aug;36(8):1397-406. doi: 10.1111/j.1530-0277.2012.01739.x. Epub 2012 Feb 29.
Reactive oxygen species contribute to steatosis and inflammation in alcoholic liver disease (ALD). Here, we evaluated the selective contribution of p47phox, a critical subunit of nicotinamide adenine dinucleotide phosphate oxidase (NADPH) oxidase complex, in liver parenchymal cells and in bone marrow (BM)-derived cells.
Female C57Bl/6 wild type [WT], total body p47phox-deficient knockout [KO] or p47phox chimera mice generated by BM transplantation of p47phox-KO-BM into irradiated WT mice (WT/p47phox-KO-BM mice) received 5% Lieber-DeCarli alcohol or control (pair feeding) diet for 4 weeks.
Alcohol-induced liver steatosis as measured by Oil Red O staining and serum triglyceride up-regulation were prevented in p47phox-KO mice but not in WT/p47phox-KO-BM chimeras compared to WT controls. Serum alanine aminotransferase (ALT) was significantly increased in alcohol-fed WT mice but not in p47phox-KO mice compared to pair-fed controls. There was no protection from alcohol-induced increase in ALT and liver damage in the WT/p47phox-KO-BM mice. Alcohol-induced liver steatosis was accompanied by up-regulation of the lipid droplet-stabilizing protein, adipocyte differentiation-related protein (ADRP), and the fatty acid synthesis-associated genes, fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACACA). Total body deficiency in p47phox but not selective absence of p47phox in BM-derived cells prevented alcohol-induced up-regulation of ADRP, FASN, and ACACA in the liver. Finally, alcohol-induced activation and DNA binding of nuclear factor κB (NF-κB), a master regulator of inflammation, were significantly increased after alcohol feeding in WT but not in p47phox-KO mice. Selective deficiency of p47phox in BM-derived cells (WT/p47phox-KO-BM chimera) failed to prevent NF-κB induction after alcohol feeding.
Total body deficiency in p47phox subunit of NADPH oxidase complex protects mice from alcohol-induced liver steatosis via mechanisms involving ADRP, FASN, and ACACA as well as from alcohol-induced NF-κB activation. In contrast, selective absence of p47phox in BM-derived cells fails to provide protection via these mechanisms. These results suggest that p47phox in parenchymal cells plays a critical role in the pathogenesis of ALD.
活性氧在酒精性肝病（ALD）中的脂肪变性和炎症中起作用。在这里，我们评估了烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NADPH）氧化酶复合物的关键亚基 p47phox 在肝实质细胞和骨髓（BM）衍生细胞中的选择性贡献。
雌性 C57Bl/6 野生型 [WT]、全身 p47phox 缺陷型敲除 [KO]或通过将 p47phox-KO-BM 骨髓移植到照射 WT 小鼠中产生的 p47phox 嵌合体小鼠 [WT/p47phox-KO-BM 小鼠] 接受 5% Lieber-DeCarli 酒精或对照（配对喂养）饮食 4 周。
与 WT 对照相比，p47phox-KO 小鼠可预防酒精诱导的肝脂肪变性，如油红 O 染色和血清甘油三酯上调，但 WT/p47phox-KO-BM 嵌合体小鼠则不能。与配对喂养对照相比，酒精喂养的 WT 小鼠的血清丙氨酸氨基转移酶（ALT）显着升高，但 p47phox-KO 小鼠则没有。WT/p47phox-KO-BM 小鼠未受到酒精诱导的 ALT 和肝损伤增加的保护。酒精诱导的肝脂肪变性伴随着脂质滴稳定蛋白、脂肪细胞分化相关蛋白（ADRP）和脂肪酸合成相关基因脂肪酸合酶（FASN）和乙酰辅酶 A 羧化酶（ACACA）的上调。全身缺乏 p47phox 但不是 BM 衍生细胞中 p47phox 的选择性缺失可防止酒精诱导的 ADRP、FASN 和 ACACA 在肝脏中的上调。最后，酒精喂养后，WT 小鼠中核因子 κB（NF-κB）的激活和 DNA 结合，一种炎症的主要调节剂，显着增加，但 p47phox-KO 小鼠则没有。酒精喂养后，BM 衍生细胞（WT/p47phox-KO-BM 嵌合体）中 p47phox 的选择性缺失未能阻止 NF-κB 的诱导。
NADPH 氧化酶复合物 p47phox 亚基的全身缺乏通过涉及 ADRP、FASN 和 ACACA 以及酒精诱导的 NF-κB 激活的机制保护小鼠免受酒精诱导的肝脂肪变性。相比之下，BM 衍生细胞中 p47phox 的选择性缺失未能通过这些机制提供保护。这些结果表明，实质细胞中的 p47phox 在 ALD 的发病机制中起关键作用。
