Nieto Natalia, Rojkind Marcos
Mount Sinai School of Medicine, Department of Medicine, Division of Liver Diseases, New York, NY, USA.
J Hepatol. 2007 Feb;46(2):330-9. doi: 10.1016/j.jhep.2006.09.010. Epub 2006 Nov 2.
BACKGROUND/AIMS: Alcoholic liver disease is associated with nutritional deficiency and it may aggravate within the context of fatty liver. We investigated the relationship between alcohol intake (whiskey binge drinking) and a choline-deficient diet (CD) and assessed whether stellate cells could contribute to liver injury in this model.
Rats fed the CD diet plus whiskey showed increased liver damage compared to rats fed the CD diet, as demonstrated by H&E staining, elevated transaminases, steatosis, TNF-alpha levels, enhanced CYP2E1 activity, impaired antioxidant defense, elevated lipid peroxidation, and protein carbonyls. The combined treatment triggered an apoptotic response as determined by elevated Bax, caspase-3 activity, cytochrome-c release, and decreased Bcl-2 and Bcl-XL. Stellate cells were activated as increased expression of alpha-Sma was observed over that by the CD diet alone. The combined treatment shifted extracellular matrix remodeling towards a pro-fibrogenic response due to up-regulation of collagen I, TIMP1, and Hsp47 proteins, along with down-regulation of MMP13, MMP2, and MMP9 expression, proteases which degrade collagen I. These events were accompanied by increased phosphorylation of p38, a kinase that elevates collagen I.
Repeated alcohol binges in the context of mild steatosis may promote activation of stellate cells and contribute to liver injury.
背景/目的:酒精性肝病与营养缺乏有关,且在脂肪肝背景下可能会加重。我们研究了酒精摄入量(威士忌暴饮)与胆碱缺乏饮食(CD)之间的关系,并评估了在该模型中星状细胞是否会导致肝损伤。
与仅喂食CD饮食的大鼠相比,喂食CD饮食加威士忌的大鼠肝损伤增加,这通过苏木精-伊红染色、转氨酶升高、脂肪变性、肿瘤坏死因子-α水平、CYP2E1活性增强、抗氧化防御受损、脂质过氧化升高和蛋白质羰基化得以证明。联合治疗引发了凋亡反应,这通过Bax升高、半胱天冬酶-3活性、细胞色素-c释放以及Bcl-2和Bcl-XL降低来确定。星状细胞被激活,因为观察到α-Sma的表达比仅喂食CD饮食时增加。联合治疗使细胞外基质重塑转向促纤维化反应方向,这是由于I型胶原、金属蛋白酶组织抑制因子1(TIMP1)和热休克蛋白47(Hsp47)蛋白上调,以及降解I型胶原的蛋白酶基质金属蛋白酶13(MMP13)、基质金属蛋白酶2(MMP2)和基质金属蛋白酶9(MMP9)表达下调所致。这些事件伴随着p38磷酸化增加,p38是一种可升高I型胶原的激酶。
在轻度脂肪变性的情况下反复暴饮酒精可能会促进星状细胞激活并导致肝损伤。