Ekong Udeme, Zeng Shan, Dun Hao, Feirt Nikki, Guo Jiancheng, Ippagunta Nikalesh, Guarrera James V, Lu Yan, Weinberg Alan, Qu Wu, Ramasamy Ravichandran, Schmidt Ann Marie, Emond Jean C
Division of Pediatric Gastroenterology and Hepatology, Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
J Gastroenterol Hepatol. 2006 Apr;21(4):682-8. doi: 10.1111/j.1440-1746.2006.04225.x.
Severe injury to the liver, such as that induced by toxic doses of acetaminophen, triggers a cascade of events leading to hepatocyte death. It is hypothesized that activation of the receptor for advanced glycation end products (RAGE) might contribute to acetaminophen-induced liver toxicity by virtue of its ability to generate reactive oxygen species, at least in part via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and thereby activate downstream signaling pathways leading to cellular injury.
A model was employed in which toxic doses of acetaminophen (1125 mg/kg) were administered to C57BL/6 mice. To block RAGE, mice received murine soluble (s) RAGE, the extracellular ligand binding domain of the receptor that acts as a decoy to interrupt ligand-RAGE signaling.
Animals treated with sRAGE displayed increased survival compared with vehicle treatment, and markedly decreased hepatic necrosis. Consistent with an important role for RAGE-triggered oxidant stress in acetaminophen-induced injury, a significant reduction of nitrotyrosine protein adducts was observed in hepatic tissue in sRAGE-treated versus vehicle-treated mice receiving acetaminophen, in parallel with significantly increased levels of glutathione. In addition, pro-regenerative cytokines tumor necrosis factor-alpha and interleukin-6 were increased in sRAGE-treated versus vehicle-treated mice.
These findings implicate RAGE-dependent mechanisms in acetaminophen-induced liver damage and suggest that blockade of this pathway may impart beneficial effects in toxin-induced liver injury.
肝脏的严重损伤,如由毒性剂量对乙酰氨基酚引起的损伤,会引发一系列导致肝细胞死亡的事件。据推测,晚期糖基化终产物受体(RAGE)的激活可能至少部分通过烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶产生活性氧,从而激活导致细胞损伤的下游信号通路,进而导致对乙酰氨基酚诱导的肝毒性。
采用给C57BL/6小鼠注射毒性剂量对乙酰氨基酚(1125mg/kg)的模型。为阻断RAGE,小鼠接受鼠可溶性(s)RAGE,即该受体的细胞外配体结合域,其作为诱饵可中断配体-RAGE信号传导。
与载体处理相比,接受sRAGE处理的动物存活率提高,肝坏死明显减少。与RAGE触发的氧化应激在对乙酰氨基酚诱导的损伤中起重要作用一致,在接受对乙酰氨基酚的sRAGE处理小鼠的肝组织中,与载体处理小鼠相比,硝基酪氨酸蛋白加合物显著减少,同时谷胱甘肽水平显著升高。此外,与载体处理小鼠相比,接受sRAGE处理小鼠中的促再生细胞因子肿瘤坏死因子-α和白细胞介素-6增加。
这些发现表明RAGE依赖性机制参与对乙酰氨基酚诱导的肝损伤,并提示阻断该途径可能对毒素诱导的肝损伤产生有益影响。