Kuhla Angela, Thrum Michael, Schaeper Ute, Fehring Volker, Schulze-Topphoff Ulf, Abshagen Kerstin, Vollmar Brigitte
Institute for Experimental Surgery, Rostock University Medical Center, University of Rostock, Schillingallee 69a, 18057, Rostock, Germany,
Apoptosis. 2015 Apr;20(4):500-11. doi: 10.1007/s10495-015-1088-2.
Acute liver failure (ALF) is a life threatening disease for which only few treatment options exist. The molecular pathways of disease progression are not well defined, but the death receptor Fas (CD95/Apo-1) appears to play a pivotal role in hepatocyte cell death and the development of ALF. Here, we explored posttranscriptional gene silencing of Fas by RNAi to inhibit pathophysiological gene expression. For targeting Fas expression in mice, Fas siRNA was formulated with the liver-specific siRNA delivery system DBTC. Treatment of mice with DBTC/siRNA(Fas) reduced Fas expression in the liver, but not in the spleen, lung, kidney or heart. Furthermore, silencing of Fas receptor was effective in blocking or reducing several aspects of ALF when it was tested in mice exposed to galactosamine/lipopolysaccharide (G/L), a well-known model of ALF. The application of DBTC/siRNA(Fas) 48 h prior G/L exposure resulted in amelioration of hepatic perfusion, reduction of hepatocellular death and increase of survival rate. The administration of DBTC/siRNA(Fas) formulation further diminished the inflammatory response upon G/L challenge, as indicated by a marked decrease of TNFα mRNA expression. However, IL-6 plasma concentration remained unaffectedly by DBTC/siRNA(Fas) formulation. Since the specific silencing of hepatic Fas expression only partially protected from inflammation, but completely attenuated apoptotic and necrotic cell death as well as microcirculatory dysfunction, the development of therapeutic strategies with DBTC lipoplex formulations to treat ALF should be combined with anti-inflammatory strategies to reach maximal therapeutic efficacy.
急性肝衰竭（ALF）是一种危及生命的疾病，目前仅有少数治疗选择。疾病进展的分子途径尚不明确，但死亡受体Fas（CD95/Apo-1）似乎在肝细胞死亡和ALF的发展中起关键作用。在此，我们探索了通过RNA干扰进行Fas的转录后基因沉默，以抑制病理生理基因表达。为了在小鼠中靶向Fas表达，将Fas小干扰RNA（siRNA）与肝脏特异性siRNA递送系统DBTC配制在一起。用DBTC/siRNA（Fas）治疗小鼠可降低肝脏中的Fas表达，但在脾脏、肺、肾或心脏中则不会。此外，在暴露于半乳糖胺/脂多糖（G/L）（一种众所周知的ALF模型）的小鼠中进行测试时，Fas受体的沉默在阻断或减少ALF的几个方面是有效的。在G/L暴露前48小时应用DBTC/siRNA（Fas）可改善肝脏灌注，减少肝细胞死亡并提高存活率。DBTC/siRNA（Fas）制剂的给药进一步减轻了G/L攻击后的炎症反应，这表现为TNFα mRNA表达明显降低。然而，DBTC/siRNA（Fas）制剂对IL-6血浆浓度没有影响。由于肝脏Fas表达的特异性沉默仅部分保护免受炎症，但完全减轻了凋亡和坏死性细胞死亡以及微循环功能障碍，因此用DBTC脂质体复合物制剂治疗ALF的治疗策略的开发应与抗炎策略相结合，以达到最大治疗效果。
