Acetaminophen (APAP)-induced acute liver failure (ALF) is a life-threatening disease with only a few treatment options available. Though extensive research has been conducted for more than 40 years, the underlying pathomechanisms are not completely understood. Here, we studied as to whether APAP-induced ALF can be prevented in mice by silencing the BH3-interacting domain death agonist (Bid) as a potential key player in APAP pathology. For silencing Bid expression in mice, siRNABid was formulated with the liver-specific siRNA delivery system DBTC and administered 48 h prior to APAP exposure. Mice which were pre-treated with HEPES (vehicleHEPES) and siRNALuci served as siRNA controls. Hepatic pathology was assessed by in vivo fluorescence microscopy, molecular biology, histology and laboratory analysis 6 h after APAP or PBS exposure. Application of siRNABid caused a significant decrease of mRNA and protein expression of Bid in APAP-exposed mice. Off-targets, such as cytochrome P450 2E1 and glutathione, which are known to be consumed under APAP intoxication, were comparably reduced in all APAP-exposed mice, underlining the specificity of Bid silencing. In APAP-exposed mice non-sterile inflammation with leukocyte infiltration and perfusion failure remained almost unaffected by Bid silencing. However, the Bid silencing reduced hepatocellular damage, evident by a remarkable decrease of DNA fragmented cells in APAP-exposed mice. In these mice, the expression of the pro-apoptotic protein Bax, which recently gained importance in the cell death pathway of regulated necrosis, was also significantly reduced, in line with a decrease in both, necrotic liver tissue and plasma transaminase activities. In addition, plasma levels of HMGB1, a marker of sterile inflammation, were significantly diminished. In conclusion, the liver-specific silencing of Bid expression did not protect APAP-exposed mice from microcirculatory dysfunction, but markedly protected the liver from necrotic cell death and in consequence from sterile inflammation. The study contributes to the understanding of the molecular mechanism of the APAP-induced pathogenic pathway by strengthening the importance of Bid and Bid silencing associated effects.

中文翻译：

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肝脏特异性出价沉默可抑制APAP诱导的小鼠细胞死亡。

对乙酰氨基酚（APAP）诱发的急性肝衰竭（ALF）是威胁生命的疾病，只有几种治疗方法可供选择。尽管已进行了40多年的广泛研究，但尚未完全理解潜在的发病机理。在这里，我们研究了是否可以通过沉默BH3相互作用域死亡激动剂（Bid）作为APAP病理学中的潜在关键角色来预防APAP诱导的ALF。为了使小鼠中的Bid表达沉默，将siRNABid与肝脏特异性siRNA递送系统DBTC一起配制，并在暴露APAP前48小时给药。用HEPES（vehicleHEPES）和siRNALuci预处理的小鼠用作siRNA对照。APAP或PBS暴露6小时后，通过体内荧光显微镜，分子生物学，组织学和实验室分析评估肝脏病理。siRNABid的应用导致暴露于APAP的小鼠中Bid的mRNA和蛋白表达显着降低。在所有暴露于APAP的小鼠中，靶标降低的靶点，例如细胞色素P450 2E1和谷胱甘肽，都已知在APAP毒性下被消耗，从而降低了竞标的特异性。在暴露于APAP的小鼠中，具有白细胞浸润和灌注失败的非无菌炎症几乎不受出价沉默的影响。但是，Bid沉默降低了肝细胞损伤，这在暴露于APAP的小鼠中DNA碎片细胞显着减少的情况下很明显。在这些小鼠中，促凋亡蛋白Bax的表达也显着降低，最近在调节性坏死的细胞死亡途径中它的表达与此相一致，坏死的肝组织和血浆转氨酶活性。此外，血浆HMGB1（无菌炎症标志物）的水平也显着降低。总之，Bid表达的肝脏特异性沉默不能保护暴露于APAP的小鼠免受微循环功能障碍的影响，但可以明显保护肝脏免受坏死细胞死亡以及无菌炎症的后果。这项研究通过增强出价和出价沉默相关效应的重要性，有助于理解APAP致病途径的分子机制。但显着保护肝脏免受坏死细胞死亡以及无菌炎症的后果。这项研究通过增强出价和出价沉默相关效应的重要性，有助于理解APAP致病途径的分子机制。但显着保护肝脏免受坏死细胞死亡以及无菌炎症的后果。这项研究通过增强出价和出价沉默相关效应的重要性，有助于理解APAP致病途径的分子机制。