Experimental Hepatic Ischemia-Reperfusion Unit, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas, IDIBAPS-Ciberehd, Barcelona, Spain.
J Pineal Res. 2013 Aug;55(1):65-78. doi: 10.1111/jpi.12051. Epub 2013 Mar 29.
Ischemia/reperfusion injury (IRI) associated with liver transplantation plays an important role in the induction of graft injury. Prolonged cold storage remains a risk factor for liver graft outcome, especially when steatosis is present. Steatotic livers exhibit exacerbated endoplasmic reticulum (ER) stress that occurs in response to cold IRI. In addition, a defective liver autophagy correlates well with liver damage. Here, we evaluated the combined effect of melatonin and trimetazidine as additives to IGL-1 solution in the modulation of ER stress and autophagy in steatotic liver grafts through activation of AMPK. Steatotic livers were preserved for 24 hr (4°C) in UW or IGL-1 solutions with or without MEL + TMZ and subjected to 2-hr reperfusion (37°C). We assessed hepatic injury (ALT and AST) and function (bile production). We evaluated ER stress (GRP78, PERK, and CHOP) and autophagy (beclin-1, ATG7, LC3B, and P62). Steatotic livers preserved in IGL-1 + MEL + TMZ showed lower injury and better function as compared to those preserved in IGL-1 alone. IGL-1 + MEL + TMZ induced a significant decrease in GRP78, pPERK, and CHOP activation after reperfusion. This was consistent with a major activation of autophagic parameters (beclin-1, ATG7, and LC3B) and AMPK phosphorylation. The inhibition of AMPK induced an increase in ER stress and a significant reduction in autophagy. These data confirm the close relationship between AMPK activation and ER stress and autophagy after cold IRI. The addition of melatonin and TMZ to IGL-1 solution improved steatotic liver graft preservation through AMPK activation, which reduces ER stress and increases autophagy.
缺血/再灌注损伤（IRI）与肝移植相关，在诱导移植物损伤中起重要作用。长时间的冷保存仍然是肝移植物预后的一个危险因素，尤其是在存在脂肪变性的情况下。脂肪变性的肝脏表现出加剧的内质网（ER）应激，这是对冷 IRI 的反应。此外，肝脏自噬功能缺陷与肝损伤密切相关。在这里，我们评估了褪黑素和曲美他嗪作为添加剂加入 IGL-1 溶液中，通过激活 AMPK 来调节脂肪变性肝移植物中的 ER 应激和自噬。将脂肪变性的肝脏在 UW 或 IGL-1 溶液中保存 24 小时（4°C），有或没有 MEL+TMZ，并进行 2 小时再灌注（37°C）。我们评估了肝损伤（ALT 和 AST）和功能（胆汁生成）。我们评估了 ER 应激（GRP78、PERK 和 CHOP）和自噬（beclin-1、ATG7、LC3B 和 P62）。与单独使用 IGL-1 相比，在 IGL-1+MEL+TMZ 中保存的脂肪变性肝脏显示出较低的损伤和更好的功能。IGL-1+MEL+TMZ 在再灌注后显著降低了 GRP78、pPERK 和 CHOP 的激活。这与自噬参数（beclin-1、ATG7 和 LC3B）和 AMPK 磷酸化的主要激活一致。AMPK 的抑制诱导 ER 应激的增加和自噬的显著减少。这些数据证实了冷 IRI 后 AMPK 激活与 ER 应激和自噬之间的密切关系。褪黑素和曲美他嗪的加入通过激活 AMPK 改善了 IGL-1 溶液中脂肪变性肝移植物的保存，从而减少 ER 应激并增加自噬。
