Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States of America; Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States of America.
Department of Pharmacology, Toxicology, & Therapeutics, University of Kansas Medical Center, Kansas City, KS, United States of America.
Toxicol Appl Pharmacol. 2020 Jun 1;396:114982. doi: 10.1016/j.taap.2020.114982. Epub 2020 Mar 30.
Oxidative stress contributes to acetaminophen (APAP) hepatotoxicity. Since lipid peroxidation produces reactive aldehydes, we investigated whether activation of mitochondrial aldehyde dehydrogenase-2 (ALDH2) with Alda-1 decreases liver injury after APAP. Male C57BL/6 mice fasted overnight received Alda-1 (20 mg/kg, i.p.) or vehicle 30 min before APAP (300 mg/kg, i.p.). Blood and livers were collected 2 or 24 h after APAP. Intravital multiphoton microscopy of rhodamine 123 (Rh123) and propidium iodide (PI) fluorescence was conducted 6 h after APAP administration to detect mitochondrial polarization status and cell death. 4-Hydroxynonenal protein adducts were present in 0.1% of tissue area without APAP treatment but increased to 7% 2 h after APAP treatment, which Alda-1 blunted to 1%. Serum alanine and aspartate aminotransferases increased to 7594 and 9768 U/L at 24 h respectively, which decreased ≥72% by Alda-1. Alda-1 also decreased centrilobular necrosis at 24 h after APAP from 47% of lobular areas to 21%. N-acetyl-p-benzoquinone imine protein adduct formation and c-Jun-N-terminal kinase phosphorylation increased after APAP as expected, but Alda-1 did not alter these changes. Without APAP, no mitochondrial depolarization was detected by intravital microscopy. At 6 h after APAP, 62% of tissue area showed depolarization, which decreased to 33.5% with Alda-1. Cell death as detected by PI labeling increased from 0 to 6.8 cells per 30× field 6 h after APAP, which decreased to 0.6 cells by Alda-1. In conclusion, aldehydes are important mediators of APAP hepatotoxicity. Accelerated aldehyde degradation by ALDH2 activation with Alda-1 decreases APAP hepatotoxicity by protection against mitochondrial dysfunction.
氧化应激导致对乙酰氨基酚（APAP）肝毒性。由于脂质过氧化产生反应性醛，我们研究了用 Alda-1 激活线粒体醛脱氢酶-2（ALDH2）是否会减少 APAP 后的肝损伤。雄性 C57BL/6 小鼠禁食过夜，在给予 APAP（300mg/kg，ip）前 30 分钟给予 Alda-1（20mg/kg，ip）或载体。在给予 APAP 后 2 或 24 小时收集血液和肝脏。给予 APAP 后 6 小时进行罗丹明 123（Rh123）和碘化丙啶（PI）荧光的活体多光子显微镜检查，以检测线粒体极化状态和细胞死亡。在没有 APAP 处理的情况下，组织面积的 0.1%存在 4-羟基壬烯醛蛋白加合物，但在 APAP 处理后 2 小时增加到 7%，Alda-1 将其减少到 1%。血清丙氨酸和天冬氨酸氨基转移酶在 24 小时时分别增加到 7594 和 9768 U/L，Alda-1 将其降低≥72%。Alda-1 还将 APAP 后 24 小时的中央小叶坏死从肝小叶区域的 47%减少到 21%。如预期的那样，APAP 后 N-乙酰苯醌亚胺蛋白加合物形成和 c-Jun-N 末端激酶磷酸化增加，但 Alda-1 没有改变这些变化。在没有 APAP 的情况下，活体显微镜检查未检测到线粒体去极化。在给予 APAP 后 6 小时，组织面积的 62%显示去极化，用 Alda-1 降低至 33.5%。用 PI 标记检测到的细胞死亡从 0 增加到 6.8 个细胞/30×视野，用 Alda-1 降低到 0.6 个细胞。总之，醛是 APAP 肝毒性的重要介质。用 Alda-1 激活 ALDH2 加速醛的降解，通过防止线粒体功能障碍来减少 APAP 肝毒性。
