Inhibition of autophagy promotes CYP2E1-dependent toxicity in HepG2 cells via elevated oxidative stress, mitochondria dysfunction and activation of p38 and JNK MAPK.
Inhibition of autophagy promotes CYP2E1-dependent toxicity in HepG2 cells via elevated oxidative stress, mitochondria dysfunction and activation of p38 and JNK MAPK.
复制标题
自噬的抑制通过升高氧化应激、线粒体功能障碍以及 p38 和 JNK MAPK 的激活，促进 HepG2 细胞中 CYP2E1 依赖性毒性。
DOI：
10.1016/j.redox.2013.10.008
复制
发表时间：
2013
期刊：
影响因子：
11.4
通讯作者：
Cederbaum, Arthur I.
中科院分区：
文献类型：
--
作者：
Wu, Defeng;Cederbaum, Arthur I.
自噬已被证明对药物和酒精诱导的肝损伤具有保护作用。CYP 2 E1在乙醇、致癌物和某些药物的毒性中起作用。抑制自噬增加了野生型和CYP 2 E1敲入小鼠的乙醇毒性和脂肪蓄积，但在CYP 2 E1敲除小鼠以及表达CYP 2 E1的HepG 2细胞（E47细胞）中没有增加，但在缺乏CYP 2 E1的HepG 2细胞（C34细胞）中没有增加。本研究的目的是评估自噬的调节是否会影响E47细胞中CYP 2 E1依赖的细胞毒性。用于促进CYP 2 E1依赖性毒性的药物是多不饱和脂肪酸、花生四烯酸（AA）、丁硫基磺酰亚胺（BSO）（消耗GSH）和CCl 4（代谢为CCl 3自由基）。这三种试剂使E47细胞活力降低，这在3-甲基腺嘌呤（3-MA）或Atg 7 siRNA抑制自噬后增强。雷帕霉素增加了自噬，降低了毒性，并且对不表达CYP 2 E1的C34细胞毒性低得多。毒性主要是坏死，并与活性氧产生和氧化应激的增加; 3-MA增加，而雷帕霉素钝化氧化应激。抗氧化剂N-乙酰半胱氨酸可以阻止自噬被抑制时产生的增强的毒性和ROS形成。AA、BSO和CCl 4引起线粒体功能障碍，降低细胞ATP水平，升高线粒体ROS产生。这种线粒体功能障碍通过用3-MA抑制自噬而增强，但当雷帕霉素增加自噬时降低。AA可激活丝裂原活化蛋白激酶p38 MAPK和JNK，尤其是在自噬被抑制时，p38 MAPK和JNK的化学抑制剂可降低3-MA引起的AA毒性。这些结果表明，自噬对已知由CYP 2 E1激活的几种药物产生的毒性具有保护作用。由于CYP 2 E1在乙醇、药物和致癌物的毒性中起重要作用，并且在各种病理生理条件下被激活，如糖尿病、NASH和肥胖症，因此尝试刺激自噬可能有益于预防/降低CYP 2 E1/乙醇肝损伤。在表达CYP 2 E1的HepG 2 E47细胞中抑制自噬促进AA、BSO和CCl 4毒性。E47细胞自噬减少增加了活性氧的产生和氧化应激，并增强了线粒体功能障碍。自噬抑制增强AA对p38 MAPK和JNK的激活，这种激活有助于AA的毒性。自噬对已知由CYP 2 E1激活的药物产生的毒性具有保护作用。
Autophagy has been shown to be protective against drug and alcohol-induced liver injury. CYP2E1 plays a role in the toxicity of ethanol, carcinogens and certain drugs. Inhibition of autophagy increased ethanol-toxicity and accumulation of fat in wild type and CYP2E1 knockin mice but not in CYP2E1 knockout mice as well as in HepG2 cells expressing CYP2E1 (E47 cells) but not HepG2 cells lacking CYP2E1 (C34 cells). The goal of the current study was to evaluate whether modulation of autophagy can affect CYP2E1-dependent cytotoxicity in the E47 cells. The agents used to promote CYP2E1 –dependent toxicity were a polyunsaturated fatty acid, arachidonic acid (AA), buthionine sulfoximine (BSO), which depletes GSH, and CCl4, which is metabolized to the CCl3 radical. These three agents produced a decrease in E47 cell viability which was enhanced upon inhibition of autophagy by 3-methyladenine (3-MA) or Atg 7 siRNA. Toxicity was lowered by rapamycin which increased autophagy and was much lower to the C34 cells which do not express CYP2E1. Toxicity was mainly necrotic and was associated with an increase in reactive oxygen production and oxidative stress; 3-MA increased while rapamycin blunted the oxidative stress. The enhanced toxicity and ROS formation produced when autophagy was inhibited was prevented by the antioxidant N-Acetyl cysteine. AA, BSO and CCl4 produced mitochondrial dysfunction, lowered cellular ATP levels and elevated mitochondrial production of ROS. This mitochondrial dysfunction was enhanced by inhibition of autophagy with 3-MA but decreased when autophagy was increased by rapamycin. The mitogen activated protein kinases p38 MAPK and JNK were activated by AA especially when autophagy was inhibited and chemical inhibitors of p38 MAPK and JNK lowered the elevated toxicity of AA produced by 3-MA. These results show that autophagy was protective against the toxicity produced by several agents known to be activated by CYP2E1. Since CYP2E1 plays an important role in the toxicity of ethanol, drugs and carcinogens and is activated under various pathophysiological conditions such as diabetes, NASH and obesity, attempts to stimulate autophagy may be beneficial in preventing/lowering CYP2E1/ethanol liver injury. Inhibition of autophagy in HepG2 E47 cells which express CYP2E1 promotes AA, BSO and CCl4 toxicity. Decreased autophagy in E47 cells increased reactive oxygen production and oxidative stress and potentiated mitochondrial dysfunction. The inhibition of autophagy enhanced activation of p38 MAPK and JNK by AA and this activation contributed to the toxicity. Autophagy is protective against the toxicity produced by agents known to be activated by CYP2E1.
登录
查看更多内容
影响因子：
4.3
作者：
Jimenez-Lopez, Jose M;Cederbaum, Arthur I
通讯作者：
Cederbaum, Arthur I
影响因子：
25.7
作者：
Butura, Angelica;Nilsson, Kerstin;Ingelman-Sundberg, Magnus
通讯作者：
Ingelman-Sundberg, Magnus
通过自噬调节脂质液滴。
影响因子：
10.9
作者：
Dong, Hanqing;Czaja, Mark J.
通讯作者：
Czaja, Mark J.
影响因子：
3.8
作者：
Bai, Jingxiang;Cederbaum, Arthur I.
通讯作者：
Cederbaum, Arthur I.
影响因子：
11.4
作者：
Haberzettl, Petra;Hill, Bradford G.
通讯作者：
Hill, Bradford G.