Objective: To explore the protective effect and its molecular mechanism of apoptosis signal-regulating kinase 1 (ASK1) inhibitor (GS-459679) on acetaminophen-induced liver injury in mice. Methods: The model of liver injury was established by administration of acetaminophen (APAP) (300 mg/kg, i.p.) on C57BL/6 mice. Forty-eight male C57BL/6 mice were randomly divided into four groups, consisting of control group, GS group (GS-459679, 30 mg/kg, i.p.), APAP-induced group, and GS combined with APAP-induced group. For GS combined with APAP-induced group, mice were treated with GS 30 min prior to administration of APAP. After mice were euthanized at 6 h or 12 h, respectively, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed, and mRNA levels of TNF-α, IL-6 and IL-1β were tested. The activity of glutathione (GSH), oxidized GSH (GSSG) and malondialdehyde were quantified. In addition, ASK1, P-ASK1, JNK and P-JNK protein levels were tested in all groups. Results: The ASK1 and P-ASK1 levels were up-regulated in APAP-induced group. Compared to the control group, serum levels of ALT and AST, and mRNA levels of TNF-α, IL-6 and IL-1β were increased in APAP-induced group. Meanwhile, the levels of MAD and GSSG, and the ratio of GSSG/GSH were higher and the JNK was activatedin APAP-induced group compared with that in control group. However, compared to APAP-induced group, GS combined with APAP-induced group displayed a decrease of protein expression levels of ASK1, P-ASK1 and P-JNK, a reduction of serum levels of ALT and AST, a decrease in TNF-α, IL-6 and IL-1β mRNA levels, and a low ration of GSSG/GSH. Conclusions: GS-459679 treatment effectively down-regulates ASK1 and P-ASK1 expression. Addition of GS-459679 decreases the generation of liver metabolites and inflammatory factors, reduces oxidative stress reaction, inhibits JNK activation, and then protects the responsiveness to APAP-induced liver injury.

[摘 要] 目的：探讨DJ-1基因过表达对人胃癌MGC803细胞增殖、迁移、侵袭与上皮间质转化（EMT）的影响及其机制。方法：利用基因转染技术构建DJ-1基因过表达MGC803细胞，实验分为MGC803、空载体和DJ-1过表达组。采用MTT、平板克隆形成、细胞划痕和Transwell实验分别检测DJ-1过表达对MGC803细胞增殖、克隆形成、迁移与侵袭的影响；qPCR和WB法检测DJ-1过表达对各组细胞DJ-1、PTEN、Akt、p-Akt、Snail、vimentin、E-cadherin、MMP-9与TIMP-3表达的影响，相差显微镜下观察MGC803细胞形态学的变化。裸鼠荷瘤实验检测DJ-1过表达对MGC803细胞移植瘤体内生长的影响。结果：成功构建DJ-1基因稳定过表达的MGC803细胞。与MGC803组和空载体组比较，DJ-1过表达组细胞的增殖能力与克隆形成数均显著增加（均P<0.05），细胞迁移距离明显增加、划痕距离明显缩短（均P<0.05），迁移与侵袭细胞数显著增多（均P<0.05），DJ-1 mRNA与蛋白表达明显上调、PTEN mRNA与蛋白表达下调（均P<0.05），Akt总蛋白各组比较无明显差异（均P>0.05），p-Akt蛋白表达明显上调（P<0.05），Snail、vimentin与MMP-9表达上调、E-cadherin与TIMP-3表达下调（均P<0.05）。相差显微镜下见长梭形细胞数目增多，圆形与椭圆形细胞减少，异型性更为明显。荷瘤裸鼠体内实验结果表明，与MGC803组相比较，DJ-1过表达组MGC803细胞移植瘤生长速度明显加快、移植瘤质量显著增加（均P<0.05）。结论：DJ-1过表达可通过PTEN/Akt通路在体内外抑制MGC803细胞的增殖、迁移、侵袭与EMT。