Ortiz E M, Dusetti N J, Vasseur S, Malka D, Bödeker H, Dagorn J C, Iovanna J L
Unité de Recherches de Physiologie et Pathologie Digestives, INSERM Unité 315, Marseille, France.
Gastroenterology. 1998 Apr;114(4):808-16. doi: 10.1016/s0016-5085(98)70595-5.
BACKGROUND & AIMS: Free radicals are involved in the pathogenesis of acute pancreatitis, during which pancreatitis-associated protein (PAP)-I is overexpressed. We explored whether PAP-I expression could be induced by oxidative stress and whether it could affect apoptosis.
AR4-2J cells were exposed to H2O2 or menadione, and PAP-I messenger RNA (mRNA) expression was analyzed by Northern blotting.
Maximal expression was observed with 0.1 mmol/L H2O2 or with 0.05 mmol/L menadione. Induction was detectable after 12 hours, reached a climax at 18 hours, and then decreased. Pretreatment of the cells with pyrrolidine dithiocarbamate completely abolished PAP-I mRNA induction, suggesting involvement of NFkappaB in the signaling pathway. These findings were confirmed in transient transfection assays using a plasmid containing the PAP-I promoter linked to the chloramphenicol acetyltransferase reporter gene. Then the relationship between PAP-I induction and protection against cell damage during oxidative stress was considered. Constitutive PAP-I expression in AR4-2J cells after transfection with PAP-I complementary DNA conferred significant resistance to apoptosis induced by low doses of H2O2 but not to necrosis induced by high doses of H2O2.
These results suggest that during oxidative stress, PAP-I might be part of a mechanism of pancreatic cell protection against apoptosis.
自由基参与急性胰腺炎的发病机制，在此过程中胰腺炎相关蛋白（PAP）-I过度表达。我们探究了PAP-I的表达是否可由氧化应激诱导，以及它是否会影响细胞凋亡。
将AR4-2J细胞暴露于过氧化氢（H2O2）或甲萘醌中，通过Northern印迹法分析PAP-I信使核糖核酸（mRNA）的表达。
在0.1 mmol/L H2O2或0.05 mmol/L甲萘醌作用下观察到最大表达。诱导在12小时后可检测到，在18小时达到高峰，然后下降。用吡咯烷二硫代氨基甲酸盐预处理细胞可完全消除PAP-I mRNA的诱导，提示核因子κB（NFκB）参与信号通路。这些发现在用含有与氯霉素乙酰转移酶报告基因相连的PAP-I启动子的质粒进行的瞬时转染试验中得到证实。然后考虑了PAP-I诱导与氧化应激期间细胞损伤保护之间的关系。用PAP-I互补DNA转染后AR4-2J细胞中组成性PAP-I表达赋予对低剂量H2O2诱导的细胞凋亡的显著抗性，但对高剂量H2O2诱导的坏死无抗性。
这些结果表明，在氧化应激期间，PAP-I可能是胰腺细胞抗凋亡保护机制的一部分。
