Activation of ERK or inhibition of JNK ameliorates H2O2 cytotoxicity in mouse renal proximal tubule cells
Activation of ERK or inhibition of JNK ameliorates H2O2 cytotoxicity in mouse renal proximal tubule cells
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DOI：
10.1111/j.1523-1755.2004.00500.x
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发表时间：
2004-04-01
影响因子：
19.6
通讯作者：
Safirstein, RL
中科院分区：
文献类型：
--
作者：
Arany, I;Megyesi, JK;Safirstein, RL
背景我们以前的研究表明，细胞外信号调节激酶（ERK）和c-Jun N-末端/应激激活蛋白激酶（JNK）的激活之间的平衡可能决定细胞在体内氧化损伤后的命运。采用小鼠近曲小管细胞系（TKPTS）研究过氧化氢（H2 O2）诱导的死亡和存活。ERK和JNK在这一过程中的作用进行了研究，通过使用腺病毒，含有组成型活性丝裂原活化蛋白激酶1（MEK 1）或显性负性JNK。吖啶橙子加溴化乙锭染色用于区分H2 O2处理后的活细胞、凋亡细胞和坏死细胞。我们通过荧光激活细胞分选仪（FACS）分析细胞周期事件，通过Western印迹分析ERK和JNK的磷酸化状态。TKPTS细胞在中等水平的氧化应激（0.5 mmol/L H2 O2）下通过暂时的生长停滞存活，而高剂量H2 O2（1 mmol/L）引起广泛坏死。生存与ERK和JNK的激活相关，而死亡仅与JNK激活相关。在1 mmol/L H2 O2处理后，腺病毒介导的ERK上调或JNK功能抑制可使TKPTS细胞的存活率分别增加8倍或7倍。有趣的是，ERK激活，因此，生存与生长停滞，而不是增殖。我们证明，氧化损伤引起的坏死可以通过上调内源性ERK或抑制JNK相关通路来改善。这些结果直接表明，促生存和促死亡丝裂原活化蛋白激酶（MAPKs）之间的细胞内平衡决定近端小管细胞的生存从氧化损伤，并揭示可能的介质的生存。
Background. Our previous studies suggest that the balance between the activation of extracellular signal-regulated kinase (ERK) and the c-Jun N-terminal/stress-activated protein kinase (JNK) might determine cell fate following oxidant injury in vivo.Methods. The mouse proximal tubule cell line (TKPTS) was used to study hydrogen peroxide (H2O2)-induced death and survival. The role of ERK and JNK in this process was studied by using adenoviruses that contain either a constitutively active mitogen-activated protein kinase kinase 1 (MEK1) or a dominant-negative JNK. Acridine orange plus ethidium bromide staining was applied to distinguish between viable, apoptotic, and necrotic cells following H2O2 treatment. We analyzed cell cycle events by fluorescence-activated cell sorter (FACS) analysis and the phosphorylation status of ERK and JNK by Western blotting.Results. TKPTS cells survived a moderate level of oxidative stress (0.5 mmol/L H2O2) via temporary growth arrest, while high dose of H2O2 (1 mmol/L) caused extensive necrosis. Survival was associated with activation of both ERK and JNK, while death was associated with JNK activation only. Prior adenovirus-mediated up-regulation of ERK or inhibition of JNK function increased the survival (8- or 7-fold, respectively) of TKPTS cells after 1 mmol/L H2O2 treatment. Interestingly, ERK activation and, thus, survival was associated with growth arrest not proliferation.Conclusion. We demonstrate that oxidant injury-induced necrosis could be ameliorated by either up-regulation of endogenous ERK or by inhibition of JNK-related pathways. These results directly demonstrate that the intracellular balance between prosurvival and prodeath mitogen-activated protein kinases (MAPKs) determine proximal tubule cell survival from oxidant injury and reveal possible mediators of survival.