A novel TXNIP-based mechanism for Cx43-mediated regulation of oxidative drug injury.
A novel TXNIP-based mechanism for Cx43-mediated regulation of oxidative drug injury.
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一种基于 TXNIP 的新机制，用于 Cx43 介导的氧化药物损伤调节。
DOI：
10.1111/jcmm.12641
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发表时间：
2015-10
影响因子：
5.3
通讯作者：
Yao J
中科院分区：
文献类型：
--
作者：
Gao K;Chi Y;Zhang X;Zhang H;Li G;Sun W;Takeda M;Yao J
缝隙连接(GJS)在调节细胞对多种药物的反应中起着重要作用。然而，人们对它们的机制知之甚少。利用G418诱导的细胞毒性体外模型，我们探索了可能涉及的信号机制。细胞与G418孵育导致细胞死亡，表现为细胞形态的改变、细胞活力的丧失和caspase-3的激活。在细胞损伤发生之前，G418诱导了ROS的产生，激活了氧化敏感蛋白P38，导致连接蛋白43(Cx43)从非磷酸化状态转变为过度磷酸化状态。这些变化在很大程度上被抗氧化剂阻止，这表明存在氧化应激。用抑制剂或siRNA下调Cx43的表达，抑制硫氧还蛋白相互作用蛋白(TXNIP)的表达，激活Akt，保护细胞免受G418的毒性。进一步分析表明，siRNA抑制TXNIP激活了Akt，并再现了Cx43抑制剂的保护作用，而Akt敏化细胞对G418的毒性有抑制作用。此外，TXNIP/Akt的干扰也影响了嘌呤霉素和阿霉素诱导的细胞损伤。因此，我们的研究表明，TXNIP是一种目前尚未被认识的分子，与Cx43对药物氧化损伤的调节作用有关。靶向Cx43/TXNIP/Akt信号转导通路可能是调节细胞对药物反应的一种有前途的方法。
Gap junctions (GJs) play an important role in the regulation of cell response to many drugs. However, little is known about their mechanisms. Using an in vitro model of cytotoxicity induced by geneticin (G418), we explored the potential signalling mechanisms involved. Incubation of cells with G418 resulted in cell death, as indicated by the change in cell morphology, loss of cell viability and activation of caspase-3. Before the onset of cell injury, G418 induced reactive oxygen species (ROS) generation, activated oxidative sensitive kinase P38 and caused a shift of connexin 43 (Cx43) from non-phosphorylated form to hyperphosphorylated form. These changes were largely prevented by antioxidants, suggesting an implication of oxidative stress. Downregulation of Cx43 with inhibitors or siRNA suppressed the expression of thioredoxin-interacting protein (TXNIP), activated Akt and protected cells against the toxicity of G418. Further analysis revealed that inhibition of TXNIP with siRNA activated Akt and reproduced the protective effect of Cx43-inhibiting agents, whereas suppression of Akt sensitized cells to the toxicity of G418. Furthermore, interference of TXNIP/Akt also affected puromycin- and adriamycin-induced cell injury. Our study thus characterized TXNIP as a presently unrecognized molecule implicated in the regulatory actions of Cx43 on oxidative drug injury. Targeting Cx43/TXNIP/Akt signalling cascade might be a promising approach to modulate cell response to drugs.