Quan Ying-Yao, Qin Gui-Qi, Huang Hao, Liu Yu-Hong, Wang Xiao-Ping, Chen Tong-Sheng
Department of Pain Management, the First Affiliated Hospital of Jinan University, Guangzhou, China.
MOE Key Laboratory of Laser Life Science & College of Life Science, South China Normal University, Guangzhou, China.
Free Radic Biol Med. 2016 May;94:135-44. doi: 10.1016/j.freeradbiomed.2016.02.026. Epub 2016 Feb 24.
Sodium nitroprusside (SNP) has been widely used as an exogenous nitric oxide (NO) donor to explore the molecular mechanism of NO-mediated chondrocyte apoptosis during the latest two decades. We have recently found that NO-independent ROS play a key role in SNP-induced apoptosis in rabbit chondrocytes. This study aims to investigate what kind of ROS and how the reliable ROS mediators mediate the SNP-induced apoptosis. Data shows that SNP and NO-exhausted SNP (SNPex) induced ROS production or cytotoxicity to identically degree. SNP induced a marked increase in iron ions, superoxide anion (O2(•-)), hydrogen peroxide (H2O2) and hydroxyl radical ((•)OH) level. H2O2 scavenger (CAT) and (•)OH scavenger (DMSO) significantly inhibited SNP-induced chondrocyte apoptosis. Iron ions chelator (DFO) entirely prevented SNP-induced chondrocyte apoptosis. In contrast, O2(•-) scavenger (SOD) and glutathione depletion agent (BSO) promoted SNP-induced cytotoxicity. K3[Fe(CN)6] exhibited no cytotoxicity, and H2O2 alone up to 250µM or iron ions alone up to 90µM is non-cytotoxic to chondrocytes. Combination of 25µM FeSO4 and 100µM H2O2 in the presence of BSO induced chondrocyte death similar to SNP treatment. Fetal bovine serum (FBS) enhanced iron ions release from SNP and the cytotoxicity of SNP. Our data shows that the extracellular Fenton reaction between iron ions released from SNP and H2O2 induced by SNP plays a key role in SNP-induced chondrocyte apoptosis. Overall, our results indicate that the potential of SNP to increase iron ions and ROS should be especially considered for some biological functions and, possibly, also for clinical applications of this drug.
在过去二十年中，硝普钠（SNP）作为一种外源性一氧化氮（NO）供体被广泛用于探索NO介导的软骨细胞凋亡的分子机制。我们最近发现，不依赖NO的活性氧（ROS）在SNP诱导的兔软骨细胞凋亡中起关键作用。本研究旨在探讨何种ROS以及可靠的ROS介质如何介导SNP诱导的凋亡。数据显示，SNP和耗尽NO的SNP（SNPex）诱导ROS产生或细胞毒性的程度相同。SNP诱导铁离子、超氧阴离子（O2(•-)）、过氧化氢（H2O2）和羟基自由基（(•)OH）水平显著升高。H2O2清除剂（CAT）和(•)OH清除剂（DMSO）显著抑制SNP诱导的软骨细胞凋亡。铁离子螯合剂（DFO）完全阻止SNP诱导的软骨细胞凋亡。相反，O2(•-)清除剂（SOD）和谷胱甘肽消耗剂（BSO）促进SNP诱导的细胞毒性。铁氰化钾（K3[Fe(CN)6]）无细胞毒性，单独高达250µM的H2O2或单独高达90µM的铁离子对软骨细胞无细胞毒性。在BSO存在下，25µM硫酸亚铁（FeSO4）和100µM H2O2的组合诱导软骨细胞死亡，类似于SNP处理。胎牛血清（FBS）增强了SNP中铁离子的释放和SNP的细胞毒性。我们的数据表明，SNP释放的铁离子与SNP诱导的H2O2之间的细胞外芬顿反应在SNP诱导的软骨细胞凋亡中起关键作用。总体而言，我们的结果表明，对于该药物的某些生物学功能以及可能的临床应用，应特别考虑SNP增加铁离子和ROS的潜力。
