Apoptotic insults to human chondrocytes induced by sodium nitroprusside are involved in sequential events, including cytoskeletal remodeling, phosphorylation of mitogen-activated protein kinase kinase kinase-1/c-Jun N-terminal kinase, and Bax-mitochondria-mediated caspase activation
Apoptotic insults to human chondrocytes induced by sodium nitroprusside are involved in sequential events, including cytoskeletal remodeling, phosphorylation of mitogen-activated protein kinase kinase kinase-1/c-Jun N-terminal kinase, and Bax-mitochondria-mediated caspase activation
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DOI：
10.1002/jor.20578
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发表时间：
2008-07-01
影响因子：
2.8
通讯作者：
Chen, Ruei-Ming
中科院分区：
文献类型：
--
作者：
Cherng, Yih-Giun;Chang, Hua-Chia;Chen, Ruei-Ming
一氧化氮（NO）可以调节软骨细胞的活性。本研究旨在探讨一氧化氮供体硝普钠（SNP）对人软骨细胞损伤的分子机制。暴露于SNP的人软骨细胞增加细胞NO水平，但以浓度和时间依赖的方式降低细胞活力。SNP时间依赖性诱导DNA断裂和细胞凋亡。用NO清除剂2-苯基-4,4,5,5-四甲基-咪唑啉-1-氧基- 3-氧化物处理可显著降低snp诱导的细胞损伤。SNP干扰f -肌动蛋白和微管细胞骨架，刺激丝裂原活化蛋白激酶激酶激酶1 （MEKK1）和c-Jun n末端激酶（JNK）的磷酸化。与SNP类似，f -肌动蛋白形成抑制剂细胞松弛素D会干扰f -肌动蛋白聚合，增加MEKK1和JNK的激活。人软骨细胞中MEKK1显性阴性突变体（dnMEK1）的过表达可显著改善snp诱导的细胞凋亡。暴露于SNP促进了Bax从细胞质向线粒体的易位，但应用dnMEKK1降低了易位。SNP时间依赖性地降低了线粒体膜电位、复合体I NADH脱氢酶活性和细胞ATP水平，但增加了细胞色素c从线粒体向细胞质的释放。给药后caspase-9、-3和-6的活性依次升高。本研究表明，SNP可通过细胞骨架重塑、MEKK1/JNK激活、Bax易位、线粒体功能障碍、细胞色素c释放、caspase激活和DNA断裂等一系列事件诱导人软骨细胞凋亡。(C) 2008年中国骨科学会。Wiley期刊公司出版。
Nitric oxide (NO) can regulate chondrocyte activities. This study was aimed to evaluate the molecular mechanisms of NO donor sodium nitroprusside (SNP)-induced insults to human chondrocytes. Exposure of human chondrocytes to SNP increased cellular NO levels but decreased cell viability in concentration- and time-dependent manners. SNP time dependently induced DNA fragmentation and cell apoptosis. Treatment with 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl 3-oxide, an NO scavenger, significantly lowered SNP-induced cell injuries. Administration of SNP interrupted F-actin and microtubule cytoskeletons and stimulated phosphorylation of mitogen-activated protein kinase kinase kinase-1 (MEKK1) and c-Jun N-terminal kinase (JNK). Similar to SNP, cytochalasin D, an inhibitor of F-actin formation, disturbed F-actin polymerization and increased MEKK1 and JNK activations. Overexpression of a dominant negative mutant of MEKK1 (dnMEK1) in human chondrocytes significantly ameliorated SNP-induced cell apoptosis. Exposure to SNP promoted Bax translocation from the cytoplasm to mitochondria, but application of dnMEKK1 lowered the translocation. SNP time dependently decreased the mitochondrial membrane potential, complex I NADH dehydrogenase activity, and cellular ATP levels, but increased the release of cytochrome c from mitochondria to the cytoplasm. Activities of caspase-9, -3, and -6 were sequentially increased by SNP administration. This study shows that SNP can induce apoptosis of human chondrocytes through sequential events, including cytoskeletal remodeling, activation of MEKK1/JNK, Bax translocation, mitochondrial dysfunction, cytochrome c release, caspase activation, and DNA fragmentation. (C) 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.