Wang Honglin, Wang Zhilun, Chen Jinghong, Wu Jin
Institute of Endemic Diseases, Medical School of Xi'an Jiaotong University, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an 710061, Shaanxi, China.
Cell Biol Int. 2007 Sep;31(9):1027-35. doi: 10.1016/j.cellbi.2007.03.017. Epub 2007 Mar 20.
Nitric oxide (NO), reported as an important inducer of apoptosis, plays a considerable role in the pathogenetic mechanisms of articular diseases. This research aimed at investigating the role of p38 MAPK signal transduction pathway on apoptosis induced by NO in rabbit articular chondrocytes. In the present study, NO was produced by a novel NO donor NOC-18. Rabbit articular chondrocytes were cultured as monolayer, and the first passage cells were used for the experiments. We detected apoptosis induced by NO using Annexin V-FITC/PI flow cytometry and TUNEL assay. Measurement of caspase-3 has reflected its activity level. Western blotting was performed to show the protein expressions of p38, NF-kappaB, p53 and caspase-3. Furthermore, we examined the inhibitory effects in the NO pathway with p38-specific inhibitor SB203580. Treatment with NOC-18 caused accelerated apoptosis in a concentration dependent manner. This acceleration was able to be reduced when added to SB203580. Besides, the inhibitor could significantly decrease NO-induced p38, NF-kappaB, p53 and caspase-3 protein expressions, as well as caspase-3 intracellular activity (P<0.05). These results suggest that p38 MAPK signal transduction pathway is critical to NO-induced chondrocyte apoptosis, and p38 plays a role by way of stimulating NF-kappaB, p53 and caspase-3 activation.
一氧化氮（NO）被报道为细胞凋亡的重要诱导剂，在关节疾病的发病机制中发挥着重要作用。本研究旨在探讨p38丝裂原活化蛋白激酶（MAPK）信号转导通路在NO诱导兔关节软骨细胞凋亡中的作用。在本研究中，新型NO供体NOC-18产生NO。兔关节软骨细胞进行单层培养，第一代传代细胞用于实验。我们使用膜联蛋白V-异硫氰酸荧光素/碘化丙啶（Annexin V-FITC/PI）流式细胞术和末端脱氧核苷酸转移酶介导的缺口末端标记法（TUNEL法）检测NO诱导的细胞凋亡。半胱天冬酶-3（caspase-3）的检测反映了其活性水平。采用蛋白质免疫印迹法检测p38、核因子κB（NF-κB）、p53和caspase-3的蛋白表达。此外，我们用p38特异性抑制剂SB203580检测其对NO通路的抑制作用。用NOC-18处理以浓度依赖性方式导致细胞凋亡加速。当加入SB203580时，这种加速作用能够被降低。此外，该抑制剂可显著降低NO诱导的p38、NF-κB、p53和caspase-3蛋白表达以及caspase-3细胞内活性（P<0.05）。这些结果表明，p38 MAPK信号转导通路对NO诱导的软骨细胞凋亡至关重要，p38通过刺激NF-κB、p53和caspase-3活化发挥作用。
