Macrophages resistant to endogenously generated nitric oxide-mediated apoptosis are hypersensitive to exogenously added nitric oxide donors: Dichotomous apoptotic response independent of caspase 3 and reversal by the mitogen-activated protein kinase kinase (MEK) inhibitor PD 098059
Macrophages resistant to endogenously generated nitric oxide-mediated apoptosis are hypersensitive to exogenously added nitric oxide donors: Dichotomous apoptotic response independent of caspase 3 and reversal by the mitogen-activated protein kinase kinase (MEK) inhibitor PD 098059
复制标题
DOI：
10.1073/pnas.95.9.5045
复制
发表时间：
1998-04-28
影响因子：
11.1
通讯作者：
Lapetina, EG
中科院分区：
文献类型：
--
作者：
Mohr, S;McCormick, TS;Lapetina, EG
一氧化氮合酶(NO)通过诱导型一氧化氮合酶诱导巨噬细胞死亡。我们证明，与亲代RAW 264.7细胞相比，暴露在外源性NO供体的巨噬细胞中，与亲代RAW 264.7细胞相比，暴露于外源性NO供体会导致对诱导型一氧化氮合酶(RES细胞)诱导的凋亡产生抵抗。外源性NO供体诱导的细胞凋亡不依赖于caspase3。尽管caspase3活性在凋亡的巨噬细胞中被刺激，但用抑制剂DEVD-CHO(N-乙酰-天冬氨酸-谷氨酸-Val-天冬氨酸醛)抑制caspase3并不能逆转NO供体S亚硝基谷胱甘肽(GSNO)诱导的凋亡，这表明尽管caspase3活性在巨噬细胞凋亡过程中被激活，但这一信号不足以诱导凋亡，酶聚(腺苷二磷酸核糖)聚合酶的切割反映了我们对caspase活性的研究结果。有趣的是，我们发现外源性NO捐献导致细胞在G(2)/M期边界聚集。在这里，我们证明了丝裂原激活的蛋白激酶抑制剂PD 098059可以逆转G(2)/M期阻滞，并表明这种处理也抑制了观察到的RES巨噬细胞的凋亡，用MEK抑制剂处理还逆转了GSNO处理的细胞的caspase3活性和多聚腺苷二磷酸核糖聚合酶的切割，这一结果表明丝裂原激活的蛋白激酶通路可能参与了caspase级联的调节。我们的结果表明，通过抵抗内源性NO来选择巨噬细胞，可能会导致对外源性NO供体的超敏反应。这些发现对癌症和动脉粥样硬化中可能出现的抗凋亡细胞群的治疗具有相关的意义。
Nitric oxide (NO) induction through the inducible NO synthase has been demonstrated to cause cell death in macrophages. We demonstrate that, in macrophages that have been rendered resistant to apoptosis induced by inducible NO synthase (RES cells), exposure to exogenous NO donors results in a hypersensitive apoptosis reaction when compared with the parental RAW 264.7 cells. The apoptosis induced via exogenous NO donors was found to be caspase 3-independent. Although caspase 3 activity was stimulated in the apoptotic macrophages, inhibition of caspase 3 by the inhibitor DEVD-CHO (N-acetyl-Asp-Glu-Val-Asp-aldehyde) did not reverse the apoptosis induced by the NO donor S-nitrosoglutathione (GSNO), This suggests that although caspase 3 activity is stimulated during apoptosis in macrophages, this signal is not sufficient to induce apoptosis, Cleavage of the enzyme poly(ADP ribose) polymerase mirrors our results of the caspase activity. Interestingly, we show that exogenous NO donation results in an accumulation of cells at the G(2)/M-phase border. Here, we demonstrate that the mitogen activated protein kinase kinase (MEK) inhibitor PD 098059 can be used to reverse the G(2)/M-phase block and show that this treatment also inhibits the observed apoptosis in RES macrophages, Treatment with the MEK inhibitor also reversed both the caspase 3 activity and poly(ADP ribose) polymerase cleavage in cells treated with GSNO, This result indicates that the mitogen-activated protein kinase pathway may be involved in regulation of the caspase cascade. Alternatively, it may suggest an activity for the MEK inhibitor heretofore not observed, that of a cyclin kinase inhibitor, Our results suggest that selection of macrophages by resistance to endogenously generated NO may cause hypersensitivity to exogenous NO donors. These findings have relevant implications for the treatment of apoptotic-resistant cell populations that may occur in both cancer and atheroma.